Vancomycin-resistant Enterococci Colonization Research Articles

Management of vancomycin-resistant Enterococci and daptomycin-resistant Enterococci infections in liver transplant recipients in a single academic center.

Vancomycin-resistant Enterococci (VRE) infections cause significant morbidity and mortality in liver transplant (LT) recipients. Management is challenging, especially in the setting of daptomycin resistance (DR). Single-center retrospective review of patients who underwent LT between January 1, 2020, and December 31, 2022, and developed VRE infections. Descriptive statistics were used and Kaplan-Meier curves estimated freedom from treatment failure and survival. Forty-two patients (median age 58; 64% female; 67% white) were included. Alcohol-related cirrhosis (48%) and metabolic dysfunction-associated steatohepatitis (31%) were the most common indications for LT, and most were from deceased donors (86%). VRE infection occurred at a median of 21 days after LT, and 16% had known prior VRE colonization. Common infection sites were blood (45%, n = 19), intraabdominal (36%, n = 15), and urine (36%, n = 15). Most were initially treated with daptomycin alone (64%) or in combination with other agents (21%); 7% received linezolid alone. Twelve (29%) developed breakthrough infections during treatment and 11 (26%) had recurrent infections after discontinuation of treatment. All-cause mortality was 36% (n = 15) at a median of 90 days after VRE infection diagnosis and was nearly twice as high in patients with DR (63%). VRE infection in LT recipients relapsed or recurred in over 25%. Mortality was high, especially in cases with DR. More data is needed to establish an optimal treatment approach, particularly for relapse and DR.

Risk Factors for Colonization of Vancomycin-Resistant Enterococci in Patients in the Intensive Care Unit: A single-center Retrospective Study

Background: Patients colonised with vancomycin-resistant enterococci (VRE) remain a problem worldwide, especially in intensive care units (ICU), necessitating the identification of associated risk factors. Understanding these factors is crucial for implementing effective infection control measures. The aim of this single-centre retrospective study was to determine the risk factors for VRE colonisation in patients admitted to medical and surgical ICUs. Methods: We analyzed data from 190 patients admitted to the ICUs between January 2020 and December 2022. Demographic information, clinical characteristics, laboratory results, antimicrobial usage, and comorbidities were obtained from digital patient records. Rectal swabs were collected weekly within 48 hours of ICU admission to detect VRE colonization. Independent risk factors causing VRE colonisation were determined by logistic regression analyses. Results: Out of 190 patients, 54 were colonized with VRE. Significant independent risk factors for VRE colonization included higher APACHE II scores on ICU admission (OR: 1.26, 95% CI: 1.03-1.55, p=0.024), longer hospital stay (OR: 1.25, 95% CI: 1.14-1.36, p

Timesavers: Clinical Decision Support and Automation of MRSA and VRE Deisolation

Background: Most healthcare facilities in the US apply contact precautions (CP) for patients with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) infection and/or colonization. Most individuals with MRSA or VRE colonization will clear over time; however, frontline clinicians rarely evaluate for discontinuation of CP, resulting in increased burden on infection preventionists (IPs). Automation of time- and test-based evaluation using clinical decision support systems (CDSS) embedded in electronic health records (EHR) may increase evaluation and discontinuation of CP when appropriate, while preserving IP resources. Methods: This quality improvement initiative was implemented at Mass General Brigham (MGB), an integrated healthcare system, where patients with MRSA or VRE infection/colonization are identified in the EHR with a corresponding “infection status” and CP applied. Following MGB policy (Figure 1), CDSS features included: 1) automated time-based resolution from 2/15/2023-11/13/2023 and 2) automated ordering of screening assays for patients eligible for test-based evaluation from 6/20/2023-11/14/2023 (Figure 2). Counts of CP discontinuation and automated ordering were performed. IPs at one MGB facility performing manual review of patients self-recorded the time spent evaluating for CP discontinuation. Using these time reports, the average time to complete these tasks and the projected time savings were calculated over the implementation period. Results: Four IPs recorded the time to review patients for CP discontinuation, including reviewing recent antimicrobial administration, microbiology results, ordering screening test(s), and contacting the primary team. Twenty-five patient encounters were timed with a mean of 4.7 minutes documented per encounter. Over a 9-month period after initiation of the automated time-based resolution, the monthly mean number of patients with CP for MRSA and VRE which were automatically discontinued was 247 and 100, respectively. Projected IP time savings over the same 9-month period for MRSA and VRE were 174.1 and 70.5 hours, respectively. Over a 5-month period after initiation of automated ordering of MRSA polymerase chain reaction (PCR)/culture, as well as VRE culture for test-based evaluation, the monthly mean number of MRSA culture, MRSA PCR, and VRE culture automatically ordered for patients on CP for MRSA and VRE were 176, 24, and 145, respectively. Projected IP time savings over the same 5-month period for MRSA and VRE were 78.3 and 56.8 hours, respectively.Conclusion: Healthcare systems that enhance their EHR with CDSS to automate CP evaluations may improve frontline clinician workflow, patient flow and bed capacity, while optimizing use of IP resources.

Mechanisms of acquisition of the vanA operon among vancomycin-resistant Staphylococcus aureus genomes: The tip of the iceberg?

BackgroundVancomycin is frequently used as a last line of defence against infections due to multidrug-resistant Staphylococcus aureus (S. aureus). A recent finding described the acquisition of vancomycin-resistant S. aureus strains by the integration of an enterococcal plasmid containing the vanA operon into the S. aureus chromosome via homologous recombination involving a specific integration site called locus L2. MethodsTo characterise all mechanisms of acquisition of vanA, this study analysed the 15 706 S. aureus genomes to look for vanA and described its genetic environment. ResultsA complete vanA operon was found in 25 S. aureus strains isolated from 12 patients, including nine co-isolated with vancomycin-resistant Enterococcus strains. VanA was found within transposon Tn1546-like elements on 17 plasmids and eight chromosomes. VanA might be acquired through conjugation of enterococcal and staphylococcal plasmids, transposition of Tn1546 carrying vanA and plasmid integration into the chromosome. Further, L2 was detected in 2087 genomes (13.3%) of S. aureus strains across different continents. Six potential chromosomal hotspots for integration of the entire vanA-containing enterococcal plasmid were identified by homologous recombination via L2. ConclusionsThese findings suggest that the recently described scenario in a New York patient could be reproduced anywhere. Surveillance of this possibility is mandatory, especially in patients with vancomycin-resistant Enterococcus infection or colonisation.

Nutritional Strategies To Improve VRE Control

The rise of Vancomycin-resistant enterococci (VRE) strains among cellular therapy recipients raises concerns due to increased morbidity, mortality, and hospitalization costs, particularly impacting transplanted patients with diminished survival expectations. Recent research linking lactose to Enterococcus growth and graft-versus-host disease (GVHD) emphasizes the need for data on reducing lactose in the diets of VRE-carrying patients, especially in cellular therapy contexts like CAR-T or allogeneic hematopoietic stem cell transplantation. Responding to elevated VRE positivity rates in rectal swabs among patients in our BMT Unit, a unique nutritional strategy was implemented, introducing lactose-free milk and strictly enforcing lactose-free diets. This approach resulted in a significant reduction in VRE carriers, with a 16% positivity rate in the Lactose Group versus 3.6% in the Lactose-Free Group, as of June 2023. These results indicate the potential efficacy of this innovative nutritional strategy in high-risk departments, such as BMT Units and Intensive Care Units, with implications for reducing isolation strategies and inappropriate antibiotic use in cases of VRE colonization.

Uropathogenic distribution and antibiotic resistance patterns according to multidrug-resistant bacteria colonization status in patients with stroke.

Urinary tract infections (UTI) are common in patients with stroke. The colonization of multidrug-resistant organisms (MDR) has recently become a global issue, and infection with MDR is associated with a poorer prognosis. This study aimed to investigate the uropathogenic distribution in stroke patients according to MDR colonization and investigate the infection risk and antibiotic resistance of each uropathogen to help determine initial antibiotic treatment. This study is a retrospective study conducted on patients who underwent inpatient treatment for stroke at Kosin University Gospel Hospital in 2019 to 2021. The participants were classified into Group VRE if vancomycin-resistant Enterococcus (VRE) colonization was confirmed, Group CRE if carbapenem-resistant Enterobacteriaceae (CRE) colonization was confirmed, and Group Negative if no MDR colonization was confirmed. Urine culture was performed if symptomatic UTI was suspected. Uropathogenic distribution, antibiotic resistance patterns were assessed by one-way analysis of variance, independent t-test, and Pearson chi-square test. And the infection risk factors for each uropathogen were assessed by multinomial logistic regression analysis. Six hundred thirty-three participants were enrolled. The mean age of all participants was 69.77 ± 14.91, with 305 males and 328 females, including 344 hemorrhagic strokes and 289 ischemic strokes. No growth in urine culture was the most common finding (n = 281), followed by Escherichia coli (E.coli) (n = 141), and Enterococcus spp. (n = 80). Group Negative had significantly more cases of no growth in urine culture than Group VRE (Odds ratio [OR], 11.698; 95% confidence interval [CI], 3.566-38.375; P < .001) and than Group CRE (OR, 11.381; 95% CI, 2.665-48.611; P < .001). Group VRE had significantly more E.coli (OR, 2.905; 95% CI, 1.505-5.618; P = .001), and more Enterococcus (OR, 4.550; 95% CI, 2.253-9.187; P < .001) than Group Negative. There was no statistical difference in antibiotic resistance according to MDR colonization in E coli, but for Enterococcus spp., Group VRE and CRE showed significantly more resistance to numerous antibiotics than Group Negative. MDR colonization increases the risk of UTI and is associated with greater antibiotic resistance. For appropriate administration of antibiotics in UTI, continuous monitoring of the latest trends in uropathogenic distribution is required, and clinicians should pay more attention to the use of initial empirical antibiotics in patients with MDR colonization.

High Gastrointestinal Colonization Rate of Vancomycin-Resistant Enterococci among Hospitalized Patients: Potential Source for Resistant Gene.

Vancomycin-resistant Enterococci (VRE) is a global health problem and responsible for healthcare-associated infections (HAIs) in patients with prolonged hospital stay, severe underlying disease, and previous broad-spectrum antibiotic therapy. These bacteria can cross-resist and transfer drug-resistant genes to other potentially pathogenic bacteria. Therefore; this study was aimed to determine the gastrointestinal colonization rate of VRE, its antimicrobial susceptibility profile, and associated factors among hospitalized patients. Prospective cross-sectional study was conducted using stool samples from 223 patients admitted to different wards at Hawassa University Comprehensive Specialized Hospital, from April 1 to June 30, 2021. Patients admitted to the hospital for more than 48 hours for various medical conditions were included. Sociodemographic and clinical characteristics were collected using a structured questionnaire. Fecal specimens were cultured on Enterococci selective media. Enterococcus species were identified using their growth and mannitol fermentation properties. Vancomycin resistance was screened using both the Kirby-Bauer disk diffusion method and a vancomycin E-test strip. Data were entered and analyzed using SPSS version 25. Descriptive and logistic regressions were used to determine the frequency and association of factors with the VRE colonization rate. A p value of <0.05 was considered statistically significant. A total of 223 fecal specimens were collected and processed, and 141 (63.2%) them were positive for Enterococci. The predominant species was E. faecalis 65 (46.1%) followed by E. faecium 76 (53.9%). In this study, the gastrointestinal colonization rate of VRE was 15 (6.7%) and all the species belong to E. faecium. Study participants who had no formal education (AOR = 4.26, 95% CI: 1.01, 18.06), hospitalized patients for >2 weeks (AOR = 4.10, 95% CI: 1.08, 15.57), and those who had a history of treatment with vancomycin (AOR = 4.77, 95% CI: 1.26, 18.09) were more likely to be colonized with vancomycin-resistant Enterococci. More than 95% of Enterococci isolates were susceptible to linezolid, whereas 70.2%, 63.1%, 56.7%, and 53.9% were resistant to tetracycline, erythromycin, penicillin, and ampicillin, respectively. Among the total Enterococci isolated, 141 (54.6%) were multidrug resistant. In our study, high proportion of vancomycin-resistant Enterococci was found. Previous exposure to antibiotics and hospital stay were significant factors for VRE gut colonization. The isolated Enterococci showed variable degrees of resistance to commonly prescribed antibiotics which leads to a worldwide problem multidrug resistance. Therefore, periodic surveillance on antimicrobial resistance pattern, adhering to rational use of antibiotics, and implementing infection prevention protocols may reduce colonization by VRE.

712. Dynamics of Colonization with Multi-Drug Resistant Organisms and Clinical Outcomes in Critically Ill Patients: A Prospective Cohort Study

Abstract Background Critically ill patients have frequent intestinal colonization with multi-drug resistant organisms (MDRO). However, the duration of colonization and its impact on clinical outcomes are unknown. Methods We performed a prospective cohort study of adult patients admitted to ICUs at a tertiary care hospital. All patients had stool samples collected twice weekly for up to four weeks or until discharge from the ICU. Stool samples were cultured with selective media for vancomycin-resistant enterococci (VRE), extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E), and carbapenem-resistant Enterobacterales (CRE). We characterized patient demographics and compared outcomes between patients with and without colonization. Results A total of 102 patients were included. Mean age was 62 years (SD±15), 62 (61%) were men, 67 (66%) were white, and 34 (33%) were admitted from a separate healthcare facility. Thirty-nine (38%) were colonized with ≥1 MDRO at ≥1 time point. There were no statistically significant differences in baseline characteristics between patients with and without colonization. Of the 39 patients with colonization, 23 (59%) were colonized with VRE at ≥1 time point, 18 (46%) with ESBL-E, and 7 (18%) with CRE; 8 (20%) were colonized with &amp;gt;1 organism (Figure 1). Notably, most patients (13/23 with VRE, 15/18 with ESBL-E, and 4/7 with CRE colonization) were colonized with each MDRO type at only one time point during their ICU stay (Figure 1). In-hospital mortality did not differ according to colonization status (21% with any colonization vs. 17% without, p=0.70). When assessing mortality according to specific MDRO type, VRE colonization was associated with in-hospital mortality (35% with VRE colonization vs. 14% without, p=0.02). Figure 1. Results of serial stool samples tested for target multi-drug resistant organisms in intensive care unit patients. Each horizontal line represents a different patient included in the study (N=102) and each circle represents a separate stool sample. Conclusion Nearly 40% of ICU patients were colonized with VRE, ESBL-E, and/or CRE, although colonization duration was generally limited, possibly reflecting antibiotic pressures and microbiome dynamics in critically ill patients. More research is needed to identify clinical, microbiome, and organism genomic factors that facilitate persistence and loss of colonization. Disclosures All Authors: No reported disclosures

286. The Effect of Fecal Microbiota Transplantation on Decolonization of Multidrug-resistant Organisms in the gut

Abstract Background Gut colonization of multidrug-resistant organisms (MDROs), such as carbapenemase-producing Enterobacteriaceae (CPE) and vancomycin-resistant Enterococci (VRE), precedes clinical infections. It increases the risk of patient-to-patient transmission of MDROs as well as clinical infections such as bacteremia. Therefore, decolonization of MDROs in the gut by restoring colonization resistance through fecal microbiota transplantation (FMT) could be an effective infection control strategy for MDROs. Methods From March 2019 to November 2022, FMT for CPE and VRE decolonization in the gut was conducted at Hallym University Chuncheon Sacred Heart Hospital. Frozen or capsulized stool (MicroBiotix FMT Delivery Microbiota Preparation) from unrelated pre-screened healthy donor was used for each FMT. The rates of and the time to successful decolonization, defined as 3 consecutive negative results from rectal swab culture repeated with 3-day intervals after the initial FMT, were investigated in CPE and VRE rectal colonizers, respectively. Results FMT was performed in 60 CPE rectal carriers (KPC=55, KPC &amp; NDM=2, KPC &amp; IMP=1, NDM=1, NDM &amp; OXA=1) and in 15 VRE rectal carriers (E. faecium=14, E. faecalis=1). Among patients with follow-up data after initial FMT, decolonization success rates for CPE and VRE rectal carriers were 44.8% (26/58) and 66.7% (10/15) at 1 month, 77.1% (37/48) and 92.9% (13/14) at 3 months, 95.5% (42/44) and 100% (14/14) at 6 months, respectively. Median and mean times to decolonization after initial FMT were 30 and 43 days in CPE rectal colonizers and 14 and 29 days in VRE rectal colonizers, respectively. FMT results for decolonization of MDROs in the gut of Chuncheon Sacred Heart Hospital (ClinicalTrials.gov number, NCT04583098) Conclusion FMT as a microbiome restoration therapy is an effective method to control CPE and VRE colonization (ClinicalTrials.gov number, NCT04583098). Disclosures All Authors: No reported disclosures

Association of patient clinical and gut microbiota features with vancomycin-resistant enterococci environmental contamination in nursing homes: a retrospective observational study

Preventing transmission is crucial for reducing infections with multidrug-resistant organisms (MDROs) in nursing homes. To identify resident characteristics associated with MDRO spread, we investigated associations between patient characteristics and contamination of their proximate room surfaces with vancomycin-resistant enterococci (VRE). In this retrospective observational study, we used demographic and clinical data (including data on comorbidities, physical independence, catheter use within the past 30 days, and antibiotic exposure within the past 30 days) and surveillance cultures of patient body sites and room surfaces at enrolment and during weekly follow-up visits within the first month, and monthly thereafter (up to 6 months), in six US nursing homes collected in a previous clinical trial (September, 2016, to August, 2018). We did 16S rRNA gene sequencing on perirectal surveillance swabs to investigate the association between the gut microbiota and the culture status of participants and their rooms. We included 245 participants (mean age 72·5 years [SD 13·6]; 111 [45%] were men, 134 [55%] were women, 132 [54%] were non-Hispanic white, and 112 [46%] were African American). We collected 2802 participant samples and 5592 environmental samples. At baseline, VRE colonisation was present in 49 (20%) participants, with environmental surfaces being contaminated in 36 (73%) of these patients. Hand contamination among VRE-colonised participants was more common in those with environmental contamination compared with those without (50 [51%] of 99 vs seven [13%] of 55; p<0·0001). We found a correlation between hand contamination and both groin and perirectal colonisation and contamination of various high-touch room surfaces (Cohen's κ 0·43). We found participant microbiota composition to be associated with antibiotic receipt within the past 30 days (high-risk antibiotics p=0·011 and low-risk antibiotics p=0·0004) and participant VRE colonisation status, but not environmental contamination among VRE-colonised participants (participant only vs uncolonised p=0·071, both participant and environment vs uncolonised p=0·025, and participant only vs participant and environment p=0·29). Multivariable analysis to identify independent factors associated with VRE-colonised participants contaminating their environment identified antibiotic exposure (adjusted odds ratio 2·75 [95% CI 1·22-6·16]) and male sex (2·75 [1·24-6·08]) as being associated with increased risk of environmental contamination, and physical dependence as being associated with a reduced risk of environmental contamination (0·91 [0·83-0·99]). Our data support antibiotic use and interaction with proximal surfaces by physically independent nursing home residents as under-appreciated drivers of environmental contamination among VRE-colonised residents. Integrating resident hand-hygiene education and antimicrobial stewardship will strengthen efforts to reduce MDROs in nursing homes. US Centers for Disease Control and Prevention, National Institute of Health, Canadian Institutes of Health Research, and University of Michigan.

Perioperative daptomycin for prophylaxis of vancomycin-resistant Enterococcus infection in colonized liver transplant recipients.

Infection with vancomycin-resistant Enterococcus (VRE) in liver transplant recipients (LTR) has been associated with extended hospital stays, increased readmission rates, graft failure, and death. A tailored perioperative surgical prophylaxis regimen targeting VRE may reduce postoperative infections in VRE-colonized patients. This study investigated the outcomes of perioperative daptomycin in this patient population. This retrospective, single-center cohort study included LTR ≥ 18 years old who were VRE-colonized from June 2018 to November 2022. VRE colonization was identified by a VRE rectal swab screen or a positive VRE culture prior to transplant. Two groups were analyzed: daptomycin versus no daptomycin. All LTR received perioperative piperacillin-tazobactam for 24 h. If VRE-colonized, one dose of daptomycin (6mg/kg) was given pre- and postoperatively. Demographics, clinical characteristics, risk factors for VRE infection, and daptomycin dose were collected. The primary outcome was VRE infection at 14 days and 90 days post-transplant. There were 36 VRE-colonized LTR; 19 received daptomycin and 17 did not. Baseline characteristics and risk factors for VRE infection were similar between groups. More VRE infections occurred in the no daptomycin group within 14 days post-transplant (24%vs. 0%, p = .04), but at 90 days posttransplant there was no significant difference (29%vs. 16%, p = .43). The average daptomycin dose was 7.1mg/kg. Perioperative daptomycin reduced the rate of VRE infections in VRE-colonized LTR within 14 days posttransplant but not at 90 days. Future studies should evaluate if higher doses and/or longer duration of perioperative daptomycin can reduce VRE infections beyond 14 days post-transplant.

Diversity and persistence of MRSA and VRE in skilled nursing facilities: environmental screening, whole-genome sequencing and development of a dispersion index

Environmental contamination with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) in skilled nursing facilities (SNFs) may contribute to patient acquisition. We assessed diversity and association of MRSA and VRE isolates in a SNF wing and developed a mathematical index to define each strain's tendency to persist in rooms and spread horizontally. Longitudinal study of MRSA and VRE colonization and contamination among successive patient occupancies in a cluster of nine SNF private rooms during eight months characterized by microbiological testing and whole genome isolate typing. 'Dispersion index" of a strain is defined as the number of rooms it was found in (including the patient), divided by the average of times it was found consecutively in the same room. MRSA (ten strain types) and VRE (seven types) were recovered from room or patient in 16.4% and 35.6% of the occupancies, respectively. MRSA showed moderate horizontal spread and several episodes of same-room persistence (three distinct strain types) (overall dispersion index: 1.08). VRE showed high tendency towards horizontal spread /new introductions (overall dispersion index: 3.25), and only one confirmed persistence episode. The emerging picture of high diversity among contaminating strains and high likelihood of room persistence despite terminal cleaning (MRSA) and horizontal spread between rooms (VRE) in this setting calls for improved cleaning practices, heightened contact precautions, and most of all to establish individually tailored facility screening programs to enable informed choices based on local, measurable and actionable epidemiologic parameters. University of Michigan OAIC REC Scholarship to M.C. National Institutes of Health K24 AG050685 to L.M.

The Evaluation of Risk Factors for Vancomycin-Resistant Enterococcus Colonization and Infection Among Mixed Adult Intensive Care Unit Patients.

Background and objective Despite the adherence to strict infection control measures, vancomycin-resistant enterococcus (VRE) colonization and VRE infections are still important problems nowadays. However, there are only a limited number of studies examining the factors causing the transformation of VRE colonization to VRE infection in the intensive care unit (ICU). The aim of this study is to delineate the prevalence of VRE colonization and its transformation into infection and the risk factors leading to infection. Methods Patients admitted to the third-level mixed-type ICU from 2012 to 2015 for at least 24 hoursand acquired VRE colonization and VRE infection, both during and after their admission, were included in the study, and their medical records were examined retrospectively. VRE rectal swabs were taken weekly from each patient on admission and discharge from the ICU. If the VRE-positive patient was detected negative for VRE on the rectal swap taken three times in total as a surveillance culture successively, this patient was accepted as VRE negative. Demographic data, Acute Physiology and Chronic Health Evaluation II (APACHE-II) scores, invasive procedures, treatments (corticosteroid, antibiotic, etc.), nutrition types, laboratory results, and ICU results were recorded. Results Among 1730 patients admitted to ICU, 101 (5.8%) were found to carry VRE colonization. Twelve (11.8%) out of 101 patients colonized with VRE developed VRE infection. About 56.4% had urinary tract infections, 68.3% had pneumonia, 15.8% had surgical site infections, and 24.8% had catheter-associated infections among these infected patients. The most prevalent factor was Enterococcus faecium in patients with VRE colonization (64.3%) and infection (91%). VRE turned negative in 67% of patients with VRE colonization during their stay in ICU. Renal replacement therapy was statistically significant (p < 0.05) in the group with VRE infection (66.7%) compared to the VRE-colonized group (26.1%). Infection development risk among carriers of VRE for more than one week was again found statistically significant (p = 0.025). Demographic data, APACHE-II scores, treatments, nutrition type, previous antibiotic usage and types, invasive procedures, laboratory results, and ICU results were similar among the patients with VRE colonization and infection. Conclusion A longer duration of ICU stay in patients with colonization and previous renal replacement therapy increases the transformation of VRE colonization to VRE infection. Strategies towarddecreasing VRE-colonized patients' period of stay in ICU is the main objective to control the rate of VRE infection.

2111. Impact of Colonization by Multi Drug Resistant Bacteria on Graft Survival, Risk of Infection, and Mortality in Recipients of Solid Organ Transplant: Systematic Review and Meta-analysis

Abstract Background Colonization with multi-drug resistant bacteria (MDR) in solid organ transplant (SOT) recipients increases the risk of post-transplant bacterial infection. MDR colonization impact on graft survival and mortality is not well established. Methods A search was executed by an expert librarian on PROSPERO, OVID Medline, Ovid EMBASE, Wiley Cochrane Library, ProQuest dissertations and Theses Global and SCOPUS, from inception until October 26, 2021. Adult SOT colonized with Methicillin resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococci (VRE), Extended-spectrum beta-lactamase (ESBL) or AmpC producing bacteria, carbapenem resistant Enterobacteriaceae (CRE), or MDR Pseudomonas were included and compared to non-colonized SOT. Pairs of reviewers screened abstracts and full studies for inclusion, and extracted data independently. We used RevMan to conduct a meta-analysis using random effects models to calculate the pooled risk ratio (RR) with 95% confidence interval (CI) for the incidence of infection, mortality, and graft failure. Statistical heterogeneity was determined using the I2 statistic. Figure-1 PRISMA chart, systemic review and metanalysis on Impact Of Colonization By Multi Drug Resistant Bacteria on Graft Survival, Risk of Infection, and Mortality in Recipients of Solid Organ Transplant. Results 59 articles spanning from 1989 to 2021 were included (Figure-1). Liver transplant (43 studies) and VRE colonization (17 studies) were the most common organ and MDR pathogen. MDR surveillance was performed by culture (71%) and PCR (6.7%). In liver transplant recipients, VRE and MRSA colonization were associated with increased infection risk, but not mortality (VRE infection: RR= 2.40 (95%CI 1.54-3.73; p&amp;lt; 0.001), I2= 66%; VRE mortality: RR= 1.64 (95%CI 0.88-3.05; p=0.12), I2= 44%; MRSA infection: RR= 4.07 (95%CI 2.66-6.24; p&amp;lt; 0.001), I2= 59%; MRSA mortality RR=1.47 (95%CI 0.79-2.76; p=0.23), I2= 35%). ESBL and CRE colonization were associated with increased risk of infection (ESBL: RR=9.87 (6.12-15.93); p&amp;lt; 0.001), I2=13%; CRE: RR= 13.64 (95%CI 5.73-32.47); p&amp;lt; 0.001), I2= 66%). CRE colonization was associated with increased mortality, RR=5.79 (95% CI 1.80-18.63; p=0.003), I2=0%. Conclusion While colonization with MRSA and VRE in liver transplant was not associated with increase mortality, CRE colonization was associated with almost 6-fold increased risk of death. These data should be taken into account when stratifying the risk of transplant. Disclosures Carlos Cervera, Associate Professor, Astra-Zeneca: Advisor/Consultant|AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|Lilly: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Merck: Honoraria|Sunovion: Advisor/Consultant|Takeda: Advisor/Consultant|Takeda: Honoraria|VerityPharma: Advisor/Consultant Dima Kabbani, MD, MSc, AVIR Pharma: Grant/Research Support|AVIR Pharma: Honoraria|GSK: Honoraria|Merck: Grant/Research Support.

Microbiome-mediated fructose depletion restricts murine gut colonization by vancomycin-resistant Enterococcus

Multidrug-resistant organisms (MDRO) are a major threat to public health. MDRO infections, including those caused by vancomycin-resistant Enterococcus (VRE), frequently begin by colonization of the intestinal tract, a crucial step that is impaired by the intestinal microbiota. However, the specific members of the microbiota that suppress MDRO colonization and the mechanisms of such protection are largely unknown. Here, using metagenomics and mouse models that mimic the patients’ exposure to antibiotics, we identified commensal bacteria associated with protection against VRE colonization. We further found a consortium of five strains that was sufficient to restrict VRE gut colonization in antibiotic treated mice. Transcriptomics in combination with targeted metabolomics and in vivo assays indicated that the bacterial consortium inhibits VRE growth through nutrient depletion, specifically by reducing the levels of fructose, a carbohydrate that boosts VRE growth in vivo. Finally, in vivo RNA-seq analysis of each strain of the consortium in combination with ex vivo and in vivo assays demonstrated that a single bacterium (Olsenella sp.) could recapitulate the effect of the consortium. Our results indicate that nutrient depletion by specific commensals can reduce VRE intestinal colonization, which represents a novel non-antibiotic based strategy to prevent infections caused by this multidrug-resistant organism.

Impact of a change in universal gloving protocol on rates of central line-related bloodstream infection, Clostridioides difficile, and vancomycin-resistant Enterococcus

In this retrospective cohort of adult hematology-oncology and transplant patients, discontinuation of universal gloving did not result in significant changes in rates of central line-associated bloodstream infection, Clostridioides difficile infection, or vancomycin-resistant Enterococcus colonization. Active surveillance and subsequent isolation may be a viable alternative strategy to universal precautions.

Extending outbreak investigation with machine learning and graph theory: Benefits of new tools with application to a nosocomial outbreak of a multidrug-resistant organism.

From January 1, 2018, until July 31, 2020, our hospital network experienced an outbreak of vancomycin-resistant enterococci (VRE). The goal of our study was to improve existing processes by applying machine-learning and graph-theoretical methods to a nosocomial outbreak investigation. We assembled medical records generated during the first 2 years of the outbreak period (January 2018 through December 2019). We identified risk factors for VRE colonization using standard statistical methods, and we extended these with a decision-tree machine-learning approach. We then elicited possible transmission pathways by detecting commonalities between VRE cases using a graph theoretical network analysis approach. We compared 560 VRE patients to 86,684 controls. Logistic models revealed predictors of VRE colonization as age (aOR, 1.4 (per 10 years), with 95% confidence interval [CI], 1.3-1.5; P < .001), ICU admission during stay (aOR, 1.5; 95% CI, 1.2-1.9; P < .001), Charlson comorbidity score (aOR, 1.1; 95% CI, 1.1-1.2; P < .001), the number of different prescribed antibiotics (aOR, 1.6; 95% CI, 1.5-1.7; P < .001), and the number of rooms the patient stayed in during their hospitalization(s) (aOR, 1.1; 95% CI, 1.1-1.2; P < .001). The decision-tree machine-learning method confirmed these findings. Graph network analysis established 3 main pathways by which the VRE cases were connected: healthcare personnel, medical devices, and patient rooms. We identified risk factors for being a VRE carrier, along with 3 important links with VRE (healthcare personnel, medical devices, patient rooms). Data science is likely to provide a better understanding of outbreaks, but interpretations require data maturity, and potential confounding factors must be considered.

Neutropenic enterocolitis and multidrug-resistant bacteria colonization in lymphoma patients undergoing autologous stem cell transplantation

Introduction: There is little iterature data regarding neutropenic enterocolitis (NE) development after autologous hematopoietic cell transplantation (auto-HCT) in non-Hodgkin lymphoma (NHL) patients. The aim of this study was to determine the incidence, risk factors, and clinical outcome of NE after auto-HCT in NHL patients with respect to the impact of multidrug-resistant Gram-negative bacteria (MDRG) and vancomycin-resistant enterococci colonization on the early outcome after auto-HCT. Material and methods: This retrospective single-center analysis included a total of 65 NHL patients who underwent auto-HCT after BEAM (BCNU, etoposide, cytosine arabinoside, melphalan) conditioning (BEAM-auto-HCT). Results: NE was diagnosed in nine (13.8%) patients, a median four days after auto-HCT. In 6/9 (66%) patients, septic shock following NE was diagnosed. In univariate analysis, MDRG colonization before BEAM-auto-HCT was the only factor significant for NE development [odds ratio (OR) 2.4 (1.14–5.0), p = 0.027], although this was not confirmed in multivariate analysis. Additionally, NE [OR 5.2 (1.9–13.9), p = 0.001] and MDRG colonization prior to transplant [OR 2.7 (1.0–7.0), p = 0.041] were independent factors for septic shock development. Conclusions: Our findings suggest that NHL patients presenting with MDRG colonization before transplant should be kept under careful surveillance because of the high risk of the development of early severe infectious complications, including abdominal ones.

The Clinical Importance of Preoperative Rectal Swabs in Patients after Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

Background: Surgical site infections are among the most common healthcare-associated infections, especially in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The aim of this retrospective study was to examine postoperative infectious complications according to preoperative screening findings of nasal and rectal swabs. Methods: Two hundred four consecutive patients received nasal and rectal swab examination for multidrug-resistant (MDR) bacteria within 30 days before the operation in patients where CRS and HIPEC were planned. Inclusion criteria were as follows: confirmed peritoneal metastases (histologically and/or cytologically); age under 85 years; adequate renal, liver, and bone marrow function; no sign of infection preoperatively; resectable disease; and CRS and HIPEC procedure. If surgical site infection occurred, the microbial spectrum of the site was assessed. One hundred twenty-one patients (63 female [52.1%] and 58 male [47.9%]) met the criteria and were further analyzed retrospectively. Statistical correlations between postoperative complications and risk factors were investigated by univariate and multivariate analysis. Results: Postoperative complications in total were observed in 57 patients (47.1%) with major complications (Clavien-Dindo grades 3–4) in 15 patients (12.4%) and infectious complications in 37 (30.6%) patients. The overall prevalence of nasal MRSA carriage was 3.28%, and the overall prevalence of rectal MDR bacteria carriage was 10.7%. In propensity score analysis, colonized patients compared to noncolonized patients showed increased total complications (CD1–5, p = 0.025), infectious complications (p = 0.028), surgical site infections (p = 0.022) as well as pneumonia (p = 0.016). Multivariate analysis showed that in addition to preoperative rectal colonization, American Society of Anesthesiologists score was a risk factor for postoperative complications. Conclusions: Preoperative 3-MRGN and vancomycin-resistant enterococcus colonization were associated with increased complications and surgical site infections. Special antimicrobial treatment pathways are necessary for these patients to reduce postoperative complications due to colonization.

Prevalence, risk factors, and molecular analysis of vancomycin-resistant Enterococci colonization in a referral neonatal intensive care unit: a prospective study in northern Iran

Vancomycin-resistant enterococcus (VRE) is an emerging drug-resistant organism responsible for increasing nosocomial infections. Few data are available on the epidemiology of VRE colonization or infection in neonates, and is of recent interest. This study analyzes the prevalence of neonatal VRE colonization in a neonatal intensive care unit (NICU), and describes risk factors and molecular phenotypes associated with VRE colonization. We performed a prospective epidemiological study on neonates admitted to an NICU. We compared neonates with VRE isolates detected in rectal swab cultures to those without. Association of VRE colonization with risk factors was tested by using univariate and multivariate methods. During a period of 18 months, amongst 180 neonates enrolled in the study, 76 (42.2%) were colonized by VRE. VRE isolates were resistant to amikacin in 68%, gentamicin in 26%, and ampicillin in 17.1% of cases. Molecular analysis showed the vanA gene in all isolates. Two VRE-positive patients developed infection during the observation time. No deaths occurred during this period. Prematurity (P=0.023), low birth weight (P=0.019), history of admission in other hospitals (P=0.00), and antibiotic therapy for more than seven days (P=0.01) were identified as risk factors for VRE colonization. Newborn susceptibility to early colonization with VRE in NICUs is increased in preterm and low birth weight newborns. All VRE colonization in the NICU was related to the acquisition of the vanA gene. Adherence to infection control policies and antimicrobial stewardship strategies are of the highest importance.