Multilocus sequence types and virulence determinants of hypermucoviscosity-positive klebsiella pneumoniae isolated from community-acquired infection cases in harbin, north China

Abstract

We investigated the molecular epidemiologic characteristics and virulence of hypermucoviscosity-positive Klebsiella pneumoniae in mainland China. We detected 16 hypermucoviscosity-positive strains in 65 total clinical isolates (24.62z). We found that 68.75z (11/16) of the positive strains had K2 genotype and carried the rmpA and iucA genes. Multilocus sequence typing revealed 5 sequence types (STs): ST65 [7], ST23 [4], ST86 [3], ST412 [1], ST375 [1], whereas the remaining 4 isolates were defined as other STs. The order of the median lethal dose values for the ST types was ST23 (2.19 × 103 CFU/mouse) ＜ ST86 (1.70 × 104 CFU/mouse) ＜ ST65 (5.05 × 107 CFU/mouse) ＜ the other STs (1.90 × 108 CFU/mouse). In conclusion, the K2 with ST65 carrying rmpA and iucA was the most predominant among the hypermucoviscosity-positive K. pneumoniae strains obtained from community-acquired infection cases in Harbin, North China. Sequence types are a valuable tool to predict the risk of K. pneumoniae infection.