bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-214. Primary Prophylaxis for Clostridioides difficile Infection in Lung Transplant Recipients: A Retrospective Study
Authors: Irwin Mark , Leedy Nicole , Nandavaram Sravanthi , Soria Jaime , Myint Thein 
Published: January 2025

Abstract

Background
There is a paucity of data supporting primary prophylaxis for Clostridioides difficile infection (CDI) in lung transplant recipients (LTRs). We aimed to determine if the incidence of CDI is reduced in LTRs receiving primary prophylaxis.
Table 1
Comparison of clinical characteristics of lung transplant recipients between the two groups.

Methods
A retrospective chart review of all lung transplants from January 2020 to May 2023 was conducted at our institution. CDI was defined as diarrhea with a positive PCR test for the toxin B gene. Primary prophylaxis for CDI at the time of lung transplantation was defined as any use of either oral vancomycin or oral metronidazole in an LTR who received broad-spectrum antibiotics without any history of prior CDI. The incidence of CDI in LTRs was compared between the group with primary prophylaxis and the group without prophylaxis.

Results
Of 92 eligible LTRs, 41 (44.6%) did not receive primary prophylaxis, and 51 (55.4%) received either oral vancomycin (n=45) or oral metronidazole (n=8). The median duration of primary prophylaxis was 23 days (Table1). The median duration of systemic antibiotics was 19 days in the prophylaxis group and 15 days in the no prophylaxis group (p=0.027). Clostridioides difficile testing was done in 55 (60.4%) patients within one year after lung transplantation. Three patients had CDI within three months, and one patient had CDI at eight months after lung transplantation.
The incidence of CDI within one year after lung transplantation was 8.1% (3/37) in the prophylaxis group compared to 5.6% (1/18) in the no prophylaxis group based on the Clostridioides difficile testing (p=0.60). The incidence would be lower if the LTRs who were not tested for Clostridioides difficile due to a lack of concern were included with those who tested negative. All-cause mortality was higher in the prophylaxis group compared to the no prophylaxis group (41.2% vs 19.5%; p=0.041).

Conclusion
Fifty-five percent of LTRs (51/92) received primary CDI prophylaxis, mainly oral vancomycin, at the time of lung transplantation. LTRs who required a longer duration of broad-spectrum antibiotics were more likely to receive primary prophylaxis. There was no difference in the incidence of CDI regardless of primary prophylaxis in LTRs. Our data do not support the use of primary prophylaxis in LTR to reduce incidence of CDI.

Disclosures
All Authors: No reported disclosures
P-222. Emergence and dissemination of Clostridioides difficile isolates with reduced fidaxomicin susceptibility in an acute care hospital
Authors: Redmond Sarah N , Cadnum Jennifer , Jencson Annette , Choi Hosoon , Hwang Munok , Chatterjee Piyali , Jinadatha Chetan , Donskey Curtis 
Published: January 2025

Abstract

Background
Despite increasing use of fidaxomicin for Clostridioides difficile infection (CDI), isolates with reduced susceptibility (minimum-inhibitory concentration [MIC] &gt;2 ug/mL) have been rare in surveillance studies. However, there has been recent reports of clinical isolates with reduced susceptibility associated with mutations in the RpoB and RpoC genes coding for the RNA polymerase target of fidaxomicin. The clinical implications of reduced susceptibility are uncertain because fidaxomicin achieves high concentrations in the intestinal tract.
Whole genome sequencing analysis demonstrating that isolates from 3 patients (patients 1, 3, and 4) infected with ribotype 097 strains (sequence type [ST] 21) are genetically related (&lt;2 single nucleotide polymorphism differences) suggesting patient-to-patient transmission
ST21 = Ribotype 097; ST2 = Ribotype 014-020

Methods
During a 3-year period, patients treated for CDI in an acute care hospital were assessed for recurrence and fidaxomicin treatment failure, defined as persistent symptoms and culture positivity after &gt;10 days of fidaxomicin treatment without an alternative explanation. Serial stool samples from these patients were cultured for C. difficile confirmed by MALDI-TOF. Susceptibility testing was performed by agar dilution. Whole genome sequencing (WGS) was performed to determine relatedness of the isolates (genetically related: &lt;2 single nucleotide polymorphism differences) and to identify mutations associated with reduced fidaxomicin susceptibility.

Results
Among 115 patients treated with fidaxomicin, there were 20 (17%) recurrences and 3 (2.6%) treatment failures. In 2 of the patients with treatment failure, initial C. difficile isolates were susceptible to fidaxomicin but genetically related isolates with reduced susceptibility (MIC &gt;16ug/mL) associated with distinct mutations in rpoB (V1143G) and rpoC (R89G) emerged. The patient with the rpoC mutation had recurrent hospital admissions and maintained carriage of the isolate with reduced susceptibility over a 3-year period. Three additional patients were infected with C. difficile isolates with fidaxomicin MICs &gt;8 ug/mL, including 2 patients with sequence type 21 (ribotype 097) isolates genetically related to the treatment failure isolate with the rpoC mutation (Figure).

Conclusion
Emergence of C. difficile isolates with reduced fidaxomicin susceptibility may play a role in some cases of fidaxomicin treatment failure. Our findings suggest that patient-to-patient transmission could lead to dissemination of isolates with reduced fidaxomicin susceptibility.

Disclosures
Curtis Donskey, MD, Clorox: Grant/Research Support|Pfizer: Grant/Research Support
P-237. The CLABSI (Central Line Audit by Staff Investigators) Intervention: Reducing Central Line Use in a Medical ICU using Physician-Led Prospective Audit and Feedback of Catheter Necessity
Authors: Dekitani Ken , Ben-Aderet Michael , Madhusudhan Meghan 
Published: January 2025

Abstract

Background
Prompt removal of unnecessary central lines has been associated with reduction in central line associated bloodstream infections (CLABSI). Following the COVID-19 pandemic, sustained increases in central line utilization and CLABSI were seen at our medical ICU (MICU). Here we present a quality improvement intervention of a weekly physician-led audit and feedback to reduce central line utilization.

Methods
The intervention was conducted in the MICU at a single tertiary-care hospital from June 2023 to February 2024. Once weekly, 2 physicians did an electronic medical record audit of all central lines. Line necessity was defined as requiring one or more of the following: irritant medication use, renal replacement therapy, hemodynamic monitoring, total parenteral nutrition, or inability to obtain peripheral access. Lines for renal replacement therapy (HD lines) were excluded from evaluation as they were medically necessary by definition. Once an unnecessary line was identified, the primary ICU fellow and attending were sent a text message prior to morning rounds to recommend removal. Central line removal rates and patient demographic data were collected from June 2023 to February 2024. Data on central line utilization and CLABSI rates were collected from July 2023 to December 2023 and compared to data from January 2022 to June 2023.

Results
365 patients and 447 central lines were reviewed. 49 (11%) central lines were deemed unnecessary and removal recommended, of which 26 (53%) were removed within 24 hours. The central line device utilization ratio (DUR) in line days per patient days decreased by 20%, from 0.48 to 0.38 [p = &lt; 0.0001]. When HD lines were included, we observed a reduction in DUR by 8%, from 0.61 to 0.56 [p = &lt; 0.0001]. The CLABSI National Healthcare Safety Network Standardized Infection Ratio (SIR) pre-implementation was 2.84 and post-implementation was 2.83 [p = 1.00].

Conclusion
A physician-led, once weekly prospective audit and feedback of central line necessity led to a substantial decline in central line utilization rates in our medical ICU. There was no observed reduction in CLABSI SIR, however this may be due to the short intervention period and low incidence rate of CLABSI; over time it would be expected that a reduction in central line days would lead to a reduction in CLABSI.

Disclosures
All Authors: No reported disclosures
P-261. Physician Attitude on Stethoscope Sanitization: A Quality Improvement Project
Authors: Chang Lin , White Cilian J 
Published: January 2025

Abstract

Background
Literature has demonstrated that stethoscopes can harbor pathogenic bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, vancomycin-resistant Enterococci and Clostridium difficile) and act as vectors of infection transmission between patients. Although it seems most healthcare professionals are aware of the potential of stethoscopes to transmit infections, the practice of stethoscope cleaning varies widely and is often not up to standard recommendations. This QI project aims to determine current stethoscope sanitization practices at our hospital, Morristown Medical Center (MMC), barriers that prevent more frequent cleaning, and whether education and easier access to sanitization methods changes practices of providers.
Figure 1: Frequency of stethoscope sanitization pre- and post-intervention

Methods
Participants (physicians at MMC) were asked to complete a pre- and post-intervention survey about their stethoscope cleaning practices and barriers to more frequent cleaning. Intervention consisted of physician education and placement of alcohol wipes at physician workspaces for 3 weeks.
Figure 2: Obstacles to stethoscope sanitization

Results
Of the 35 responses from the pre-intervention survey, 97% believed stethoscopes harbor harmful bacteria. 17% of physicians sanitized their stethoscopes after every patient encounter, 37% every day, 34% every week and 11.5% less than every week (Figure 1). Barriers to more frequent stethoscope cleaning included: inaccessibility of alcohol wipes (62.9%), difficult to remember (51.4%), too time-consuming (45.7%), and other (22.9%) (Figure 2). Post-intervention survey (25 responses) showed an increase from 17% to 48% for physicians that sanitize after every patient encounter. More importantly, 96% of participants agreed they would implement better stethoscope sanitization practices going forward.

Conclusion
Physicians are aware of the potential for stethoscopes to harbor bacteria and transmit infections, however, their stethoscope cleaning practices do not necessarily align with this knowledge, with only 17% sanitizing after every patient encounter. Allowing easier access to alcohol wipes as well as physician education served to increase frequency of stethoscope sanitization overall. Our conclusion is that ongoing education and reminders can help improve overall stethoscope sanitization practices in the hospital.

Disclosures
All Authors: No reported disclosures
P-270. Effects of Suppressed Susceptibilities on CRE Case Identification in Clinical Settings in Tennessee, 2016–2022
Authors: Daniel Lauren , Gambrell Ashley , Patel Dipen , Villegas Raquel , Muleta Daniel 
Published: January 2025

Abstract

Background
Carbapenem-resistant Enterobacterales (CRE) are multi-drug resistant organisms (MDRO) often spread in healthcare settings and reported as urgent public health threats by the Centers for Disease Control and Prevention (CDC). Antibiotic susceptibility testing (AST) is often performed, but some results get suppressed to encourage antibiotic stewardship. Tennessee participates in the Multi-site Gram-negative Surveillance Initiative (MuGSI) for CREs in Davidson and seven other surrounding counties. We evaluated the effect of suppression on the clinical identification of CREs in Tennessee.

Methods
Cases reported to MuGSI from 2016­–2022 were analyzed for case determination differences based on AST result interpretations between laboratory reports obtained from instrument and laboratory reports in the medical record. A CRE case was defined as E. coli, Enterobacter cloacae complex, or Klebsiella species resistant to one or more carbapenems and isolated from urine or a normally sterile site, from a resident of the catchment area. Doripenem is excluded from the susceptibility panel in most facilities, and thus not included in analysis. Data analysis was performed using SAS Version 9.4

Results
From 2016–2022 there were 570 cases of CRE, 32% male, 68% female and a mean age of 66 years. Among 570 reported cases, 407 (∼71%) were found to meet the case definition in both the reports obtained from laboratory instrument and reports in medical records. The remaining 163 (∼29%) of cases were found to be CRE based on reports from laboratory instrument but had no AST results for the carbapenems for clinicians in the medical record. The most suppressed carbapenem was imipenem (387), followed by ertapenem (148), and meropenem (119).

Conclusion
Approximately 29% of CRE cases in our data had AST result suppressed or a lack of AST results available in the medical record. Although lack of complete AST results does not preclude the clinician being aware of CRE status, it may result in additional difficulty treating a pathogen with few treatment options. Suppression can lead to better antibiotic stewardship, but MDROs often have complex treatment requirements with high morbidity and mortality for patients. More research is needed to determine the value of suppression as it relates to CREs and MDROs.

Disclosures
All Authors: No reported disclosures
P-278. Emerging Threat: Rising Incidence and Antimicrobial Resistance of Serratia marcescens in a Guatemalan Intensive Care Unit
Authors: Barrios Andrea , Elisa Rosales Ana , Orozco Jarleny , Pezzarossi Franco , Valenzuela Laura , Rodriguez Luis , Erdmenger Diego 
Published: January 2025

Abstract

Background
Serratia marcescen, a gram-negative bacillus, is an important pathogen associated with hospital acquired infections. It ranks as the 5thmost common Gram-negative organism in Intensive Care Units infections globally. With a global case-mortality of 2.8%, Serratia marcescens poses a substantial threat to healthcare systems.
The use of broad-spectrum antibiotics has led to increased antimicrobial resistance among Serratia strains. Rates of ESBL-producing isolates of Serratia have been reported ranging from 6-24% of all strains, in low- and middle-income countries.
This study evaluates the incidence and resistance patterns of Serratia isolates in Guatemala City.

Methods
An ecological study was conducted at an intensive care unit from a third-level reference hospital in Guatemala City from 2022 to 2023. All microbiologic isolates of Serratia Marcescens were included, and antimicrobial resistance was determined through the use VITEK® MS (Maldi Tof) and VITEK® 2 systems. Antimicrobial resistance patterns were identified according to the Clinical and Laboratory Standard Institute (CLSI) guidelines. GyrA/ParC phenotype was inferred through resistance to fluoroquinolones.

Results
A total of 20 isolates of Serratia were identified in 2022 and 49 in 2023. The majority of strains were isolated from respiratory samples (81.15%). There was a significant increase in Serratia positivity rates (4.72 vs 9.06 per 1000 cultures) and incidence of Serratia isolates (24.75 vs. 94.59 per 1000 admissions) from 2022 to 2023.
An increase in antimicrobial resistance was observed between 2022 and 2023. In 2022, 70% of strains where susceptible, and 20% showed only one mechanism of resistance. Conversely, in 2023, only 6% of strains where susceptible and over 57% presented more than one mechanism of resistance. An increase in inferred GyrA/ParC (5% vs 83.6%) and confirmed ESBL (0% vs 36.7%) phenotypes were observed.

Conclusion
An increased use of antimicrobials in the ICU may be associated with the sudden and alarming rise in resistance in Serratia isolates. The clinical impact of these ecological changes is yet to be determined.
The escalating incidence and resistance of S. marcescen in Guatemala City highlights the urgency for enhanced surveillance and antimicrobial stewardship programs.

Disclosures
All Authors: No reported disclosures
P-279. An Online Registry of Carbapenemase Producing Gram Negative Organisms for Evaluating the Clinical Profile, Outcomes and Mechanisms of Resistance in Two Tertiary Level Hospitals (ORiGiN Study): An Interim Analysis
Authors: Espino Adrian Ronald A , Alombro Danice Faith B , Ong Justin Allister G , Valdez Christel M , Joy Daguit Shanaia Esthelle , Ombao Daniel Jose N , Macalalad Lawrence S , Carascal Mark , Agnew Cajucom Marc , Flor Malundo Anna , Abad Cybele Lara R 
Published: January 2025

Abstract

Background
Infections with gram-negative carbapenem-resistant organisms (CRO) are an emerging global problem, but little is known about CRO in the Philippines. This study aims to build a registry and describe the clinical profile and molecular mechanisms of resistance of carbapenem-resistant infections.

Methods
This prospective study will enroll patients from two tertiary-level hospitals from 01/01/2023 to 12/31/2025. Admitted patients &gt;18 years old with documented CRO infection confirmed by phenotypic resistance and molecular testing are included in this year-1 analysis.

Results
150 patients were enrolled in the first year. Around half (79/150, 54.7%) were female. Median age was 60 (range 21-94) years. Many had at least one comorbidity -- hypertension (90/150 65.2%), diabetes mellitus (45/150, 32.6%), and congestive heart failure (42/150, 30.4%). Most patients experienced CR infection only once (123/150, 82%), while a few (27/150,18%) had two or more. Infections originated from respiratory (63.3%), blood (22.6%), or urinary (16.4%) sites. Higher mortality was seen among patients who received three or more antibiotics (119/150, 57.1%) or had prolonged treatment ( &gt;15 days) during admission (53.1%). Resistance to fluoroquinolones (ORadjusted=4.32 (95% CI: 1.11, 16.81); p=0.035) and older tetracyclines (ORadjusted=5.49 (95% CI: 1.08, 27.93); p=0.040) were significantly associated with mortality in the adjusted models. Only 9 out of 169 (5.32%) were Extended Spectrum Beta Lactamase (ESBL) producing. 40/169 (23.7%) were tested for carbapenem resistance genes and the two most common antimicrobial resistance genes were blandm (n= 17) and blaoxa51 (n=20).

Conclusion
The study provides initial data on the local epidemiology and molecular mechanisms of resistance of gram-negative CRO. Interim results show that CR infections affect the older population and are mainly respiratory in origin. Multiple antibiotics, prolonged therapy, and the use of fluoroquinolones and tetracyclines were all associated with higher mortality. Class D (OXA-51) and Class B (NDM) beta-lactamases were most frequently isolated.

Disclosures
All Authors: No reported disclosures
P-280. Risk Factors for Household Colonization with Extended-Spectrum Cephalosporin-Resistant Enterobacterales (ESCrE) in Botswana
Authors: Shivji Sukaina , Mannathoko Naledi , Mosepele Mosepele , Mosepele Mosepele , Gross Robert , Cressman Leigh , Jaskowiak Anne , Bilker Warren B , Alby Kevin , Glaser Laurel , Greenblatt Melissa , Cowden Laura , Patel Alexa , Sewawa Kgotlaetsile , Otukile Dimpho , Paganotti Giacomo , Mokomane Margaret , Snitkin Evan , Lautenbach Ebbing 
Published: January 2025

Abstract

Background
The epidemiology of colonization with ESCrE in the community in low- and middle-income countries (LMICs) is largely uncharacterized. In the community, the household is of particular importance as it is the setting in which individuals spend a majority of their time. Identifying risk factors for household ESCrE colonization is critical to inform antibiotic resistance reduction strategies in LMICs.

Methods
Participants were enrolled from 1/1/20-9/4/20, with a pause 4/2/20-5/21/20 due to a country-wide COVID lockdown. This study was conducted in 6 clinics located in 3 regions in Botswana. In each clinic, we surveyed a random sample of outpatients presenting for care. We also invited each enrolled subject to refer household members. Only those subjects who referred at least one other household member were included. All participants had rectal swabs collected for identification of ESCrE. Data were collected on demographics, comorbidities, antibiotic use, healthcare exposures, travel, and farm/animal contact. Households were considered exposed if any member had the exposure of interest. Households with ESCrE colonization (cases) were compared to non-colonized households (controls). Bivariable and multivariable analyses were conducted to identify risk factors for household ESCrE colonization.

Results
327 households were enrolled. The median (IQR) number of people enrolled per household was 3 (2-4) ranging from 2-10. Among enrolled households, the median proportion of household residents participating was 0.71 (0.5 – 1). The median (IQR) age of subjects was 18 years (5-34) and 304 (93%) households included at least one child. Of 327 households, 176 (54%) had at least one household member colonized with ESCrE. Independent risk factors for household colonization are noted in the table.

Conclusion
ESCrE household colonization was common with evidence of geographic variability in ESCrE epidemiology as well as a possible role of animal exposure. The role of yogurt exposure requires additional study as we did not distinguish source (commercial, homemade). Further prospective studies of household ESCrE colonization with longitudinal assessments of exposures are required to identify effective prevention strategies.

Disclosures
Robert Gross, MD, MSCE, Pfizer Inc: DSMB member for drug unrelated to study