bluuebunny/crossref_metadata_2025_split huggingface dataset:
190. Meta-analysis of Impact of Follow-up Blood Cultures on Mortality in Patients with Gram-negative Bacteremia
Authors: Eljaaly Khalid 
Published: November 2023

Abstract

Background
It is not clear if follow-up blood cultures are beneficial in patients with Gram-negative bacteremia. It may improve clinical outcomes but have some drawbacks such as the possibility of inaccurate positive findings and extending the length of hospital stay and duration of antibiotic therapy. The aim of this meta-analysis was to evaluate the impact of follow-up blood cultures on mortality in patients with Gram-negative bacteremia.

Methods
PubMed and EMBASE databases were searched from inception to Jan 2023 for randomized controlled trials or observational studies comparing the mortality in patients with Gram-negative bacteremia who had follow-up blood cultures obtained versus those without these cultures. We estimated odds ratios (ORs) with 95% confidence intervals (CIs) using random-effects models and assessed for heterogeneity (I2).

Results
A total of six observational studies were included, while no randomized controlled trials were identified. The total number of patients was 4,631. One study used 28-day mortality, two studies used 30-day mortality, and three studies used in-hospital mortality. Follow-up blood cultures were associated with significantly lower odds of mortality ((OR, 0.6; 95%CI, 0.5-0.7; I2, 0%). No publication bias or heterogeneity was observed.

Conclusion
The use of follow-up blood cultures in patients with Gram-negative bacteremia was associated with lower mortality. Randomized controlled trials are needed. Currently, follow-up blood cultures should be obtained for at least the high-risk patients with Gram-negative bacteremia.

Disclosures
Khalid Eljaaly, PharmD, MS, BCPS, BCIDP, FCCP, Reckitt Benckiser Healthcare International Ltd, UK: Member of the Global Respiratory Infection Partnership, supported by unrestricted educational grant from Reckitt Benckiser Healthcare Ltd
191. When Staph Is Not Solo: Polymicrobial Methicillin-Resistant Staphylococcus aureus Bloodstream Infections
Authors: Escalona Angelica , Hayashi Emi , Evans Michelle , van Bakel Harm , Dupper Amy C , Alburquerque Bremy , McBride Russell B , Altman Deena 
Published: November 2023

Abstract

Background
Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a serious public health concern. At times, MRSA is isolated from the blood along with other pathogens, the significance and the consequences of which are not well described. This study aims to outline the clinical characteristics and outcomes of those with polymicrobial MRSA BSI compared with those with monomicrobial MRSA BSI.

Methods
We conducted a retrospective case-control study of those with and without polymicrobial MRSA BSI from 2014 to 2022 at a single quaternary care center in New York. Risk factors and outcomes for polymicrobial MRSA BSI were assessed using logistic regression analyses in SAS.

Results
Of 646 patients with MRSA BSI during the study period, 48 (7.4%) had polymicrobial MRSA BSI. In the univariate analysis, the presence of urinary device (p = 0.0174), and gastrointestinal device (p = 0.0287) were significantly associated with polymicrobial BSI. Polymicrobial BSI was associated with ICU admission after BSI (p = 0.0184). Mortality did not differ. Gram-positive Enterococcus sp. (22%) was the most common co-pathogen of MRSA in polymicrobial BSI.

Conclusion
While polymicrobial BSI remains relatively infrequent, risk factors for development may include devices in the genitourinary and gastrointestinal systems. Those who develop polymicrobial MRSA BSI may be at higher risk of being admitted to the ICU, signifying increased morbidity during hospital stay. Further studies are needed to evaluate the impact of polymicrobial MRSA BSI to elucidate the interplay between pathogens and the impact on infected hosts.

Disclosures
All Authors: No reported disclosures
194. Carbapenem Resistance Gene Detection in Positive Blood Cultures Reveals Emergence of NDM-Harboring Organisms and Associated Morbidity and Mortality
Authors: Haghamad Aya , Lemon Jamie , Duong Scott , Juretschko Stefan , Streva Vincent 
Published: November 2023

Abstract

Background
Blood stream infections caused by organisms harboring carbapenemase genes are a significant cause of morbidity and mortality. The prevalence of carbapenemase producing organisms (CPO) has been increasing for several years, with the majority of isolates originating in healthcare settings and containing one of the five most prevalent carbapenemase genes (KPC, OXA-48-like, NDM, VIM, IMP). Management of patients with CPO is particularly challenging and knowledge of the specific carbapenemase gene harbored by these organisms is informative for proper selection of antimicrobial therapy.

Methods
We conducted a retrospective multicenter study of hospitalized patients with blood cultures positive for CPO from January 2021 to present. We used blood culture PCR results to identify the most common carbapenemase genes associated with blood stream infections in our hospital system. Additionally, we evaluated these patients for clinical outcomes including length of hospital stay and mortality.

Results
A total of 61 CPO positive blood cultures from 10 hospitals were included in our study. There was an increase in CPO from 2021 (13 CPO) to 2022 (38 CPO). This increase is maintained year to date in 2023 (9 CPO in Q1) and was primarily driven by the emergence of NDM harboring CPOs in 2022 (19 cultures) continuing into 2023 (5 cultures in Q1). The predominant CPO isolated was Klebsiella pneumoniae (40/61, 66%). We observed an increasing trend across the study years in both length of hospital stay (18 days for 2021, 21 days for 2022, 35 days for 2023) and patient mortality (46% for 2021, 54% for 2022, 60% for 2023), though overall clinical outcomes were poor.

Conclusion
Our results suggest that the landscape of CPOs is evolving in the New York City area. Timely reporting and differentiation of carbapenem resistance genes is important to inform changes in antimicrobial therapy. Despite appropriate clinical intervention, mortality rates appear to be increasing for patients with CPO bloodstream infections, likely due to the emergence of NDM-harboring CPOs in 2022.

Disclosures
All Authors: No reported disclosures
200. Comparison of Clinical Outcomes among Patients Treated with Ceftriaxone 2 Grams versus 1 Gram Daily for Gram-Negative Bacteremia
Authors: Huynh-Phan Ricky , Zidaru Andrei , Phe Kady 
Published: November 2023

Abstract

Background
Ceftriaxone (CRO) is commonly utilized for the treatment of Gram-negative infections. However, there are limited data on the appropriate dose of CRO for the treatment of Gram-negative bacteremia. This study aimed to assess the clinical outcomes of CRO 2 grams versus 1 gram daily for Gram-negative bacteremia.

Methods
This was a retrospective, single-center study of patients with Gram-negative bacteremia that received CRO for ≥ 72 hours or over 50% of treatment duration as definitive treatment. Patients were excluded if they had polymicrobial bacteremia, had bacteremia with a Gram-negative organism that was resistant to CRO, or received empiric antibiotics other than CRO for ≥ 72 hours. Definitive treatment was defined as antibiotic utilized after the antibiotic susceptibility report was available to the clinician. Treatment failure was defined as antibiotic escalation due to clinical worsening at any time during CRO therapy. The primary endpoint for this study was 30-day hospital mortality. Secondary endpoints were treatment failure, readmission rates, and adverse reactions.

Results
Of 127 patients included, 57% received CRO 2 grams and 43% received 1 gram. The mean APACHE-II score did not differ between the 2 grams and 1 gram groups (13.8 ± 5.97 versus 12.5 ± 5.61, respectively; p = 0.238). Hypoalbuminemia was present in 21% of patients in the 2 grams group compared to 20% in the 1 gram group (p = 1.00). The most common Gram-negative bacteria isolated were Escherichia coli and Klebsiella species in 68% and 24% of patients, respectively. Hospital mortality in the entire cohort was 4% (n = 127). Patients receiving 2 grams had a numerically higher 30-day hospital mortality rate (7% versus 0%; p = 0.069). Patients receiving 2 grams also had numerically higher rates of treatment failure (15% versus 5%; p = 0.094). Readmission due to infection did not differ between groups (8% versus 5%; p = 0.731). Overall, ceftriaxone was well tolerated in both groups with no reported adverse reactions.

Conclusion
There was no significant difference in hospital mortality among patients treated with ceftriaxone 2 grams versus 1 gram for Gram-negative bacteremia.

Disclosures
All Authors: No reported disclosures
202. Association of Neutrophil - Lymphocyte Ratio with Bacteremia and In-Hospital Mortality in Sepsis Patients: A Retrospective Multicenter Study
Authors: Isha Shahin , Jonna Sadhana , Raavi Lekhya , Jenkins Anna , Hanson Abby J , Satashia Parthkumar , Yarrarapu Siva Naga S , Govero Austin , Harrison Michael F , Baig Hassan Z , Caples Sean M , Grek Ami A , Vizzini Michael R , Khan Syed A , Heise Katherine , Sekiguchi Hiroshi , Cantrell Warren , Smith Jeffrey D , Gnanapandithan Karthik , Thompson Kristine M , Graham Charles G , Cowdell Jed C , Murawska Baptista Aleksandra , Shapiro Anna B , Bhattacharyya Anirban , Chaudhary Sanjay , Kiley Sean , Guru Pramod K , Libertin Claudia , Moreno Franco Pablo , Sanghavi Devang K 
Published: November 2023

Abstract

Background
Early diagnosis, prognostication, and treatment initiation are the cornerstones of sepsis management. There remains an immense interest in exploring the diagnostic and prognostic roles of neutrophil-lymphocyte ratio (NLR) in the sepsis population.

Methods
We performed a retrospective multi-center observational study including patients admitted to different Mayo Clinic sites with a diagnosis of sepsis between October 2018 and August 2022. Patients were excluded if they were aged &lt; 18 years, lacked research authorization, or had missing Neutrophil or Lymphocyte count at admission. Data were collected from an existing sepsis database and Mayo Data Explorer (MDE). Categorical variables were summarized as percentages and continuous variables were summarized as medians. Chi-square test for significance, independent sample t-test, and multivariate Cox Proportional Hazard models were performed on IBM SPSS Statistics v28.0.

Results
Our study cohort consisted of 13968 patients, of which the majority were males (55.9%), Caucasian (91.6%), and non-Hispanic or Latino (94.3%). The median age of the cohort was 71 (60, 80) years, and the median BMI was 27.7 (23.4, 33.3) kg/m2.
Among all sepsis patients, 6.0% had a positive blood culture and the most common organisms were E. coli (26.5%), Klebsiella sp. (15.6%), Streptococcus sp. (12.8%) and Staphylococcus aureus (9.9%). 13131 patients (94.1%) survived the hospital stay and 837 (5.9%) did not. There was no difference in mortality based on blood culture positivity status (6.0% vs 6.6%, p=0.41).
However, the median NLR was higher among patients with a positive blood culture (16.4 vs. 12.1, p&lt; 0.001) and among non-survivors (14.3 vs 12.2, p&lt; 0.001). NLR did not significantly vary based on the type of organism growing in the blood culture. A multivariate model revealed NLR as an independent predictor of mortality (HR 1.003, 95% CI: 1.000-1.006, p=0.029) after adjusting for comorbidities, baseline clinical and laboratory variables. (Tables 1 & 2)

Conclusion
Our retrospective multicentric study showed that the Neutrophil-Lymphocyte ratio at admission was higher among bacteremic sepsis patients and non-survivors. Further prospective studies are needed to explore its diagnostic and prognostic utility.

Disclosures
All Authors: No reported disclosures
204. Clinical and Epidemiologic Review of Capnocytophaga Infections Identified at a Public Health Reference Laboratory – California, 2005 – 2021
Authors: Kelly Emily , Campagna Rebecca , Vugia Duc , Fritz Curtis L 
Published: November 2023

Abstract

Background
Capnocytophaga spp. are bacteria commonly found in the mouths of dogs and cats, which can infect people through bites or other contact with saliva. This study describes the epidemiology and clinical features of patients from whom Capnocytophaga spp. were isolated from clinical specimens at the California State Microbial Diseases Laboratory (MDL) over a 17-year period.

Methods
All MDL reports of Capnocytophaga spp. isolated from human patients between 2005 and 2021, including specimen submission forms and accompanying medical records, were reviewed. Data from these records were used to identify patients in datasets of statewide hospital patient discharge (PD) and emergency department (ED) admissions when possible. Clinical and other information in the PD and ED databases were used to confirm and supplement information from laboratory records.

Results
Capnocytophaga spp. were isolated in 48 specimens from 47 patients. The median age of patients was 68 years (range 12 to 88 years), and 57% were male. C. canimorsus represented 83% of the Capnocytophaga spp. identified. Capnocytophaga spp. were most frequently isolated from blood (88%), followed by cerebrospinal fluid (4%) and synovial fluid (4%). The most common case presentation was sepsis (45%), followed by skin and soft tissue infection (13%). Records for 45% of patients indicated at least one comorbidity associated with immunosuppression, including current malignancy (19%), diabetes mellitus (17%), alcohol use disorder (6%), and history of splenectomy (6%). Six records (13%) reported an animal bite (five dog bites, one cat bite).

Conclusion
This study documented Capnocytophaga spp. infection causing rare, severe disease in older and immunocompromised persons, often without report of an animal bite. This vulnerable group should be made aware of the risk of Capnocytophaga spp. infection from contact with cats and dogs and counseled to seek prompt medical care for any signs of infection, even if no known bite occurred.

Disclosures
All Authors: No reported disclosures
206. Prevalence of liver abscess in patients with Klebsiella pneumoniae bacteremia during a 5-year experience in a tertiary hospital in Thailand
Authors: Kiatkangwanchon Natthapol , Fujitnirun Chris 
Published: November 2023

Abstract

Background
The incidence of liver abscess in Thailand has increased in number nowadays.
K. pneumoniae is the most common cause of pyogenic liver abscess in the recent large series. Liver abscess can be a complication of K. pneumoniae bacteremic patients. We aimed to study the prevalence of liver abscess in patients with K. pneumoniae bacteremia and the comparison in clinical and laboratory characteristics of patients with K. pneumoniae between a group with liver abscess and the other without liver abscess.

Methods
This is a retrospective study; data were collected in Bhumibol Adulyadej Hospital among patients who were diagnosed with K. pneumoniae bacteremia between January 2014 – December 2019 and compared the difference in clinical and laboratory characteristics of patients between a group with liver abscess and the other without liver abscess.

Results
Of All 758 patients with K. pneumoniae bacteremia, 335 (44.19%) patients were done abdominal imaging, and 37 (4.9%) patients were found with liver abscess. The mean age was 65 years old, and most were male. Comorbidities were present in almost half of the patients including diabetes (118 patients, 35.22%), previous hepatobiliary surgery (21, 6.26%), and history of cancer (70, 20.90%). The other demographic data are shown in Table 1. Patients with liver abscess had diabetes (54.1% vs 29.3%, p-value = 0.082) and fever (91.89% vs 76.84%, p-value = 0.056) more than patients without abscess, however only 29.7% of patients with liver abscess had abdominal pain. Elevated transaminases above 2 times the upper limit of normal range are more frequent among patients with liver abscess than patients without abscess, for AST; 54.1%vs 35.30% (p-value = 0.026) and ALT; 40.5% vs 25.20% (p-value = 0.048). Clinical and laboratory characteristics are shown in Table 2.Table 1:Demographic data of patients with K. pneumoniae bacteremiaTable 2:Clinical and laboratory characteristics of patients with K. pneumoniae bacteremia

Conclusion
The prevalence of liver abscess in patients with K. pneumoniae bacteremia is 37 from 758 (4.9%). Liver abscess should be suspected in K. pneumoniae bacteremic patients who have elevated transaminases above 2 times the upper limit of normal range regardless of abdominal pain.

Disclosures
All Authors: No reported disclosures
227. Staphylococcus aureus bacteremia: back to normal
Authors: Pedromingo Kus Miguel Sebastian , Cristina Antolí Ana , Iglesias Núñez Nuria 
Published: November 2023

Abstract

Background
Staphylococcus aureus bacteremia (SAB) source is often unclear. One of the most common origins of SAB is cutaneous wounds and intravascular catheter-related bloodstream infection (CRBSI). Moreover, as our study group previously described, abscess formation and SAB following intramuscular injections are rare but possible complications from vaccines/inoculations. After an initial period of heightened SAB due to COVID-19 vaccines, we noticed a reversal of this circumstance.

Methods
In this case series, we present a cohort of 100 patients with SAB from January 1, 2021 through April 24, 2023, attended in our Institution (Hospital Nuestra Señora de Sonsoles, Ávila, Spain). We identified the SAB association with previous events, and the change in the recent paradigm of its genesis.

Results
During the study period, 100 SAB were identified. 85/100 patients were COVID-19 vaccinated. 64% were male and the rest were female. We identified the source of SAB in 90% of cases: in 12% (12/100) it clearly was a previously recent intramuscular vaccine (12/85 vaccinated patients; 14.1% of all COVID-19 vaccinated subjects). All-inclusive, the emergence of SAB was represented as follows: 24% from CRBSI, 23% from skin and soft tissue infections (SSTI), 11% - urinary tract infections (UTI), 10% - respiratory tract infections (RTI), 5% - endovascular reservoirs, 3% from postoperative complications in trauma surgery; septic mouth and bacterial parotiditis were responsible for one case (1% each). Finally, we were not able to identify 10% of the bacteremic fount. Overall, 54 patients died - 54% (46 deaths directly related to the SAB – 85.2%).

Conclusion
SAB always implies an outstanding risk due to its potential complications. Although we previously found an increased incidence of SAB related to COVID-19 vaccines, common causes such as CRBSI and SSTI, are now restored as usual sources. Nevertheless, mortality remains still high amongst our patients.

Disclosures
All Authors: No reported disclosures
245. Comparing Enterococcus faecalis and Enterococcus faecium Bloodstream Infections’ Severity and Mortality
Authors: Varghese Shawn , Sanders James , Monogue Marguerite , Yen Christina 
Published: November 2023

Abstract

Background
Enterococcus species commonly cause bloodstream infections (BSIs) with E. faecium infections considered especially worrisome due to association with vancomycin resistance via expression of the vanA gene. However, it is unclear if there is an association with E. faecium’s drug resistance potential and increased morbidity or mortality. Here we aimed to assess the severity of disease and mortality of patients with E. faecalis versus E. faecium BSIs, including subgroup analysis of vancomycin resistant E. faecium (VRE).

Methods
We conducted a retrospective, observational cohort study at a large urban academic center. Adult patients admitted from January 2018 to October 2022 with either E. faecalis or E. faecium BSI were included. Variables collected, determined a priori, included history of previous antibiotic use, malignancy, transplant status, and bacteremia source. Outcome variables of interest were ICU stay, length of stay, and mortality.

Results
There was a total of 182 total cases of E. faecalis and E. faecium BSI, 123 and 65, respectively, including 6 cases with both species (Table 1). Patients with E. faecium had higher median Pitt bacteremia scores (2 [IQR 0-4] versus 1 [IQR 0-3], p = 0.02) and longer median length of stay (30 [IQR 12-51] versus 15 [IQR 8-27], p &lt; 0.001). There was statistically higher all-cause mortality at time of data collection in the E. faecium (60% vs 41%, p = 0.01) and VRE cohorts compared with E. faecalis (63% vs. 41%, p = 0.02). Kaplan-Meier curve (Figure 1) demonstrates decreased survival in the E. faecium cohort compared to E. faecalis within the first 100 days after bacteremia (HR 1.84, p = 0.01). Of note, a difference in 90-day all cause mortality was only statistically different in the entire E. faecium cohort when compared to the E. faecalis cohort. (45% vs 29%, p = 0.04), in contrast to the VRE cohort (43% vs 29%, p = 0.12).
E. faecalis vs E. faecium results
Comparison of select variables
E. faecalis vs vancomycin resistant E. faecium results
Comparison of select variables

Conclusion
E. faecium BSIs appear associated with longer, more clinically severe hospital courses and significantly increased mortality, specifically 90-day mortality when compared to E. faecalis BSIs. Future inquiries should assess the extent to which E. faecium serves as an index versus driver of poor clinical outcomes and strategies to mitigate the associated mortality.

Disclosures
James Sanders, PhD, PharmD, Merck & Co., Inc.: Grant/Research Support|Shionogi Inc.: Grant/Research Support
246. A Retrospective Cohort Study Comparing Two Versus Three Blood Culture Sets in People Who Inject Drugs
Authors: Wang Aprilgate , Shih Michael C , Radosta Stella , Mushatt David 
Published: November 2023

Abstract

Background
The current standard of drawing two versus three sets of blood cultures lacks adequate guidance. Because people who inject drugs (PWID) are at higher risk for bacteremia and life-threatening illness, risk-benefit analysis become especially unclear.

Methods
We conducted a retrospective cohort study of PWID who had blood cultures drawn between 2017 and 2022 at a single multihospital system. Data was extracted and analyzed to determine (a) the rates of bacteremia for two versus three sets of blood cultures, (b) rates of false positive (contaminants) for two versus three sets of blood cultures, and (c) the downstream effects from contaminant growths. Exclusion criteria were blood cultures obtained greater than four hours apart, blood cultures obtained after antibiotic administration, and subsequent blood cultures obtained during the same hospitalization.

Results
998 PWID patients with 2278 sets of blood cultures were analyzed. There were 1618 cases with two blood culture sets and 660 cases with three. Potential benefit of adding a third blood culture set, indicated by 1 out of 3 containing pathogenic growth, was seen in 30 (4.5%) cases. However, only 13 (2.0%) cases showed true benefit, as 17 (2.6%) involved known inadequately treated infections or the same pathogen on another culture. The number needed to treat (NNT) was 51. By adding a third blood culture set, the relative risk of a contaminant increased by 39.7%; the number needed to harm (NNH) was 36. There were statistically more contaminants in three blood culture sets (65, 9.8%) than for two (114, 7.1%) (p&lt;0.00001). Out of 179 culture sets with only contaminants, 115 (64.2%) were analyzed for complications, which included 7 (6.14%) hospital readmissions, average 3.4 (SD 1.9) extra days of admission for 9 patients, average 1.3 (SD 1.2) extra blood cultures, total 13 (11.9%) extra microbial speciations, and average 2.3 (SD 1.9) days of unnecessary antibiotic administration for 27 patients.

Conclusion
Benefits of a third blood culture set do not universally outweigh risks for contaminant growth for PWID. A third blood culture set should be considered in specific clinical scenarios (i.e., inadequately treated endocarditis and osteomyelitis).

Disclosures
All Authors: No reported disclosures