Expanding of ST11 Carbapenemase-Producing Klebsiella pneumoniae Subclones in a Chinese Hospital, Shenzhen, China.

Background ST11 is the most prevalent sequence type of clinical Klebsiella pneumoniae in China. Methods We investigated the characteristics of the ST11 subclones using core genome multi-locus sequence typing (cgMLST). Ninety-three carbapenemase-producing K. pneumoniae isolates were collected at Shenzhen People's Hospital. Then, whole-genome sequencing and cgMLST were used to discriminate apparent subclones within the ST11 group. Results We analyzed the prevalence and genetic relationships of these subclones. ST11 and K. pneumoniae carbapenemase (KPC-2) were the predominant genotype and carbapenemase, respectively, in the clinical carbapenemase-producing K. pneumoniae strains. cgMLST scheme genotyping divided the ST11 group into two clades across seven complex types (CTs). CT1313 was the most prevalent subclone. The deletion of galF and a high frequency of SNPs in genes associated with the stress- and SOS-responses were found in CT1291 and CT2405 over time, respectively. Conclusion Our results indicated that the subclones of the ST11 group had different patterns of prevalence. Highly discriminatory genotyping techniques, such as cgMLST scheme, should be used in further molecular epidemiology investigations.