Genomic Analysis Of A KPC-2-Producing Klebsiella Pneumoniae ST11 Outbreak From A Teaching Hospital In Shandong Province, China

PURPOSE: Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae bacteria causes nosocomial infections worldwide. However, KPC-producing K. pneumoniae outbreak has never been reported in Shandong Province, China. The purpose of our study was to elucidate the epidemiological and drug resistance mechanisms of KPC-producing K. pneumoniae strains collected from a large teaching hospital in Shandong during the outbreak. Moreover, we attempted to characterize the genetic environment and phylogenetic analysis of bla(KPC-2) in outbreak isolates. METHODS: We monitored a 64-day outbreak of infection in a general hospital in Shandong Province, and the bacteria causing the infection were all ST11-type K. pneumoniae. The genotype correlation of KPC-producing K. pneumoniae isolates was assessed by whole-genome sequencing (WGS) phylogenetic analysis. Subsequent studies included antibiotic susceptibility testing, multilocus sequence typing (MLST) and S1-pulsed-field gel electrophoresis (S1-PFGE), Southern blot hybridization. RESULTS: From February 1, 2018 to April 5, 2018, 14 KPC-producing K. pneumoniae isolates from different wards were collected. All 14 isolates were resistant to carbapenems and carried the extended-spectrum β-lactamase (ESBL) gene as well as fosA, and sul genes. Whole-genome analysis showed that all 14 the outbreak isolates were all ST11 type. The bla(KPC-2) carrying plasmids were all belong to IncFII(K2) type, and the size ranged from 94 kb to 368 kb. CONCLUSION: As far as we know, this report first describes the genomics characterization of KPC-2-producing K. pneumoniae outbreak isolates from Shandong Province, China. In our study, these isolates appeared to be cloned, and ST11 K. pneumoniae was the major clone caused the outbreak. Therefore, routine surveillance of such strains in this region is urgently warranted.