Multidrug-resistant Organisms Colonization Research Articles

Predicting Vancomycin-Resistant Enterococci (VRE) and Carbapenem-Resistant Organism (CRO) Colonization in the Intensive Care Unit

Background: Rapidly identifying patients colonized with multidrug-resistant organisms (MDROs) upon ICU admission is critical to control and prevent the spread of these pathogens in healthcare facilities. Electronic health records (EHR) provide a rich source of data to predict the likelihood of MDRO colonization at admission, whereas surveillance methods are resource intensive and results are not immediately available. Our objectives were (1) to predict VRE and CRO colonization at ICU admission and (2) to identify patient subpopulations at higher risk for colonization with these MDROs. Methods: We conducted a retrospective analysis of patients aged ≥16 years admitted to any of 6 medical or surgical intensive care units (ICU) in the Johns Hopkins Hospital from July 1, 2016, through June 30, 2018. Perirectal swabs were collected at ICU unit admission and were tested for VRE and CRO. Patient demographic data, prior hospitalizations, and preadmission clinical data, including prior medication administration, prior diagnoses, and prior procedures, were extracted to develop prediction models. We employed the machine-learning algorithms logistic regression (LR), random forest (RF), and XGBoost (XG). The sum of sensitivity and specificity (ie, Youden’s index) was selected as the performance metric. Results: In total, 5,033 separate ICU visits from 3,385 patients were included, where 555 (11%) and 373 (7%) admissions tested positive for VRE and CRO, respectively. The sensitivity and specificity of our models for VRE were 78% and 80% with LR, 80% and 82% with RF, and 77% and 87% with XG. Predictions for CRO were not as precise, with LR at 73% and 53%, RF at 81% and 48%, and XG at 69% and 61%. The XG algorithm was the best-performing algorithm for both VRE and CRO. Prior VRE colonization, recent (<180 days) long-term care facility stay, and prior hospitalization >60 days were the key predictors for VRE, whereas the primary predictor for CRO colonization was prior carbapenem use. Conclusions: We demonstrated that EHR data can be used to predict >75% of VRE positive cases with a <15% false-positive rate and ~70% of CRO cases with a <40% false-positive rate. Future studies using larger sample sizes may improve the prediction accuracy and inform model generalizability across sites and thus reduce the risk of transmission of MDROs by rapidly identifying MDRO-colonized patients.Funding: This work was funded by the Centers for Disease Control and Prevention (CDC) Epicenters Program (Grant Number 1U54CK000447) and the CDC MInD-Healthcare Program (Grant Number 1U01CK000536).Disclosures: Aaron Milstone, BD (consulting)

Epidemiology of NDM-Producing Enterobacteriaceae in Michigan

Background: Carbapenem-resistant Enterobacteriaceae (CRE) are classified as an urgent antibiotic-resistant threat by the CDC, and they are listed on the critical priority list by the World Health Organization due to the lack of antibiotic treatment options. New-Delhi metallo-β-lactamase (NDM) is an emerging mechanism of carbapenem resistance in the United States. We sought to understand the risk factors and clinical characteristics of patients with NDM CRE in Michigan to improve surveillance. Methods:A retrospective descriptive study was conducted in collaboration with the Michigan Department of Health and Human Services (MDHHS). CRE isolates submitted to MDHHS between April 2014 and July 2019 were tested for the presence of NDM using CDC PCR protocols. Additional information on case demographics, laboratory results, healthcare and antibiotic exposure history, and travel history were collected. Results: In total, 30 NDM cases were identified in Michigan during the study period. Of these 30 cases, 15 (50%) were men, and the median age was 73.5 years (range, 20–88 20). Also, 2 of these patients (6.6%) were immunocompromised; 2 patients (6.6%) had had extensive abdominal surgery, and 2 patients (6.6%) had recurrent hospitalization. Furthermore, 12 case isolates (40%) were collected in outpatient settings, whereas 16 (53%) were collected from inpatient settings. In addition, 13 (43%) patients were admitted from home and 4 (13%) presented from an extended-care facility. Urine was the most common site of isolation in 19 of 30 (63%) cases, followed by blood and tissue culture in 4 of 30 (13%) each. Escherichia coli was the most common organism (17 of 30, 57%), followed by Klebsiella pneumoniae (9 of 30, 30%). Also, 15 of 30 cases (50%) had a recent history of international travel, and of these, 9 of 15 (60%) reported travel to India. Among these 15 cases, 12 (80%) sought medical care in the countries they visited. Two cases (6.6%) had a documented history of multidrug-resistant organism colonization or infection. The mortality rate was 6.6% (2 of 30). The mean time from admission to implementation of contact precautions was 7.3 days (range, 0–20). Conclusions: Suspicion of NDM CRE strains should remain high in patients with a travel history from areas known as major reservoirs of NDM. Delay in implementing contact precautions, as noted in the present study, can lead to a greater risk of transmission. Early detection and subsequent isolation of NDM patients are essential strategies for preventing transmission within healthcare facilities. Future efforts include performing whole-genome sequencing of these isolates to assist in identifying potential epidemiological links among the affected patients.Funding: NoneDisclosures: None

The use of fecal microbiota transplantation in the treatment of intestinal diseases

Introduction and purpose Fecal microbiota transplantation (FMT) is a process of transferring gut microflora from a healthy donor to a recipient. It is indicated that the human distal gastrointestinal tract consists of more than 1000 species of bacteria, which have an impact on local and systemic processes related to immunity, nutrition and the gut-brain axis. The growth of new bacterial species, reduction of microbial variety or big changes in the ratio between them can lead to a dysbiosis. The relationship between intestinal microbiota and some systemic diseases is seen.The study aimed to present the state of knowledge on FMT in the treatment of intestinal diseases. Publications from the last 5 years from the Pubmed database were included.A brief description of the state of knowledgeIntestinal diseases constitute the main group of indications for FMT. FMT can be delivered via upper or lower gastrointestinal routes. The review presents different studies concerning the usage of FMT. Among them, recurrent Clostridium difficile infection, colitis ulcerosa, Crohn’s disease and irritable bowel syndrome are mainly indicated in the literature. FMT might find its application also in a treatment of multidrug-resistant organisms colonization, antibiotic-associated diarrhea, gut acute graft-versus-host disease and radiation enteritis. There is a possibility of the occurrence of adverse events from the digestive tract after FMT. However, the studies evaluate them as mostly mild and transient. In some cases it was necessary to repeat FMT to achieve a satisfactory final result.ConclusionsFecal microbiota transplantation gives hope for a safe and effective method of treatment of certain intestinal diseases. There is a need for conducting further analysis of the method.

Comparison of the novel Uroquattro HB&L™ system and classical phenotypic method for rapid screening of multidrug-resistant organism colonization at the University Hospital Centre Split, Croatia

Background. Infections caused by multidrug-resistant organisms (MDRO) are difficult to treat and associated with poor outcomes for patients. Therefore, early identification and management of colonization are essential as first steps in infection prevention. Culture-based methods have been widely used for MDRO screening. The turnaround time (TAT) for the identification of carriers varies between 48-72 h with this method. The aim of our study was to compare the performance of the new rapid semiautomatic method for detection of MDRO (HB&L Uroquattro, Alifax) with standard cultivation on selective media. Methods. Twenty-one axillary, 20 nose and 19 rectal swabs were taken in duplicate on two selected days at the University Hospital Centre Split, Croatia. Swabs were cultivated and MDRO isolates were identified on selective media (Chromagar MRSA and Chromagar ESBL) according to the standard operating procedure. Novel Alifax method was performed according to manufacturer’s instructions. Results. TAT for the new method was significantly lower (6.5 h) in comparison to the classical method. With classical method, 10 extended spectrum ß-lactamases (ESBL) producing strains from 10 different rectal specimens were isolated on Chromagar ESBL media. Exactly the same specimens were positive for the presence of ESBL-producing bacteria by rapid Alifax method. On selective Chromagar MRSA media, 11 MDRO were isolated, while rapid method detected 11 MDRO from the same specimens. Conclusions. High concordance of positive and negative results obtained with classical and rapid method is encouraging. However, our study was performed on a small sample size and further research with larger sample size is needed.

Metagenomic next-generation sequencing of rectal swabs for the surveillance of antimicrobial-resistant organisms on the Illumina Miseq and Oxford MinION platforms.

Antimicrobial resistance (AMR) is a public health threat where efficient surveillance is needed to prevent outbreaks. Existing methods for detection of gastrointestinal colonization of multidrug-resistant organisms (MDRO) are limited to specific organisms or resistance mechanisms. Metagenomic next-generation sequencing (mNGS) is a more rapid and agnostic diagnostic approach for microbiome and resistome investigations. We determined if mNGS can detect MDRO from rectal swabs in concordance with standard microbiology results. We performed and compared mNGS performance on short-read Illumina MiSeq (N = 10) and long-read Nanopore MinION (N = 5) platforms directly from rectal swabs to detect vancomycin-resistant enterococci (VRE) and carbapenem-resistant Gram-negative organisms (CRO). We detected Enterococcus faecium (N = 8) and Enterococcus faecalis (N = 2) with associated van genes (9/10) in concordance with VRE culture-based results. We studied the microbiome and identified CRO, Pseudomonas aeruginosa (N = 1), Enterobacter cloacae (N = 1), and KPC-producing Klebsiella pneumoniae (N = 1). Nanopore real-time analysis detected the blaKPC gene in 2.3min and provided genetic context (blaKPC harbored on pKPC_Kp46 IncF plasmid). Illumina sequencing provided accurate allelic variant determination (i.e., blaKPC-2) and strain typing of the K. pneumoniae (ST-15). We demonstrated an agnostic approach for surveillance of MDRO, examining advantages of both short- and long-read mNGS methods for AMR detection.

Impact of multicenter unified enhanced environmental cleaning and disinfection measures on nosocomial infections among patients in intensive care units.

ObjectivesMost Chinese hospitals have customized environmental cleaning policies and systems, with limited data availability based on evidence-based medicine. This study investigated the relationship between multidrug-resistant organism (MDRO) colonization in intensive care unit (ICU) patients and ICU surface bacterial contamination status.MethodsThis cross-sectional study comprised MDRO screening in ICU patients using bacterial cultivation by chromogenic medium; samples were collected before (control group) and after implementation of enhanced cleaning (cleaning group). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to identify and analyze microorganisms; the relationships of MDRO colonization with infection and environmental bacteria were analyzed.ResultsIn total, 196 patients were enrolled in the study (104 and 92 in control and cleaning groups, respectively); 1042 MDROs were subjected to screening before and after cleaning. After cleaning, the rate of MDRO detection on surfaces of frequently touched objects in ICUs decreased from 31.77% to 13.32%. There were fewer MDRO homologues in the cleaning group than in the control group. Moreover, the cleaning group had a shorter ICU stay and significantly lower mortality rate.ConclusionsEnhanced environmental cleaning and disinfection could reduce environmental MDRO accumulation and suppress MDRO colonization in ICUs, thereby reducing nosocomial infections and improving adverse patient outcomes.

Multidrug Resistant Organism Burden in Critically-Ill Burn Patients

<h3>Background</h3> The National Burn Repository 2019 reports burn-related data from July 2017- June 2018 of 1,101 hospitals and 221,519 patients. Large total body surface area (TBSA) burns and inhalational lung injury (ILI) are major risks for a complicated course requiring critical care support and infections are the most serious and most common complications of burns. The aim of this study is to evaluate the burden of multidrug resistant organisms (MDRO) in critically-ill burn patients. <h3>Methods</h3> Our burn center receives 3,000 visits and provides treatment for around 1300 patients annually. In 2018, 225 patients were admitted to the hospital's 9-bed critical-care burn unit. Patients who had burns more than 10% TBSA and/or ILI were included in the study if they survived more than 48 hours. The records were reviewed for length of stay (LOS), mortality, as well as MDRO clinical as well surveillance cultures. <h3>Results</h3> 55 patients were included in the study with 39 (71%) male and with an average LOS of 11 days. Inhalational lung injury was found to be present in 58% of patients. 8 patients died who had an average TBSA burn of 60%. While patients who were discharged alive had average TBSA burns of 29% and average LOS of 26 days. 22% of discharged patients were found to have MDRO acquisition detected by clinical cultures and 14% of patients had MRSA detected by follow-up nasal screening. <h3>Conclusions</h3> MDRO colonization is common in severely-ill burn patients. This highlights the importance of more aggressive MDRO surveillance in this population for early detection and prevention of hospital-associated infections and outbreaks.

Prevalence of Multi-Resistant Microorganisms and Antibiotic Stewardship among Hospitalized Patients Living in Residential Care Homes in Spain: A Cross-Sectional Study.

Antimicrobial resistance is a growing global health problem. Patients living in care homes are a vulnerable high-risk population colonized by multidrug-resistant organisms (MDRO). We identified a case series of 116 residents of care homes from a cohort of 540 consecutive patients admitted to the internal medicine service of our hospital. We performed early diagnostic tests of MDRO through anal exudates in our sample. The prevalence of MDRO colonization was 34.5% of residents and 70% of them had not been previously identified in the clinical records. Previous hospitalizations and in-hospital antibiotic administration were significantly associated with the presence of MDRO. Our results emphasize the need to consider care homes in the planning of regional and national infection control measures and for implementing surveillance systems that monitor the spread of antimicrobial resistance in Spain. Systematic early testing upon admission to hospital services with a high prevalence of patients with MDRO colonization (e.g., internal medicine) could contribute to the adoption of adequate prevention measures. Specific educational programs for care home staff should also be implemented to address this increasing problem.

Targeted Multidrug Resistant Organism Antimicrobial Prophylaxis and Postoperative Infections in Pediatric Cardiothoracic Surgical Patients.

To determine if receiving targeted antimicrobial (AM) prophylaxis has an effect on the rate of postoperative infections in patient's colonized with a multidrug resistant organism (MDRO) undergoing cardiothoracic surgery (CTS). Single-center, retrospective medical record review of pediatric patients from birth to 18 years of age undergoing CTS from January 2013 to September 2018. Demographic data collected included age, specific MDRO, site of MDRO colonization, type of surgery, perioperative AM agent and type of infection. Patients were stratified into 2 groups, MDRO+ and MDRO-. Demographic and clinical characteristics were compared between groups with a Student's t test for continuous variables and a χ2, Fisher exact test or Mann-Whitney U test for noncontinuous variables. A 2-sided significance level of α = 0.05 was used to determine statistical significance. All analyses were performed using IBM SPSS Version 24 (SPSS Inc., Chicago, IL). Fifty patients (26 males/24 females) were included in the MDRO (+) group and 295 patients (168 males/127 females) in the MDRO (-) group. The median age was 0.48 years (interquartile range 0.24-1 year) and 0.9 years (interquartile range 0.19-8 years) in the MDRO (+) and MDRO (-) groups, P = 0.003. 2 of 50 (4%) MDRO (+) patients and 15 of 295 (5.1 %) MDRO (-) patients developed an infection, P = 1. 10 of 50 (20%) MDRO (+) patients received targeted AM toward the MDRO and none developed an infection. Of the 2 MDRO (+) patients with infection, 1 was infected with the MDRO. For MDRO (+) patients, there was no difference in the rate of infection whether targeted AM therapy was received, P = 1. There was no difference in the rate of postoperative infection between MDRO (+) and MDRO (-) patients. Additionally, these preliminary pediatric data suggest targeting AM agents to a specific MDRO does not impact the rate of postoperative infection in children undergoing CTS. Larger studies are warranted to confirm these findings.

Predicting the occurrence of multidrug-resistant organism colonization or infection in ICU patients: development and validation of a novel multivariate prediction model

BackgroundMultidrug-resistant organisms (MDROs) have emerged as an important cause of poor prognoses of patients in the intensive care unit (ICU). This study aimed to establish an easy-to-use nomogram for predicting the occurrence of MDRO colonization or infection in ICU patients.MethodsIn this study, we developed a nomogram based on predictors in patients admitted to the ICU in the First Affiliated Hospital of Xiamen University from 2016 to 2018 using univariate and multivariate logistic regression analysis. We externally validated this nomogram in patients from another hospital over a similar period, and assessed its performance by calculating the area under the receiver operating characteristic (ROC) curve (AUC) and performing a decision curve analysis.Results331 patients in the primary cohort and 181 patients in the validation cohort were included in the statistical analysis. Independent factors derived from the primary cohort to predict MDRO colonization or infection were male sex, higher C-reactive protein (CRP) levels and higher Pitt bacteremia scores (Pitt scores), which were all assembled in the nomogram. The nomogram yielded good discrimination with an AUC of 0.77 (95% CI 0.70–0.84), and the range of threshold probabilities of decision curves was approximately 30–95%.ConclusionThis easy-to-use nomogram is potentially useful for predicting the occurrence of MDRO colonization or infection in ICU patients.

Impact of Geographical Variations on the Prevalence of Multidrug-Resistant Organisms in Japan.

Emergence and spread of multidrug-resistant organisms (MDRO) is an urgent social and public health problem. Here, we carried out an epidemiological survey to clarify the geographical characteristics and factors influencing the prevalence of MDRO. Data on the prevalence of MDRO in 47 prefectures in Japan were extracted from the Japanese Nosocomial Infection Surveillance, a nationwide database for infection control. Potential factors for MDRO were analyzed using data selected from the pharmacological, medical service, infection control, environmental, social, and food-related categories, based on the characteristics of each organism and the correlations between them and MDRO prevalence. Statistical data for potential factors were obtained from public domains. The use of antibiotics was found to be correlated with the prevalence of penicillin-resistant Streptococcus pneumoniae, 3rd-generation cephalosporin- and fluoroquinolone-resistant Escherichia coli, and methicillin-resistant Staphylococcus aureus. Negative correlation between the consumption of food such as kelp and fermented soybeans that facilitate the growth of lactic acid bacteria and the prevalence of 3rd-generation cephalosporin- and fluoroquinolone-resistant E. coli suggested an association between the intestinal microflora and MDRO colonization. In addition to the use of antibiotics, lifestyle, food culture, and social factors such as tobacco smoking, average atmospheric temperature, prevalence of three-generation households, ratio of elderly population, average duration of tourist stay, chicken and fermented soybean consumption, and the competency of healthcare services may also affect MDRO prevalence.

High prevalence of MDR gram-negative bacteria in feces of healthy blood donors in Mexico.

During the initial stage of a study to recruit universal intestinal microbiota donors in Mexico City, we found multiple "healthy" subjects that colonized with MDRO (Multidrug-resistant organisms). We aimed to describe clinical and demographic characteristics of these individuals. This was a prospective observational study. Participants were consecutively recruited among blood donors. A fecal sample was collected from each subject and analyzed at the same day in search of MDRO through chromographic culture media and, if growth observed, later confirmed by MALDI-TOF and susceptibility testing in Vitek 2 system. From July 2018 to March 2019, 85 individuals were screened for fecal colonization. Median age was 35years (IQR 27-46years), and 48/85 (56.4%) were males. Seventy-two (84.7%) subjects harbored at least one MDRO. ESBL-producing microorganisms were found in 72/85 (84.3%) subjects, and E. coli was the most frequent (63/85, 74.1%). Four samples (2 E. coli, 2 P. aeruginosa, 2.4% each) harbored carbapenem-resistant Enterobacteriaceae (CRE), together with an ESBL-producing microorganism. Antibiotic use (p = 0.06) and PPIs or H2-blockers intake (p = 0.03) were more common in the colonized subjects during the previous 6-month period. We report a high incidence of enteric colonization of healthy subjects with MDRO, a condition that may be related to antibiotics or PPIs/H2-blockers consumption. This surprisingly high MDRO colonization rate in potential FMT donors emphasizes the need for careful screening of donors to avoid possible transmission to FMT recipients.

Association between Clostridioides difficile infection and multidrug-resistant organism colonization or infection among hospitalized adults: A case-control study

Using an ambidirectional case-control study, we found that the odds of Clostridioides difficile infection (CDI) were 3.38 (P = .01) times higher for patients with multidrug-resistant organism (MDRO) colonization compared to those without. MDRO colonization or infection 1-12 months before CDI testing significantly increased risk of positive CDI diagnosis (odds ratio 4.71, P = .02 and odds ratio = 5.03, P = .05, respectively) independent of antibiotic use, age, and comorbidity status. MDRO colonization and infection are associated with CDI, most significantly if they precede CDI.

Depression and anxiety in hospitalized patients on contact precautions for multidrug-resistant microorganisms.

Contact precautions for patients with multidrug-resistant organisms (MDROs) have been associated with adverse effects. The aim of this study was, therefore, to evaluate the level of anxiety and depression through different standardized scales in patients isolated by MDROs. This is a case-control study with hospitalized patients on contact precautions for MDROs. A questionnaire survey was conducted to analyse the presence and level of depression and anxiety. A multivariable analysis was performed to define independent questions for anxiety/depression scores to create a short questionnaire facilitating a practical approach to the care of hospitalized patients with MDROs. A receiver operating characteristic (ROC) curve was plotted to determine the diagnostic ability of the simplified score. A total of 141 patients were included in the study, among whom 68 were isolated because of MDRO colonization while 73 were not isolated (control-group). Forty-five (31.9%) patients had some degree of anxiety. Patients in MDRO contact isolation had a higher level of anxiety than those who were not isolated (55.9% vs. 9.6%, p<0.001). The equation obtained by multivariated analysis allowed for the construction of a score with ROC area of 0.949 and a sensitivity of 91.1%. Contact isolation for MDROs is associated with increased depression and anxiety. A simple anxiety score was developed and should be validated for screening.

Bacterial, Gut Microbiome-Modifying Therapies to Defend against Multidrug Resistant Organisms.

Antibiotics have revolutionized human and animal healthcare, but their utility is reduced as bacteria evolve resistance mechanisms over time. Thankfully, there are novel antibiotics in the pipeline to overcome resistance, which are mentioned elsewhere in this special issue, but eventually bacteria are expected to evolve resistance to most new compounds as well. Multidrug resistant organisms (MDROs) that cause infections increase morbidity, mortality, and readmissions as compared with susceptible organisms. Consequently, many research and development pipelines are focused on non-antibiotic strategies, including fecal microbiota transplantation (FMT), probiotics and prebiotics, and a range of therapies in between. Studies reviewed here focus on efforts to directly treat or prevent MDRO infections or colonization. The studies were collected through clinicaltrials.gov, PubMed, and the International Conference on the Harmonisation Good Clinical Practice website (ichgcp.net). While the gold standard of clinical research is randomized controlled trials (RCTs), several pilot studies are included because the field is so young. Although a vast preclinical body of research has led to studies in humans, animal and in vitro studies are not within the scope of this review. This narrative review discusses microbiome-modifying therapies targeting MDROs in the gut and includes current results, ongoing clinical trials, companies with therapies in the pipeline specifically for MDROs, and commentary on clinical implementation and challenges.

Prevalence of Multidrug-Resistant Organisms and Risk Factors for Carriage among Patients Transferred from Long-Term Care Facilities.

BackgroundPatient transport between acute care hospitals and long-term care facilities (LTCFs) plays a significant role in microbial migration. The study aimed to estimate the prevalence and risk factors associated with the colonization of multidrug-resistant organisms (MDROs) among patients transferred from LTCFs.Materials and MethodsWe retrospectively reviewed medical records to examine the colonization of MDROs. All patients who were transferred from LTCFs and admitted to an acute care hospital with 800 beds in Daejeon between March 2018 and February 2019 were included in the study. We surveyed rectal cultures and nasal swabs obtained for screening vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Enterobacteriaceae (CRE), and methicillin-resistant Staphylococcus aureus (MRSA) at the time of hospitalization. We conducted a multivariable logistic regression to assess the association between clinical variables and the carriage of MDROs.ResultsFour hundred and fifteen patients from 86 LTCFs were enrolled. A total of 31.1% (130/415) of participants carried MDROs; VRE colonization was detected in 17.1% (71/415) of participants, and MRSA colonization was shown in 19.5% (81/415) of participants. No CRE was isolated. Previous use of antibiotics within three months [odds ratio (OR) 2.28; (95% confidence interval (CI) 1.30 - 4.00), P = 0.004], use of antibiotics for longer than two weeks [OR 2.16; (95% CI 1.03 - 4.53), P = 0.040], and previous colonization of MDROs within one year [OR 2.01; (95% CI 1.15 - 3.54), P = 0.015] were independently associated with increased risk for carriage of MDROs.ConclusionOur study showed that a third of patients transferred from LTCFs carried VRE or MRSA, and prior antibiotic therapy was highly associated with the carriage of MDROs, which suggested more efficient management approaches for high-risk patients.

1180. Colonization with Multidrug-Resistant Organisms Is Associated with Subsequent Infection in the Ventricular Assist Device Population

BackgroundInfection is a leading cause of morbidity and mortality in the ventricular assist device (VAD) population. We performed a retrospective cohort study outlining the epidemiology of multidrug-resistant organism (MDRO) colonization and infection rates in this population.MethodsWe performed a longitudinal retrospective cohort of all patients receiving continuous-flow (axial and centrifugal) ventricular assist devices from July 2008 to September 2018 at Northwestern Memorial Hospital. Peri-operative prophylaxis from July 2008 to June 2013 was vancomycin, rifampin, ciprofloxacin, and fluconazole, and vancomycin plus cefuroxime from June 2013 to September 2018. VAD-specific and VAD-related Infections were classified according to ISHLT 2013 definitions. Patients were screened for methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis or Enterococcus faecium, or extended-spectrum β-lactamase producing Gram-negative rods. Statistics were performed using IBM® SPSS Statistics version 25.0. Comparative statistics were performed using two-sided Fisher’s exact test with a P-value of <0.05 deemed significant.ResultsA total of 89 patients with ventricular assist devices developed either VAD-specific or VAD-related infections and were included in the analysis. 77% of patients (n = 66) were colonized with an MDRO; 29% (n = 25) with MRSA, 73% (n = 63) with VRE, and 24% (n = 21) with an ESBL organism. 17.9% (n = 16) of patients who went on to develop infection was secondary to MDROs. Colonization with an MDRO was associated with subsequent infection secondary to these organisms (P = 0.018).ConclusionColonization rates of multidrug-resistant organisms in the VAD population are high. VRE rates were significantly higher than MRSA or ESBL, possible as a result of peri-implantation utilization of vancomycin as surgical site prophylaxis. MDRO colonization was associated with progression to VAD-specific or VAD-related Infection.Disclosures All authors: No reported disclosures.

2391. Increased Risk of Systemic Infections with Multidrug-Resistant Organisms in Patients with Severe Clostridioides difficile Infection

BackgroundThe gut microbiota is a defense mechanism against colonization of multidrug-resistant organisms (MDROs), including carbapenem-resistant Enterobacteriacae (CRE). Gut dysbiosis caused by broad-spectrum antibiotics favors MDRO colonization and increased susceptibility of intestinal infections, including C. difficile infection (CDI). Increased CDI severity may increase the risk of bacterial translocation due to damage to colonic epithelial layer. The aim of this study was to assess CDI disease severity and subsequent risk for MDRO systemic infection.MethodsThis was a prospective, observational study of adult hospitalized patients tested for CDI at a large, university-affiliated tertiary care hospital. Patients with a history of systemic MDRO infection in the past 90-days of stool testing were excluded. Patients were stratified by test positivity (CDI vs. antibiotic-associated diarrhea (AAD)), as well as, CDI disease severity and followed for 30-days for subsequent MDRO infections defined as presence of MDRO cultures from systemic, normally sterile sites (blood, urine, cerebrospinal fluid). Stool samples were collected and grown for MDRO colonization.ResultsA total of 335 CDI-positive and 135 antibiotic-associated diarrhea (AAD) hospitalized patients were included. No differences were found in rates of MDRO colonization by test positivity or disease severity (overall 68% VRE, 53% Candida spp., 30.4% MRSA, and 1.8% CRE). Significantly more patients with severe CDI had higher rates of developing systemic MDROs compared with mild-moderate CDI and AAD (23.2%, n = 112 vs. 8.1%, n = 223 P < 0.001; vs. 11.9%, p = 0.018). Severe CDI was found to be an independent risk factor for subsequent systemic MDRO infection via logistic regression.ConclusionSevere CDI disease is associated with an increased risk of systemic MDRO infections.Disclosures All authors: No reported disclosures.

2849. Gut Microbiota Differences at the Time of Medical Intensive Care Unit (MICU) Admission Are Associated with Acquisition of Multi-drug-Resistant Organisms (MDROs) Among Patients Not Already Colonized with an MDRO

BackgroundAmong hospitalized patients, underlying variation in gut microbiota may confer differential risk for gut MDRO acquisition.MethodsRectal swab samples were collected from patients ≤2 days of MICU admission and then daily in the 27-bed MICU of an acute care hospital in Chicago, IL over 1 year. Patients were screened for MDRO colonization by selective culture (see Figure 1 for MDRO types); those with ≥2 swabs and MICU stays ≥3 days were studied. Bacterial 16S rRNA gene amplicon sequences were used for microbiota analysis. Medical records were reviewed.ResultsIn preliminary analysis, 2,480 samples were collected from 627 patients who acquired 170 MDROs (Figure 1). Debilitation, co-morbidities, and certain medical devices were associated with MDRO acquisition, though admission MDRO status was not (table). While no interactions were detected between admission MDRO status and clinical predictors of MDRO acquisition, there were significant differences in gut microbiota composition at the time of MICU admission between patients colonized with an MDRO on admission and those not colonized (P < 0.001, using analysis of molecular variance (AMOVA) on distances). Therefore, we stratified our analysis by admission MDRO colonization status. For patients MDRO-colonized at admission, there were no significant differences in microbiota of patients who later did or did not acquire a new MDRO (AMOVA P-value = 0.32). For patients not MDRO-colonized on admission, there was a significant difference in microbiota of patients who later acquired an MDRO and those who did not (AMOVA P-value: 0.026). Differentially abundant operational taxonomic units (OTUs, based on 3% sequence difference) included OTUs classified as Anaerococcus and as other Clostridiales (higher in patients who remained uncolonized) and as Enterococcus (higher in patients who acquired an MDRO) (Figure 2). Diversity was also higher in patients who remained uncolonized (Wilcoxon test P-value: 0.035) (Figure 3).ConclusionAmong patients not already colonized with an MDRO on admission, we identified gut microbiota differences associated with MDRO acquisition that could help explain patient-level variation in MDRO colonization resistance. Disclosures All Authors: No reported Disclosures.

894. Universal Decolonization in Nursing Homes: Effect of Chlorhexidine and Nasal Povidone–Iodine on Prevalence of Multi-Drug-Resistant Organisms (MDROs) in the PROTECT Trial

BackgroundThe prevalence of MDROs in nursing homes (NH) is much higher than that of hospitals. Decolonization to reduce the reservoir of MDRO carriage in NH residents may be a strategy to address MDRO spread within and among healthcare facilities.MethodsPROTECT is an 18-month cluster randomized trial of 1:1 universal decolonization vs. routine care in 28 NHs in California. Decolonization consists of chlorhexidine (CHG) bathing plus twice daily nasal iodophor on admission and Monday–Friday biweekly. We assessed pre- vs. post-intervention MDRO prevalence by sampling 50 randomly selected residents at each NH as an outcome unrelated to the trial’s primary intent (infection, hospitalization reduction). NH residents had nasal swabs cultured for methicillin-resistant S. aureus (MRSA), and skin (axilla/groin) swabs taken for MRSA, vancomycin-resistant Enterococcus (VRE), extended-spectrum β-lactamase producers (ESBL), and carbapenem-resistant Enterobacteriaceae (CRE). Generalized linear mixed models (GLM) assessed the difference in differences of MDRO prevalence using an arm by period interaction term, clustering by NH.ResultsFour NHs dropped from the trial. Among the 24 NHs that remained, MDRO colonization at baseline was 49.4% and 47.5% of residents in control (N = 650) vs. decolonization (N = 550) NHs, with no difference in MRSA, VRE, ESBL, and CRE (Table 1). Among remaining NHs, decolonization was associated with 28.8% raw decrease in MDRO prevalence in decolonization sites (GLM OR = 0.51, P < 0.001), 24.3% raw decrease in MRSA (OR = 0.66, P = 0.03), 61.0% raw decrease in VRE (OR = 0.17, P < 0.001), and 51.9% raw decrease in ESBL (OR = 0.40, P < 0.001). CRE increased, but numbers were small (Control arm: 10 in baseline, 4 in intervention; intervention arm: 1 in baseline, 2 in intervention, P = NS).ConclusionUniversal NH decolonization with CHG bathing and nasal iodophor resulted in a marked decrease in Gram-positive and Gram-negative MDRO prevalence. This decrease may lower MDRO acquisition, infection, and antibiotic use within NHs, as well as regional MDRO spread to other healthcare facilities. Disclosures All Authors: No reported Disclosures.