Heather Smith’s research while affiliated with The Ohio State University and other places

Background: Candida auris is an emerging threat to hospitalized patients and invasive disease is associated with high mortality. This study describes clinical and microbiological characteristics of nine patients identified with C. auris at Ohio State Wexner Medical Center discovered through active surveillance or clinical investigation and uses whole genome sequencing (WGS) to compare isolates. Methods: In November 2022, an active C. auris surveillance program was implemented to screen patients admitted to high-risk units (intensive care units and progressive care units). Bilateral axilla and groin swabs were obtained upon unit admission and, if positive, were submitted for C. auris polymerase chain reaction (PCR) with culture and sensitivity testing. Patients with a positive screening or clinical isolate from November 2022 to November 2023 underwent chart review for clinical characteristics, microbiologic data, and index admission information. For each isolate, DNA was extracted and WGS was performed. Core single nucleotide polymorphism (SNP) variation identified from the sequence data was used to infer genetic relationships among the isolates. Results: Nine patients were identified between November 2022 and November 2023. The clinical and microbiologic characteristics are summarized in Table 1. All patients were hospitalized at various acute care facilities across the state at least once in the preceding 12 months. C. auris was determined to be present on admission for 6 patients. For 5 of these patients, it was their first interaction with our healthcare system. Three patients were not in contact isolation for >3 days before C. auris was identified. Unit wide point-prevalence screening was completed in these cases and no evidence of transmission was found. WGS showed eight of the nine isolates were related with 28 or less core SNP differences between isolates (Figure 1). One isolate (8) was genetically distinct with >45000 core SNP differences. Five isolates were highly related with a range of 4-15 SNP differences. No temporal or spatial overlap at our institution was identified among these five patients. Conclusions: The active surveillance program identified several patients colonized with C. auris in addition to those found through clinical testing. Multiple risk factors for C. auris were identified with high patient mortality (67%). Majority of the isolates were closely related without association with a known outbreak or epidemiologic link, suggesting a possible diffuse common reservoir. Next steps with surveillance in acute care and long-term care facilities will be critical for early detection to halt transmission of this organism.

Background: Multidrug-resistant organisms (MDROs) are increasingly implicated in nosocomial outbreaks worldwide. We evaluated whole-genome sequencing (WGS) as an adjunctive epidemiological tool to identify infection clusters and MDRO transmission in the healthcare setting. Methods: Clinical isolates of carbapenem-resistant Enterobacterales (CRE) from July 1, 2021, to June 30, 2022, underwent Illumina WGS. Assembled genomes were taxonomically classified with GTDB-Tk software and were typed using multilocus sequence typing (MLST). Average nucleotide identity (ANI) was calculated between genomes. Numbers of differences among core single-nucleotide polymorphisms (SNPs) were calculated for pairs within taxonomic groups, and the data were evaluated in the context of patient dates and locations of care obtained from the electronic medical record. Results: In total, 39 CRE isolates underwent WGS (Fig. 1). Klebsiella pneumoniae represented the largest number of isolates (n = 18). Using MLST, 2 distinct groups of K. pneumoniae were identified (ST307 and ST258) with 5 and 4 isolates, respectively (Fig. 2). Within ST307, SNP differences ranged between 8 and 115. 3 isolates (CRE8, CRE10, and CRE12) were collected within 4 weeks of each other and had ≤26 pairwise SNP differences. Notably, CRE8 and CRE10 were located on the same unit at the same time and used the same MRI scanner on the same day. CRE35 had >95 SNP differences and was admitted 8 months prior to others in ST307 but had surgery in the same OR as CRE8. Within ST258, pairwise comparison of samples revealed 139–588 SNP differences. CRE21, CRE31, and CRE33 had SNP differences of ≤150. These patients were in the same hospital room (CRE33 and CRE21) and unit (CRE31 and CRE33), but they did not overlap temporally. CRE37 had >580 SNP differences, with no overlap in hospitalization dates or locations with other patients. Conclusions: Two closely related K. pneumoniae isolate populations were identified using WGS. Strong temporal and spatial commonalities were identified among isolates with few SNP differences. Isolate pairs with intermediate SNP differences shared spatial commonalities, suggesting possible indirect transmission between patients. No common exposures were identified for pairs with large numbers of SNP differences. WGS is an evolving tool to detect outbreak clonal populations of MDRO not identified through traditional epidemiologic techniques. WGS can provide insight into transmission patterns and the role of environmental contamination in propagating these nosocomial infections. More studies are needed to define the role and clinical significance of isolates with intermediate SNP differences in transmission of these pathogens between hosts and the healthcare environment. Disclosures: None

Background: Carbapenem-resistant Enterobacterales (CRE) are an increasing threat to patient safety but only a small percentage of CRE identified are NDMs. Since 2018, clinical CRE isolates have been submitted to the Ohio Department of Health for sequencing and NDM cases have notably increased since that time. Candida auris is an emerging pathogen with similar risk factors for colonization as CRE. Methods: A point-prevalence study was initiated after an index patient was identified with NDM CRE infection or colonization during their inpatient admission. Two patient populations were included in the study: current patients on the same unit as the index patient and currently hospitalized patients who overlapped on any unit with the index patient for at least 72 hours. Patients had perirectal screening for CRE (via PCR) and axilla or groin screening for C. auris (via Xpert Carba-R Assay). Patients were excluded if they had been discharged, expired, or refused testing. Results: We completed 5 point-prevalence studies from March 21, 2021, to October 15, 2021. The index patients were admitted at different times and across 2 campuses including medical, cardiac, and surgical ICUs as well as medical-surgical and inpatient rehabilitation units. Moreover, 3 species of NDM were identified from urine and 2 species were identified from bronchoalveolar lavage: Enterobacter hormaechei , Citrobacter freundii , and Enterobacter cloacae complex. C. freundii and E. cloacae complex both had dual mechanisms of NDM and KPC. Although some of the index patients overlapped temporally within the health system, none overlapped in the same unit or building. None of the patients had recently received health care outside the United States, although 1 patient had emigrated from Togo >5 years prior and 4 had had prior local healthcare exposure within 12 months of admission. Also, 147 patients were identified for screening; 105 consented, 32 declined, and 10 were excluded due to being discharged, deceased, or unable to consent. Inpatient point-prevalence screening tests for all patients tested (n = 105) were negative for NDM CRE and C. auris . Conclusions: Despite an increase of inpatients with NDM CRE, evidence of patient-to-patient transmission was not identified, likely resulting from adherence to standard precautions. The diversity of species and lack of international travel suggests that these patients likely acquired NDM CRE from a local reservoir in the community or healthcare settings. Given the continued increase in NDM CRE without traditional risk factors, it is critical for hospitals and public health agencies to collaborate to identify these organisms and that they develop surveillance programs to clarify risk factors for colonization. Funding: None Disclosures: None

Background: The Ohio State University Wexner Medical Center identified a cluster of coronavirus disease 2019 (COVID-19) cases on an inpatient geriatric stroke care unit involving both patients and staff. The period of suspected severe acute respiratory coronavirus virus 2 (SARS-CoV-2) transmission and exposure on the unit was December 20, 2020, to January 1, 2021, with some patients and staff developing symptoms and testing positive within the 14 days thereafter. Methods: An epidemiologic investigation was conducted via chart review, staff interviews, and contact tracing to identify potential patient and staff linkages. All staff who worked on the unit were offered testing regardless of the presence of symptoms as well as all patients admitted during the outbreak period. Results: In total, 6 patients likely acquired COVID-19 in the hospital (HCA). An additional 6 patients admitted to the unit during the outbreak period subsequently tested positive but had other possible exposures outside the hospital (Fig. 1). One patient failed to undergo COVID-19 testing on admission but tested positive early in the cluster and is suspected to have contributed to patient to employee transmission. Moreover, 32 employees who worked on the unit in some capacity during this period tested positive, many of whom became symptomatic during their shifts. In addition, 18 employees elected for asymptomatic testing with 3 testing positive; these were included in the total. Some staff also identified potential community exposures. Additionally, staff reported an employee who was working while symptomatic with inconsistent mask use (index employee) early in the outbreak period. The index employee likely contributed to employee transmission but had no direct patient contact. Our epidemiologic investigation ultimately identified 12 employees felt to be linked to transmission based on significant, direct patient care provided to the patients within the outbreak period (Fig. 1). In addition, 3 employees had an exposure outside the hospital indicating likely community transmission. Conclusions: Transmission was felt to be multidirectional and included employee-to-employee, employee-to-patient, and patient-to-employee transmission in the setting of widespread community transmission. Interventions to stop transmission included widespread staff testing, staff auditing regarding temperature and symptom monitoring, and re-education on infection prevention practices. Particular focus was placed on appropriate PPE use including masking and eye protection, hand hygiene, and cleaning and disinfection practices throughout the unit. SARS-CoV-2 admission testing and limited visitation remain important strategies to minimize transmission in the hospital. Funding: No Disclosures: None