Surveillance Cultures Research Articles

Reducing the dosing frequency of selective digestive tract decontamination to three times daily provides effective decontamination of Gram-negative bacteria

This study evaluated the effectiveness of selective digestive tract decontamination (SDD) application three times daily (t.i.d.) compared to the standard four times daily (q.i.d.). Retrospective equivalence (combined non-inferiority and non-superiority design) study with a before-and-after design on a tertiary ICU in which the SDD frequency was reduced from q.i.d. to t.i.d. All patients with ICU admissions ≥72h and with ≥2 surveillance cultures collected on different dates were included in this study. We compared successful decontamination of Gram-negative bacteria (GNB). Furthermore, time to decontamination, ICU-acquired GNB bacteraemia and 28-day mortality were compared between the two groups. In total 1958 ICU admissions (1236 q.i.d., 722 t.i.d). Decontamination was achieved during the first week of admission in 77% and 76% of patients receiving SDD q.i.d and t.i.d., respectively. Successful decontamination within 14 days (without consecutive acquisition of Gram-negative bacteria) was achieved in 69.3% of the admissions with q.i.d. versus 66.8% in t.i.d. SDD (p-value = 0.2519). The proportions of successful decontamination of GNB were equivalent in both groups (−0.025, 98% CI: −0.087; 0.037). There was no significant difference in time to decontamination between the two regimens (log-rank test p-value = 0.55). Incidence (episodes/1000 days) of ICU-acquired GNB bacteraemia was 0.9 in both groups, and OR for death at day 28 in the t.i.d. group compared to the q.i.d. group was 0.99 (95% confidence interval, 0.80–1.21). This study shows that a t.i.d. application regimen achieves similar outcomes to the standard q.i.d. regime, for both microbiological and clinical outcome measures.

#74: Development of a Solid-Organ Transplant-Specific Antibiogram in a Tertiary Pediatric Hospital in Canada

Abstract Background Solid-organ transplant (SOT) patients are more vulnerable to infections by antimicrobial-resistant organisms (AROs) because of their hospital exposure, compromised immune systems, and antimicrobial exposure. Therefore, it may be useful for transplant facilities to create transplant-specific antibiograms to direct empirical antimicrobial regimens and monitor trends in antimicrobial resistance. Methods SOT (i.e., lung, liver, renal, and heart) antibiograms were created using antimicrobial susceptibility data on isolates from 2012 to 2018 at The Hospital for Sick Children, a tertiary pediatric hospital and transplant center in Toronto, Ontario. The Clinical Laboratory Standards Institute (CLSI) guidelines were followed to generate the antibiograms. The first clinical isolate of a species from a patient in each year was included irrespective of body site; duplicates were eliminated and surveillance cultures were excluded. Results from 2 years of data were pooled on a rolling basis to achieve an adequate sample size in both SOT and hospital-wide antibiogram. The SOT antibiogram was then compared with the hospital-wide antibiogram of the compatible 2 pooled years from 2012 to 2018. For subgroup analyses in the SOT population, organ-specific antibiograms and transplant timing-specific antibiograms (pretransplant, post-transplant <1 year, and post-transplant ≥1 year) between transplant and sample collection dates were analyzed. All proportions were compared using the χ 2 test. Results The top 5 organisms in one (2 year) analysis period of the SOT antibiogram were Escherichia coli (n = 29), Staphylococcus aureus (n = 28), Pseudomonas aeruginosa (n = 20), Enterobacter cloacae complex (n = 18), and Klebsiella pneumoniae (n = 17). For E.coli, susceptibility in the SOT antibiogram was significantly lower than those in the hospital-wide antibiogram in 2017/2018 for ampicillin (27% vs. 48%; P = 0.015), piperacillin/tazobactam (55% vs. 87%; P < 0.001), cefotaxime (59% vs. 88%; P < 0.001), ciprofloxacin (71% vs. 87%; P = 0.007) and cotrimoxazole (41% vs. 69%; P < 0.001), but not significantly different for gentamicin (94% vs. 91%; P = 0.490), tobramycin (88% vs. 90%; P = 0.701) and amikacin (100% vs. 99%; P = 0.558). These findings were consistent throughout the study period in E.coli. There was no statistically significant difference between the SOT and hospital-wide antibiograms for other organisms. There were no significant differences in susceptibility between organ-specific antibiograms or transplant timing-specific antibiograms in 2012–2018. Conclusions We found that E.coli from the SOT population had a significantly lower sensitivity to all antimicrobials, except aminoglycosides, compared with those from the hospital-wide population. Other organisms had similar susceptibility to the hospital-wide population. Developing a SOT antibiogram will assist in revising and improving empiric treatment guidelines for this population.

43745 A pilot survey to assess the practices, attitudes and beliefs around endotracheal aspirate culture use in a pediatric intensive care unit

ABSTRACT IMPACT: Optimizing the use of endotracheal aspirate cultures (EACs) has the potential to improve the care of complex mechanically ventilated children by improving testing practices and avoiding unnecessary antibiotic treatment for false-positive results. OBJECTIVES/GOALS: An electronic survey has previously been employed to characterize the practices and attitudes around blood cultures among critically ill children. The objective of this work was to develop and pilot a new survey as a tool to understand practices and attitudes that could inform quality improvement initiatives to optimize EAC practices. METHODS/STUDY POPULATION: Informed by prior experience of diagnostic stewardship of EAC in other settings and using a similar structure to the blood culture practice survey, we developed an electronic self-administered survey sent to respiratory therapists, advanced practice providers, and physicians at the Johns Hopkins All Children’s pediatric intensive care unit. RESULTS/ANTICIPATED RESULTS: A total of 27 of 87 clinicians (37%) responded to the survey (22 respiratory therapists, 9 attending physicians and 1 advanced practice provider). Responses indicated samples are typically collected by respiratory therapists via in-line (endotracheal) or open suctioning (tracheostomy). Most respondents did not feel EACs could lead to unintended negative consequences (71%), agreed practices vary between people (89%), and felt an algorithm would help align the clinical team (79%). Most respondents agreed some clinicians may be reluctant to change practice (82%) and may not change practice due to concern for missing diagnosis of ventilator-associated pneumonia or tracheitis (78%). Surveillance cultures were not used in this unit and there were no prior EAC diagnostic stewardship efforts. DISCUSSION/SIGNIFICANCE OF FINDINGS: This survey captured practices, perceptions and barriers to changes that will inform the implementation of quality improvement initiatives to optimize EAC use in this unit. Future studies can consider utilizing an electronic survey to describe practice variation, clinician believes and attitudes about EAC testing in ventilated patients.

Clinical significance of microbial colonization identified by initial bronchoscopy in patients with lung cancer requiring chemotherapy.

BackgroundThere are limited data on the association between bronchial colonization and respiratory infections in people with lung cancer requiring cytotoxic chemotherapy. We investigated whether bronchial colonization in initial bronchoscopy specimens can predict the development of pneumonia after chemotherapy in patients with lung cancer.MethodsFour hundred thirteen patients with lung cancer included in the Catholic Medical Center lung cancer registry were enrolled from March 2015 to August 2018. Demographic data, microbiology results, development of pneumonia after chemotherapy, and clinical information about lung cancer were analyzed retrospectively.ResultsA total of 206 lung cancer patients treated with chemotherapy were included in the analysis. Forty patients (19.4%) had positive results for the bronchial washing culture during the initial evaluation of lung cancer. The most common organisms were Klebsiella pneumoniae (n=14) and Streptococcus pneumoniae (n=6) in the surveillance culture, and Pneumocystis jirovecii (n=12) and Staphylococcus aureus (n=8) at the time of pneumonia development. Eighty-nine patients (43.2%) had pneumonia after chemotherapy, but the occurrence of pneumonia did not differ according to the colonization. There were no patients for whom the initial isolated organism was a causative microbe for the development of pneumonia after or during chemotherapy. The pneumonia group had poorer prognosis than the non-pneumonia group (378 vs. 705 days, P=0.0004).ConclusionsMicrobial colonization in bronchoscopy specimens was not associated with pneumonia development or mortality after chemotherapy for lung cancer. This finding suggests that testing surveillance culture may not be helpful for predicting pneumonia or improving survival in lung cancer patients with chemotherapy.

Carbapenem-resistant Enterobacteriaceae among kidney transplant recipients – insights on the risk of acquisition and CRE infection

Background Kidney transplant recipients are a risk group for carbapenem-resistant Enterobacteriaceae infection. Objectives This study aimed to identify risk factors for CRE acquisition and infection among kidney transplant recipients. Methods We conducted a case-control study; we defined the case as kidney transplant recipient with positive culture for carbapenem-resistant Enterobacteriaceae identified between January 2010 and February 2019. Controls were chosen among kidney transplant recipients hospitalized in the same period of cases (1:2). Surveillance culture for carbapenem-resistant Enterobacteriaceae was performed at admission and weekly during hospital stay. The risk factors analysis for carbapenem-resistant Enterobacteriaceae infection was performed among patients colonized by these bacteria. Results We identified 331 patients colonized with carbapenem-resistant Enterobacteriaceae; The median time from transplantation to first carbapenem-resistant Enterobacteriaceae positive culture was 42 days (range from 3 to 7399 days); 125(37.8%) patients developed infection; the most common site was urinary tract. Risk factors for carbapenem-resistant Enterobacteriaceae acquisition were recipient age >45-year, diabetes nephropathy, donor age >55-year, ureteral stent at kidney transplantation, delay of graft function, median lymphocytes count <800cells/mm3, and acute cellular rejection. Risk factors for carbapenem-resistant Enterobacteriaceae infection were recipient age at CRE acquisition >50-year; median lymphocytes count ≤700 cells/mm3, carbapenem use, and colonization by polymyxin-resistant strain. Patients colonized by polymyxin and carbapenem resistant Enterobacteriaceae strain who used carbapenem had a 93.8% probability of developing infection by this agent. Conclusion Carbapenem-resistant Enterobacteriaceae acquisition after kidney transplant is related to graft conditions, immunosuppression degree. Among carbapenem-resistant Enterobacteriaceae colonized patients, special attention is needed for those harbouring polymyxin-resistant strains.

Reconceptualizing Assistance for Young Children of Color With Disabilities in an Inclusion Classroom

In this article, we draw on DisCrit to critically analyze how a group of early childhood educators approached assistance with young children of color with disabilities in a Head Start inclusion classroom. Using examples from data collected over one school year, we demonstrate how child-centered assistance advances justice for young children of color with disabilities who are often subjected to a surveillance culture in schools. We critique assistance that aligns with the medical model of disability and aims to change young children of color with disabilities to conform to ableist, racist expectations of schooling. We offer examples of assistance practices that contrastingly aim to support young children of color with disabilities to pursue their own interests and purposes. Through these counterstories, we reconceptualize assistance as a practice that can support young children of color with disabilities to be more fully themselves.

To share or not to share? That is the (social media) dilemma. Expectant mothers questioning and making sense of performing pregnancy on social media

Posting about one’s pregnancy on social media has become a common practice for many expectant mothers in the global North. However, social media sharing implies transcending the conventional time and space boundaries of interpersonal communication. As such, women may feel ill at ease when deciding whether and how to narrate their journey online. This article examines mothers’ pre-birth social media dilemmas via a thematic analysis of 1237 posts from 26 threads on a parenting forum in which expectant mothers discussed their doubts and fears about sharing their pregnancy on social media. The dilemmatic dimension of social media sharing challenges the simplistic idea that sharenting is a practice most women naively adhere to without question. Indeed, the present research shows that online posters face dilemmas about performing their pregnancies on social media and collectively learn to make sense of and question a culture of surveillance, while reclaiming their self-representational agency in the process.

Rapid Spread and Control of Multidrug-Resistant Gram-Negative Bacteria in COVID-19 Patient Care Units.

We describe rapid spread of multidrug-resistant gram-negative bacteria among patients in dedicated coronavirus disease care units in a hospital in Maryland, USA, during May–June 2020. Critical illness, high antibiotic use, double occupancy of single rooms, and modified infection prevention practices were key contributing factors. Surveillance culturing aided in outbreak recognition and control.

Epidemiology of and risk factors for mortality due to carbapenemase-producing organisms (CPO) in healthcare facilities

SummaryBackgroundCarbapenemase-producing organisms (CPO) have been largely responsible for the extensive spread of carbapenem resistance, and their prevalence is increasing in many parts of the world.AimTo evaluate clinical and molecular epidemiology and mortality associated with CPO among patients.MethodsAll CPO from clinical and long-term healthcare surveillance cultures across Scotland in 2003–2017 were reviewed retrospectively. Polymerase chain reaction was used to detect genes coding for carbapenemases. A generalized linear mixed model was used to identify risk factors for mortality.FindingsIn total, 290 individuals with CPO were identified. The overall incidence increased over time (P<0.001) from 0.02 to 1.38 per 100,000 population between 2003 and 2017. A total of 243 distinct CPO isolates were obtained from 269 isolations in 214 individuals with available metadata. The majority of the isolates were Enterobacterales (206/243, 84.8%), and Klebsiella pneumoniae (65/206, 31.6%) and Enterobacter cloacae (52/206, 25.2%) were the most common species. VIM (75/243, 30.9%) and NDM (56/243, 23.0%) were the most common carbapenemases. The crude 30-day mortality rate was 11.8% (25/211), while the case fatality rate was 5.7% (12/211). Age >60 years [adjusted odds ratio (aOR) 3.36, 95% confidence interval (CI) 1.06–10.63; P=0.033], presence of non-fermenters (aOR 4.88, 95% CI 1.64–14.47; P=0.005), and systemic infection or organ failure (aOR 4.21, 95% CI 1.38–12.81; P=0.032) were independently associated with 30-day mortality.ConclusionThe incidence of CPO in Scotland is low but increasing. Awareness is required that inpatients aged >60 years, patients with systemic infection or organ failure, and patients presenting with non-fermenters are at higher risk of death from CPO.

Risk factors for transmission of carbapenem-resistant Enterobacterales to healthcare personnel gloves and gowns in the USA

Hospitals are sources for acquisition of carbapenem-resistant Entero-bacterales (CRE), and it is believed that the contamination of healthcare personnel (HCP) hands and clothing play a major role in patient-to-patient transmission of antibiotic-resistant bacteria. The aim of this study was to determine which HCP types, HCP-patient interactions, and patient characteristics are associated with greater transmission of CRE to HCP gloves and gowns in the hospital. This was a prospective observational cohort study that enrolled patients with recent surveillance or clinical cultures positive for CRE at five hospitals in four states in the USA. HCP gloves and gown were cultured after patient care. Samples were also obtained from patients' stool, perianal area, and skin of the chest and arm to assess bacterial burden. Among 313 CRE-colonized patients and 3070 glove and gown cultures obtained after patient care, HCP gloves and gowns were found to be contaminated with CRE 7.9% and 4.3% of the time, respectively. Contamination of either gloves or gowns occurred in 10.0% of interactions. Contamination was highest (15.3%) among respiratory therapists (odds ratio: 3.79; 95% confidence interval: 1.61-8.94) and when any HCP touched the patient (1.52; 1.10-2.12). Associations were also found between CRE transmission to HCP gloves or gown and: being in the intensive care unit, having a positive clinical culture, and increasing bacterial burden on the patient. CRE transmission to HCP gloves and gown occurred frequently. These findings may inform evidence-based policies about what situations and for which patients contact precautions are most important.

Genomic Epidemiology of MRSA During Incarceration at a Large Inner-City Jail.

Congregate settings, such as jails, may be a location where colonized detainees transmit methicillin-resistant Staphylococcus aureus (MRSA). We examined MRSA acquisition during incarceration and characterized the genomic epidemiology of MRSA entering the jail and isolated during incarceration. Males incarcerated at the Cook County Jail were enrolled within 72 h of intake and MRSA surveillance cultures collected. Detainees in jail at Day 30 were re-cultured to determine MRSA acquisition. A survey was administered to identify acquisition predictors. Genomic sequencing of surveillance and clinical isolates was integrated with epidemiologic and jail location data to track MRSA transmission pathways. 800 males were enrolled; 19% MRSA colonized at intake. Of 184 who reached Day 30 visit, 12 acquired MRSA. Heroin use before entering (OR 3.67, P = .05) and sharing personal items during incarceration (OR = 4.92, P = .01) were predictors of acquisition. Sequenced clinical USA300 isolates (n = 112) were more genetically similar than diverse intake USA300 strains (P < .001), suggesting jail transmission. Four acquired colonization isolates were within 20 single-nucleotide variant (SNVs) of other isolates; 4 were within 20 SNVs of an intake isolate, 2 for an acquisition isolate, and 1 for a clinical isolate. Individuals with genetically similar isolates were more likely to have had overlapping stays in the same buildings. There was a high MRSA burden entering jail. Genomic analysis of acquisition and clinical isolates suggests potential spread of incoming strains and networks of spread during incarceration, with spread often occurring among detainees housed in similar locations. Sharing personal items during incarceration is associated with MRSA acquisition and could be a focus for intervention.

Monthly endoscopy surveillance culture facilitates detection of breaches in the scope reprocessing procedure: 5‐year experience in an endoscopy center

AbstractThe aim of this study is to review the clinical impact of monthly microbiology surveillance culture for monitoring endoscope contamination after high‐level disinfection. Monthly surveillance culture of the endoscopes was conducted from January 2014 to December 2018 at our endoscopy center. A total of 1931 cultures were collected, including 765 cultures from 16 gastroscopes, 730 cultures from 18 colonoscopes, 379 cultures from 8 duodenalscopes, 46 cultures from 1 echoscopes, and 11 cultures from 1 enterscope. Cultures were obtained from ready‐to‐use endoscopes after a full reprocessing cycle and storage. Samples were cultured to test for aerobic and anaerobic bacteria. The positive culture rates for the endoscope were 2% (15/765) for gastroscopes, 1.9% (14/730) for colonoscopes, 0.8% (3/379) for duodenscopes, 4.3% (2/46) for echoscopes, and 9.1% (1/11) for enterscopes. These findings were predominantly attributed to human factors (71.4%, 25/35) followed by storage cabinet failure (14.3%, 5/35), automatic endoscope reprocessing failure (11.4%, 4/35), and endoscope channel damage (2.8%, 1/35). Multivariate analysis showed that the years 2015 (odds ratio [OR] 0.19, 0.04 to 0.91), 2016 (OR 0.21, 0.05 to 0.80), and 2017 (OR 0.22, 0.06 to 0.83) were associated with decreased risk of endoscope contamination. The age, type, and number of times the scope was used were not related to contamination. A low risk of endoscope contamination was found over a 5‐year period in our endoscopy center. The most common cause of contamination was human factor. Duodenalscopes showed the lowest scope contamination rate. We suggested the implantation of a systematic endoscope culture regardless of the type of scope to facilitate early detection of breaches in the scope reprocessing procedure in clinical practice.

Effectiveness of surveillance cultures for high priority multidrug-resistant bacteria in hematopoietic stem cell transplant units.

ABSTRACTSurveillance strategies to detect colonization are an important tool to prevent and control the spread of microorganisms in hematopoietic stem cell transplant (HSCT) units. The aim of this study was to evaluate routine surveillance cultures for screening colonization and infection by carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Pseudomonas aeruginosa (CRPa), and vancomycin-resistant enterococci (VRE). Surveillance cultures were collected (1,323 samples) from 200 patients admitted to an HSCT unit over one year; swabs were taken on admission and then weekly. We compared the positivity of cultures for each site, agent, clinical and epidemiological data according to the colonization status. Infection due to multidrug-resistant organisms (MDROs) occurred in 52 (21.5%) patients, 45 (86.5%) due to blood stream infection; 12 (23%) patients had a positive surveillance culture before the infection. Cultures of 554 (41.8%) samples were performed for CRPa, 413 (31.2%) for VRE and 356 (27%) for CRE. Of these, 179 (13.5%) were positive. Colonization by any MDRO, CRE or CRPa was associated with increased risk of infection (P < 0.05), but not with death. Previous colonization by an MDRO was a significant risk for infection by these pathogens, specially by CRE. Overall, rectal swabs had the highest positivity rate compared with other sites, oropharynx swabs were an option for CRPa, and fecal cultures showed low positivity. Although the impact of the strategy on the mortality of patients undergoing HSCT is not clear, routine VRE surveillance should be questioned with regard to patients undergoing auto-HSCT due to the additional cost and little impact on survival rates.

Controlling an Outbreak of Multidrug-resistant Acinetobacter baumannii in a Pediatric Intensive Care Unit: a Retrospective Analysis.

BackgroundMultidrug-resistant Acinetobacter baumannii (MDRAB) is widespread among intensive care units worldwide, posing a threat to patients and the health system. We describe the successful management of a MDRAB outbreak by implementing an infection-control strategy in a pediatric intensive care unit (PICU).MethodsThis retrospective study investigated the patients admitted to the PICU in periods 1 (8 months) and 2 (7 months), from the index MDRAB case to intervention implementation, and from intervention implementation to cessation of MDRAB spread. An infection-control strategy was designed following six concepts: 1) cohort isolation of colonized patients, 2) enforcement of hand hygiene, 3) universal contact precautions, 4) environmental management, 5) periodic surveillance culture study, and 6) monitoring and feedback.ResultsOf the 427 patients, 29 were confirmed to have MDRAB colonization, of which 18 had MDRAB infections. Overall incidence per 1,000 patient days decreased from 7.8 (period 1) to 5.8 (period 2). The MDRAB outbreak was declared terminated after the 6-month follow-up following period 2. MDRAB was detected on the computer keyboard and in condensed water inside the ventilator circuits. The rate of hand hygiene performance was the lowest in the three months before and after index case admission and increased from 84% (period 1) to 95% (period 2). Patients with higher severity, indicated by a higher Pediatric Risk of Mortality III score, were more likely to develop colonization (P = 0.030), because they had invasive devices and required more contact with healthcare workers. MDRAB colonization contributed to an increase in the duration of mechanical ventilation and PICU stay (P < 0.001), but did not affect mortality (P = 0.273).ConclusionThe MDRAB outbreak was successfully terminated by the implementation of a comprehensive infection-control strategy focused on the promotion of hand hygiene, universal contact precautions, and environmental management through multidisciplinary teamwork.

The Emergence of Surveillance Culture: The Relationships between Facebook Privacy Management, Online Government Surveillance, and Online Political Expression

ABSTRACT This study addresses how Facebook privacy-management openness (how comfortable Facebook users are sharing personal information) and perceived Facebook networks are interactively related to acceptance of online government surveillance and subsequent online political expression. Drawing on a nationally representative sample of Taiwanese, results indicate that while Facebook privacy-management openness is directly and positively associated with online political expression, Facebook privacy-management openness is negatively associated with online political expression indirectly through acceptance of online government surveillance. Moreover, the negative indirect relationship becomes stronger as users perceive their Facebook networks to be denser or highly connected.

577. Incidence and Outcomes of Positive Outpatient Surveillance Blood Cultures in Hematopoietic Stem Cell Transplant (HSCT) Patients with Graft Versus Host Disease (GvHD) On High Dose ≥ 0.5 mg/kg/day (HD) and Low Dose &amp;lt; 0.5mg/kg/day (LD) Steroid Therapy

BackgroundTreatment of GvHD with steroids increases the risk of infection in HSCT patients due to additive immunosuppression and may delay the diagnosis of infection due to lack of symptoms. Outpatient surveillance blood cultures in HSCT with GvHD being treated with HD steroids has demonstrated a blood culture positivity rate of 3.5%. Currently, the utility of surveillance cultures in patients receiving LD steroid therapy is unknown. Our practice includes weekly outpatient surveillance cultures for all GvHD patients treated with steroids regardless of the dose. The primary endpoint of this study was to assess the incidence of positive surveillance blood cultures in GvHD patients receiving HD or LD steroids. Secondary endpoints included number of patients treated, hospitalization, 30 day mortality due to infection, and organisms isolated.MethodsThis was a single-center, retrospective review of GvHD patients at Yale New Haven Hospital between January 2013 and May 2019. Patients were excluded if: lack of signs or symptoms of GvHD, treatment with steroids for any indication other than GvHD, and active GvHD without central line. Cultures from patients receiving antibiotics for concurrent infection were also excluded.ResultsA total of 71 patients met criteria with 901 blood cultures. On HD, eight patients (14%) had 12 positive cultures (4%), and on LD, 16 patients (25%) had 22 positive cultures (4%) (p=0.15). Treatment occurred in six patients (75%) with four (24%) requiring hospitalization on HD, and 12 patients (75%) with 10 (83%) requiring hospitalization on LD (p=0.45). The median duration of steroid therapy was 93 and 236 days with a median dose of steroids of 1mg/kg/day and 0.15mg/kg/day, respectively. The number of positive cultures/1000 steroid days was 1.2 on HD and 0.5 on LD (RR 2.2). 30 day mortality was only noted in one patient (8%) on LD. The most common organism in both groups was Coagulase-negative staphylococci with all six cultures on HD classified as contaminants and 6/10 cultures requiring treatment on LD.ConclusionAlthough the relative risk of positive surveillance blood cultures in HD patients compared to LD was twofold higher, there were clinically significant infections identified in the LD group.Disclosures All Authors: No reported disclosures

205. Rectal Stool Surveillance Cultures to Guide Empiric Antibiotic Therapy in Patients with Hematologic Malignancies with or without Hematopoietic Stem Cell Transplantation

BackgroundPatients with hematologic malignancies (HM) or hematopoietic stem cell transplant (HSCT) commonly receive broad-spectrum antimicrobials, often leading to the development of multidrug resistant organisms (MDRO). At our institution, rectal stool surveillance cultures (SSC) are done weekly on admitted adult patients with HMs or HSCT. The objective of this study is to determine the role of SSCs in predicting the development of a sterile site infection (StSI) with the same MDRO as identified in the SSC.MethodsWe retrospectively evaluated StSIs (blood, CSF, sputum/respiratory, pleural fluid, and urine) and SSC data from 242 adult patients admitted to the adult oncology ward at a large academic tertiary care center from 6/1/2017 to 2/28/2019. Demographics, SSC data, and StSIs in a 3-month period following the last SSC for each patient were collected from electronic medical records. SSCs were cultured on HardyCHROM ESBL™ media. MDRO similarity between SSC and StSI was determined by comparing susceptibility profiles. JMPÒ Pro 14.3.0 and RStudio were used for statistical analyses.ResultsTwo hundred forty-two patients yielded 732 SSCs. We eliminated SSCs with incomplete (< 3 months of follow up) data. Thus, 579 SSCs were included in the analyses. 64% of patients were male. Leukemias (55.4%), lymphomas (21.9%), and multiple myeloma (10.3%) were the most common HMs. HSCT recipients comprised 50.4%. SSCs were positive for a MDRO in 251 cases (vancomycin-resistant enterococci, 52.2%; extended-spectrum beta-lactamase (ESBL) producing organisms, 22.2%; and carbapenamase producing organisms, 4.4%). There were 54 StSIs documented where the MDRO was the same as the SSC MDRO. The NPV of the SSC was 95.1% (95%CI 0.93,0.97). The positive likelihood ratio of the SSC was 2.5 (95%CI 2.07,3.02).ConclusionOur results suggest that a negative SSC is associated with a lower probability of identifying a StSI with an MDRO. Clinically, this can be useful in providing the opportunity to judiciously guide antimicrobial therapy, thereby avoiding the unnecessary usage of broad-spectrum antimicrobials when no MDRO is identified in the SSC.Disclosures All Authors: No reported disclosures

248. Why so Much Vancomycin and Piperacillin/Tazobactam Usage Given Known Risks of Nephrotoxicity

BackgroundDespite years of published data describing the increased risk of nephrotoxicity with use of vancomycin and piperacillin/tazobactam (VPT), this combination remains one of the most utilized antibiotic combinations at our institution. There is limited data describing the appropriateness of empiric use of this broad-spectrum regimen. Our primary objective was to evaluate the appropriateness of the anti-methicillin resistant Staphylococcus aureus (MRSA), anti-pseudomonal, and anti-anaerobic spectrum of activity for patients empirically treated with this combination. Our secondary objective was to evaluate the appropriateness of diagnostic evaluation in patients started on this combination.MethodsA retrospective cohort study was performed on a random sample of unique patients prescribed the combination of VPT from October 2019 through March 2020. Demographic and clinical data were abstracted from the electronic medical record. Based on predetermined criteria, we evaluated the appropriateness of the spectrum of activity of empiric therapy and the diagnostic evaluation.ResultsOf 100 patients evaluated, 96 patients (96%) received VPT as empiric treatment. The indications for use are shown in Table 1. Pneumonia and soft tissue/bone/joint infections were the most common indications. The appropriateness of anti-MRSA, anti-pseudomonal, and anti-anaerobic therapy is shown in Table 2. In only 35% of patients was the full spectrum of activity appropriate. Of 47 patients treated empirically for pneumonia, 35 (74%) had an order for a respiratory culture and 7 (15%) for a nasal MRSA surveillance culture. Of 30 patients treated empirically for soft tissue//joint infections, wound cultures were obtained in 22 (73%). Nineteen patients underwent surgical intervention, of whom 17 (89%) had cultures obtained.Table 1. Indications for Empiric Vancomycin and Piperacillin/tazobactam Combination Therapy Table 2: Appropriateness of Spectrum of Activity for Empiric Vancomycin and Piperacillin/tazobactam Combination Therapy ConclusionAt our institution VPT use was usually empiric and unnecessarily broad for the syndrome being treated. Microbiologic testing was suboptimal and may have resulted in prolonged therapy. Although interventions aimed at de-escalating VPT are useful, interventions aimed at ensuring appropriate empiric use of this combination and ensuring appropriate diagnostic testing may be just as important.Disclosures All Authors: No reported disclosures

869. Outbreak of Vancomycin Resistant Enterococcus faecium (VREfm) in a Hematology Unit Identified Through Whole Genome Sequencing

BackgroundVREfm is a major cause of Hospital Acquired Infection in the United States. We analyzed all the VREfm infections that occurred in our institution between 2018 and 2019 using Whole Genome Sequencing (WGS) to understand epidemiological relationship between previously unidentified clusters. In this study we describe a cluster in our hematology oncology unit.MethodsA total of 109 discrete VREfm isolates from 66 patients were analyzed. VREfm isolates used in this study were identified from positive blood and urine cultures. Genomic deoxyribonucleic acid (DNA) was extracted from pure cultures. The purity and integrity of extracted DNA were determined using appropriate assays. Library construction and sequencing were conducted and Multi Locust Sequence Typing (MLST) obtained (image 1). Phylogenomic tree was plotted using the Interactive Tree of Life (image 2).Image 1 - methods Image 2 - Tree of Life ResultsTotal of 7 clusters were identified. Here we describe one cluster (image 3) with the highest genetic similarity which showed maximum difference of 5 Single Nucleotide Polymorphisms (zero between patient 1 and 2, image 4). The cluster is composed of 24 clinical strains of VREfm from 6 patients, over a 9 month time period (Image 5). All patients had hematologic malignancies; 4/6 patients had received recent chemotherapy and 5/6 patients were neutropenic. 4 patients were admitted in a single unit (labelled E7), 1 patient was on a sister unit (labelled F7); and 1 patient was in the cancer infusion center. All patients had central venous access placed by radiology at the time of diagnosis of infection and had visited our outpatient infusion center multiple times during this time frame.Image 3 - Close look at cluster 1 Image 4 - Dendrogram of 106 isolates performed with coreSNP(Single Nucleotide Polymorphisms) pairwise distances. • Dendogram shows different patients (same color for isolates that belong to the same patient) and the patient numbers. • Besides the patient number, the number of largest number SNPS that separate those isolates is shown. • Branches represent the number of coreSNPs that differ strains from that branch. As you see isolates from cluster 1 differ in a maximum of 5 SNPs but isolates of patient 1 and patient 2 differ in 0 SNPs between them. Cluster 1 is represented by a green square. Image 5 - Time period of infections ConclusionThe prolonged period in our cluster argues in favor of an environmental niche in the hospital unit. We are unable to elucidate pattern of transmission in a cluster of infections without knowing patient colonization of VREfm; because we are likely looking at the tip of the iceberg when analyzing infected cases. It is difficult to ascribe causality to any one of these exposures without concomitant surveillance cultures of environment and personnel. Retrospective WGS is of limited value in infection control. We now have third generation sequencing with the MinION device to do real time sequencing with which we also validated some of our samples.DisclosuresAtul Kothari, MD, Ansun Biopharma (Consultant)

Antibiotic Exposure Is Not Associated With Clearance of Bronchoalveolar Growth: Results From a Prospective Ventilator-Associated Pneumonia Study

Ventilator-associated pneumonia is poorly understood in trauma. Ventilated trauma patients can develop bacterial burden without symptoms; the factors that influence this are unknown. Injured adults ventilated for > 2days were enrolled. Mini-bronchoalveolar lavage was performed for 14days or until extubation. Semi-quantitative cultures were blinded from clinicians. All cultures with > 104 colony forming units (CFU) were assessed for antibiotic exposure (ABXE) and spectrum of coverage. mBAL CFU was assessed daily. 60 patients were ventilated for 9days (median). There were 75 with > 104 CFU. 46 had > 104 CFU and no ABXE on the sample day. 74% had clearance or a decrease (CoD) in CFU without ABXE. 29 had > 104 CFU and ABXE on the sample day. 19 had ABXE with pathogen coverage. 84% had CoD in CFU. 10 had ABXE with no spectrum of coverage. 1/10 had increased CFU and the remaining 9/10 CoD in CFU. The three groups were not statistically different on chi-squared analysis. Clearance of pathogens on surveillance cultures was unaffected by ABXE.