Prevalence and characteristics of surgical site hypervirulent Klebsiella pneumoniae isolates

BACKGROUND: We aim to determine the prevalence of hypervirulent Klebsiella pneumoniae (hvKp), which causes surgical site infections (SSIs), and describe the microbiological and molecular characteristics of hvKp isolates. METHODS: Non‐duplicate K. pneumoniae strains were isolated from wound drainage specimens of postoperative patients at the Chinese PLA General Hospital between September 2008 and July 2017. Antimicrobial susceptibility, string test, pulsed‐field gel electrophoresis (PFGE), and genome sequencing analyses were performed. RESULTS: Fifty‐one K. pneumoniae strains were isolated from wound drainage specimens collected from postoperative patients. Twenty‐six hvKp strains, including 17 (17/37, 46.0%) and 9 (9/14, 64.3%) hvKp strains, were isolated from 37 and 14 patients with SSIs and community‐acquired infections (CAIs), respectively. Notably, 4 extended‐spectrum beta‐lactamase (ESBL)‐producing hvKp strains (4/26, 15.4%) and 2 carbapenem‐resistant hvKp strains (2/26, 7.7%) were found. Thirteen K1 serotype (13/26, 50.0%) and 7 K2 serotype (7/26, 26.9%) strains were identified. Phylogenetic analysis results showed that 13 K1 serotype isolates exhibited a high degree of clonality, while 7 K2 serotype strains were genetically unrelated. MLST analysis indicated that there was a strong correlation between ST23 and the K1 serotype. ST65, ST86, and ST375 were prevalent in K2 serotype strains. Almost all hvKp strains (24/26, 92.3%) harbored large virulence plasmids with a high degree of homology to pNTUH‐K2044 and sizes ranging from 140 to 220 kbp. CONCLUSIONS: HvKp strains were prevalent in SSIs. Effective surveillance and control measures should be implemented to prevent the dissemination of such organisms, including the ESBL‐producing and carbapenem‐resistant hvKp strains.