Concurrent transmission of multiple carbapenemases in a long-term acute-care hospital.

Abstract

We investigated concurrent outbreaks of Pseudomonas aeruginosa carrying blaVIM (VIM-CRPA) and Enterobacterales carrying blaKPC (KPC-CRE) at a long-term acute-care hospital (LTACH A). We defined an incident case as the first detection of blaKPC or blaVIM from a patient's clinical cultures or colonization screening test. We reviewed medical records and performed infection control assessments, colonization screening, environmental sampling, and molecular characterization of carbapenemase-producing organisms from clinical and environmental sources by pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. From July 2017 to December 2018, 76 incident cases were identified from 69 case patients: 51 had blaKPC, 11 had blaVIM, and 7 had blaVIM and blaKPC. Also, blaKPC were identified from 7 Enterobacterales, and all blaVIM were P. aeruginosa. We observed gaps in hand hygiene, and we recovered KPC-CRE and VIM-CRPA from drains and toilets. We identified 4 KPC alleles and 2 VIM alleles; 2 KPC alleles were located on plasmids that were identified across multiple Enterobacterales and in both clinical and environmental isolates. Our response to a single patient colonized with VIM-CRPA and KPC-CRE identified concurrent CPO outbreaks at LTACH A. Epidemiologic and genomic investigations indicated that the observed diversity was due to a combination of multiple introductions of VIM-CRPA and KPC-CRE and to the transfer of carbapenemase genes across different bacteria species and strains. Improved infection control, including interventions that minimized potential spread from wastewater premise plumbing, stopped transmission.