Prevalence of Carbapenem-Resistant Klebsiella pneumoniae Infection in Southern China: Clinical Characteristics, Antimicrobial Resistance, Virulence, and Geographic Distribution

Carbapenem-resistant Klebsiella pneumoniae (CRKP) strains pose a significant threat to public health. In this study, a survey was conducted in the Jiangxi Province of China, covering a total of 140 CRKP strains collected from 11 hospital laboratories from June 2016 to January 2018. All CRKP isolates were subjected to antimicrobial susceptibility testing, capsular serotypes, virulence gene profiles, multilocus sequence typing, and pulsed-field gel electrophoresis. The differences in the patient characteristics and distributions among the various regions were statistically significant (p <= 0.001). Most patients were hospitalized in intensive care units (30.0%) and burn departments (13.6%), with lower respiratory (52.1%) and urinary tract (15.7%) infections being most prevalent. A higher ratio of CRKP isolates were identified in the southern and central regions of Jiangxi than in the other regions. Only two carbapenemase genes, bla(KPC) and bla(NDM), were responsible for phenotypic resistance in the tested CRKP strains (46.5% and 22.1%, respectively), among which several major sequence types (STs), such as ST11 (27.8%) and ST23 (14.8%), were identified. A total of 39 virulent strains were detected, of which 22 strains were classified by capsule serotyping. Hypervirulent genes were most common in the eastern and central regions of Jiangxi. In conclusion, CRKP strains in the Jiangxi Province have varied geographic distributions; the resistance rates of isolates harboring bla(KPC) decreased from southern to northern regions, whereas the drug resistance gene bla(NDM) showed a tendency to spread from a central point to the surrounding areas. ST23 carbapenem-resistant hypervirulent K. pneumoniae is emerging, resulting in an urgent need to enhance clinical awareness.