The washing machine as a reservoir for transmission of extended spectrum beta-lactamase (CTX-M-15)-producing Klebsiella oxytoca ST201 in newborns.

During the time period from April 2012 to May 2013, 13 newborns (1 - 4 weeks old) and one child in a paediatric hospital ward in Germany were colonized with an extended spectrum betalactamase (ESBL) producing Klebsiella oxytoca (CTX-M-15). A microbiological source-tracking analysis, including human and environmental samples, was carried out to identify the source and transmission pathways of the K. oxytoca clone. In addition, different hygienic intervention methods were evaluated. Isolates of the K. oxytoca strains were detected in the detergent drawer and on the rubber door seal of a domestic washer-extractor machine, used in the same ward to wash laundry of the newborns as well as in two sinks. These strains were typed using PFGE and multi-locus sequence typing (MLST). The environmental findings were compared with those of the human strains and the isolates detected on the clothing. The results showed that the strains were identical using both techniques, (ST201 and pulse-field-gel-electrophoresis [PFGE] type-00531, a clone specific to this hospital and not previously isolated in Germany), emphasizing the washing machine as a reservoir and fomite for the transmission of these multidrug-resistant bacteria (MDR). After the washing machine had been taken out of use, no further colonizations were detected over a following 4-year period. [ABSTRACT FROM AUTHOR]