# Analysis of the Distribution and Antibiotic Resistance of Pathogens Causing Infections in Hospitals from 2017 to 2019

Authors: Guoliang Liu; Mingzhao Qin
Journal: Evidence-Based Complementary and Alternative Medicine
 (2022)

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## Abstract

Background. Antibiotic resistance is a global public health problem, leading to high mortality and treatment costs. To achieve more efficient treatment protocols and better patient recovery, the distribution and drug resistance of pathogens in our hospital were investigated, allowing significant clinical guidance for the use of antimicrobials. Methods. In this retrospective study (2017–2019), 3482 positive samples were isolated from 43,981 specimens in 2017; 3750 positive specimens were isolated from 42,923 specimens in 2018; and 3839 positive pathogens were isolated from 46,341 specimens in 2019. These samples were from various parts of the patients, including the respiratory tract, urine, blood, wound secretions, bile, and puncture fluids. The distribution and antibiotic resistance of these isolated pathogens from the whole hospital were analyzed. Results. The results from pathogen isolation showed that Escherichia coli (12.8%), Staphylococcus aureus (11%), Klebsiella pneumoniae (10.8%), Pseudomonas aeruginosa (10.7%), and Acinetobacter baumannii (6.4%) represented the five main pathogenic bacteria in our hospital. Pseudomonas aeruginosa (16.2% and 17.5%) occupied the largest proportion in the central intensive care unit (central ICU) and respiratory intensive care unit (RICU), while Acinetobacter baumannii (15.4%) was the most common pathogen in the emergency intensive care unit (EICU). The resistance rate of Escherichia coli to trimethoprim and minocycline was 100%, and the sensitivity rate to ertapenem, furantoin, and amikacin was above 90%. The resistance rate of Pseudomonas aeruginosa to all antibiotics, such as piperacillin and ciprofloxacin, was under 40%. The sensitivity rate of Acinetobacter baumannii to tigecycline and minocycline was less than 30%, and the resistance rate to many drugs such as piperacillin, ceftazidime, and imipenem was above 60%. Extended-spectrum β-lactamases (ESBLs)-producing Klebsiella pneumoniae (ESBLs-KPN) and carbapenem-resistant Klebsiella pneumoniae (CRE-KPN), ESBLs-producing Escherichia coli (ESBLs-ECO) and carbapenem-resistant Escherichia coli (CRE-ECO), multidrug-resistant Acinetobacter baumannii (MDR-AB), multidrug-resistant Pseudomonas aeruginosa (MDR-PAE), and methicillin-resistant Staphylococcus aureus (MRSA) are all important multidrug-resistant bacteria found in our hospital. The resistance rate of ESBLs-producing Enterobacteriaceae to ceftriaxone and amcarcillin-sulbactam was above 95%. CRE Enterobacteriaceae bacteria showed the highest resistance to amcarcillin-sulbactam (97.1%), and the resistance rates of MDR-AB to cefotaxime, cefepime, and aztreonam were 100%. The resistance rates of MDR-PAE to ceftazidime, imipenem, and levofloxacin were 100%, and the sensitivity rate to polymyxin B was above 98%. The resistance rate of MRSA to oxacillin was 100%, and the sensitivity rate to linezolid and vancomycin was 100%. Conclusion. The distribution of pathogenic bacteria in different hospital departments and sample sources was markedly different. Therefore, targeted prevention and control of key pathogenic bacteria in different hospital departments is necessary, and understanding both drug resistance and multiple drug resistance of the main pathogenic bacteria may provide guidance for the rational use of antibiotics in the clinic.


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## Body

## 1. Introduction

Due to the complexity and universality of infectious diseases, antibacterial agents have been widely used in clinical practice. Since the application of antibacterial agents in clinical practice, they have saved the lives of countless patients. However, bacterial resistance caused by overuse not only has a negative impact on individual users but also on the social group as a whole. Globally, various institutes and agencies have recognized this serious public health issue. Antibiotics are a subset of antimicrobial agents that play a key role in the inhibition of essential bacterial functions and are used widely to treat and prevent bacterial infections in humans and other animals [1]. Treatment by antibiotics is one of the main approaches used by modern medicine to combat infectious diseases [2]. Antibiotics have not only saved countless lives but also have played a pivotal role in achieving significant advances in medicine and surgery and have successfully prevented or treated infections that occur in patients [3]. However, antibiotic resistance has emerged because of their overuse and inappropriate prescribing, as well as their extensive use in agriculture [4]. A minimum of 700,000 people die from antimicrobial-resistant infections each year around the world, and drug-resistant infections are expected to kill 10 million people a year within 30 years, greatly exceeding deaths from cancer. It has also been estimated that this resistance problem will be the biggest challenge facing healthcare systems by 2050 [1]. The rapid and sustained spread of antibiotic resistance poses a growing threat to the public, animal, and environmental health worldwide. The abuse of antibiotics in clinical practice, poor public health conditions, and insufficient public awareness are the main causes cited [5].Multidrug resistance (MDR) relates to bacteria becoming resistant to multiple classes of antibiotics and [6, 7] is now classified as follows: multidrug resistance (MDR) that is not susceptible to at least one representative from each of the three categories of selected antimicrobial compound families [7]. Extreme drug resistance (XDR) is not susceptible to at least a single representative of all but very few categories of antimicrobial compounds. Pan-drug resistance (PDR) is not susceptible to any of the tested representatives of all known antimicrobial compound families [7]. Compared with other infections, MDR infections are associated with poorer clinical outcomes, resulting in increased morbidity and mortality rates and higher healthcare costs [8]. There is concern that the emergence of pan-resistant strains (pathogens resistant to all available antibiotics) will render some infections untreatable. How to effectively slow down the emergence of multidrug-resistant bacteria and block the spread of multidrug-resistant bacteria has attracted extensive attention from the medical community, government, and society.In this study, the isolation, culture, and identification of pathogenic microorganisms and antimicrobial sensitivity tests were carried out, the detection results for different pathogenic microorganisms were provided, and the changes to and the mechanism of drug resistance were analyzed. This study provides a theoretical basis for exploring the clinical application of antibacterial drugs and further monitoring bacterial resistance and multidrug-resistant bacteria.


## 2. Samples and Methods

### 2.1. Source of Pathogenic Samples

Pathogen samples, including sputum, mid-section urine, blood, wound secretions, chest and gastric juices, bile, and puncture fluids, were taken from hospitalized patients from 2017 to 2019. To avoid overestimating antibiotic resistance, duplicate strains obtained from the same patient were deleted from the study. The study protocol was approved by the Ethics Committee of our hospital and given that medical records and patient information were anonymously reviewed and collected in this observational study, informed consent was not needed.In 2017, the total number of microbial culture samples submitted for inspection was 43,981, and the top five infection sites were the lower respiratory tract (271/28.65%), urinary tract (125/13.21%), upper respiratory tract (107/11.31%), eyes, ears, and oral cavities (67/7.08%), and blood (64/6.77%). Respiratory tract infection, however, has always represented the main site of infection.In 2018, the total number of microbial culture samples submitted for inspection was 42,923, a slight decrease from last year. The respiratory tract, urine, blood, stool, and female reproductive tract samples ranked in the top five, of which the respiratory tract samples, urine specimens, and blood specimens accounted for 43.93%, 12.35%, and 9.98% of the total, respectively. Stool specimens accounted for 6.73%, and female reproductive tract specimens accounted for 6.12%, a significant increase from last year by 4% and were related toStreptococcus agalactiae screening in obstetrics and gynecology.The total number of microbial culture specimens submitted for inspection in 2019 was 46,341, also representing an increase from last year. The lower respiratory tract, urine, and blood specimens ranked in the top three, accounting for 39.6%, 11.0%, and 8.8% of the total, respectively, and the female reproductive tract specimens accounted for 6.7%, an increase of 6.12% from 2018. The main reason is related toStreptococcus agalactiae screening in the obstetrics and gynecology department, and stool specimens accounted for 6.5% and were related to the decline in the number of intestinal outpatients in recent years.


### 2.2. Strain Isolation, Strain Identification, and Antimicrobial Susceptibility Testing

We isolated and identified bacteria using standard microbiological and biochemical methods. According to the clinical operation requirements of the National Clinical Inspection Operation Regulations (3rd Edition), various specimens were cultured and bacterial identification was performed using a Vitek 2 Company instrument and supporting identification cards with microbiological tubes. Extended-spectrumβ-lactamases (ESBLs)-producing Klebsiella pneumoniae (ESBLs-KPN), ESBLs-producing Escherichia coli (ESBLs-ECO), carbapenem-resistant (CRE) Klebsiella pneumoniae (CRE-KPN), CRE Escherichia coli (CRE-ECO), multidrug-resistant Acinetobacter baumannii (MDR-AB), multidrug-resistant Pseudomonas aeruginosa (MDR-PAE), and methicillin-resistant Staphylococcus aureus (MRSA) were defined based on their resistance to all antimicrobial agents as reported previously [6].In addition, instrument drug sensitivity cards and Kirby–Bauer agar diffusion methods were used to define antibiotic resistance. The results were interpreted according to the minimum inhibitory concentration (MIC) interpretive breakpoints recommended by the Clinical and Laboratory Standards Institute (CLSI) of 2016. The quality-control strains wereEscherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 700603, Acinetobacter baumannii ATCC 19606, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 13518, and Enterococcus faecium ATCC 29212.


### 2.3. Monitoring and Analysis of Multidrug-Resistant Bacteria

Our hospital microbiology laboratory uses special statistical software MDR for drug resistance analysis to conduct multidrug resistance analysis on the main pathogenic bacteria (Enterobacteriaceae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus). An interim standard definition of MDR, XDR, and PDR terms coauthored by experts from the United States, Israel, Greece, Switzerland, and Australia [6] was used to identify the drug resistance of the samples.


### 2.4. Statistical Analyses

Data from our study were analyzed with SPSS (version 22.0, IBM Corp., Armonk, NY) and Microsoft Excel software 2007 (Microsoft Corporation, Redmond, WA). Proportions were used to summarize categorical data as appropriate.


## 2.1. Source of Pathogenic Samples

Pathogen samples, including sputum, mid-section urine, blood, wound secretions, chest and gastric juices, bile, and puncture fluids, were taken from hospitalized patients from 2017 to 2019. To avoid overestimating antibiotic resistance, duplicate strains obtained from the same patient were deleted from the study. The study protocol was approved by the Ethics Committee of our hospital and given that medical records and patient information were anonymously reviewed and collected in this observational study, informed consent was not needed.In 2017, the total number of microbial culture samples submitted for inspection was 43,981, and the top five infection sites were the lower respiratory tract (271/28.65%), urinary tract (125/13.21%), upper respiratory tract (107/11.31%), eyes, ears, and oral cavities (67/7.08%), and blood (64/6.77%). Respiratory tract infection, however, has always represented the main site of infection.In 2018, the total number of microbial culture samples submitted for inspection was 42,923, a slight decrease from last year. The respiratory tract, urine, blood, stool, and female reproductive tract samples ranked in the top five, of which the respiratory tract samples, urine specimens, and blood specimens accounted for 43.93%, 12.35%, and 9.98% of the total, respectively. Stool specimens accounted for 6.73%, and female reproductive tract specimens accounted for 6.12%, a significant increase from last year by 4% and were related toStreptococcus agalactiae screening in obstetrics and gynecology.The total number of microbial culture specimens submitted for inspection in 2019 was 46,341, also representing an increase from last year. The lower respiratory tract, urine, and blood specimens ranked in the top three, accounting for 39.6%, 11.0%, and 8.8% of the total, respectively, and the female reproductive tract specimens accounted for 6.7%, an increase of 6.12% from 2018. The main reason is related toStreptococcus agalactiae screening in the obstetrics and gynecology department, and stool specimens accounted for 6.5% and were related to the decline in the number of intestinal outpatients in recent years.


## 2.2. Strain Isolation, Strain Identification, and Antimicrobial Susceptibility Testing

We isolated and identified bacteria using standard microbiological and biochemical methods. According to the clinical operation requirements of the National Clinical Inspection Operation Regulations (3rd Edition), various specimens were cultured and bacterial identification was performed using a Vitek 2 Company instrument and supporting identification cards with microbiological tubes. Extended-spectrumβ-lactamases (ESBLs)-producing Klebsiella pneumoniae (ESBLs-KPN), ESBLs-producing Escherichia coli (ESBLs-ECO), carbapenem-resistant (CRE) Klebsiella pneumoniae (CRE-KPN), CRE Escherichia coli (CRE-ECO), multidrug-resistant Acinetobacter baumannii (MDR-AB), multidrug-resistant Pseudomonas aeruginosa (MDR-PAE), and methicillin-resistant Staphylococcus aureus (MRSA) were defined based on their resistance to all antimicrobial agents as reported previously [6].In addition, instrument drug sensitivity cards and Kirby–Bauer agar diffusion methods were used to define antibiotic resistance. The results were interpreted according to the minimum inhibitory concentration (MIC) interpretive breakpoints recommended by the Clinical and Laboratory Standards Institute (CLSI) of 2016. The quality-control strains wereEscherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 700603, Acinetobacter baumannii ATCC 19606, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 13518, and Enterococcus faecium ATCC 29212.


## 2.3. Monitoring and Analysis of Multidrug-Resistant Bacteria

Our hospital microbiology laboratory uses special statistical software MDR for drug resistance analysis to conduct multidrug resistance analysis on the main pathogenic bacteria (Enterobacteriaceae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus). An interim standard definition of MDR, XDR, and PDR terms coauthored by experts from the United States, Israel, Greece, Switzerland, and Australia [6] was used to identify the drug resistance of the samples.


## 2.4. Statistical Analyses

Data from our study were analyzed with SPSS (version 22.0, IBM Corp., Armonk, NY) and Microsoft Excel software 2007 (Microsoft Corporation, Redmond, WA). Proportions were used to summarize categorical data as appropriate.


## 3. Results

### 3.1. Isolation of Pathogenic Bacteria

According to the results from the pathogen bacteria isolation from the three hospital departments from 2017 to 2019 (Table1), the top five pathogenic bacteria in three years were always Escherichia coli (12.8%), Staphylococcus aureus (11%), Klebsiella pneumoniae (10.8%), Pseudomonas aeruginosa (10.7%), and Acinetobacter baumannii (6.4%), which were relatively concentrated, and accounted for 51%, 53.4%, and 50.7% of the total cases each year. The average share of Enterococcus faecalis and Enterococcus faecium was 7.1% within three years.Table 1
The top 15 isolated pathogens in the three districts of the hospital in 2017, 2018, and 2019.
Year201720182019RankingsBacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportion (%)1Escherichia coli4560.131Escherichia coli4970.133Escherichia coli4650.1212Staphylococcus aureus3840.11Klebsiella pneumoniae4620.123Staphylococcus aureus4100.1073Pseudomonas aeruginosa3700.106Staphylococcus aureus4200.112Pseudomonas aeruginosa4090.1074Klebsiella pneumoniae3560.102Pseudomonas aeruginosa4060.108Klebsiella pneumoniae3820.15Acinetobacter baumannii2120.061Acinetobacter baumannii2190.058Acinetobacter baumannii2820.0736Enterococcus faecalis1560.045Staphylococcus epidermidis1760.047Staphylococcus epidermidis2510.0657Vibrio parahaemolyticus1350.039Enterococcus faecalis1470.039Enterococcus faecium1490.0398Staphylococcus epidermidis1290.037Enterococcus faecium1200.032Stenostomonas maltophilia1290.0349Stenostomonas maltophilia1030.03Streptococcus agalactiae1160.031Streptococcus agalactiae1230.03210Streptococcus agalactiae990.028Enterobacter cloacae1130.03Enterococcus faecalis1220.03211Enterobacter cloacae920.026Stenostomonas maltophilia870.023Enterobacter cloacae1010.02612Enterococcus faecium920.026Corynebacterium striatum840.022Haemophilus influenzae690.01813Corynebacterium striatum680.02Streptococcus pneumoniae680.018Corynebacterium striatum680.01814Streptococcus pneumoniae590.017Vibrio parahaemolyticus600.016Streptococcus pneumoniae640.01715Proteus mirabilis580.017Proteus mirabilis520.014Streptococcus astragali530.014Other bacteria7140.205Other bacteria7230.193Other bacteria7620.198Total34831Total37501Total38391From 2017 to 2019, the results of pathogenic bacterial isolation in the central intensive care unit (central ICU), respiratory intensive care unit (RICU), and emergency intensive care unit (EICU) were surveyed. Within the three ICU departments,Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii were always in the top eight within the three years. In central ICU, Pseudomonas aeruginosa was ranked first over three years and had the highest proportion between 15.4% and 17.3%, followed by Klebsiella pneumoniae (36/13.7%), and both showed an upward trend from 2017 to 2019. Acinetobacter baumannii (24 strains) and Escherichia coli (18 strains) came in third and fourth, with a proportion of 9.5% and 6.8%, respectively. Staphylococcus aureus (17/6.5%) and Enterococcus faecium (15/5.9%) also consistently ranked in the top eight for three years (Table 2). In RICUs, six pathogenic bacteria always ranked in the top eight. Pseudomonas aeruginosa (17/17.5%) had the largest average share over three years among the three ICU departments. The next was Klebsiella pneumoniae (14/14.8%), Escherichia coli (11/11%), Acinetobacter baumannii (7/7.7%), and Staphylococcus aureus (6/6.3%). In addition, Stenotrophomonas maltophilia (9 strains) accounted for 9.1%, and the average proportion was highest in the three ICU departments (Table 3). In EICUs, Acinetobacter baumannii (14/15.4%) had the highest average proportion from 2017 to 2019, followed by Klebsiella pneumoniae (14/14.7%), which ranked second for three consecutive years. Pseudomonas aeruginosa (13/13.7%), Escherichia coli (12/13.4%), Enterococcus faecium (8/8.1%), Staphylococcus aureus (7/7.1%), and Corynebacterium striatum (6/6.7%) are also consistently ranked in the top eight for three years and their average proportion was highest in the three ICU departments, respectively (Table 4).Table 2
Isolation of pathogenic bacteria in central intensive care units (central ICUs) in 2017, 2018, and 2019 years.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionPseudomonas aeruginosa400.154Pseudomonas aeruginosa480.160Pseudomonas aeruginosa390.173Klebsiella pneumoniae320.123Klebsiella pneumoniae410.137Klebsiella pneumoniae340.150Acinetobacter baumannii260.100Escherichia coli290.097Acinetobacter baumannii250.111Burkholderia cepacia190.073Acinetobacter baumannii220.073Staphylococcus aureus190.084Staphylococcus aureus160.062Enterococcus faecium170.057Burkholderia cepacia170.075Escherichia coli140.054Enterococcus faecalis160.053Stenostomonas maltophilia150.066Enterococcus faecium140.054Staphylococcus aureus150.050Enterococcus faecium150.066Enterobacter cloacae120.046Enterobacter cloacae140.047Escherichia coli120.053Enterococcus faecalis100.038Staphylococcus epidermidis140.047Enterobacter cloacae100.044Staphylococcus epidermidis80.031Burkholderia cepacia90.030Staphylococcus epidermidis80.035Stenostomonas maltophilia80.031Corynebacterium striatum90.030Streptococcus pneumoniae80.035Corynebacterium striatum80.031Stenostomonas maltophilia90.030Enterococcus faecalis80.035Streptococcus pneumoniae60.023Haemophilus influenzae70.023Corynebacterium striatum60.027Klebsiella aerogenes60.023Klebsiella aerogenes70.023Klebsiella aerogenes60.027Other bacteria410.158Other bacteria430.143Other bacteria40.018Total2601.000Total3001.000Total2261.000Table 3
Isolation of pathogenic bacteria in respiratory intensive care units (RICUs) in 2017, 2018, and 2019.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionEscherichia coli180.176Pseudomonas aeruginosa220.204Pseudomonas aeruginosa140.184Pseudomonas aeruginosa140.137Klebsiella pneumoniae170.157Klebsiella pneumoniae120.158Klebsiella pneumoniae130.127Stenostomonas maltophilia110.102Stenostomonas maltophilia70.092Stenostomonas maltophilia80.078Corynebacterium striatum90.083Acinetobacter baumannii60.079Acinetobacter baumannii80.078Acinetobacter baumannii80.074Escherichia coli60.079Staphylococcus aureus70.069Burkholderia cepacia80.074Staphylococcus aureus50.066Staphylococcus epidermidis70.069Escherichia coli80.074Burkholderia cepacia40.053Enterococcus faecalis60.059Staphylococcus aureus60.056Morganella morganii30.039Proteus mirabilis40.039Proteus mirabilis40.037Staphylococcus epidermidis30.039Enterobacter cloacae30.029Enterobacter cloacae20.019Proteus mirabilis30.039Streptococcus pneumoniae20.020Enterococcus faecalis20.019Staphylococcus hominis20.026Corynebacterium striatum20.020Enterococcus faecium20.019Corynebacterium striatum20.026Staphylococcus capitis20.020Streptococcus pneumoniae20.019Enterobacter cloacae20.026Enterococcus faecium10.010Staphylococcus capitis10.009Enterococcus faecalis20.026Other bacteria70.069Other bacteria60.056Other bacteria50.066Total1021.000Total1081.000Total760.704Table 4
Isolation of pathogenic bacteria in emergency intensive care units (EICUs) in 2017, 2018, and 2019.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionPseudomonas aeruginosa150.140Acinetobacter baumannii190.200Escherichia coli130.163Klebsiella pneumoniae130.121Klebsiella pneumoniae160.168Klebsiella pneumoniae120.150Acinetobacter baumannii120.112Pseudomonas aeruginosa150.158Acinetobacter baumannii120.150Escherichia coli120.112Escherichia coli120.126Pseudomonas aeruginosa90.113Enterococcus faecium100.093Enterococcus faecium60.063Enterococcus faecium70.088Staphylococcus aureus80.075Staphylococcus aureus60.063Staphylococcus aureus60.075Corynebacterium striatum80.075Corynebacterium striatum50.053Corynebacterium striatum60.075Stenostomonas maltophilia80.075Stenostomonas maltophilia40.042Stenostomonas maltophilia40.050Enterococcus faecalis60.056Proteus mirabilis30.032Enterococcus faecalis40.050Burkholderia cepacia40.037Burkholderia cepacia20.021Staphylococcus epidermidis20.025Proteus mirabilis20.019Enterococcus faecalis20.021Proteus mirabilis20.025Staphylococcus haemolyticus10.009Staphylococcus haemolyticus10.011Staphylococcus haemolyticus10.013Corynebacterium afermentans10.009Corynebacterium urealyticum10.011Staphylococcus capitis10.013Staphylococcus capitis10.009Enterobacter avium10.011Saprophytic staphylococcus10.013Other bacteria60.056Other bacteria20.021Other bacteria00.000Total1071.000Total951.000Total801.000


### 3.2. Distribution of Isolated Strains from Blood, Urine, and Sputum Samples

The composition of isolates from different sources from 2017 to 2019 was analyzed, and the results are shown in Tables5–7. From 2017 to 2019, the average proportion of Escherichia coli isolates (61/22.8%) in blood samples was the highest, showing a downward trend. At the same time, Staphylococcus epidermidis (48/18.1%) and Klebsiella pneumoniae (32/12%) occupied the second and third places in each of the three years. The mean proportion of Staphylococcus epidermidis in blood specimens was higher than that seen in urine within the three years, but it was not found in sputum specimens. The composition of blood samples in 2017 and 2019 ranked fourth and Acinetobacter baumannii accounted for about 6.7%, but Staphylococcus hominis ranked fourth in 2018, accounting for 7.5%, Staphylococcus hominis ranked fifth for the three years, accounting for 8.1%, and was unique to blood samples (Table 5).Table 5
Composition of blood specimen isolates in 2017, 2018, and 2019 years.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionEscherichia coli620.238Escherichia coli700.228Escherichia coli500.218Staphylococcus epidermidis450.173Staphylococcus epidermidis570.186Staphylococcus epidermidis420.183Klebsiella pneumoniae300.115Klebsiella pneumoniae420.137Klebsiella pneumoniae250.109Acinetobacter baumannii200.077Staphylococcus hominis230.075Acinetobacter baumannii130.057Pseudomonas aeruginosa120.046Staphylococcus aureus130.042Staphylococcus hominis110.048Staphylococcus aureus110.042Enterococcus faecalis120.039Enterococcus faecium100.044Staphylococcus hominis100.038Acinetobacter baumannii110.036Staphylococcus aureus90.039Enterobacter cloacae90.035Pseudomonas aeruginosa70.023Staphylococcus haemolyticus90.039Enterococcus faecium80.031Enterobacter cloacae60.020Pseudomonas aeruginosa70.031Staphylococcus haemolyticus40.015Enterococcus faecium40.013Burkholderia cepacia30.013Other bacteria490.188Other bacteria620.202Other bacteria500.218Total2601.000Total3071.000Total2291.000Table 6
Composition of urine specimen isolates in 2017, 2018, and 2019.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionEscherichia coli2580.422Escherichia coli2620.393Escherichia coli2650.377Klebsiella pneumoniae750.123Enterococcus faecium690.103Enterococcus faecium860.123Enterococcus faecium700.114Enterococcus faecalis630.094Enterococcus faecalis590.084Enterococcus faecalis630.103Klebsiella pneumoniae510.076Klebsiella pneumoniae510.073Pseudomonas aeruginosa340.056Pseudomonas aeruginosa340.051Pseudomonas aeruginosa340.048Staphylococcus epidermidis220.036Staphylococcus epidermidis210.031Staphylococcus epidermidis280.040Proteus mirabilis170.028Proteus mirabilis180.027Streptococcus agalactiae180.026Enterobacter cloacae150.025Streptococcus agalactiae160.024Proteus mirabilis150.021Streptococcus agalactiae140.023Morganella morganii120.018Acinetobacter haemolyticus140.020Acinetobacter haemolyticus110.018Corynebacterium glutamicum110.016Enterobacter cloacae120.017Other bacteria330.054Other bacteria1100.165Other bacteria1200.171Total6121.000Total6671.000Total7021.000Table 7
Composition of sputum specimen isolates in 2017, 2018, and 2019.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionPseudomonas aeruginosa2800.233Klebsiella pneumoniae2860.224Pseudomonas aeruginosa2950.220Klebsiella pneumoniae2620.218Pseudomonas aeruginosa2820.221Acinetobacter baumannii2470.185Acinetobacter baumannii2030.169Acinetobacter baumannii1830.143Klebsiella pneumoniae2340.175Staphylococcus aureus1000.083Staphylococcus aureus1100.086Staphylococcus aureus1080.081Escherichia coli850.071Stenostomonas maltophilia710.056Stenostomonas maltophilia1030.077Stenostomonas maltophilia620.052Escherichia coli600.047Escherichia coli590.044Corynebacterium striatum480.040Corynebacterium striatum500.039Enterobacter cloacae520.039Enterobacter cloacae410.034Enterobacter cloacae480.038Corynebacterium striatum420.031Streptococcus pneumoniae360.030Streptococcus pneumoniae330.026Haemophilus influenzae400.030Burkholderia cepacia290.024Burkholderia cepacia310.024Burkholderia cepacia300.022Other bacteria540.045Other bacteria1230.096Other bacteria1280.096Total12001.000Total12771.000Total13381.000It was found thatEscherichia coli (39.7%), Enterococcus faecium (11.3%), Enterococcus faecalis (9.4%), and Klebsiella pneumoniae (9.1%) ranked in the top four pathogenic bacteria from urine sample isolates. The most predominant pathogen in the urine samples was Escherichia coli accounting for 42.2%, 39.3%, and 37.8% from 2017 to 2019. Within the three years, compared to the blood and sputum samples, Escherichia coli accounted for the highest proportion of the urine samples isolated strains. Enterococcus faecium and Enterococcus faecalis have a higher proportion in urine than in blood samples, and they were not present in samples (Table 6).Pseudomonas aeruginosa (22.5%), Klebsiella pneumoniae (20.6%), and Acinetobacter baumannii (16.6%) were the top three in sputum sample isolated strains. Staphylococcus aureus (8.3%) and Stenotrophomonas maltophilia (6.1%) were also common in sputum specimens and ranked fourth and fifth. Moreover, Stenotrophomonas maltophilia is a pathogen specific to sputum samples, and its proportion was increasing from 5.2% to 7.7% during 2017 to 2019 (Table 7).


### 3.3. Antibiotic Resistance Analysis

Combining the isolation of the pathogenic bacteria from the three hospital departments from 2017 to 2019 and the distribution of isolated strains from blood, urine and sputum specimens, it can be seen that the bacteria that are susceptible and have a high titer in each specimen were mainlyEscherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter baumannii and their antibiotic resistance was found to be unchanged.From 2017 to 2019,Escherichia coli was generally resistant to trimethoprim and minocycline, with a resistance rate of up to 100% and with high sensitivity to imipenem, amikacin, ertapenem, and other drugs (Table 8). The resistance rate of Klebsiella pneumoniae to trimethoprim, cefuroxime, piperacillin, piperacillin-sulbactam, and ampicillin was higher than 90%. However, its resistance to cefoperazone-sulbactam, ertapenem, and amikacin was lower than 40% (Table 9). The resistance of Pseudomonas aeruginosa to most antibiotics such as piperacillin, ciprofloxacin, amikacin, and tobramycin was less than 30%, and resistance to polymyxin B was less than 5%, and even reached a sensitivity of 100% in 2018 and 2019 (Table 10). Acinetobacter baumannii had high sensitivity to tigecycline and minocycline of less than 30%, and the resistance rate to tigecycline was zero but was greater than 60% resistant to many drugs such as piperacillin, ceftazidime, gentamicin, and imipenem (Table 11). Staphylococcus aureus had the highest resistance rate to penicillin, at more than 80%, and the resistance rate to erythromycin was approximately 60%. However, no strains were resistant to antibiotics such as vancomycin, teicoplanin, tigecycline, and linezolid (Table 12).Table 8
Drug resistance rates ofEscherichia coli from 2017 to 2019.
201720182019Escherichia coliDrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Trimethoprim100Ampicillin-sulbactam71.3Ampicillin-sulbactam76.8Minocycline100Ciprofloxacin60.4Cefuroxime54.3Cefazolin90.27Levofloxacin55.9Ciprofloxacin54.1Ampicillin87.7Ceftriaxone55.2Levofloxacin49.9Ceftriaxone78Cotrimoxazole49.5Ceftriaxone48.3Ciprofloxacin78Gentamicin39.6Cotrimoxazole45.3Levofloxacin73.2Aztreonam36.5Gentamicin34.9Ampicillin-sulbactam65.9Ceftazidime26.4Aztreonam27.9Compound sulfadiazine64Cefepime23.3Ceftazidime20.3Aztreonam55.2Tobramycin14.3Cefepime17.4Piperacillin50Cefoperazone-sulbactam7.9Tobramycin10.5Tobramycin49.2Fosfomycin7Fosfomycin7.0Cefepime36.4Ertapenem5.2Cefoperazone-sulbactam3.4Gentamicin36.3Piperacillin-tazobactam4.6Nitrofurantoin2.5Cefotaxime32.4Imipenem4Piperacillin-tazobactam2.4Ceftazidime32Nitrofurantoin2.9Amikacin1.7Amikacin1.4Ertapenem0.7Imipenem0.6Table 9
Drug resistance rates ofKlebsiella pneumoniae from 2017 to 2019.
201720182019DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Klebsiella pneumoniaeTrimethoprim100Ampicillin-sulbactam71.7Ampicillin-sulbactam66.7Cefuroxime100Nitrofurantoin34.8Nitrofurantoin33.9Piperacillin100Fosfomycin34.1Cotrimoxazole29.6Piperacillin-sulbactam100Ceftriaxone30Aztreonam26.7Ampicillin96.3Cotrimoxazole27Cotrimoxazole23.8Cefazolin81.7Levofloxacin25.6Ciprofloxacin22.2Nitrofurantoin78.8Aztreonam25.2Ceftazidime20.9Fosfomycin72.5Ciprofloxacin25.1Levofloxacin19.9Ampicillin-sulbactam70.8Ceftazidime23.9Gentamicin18.9Ceftriaxone65.7Gentamicin22.7Cefepime17.1Cefepime53.5Cefepime22.2Tobramycin13.5Tobramycin52.6Tobramycin19Imipenem11.8Aztreonam51.3Cefoperazone-sulbactam18.9Piperacillin-tazobactam11.3Compound sulfadiazine50.8Imipenem17.8Cefoperazone-sulbactam11.1Ceftazidime50Ertapenem17.3Ertapenem8.8Cefotaxime50Piperacillin-tazobactam17Amikacin6.0Ciprofloxacin49.2Amikacin12.2Tigecycline0.0Cefoperazone48.6Levofloxacin47.2Gentamicin46.1Piperacillin-tazobactam44.3Imipenem40.2Cefoperazone-sulbactam32.4Table 10
Drug resistance rates ofPseudomonas aeruginosa from 2017 to 2019.
201720182019DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Pseudomonas aeruginosaAztreonam37.2Meropenem22Meropenem18.4Cefepime34Aztreonam18.8Imipenem15.8Imipenem33.5Levofloxacin18.8Levofloxacin13.7Piperacillin29.1Cefepime18.7Aztreonam13.4Meropenem27.1Imipenem18.2Gentamicin12.2Gentamicin25.2Gentamicin15.6Cefepime12.1Piperacillin-sulbactam25.1Ciprofloxacin13.5Piperacillin11.6Ceftazidime23.7Piperacillin12.8Cefoperazone-sulbactam9.2Levofloxacin20Ceftazidime12.2Ciprofloxacin8.6Ciprofloxacin18.4Cefoperazone-sulbactam11.1Tobramycin7.7Tobramycin13.5Tobramycin9.9Piperacillin-tazobactam7.2Amikacin10Amikacin9.2Ceftazidime6.8Polymyxin B2.5Piperacillin-tazobactam8.6Amikacin3.5Polymyxin B0Polymyxin B0.0Table 11
Drug resistance rates ofAcinetobacter baumannii from 2017 to 2019.
201720182019DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Acinetobacter baumanniiPiperacillin73.5Piperacillin63Piperacillin73.2Moxifloxacin74.7Moxifloxacin63.8Imipenem72.2Cefepime73.6Cefepime63.7Piperacillin-tazobactam71.2Piperacillin-tazobactam74.6Piperacillin-tazobactam63.6Cefepime70.0Ceftazidime73.9Ceftazidime63.6Ceftazidime69.8Imipenem73.1Imipenem62.7Gentamicin69.6Levofloxacin72.5Levofloxacin62.6Ciprofloxacin67.7Gentamicin69.7Gentamicin60.6Levofloxacin61.5Amikacin66.5Amikacin58.1Tobramycin55.4Tobramycin65.3Tobramycin57.2Amikacin42.2Cefoperazone-sulbactam37.3Cefoperazone-sulbactam32.9Minocycline27.3Minocycline25.6Minocycline21.5Tigecycline0.0Tigecycline0Tigecycline0Table 12
Drug resistance rates ofStaphylococcus aureus from 2017 to 2019.
201720182019DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Staphylococcus aureusPenicillin91.3Penicillin87.6Penicillin89.6Erythromycin61.8Erythromycin59.8Erythromycin62.7Clindamycin58.6Clindamycin57.1Clindamycin58.4Oxacillin35.2Oxacillin32.3Oxacillin36.8Tetracycline24.2Tetracycline23.2Cotrimoxazole24.1Cotrimoxazole17.3Cotrimoxazole16.3Tetracycline18.3Ciprofloxacin16.5Ciprofloxacin15Ciprofloxacin18.0Gentamicin14.8Gentamicin14Moxifloxacin15.7Moxifloxacin14Moxifloxacin13.3Levofloxacin14.2Levofloxacin13Levofloxacin10Gentamicin14.1Rifampicin3.5Rifampicin3.3Rifampicin3.7Nitrofurantoin1.2Nitrofurantoin0.8Nitrofurantoin0.8Linezolid0Linezolid0Linezolid0.0Vancomycin0Vancomycin0Vancomycin0.0Teicoplanin0Teicoplanin0Teicoplanin0.0Tigecycline0Tigecycline0Tigecycline0.0


### 3.4. Multidrug Resistance Analysis

Analysis of multiple drug resistance for the main pathogenic bacteria in our hospital in 2017 is shown in Figure1. In 2017, a total of 1181 multidrug-resistant bacterial strains of Enterobacteriaceae were isolated, accounting for the largest proportion of the detected multidrug-resistant strains; of which 491 strains of multidrug-resistant organisms (MDRO) accounted for 41.6%, and no XDR and PDR strains were found (Figure 1(a)). ESBLs-KPN is highly resistant to amoxicillin and ceftriaxone, with resistance rates of 100% and 99.4%, respectively, and the sensitivity to ertapenem, imipenem, and piperacillin/tazobactam was above 95% (Table 13). The resistance rate of CRE-KPN to all drugs was above 50%, among which ampicillin, cefoperazone-sulbactam, ampicillin-sulbactam, ceftazidime, and ceftriaxone were all resistant by 100%. The resistance rates to nitrofurantoin, ciprofloxacin, levofloxacin, aztreonam, and cefepime were all greater than 95% (Table 14) and the resistance rates of ESBLs-producing Escherichia coli (ESBLs-ECO) to ampicillin and ceftriaxone were over 99%, and sensitivities to drugs such as amikacin, nitrofurantoin, and cefepime were all greater than 60%, with no strains being resistant to ertapenem, piperacillin-tazobactam, or imipenem (Table 15). A total of 263 strains of Acinetobacter were isolated, including 150 strains of MDRO, accounting for 57%, and no XDR and PDR strains were found (Figure 1(b)). The resistance rate of MDR-Acinetobacter baumannii (MDR-AB) to levofloxacin, moxifloxacin, and ampicillin was up to 100%, and the drug resistance to cotrimoxazole, amikacin, and other drugs was also more than 70% (Table 16). Of the 395 strains of Pseudomonas aeruginosa isolated, 90 strains of MDRO accounted for 22.8%, and 21 strains of XDR accounted for 5.3%. No PDR strain was found (Figure 1(c)). MDR-Pseudomonas aeruginosa (MDR-PAE) showed more than 97% resistance to ciprofloxacin, piperacillin, and amtronam, among which the resistance rate for ceftazidime, imipenem, and levofloxacin was 100%. While sensitivity to polymyxin B and tobramycin had a sensitivity of 98.7% (Table 17). A total of 732 strains of Staphylococcus were isolated, of which 316 were MDRO strains, accounting for 43.2%, and no XDR and PDR strains were found (Figure 1(d)). Methicillin-resistant Staphylococcus aureus (MRSA) was 100% resistant to benzacillin, 60% resistant to erythromycin, 50% resistant to ciprofloxacin, clindamycin, and tetracycline, but 100% sensitive to linezolid and vancomycin (Table 18).Figure 1
Analysis of multiple drug resistance for the main pathogenic bacteria in our hospital in 2017. (a) The analysis of multiple drug resistance ofEnterobacteriaceae bacteria. (b) The analysis of multiple drug resistance of Acinetobacter bacteria. (c) The analysis of multiple drug resistance of Pseudomonas aeruginosa. (d) The analysis of multiple drug resistance of Staphylococcus bacteria.
(a)(b)(c)(d)Table 13
Analysis of multiple drug resistance rate of ESBLs-KPN in 2017.
DrugsDrug resistance rate (%)ESBLs-KPNErtapenem1.8Imipenem2.8Piperacillin-tazobactam8Amikacin9.7Cefoperazone-sulbactam21.7Tobramycin27.8Gentamicin40.9Fosfomycin42.3Nitrofurantoin48.3Levofloxacin49.4Cefepime50Ciprofloxacin60.8Ceftazidime63.1Aztreonam73.9Cotrimoxazole80.7Ampicillin-sulbactam90.3Ceftriaxone99.4Ampicillin100Table 14
Analysis of multiple drug resistance rates of CRE-KPN in 2017.
DrugsDrug resistance rate (%)CRE-KPNCotrimoxazole52.7Fosfomycin60Amikacin72.8Tobramycin79Gentamicin82.1Nitrofurantoin96.3Ciprofloxacin98.3Levofloxacin98.3Aztreonam98.6Cefepime98.9Piperacillin-tazobactam99.4Ampicillin100Cefoperazone-sulbactam100Ampicillin-sulbactam100Ceftazidime100Ceftriaxone100Ertapenem100Imipenem100Table 15
Analysis of multiple drug resistance rate of ESBLs-ECO in 2017.
DrugsDrug resistance rate (%)ESBLs-ECOErtapenem0Piperacillin-tazobactam0Imipenem0ASmikacin2.2Nitrofurantoin3Cefoperazone-sulbactam6.4Fosfomycin12.3Tobramycin17.5Cefepime32.9Gentamicin41.1Ceftazidime43.4Cotrimoxazole53.9Aztreonam66.3Ampicillin-sulbactam66.8Levofloxacin71.6Ciprofloxacin75.8Ampicillin99.3Ceftriaxone99.5Table 16
Analysis of multiple drug resistance rate of MDR-AB in 2017.
DrugsDrug resistance rate (%)MDR-ABCotrimoxazole74.7Amikacin78.1Tobramycin81.1Gentamicin82.2Minocycline84.3Ampicillin100Piperacillin100Piperacillin-tazobactam100Ceftazidime100Ceftriaxone100Cefotaxime100Cefepime100Aztreonam100Table 17
Analysis of multiple drug resistance rate of MDR-PAE in 2017.
DrugsDrug resistance rate (%)MDR-PAEPolymyxin B1.3Tobramycin19.4Amikacin46.6Gentamicin69.2Cefoperazone-sulbactam81Piperacillin/tazobactam93.3Ciprofloxacin97.7Piperacillin99.3Aztreonam99.3Cefepime99.7Ceftazidime100Imipenem100Levofloxacin100Table 18
Analysis of multiple drug resistance rate of MRSA in 2017.
DrugsDrugresistance rate (%)MRSALinezolid0Vancomycin0Nitrofurantoin4.5Cotrimoxazole10Rifampicin28.9Gentamicin39.1Levofloxacin46.9Moxifloxacin48.6Ciprofloxacin51.1Clindamycin51.7Tetracycline52.5Erythromycin61.1Oxacillin100In 2018, a total of 1293 strains of multidrug-resistant bacteria such asEnterobacteriaceae were isolated, of which MDRO (574 strains) accounted for 44.4%, while XDR and PDR strains were not found (Figure 2(a)). A total of 270 strains of Acinetobacter were isolated, including 145 strains of MDRO, accounting for 53.7%, and no XDR and PDR strains were found (Figure 2(b)). A total of 406 strains of Pseudomonas aeruginosa were isolated, among which 107 strains of MDRO accounted for 26.4%, while 26 strains of XDR accounted for 6.4%, and no PDR strains were found (Figure 2(c)). A total of 704 strains of Staphylococcus bacteria were isolated, including 300 strains (42.6%) of MDRO, with no XDR and PDR strains being found (Figure 2(d)). The resistance rates of MRSA to benzacillin and penicillin were 100% and 99.2%, respectively. No strains were found to be resistant to linezolid, vancomycin, teicoplanin, and tigecycline (Table 19).Figure 2
Analysis of multiple drug resistance for the main pathogenic bacteria in our hospital in 2018. (a) The analysis of multiple drug resistance ofEnterobacteriaceae bacteria. (b) The analysis of multiple drug resistance of Acinetobacter bacteria. (c) The analysis of multiple drug resistance of Pseudomonas aeruginosa. (d) The analysis of multiple drug resistance of Staphylococcus bacteria.
(a)(b)(c)(d)Table 19
Analysis of multiple drug resistance rate of MRSA in 2018.
DrugsDrug resistance rate (%)MRSAPenicillin100Oxacillin100Erythromycin74.3Clindamycin69.1Tetracycline38.4Ciprofloxacin31.8Moxifloxacin30.3Levofloxacin28.3Cotrimoxazole23.8Gentamicin20.5Rifampicin9.9Nitrofurantoin1.3Linezolid0Vancomycin0Teicoplanin0Tigecycline0As shown in Figure3(a), in 2019, a total of 1166 strains of Enterobacteriaceae were isolated, of which 484 strains were isolated by MDR, accounting for 41.5%, and no XDR and PDR strains were found. The high resistance of ESBLs-producing Enterobacteriaceae to ceftriaxone and amcarcillin-sulbactam was observed, both more than 95%. Its drug resistance to cephalosporin, tobramycin, and furantoin was less than 40%, among which the drug resistance rate for tigecycline, imipenem, and amikacin was less than 5% (Table 20). Carbapenem-resistant (CRE) Enterobacteriaceae bacteria showed the highest resistance to amcarcillin-sulbactam (97.1%), and the resistance rate to most drugs ranged from 70% to 90%, but they were sensitive to tigecycline and amikacin (Table 21). A total of 325 strains of Acinetobacter were isolated, of which 213 strains were isolated from MDR, accounting for 65.5%, and no XDR and PDR strains were found (Figure 3(b)). A total of 409 strains of Pseudomonas aeruginosa were isolated, of which 86 strains were isolated by MDR, accounting for 21.0%, and 23 strains were isolated by XDR, accounting for 5.6%, with no PDR strain being found (Figure 3(c)). A total of 768 strains of Staphylococcus were isolated, of which 356 strains were isolated by MDRO, accounting for 46.4%, and no XDR and PDR strains were found (Figure 3(d)). Similar to 2018, MRSA showed 100% resistance to penicillin and benzacillin, and the sensitivity to tetracycline, ciprofloxacin, and other drugs was more than 60%, and no strains resistant to linezolid, vancomycin, and other four drugs were found (Table 22).Figure 3
Analysis of multiple drug resistance for the main pathogenic bacteria in our hospital in 2019. (a) The analysis of multiple drug resistance ofEnterobacteriaceae bacteria. (b) The analysis of multiple drug resistance of Acinetobacter bacteria. (c) The analysis of multiple drug resistance of Pseudomonas aeruginosa. (d) The analysis of multiple drug resistance of Staphylococcus bacteria.
(a)(b)(c)(d)Table 20
Analysis of multiple drug resistance rate of ESBLs in 2019.
DrugsDrug resistance rate (%)ESBLsCeftriaxone96.7Ampicillin-sulbactam96.5Ciprofloxacin67.2Aztreonam64.7Levofloxacin61.3Cotrimoxazole56.2Ceftazidime44.0Gentamicin43.1Cefepime36.2Tobramycin21.5Nitrofurantoin14.2Fosfomycin13.6Cefoperazone-sulbactam8.2Piperacillin-tazobactam4.0Ertapenem3.0Amikacin2.7Imipenem1.0Table 21
Analysis of multiple drug resistance rate of CREs in 2019.
DrugsDrug resistance rate (%)CREsAmpicillin-sulbactam97.1Imipenem88.9Ceftriaxone84.9Ertapenem83.6Ceftazidime82.7Nitrofurantoin79.4Ciprofloxacin78.9Aztreonam77.3Levofloxacin76.8Cefepime75.8Piperacillin-tazobactam74.5Cefoperazone-sulbactam70.4Gentamicin53.5Tobramycin50.0Cotrimoxazole43.3Amikacin31.6Tigecycline0.0Table 22
Analysis of multiple drug resistance rate of MRSA in 2019.
DrugsDrug resistance rate (%)MRSAOxacillin100Penicillin99.2Erythromycin79.5Clindamycin76.5Tetracycline51.6Ciprofloxacin31.5Moxifloxacin29.5Levofloxacin28.2Gentamicin20.3Rifampicin10.6Cotrimoxazole6.1Nitrofurantoin2.3Linezolid0Vancomycin0Teicoplanin0Tigecycline0


### 3.5. The Trend of Isolate Major Multidrug-Resistant Bacteria in Our Hospital in the Past Four Years

As shown in Figure4, the isolation rate of MDR-AB, which remained at the top for three years, declined in 2018 but increased again in 2019. ESBLs-ranked second in the three-year average separation rate, while MDR-PAB showed a continuous downward trend, whereas MRSA was the opposite, with a continuous increase being observed and CRE also exhibited a rise.Figure 4
The trend of separation rate (%) of main multidrug-resistant strains in our hospital in recent four years.


## 3.1. Isolation of Pathogenic Bacteria

According to the results from the pathogen bacteria isolation from the three hospital departments from 2017 to 2019 (Table1), the top five pathogenic bacteria in three years were always Escherichia coli (12.8%), Staphylococcus aureus (11%), Klebsiella pneumoniae (10.8%), Pseudomonas aeruginosa (10.7%), and Acinetobacter baumannii (6.4%), which were relatively concentrated, and accounted for 51%, 53.4%, and 50.7% of the total cases each year. The average share of Enterococcus faecalis and Enterococcus faecium was 7.1% within three years.Table 1
The top 15 isolated pathogens in the three districts of the hospital in 2017, 2018, and 2019.
Year201720182019RankingsBacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportion (%)1Escherichia coli4560.131Escherichia coli4970.133Escherichia coli4650.1212Staphylococcus aureus3840.11Klebsiella pneumoniae4620.123Staphylococcus aureus4100.1073Pseudomonas aeruginosa3700.106Staphylococcus aureus4200.112Pseudomonas aeruginosa4090.1074Klebsiella pneumoniae3560.102Pseudomonas aeruginosa4060.108Klebsiella pneumoniae3820.15Acinetobacter baumannii2120.061Acinetobacter baumannii2190.058Acinetobacter baumannii2820.0736Enterococcus faecalis1560.045Staphylococcus epidermidis1760.047Staphylococcus epidermidis2510.0657Vibrio parahaemolyticus1350.039Enterococcus faecalis1470.039Enterococcus faecium1490.0398Staphylococcus epidermidis1290.037Enterococcus faecium1200.032Stenostomonas maltophilia1290.0349Stenostomonas maltophilia1030.03Streptococcus agalactiae1160.031Streptococcus agalactiae1230.03210Streptococcus agalactiae990.028Enterobacter cloacae1130.03Enterococcus faecalis1220.03211Enterobacter cloacae920.026Stenostomonas maltophilia870.023Enterobacter cloacae1010.02612Enterococcus faecium920.026Corynebacterium striatum840.022Haemophilus influenzae690.01813Corynebacterium striatum680.02Streptococcus pneumoniae680.018Corynebacterium striatum680.01814Streptococcus pneumoniae590.017Vibrio parahaemolyticus600.016Streptococcus pneumoniae640.01715Proteus mirabilis580.017Proteus mirabilis520.014Streptococcus astragali530.014Other bacteria7140.205Other bacteria7230.193Other bacteria7620.198Total34831Total37501Total38391From 2017 to 2019, the results of pathogenic bacterial isolation in the central intensive care unit (central ICU), respiratory intensive care unit (RICU), and emergency intensive care unit (EICU) were surveyed. Within the three ICU departments,Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii were always in the top eight within the three years. In central ICU, Pseudomonas aeruginosa was ranked first over three years and had the highest proportion between 15.4% and 17.3%, followed by Klebsiella pneumoniae (36/13.7%), and both showed an upward trend from 2017 to 2019. Acinetobacter baumannii (24 strains) and Escherichia coli (18 strains) came in third and fourth, with a proportion of 9.5% and 6.8%, respectively. Staphylococcus aureus (17/6.5%) and Enterococcus faecium (15/5.9%) also consistently ranked in the top eight for three years (Table 2). In RICUs, six pathogenic bacteria always ranked in the top eight. Pseudomonas aeruginosa (17/17.5%) had the largest average share over three years among the three ICU departments. The next was Klebsiella pneumoniae (14/14.8%), Escherichia coli (11/11%), Acinetobacter baumannii (7/7.7%), and Staphylococcus aureus (6/6.3%). In addition, Stenotrophomonas maltophilia (9 strains) accounted for 9.1%, and the average proportion was highest in the three ICU departments (Table 3). In EICUs, Acinetobacter baumannii (14/15.4%) had the highest average proportion from 2017 to 2019, followed by Klebsiella pneumoniae (14/14.7%), which ranked second for three consecutive years. Pseudomonas aeruginosa (13/13.7%), Escherichia coli (12/13.4%), Enterococcus faecium (8/8.1%), Staphylococcus aureus (7/7.1%), and Corynebacterium striatum (6/6.7%) are also consistently ranked in the top eight for three years and their average proportion was highest in the three ICU departments, respectively (Table 4).Table 2
Isolation of pathogenic bacteria in central intensive care units (central ICUs) in 2017, 2018, and 2019 years.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionPseudomonas aeruginosa400.154Pseudomonas aeruginosa480.160Pseudomonas aeruginosa390.173Klebsiella pneumoniae320.123Klebsiella pneumoniae410.137Klebsiella pneumoniae340.150Acinetobacter baumannii260.100Escherichia coli290.097Acinetobacter baumannii250.111Burkholderia cepacia190.073Acinetobacter baumannii220.073Staphylococcus aureus190.084Staphylococcus aureus160.062Enterococcus faecium170.057Burkholderia cepacia170.075Escherichia coli140.054Enterococcus faecalis160.053Stenostomonas maltophilia150.066Enterococcus faecium140.054Staphylococcus aureus150.050Enterococcus faecium150.066Enterobacter cloacae120.046Enterobacter cloacae140.047Escherichia coli120.053Enterococcus faecalis100.038Staphylococcus epidermidis140.047Enterobacter cloacae100.044Staphylococcus epidermidis80.031Burkholderia cepacia90.030Staphylococcus epidermidis80.035Stenostomonas maltophilia80.031Corynebacterium striatum90.030Streptococcus pneumoniae80.035Corynebacterium striatum80.031Stenostomonas maltophilia90.030Enterococcus faecalis80.035Streptococcus pneumoniae60.023Haemophilus influenzae70.023Corynebacterium striatum60.027Klebsiella aerogenes60.023Klebsiella aerogenes70.023Klebsiella aerogenes60.027Other bacteria410.158Other bacteria430.143Other bacteria40.018Total2601.000Total3001.000Total2261.000Table 3
Isolation of pathogenic bacteria in respiratory intensive care units (RICUs) in 2017, 2018, and 2019.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionEscherichia coli180.176Pseudomonas aeruginosa220.204Pseudomonas aeruginosa140.184Pseudomonas aeruginosa140.137Klebsiella pneumoniae170.157Klebsiella pneumoniae120.158Klebsiella pneumoniae130.127Stenostomonas maltophilia110.102Stenostomonas maltophilia70.092Stenostomonas maltophilia80.078Corynebacterium striatum90.083Acinetobacter baumannii60.079Acinetobacter baumannii80.078Acinetobacter baumannii80.074Escherichia coli60.079Staphylococcus aureus70.069Burkholderia cepacia80.074Staphylococcus aureus50.066Staphylococcus epidermidis70.069Escherichia coli80.074Burkholderia cepacia40.053Enterococcus faecalis60.059Staphylococcus aureus60.056Morganella morganii30.039Proteus mirabilis40.039Proteus mirabilis40.037Staphylococcus epidermidis30.039Enterobacter cloacae30.029Enterobacter cloacae20.019Proteus mirabilis30.039Streptococcus pneumoniae20.020Enterococcus faecalis20.019Staphylococcus hominis20.026Corynebacterium striatum20.020Enterococcus faecium20.019Corynebacterium striatum20.026Staphylococcus capitis20.020Streptococcus pneumoniae20.019Enterobacter cloacae20.026Enterococcus faecium10.010Staphylococcus capitis10.009Enterococcus faecalis20.026Other bacteria70.069Other bacteria60.056Other bacteria50.066Total1021.000Total1081.000Total760.704Table 4
Isolation of pathogenic bacteria in emergency intensive care units (EICUs) in 2017, 2018, and 2019.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionPseudomonas aeruginosa150.140Acinetobacter baumannii190.200Escherichia coli130.163Klebsiella pneumoniae130.121Klebsiella pneumoniae160.168Klebsiella pneumoniae120.150Acinetobacter baumannii120.112Pseudomonas aeruginosa150.158Acinetobacter baumannii120.150Escherichia coli120.112Escherichia coli120.126Pseudomonas aeruginosa90.113Enterococcus faecium100.093Enterococcus faecium60.063Enterococcus faecium70.088Staphylococcus aureus80.075Staphylococcus aureus60.063Staphylococcus aureus60.075Corynebacterium striatum80.075Corynebacterium striatum50.053Corynebacterium striatum60.075Stenostomonas maltophilia80.075Stenostomonas maltophilia40.042Stenostomonas maltophilia40.050Enterococcus faecalis60.056Proteus mirabilis30.032Enterococcus faecalis40.050Burkholderia cepacia40.037Burkholderia cepacia20.021Staphylococcus epidermidis20.025Proteus mirabilis20.019Enterococcus faecalis20.021Proteus mirabilis20.025Staphylococcus haemolyticus10.009Staphylococcus haemolyticus10.011Staphylococcus haemolyticus10.013Corynebacterium afermentans10.009Corynebacterium urealyticum10.011Staphylococcus capitis10.013Staphylococcus capitis10.009Enterobacter avium10.011Saprophytic staphylococcus10.013Other bacteria60.056Other bacteria20.021Other bacteria00.000Total1071.000Total951.000Total801.000


## 3.2. Distribution of Isolated Strains from Blood, Urine, and Sputum Samples

The composition of isolates from different sources from 2017 to 2019 was analyzed, and the results are shown in Tables5–7. From 2017 to 2019, the average proportion of Escherichia coli isolates (61/22.8%) in blood samples was the highest, showing a downward trend. At the same time, Staphylococcus epidermidis (48/18.1%) and Klebsiella pneumoniae (32/12%) occupied the second and third places in each of the three years. The mean proportion of Staphylococcus epidermidis in blood specimens was higher than that seen in urine within the three years, but it was not found in sputum specimens. The composition of blood samples in 2017 and 2019 ranked fourth and Acinetobacter baumannii accounted for about 6.7%, but Staphylococcus hominis ranked fourth in 2018, accounting for 7.5%, Staphylococcus hominis ranked fifth for the three years, accounting for 8.1%, and was unique to blood samples (Table 5).Table 5
Composition of blood specimen isolates in 2017, 2018, and 2019 years.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionEscherichia coli620.238Escherichia coli700.228Escherichia coli500.218Staphylococcus epidermidis450.173Staphylococcus epidermidis570.186Staphylococcus epidermidis420.183Klebsiella pneumoniae300.115Klebsiella pneumoniae420.137Klebsiella pneumoniae250.109Acinetobacter baumannii200.077Staphylococcus hominis230.075Acinetobacter baumannii130.057Pseudomonas aeruginosa120.046Staphylococcus aureus130.042Staphylococcus hominis110.048Staphylococcus aureus110.042Enterococcus faecalis120.039Enterococcus faecium100.044Staphylococcus hominis100.038Acinetobacter baumannii110.036Staphylococcus aureus90.039Enterobacter cloacae90.035Pseudomonas aeruginosa70.023Staphylococcus haemolyticus90.039Enterococcus faecium80.031Enterobacter cloacae60.020Pseudomonas aeruginosa70.031Staphylococcus haemolyticus40.015Enterococcus faecium40.013Burkholderia cepacia30.013Other bacteria490.188Other bacteria620.202Other bacteria500.218Total2601.000Total3071.000Total2291.000Table 6
Composition of urine specimen isolates in 2017, 2018, and 2019.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionEscherichia coli2580.422Escherichia coli2620.393Escherichia coli2650.377Klebsiella pneumoniae750.123Enterococcus faecium690.103Enterococcus faecium860.123Enterococcus faecium700.114Enterococcus faecalis630.094Enterococcus faecalis590.084Enterococcus faecalis630.103Klebsiella pneumoniae510.076Klebsiella pneumoniae510.073Pseudomonas aeruginosa340.056Pseudomonas aeruginosa340.051Pseudomonas aeruginosa340.048Staphylococcus epidermidis220.036Staphylococcus epidermidis210.031Staphylococcus epidermidis280.040Proteus mirabilis170.028Proteus mirabilis180.027Streptococcus agalactiae180.026Enterobacter cloacae150.025Streptococcus agalactiae160.024Proteus mirabilis150.021Streptococcus agalactiae140.023Morganella morganii120.018Acinetobacter haemolyticus140.020Acinetobacter haemolyticus110.018Corynebacterium glutamicum110.016Enterobacter cloacae120.017Other bacteria330.054Other bacteria1100.165Other bacteria1200.171Total6121.000Total6671.000Total7021.000Table 7
Composition of sputum specimen isolates in 2017, 2018, and 2019.
201720182019BacteriaNumberProportionBacteriaNumberProportionBacteriaNumberProportionPseudomonas aeruginosa2800.233Klebsiella pneumoniae2860.224Pseudomonas aeruginosa2950.220Klebsiella pneumoniae2620.218Pseudomonas aeruginosa2820.221Acinetobacter baumannii2470.185Acinetobacter baumannii2030.169Acinetobacter baumannii1830.143Klebsiella pneumoniae2340.175Staphylococcus aureus1000.083Staphylococcus aureus1100.086Staphylococcus aureus1080.081Escherichia coli850.071Stenostomonas maltophilia710.056Stenostomonas maltophilia1030.077Stenostomonas maltophilia620.052Escherichia coli600.047Escherichia coli590.044Corynebacterium striatum480.040Corynebacterium striatum500.039Enterobacter cloacae520.039Enterobacter cloacae410.034Enterobacter cloacae480.038Corynebacterium striatum420.031Streptococcus pneumoniae360.030Streptococcus pneumoniae330.026Haemophilus influenzae400.030Burkholderia cepacia290.024Burkholderia cepacia310.024Burkholderia cepacia300.022Other bacteria540.045Other bacteria1230.096Other bacteria1280.096Total12001.000Total12771.000Total13381.000It was found thatEscherichia coli (39.7%), Enterococcus faecium (11.3%), Enterococcus faecalis (9.4%), and Klebsiella pneumoniae (9.1%) ranked in the top four pathogenic bacteria from urine sample isolates. The most predominant pathogen in the urine samples was Escherichia coli accounting for 42.2%, 39.3%, and 37.8% from 2017 to 2019. Within the three years, compared to the blood and sputum samples, Escherichia coli accounted for the highest proportion of the urine samples isolated strains. Enterococcus faecium and Enterococcus faecalis have a higher proportion in urine than in blood samples, and they were not present in samples (Table 6).Pseudomonas aeruginosa (22.5%), Klebsiella pneumoniae (20.6%), and Acinetobacter baumannii (16.6%) were the top three in sputum sample isolated strains. Staphylococcus aureus (8.3%) and Stenotrophomonas maltophilia (6.1%) were also common in sputum specimens and ranked fourth and fifth. Moreover, Stenotrophomonas maltophilia is a pathogen specific to sputum samples, and its proportion was increasing from 5.2% to 7.7% during 2017 to 2019 (Table 7).


## 3.3. Antibiotic Resistance Analysis

Combining the isolation of the pathogenic bacteria from the three hospital departments from 2017 to 2019 and the distribution of isolated strains from blood, urine and sputum specimens, it can be seen that the bacteria that are susceptible and have a high titer in each specimen were mainlyEscherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter baumannii and their antibiotic resistance was found to be unchanged.From 2017 to 2019,Escherichia coli was generally resistant to trimethoprim and minocycline, with a resistance rate of up to 100% and with high sensitivity to imipenem, amikacin, ertapenem, and other drugs (Table 8). The resistance rate of Klebsiella pneumoniae to trimethoprim, cefuroxime, piperacillin, piperacillin-sulbactam, and ampicillin was higher than 90%. However, its resistance to cefoperazone-sulbactam, ertapenem, and amikacin was lower than 40% (Table 9). The resistance of Pseudomonas aeruginosa to most antibiotics such as piperacillin, ciprofloxacin, amikacin, and tobramycin was less than 30%, and resistance to polymyxin B was less than 5%, and even reached a sensitivity of 100% in 2018 and 2019 (Table 10). Acinetobacter baumannii had high sensitivity to tigecycline and minocycline of less than 30%, and the resistance rate to tigecycline was zero but was greater than 60% resistant to many drugs such as piperacillin, ceftazidime, gentamicin, and imipenem (Table 11). Staphylococcus aureus had the highest resistance rate to penicillin, at more than 80%, and the resistance rate to erythromycin was approximately 60%. However, no strains were resistant to antibiotics such as vancomycin, teicoplanin, tigecycline, and linezolid (Table 12).Table 8
Drug resistance rates ofEscherichia coli from 2017 to 2019.
201720182019Escherichia coliDrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Trimethoprim100Ampicillin-sulbactam71.3Ampicillin-sulbactam76.8Minocycline100Ciprofloxacin60.4Cefuroxime54.3Cefazolin90.27Levofloxacin55.9Ciprofloxacin54.1Ampicillin87.7Ceftriaxone55.2Levofloxacin49.9Ceftriaxone78Cotrimoxazole49.5Ceftriaxone48.3Ciprofloxacin78Gentamicin39.6Cotrimoxazole45.3Levofloxacin73.2Aztreonam36.5Gentamicin34.9Ampicillin-sulbactam65.9Ceftazidime26.4Aztreonam27.9Compound sulfadiazine64Cefepime23.3Ceftazidime20.3Aztreonam55.2Tobramycin14.3Cefepime17.4Piperacillin50Cefoperazone-sulbactam7.9Tobramycin10.5Tobramycin49.2Fosfomycin7Fosfomycin7.0Cefepime36.4Ertapenem5.2Cefoperazone-sulbactam3.4Gentamicin36.3Piperacillin-tazobactam4.6Nitrofurantoin2.5Cefotaxime32.4Imipenem4Piperacillin-tazobactam2.4Ceftazidime32Nitrofurantoin2.9Amikacin1.7Amikacin1.4Ertapenem0.7Imipenem0.6Table 9
Drug resistance rates ofKlebsiella pneumoniae from 2017 to 2019.
201720182019DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Klebsiella pneumoniaeTrimethoprim100Ampicillin-sulbactam71.7Ampicillin-sulbactam66.7Cefuroxime100Nitrofurantoin34.8Nitrofurantoin33.9Piperacillin100Fosfomycin34.1Cotrimoxazole29.6Piperacillin-sulbactam100Ceftriaxone30Aztreonam26.7Ampicillin96.3Cotrimoxazole27Cotrimoxazole23.8Cefazolin81.7Levofloxacin25.6Ciprofloxacin22.2Nitrofurantoin78.8Aztreonam25.2Ceftazidime20.9Fosfomycin72.5Ciprofloxacin25.1Levofloxacin19.9Ampicillin-sulbactam70.8Ceftazidime23.9Gentamicin18.9Ceftriaxone65.7Gentamicin22.7Cefepime17.1Cefepime53.5Cefepime22.2Tobramycin13.5Tobramycin52.6Tobramycin19Imipenem11.8Aztreonam51.3Cefoperazone-sulbactam18.9Piperacillin-tazobactam11.3Compound sulfadiazine50.8Imipenem17.8Cefoperazone-sulbactam11.1Ceftazidime50Ertapenem17.3Ertapenem8.8Cefotaxime50Piperacillin-tazobactam17Amikacin6.0Ciprofloxacin49.2Amikacin12.2Tigecycline0.0Cefoperazone48.6Levofloxacin47.2Gentamicin46.1Piperacillin-tazobactam44.3Imipenem40.2Cefoperazone-sulbactam32.4Table 10
Drug resistance rates ofPseudomonas aeruginosa from 2017 to 2019.
201720182019DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Pseudomonas aeruginosaAztreonam37.2Meropenem22Meropenem18.4Cefepime34Aztreonam18.8Imipenem15.8Imipenem33.5Levofloxacin18.8Levofloxacin13.7Piperacillin29.1Cefepime18.7Aztreonam13.4Meropenem27.1Imipenem18.2Gentamicin12.2Gentamicin25.2Gentamicin15.6Cefepime12.1Piperacillin-sulbactam25.1Ciprofloxacin13.5Piperacillin11.6Ceftazidime23.7Piperacillin12.8Cefoperazone-sulbactam9.2Levofloxacin20Ceftazidime12.2Ciprofloxacin8.6Ciprofloxacin18.4Cefoperazone-sulbactam11.1Tobramycin7.7Tobramycin13.5Tobramycin9.9Piperacillin-tazobactam7.2Amikacin10Amikacin9.2Ceftazidime6.8Polymyxin B2.5Piperacillin-tazobactam8.6Amikacin3.5Polymyxin B0Polymyxin B0.0Table 11
Drug resistance rates ofAcinetobacter baumannii from 2017 to 2019.
201720182019DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Acinetobacter baumanniiPiperacillin73.5Piperacillin63Piperacillin73.2Moxifloxacin74.7Moxifloxacin63.8Imipenem72.2Cefepime73.6Cefepime63.7Piperacillin-tazobactam71.2Piperacillin-tazobactam74.6Piperacillin-tazobactam63.6Cefepime70.0Ceftazidime73.9Ceftazidime63.6Ceftazidime69.8Imipenem73.1Imipenem62.7Gentamicin69.6Levofloxacin72.5Levofloxacin62.6Ciprofloxacin67.7Gentamicin69.7Gentamicin60.6Levofloxacin61.5Amikacin66.5Amikacin58.1Tobramycin55.4Tobramycin65.3Tobramycin57.2Amikacin42.2Cefoperazone-sulbactam37.3Cefoperazone-sulbactam32.9Minocycline27.3Minocycline25.6Minocycline21.5Tigecycline0.0Tigecycline0Tigecycline0Table 12
Drug resistance rates ofStaphylococcus aureus from 2017 to 2019.
201720182019DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)DrugsDrug resistance rate (%)Staphylococcus aureusPenicillin91.3Penicillin87.6Penicillin89.6Erythromycin61.8Erythromycin59.8Erythromycin62.7Clindamycin58.6Clindamycin57.1Clindamycin58.4Oxacillin35.2Oxacillin32.3Oxacillin36.8Tetracycline24.2Tetracycline23.2Cotrimoxazole24.1Cotrimoxazole17.3Cotrimoxazole16.3Tetracycline18.3Ciprofloxacin16.5Ciprofloxacin15Ciprofloxacin18.0Gentamicin14.8Gentamicin14Moxifloxacin15.7Moxifloxacin14Moxifloxacin13.3Levofloxacin14.2Levofloxacin13Levofloxacin10Gentamicin14.1Rifampicin3.5Rifampicin3.3Rifampicin3.7Nitrofurantoin1.2Nitrofurantoin0.8Nitrofurantoin0.8Linezolid0Linezolid0Linezolid0.0Vancomycin0Vancomycin0Vancomycin0.0Teicoplanin0Teicoplanin0Teicoplanin0.0Tigecycline0Tigecycline0Tigecycline0.0


## 3.4. Multidrug Resistance Analysis

Analysis of multiple drug resistance for the main pathogenic bacteria in our hospital in 2017 is shown in Figure1. In 2017, a total of 1181 multidrug-resistant bacterial strains of Enterobacteriaceae were isolated, accounting for the largest proportion of the detected multidrug-resistant strains; of which 491 strains of multidrug-resistant organisms (MDRO) accounted for 41.6%, and no XDR and PDR strains were found (Figure 1(a)). ESBLs-KPN is highly resistant to amoxicillin and ceftriaxone, with resistance rates of 100% and 99.4%, respectively, and the sensitivity to ertapenem, imipenem, and piperacillin/tazobactam was above 95% (Table 13). The resistance rate of CRE-KPN to all drugs was above 50%, among which ampicillin, cefoperazone-sulbactam, ampicillin-sulbactam, ceftazidime, and ceftriaxone were all resistant by 100%. The resistance rates to nitrofurantoin, ciprofloxacin, levofloxacin, aztreonam, and cefepime were all greater than 95% (Table 14) and the resistance rates of ESBLs-producing Escherichia coli (ESBLs-ECO) to ampicillin and ceftriaxone were over 99%, and sensitivities to drugs such as amikacin, nitrofurantoin, and cefepime were all greater than 60%, with no strains being resistant to ertapenem, piperacillin-tazobactam, or imipenem (Table 15). A total of 263 strains of Acinetobacter were isolated, including 150 strains of MDRO, accounting for 57%, and no XDR and PDR strains were found (Figure 1(b)). The resistance rate of MDR-Acinetobacter baumannii (MDR-AB) to levofloxacin, moxifloxacin, and ampicillin was up to 100%, and the drug resistance to cotrimoxazole, amikacin, and other drugs was also more than 70% (Table 16). Of the 395 strains of Pseudomonas aeruginosa isolated, 90 strains of MDRO accounted for 22.8%, and 21 strains of XDR accounted for 5.3%. No PDR strain was found (Figure 1(c)). MDR-Pseudomonas aeruginosa (MDR-PAE) showed more than 97% resistance to ciprofloxacin, piperacillin, and amtronam, among which the resistance rate for ceftazidime, imipenem, and levofloxacin was 100%. While sensitivity to polymyxin B and tobramycin had a sensitivity of 98.7% (Table 17). A total of 732 strains of Staphylococcus were isolated, of which 316 were MDRO strains, accounting for 43.2%, and no XDR and PDR strains were found (Figure 1(d)). Methicillin-resistant Staphylococcus aureus (MRSA) was 100% resistant to benzacillin, 60% resistant to erythromycin, 50% resistant to ciprofloxacin, clindamycin, and tetracycline, but 100% sensitive to linezolid and vancomycin (Table 18).Figure 1
Analysis of multiple drug resistance for the main pathogenic bacteria in our hospital in 2017. (a) The analysis of multiple drug resistance ofEnterobacteriaceae bacteria. (b) The analysis of multiple drug resistance of Acinetobacter bacteria. (c) The analysis of multiple drug resistance of Pseudomonas aeruginosa. (d) The analysis of multiple drug resistance of Staphylococcus bacteria.
(a)(b)(c)(d)Table 13
Analysis of multiple drug resistance rate of ESBLs-KPN in 2017.
DrugsDrug resistance rate (%)ESBLs-KPNErtapenem1.8Imipenem2.8Piperacillin-tazobactam8Amikacin9.7Cefoperazone-sulbactam21.7Tobramycin27.8Gentamicin40.9Fosfomycin42.3Nitrofurantoin48.3Levofloxacin49.4Cefepime50Ciprofloxacin60.8Ceftazidime63.1Aztreonam73.9Cotrimoxazole80.7Ampicillin-sulbactam90.3Ceftriaxone99.4Ampicillin100Table 14
Analysis of multiple drug resistance rates of CRE-KPN in 2017.
DrugsDrug resistance rate (%)CRE-KPNCotrimoxazole52.7Fosfomycin60Amikacin72.8Tobramycin79Gentamicin82.1Nitrofurantoin96.3Ciprofloxacin98.3Levofloxacin98.3Aztreonam98.6Cefepime98.9Piperacillin-tazobactam99.4Ampicillin100Cefoperazone-sulbactam100Ampicillin-sulbactam100Ceftazidime100Ceftriaxone100Ertapenem100Imipenem100Table 15
Analysis of multiple drug resistance rate of ESBLs-ECO in 2017.
DrugsDrug resistance rate (%)ESBLs-ECOErtapenem0Piperacillin-tazobactam0Imipenem0ASmikacin2.2Nitrofurantoin3Cefoperazone-sulbactam6.4Fosfomycin12.3Tobramycin17.5Cefepime32.9Gentamicin41.1Ceftazidime43.4Cotrimoxazole53.9Aztreonam66.3Ampicillin-sulbactam66.8Levofloxacin71.6Ciprofloxacin75.8Ampicillin99.3Ceftriaxone99.5Table 16
Analysis of multiple drug resistance rate of MDR-AB in 2017.
DrugsDrug resistance rate (%)MDR-ABCotrimoxazole74.7Amikacin78.1Tobramycin81.1Gentamicin82.2Minocycline84.3Ampicillin100Piperacillin100Piperacillin-tazobactam100Ceftazidime100Ceftriaxone100Cefotaxime100Cefepime100Aztreonam100Table 17
Analysis of multiple drug resistance rate of MDR-PAE in 2017.
DrugsDrug resistance rate (%)MDR-PAEPolymyxin B1.3Tobramycin19.4Amikacin46.6Gentamicin69.2Cefoperazone-sulbactam81Piperacillin/tazobactam93.3Ciprofloxacin97.7Piperacillin99.3Aztreonam99.3Cefepime99.7Ceftazidime100Imipenem100Levofloxacin100Table 18
Analysis of multiple drug resistance rate of MRSA in 2017.
DrugsDrugresistance rate (%)MRSALinezolid0Vancomycin0Nitrofurantoin4.5Cotrimoxazole10Rifampicin28.9Gentamicin39.1Levofloxacin46.9Moxifloxacin48.6Ciprofloxacin51.1Clindamycin51.7Tetracycline52.5Erythromycin61.1Oxacillin100In 2018, a total of 1293 strains of multidrug-resistant bacteria such asEnterobacteriaceae were isolated, of which MDRO (574 strains) accounted for 44.4%, while XDR and PDR strains were not found (Figure 2(a)). A total of 270 strains of Acinetobacter were isolated, including 145 strains of MDRO, accounting for 53.7%, and no XDR and PDR strains were found (Figure 2(b)). A total of 406 strains of Pseudomonas aeruginosa were isolated, among which 107 strains of MDRO accounted for 26.4%, while 26 strains of XDR accounted for 6.4%, and no PDR strains were found (Figure 2(c)). A total of 704 strains of Staphylococcus bacteria were isolated, including 300 strains (42.6%) of MDRO, with no XDR and PDR strains being found (Figure 2(d)). The resistance rates of MRSA to benzacillin and penicillin were 100% and 99.2%, respectively. No strains were found to be resistant to linezolid, vancomycin, teicoplanin, and tigecycline (Table 19).Figure 2
Analysis of multiple drug resistance for the main pathogenic bacteria in our hospital in 2018. (a) The analysis of multiple drug resistance ofEnterobacteriaceae bacteria. (b) The analysis of multiple drug resistance of Acinetobacter bacteria. (c) The analysis of multiple drug resistance of Pseudomonas aeruginosa. (d) The analysis of multiple drug resistance of Staphylococcus bacteria.
(a)(b)(c)(d)Table 19
Analysis of multiple drug resistance rate of MRSA in 2018.
DrugsDrug resistance rate (%)MRSAPenicillin100Oxacillin100Erythromycin74.3Clindamycin69.1Tetracycline38.4Ciprofloxacin31.8Moxifloxacin30.3Levofloxacin28.3Cotrimoxazole23.8Gentamicin20.5Rifampicin9.9Nitrofurantoin1.3Linezolid0Vancomycin0Teicoplanin0Tigecycline0As shown in Figure3(a), in 2019, a total of 1166 strains of Enterobacteriaceae were isolated, of which 484 strains were isolated by MDR, accounting for 41.5%, and no XDR and PDR strains were found. The high resistance of ESBLs-producing Enterobacteriaceae to ceftriaxone and amcarcillin-sulbactam was observed, both more than 95%. Its drug resistance to cephalosporin, tobramycin, and furantoin was less than 40%, among which the drug resistance rate for tigecycline, imipenem, and amikacin was less than 5% (Table 20). Carbapenem-resistant (CRE) Enterobacteriaceae bacteria showed the highest resistance to amcarcillin-sulbactam (97.1%), and the resistance rate to most drugs ranged from 70% to 90%, but they were sensitive to tigecycline and amikacin (Table 21). A total of 325 strains of Acinetobacter were isolated, of which 213 strains were isolated from MDR, accounting for 65.5%, and no XDR and PDR strains were found (Figure 3(b)). A total of 409 strains of Pseudomonas aeruginosa were isolated, of which 86 strains were isolated by MDR, accounting for 21.0%, and 23 strains were isolated by XDR, accounting for 5.6%, with no PDR strain being found (Figure 3(c)). A total of 768 strains of Staphylococcus were isolated, of which 356 strains were isolated by MDRO, accounting for 46.4%, and no XDR and PDR strains were found (Figure 3(d)). Similar to 2018, MRSA showed 100% resistance to penicillin and benzacillin, and the sensitivity to tetracycline, ciprofloxacin, and other drugs was more than 60%, and no strains resistant to linezolid, vancomycin, and other four drugs were found (Table 22).Figure 3
Analysis of multiple drug resistance for the main pathogenic bacteria in our hospital in 2019. (a) The analysis of multiple drug resistance ofEnterobacteriaceae bacteria. (b) The analysis of multiple drug resistance of Acinetobacter bacteria. (c) The analysis of multiple drug resistance of Pseudomonas aeruginosa. (d) The analysis of multiple drug resistance of Staphylococcus bacteria.
(a)(b)(c)(d)Table 20
Analysis of multiple drug resistance rate of ESBLs in 2019.
DrugsDrug resistance rate (%)ESBLsCeftriaxone96.7Ampicillin-sulbactam96.5Ciprofloxacin67.2Aztreonam64.7Levofloxacin61.3Cotrimoxazole56.2Ceftazidime44.0Gentamicin43.1Cefepime36.2Tobramycin21.5Nitrofurantoin14.2Fosfomycin13.6Cefoperazone-sulbactam8.2Piperacillin-tazobactam4.0Ertapenem3.0Amikacin2.7Imipenem1.0Table 21
Analysis of multiple drug resistance rate of CREs in 2019.
DrugsDrug resistance rate (%)CREsAmpicillin-sulbactam97.1Imipenem88.9Ceftriaxone84.9Ertapenem83.6Ceftazidime82.7Nitrofurantoin79.4Ciprofloxacin78.9Aztreonam77.3Levofloxacin76.8Cefepime75.8Piperacillin-tazobactam74.5Cefoperazone-sulbactam70.4Gentamicin53.5Tobramycin50.0Cotrimoxazole43.3Amikacin31.6Tigecycline0.0Table 22
Analysis of multiple drug resistance rate of MRSA in 2019.
DrugsDrug resistance rate (%)MRSAOxacillin100Penicillin99.2Erythromycin79.5Clindamycin76.5Tetracycline51.6Ciprofloxacin31.5Moxifloxacin29.5Levofloxacin28.2Gentamicin20.3Rifampicin10.6Cotrimoxazole6.1Nitrofurantoin2.3Linezolid0Vancomycin0Teicoplanin0Tigecycline0


## 3.5. The Trend of Isolate Major Multidrug-Resistant Bacteria in Our Hospital in the Past Four Years

As shown in Figure4, the isolation rate of MDR-AB, which remained at the top for three years, declined in 2018 but increased again in 2019. ESBLs-ranked second in the three-year average separation rate, while MDR-PAB showed a continuous downward trend, whereas MRSA was the opposite, with a continuous increase being observed and CRE also exhibited a rise.Figure 4
The trend of separation rate (%) of main multidrug-resistant strains in our hospital in recent four years.


## 4. Discussion

The discovery of antibiotics in the last century is considered one of the most important achievements in the history of medicine, and its use has greatly reduced morbidity and mortality associated with bacterial infections [2]. However, the evolution of new bacterial strains, as well as the excessive use and reckless consumption of antibiotics, has led to the development of antibiotic resistance. Multidrug resistance is a potential threat worldwide and is escalating at an extremely high rate [9]. Poor public health conditions, lack of awareness concerning drug-resistant bacteria among the public, high incidences of disease, ease of access, and their misuse are the major factors exacerbating the problem [5]. In the context of antibiotic resistance, due to the emergence and increased prevalence of multidrug-resistant (MDR) superbugs such as Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae, human health is being treated as a priority for the health of interdependent animals and related environments and is estimated to impose a significant health burden on the global population [10]. Therefore, we identified the clinical isolates obtained in the hospital from 2017 to 2019, carried out drug susceptibility tests and epidemiological infection analysis, obtained information about the pathogens for the whole hospital, and conducted a summary analysis, hoping to promote the rational use of antibiotics and play an active role in reducing the emergence of resistant bacteria in hospitals and controlling the spread of multidrug-resistant strains.From 2017 to 2019, the isolation of pathogenic bacteria in the three departments of the hospital showed that the top five pathogens remained unchanged. These includedEscherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii, which, together with Enterobacter faecium as the most problematic clinical pathogens, were summarized as “ESKAPE” bugs by Louis Rice [11]. ESKAPEE pathogens have developed resistance mechanisms against most antibiotic treatments, including those that are the last line of defense, such as carbapenems and polymyxins [12]. According to the results of pathogen isolation in three ICU departments in the past three years, the five pathogens mentioned above always ranked among the top eight. The total number of isolates from central ICUs was always higher than that from specialized ICUs, namely RICUs and ICUs. The isolation rates of Pseudomonas aeruginosa, Klebsiella pneumoniae, and Stenotrophomonas maltophilia in the RICUs were the highest among the three ICU wards because they were all closely associated with lower respiratory tract infections [13]. In the last three years, the average proportion of Pseudomonas aeruginosa isolates was 17.5% in RICUs, similar to studies in the United States during the early years that found P. aeruginosa (17.0%) as a relatively common organism isolated in RICU with respiratory infections [14]. In EICUs, Acinetobacter baumannii occupies the highest isolation rate among the three ICU wards, and critically ill patients tend to be more susceptible to infection. Because Acinetobacter baumannii infection is associated with invasive surgery, the reason for hospitalization includes host factors, length of ICU stay, and prior use of broad-spectrum antibiotics [15].The composition of isolates from different sources from 2017 to 2019 was analyzed, and we found that the isolation rate ofStaphylococcus epidermidis was higher in blood samples than in urine samples, but no isolates were found in sputum samples. Staphylococcus hominis isolates were only present in blood samples, and as previously reported, these two bacteria both produce biofilms that allow them to adhere to internal medical devices and are commonly isolated from bloodstream infections [16, 17]. Among the three sources, blood, urine, and sputum, Escherichia coli isolates accounted for the highest proportion in urine specimens. Enterococcus faecium and Enterococcus faecalis were distributed at higher levels in urine samples than in blood samples and were absent in sputum samples. As previously reported, the above three bacteria are the main pathogenic bacteria of urinary tract infections [18, 19]. The top five frequent isolates from sputum samples are Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, and Stenotrophomonas maltophilia, and this is similar to previous findings [13].Measures for the management and clinical application of antibiotics in China are as follows: according to the notice of the Health and Family Planning Commission of the People’s Republic of China on further strengthening the management of the clinical application of antibacterial drugs to effectively curb bacterial resistance, medical institutions should carry out monitoring of bacterial resistance, establish bacterial resistance early warning mechanisms, and take the following corresponding measures: (1) If the antimicrobial drug resistance rate of the main target bacteria exceeds 30%, warning information should be reported to the medical staff of the institution in a timely manner; (2) Antibiotics with a resistance rate of more than 40% for the major target bacteria should be used cautiously and empirically; (3) Antibiotics with drug resistance rates of over 50% for the major target bacteria should be selected according to drug sensitivity test results; (4) Clinical application of antibacterial drugs with drug resistance rates exceeding 75% for the main target bacteria should be suspended, and clinical application should be decided according to results based on bacterial resistance.Regarding antibiotic resistance,Escherichia coli showed low resistance to most third-generation cephalosporins and aminoglycoside antibiotics, the resistance rate is between 30% and 50%, which is similar to the study conducted by Miller et al. [20]. It is highly sensitive to imipenem, nitrofurantoin, piperacillin-tazobactam, and amikacin and is recommended for clinical use. Klebsiella pneumoniae, also belonging to the Enterobacteriaceae family, exhibited low resistance to imipenem and cefoperazone-sulbactam. Similar antibiotic resistance rates have been reported by Liu et al. [21]. In 2018-2019, its resistance rate to amikacin, piperacillin-tazobactam, ertapenem, and other antibacterial drugs was less than 20%, indicating a wide range of drug choices that can be used as a good choice for current clinical treatment. Pseudomonas aeruginosa showed low to moderate rates of drug resistance to commonly used antipseudomonal drugs and most antibiotics such as carbapenems, amikacin, cefoperazone-sulbactam, piperacillin-tazobactam, and ceftazidime, were less than 30%, similar to the results of previous studies [22]. Thus, there are many options for medication. Especially in 2018 and 2019, no strains resistant to polymyxin B were found, and therefore, it is the recommended drug for clinical treatment. The drug resistance of Acinetobacter baumannii is relatively serious, and the resistance rate to most antibiotics is greater than 60%. Therefore, carbapenems are not recommended for single Acinetobacter baumannii infections, which can easily increase the risk of multidrug resistance. Acinetobacter baumannii has relatively high sensitivity to cefoperazone-sulbactam, which is the first choice for empirical medication in confirmed cases of infection to improve the curative effect. Staphylococcus aureus is resistant to penicillin by more than 85%, so the clinical application for these target bacteria should be suspended. No resistant strains were found to linezolid, vancomycin, teicoranin, and tigecycline. Hence they represent a good choice for empirical treatment.From 2017 to 2019, the important multidrug-resistant bacteria in our hospital included extended-spectrumβ-lactamases (ESBLs)-producing Klebsiella pneumoniae (ESBLs-KPN) and carbapenem-resistant Klebsiella pneumoniae (CRE-KPN), ESBLs-producing Escherichia coli (ESBLs-ECO) and carbapenem-resistant Escherichia coli (CRE-ECO), multidrug-resistant Acinetobacter baumannii (MDR-AB), multidrug-resistant Pseudomonas aeruginosa (MDR-PAE), and methicillin-resistant Staphylococcus aureus (MRSA), which were mainly detected by Chinese Antimicrobial Resistance Surveillance System.Acinetobacter baumannii, Enterobacteriaceae, and Pseudomonas aeruginosa are the common clinical carbapenem-resistant Gram-negative bacteria. Several drugs that are active against carbapenem-resistant Acinetobacter baumannii have been approved for clinical use or have entered late-stage clinical development, including eravacycline, cefiderocol, and plazomicin [23]. For MDR-AB, carbapenems are not recommended for empirical use, not only because of their high resistance rate, but more importantly, they further increase the risk of multidrug resistance caused by high intensity antimicrobial use. For pan-resistant Acinetobacter baumannii, some clinical departments have chosen tigecycline for treatment, but CLSI (American Institute of Clinical and Laboratory Standards) lacks the criteria for determining the susceptibility of Acinetobacter baumannii to tigecycline, and its efficacy remains to be validated.The detection rate of multidrug-resistant bacteria in theEnterobacteriaceae family was the highest and was mainly concentrated on the detection of ESBLs-ECO, ESBLs-KPN, CRE-KPN, and CRE-ECO. The number of ESBLs-KPN and CRE-KPN isolates ranked first in 2017, followed by MDR-AB, and these results are in agreement with those obtained by Talaat et al. [24], who showed that the most predominant Gram-rods in the hospital were Klebsiella pneumoniae (28.7%) and Acinetobacter sp. (13.7%). ESBLs-producing isolates showed resistance to β-lactam antibiotics, including third-generation cephalosporins; in addition, they often exhibit resistance to other classes of drugs such as aminoglycosides, cotrimoxazole, and fluoroquinolones [25]. Tigecycline and imipenem can be used as empirical drugs for ESBL-producing bacteria. It should be emphasized that ESBLs-ECO and ESBLs-KPN have high drug resistance rates to ceftriaxone and amcarcillin-sulbactam, and the risk of induced drug resistance is also very high. Therefore, the drug sensitivity test results should be referred to for selection. The detection rate of CRE bacteria in 2019 was higher than the national average in 2018, and therefore, it is necessary to reduce the overuse of carbapenem antibiotics and prevent the spread of bacteria in hospitals and regions. The resistance rate of CRE bacteria to amcarcillin-sulbactam exceeded 95%, and their clinical use should be suspended. No strains sensitive to tigecycline have been found, and they can be used as clinically recommended drugs, usually in combination with other drugs. Enterobacteriaceae represents a key family of carbapenem-resistant bacteria. Colistin, tigecycline, ceftazidime-avibactam, plazomicin, eravacycline, and cefiderocol can all be used for their clinical treatment [23].The average separation rate of MDR-PAE ranks third (31.7%), with no major fluctuations in recent years. It is also a common clinical carbapenem-resistant Gram-negative bacterium. Our results showed that MDR-PAE and XDR-PAE occupy 23.4% and 5.8% of the average proportion ofPseudomonas aeruginosa isolates, higher than the results from other studies. In 2015, the European Centers for Disease Prevention and Control stated that MDR-PAE and XDR-PAE isolates accounted for 13.7% and 5.5% [26]. The high prevalence of resistant species in developing countries could be due to noncompliance with infection control regulations and to the lack of or an imperfect antibiotic policy. Studies [26] have shown that multiple antibiotic combinations can be used as a clinical solution for MDR-PAE and XDR-PAE infections. Previous studies [27, 28] have reported that combinations of polymyxins with these anti-pseudomonas drugs (such as imipenem, piperacillin, aztreonam, ceftazidime, or ciprofloxacin) are more effective than polymyxins alone against MDR-PAE, providing a reference for the treatment of MDR-PAE infection. Yadav et al. [29] demonstrated substantially enhanced death in vivo against an MDR-PAE clinical isolate with an optimized imipenem-plus-tobramycin combination regimen, which was an alternative to colistin therapy, especially in patients with renal insufficiency. In addition, drugs such as cefiderocol and fosfomycin are potential treatment options in the near future [26]. The available clinical solution for MDR-PAE infections requires a precise diagnostic and combination antibiotic therapy based on diagnostics. Several infections which are recurrent need additional care to stop the proliferation of MDR-PAE contaminating the surrounding environment.MRSA is a virulent and difficult-to-treat “superbug,” and our results show that MRSA accounted for 30% to 50% ofStaphylococcus aureus infections in hospital settings over the three-year period, which was slightly higher than the 25% to 50% reported in previous studies [30]. As previously reported [31], the infection rates of resistant Staphylococcus, Pseudomonas, Acinetobacter, and Klebsiella vary by country and region, with Asia being higher than North America and Western Europe. This may be due to the apparent wide variations in health care systems, ICU facilities, and policies for infectious disease control in the different geographical regions. Drug resistance, however, is consistent with previous research results, where MRSA is resistant to penicillin-like beta-lactam antibiotics [32], and the resistance to penicillin was observed to be as high as 99.2%, and clinical use of this target bacterium should be suspended. Many drugs remain active against MRSA, including glycopeptides (vancomycin and teicoranin), linezolid, and tigecycline, to which no resistant strains have been found and are, therefore, good choices for empirical treatment. Even some newer lactams, such as ceftazlorin and cefdipropanol, can be used as treatment options for MRSA [33].With the promotion of rational applications for antibiotics, the isolation spectrum of pathogenic bacteria and the isolation rate of multidrug-resistant strains in our hospital have also changed accordingly, mainly reflected by the fact that although the isolation and drug resistance rates of MDR-AB always ranked first. After 2016, the separation rate of MDR-AB decreased significantly, which is probably due to the implementation of the Guiding Principles of Clinical Use of Antibiotics in 2015. The prevalence of CREEnterobacteriaceae bacteria has increased in recent years, which is consistent with the national drug resistance monitoring information. The isolation rates of other bacteria did not fluctuate greatly, but the epidemiology of these bacteria still needs to be addressed.The emergence of multidrug-resistant bacteria, or superbugs, poses a serious threat to public health and requires multilevel efforts to prevent them from overcoming antibiotic resistance. Governments must allocate sufficient funds to improve and develop new drug products, monitor the use of antibiotics, and establish strict policies and regulations. In addition, infection control measures must be strictly implemented in hospitals, but management practices must be considered for the use of antibiotics and microbicides and appropriate disposal or discharge of medical waste. Clinicians should avoid prescribing unnecessary and excessive antibiotics to patients with normal infections and advise patients to follow good hygiene practices such as hand washing and appropriate infection control measures. As an individual, we can take antibiotics that are prescribed only by our doctors, take them exactly as prescribed, and use them sensibly. Efforts to address the spread of antibiotic resistance include limiting the overuse of antibiotics in the food and animal sectors.Nonantibiotic strategies for the treatment of antibiotic-resistant pathogens have been reported, such as gene editing techniques, immunotherapies, and vaccines, and antivirulence inhibitor bacteriophages [5, 10]. Antimicrobial adjuvants, fecal microbiota transplant (FMT), and competitive exclusion of pathogens through genetically modified probiotics and postbiotics are prospective alternative, unconventional strategies [5]. In addition, epidemiological and surveillance studies should be carried out and powerful tools should be used to deepen our understanding of antibiotic resistance and provide a timely and precise diagnosis of antibiotic use and consumption. Therefore, a multidisciplinary approach is needed to eliminate the serious threat of multidrug resistance.However, this study also has some limitations. When analyzing multiple drug resistance, multiple bacteria in the same family and genus were not studied separately. In the future, a specific analysis should be carried out for important multidrug-resistant pathogens.


## 5. Conclusion

The distribution of pathogenic bacteria in different hospital departments and sample sources is variable. Therefore, targeted prevention and control of key pathogenic bacteria in different hospital departments must be carried out. Understanding the drug resistance and multiple drug resistance of the main pathogenic bacteria can provide guidance for the rational use of antibiotics in clinic.



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