Stenotrophomonas maltophilia outbreak with a commercial blood gas injector as the culprit and interventions for source and prevention: A possible passage between patient and ECMO water heater device

Abstract

Despite low virulence of Stenotrophomonas maltophilia, it represents one of the leading drug-resistant bacteria. We report a large outbreak of S. maltophilia infection associated with an unexpected source, which turned out to be a commercial needleless blood gas injector. Over a period from January 1 to December10, 2021, 113 patients were identified to have S. maltophilia infection as documented by positive cultures from the clinical samples, extracorporeal membrane oxygenation (ECMO) water heater devices and commercial needleless blood gas injectors. Sixty-seven isolates (59 clinical, 4 ECMO, 4 blood gas injectors) were sent for molecular analysis. Both arbitrarily primed polymerase chain reaction and pulsed-field gel electrophoresis analyses showed 12 distinct genotypes. Of 67 isolates, 58 were clonally related (86.6%), with 52 indistinguishable strains from 4 blood gas needleless injectors, 46 patients' samples (78%), and 2 ECMO samples (50%). Two ECMO samples and 1 clinical sample were clonally identical. In the event that eradication of infections would not be possible despite taking all environmental disinfection measures including the ECMO devices, unexpected sources, such as a commercial needleless blood gas injector, should not be omitted from the list for surveillance. In addition, obtaining surveillance cultures of ECMO water reservoirs should be placed in the routine clinical practice.