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AbstractBackground:A substantial proportion of patients undergoing hemodialysis carry Staphylococcus aureusin their noses, and carriers are at increased risk of S. aureusbloodstream infections. Our pragmatic clinical trial implemented nasal povidone-iodine (PVI) decolonization for the prevention of bloodstream infections in the novel setting of hemodialysis units.Objective:We aimed to identify pragmatic strategies for implementing PVI decolonization among patients in outpatient hemodialysis units.Design:Qualitative descriptive study.Setting:Outpatient hemodialysis units affiliated with five US academic medical centers. Units varied in size, patient demographics, and geographic location.Interviewees:Sixty-six interviewees including nurses, hemodialysis technicians, research coordinators, and other personnel.Methods:We conducted interviews with personnel affiliated with all five academic medical centers and conducted thematic analysis of transcripts.Results:Hemodialysis units had varied success with patient recruitment, but interviewees reported that patients and healthcare personnel (HCP) found PVI decolonization acceptable and feasible. Leadership support, HCP engagement, and tailored patient-focused tools or strategies facilitated patient engagement and PVI implementation. Interviewees reported both patients and HCP sometimes underestimated patients’ infection risks and experienced infection-prevention fatigue. Other HCP barriers included limited staffing and poor staff engagement. Patient barriers included high health burdens, language barriers, memory issues, and lack of social support.Conclusion:Our qualitative study suggests that PVI decolonization would be acceptable to patients and clinical personnel, and implementation is feasible for outpatient hemodialysis units. Hemodialysis units could facilitate implementation by engaging unit leaders, patients and personnel, and developing education for patients about their infection risk.

AbstractObjective:To assess whether measurement and feedback of chlorhexidine gluconate (CHG) skin concentrations can improve CHG bathing practice across multiple intensive care units (ICUs).Design:A before-and-after quality improvement study measuring patient CHG skin concentrations during 6 point-prevalence surveys (3 surveys each during baseline and intervention periods).Setting:The study was conducted across 7 geographically diverse ICUs with routine CHG bathing.Participants:Adult patients in the medical ICU.Methods:CHG skin concentrations were measured at the neck, axilla, and inguinal region using a semiquantitative colorimetric assay. Aggregate unit-level CHG skin concentration measurements from the baseline period and each intervention period survey were reported back to ICU leadership, which then used routine education and quality improvement activities to improve CHG bathing practice. We used multilevel linear models to assess the impact of intervention on CHG skin concentrations.Results:We enrolled 681 (93%) of 736 eligible patients; 92% received a CHG bath prior to survey. At baseline, CHG skin concentrations were lowest on the neck, compared to axillary or inguinal regions (P< .001). CHG was not detected on 33% of necks, 19% of axillae, and 18% of inguinal regions (P< .001 for differences in body sites). During the intervention period, ICUs that used CHG-impregnated cloths had a 3-fold increase in patient CHG skin concentrations as compared to baseline (P< .001).Conclusions:Routine CHG bathing performance in the ICU varied across multiple hospitals. Measurement and feedback of CHG skin concentrations can be an important tool to improve CHG bathing practice.

AbstractWe assessed susceptibility patterns to newer antimicrobial agents among clinical carbapenem-resistant Klebsiella pneumoniae(CRKP) isolates from patients in long-term acute-care hospitals (LTACHs) from 2014 to 2015. Meropenem-vaborbactam and imipenem-relebactam nonsusceptibility were observed among 9.9% and 9.1% of isolates, respectively. Nonsusceptibility to ceftazidime-avibactam (1.1%) and plazomicin (0.8%) were uncommon.

AbstractWe prospectively surveyed SARS-CoV-2 RNA contamination in staff common areas within an acute-care hospital. An increasing prevalence of surface contamination was detected over time. Adjusting for patient census or community incidence of coronavirus disease 2019 (COVID-19), the proportion of contaminated surfaces did not predict healthcare worker COVID-19 infection on study units.

AbstractBackground:The spatial and temporal extent of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) environmental contamination has not been precisely defined. We sought to elucidate contamination of different surface types and how contamination changes over time.Methods:We sampled surfaces longitudinally within COVID-19 patient rooms, performed quantitative RT-PCR for the detection of SARS-CoV-2 RNA, and modeled distance, time, and severity of illness on the probability of detecting SARS-CoV-2 using a mixed-effects binomial model.Results:The probability of detecting SARS-CoV-2 RNA in a patient room did not vary with distance. However, we found that surface type predicted probability of detection, with floors and high-touch surfaces having the highest probability of detection: floors (odds ratio [OR], 67.8; 95% credible interval [CrI], 36.3–131) and high-touch elevated surfaces (OR, 7.39; 95% CrI, 4.31–13.1). Increased surface contamination was observed in room where patients required high-flow oxygen, positive airway pressure, or mechanical ventilation (OR, 1.6; 95% CrI, 1.03–2.53). The probability of elevated surface contamination decayed with prolonged hospitalization, but the probability of floor detection increased with the duration of the local pandemic wave.Conclusions:Distance from a patient’s bed did not predict SARS-CoV-2 RNA deposition in patient rooms, but surface type, severity of illness, and time from local pandemic wave predicted surface deposition.

AbstractBackground:Multidrug-resistant organisms (MDROs) colonizing the healthcare environment have been shown to contribute to risk for healthcare-associated infections (HAIs), with adverse effects on patient morbidity and mortality. We sought to determine how bacterial contamination and persistent MDRO colonization of the healthcare environment are related to the position of patients and wastewater sites.Methods:We performed a prospective cohort study, enrolling 51 hospital rooms at the time of admitting a patient with an eligible MDRO in the prior 30 days. We performed systematic sampling and MDRO culture of rooms, as well as 16S rRNA sequencing to define the environmental microbiome in a subset of samples.Results:The probability of detecting resistant gram-negative organisms, including Enterobacterales, Acinetobacterspp, and Pseudomonasspp, increased with distance from the patient. In contrast, Clostridioides difficileand methicillin-resistant Staphylococcus aureuswere more likely to be detected close to the patient. Resistant Pseudomonasspp and S. aureuswere enriched in these hot spots despite broad deposition of 16S rRNA gene sequences assigned to the same genera, suggesting modifiable factors that permit the persistence of these MDROs.Conclusions:MDRO hot spots can be defined by distance from the patient and from wastewater reservoirs. Evaluating how MDROs are enriched relative to bacterial DNA deposition helps to identify healthcare micro-environments and suggests how targeted environmental cleaning or design approaches could prevent MDRO persistence and reduce infection risk.

AbstractMultiple guidelines recommend discontinuation of prophylactic antibiotics <24 hours after surgery. In a multicenter, retrospective cohort of 2,954 mastectomy patients ± immediate breast reconstruction, we found that utilization of prophylactic postdischarge antibiotics varied dramatically at the surgeon level among general surgeons and was virtually universal among plastic surgeons.

AbstractObjective:Despite recommendations to discontinue prophylactic antibiotics after incision closure or <24 hours after surgery, prophylactic antibiotics are continued after discharge by some clinicians. The objective of this study was to determine the prevalence and factors associated with postdischarge prophylactic antibiotic use after spinal fusion.Design:Multicenter retrospective cohort study.Patients:This study included patients aged ≥18 years undergoing spinal fusion or refusion between July 2011 and June 2015 at 3 sites. Patients with an infection during the surgical admission were excluded.Methods:Prophylactic antibiotics were identified at discharge. Factors associated with postdischarge prophylactic antibiotic use were identified using hierarchical generalized linear models.Results:In total, 8,652 spinal fusion admissions were included. Antibiotics were prescribed at discharge in 289 admissions (3.3%). The most commonly prescribed antibiotics were trimethoprim/sulfamethoxazole (22.1%), cephalexin (18.8%), and ciprofloxacin (17.1%). Adjusted for study site, significant factors associated with prophylactic discharge antibiotics included American Society of Anesthesiologists (ASA) class ≥3 (odds ratio [OR], 1.31; 95% CI, 1.00–1.70), lymphoma (OR, 2.57; 95% CI, 1.11–5.98), solid tumor (OR, 3.63; 95% CI, 1.62–8.14), morbid obesity (OR, 1.64; 95% CI, 1.09–2.47), paralysis (OR, 2.38; 95% CI, 1.30–4.37), hematoma/seroma (OR, 2.93; 95% CI, 1.17–7.33), thoracic surgery (OR, 1.39; 95% CI, 1.01–1.93), longer length of stay, and intraoperative antibiotics.Conclusions:Postdischarge prophylactic antibiotics were uncommon after spinal fusion. Patient and perioperative factors were associated with continuation of prophylactic antibiotics after hospital discharge.

AbstractObjectiveResistance to extended-spectrum cephalosporins (ESC) among Enterobacteriaceae (EB) is increasingly prevalent. We sought to determine the clinical outcomes associated with community-onset ESC-resistant (ESC-R) EB urinary tract infections (UTIs) in a US health system.DesignRetrospective cohort study.PatientsAll patients presenting to the emergency departments (EDs) or outpatient practices with EB UTIs between 2010 and 2013 were included. Exposed patients had ESC-R EB UTIs. Unexposed patients had ESC-susceptible EB UTIs and were matched to exposed subjects 1:1 on study year. Multivariable logistic regression analyses were performed to evaluate the association between ESC-R EB UTI and the outcomes of clinical failure and inappropriate initial antibiotic therapy (IIAT).ResultsA total of 302 patients with community-onset EB UTI were included, with 151 exposed and unexposed. On multivariable analyses, UTI due to an ESC-R EB was significantly associated with clinical failure (odds ratio [OR], 7.07; 95% confidence interval [CI], 3.16–15.82; P<.01). Other independent risk factors for clinical failure included infection with Citrobacterspp and need for hemodialysis. UTI due to an ESC-R EB was also significantly associated with IIAT (OR, 4.40; 95% CI, 2.64–7.33; P<.01).ConclusionsCommunity-onset UTI due to an ESC-R EB organism is significantly associated with clinical failure, which may be due in part to IIAT. Further studies are needed to determine which patients in the community are at high risk for drug-resistant infection to help inform prompt diagnosis and appropriate antibiotic prescribing for ESC-R EB.

In a cohort of inpatients with hematologic malignancy and positive enzyme immunoassay (EIA) or polymerase chain reaction (PCR) Clostridium difficiletests, we found that clinical characteristics and outcomes were similar between these groups. The method of testing is unlikely to predict infection in this population, and PCR-positive results should be treated with concern.Infect Control Hosp Epidemiol2018;863–866

OBJECTIVETo evaluate risk factors for and molecular characteristics of community-onset extended-spectrum cephalosporin-resistant (ESC-R) Enterobacteriaceae (EB) urinary tract infections (UTIs) in a US health system.DESIGNCase-control study.PARTICIPANTSAll patients presenting to the emergency department or outpatient practices with EB UTIs from December 21, 2010, through April 22, 2013, were included. Case patients had ESC-R EB UTIs. Control patients had ESC-susceptible EB UTIs and were matched 1:1 on study year.METHODSRisk factors for ESC-R EB UTI were assessed using multivariable conditional logistic regression. A subset of case isolates was evaluated for extended-spectrum beta-lactamases.RESULTSA total of 302 patients with community-onset EB UTI were included, of which 151 were cases. On multivariable analysis, risk factors for ESC-R EB UTI included trimethoprim-sulfamethoxazole use in the prior 6 months (odds ratio, 2.40 [95% CI, 1.22–4.70]; P=.01), older age (1.03 [1.01–1.04]; P<.001), diabetes (2.91 [1.32–6.41]; P=.008), and presentation to the emergency department ( 2.42 [1.31–4.46]; P=.005). The prevalence of extended-spectrum beta-lactamases among 120 case isolates was 52% CTX-M, 29% TEM, 20% OXA, and 13% SHV. The prevalence of AmpC was 25%. Pulsed-field gel electrophoresis of the CTX-M Escherichia coliisolates showed no distinct clusters.CONCLUSIONSUse of trimethoprim-sulfamethoxazole, older age, diabetes, and presentation to the emergency department were associated with community-onset ESC-R EB UTI. There was a high prevalence of CTX-M among our community isolates. Further studies are needed to determine strategies to limit emergence of these organisms in the community.Infect Control Hosp Epidemiol2016;1433–1439

OBJECTIVETo determine the impact of total household decolonization with intranasal mupirocin and chlorhexidine gluconate body wash on recurrent methicillin-resistant Staphylococcus aureus(MRSA) infection among subjects with MRSA skin and soft-tissue infection.DESIGNThree-arm nonmasked randomized controlled trial.SETTINGFive academic medical centers in Southeastern Pennsylvania.PARTICIPANTSAdults and children presenting to ambulatory care settings with community-onset MRSA skin and soft-tissue infection (ie, index cases) and their household members.INTERVENTIONEnrolled households were randomized to 1 of 3 intervention groups: (1) education on routine hygiene measures, (2) education plus decolonization without reminders (intranasal mupirocin ointment twice daily for 7 days and chlorhexidine gluconate on the first and last day), or (3) education plus decolonization with reminders, where subjects received daily telephone call or text message reminders.MAIN OUTCOME MEASURESOwing to small numbers of recurrent infections, this analysis focused on time to clearance of colonization in the index case.RESULTSOf 223 households, 73 were randomized to education-only, 76 to decolonization without reminders, 74 to decolonization with reminders. There was no significant difference in time to clearance of colonization between the education-only and decolonization groups (log-rank P=.768). In secondary analyses, compliance with decolonization was associated with decreased time to clearance (P=.018).CONCLUSIONSTotal household decolonization did not result in decreased time to clearance of MRSA colonization among adults and children with MRSA skin and soft-tissue infection. However, subjects who were compliant with the protocol had more rapid clearanceTrial registration. ClinicalTrials.gov identifier: NCT00966446Infect Control Hosp Epidemiol2016;1–8

OBJECTIVETo identify risk factors for recurrent methicillin-resistant Staphylococcus aureus(MRSA) colonization.DESIGNProspective cohort study conducted from January 1, 2010, through December 31, 2012.SETTINGFive adult and pediatric academic medical centers.PARTICIPANTSSubjects (ie, index cases) who presented with acute community-onset MRSA skin and soft-tissue infection.METHODSIndex cases and all household members performed self-sampling for MRSA colonization every 2 weeks for 6 months. Clearance of colonization was defined as 2 consecutive sampling periods with negative surveillance cultures. Recurrent colonization was defined as any positive MRSA surveillance culture after clearance. Index cases with recurrent MRSA colonization were compared with those without recurrence on the basis of antibiotic exposure, household demographic characteristics, and presence of MRSA colonization in household members.RESULTSThe study cohort comprised 195 index cases; recurrent MRSA colonization occurred in 85 (43.6%). Median time to recurrence was 53 days (interquartile range, 36–84 days). Treatment with clindamycin was associated with lower risk of recurrence (odds ratio, 0.52; 95% CI, 0.29–0.93). Higher percentage of household members younger than 18 was associated with increased risk of recurrence (odds ratio, 1.01; 95% CI, 1.00–1.02). The association between MRSA colonization in household members and recurrent colonization in index cases did not reach statistical significance in primary analyses.CONCLUSIONA large proportion of patients initially presenting with MRSA skin and soft-tissue infection will have recurrent colonization after clearance. The reduced rate of recurrent colonization associated with clindamycin may indicate a unique role for this antibiotic in the treatment of such infection.Infect. Control Hosp. Epidemiol.2015;36(7):786–793

Objective.Infections due to fluoroquinolone-resistant Escherichia coli(FQREC) are associated with significant morbidity and mortality. Fluoroquinolone resistance likely arises at the level of gastrointestinal colonization. The objective of this study was to identify risk factors for the development of FQREC gastrointestinal tract colonization in hospitalized patients, including the impact of antibiotics prescribed during hospitalization.Design.A prospective cohort study was conducted from 2002 to 2004 within a university health system.Methods.Hospitalized patients initially colonized with fluoroquinolone-susceptible E. coliwere followed up with serial fecal sampling for new FQREC colonization or until hospital discharge or death. A Cox proportional hazards regression model was developed to identify risk factors for new FQREC colonization, with antibiotic exposure modeled as time-varying covariates.Results.Of 395 subjects, 73 (18.5%) became newly colonized with FQREC. Length of stay before sampling (hazard ratio [HR], 1.02 [95% confidence interval (CI), 1.1–1.03]; P= .003) and malignancy (HR, 0.37 [95% CI, 0.21–0.67]; P= .001) were significantly associated with the development of FQREC colonization. In addition, receipt of a first-generation cephalosporin (HR, 1.19 [95% CI, 1.10–1.29]; P<.001) or cefepime (HR, 1.05 [95% CI, 1.00–1.10]; P= .048) during hospitalization increased the risk of new FQREC colonization.Conclusions.The acquisition of FQREC in the hospital setting is complex, and antimicrobial stewardship programs should take into account patterns of antibiotic use in implementing strategies to reduce the development of new FQREC colonization. Future studies are needed to identify risk factors for infection in hospitalized patients newly colonized with FQREC.

Objective.Comparison of studies evaluating patient-to-patient transmission of organisms is difficult, given the lack of standardized criteria. We used fluoroquinolone-resistant Escherichia coli(FQREC) as a model to characterize variability in definitions of relatedness across studies and to evaluate the resultant impact on study conclusions.Design.Narrative review and cohort study.Methods.The narrative review compared relatedness criteria across studies of FQREC. Additionally, an existing database was used to compare relatedness of isolates on the basis of molecular criteria alone versus molecular plus clinical criteria with different temporal cutoffs (hospitalization overlap of =1 day or allowance for nonoverlap of hospitalization dates of =7 days or =30 days).Results.Forty-six articles met narrative review inclusion criteria. Sixteen studies exclusively utilized molecular criteria to define relatedness. Thirty studies included molecular and clinical criteria. Of these, 6 included temporal data (ie, time period of isolate identification), 10 included patient location, and 14 included proximity and temporal criteria. For the database analysis, 353 patients were colonized with FQREC. There were 2 main clusters containing 48 and 17 related isolates within 49 pulsed-field gel electrophoresis types. Among the clusters, 18.4% of isolates were related by molecular criteria. Incorporating clinical criteria, fewer isolates were considered related: 5.7% of isolates using 30-day criteria, 3.1% using 7-day criteria, and 1.4% using 1-day overlap.Conclusions.There is considerable variability in definitions of relatedness of FQREC. Utilizing molecular criteria alone to define relatedness overestimates transmission compared with definitions including clinical criteria. Standard definitions of relatedness in studies of antimicrobial-resistant organisms are needed.

We describe the prevalence of and risk factors for colonization with extended-spectrum β-lactamase (ESBL)–producing Escherichia coliand Klebsiellaspecies (ESBL-EK) in hospitalized patients. The prevalence of colonization with ESBL-EK was 2.6%. Colonization was associated with cirrhosis, longer duration of hospital stay prior to surveillance, and prior exposure to clindamycin or meropenem.

We identified 1,805 gram-negative organisms in cultures of urine samples obtained over a 10-month period from residents of 63 long-term care facilities. The prevalence of fluoroquinolone resistance in Escherichia coliwas 51% (446 of 874 isolates), whereas the preva¬lences of ceftazidime and imipenem resistance in Klebsiellaspecies were 26% and 6% (84 and 19 of 323 isolates), respectively. The prevalence of resistance varied significantly by facility type, size, and geographic location.

Objective.The prevalence of fluoroquinolone (FQ) resistance in Escherichia colihas increased markedly in recent years. Despite the important role of gastrointestinal tract colonization with FQ-resistant E. coli(FQREC), the prevalence of and risk factors for FQREC colonization among the general hospitalized patient population have not been described, to our knowledge. The objective of this study was to identify the prevalence of and risk factors for FQREC colonization among hospitalized patients.Design.Three-year case-control study. Case patients (ie, all subjects with FQREC colonization) were compared with control patients (ie, all subjects without FQREC colonization).Setting.Two large medical centers within an academic health system.Participants.All patients hospitalized at the 2 study hospitals.Main Outcome Measure.Three annual fecal surveillance surveys were conducted. All patients colonized with FQREC (levofloxacin minimum inhibitory concentration, ≥ 8 μg/mL) were identified.Results.Of the 774 subjects, 89 (11.5%) were colonized with FQREC. Although there was a significant association between prior FQ use and FQREC colonization on bivariable analysis (odds ratio [OR], 2.02 [95% confidence interval {CI}, 1.14–3.46]; P= .01), there was statistically significant effect modification by year of study (P= .005). In multivariable analyses, after controlling for the hospital and for the duration of hospitalization prior to sampling, the association between FQ use and FQREC colonization was as follows: adjusted OR (aOR), 0.97 (95% CI, 0.29–3.23) in 2002; aOR, 1.41 (95% CI, 0.57–3.50) in 2003; and aOR, 9.87 (95% CI, 3.67–26.55) in 2004.Conclusions.The association between prior FQ use and FQREC colonization varied significantly by study year, suggesting that the clinical epidemiology of resistant organisms may change over time. Furthermore, in the context of recent work showing significant changes in FQREC prevalence as well as changes in FQ resistance mechanisms (specifically, efflux overexpression) over the same time period, these results suggest a previously unrecognized complexity in the relationship between the clinical and molecular epidemiology of FQ resistance.

Background.A number of recent studies of antimicrobial resistance have focused on the role of antimicrobial-resistant pathogens that colonize the gastrointestinal tract. However, participation rates have been low in studies that involve fecal sampling. Attitudes toward such studies among potential study participants have not been assessed.Methods.We conducted a cross-sectional survey, enrolling 3 groups of inpatients from a large academic center. Group 1 consisted of patients who had previously participated in a cohort study of fluoroquinolone-resistant Escherichia coli, which involved the collection of perirectal swab samples. Group 2 consisted of patients who had previously refused to participate in the study of fluoroquinolone-resistant E. coli. Group 3 consisted of patients who had never been asked to participate in the study of the fluoroquinolone-resistant E. coli. The survey assessed patients' attitudes and beliefs regarding medical research and their willingness to consent to collection of a perirectal swab sample. Response options were recorded on a 5-point Likert scale. The Fisher exact test was used to compare dichotomized responses across study groups.Results.A total of 90 patients were surveyed: there were 29 in group 1 and in group 2 and 32 in group 3. Of 90 patients, 31 (35%) believed researchers might run additional tests on collected samples without informing the patient, whereas 25 (27%) believed persons other than the research team might gain access to study results. The belief that a person could get sicker as a result of a having a perirectal swab sample collected was significantly more common among patients who had previously refused to participate in the fluoroquinolone-resistant E. colistudy.Conclusion.This study highlights important beliefs and attitudes that are associated with the likelihood of participating in studies of antimicrobial resistance. Explicitly addressing these concerns with eligible patients is critical to optimize participation in future studies.

Background:Clinically diagnosed ventilator-associated pneumonia (VAP) is common in the long-term acute-care hospital (LTACH) setting and may contribute to adverse ventilator-associated events (VAEs). Pseudomonas aeruginosais a common causative organism of VAP. We evaluated the impact of respiratory P. aeruginosacolonization and bacterial community dominance, both diagnosed and undiagnosed, on subsequent P. aeruginosaVAP and VAE events during long-term acute care. Methods:We enrolled 83 patients on LTACH admission for ventilator weaning, performed longitudinal sampling of endotracheal aspirates followed by 16S rRNA gene sequencing (Illumina HiSeq), and bacterial community profiling (QIIME2). Statistical analysis was performed with R and Stan; mixed-effects models were fit to relate the abundance of respiratory Psaon admission to clinically diagnosed VAP and VAE events. Results:Of the 83 patients included, 12 were diagnosed with P. aeruginosapneumonia during the 14 days prior to LTACH admission (known P. aeruginosa), and 22 additional patients received anti–P. aeruginosaantibiotics within 48 hours of admission (suspected P. aeruginosa); 49 patients had no known or suspected P. aeruginosa(unknown P. aeruginosa). Among the known P. aeruginosagroup, all 12 patients had P. aeruginosadetectable by 16S sequencing, with elevated admission P. aeruginosaproportional abundance (median, 0.97; IQR, 0.33–1). Among the suspected P. aeruginosagroup, all 22 patients had P. aeruginosadetectable by 16S sequencing, with a wide range of admission P. aeruginosaproportional abundance (median, 0.0088; IQR, 0.00012–0.31). Of the 49 patients in the unknown group, 47 also had detectable respiratory Psa, and many had high P. aeruginosaproportional abundance at admission (median, 0.014; IQR, 0.00025–0.52). Incident P. aeruginosaVAP was observed within 30 days in 4 of the known P. aeruginosapatients (33.3%), 5 of the suspected P. aeruginosapatients (22.7%), and 8 of the unknown P. aeruginosapatients (16.3%). VAE was observed within 30 days in 1 of the known P. aeruginosapatients (8.3%), 2 of the suspected P. aeruginosapatients (9.1%), and 1 of the unknown P. aeruginosapatients (2%). Admission P. aeruginosaabundance was positively associated with VAP and VAE risk in all groups, but the association only achieved statistical significance in the unknown group (type S error <0.002 for 30-day VAP and <0.011 for 30-day VAE). Conclusions:We identified a high prevalence of unrecognized respiratory P. aeruginosacolonization among patients admitted to LTACH for weaning from mechanical ventilation. The admission P. aeruginosaproportional abundance was strongly associated with increased risk of incident P. aeruginosaVAP among these patients.Funding:NoneDisclosures:None

Background: Healthcare exposure results in significant microbiome disruption, particularly in the setting of critical illness, which may contribute to risk for healthcare-associated infections (HAIs). Patients admitted to long-term acute-care hospitals (LTACHs) have extensive prior healthcare exposure and critical illness; significant microbiome disruption has been previously documented among LTACH patients. We compared the predictive value of 3 respiratory tract microbiome disruption indices—bacterial community diversity, dominance, and absolute abundance—as they relate to risk for ventilator-associated pneumonia (VAP) and adverse ventilator-associated events (VAE), which commonly complicate LTACH care. Methods: We enrolled 83 subjects on admission to an academic LTACH for ventilator weaning and performed longitudinal sampling of endotracheal aspirates, followed by 16S rRNA gene sequencing (Illumina HiSeq), bacterial community profiling (QIIME2) for diversity, and 16S rRNA quantitative PCR (qPCR) for total bacterial abundance. Statistical analyses were performed with R and Stan software. Mixed-effects models were fit to relate the admission MDIs to subsequent clinically diagnosed VAP and VAE. Results: Of the 83 patients, 19 had been diagnosed with pneumonia during the 14 days prior to LTACH admission (ie, “recent past VAP”); 23 additional patients were receiving antibiotics consistent with empiric VAP therapy within 48 hours of admission (ie, “empiric VAP therapy”); and 41 patients had no evidence of VAP at admission (ie, “no suspected VAP”). We detected no statistically significant differences in admission Shannon diversity, maximum amplicon sequence variant (ASV)–level proportional abundance, or 16S qPCR across the variables of interest. In isolation, all 3 admission microbiome disruption indices showed poor predictive performance, though Shannon diversity performed better than maximum ASV abundance. Predictive models that combined (1) bacterial diversity or abundance with (2) recent prior VAP diagnosis and (3) concurrent antibiotic exposure best predicted 14-day VAP (type S error < 0.05) and 30-day VAP (type S error < 0.003). In this cohort, VAE risk was paradoxically associated with higher admission Shannon diversity and lower admission maximum ASV abundance. Conclusions: In isolation, respiratory tract microbiome disruption indices obtained at LTACH admission showed poor predictive performance for subsequent VAP and VAE. But diversity and abundance models incorporating recent VAP history and admission antibiotic exposure performed well predicting 14-day and 30-day VAP.Disclosures:NoneFunding:None

A case-control study to determine risk factors for clinical infection with Escherichia coliwas conducted among nursing home residents colonized with fluoroquinolone-resistant E. coli. Among 94 subjects, 11 (12%) developed infections with E. coli. Risk factors included the presence of a urinary catheter or tracheostomy, diabetes mellitus, and trimethoprim-sulfamethoxazole exposure.Infect Control Hosp Epidemiol2015;00(0): 1–3

We describe the prevalence of and risk factors for colonization with extended-spectrum (3-lactamase-producing Enterobacteriaceae (ESBL-EB) in the long-term care facility (LTCF) setting. Colonization prevalence differed significantly across the 3 LTCFs evaluated in the study, with recent use of levofloxacin and fecal incontinence demonstrating borderline significant associations with ESBL-EB colonization.Infect Control Hosp Epidemiol2012;33(3):302-304

Data from a case-control study were used to derive and internally validate a prediction rule for identifying fluoroquinolone resistance in healthcare-acquired gram-negative urinary tract infection. This prediction rule has an excellent sensitivity and specificity (C-statistic, 0.816). External validation is necessary before implementing this rule to optimize empirical antibiotic use in clinical practice.

Of 49 long-term care facility residents, 21 (43%) were colonized with 2 or more distinct strains of Escherichia coli.There were no significant risk factors for colonization with multiple strains of E. coli.These results suggest that future efforts to efficiently identify the diversity of colonizing strains will be challenging.

We studied provider- and patient-collected samples from multiple anatomic sites to determine the yield for detection of methicillin-resistant Staphylococcus aureus(MRSA). Sampling of multiple sites was required to achieve a sensitivity of more than 90% for MRSA colonization. Groin and perineum samples yielded positive results significantly more often for community-onset MRSA than for hospital-onset MRSA. Agreement rates between provider- and patient-collected swab specimens were excellent.

We assessed the rate of recovery of fluoroquinolone-resistant and fluoroquinolone-susceptible Escherichia coliisolates from culture of frozen perirectal swab samples compared with the results for culture of the same specimen before freezing. Recovery rates for these 2 classes of E. coliwere 91% and 83%, respectively. The majority of distinct strains recovered from the initial sample were also recovered from the frozen sample. The strains that were not recovered were typically present only in low numbers in the initial sample. These findings emphasize the utility of frozen surveillance samples.

Background:Clostridioides difficileinfection (CDI) is a major contributor to morbidity and mortality in patients with hematologic malignancy. Due to both immunosuppression and frequent antibiotic exposures, up to one-third of inpatients receiving chemotherapy or stem-cell transplant develop CDI. Transmission of C. difficilein healthcare facilities occurs due to environmental surface contamination and hand carriage by healthcare workers from colonized and infected patients. We investigated the effectiveness of enhanced room cleaning in collaboration with environmental services (EVS) staff to prevent CDI transmission and infection.Methods: From April 1, 2018, to September 30, 2018, a multimodal enhanced cleaning intervention was implemented on 2 oncology units at the Hospital of the University of Pennsylvania. This intervention included real-time feedback to EVS staff following ATP bioluminescence monitoring. Additionally, all rooms on the intervention units underwent UV disinfection after terminal cleaning. We performed a system-level cohort study, comparing rates of CDI on the 2 study units to historic and 2 concurrent control units. Historic and concurrent control units received UV disinfection only for rooms with prior occupants with MRSA or CDI. All units during the intervention period received education on the importance of environmental cleaning for infection prevention. Mixed-effects Poisson regression was used to adjust for system-level confounders. Results: A median of 1.34 CDI cases per 1,000 patient days (IQR, 1.20–3.62) occurred during the 12-month baseline period. There was a trend toward a reduced rate of CDI across all units during the intervention period (median, 1.19; IQR, 0.00–2.47; P= .13) compared with all units during the historical period. Using mixed-effects Poisson regression, accounting for the random effects of study units, the intervention was associated with an incidence rate ratio for C. difficileof 0.72 compared to control units (95% CI, 0.53–0.97; P= .03). Average room turnaround time (TAT) increased across all units during the study period, from 78 minutes (IQR 74–81) to 92 minutes (IQR, 85–96; P< .001). Within the intervention period, TAT was higher on intervention units (median, 94 minutes; IQR, 92–98) compared to concurrent control units (median, 85; IQR, 80–92; P= .005). Conclusions: Enhanced environmental cleaning, including UV disinfection of all patient rooms and ATP bioluminescent monitoring with real-time feedback, was associated with a reduction in the incidence of CDI.Funding:NoneDisclosures:None