Nosocomial spread of OXA-232-producing Klebsiella pneumoniae ST15 in a teaching hospital, Shanghai, China

Background: The spread and outbreak of Enterobacteriaceae producing OXA-48-like carbapenemases have become more and more prevalent in China. Results: A total of 62 non-duplicated OXA-232-producing K. pneumoniae (OXA232Kp) were isolated between 2015 and 2017. An outbreak of OXA232Kp was observed in burn ICU. The 62 OXA232Kp isolates were all belongs to ST15 and categorized into two PFGE types (A and B). Type A was dominated of the isolates, which contained 61 clinical isolates and divided into 10 subtypes (A1-A10). In addition, most of OXA232Kp strains exhibited low-level carbapenems resistance. All strains carried a 6141 bp ColKP3 plasmid harboring the bla(OXA-232) gene which is highly homologous to other bla(OXA-232)-bearing plasmids involved in other studies in eastern China. Conclusions: In this study, clone transmission of OXA232Kp ST15 was observed. Highly significant homology among the bla(OXA-232)-bearing plasmids indicated the important role of the 6.1 kb ColE-like plasmid on the prevalence of bla(OXA-232) gene in China.