2466. What’s Lurking in the Drain? Serial transmission of NDM-1Klebsiella pneumoniae to patients admitted 9 months apart to the same ICU room

BACKGROUND: We evaluated the role of an in-room sink in NDM-1 K. pneumoniae (NDMKP) transmission. METHODS: In October 2017, Infection Prevention (IP) initiated weekly point prevalence rectal screening cultures in 4 ICUs. In 3/2018, IP launched an epidemiologic and environmental investigation following identification of a patient with NDMKP rectal colonization. Environmental samples including swabs of biofilm from drains and water from p-traps were obtained from the in-room sink. Illumina whole-genome sequencing (WGS) was performed on all NDMKP patient and environmental isolates. Single nucleotide variants (SNVs) were identified against the reference Klebsiella pneumoniae strain MLST15 (NZ_CP022127), and isolates within 150 SNVs of each other were considered to be genomically related. RESULTS: Two patients were identified with NDMKP infection or colonization between July 2017 and March 2018. The index patient had prolonged hospitalization and developed NDMKP bacteremia on hospital day (HD) 30. Approximately 9 months later, the second patient was admitted to the same ICU room that had been occupied by the index patient for 13 days and was identified to have NDMKP rectal colonization on HD 5. Environmental samples from the in-room sink of the ICU room grew NDMKP. WGS demonstrated relatedness between NDMKP isolates from the 2 patients (112 SNV), the index patient and the sink (52 SNV), and the second patient and the sink (80 SNV). The in-room sink was replaced in 4/18 and no further cases of NDMKP infection or colonization have been identified at DUH in over 12 months. CONCLUSION: We report an NDM-1 K. pneumoniae transmission event possibly related to a contaminated in-room sink drain. Remarkably, 9 months elapsed between the index case and the second case, with no additional interim cases detected on weekly point-prevalence screening or clinical cultures. The long duration of time between and the index patient, secondary case, and sink culture may explain why WGS showed relatedness but not identical clones. Education around sink use, design, and more effective cleaning strategies are needed to mitigate environment-to-patient transmission of CRO. DISCLOSURES: All authors: No reported disclosures.