Multidrug-resistant Organisms Colonization Research Articles

Risk of invasive MDRO infection in MDRO-colonized patients.

In this study, we aim to estimate the risk of developing clinical multidrug-resistant organism (MDRO) infection with carbapenem-resistant Enterobacterales (CRE), methicillin-resistant Staphylococcus aureus (MRSA), or vancomycin-resistant enterococci (VRE) in colonized patients compared with non-colonized admitted to high-risk areas with a main focus on CRE colonization/infection. Retrospective cohort study conducted at a tertiary care facility. This study included patients enrolled in active surveillance testing (AST) for CRE, MRSA, or VRE during the year 2021. Development of relevant invasive infection within 365 days of the AST result was collected as the primary outcome. The association between MDRO colonization and infection was calculated using the risk ratio. The prevalence of CRE organisms and carbapenemase genes is presented. A total of 19,134 ASTs were included in the analysis (4,919 CRE AST, 8,303 MRSA AST, and 5,912 VRE AST). Patient demographics were similar between colonized and non-colonized groups. Colonization was associated with an increased risk of infection in the 3 cohorts (CRE, MRSA, and VRE), with risk ratios reported as 4.6, 8.2, and 22, respectively. Most patients (88%) develop CRE infection with the same colonizing carbapenemase gene. Oxa-48/NDM Klebsiella pneumoniae was the most common organism detected in CRE infection. The study demonstrated that colonization with CRE, MRSA, or VRE is a risk factor for developing infections caused by the respective bacteria. The high percentage of match between carbapenemase genes detected in colonization and infection indicates that screening results might be used to inform infection management and treatment.

Males are at higher risk of colonization and infection with multi-drug-resistant organisms than females

Global rise of multidrug-resistant organisms (MDRO) is alarming and antimicrobial resistance (AMR) poses a significant public health threat globally. Although certain risk factors are known including recent antimicrobial therapy, inappropriate use and hospitalization, the focus on gender-specific aspects in MDRO is scarce. Our aim was to show gender-specific differences in colonization and infections of multiple MDRO and their detection sites. For this multicentre, retrospective cohort study surveillance data between 2015 and 2020 was collected in 86 hospitals of the Helios group, Germany. The following multidrug-resistant bacteria were analysed according to sample site: MRSA, Enterococcus spp., Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Acinetobacter baumannii. Out of the 7,081,708 cases in the database, 187,656 patients were found to be colonized with MDRO (2.65%). A documented infection with MDRO was identified in 33,023 patients (0.466%), with the origin of infection known in 24,231 cases. Male gender was a risk factor for both infection and colonization of any MDRO (p< .001). Males exhibited a higher likelihood of MDRO detection in superficial skin/soft tissue, blood cultures (p < .001), and respiratory samples (p = .002). Additionally, gender-specific differences in MDRO detection site and pathogens were found with slightly higher proportion of MRSA infection in deep skin/soft tissue and respiratory samples for females. Our study reinforces the existing hypothesis that male gender is a risk factor for MDRO, supported by our large dataset. It highlights the need to acknowledge gender-specific MDRO susceptibility in clinical practice.

Optimizing the implementation of Enhanced Barrier Precautions in community-based nursing homes

BackgroundEnhanced Barrier Precautions (EBP) recommends using gowns and gloves for certain nursing home residents during specific high-contact care activities associated with multidrug-resistant organism (MDRO) transmission. Though EBP is included in CDC guidance as an MDRO control strategy, optimal implementation approaches remain unclear. MethodsWe implemented a quality improvement initiative using the 4E process model (Engagement, Education, Execution, and Evaluation) to optimize EBP implementation in four Maryland nursing homes. Semi-structured interviews with healthcare personnel (HCP) occurred to understand EBP acceptability. ResultsGlove use during high-contact care increased from 85% in the baseline to 97% during the intervention (p<0.01). Gown use increased from 27% to 78% (p<0.01). Accuracy of identifying residents eligible for EBP improved from 63% to 99% (p<0.01). Of 780 residents observed, one-third met EBP indications - MDRO colonization (21%), indwelling medical device (14%), and/or chronic wound (10%). The most noted facilitator to EBP implementation included HCP perception that EBP reduces MDRO transmission to other residents and staff. The most noted barrier was uncomfortable gowns. ConclusionsImplementation was complex and required comprehensive assessments of barriers and facilitators within each facility. HCP interviews identified common barriers and facilitators of EBP that can inform future EBP implementation projects.

Efficacy of Empiric Contact Precautions for Patients from High Risk Facilities

Background: Infection prevention surveillance revealed that patients admitted from two specific long term care facilities comprised the majority of multi-drug resistant organisms (MDRO) and scabies cases at our institution. Current practices include performing active surveillance for Candida auris and methicillin-resistant Staphylococcus aureus (MRSA) for specific high-risk patients, as surveillance for all MDROs and scabies is impractical. We therefore sought to create an admission screening process to efficiently identify patients from high-risk facilities (HRFs) and place them in pre-emptive contact precautions upon admission. Methods: Patients admitted from HRFs were identified on admission as part of the initial nursing assessment. For any positive responses, nursing received a Best Practice Advisory to place the patient in contact precautions and patient placement received an alert that the patient would require a private room. Infection Preventionists reviewed a report of all patients who screened positive and added a “High Risk Facility” banner to the chart. This banner remained for the duration of hospitalization and for every subsequent readmission and outpatient visit. We reviewed the electronic medical records of all patients with a HRF banner placed from March 8, 2023 to September 15, 2023 and abstracted data regarding the presence of scabies or any of the following MDROs before and after placement of the banner: C. auris, carbapenem-resistant enterobacterales (CRE), MRSA, vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Acinetobacter, and MDR Pseudomonas. Results: Of the 93 patients who had a HRF banner added during the study period, 31 (33.33%) were already known to have MDRO colonization at the time of admission to our facility. Thirty-three of the remaining 62 patients (53.22%) without known MDRO colonization were subsequently found to have MDRO colonization/infection or scabies infestation that may have required contact precautions during their index admission or a subsequent admission. This included 14 patients with C. auris, 2 with CRE, 3 with MDR Pseudomonas, 12 with MRSA, 12 with carbapenem-resistant Acinetobacter, and 2 with VRE. Patients were admitted for a median of 9 days before their diagnosis, and 36 of the 93 patients (38.71%) were re-admitted to our hospital during the study period. Conclusion: We found that empiric contact precautions based solely on exposure to specific HRFs facilitated earlier isolation by a median of 9 days. This approach should be considered in acute care hospitals with a high proportion of admissions from HRFs, especially when active and passive surveillance for MDROs is limited.

MDRO Colonization Among Nursing Homes Patients: A Risk Classification Tool for Early Identification

Background: Nursing homes (NHs) have high prevalence of multi-drug resistant organisms (MDROs) with rates exceeding those in hospitals. This study proposes quantifying patients’ risk of MDRO colonization and creating a risk profile for the NH patient populations to assist in reducing MDRO burden in health care facilities. Methods: We assessed a risk classification model using data from a prospective cohort study (2018 Pathways study). Patient sample included 783 newly admitted patients followed for up to 180 days and 9,587 samples collected from patients during 2,089 visits. Individual risk factors of MDRO colonization were assessed using unadjusted logistic regression, and patients were risk classified based on number of risk factors. Multivariate regression was performed to obtain odds of MDRO colonization for patient risk groups adjusting for patient age, sex, race, and length of NH stay (LOS). The risk classification tool developed using Pathways data was also tested among a sample of NH residents from Veterans Administration (N=190). Results: The patient sample (Pathways data) was 43.2% male, 37.2% Black with a mean age 74 years. 69.3% were colonized with a MDRO during the study. In unadjusted regression, recent antibiotic use (p&lt;.001), open wounds (p&lt;.05), use of urinary catheter or feeding tube (p&lt;.001), functional disability (p&lt;.001), diabetes (p&lt;.01), and preadmission hospital stay over 14 days (p&lt;.001) were associated with colonization, while Charlson comorbidity score, age, sex, and race were not. In adjusted analysis (c-statistic=0.75), a patient’s colonization risk increased with the number of risk factors (Figure 1), with 47.2% expected colonization among patients with none of the risk factors and 86.7% expected colonization among patients with four or more risk factors. The risk classification model had similar performance among male and female patients, and among Black and White patients (Figure 2). Secondary analysis using data obtained from separate, Veterans Administration facilities provided preliminary validation of the risk scoring tool. The model had acceptable fit (c-statistic=0.71). Veterans with four or more risk factors had 87.8% expected probability of MDRO colonization compared with 39.6% colonization among those without any risk factors. Veterans with less than four risk factors also had higher colonization, but these differences were not statistically significant. Conclusions. Despite system-wide efforts to reduce MDRO burden, prevalence of MDRO colonization remains high in NHs. The risk classification tool can assist in early identification of most vulnerable NH patients to direct targeted interventions such as education, enhanced environmental cleaning, and active surveillance.Disclosure: Lona Mody: NIH, VA, CDC, Kahn Foundation; Honoraria: UpToDate; Contracted Research: Nano-Vibronix

Gut colonization with multidrug resistant organisms in the intensive care unit: a systematic review and meta-analysis

BackgroundGut colonization with multidrug-resistant organisms (MDRO) frequently precedes infection among patients in the intensive care unit (ICU), although the dynamics of colonization are not completely understood. We performed a systematic review and meta-analysis of ICU studies which described the cumulative incidence and rates of MDRO gut acquisition.MethodsWe systematically searched PubMed, Embase, and Web of Science for studies published from 2010 to 2023 reporting on gut acquisition of MDRO in the ICU. MDRO were defined as multidrug resistant non-Pseudomonas Gram-negative bacteria (NP-GN), Pseudomonas spp., and vancomycin-resistant Enterococcus (VRE). We included observational studies which obtained perianal or rectal swabs at ICU admission (within 48 h) and at one or more subsequent timepoints. Our primary outcome was the incidence rate of gut acquisition of MDRO, defined as any MDRO newly detected after ICU admission (i.e., not present at baseline) for all patient-time at risk. The study was registered with PROSPERO, CRD42023481569.ResultsOf 482 studies initially identified, 14 studies with 37,305 patients met criteria for inclusion. The pooled incidence of gut acquisition of MDRO during ICU hospitalization was 5% (range: 1–43%) with a pooled incidence rate of 12.2 (95% CI 8.1–18.6) per 1000 patient-days. Median time to acquisition ranged from 4 to 26 days after ICU admission. Results were similar for NP-GN and Pseudomonas spp., with insufficient data to assess VRE. Among six studies which provided sufficient data to perform curve fitting, there was a quasi-linear increase in gut MDRO colonization of 1.41% per day which was stable through 30 days of ICU hospitalization (R2 = 0.50, p < 0.01).ConclusionsAcquisition of gut MDRO was common in the ICU and increases with days spent in ICU through 30 days of follow-up. These data may guide future interventions seeking to prevent gut acquisition of MDRO in the ICU.

Results of an Italian multi-Long-Term Care Facilities survey on diagnostic, therapeutic, and infection control topics: state of the art and future perspective

Background and Aims: current trends in the world’s demographic structure indicate increasing requirements for chronic and Long-Term Care Facilities (LTCFs). As the above settings may act as reservoirs for Multidrug-Resistant Organisms (MDROs), it is essential to acquire information about diagnostic, therapeutic, and infection control practices, aiming to optimize strategies for the near future. Materials and Methods: the annual survey form for assessment of the MDRO management in LTCFs and Residential Homes (RHs) for non-self-sufficient elderly people, promoted by the Centers for Disease Control (CDC), and adapted by the version of the American National Healthcare Safety Network, was sent to LTCFs healthcare operators by the AMCLI GLISTer Working Group. Topics considered were interactions with clinical microbiology laboratories, infection prevention/control and antibiotic stewardship practices, and electronic medical records data availability. Results and Conclusions: sixteen structures, mostly from 120 to 280 beds, took part in the survey. We registered that i) MDRO colonization screening is usually not adopted in Italian LTCFs for new admissions (14; 87,5%) at present, and ii) microbiological results are usually provided by an external laboratory service. Furthermore, infection control interventions are regularly adopted, and antibiotic prescriptions are registered only in 62,5% and 75% of structures, respectively. About 70% of facilities do not have a strategy for antibiotic use optimization. Planning of 1st/2nd/3rd level MDRO surveillance programs, enhanced training activities, and improved antibiotic consumption control, whether for prophylaxis, empirical, and targeted therapy, appears of paramount importance in the complex reality of LTCFs.

Comparison of Daily Versus Admission and Discharge Surveillance Cultures for Multidrug-Resistant Organism Detection in an Intensive Care Unit.

Admission and discharge screening of patients for asymptomatic gut colonization with multidrug-resistant organisms (MDROs) is a common approach to active surveillance, but its sensitivity for detecting colonization is uncertain. Daily rectal or fecal swab samples and associated clinical data were collected over 12 months from patients in one 25-bed medical intensive care unit (ICU) in Chicago, IL and tested for the following MDROs: vancomycin-resistant enterococci; third-generation cephalosporin-resistant Enterobacterales, including extended-spectrum β-lactamase-producing Enterobacterales; and carbapenem-resistant Enterobacterales. MDRO detection by (1) admission and discharge surveillance cultures or (2) clinical cultures were compared to daily surveillance cultures. Samples underwent 16S rRNA gene sequencing to measure the relative abundance of operational taxonomic units (OTUs) corresponding to each MDRO. Compared with daily surveillance cultures, admission/discharge cultures detected 91% of prevalent MDRO colonization and 63% of MDRO acquisitions among medical ICU patients. Few (7%) MDRO carriers were identified by clinical cultures alone. Higher relative abundance of MDRO-associated OTUs and specific antibiotic exposures were independently associated with higher probability of MDRO detection by culture. Admission and discharge surveillance cultures underestimated MDRO acquisitions in an ICU. These limitations should be considered when designing sampling strategies for epidemiologic studies that use culture-based surveillance.

Impact of a multidisciplinary management team on clinical outcome in ICU patients affected by Gram-negative bloodstream infections: a pre-post quasi-experimental study

BackgroundBloodstream infections (BSIs) by Gram-negative pathogens play a major role in intensive care patients, both in terms of prevalence and severity, especially if multi-drug resistant pathogens are involved. Early appropriate antibiotic therapy is therefore a cornerstone in the management of these patients, and growing evidence shows that implementation of a multidisciplinary team may improve patients’ outcomes. Our aim was to evaluate the clinical and microbiological impact of the application of a multidisciplinary team on critically ill patients.MethodsPre-post study enrolling critically ill patients with Gram negative bloodstream infection in intensive care unit. In the pre-intervention phase (from January until December 2018) patients were managed with infectious disease consultation on demand, in the post-intervention phase (from January until December 2022) patients were managed with a daily evaluation by a multidisciplinary team composed of intensivist, infectious disease physician, clinical pharmacologist and microbiologist.ResultsOverall, 135 patients were enrolled during the study period, of them 67 (49.6%) in the pre-intervention phase and 68 (50.4%) in the post-intervention phase. Median age was 67 (58–75) years, sex male was 31.9%. Septic shock, the need for continuous renal replacement therapy and mechanical ventilation at BSI onset were similar in both groups, no difference of multidrug-resistant organisms (MDRO) prevalence was observed. In the post-phase, empirical administration of carbapenems decreased significantly (40.3% vs. 62.7%, p = 0.02) with an increase of appropriate empirical therapy (86.9% vs. 55.2%, p < 0.001) and a decrease of overall antibiotic treatment (12 vs. 16 days, p < 0.001). Despite no differences in delta SOFA and all-cause 30-day mortality, a significant decrease in microbiological failure (10.3% vs. 29.9%, p = 0.005) and a new-onset 30-day MDRO colonization (8.3% vs. 36.6%, p < 0.001) in the post-phase was reported. At multivariable analysis adjusted for main covariates, the institution of a multidisciplinary management team (MMT) was found to be protective both for new MDRO colonization [OR 0.17, 95%CI(0.05–0.67)] and microbiological failure [OR 0.37, 95%CI (0.14–0.98)].ConclusionsThe institution of a MMT allowed for an optimization of antimicrobial treatments, reflecting to a significant decrease in new MDRO colonization and microbiological failure among critically ill patients.

The Burden and Impact of Early Post-transplant Multidrug-Resistant Organism Detection Among Renal Transplant Recipients, 2005-2021.

Reducing the burden of multidrug-resistant organism (MDRO) colonization and infection among renal transplant recipients (RTRs) may improve patient outcomes. We aimed to assess whether the detection of an MDRO or a comparable antibiotic-susceptible organism (CSO) during the early post-transplant (EPT) period was associated with graft loss and mortality among RTRs. We conducted a retrospective cohort study of RTRs transplanted between 2005 and 2021. EPT positivity was defined as a positive bacterial culture within 30 days of transplant. The incidence and prevalence of EPT MDRO detection were calculated. The primary outcome was a composite of 1-year allograft loss or mortality following transplant. Multivariable Cox hazard regression, competing risk, propensity score-weighted sensitivity, and subgroup analyses were performed. Among 3507 RTRs, the prevalence of EPT MDRO detection was 1.3% (95% CI, 0.91%-1.69%) with an incidence rate per 1000 EPT-days at risk of 0.42 (95% CI, 0.31-0.57). Among RTRs who met survival analysis inclusion criteria (n = 3432), 91% (3138/3432) had no positive EPT cultures and were designated as negative controls, 8% (263/3432) had a CSO detected, and 1% (31/3432) had an MDRO detected in the EPT period. EPT MDRO detection was associated with the composite outcome (adjusted hazard ratio [aHR], 3.29; 95% CI, 1.21-8.92) and death-censored allograft loss (cause-specific aHR, 7.15; 95% CI, 0.92-55.5; subdistribution aHR, 7.15; 95% CI, 0.95-53.7). A similar trend was seen in the subgroup and sensitivity analyses. MDRO detection during the EPT period was associated with allograft loss, suggesting the need for increased strategies to optimize prevention of MDRO colonization and infection.

Predictors for multidrug-resistant organisms (MDROs) carriage in haemodialysis patients.

Infections in haemodialysis (HD) patients are an important cause of morbidity, hospitalization, and mortality. Patients undergoing HD are more prone to develop bacterial infections by multidrug-resistant organisms (MDROs). This study is aimed to detect MDROs colonization in HD patients and its associated risk factors and outcome. A total of 62 nasal swabs and 124 rectal swabs were collected from 62 patients coming to the haemodialysis unit from of March to May 2021 and were further screened for MRSA, VRE and CRE. Out of 62 patients, 22.59% showed the presence of methicillin-resistant staphylococcus aureus (MRSA) while VRE was present in four patients (4/62). CRE was found as 24.2% (15/62). Duration of dialysis was found as a significant risk factor-associated MRSA carriage, Whereas Charlson index and drug and medication were found as significant risk factor for VRE carriage. HD patients are particularly vulnerable to life threatening infections. Therefore, continuous epidemiological surveillance for these MDROs, including genotypic analysis and implementation of adequate decolonization strategies, is crucial and will reduce the possibility of autoinfection as well as disrupt transmission of multi-resistant isolates to others.

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.

Bring it on again: antimicrobial stewardship in transplant infectious diseases: updates and new challenges.

Advancement in solid organ transplantation and hematopoietic stem cell transplant continues to improve the health outcomes of patients and widens the number of eligible patients who can benefit from the medical progress. Preserving the effectiveness of antimicrobials remains crucial, as otherwise transplant surgeries would be unsafe due to surgical site infections, and the risk of sepsis with neutropenia would preclude stem cell transplant. In this review, we provide updates on three previously discussed stewardship challenges: febrile neutropenia, Clostridioides difficile infection, and asymptomatic bacteriuria. We also offer insight into four new stewardship challenges: the applicability of the "shorter is better" paradigm shift to antimicrobial duration; antibiotic allergy delabeling and desensitization; colonization with multidrug-resistant gram-negative organisms; and management of cytomegalovirus infections. Specifically, data are accumulating for "shorter is better" and antibiotic allergy delabeling in transplant patients, following successes in the general population. Unique to transplant patients are the impact of multidrug-resistant organism colonization on clinical decision-making of antibiotic prophylaxis in transplant procedure and the need for antiviral stewardship in cytomegalovirus. We highlighted the expansion of antimicrobial stewardship interventions as potential solutions for these challenges, as well as gaps in knowledge and opportunities for further research.

Risk factors for surgical site infection following cardiac surgery in a region endemic for multidrug resistant organisms

ObjectivesTo identify risk factors for surgical site infections following cardiosurgery in an area endemic for multidrug resistant organisms. DesignSingle-center, historical cohort study including patients who underwent cardiosurgery during a 6-year period (2014–2020). SettingJoint Commission International accredited, multiorgan transplant center in Palermo, Italy. Main outcome measuresSurgical site infection was the main outcome. ResultsOn a total of 3609 cardiosurgery patients, 184 developed surgical site infection (5.1 %). Intestinal colonization with multidrug resistant organisms was more frequent in patients with surgical site infections (69.6 % vs. 33.3 %; p < 0.001). About half of surgical site infections were caused by Gram-negative bacteria (n = 97; 52.7 %). Fifty surgical site infections were caused by multidrug resistant organisms (27.1 %), with extended-spectrum Beta-lactamase-producing Enterobacterales (n = 16; 8.7 %) and carbapenem-resistant Enterobacterales (n = 26; 14.1 %) being the predominant resistance problem. However, in only 24 of surgical site infections caused by multidrug resistant organisms (48 %), mostly carbapenem-resistant Enterobacterales (n = 22), a pathogen match between the rectal surveillance culture and surgical site infections clinical culture was demonstrated. Nevertheless, multivariate logistic regression analysis identified a rectal swab culture positive for multidrug resistant organisms as an independent risk factor for SSI (odds ratio 3.95, 95 % confidence interval 2.79–5.60). Other independent risk factors were female sex, chronic dialysis, diabetes mellitus, previous cardiosurgery, previous myocardial infarction, being overweight/obese, and longer intubation time. ConclusionIn an area endemic for carbapenem-resistant Enterobacterales, intestinal colonization with multidrug resistant organisms was recognized as independent risk factor for surgical site infections. Implications for clinical practiceNo causal relationship between colonization with resistant pathogens and subsequent infection could be demonstrated. However, from a broader epidemiological perspective, having a positive multidrug resistant organisms colonization status appeared a risk factor for surgical site infections. Therefore, strict infection control measures to prevent cross-transmission remain pivotal (e.g., nasal decolonization, hand hygiene, and skin antisepsis).

Screening for multidrug-resistant organisms in high-risk hospitalized patients with hematologic diseases.

Patients treated for hematologic malignancies are at higher risk for blood stream infections (BSI) and multidrug-resistant organisms (MDRO) are increasingly involved. Studies showed a significant association between rectal colonization status and a higher risk of subsequent MDRO BSI. The objective of our study was to probe the practice of surveillance cultures in Belgian hematology centers. A questionnaire was sent to the 13 hematology centers participating in the acute leukemia board of the Belgian Hematology Society. 21 questions probed for the method of surveillance cultures, MDRO screened, antimicrobial prophylaxis, and empirical therapy and their relationship with colonization status. All centers completed the questionnaire in full. Routine gastrointestinal surveillance cultures in hematologic patients are taken in 10 hospitals. Organisms tested for included mostly ESBL (n = 9) and carbapenem-resistant (n = 8) Enterobacterales. All centers with a screening strategy adapt empiric antibiotic therapy based on MDRO colonization. Prophylaxis strategies are variable, only two centers adapt prophylaxis upon documentation of fluoroquinolone resistance. The majority of the Belgian centers perform routine surveillance cultures and adapt empiric therapy for neutropenic fever accordingly. Other reasons for testing include to gain insight into local epidemiology and to prevent in-hospital transmission. In general, there was significant variability in surveillance dimensions.

300. Disturbance of Gut Microbial Diversity in ICU Patients from Colombia is Driven by Multi-Drug Resistant Organisms (MDRO) Colonization

Abstract Background Gut microbiota plays a critical role in health, with essential functions in physiology, metabolism, immunity, regulation, and protection against pathogens. Critically-ill patients admitted on the ICU experience perturbation in the microbiota, with reduction in the phylogenetic diversity and composition. Here, we aimed to investigate the rectal microbiota in patients admitted on the ICU from Colombia, focused on MDRO colonization. Methods Microbiome analysis and microbiological screening for MDRO and WGS were performed in rectal swabs taken on admission day from 180 patients from 5 ICUs. Microbiome analysis was determined by 16S rRNA sequencing using Illumina Miseq platform. alpha-diversity metrics were calculated by Richness, Simpson, and Shannon indexes, and beta-diversity was determined using Similarity Percentages (SIMPER) analysis. Patients were grouped into 2 cohorts: MDRO-colonized and non-colonized. Clinical data was collected using REDCap. Results MDRO colonization was detected in 13 patients (7%), and Enterobacter cloacae complex was the most prevalent microorganism (38%), followed by K. pneumoniae (23%), and P. aeruginosa (15%). Of these MDRO, 23% and 15% harbored KPC-2 and KPC-3/OXA-9 combination, respectively. Prevotella and Bacteroides were the most abundant genus in the microbiota of all patients. Interestingly, microbiota of MDRO-colonized patients showed lower diversity (Shannon p:0.0025, Simpson p: 0.0031 and richness 0.012) and had less bacterial taxa than the observed in the non-colonized group (n=167), in which Bacteroides, Porphyromonas, Campylobacter, and Oscillospiraceae genus were exclusively detected. Moreover, Parabacteroides was a genus exclusively identified in the MDRO colonized group. Further, 14 genus including Oscillospiraceae, Lactobacillus, and Faecalibacterium related to beneficial functions were lower in abundance from MDRO-colonized patients, whereas some pathobionts were present in high abundance in this group. Most of patients were men (58%); median age was 59 y/o. Charlson comorbidity index 4 (IQR=1-6). Conclusion Loss in microbial diversity, with low abundance of beneficial microorganisms were associated with MDRO gut colonization in ICU patients from Colombia. Disclosures Karen Melissa Ordoñez, n/a, Pfizer: Advisor/Consultant|Pfizer: Honoraria

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

Comparison of Risk Stratification Approaches to Identify Patients with Clostridioides difficile Infection at Risk for Multidrug-Resistant Organism Gut Microbiota Colonization.

Multidrug-resistant organisms (MDRO) commonly colonize the gut microbiota of patients with Clostridioides difficile infection (CDI). This increases the likelihood of systemic infections with these MDROs. To help guide MDRO screening and/or empiric antibiotic therapy, we derived and compared predictive indices for MDRO gut colonization in patients with CDI. This was a multicenter, retrospective cohort study of adult patients with CDI from July 2017 to April 2018. Stool samples were screened for MDRO via growth and speciation on selective antibiotic media and confirmed using resistance gene polymerase chain reaction. Aregression-based risk score for MDRO colonization was constructed. Predictive performance via area under the receiver operating characteristic curve (aROC) of this index was compared with two other simplified risk stratification approaches: (1) prior healthcare exposure and/or high-CDI risk antibiotics; (2) number of prior high-CDI risk antibiotics. 50 (20.8%) of 240 included patients had MDRO colonization; 35 (14.6%) VRE, 18 (7.5%) MRSA, 2 (0.8%) CRE. Prior fluoroquinolone (aOR 2.404, 95%CI 1.095-5.279) and prior vancomycin (1.996, 95%CI 1.014-3.932) were independently associated with MDRO colonization while prior clindamycin (aOR 3.257, 95%CI 0.842-12.597) and healthcare exposure (aOR 2.138, 95%CI 0.964-4.740) were retained as explanatory variables. The regression-based risk score significantly predicted MDRO colonization (aROC 0.679, 95%CI 0.595-0.763), but was not significantly more predictive than prior healthcare exposure + prior antibiotics (aROC 0.646, 95%CI 0.565-0.727) or number of prior antibiotic exposures (aROC 0.642, 95%CI 0.554-0.730); P > 0.05 for both comparisons. A simplified approach using prior healthcare exposure and receipt of prior antibiotics known to increase CDI risk identified patients at risk for MDRO gut microbiome colonization as effectively as individual patient/antibiotic risk modeling.

Construction and validation of a predictive risk model for nosocomial infections with MDRO in NICUs: a multicenter observational study.

This study aimed to construct and validate a predictive risk model (PRM) for nosocomial infections with multi-drug resistant organism (MDRO) in neonatal intensive care units (NICUs), in order to provide a scientific and reliable prediction tool, and to provide reference for clinical prevention and control of MDRO infections in NICUs. This multicenter observational study was conducted at NICUs of two tertiary children's hospitals in Hangzhou, Zhejiang Province. Using cluster sampling, eligible neonates admitted to NICUs of research hospitals from January 2018 to December 2020 (modeling group) or from July 2021 to June 2022 (validation group) were included in this study. Univariate analysis and binary logistic regression analysis were used to construct the PRM. H-L tests, calibration curves, ROC curves and decision curve analysis were used to validate the PRM. Four hundred and thirty-five and one hundred fourteen neonates were enrolled in the modeling group and validation group, including 89 and 17 neonates infected with MDRO, respectively. Four independent risk factors were obtained and the PRM was constructed, namely: P = 1/ (1+ ), X = -4.126 + 1.089× (low birth weight) +1.435× (maternal age ≥ 35 years) +1.498× (use of antibiotics >7 days) + 0.790× (MDRO colonization). A nomogram was drawn to visualize the PRM. Through internal and external validation, the PRM had good fitting degree, calibration, discrimination and certain clinical validity. The prediction accuracy of the PRM was 77.19%. Prevention and control strategies for each independent risk factor can be developed in NICUs. Moreover, clinical staff can use the PRM to early identification of neonates at high risk, and do targeted prevention to reduce MDRO infections in NICUs.

Epidemiology and Prevention of Early Infections by Multi-Drug-Resistant Organisms in Adults Undergoing Liver Transplant: A Narrative Review.

Invasive bacterial infections are a leading cause of morbidity and mortality after liver transplant (LT), especially during the first months after LT, and infections due to multi-drug-resistant organisms (MDRO) are increasing in this setting. Most of the infections in patients in intensive care unit arise from the endogenous microflora and, for this reason, pre-LT MDRO rectal colonization is a risk factor for developing MDRO infections in the post-LT. Moreover, the transplanted liver may carry an increased risk of MDRO infections due to organ transportation and preservation, to donor intensive care unit stay and previous antibiotic exposure. To date, little evidence is available about how MDRO pre-LT colonization in donors and recipients should address LT preventive and antibiotic prophylactic strategies, in order to reduce MDRO infections in the post-LT period. The present review provided an extensive overview of the recent literature on these topics, with the aim to offer a comprehensive insight about the epidemiology of MDRO colonization and infections in adult LT recipients, donor-derived MDRO infections, possible surveillance, and prophylactic strategies to reduce post-LT MDRO infections.