bluuebunny/crossref_metadata_2025_split huggingface dataset:
698. Prevalence of Clostridioides difficile Infection in Patients with Isolated Glutamate Dehydrogenase (GDH) Positive
Authors: Pharnusopon Tanadhol , Chavapradit Natthakit 
Published: November 2023

Abstract

Background
Clostridioides difficile infection associated diarrhea is one of the world's health problems. The diagnosis method varies across guidelines. Nowadays, PCR for Clostridioides difficile is the standard modality in many institutions. But for resource-limited settings, a combination of GDH and Toxin A/B could be used. However, when an isolated positive GDH test with negative for toxin A/B, stool PCR should be done to confirm the diagnosis in highly suspected cases. This study aims to study the need for PCR testing by identifying the prevalence rate and specific characteristics associated with Clostridium difficile infection among isolated GDH-positive patients.

Methods
The prospective study collected data from patients who were admitted to Bhumibol Adulyadej Hospital, a tertiary hospital center in Bangkok, Thailand, from December 2021 to April 2023. The eligible criteria were patients over 18 years of age who were clinically suspected of Clostridioides difficile infection with stool GDH positive and toxin A/B negative. After informed consent, stool PCR for Clostridioides difficile was done, and patients characteristics, treatment, and outcomes were collected. The outcomes were to study the prevalence of Clostridioides difficile infection and identify characteristics among patients that helped predict the infection.

Results
There were 37 participants included in this study; 17 were male, and the median age was 63 years old. 5.4% of participants would be classified as having a fulminant Clostridioides difficile infection and 35.1% as having a severe infection if a PCR test was positive. The prevalence of PCR-confirmed Clostridioides difficile infection was 8 of 37 (21.6%). Factors that helped predict the infection included ICU admission (sensitivity 50%, specificity 79.3%), hypoalbuminemia (sensitivity 87.5%, specificity 10.3%), stool leukocytes (sensitivity 25%, specificity 65.5%), blood leukocytosis (sensitivity 37.5%, specificity 68.9%), and empirical treatment from a physician (sensitivity 50%, specificity 37.9%).

Conclusion
Among patients who have stool Clostridioides difficile GDH positive but Toxin A/B negative, even though the incidence rate of disease is low, stool PCR should be done in every case due to the lack of clinically specific characteristics.

Disclosures
All Authors: No reported disclosures
707. Molecular Epidemiology of Clostridioides difficile Colonization in Families with Infants
Authors: Toltzis Philip , Marlow Christine , Clayton Jason , Golonka Gregory , Maruskin Lynn , Jencson Annette , Choi Hosoon , Chatterjee Piyali , Whang Munok , Jinadatha Chetan , Cadnum Jennifer , Donskey Curtis 
Published: November 2023

Abstract

Background
We previously reported a high incidence of C. difficile colonization among parents caring for an asymptomatically-excreting infant (IDWeek 2022, Abs 2007), suggesting infants as a nidus of adult infection. Herein we define the molecular epidemiology of the organisms isolated within these families.

Methods
Families were enrolled at the baby’s 4-month well child visit at a suburban pediatric practice. Soiled diapers were mailed every two weeks for 4 months (total 8 time-point (TPs)) to a research laboratory. Stool was inoculated onto CDBA plates with portions broth- enriched. Simultaneously sent parental diaper wipes were handled identically. C. difficile was identified by colony morphology and GDH assay. Specimens from each family were assessed for relatedness by PCR ribotyping, and Whole Genome Sequencing (WGS) was utilized to determine genetic relatedness of repeatedly excreted organisms over time, both employing methods previously described (ICHE 2021;42:731).

Results
30 families (babies and mothers plus 22 fathers) participated, with 25 families submitting specimens at &gt; 4 TPs. Prevalence of infant colonization/TP ranged from 50-72%, and cumulatively 90% were positive at least once (median 4 samples positive/subject). Prevalence among mothers was 18-39%/TP (cumulative 87%, median 2 samples positive/subject) and fathers 20-41%/TP (cumulative 86% positive, median 1 sample positive/subject). In 27 families C. difficile was isolated from &gt; 1 member, with all but 1 including the infant. Isolates from 24 families could be ribotyped. In 6 families each member had a non-identical ribotype, in 3 families there was a single identical ribotype, and in 15 families some ribotypes were shared but &gt; 1 member harbored &gt; 1 ribotype. For example, one infant-mother pair shared two different ribotypes, but each harbored 1 additional distinct ribotype. WGS of persistently carried isolates with identical ribotypes from both infants and adults were related, usually exhibiting &lt; 3 SNP differences.

Conclusion
C difficile is prevalent in families caring for infants. Molecular analysis revealed a previously unrecognized complex epidemiology, with most family members sharing at least 1 common strain but frequently accompanied by additional unrelated ribotypes.

Disclosures
All Authors: No reported disclosures
714. Genotypic Resistance in Acinetobacter as a Predictor for Patient Outcomes
Authors: Jinadatha Chetan , Dhar Sorabh , Coppin John David , Navarathna Thanuri , Kaye Keith S , Choi Hosoon , Chatterjee Piyali 
Published: November 2023

Abstract

Background
Infections caused by Acinetobacter baumannii are frequently difficult to treat with currently available antibiotics. Oxacillinases (blaOXA-23), beta-lactamase (blaTEM-1D) are known to contribute to antibiotic resistance. The purpose of this study was to identify if resistance genes such as blaOXA-23 and/or blaTEM-1D contribute to adverse patient outcomes such as prolonged infection leading to increased duration of stay and mortality in hospitalized patients.

Methods
Clinical patient isolates were collected from two acute care hospitals, a 383-bed, and a 248-bed hospital in the Detroit metropolitan area. A total of 115 isolates samples and with complete clinical data sets were collected from 2 medical ICUs, 2 surgical ICU wards and 12 non-ICU surgical wards between 2017-2021. Resistance genes were analyzed using Resfinder (version 4.0) following whole genome sequencing (Illumina, NextSeq). Separate Bayesian regression models were used for the outcomes of interest: length of stay (LOS) and 30-day mortality, for each gene, blaOXA-23 and blaTEM-1D, as a predictor and adjusting for age and sex, using negative binomial models for LOS and logistic regression for mortality. Full models were fit to each outcome that included the interaction of both genes and adjusted for age, gender, hospital unit, respiratory infection, diabetes, COPD, hypertension, and renal dysfunction.

Results
The patient clinical characteristics between the resistant and susceptible Acinetobacter groups were matched (Table1). There was little evidence for the genes affecting either 30-day mortality or LOS for the full models. There was some evidence for increased odds of mortality with the presence of blaOXA-23, 0.75 (95% uncertainty interval: -0.06, 1.60), or both blaOXA-23 and blaTEM-1D, 0.85 (-0.2, 2.0) but not at the 95% level (Figure 1, Table 2). There was little evidence for an effect for the genes on LOS.

Conclusion
Although there was a trend towards resistance genes affecting outcomes, the full analysis indicated no relationship between resistance genes and overall outcomes. Other factors such as advanced age, and comorbidities may be contributing to the mortality. In the future, factors that contribute to adverse clinical outcomes using a larger cohort will be explored.

Disclosures
Keith S. Kaye, MD, MPH, Abbvie: Advisor/Consultant|Abbvie: Honoraria|Entasis: Advisor/Consultant|Entasis: Honoraria|GSK: Advisor/Consultant|GSK: Honoraria|Merck: Advisor/Consultant|Merck: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Honoraria|VenatoRx: Advisor/Consultant|VenatoRx: Honoraria
716. Effect of Carbapenem-resistant vs. Carbapenem-susceptible Enterobacterales infections on patient outcomes at an academic medical center
Authors: Clark Justin A , Burgess David , Moga Daniella 
Published: November 2023

Abstract

Background
Carbapenem-resistant Enterobacterales (CRE) infections have been shown to lead to excess mortality in patients. To estimate the impact of CRE at an academic medical center not in an endemic area for CRE infections, we sought to compare them against patients having infections by carbapenem-susceptible Enterobacterales (CSE).

Methods
This was a retrospective cohort study performed at UK Healthcare Medical Center which assessed admissions between January 1, 2010 – December 31, 2019. The index date was the first positive culture of E. coli, E. cloacae, K. aerogenes, K. oxytoca, and/or K. pneumoniae. Patients having a CRE culture on index were included in the exposure group, and those having all CSE cultures were included in the comparator group. Exclusion criteria were age &lt; 18 years old, pregnancy, endocarditis, osteomyelitis, necrotizing fasciitis, or cystic fibrosis. Outcomes of interest were 14- and 30-day composite of all-cause mortality or discharge to hospice with follow-up beginning from the index culture. Relative risk (RR) and hazard ratio (HR) were utilized to compare outcomes and inverse probability of treatment weighting (IPTW) was used for statistical adjustment.

Results
Across the decade, 128 patients were included in the CRE group and 6,953 in the CSE group. IPTW-adjusted RR and HR [95% CI] of composite outcome were 1.11 [0.7, 1.74] and 0.98 [0.61, 1.57] after 14 days and 1.19 [0.8, 1.77] and 0.99 [0.65, 1.51] after 30 days, respectively. When utilizing an exposure definition of carbapenem non-susceptible Enterobacterales (CNSE), the RR and HR were
1.11 [0.79, 1.57] and 0.95 [0.66, 1.36] after 14 days and 1.25 [0.93, 1.68] and 1.02 [0.75, 1.4] after 30 days. When using the non-susceptible exposure and only including patients with bloodstream infections on index, the RR and HR were 1.50 [0.93, 2.43] and 1.42 [0.85, 2.36] after 14 days and 1.48 [0.96, 2.29] and 1.38 [0.85, 2.24] after 30 days.

Conclusion
Although the composite outcomes between the CRE and CSE groups were not statistically significantly different, an increased risk appeared to exist in follow-up analysis. Continued efforts including observations across multiple institutions are needed to further characterize risks associated with CRE infections.

Disclosures
All Authors: No reported disclosures
718. Sulbactam Susceptibility Testing by Gradient Diffusion Method (E-test) in Carbapenem-Resistant Acinetobacter baumannii (CRAB) from a Tertiary Care Hospital in Thailand
Authors: Fujitnirun Chris , Dungdonbom Sariya , Rungnobhakhun Pimpha 
Published: November 2023

Abstract

Background
Introduction: CRAB is one of the major pathogens of nosocomial infection in Thailand and also cause a great burden to global public heath. Current treatments for CRAB are limited because of multidrug resistance and drug toxicity especially renal toxicity associated with colistin. ESCMID guidelines and IDSA guidance in 2021 recommended sulbactam as the first line treatment for sulbactam susceptible CRAB. Here we reported susceptibility data of CRAB to sulbactam in a tertiary care hospital in Thailand.

Methods
CRAB were isolated from from inpatients admitted to Bhumibol Adulyadej Hospital, a 600-bed tertiary government hospital in Bangkok, Thailand, from February to April 2023. The minimal inhibitory concentration (MIC) of sulbactam was determined by the gradient diffusion method (E-test strip, Qilu Antibiotics) using Mueller-Hinton agar plates and reported by an experienced clinical microbiologist.

Results
Among 27 isolates of CRAB, sputum is the most common source of the organism (70%) (figure 1). The MIC range of sulbactam was 8 to ≥ 256 μg/ml. Median MIC was 32 μg/ml but the most frequently reported MIC was ≥ 256 μg/ml (41%) and 89% of the isolates showed MIC ≥ 24 μg/ml as shown in figure 2.
Figure 1
Source of A. baumannii isolates
Figure 2
MIC of A. baumannii isolates

Conclusion
At the present time, there was only breakpoint for sulbactam in combination with ampicillin. Clinical breakpoint of sulbactam alone for A. baumannii was not defined by current documents of both CLSI and EUCAST. Current recommendations which suggest 9 g/day of sulbactam for CRAB infection based on data from “less susceptible” CRAB (sulbactam MIC &gt; 4 but ≤16 μg/ml). Our study reported isolates of CRAB that showed very high sulbactam MIC. These findings caution that local sulbactam susceptibility pattern should be defined before using sulbactam as the first line empirical treatment for CRAB infection.

Disclosures
All Authors: No reported disclosures
720. The clinical outcomes of hypervirulent carbapenem-resistant Klebsiella pneumoniae (CRKP) infection were not poorer than that of classical CRKP infection
Authors: Hu Ya , Zong Zhiyong 
Published: November 2023

Abstract

Background
Hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) was superbug for patients. Despite the high resistance and virulence, the clinical outcomes of hv-CRKP induced infections were not ever measured before.

Methods
We conducted a retrospective observational study of patients hospitalized at a comprehensive teaching hospital from July 2019 to June 2022 with CRKP being detected from their clinical samples. Isolates presenting resistance to meropenem and carrying carbapenemase-producing genes were deemed as CRKP. Hypervirulence was defined by the existence of iuc and/or either rmpA or rmpA2. Hv-CRKP met both conditions of CRKP and hypervirulence, and cCRKP met only the condition of CRKP but not hypervirulence. The corresponding patients were subsequently aligned into hv-CRKP group and cCRKP group, respectively (Figure 1). Outcome variables were compared between hv-CRKP group and classical CRKP (cCRKP) group.Figure 1.Screening workflow

Results
In total, 534 patients were identified and included in this study, wherein 42.7% were of hv-CRKP infection and 57.3% were of cCRKP infection (Table 1). The 30-day all-cause mortality was 32.4% overall. The 30-day all-cause mortality of cCRKP group was a bit higher than hv-CRKP group (33.7% vs. 30.7%, p=0.513). Within BSI group, the hv-CRKP group presented higher 30-day all-cause mortality than cCRKP group (8.8% vs.7.5%, p=0.792). The 30-day infection attributable mortality was 79.8%. The length of stay (LOS) of CRKP infection patients ranged from 0 day to 1318 days with a median of 34 days. Only a half day difference in the mean LOS was seen between hv-CRKP group and cCRKP group (p=0.769). The mean post-culture LOS of CRKP infection was 14 days ranging from 0 to 1154. Comparing to cCRKP group, hv-CRKP group had a two-day shorter median of post-culture LOS (p=0.244). The survival of CRKP infection was 122 days in median and ranged from 0 to 1260 days. Hv-CRKP group had a diminished mean survival as to cCRKP group (18 days vs. 25 days, p=0.167). Survival curve presented a similar effect of both groups (Figure 2, p=0.926).
Table 1-1
Table 1-1 Table 1-2
Table 1-2Figure 2.Kaplan-Meier curve for 30-day mortality

Conclusion
Patients with hv-CRKP and patients with cCRKP had similar clinical outcomes.The clinical outcomes of hv-CRKP infection were not poorer than that of cCRKP infection.

Disclosures
All Authors: No reported disclosures
723. Clinical and demographic features associated with isolation of ESBL-producing Enterobacteriaceae in a private hospital in Kingston, Jamaica
Authors: Liu Eugene W , Mendoza Matthew , Fletcher Hansel , Coombs Fredricka 
Published: November 2023

Abstract

Background
Emergence of antibiotic resistant bacteria is a public health threat. Data on the burden of ESBL-producing bacteria is limited, particularly in low to middle income countries, such as Jamaica. Here we sought to identify clinical and demographic features associated with extended spectrum β-lactamase producing Enterobacterales (ESBLs) in patients at Andrews Memorial Hospital (AMH), a private hospital in Kingston, Jamaica.

Methods
This retrospective case control study compared patients with cultures with and without ESBLs. Cases and controls were identified from 2021 microbiology records. Case subjects were AMH patients with ≥ 1 Enterobacterales isolate resistant to ceftriaxone, and controls were individuals without any ESBLs isolated on culture in 2021 with at least one culture (including ones without growth) performed the first week each month. We included all possible cases and performed stratified random sampling by month of controls to reach a 1:2 case:control ratio. We identified cultures of interest, defined as the first culture with an ESBL isolate for each case and the first culture from the random sample for each control. For each culture of interest, we extracted electronic medical record data including antibiotics received in the preceding 6 months, organism, sex, and age.

Results
Among 35 cases and 48 controls, age (1.04; 95%CI 1.01-1.06); male sex (5.46; 1.93-15.50); and isolation of Enterobacter species (10.93; 1.23-97.04) were associated with increased odds of ESBL isolation on simple logistic regression. Bidirectional stepwise variable selection indicated these associated factors should be included in a multiple logistic regression model. In this model, age (1.05; 1.00-1.09) and isolation of Enterobacter species (17.53; 1.39-220.76) were independently associated with increased odds of ESBL isolation.
Table 1
Risk Factors for Isolation of ESBL in AMH Patients, as Estimated with Simple Logistic Regression Models—2021​
Table 2
Medication Risk Factors for Isolation of ESBL in AMH Patients, as Estimated with Simple Logistic Regression Models—2021​

Conclusion
Age was independently associated with increased odds of ESBLs and may be a marker for past exposure to β-lactam antibiotics or nosocomial infection with ESBLs. Past exposures may have greater influence on ESBL isolation compared to receipt of antibiotics in the past 6 months where we saw no associations. The association with isolation of Enterobacter species and ESBL isolation may be from confounding with ampC inducible resistance.

Disclosures
All Authors: No reported disclosures
724. Prevalence and Risk Factors for Carbapenem Resistant Enterobacterales Colonization on Admission to Two Intensive Care Units in India
Authors: Mansoor Armaghan-e-Rehman , Edathadathil Fabia , Suresh Devendhu , Krishna Yathu , George Anu , van Rheenen Jacaranda , Sinclair Dorothy , Olsen Margaret A , Vasudevan Anil K , Kwon Jennie H , Leekha Surbhi , Singh Sanjeev , Warren David K , Gandra Sumanth 
Published: November 2023

Abstract

Background
Carbapenem-resistant Enterobacterales (CRE) infections are endemic in Indian hospitals however, studies examining intestinal colonization of CRE on admission to intensive care units (ICUs) are very limited. This study examines the prevalence and risk factors for CRE colonization on admission to two ICUs in a tertiary-care hospital in India.

Methods
Peri-rectal swabs were collected from consented patients prospectively enrolled between December 16, 2022 and March 31, 2023 in the medical ICU (MICU) and surgical ICU (SICU). Swabs were plated on selective agar (CHROMagarTMmSuperCARBATM) within 24 hours of collection for CRE isolation. Identification and susceptibility of presumed CRE isolates were confirmed by VITEK2. The modified carbapenem inactivation (mCIM) test and the EDTA carbapenem inactivation method (eCIM) were used to assess carbapenemase production. Information on CRE colonization risk factors (hospitalization and ICU stay in last one year, transfer from outside hospital, long-term hemodialysis) was collected.

Results
A total of 453 patients were admitted to both ICUs during the study period and 158 patients gave consent. Overall CRE prevalence among 158 patients was 54% (86/158). Peri-rectal swab was obtained within 48 hours of admission for 78 patients (Figure 1), and CRE prevalence in this cohort was 42% [33/78], with significantly higher prevalence noted among patients in the MICU compared to SICU (63% [17/27] vs 31% [16/51], p=0.007). Hospitalization, or ICU admission within the last 1 year, and long-term dialysis were significantly associated with CRE colonization (Table 1).
Among 33 patients with CRE colonization on admission, the most common CRE isolated was Klebsiella pneumoniae (59% [20/34 isolates]) followed by Escherichia coli (38% [13/34 isolates]). Among the 34 CRE isolates, 19 were metallo-beta-lactamase producers and 15 were serine carbapenemase producers.

Table 1

Conclusion
High prevalence of CRE colonization on admission was observed in the two ICUs, with prior hospitalization significantly associated with CRE colonization. Significantly higher proportion of CRE colonization was seen in the MICU as compared to SICU. Future studies should examine the risk factors associated with CRE acquisition during hospitalization to design interventions.

Disclosures
All Authors: No reported disclosures
725. Characteristics and Risk Factors for Mortality in Patients with Infections Caused by Serratia marscescens in a Referral Hospital in Nicaragua
Authors: Mayorga Darwin Moisés , Marenco-Avilés Sunaya , Porras-Cortés Guillermo D 
Published: November 2023

Abstract

Background
Serratia marcescens is a relevant pathogen both for its ability to cause serious infections and for its resistance pattern. In Hospital Dr. Fernando Vélez Paiz (Nicaragua), S. marcescens is the second most frequent bacterium isolated in healthcare-associated infections. The aim of this study is to describe the epidemiology and characteristics associated with mortality in hospitalized patients with infections caused by this bacterium between January 2022 and December 2022.

Methods
This is a retrospective, analytical, and cross-sectional study. The universe consisted of 239 patients with documented infections and positive cultures for S. marcescens. A sample of 131 patients was obtained once the inclusion and exclusion criteria were applied (Figure 1). An analysis of survivors and non-survivors was performed to identify risk factors for mortality.Figure 1.Flowchart of Selection of Patients with Serratia marcescens Infection

Results
The mean age was 43.8 ± 17.1 years old, and 56.5% of the patients were female. At least one comorbidity was found in 53.4% of patients. The most common chronic conditions were diabetes (74.3%) and hypertension (58.5%). The most frequent sites of infection were surgical site (51.9%), skin and skin structure (24.4%), and bloodstream infection (10.7%) (Table 1). Of the 131 patients, 76 (58%) were categorized as having a healthcare-associated infection. The mortality rate was 15.3%. The non-survivors were older (56.5 ± 16.5 years old) than the survivors (41.6 ± 16.3 years old). The pneumonia was present in 15% of the non-survivors but only in 0.9% of the survivors. Extended-spectrum beta-lactamase (ESBL) production was detected in more than 80% of the strains of S. marcescens, and more than 50% were multidrug-resistant (Table 2). An analysis of multiple variables found factors associated with mortality such as: NEWS score ≥ 6 points [RM (95% CI): 84.0 (18.86-374.05)], cerebrovascular event and/or sequelae of this [RM (95% CI): 19.58 (1.92-199.3)], pneumonia [OR (95% CI): 19.41 (1.90-197.55)] among others (Table 3).

Conclusion
Serratia marcescens infections were mainly surgical site, and of skin and skin structure. Pneumonia was associated with a higher chance of death. Most strains were ESBL producers. Different factors were associated with mortality, including severity on the NEWS score at the time of diagnosis of the infection.

Disclosures
All Authors: No reported disclosures