AUTHOR=Zhang Jing , Zhou Kai , Zheng Beiwen , Zhao Lina , Shen Ping , Ji Jinru , Wei Zeqing , Li Lanjuan , Zhou Jianying , Xiao Yonghong 

TITLE=High Prevalence of ESBL-Producing Klebsiella pneumoniae Causing Community-Onset Infections in China

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01830

DOI=10.3389/fmicb.2016.01830

ISSN=1664-302X

ABSTRACT=<p>The aim of this work was to investigate the epidemiological and genetic characteristics of ESBL-producing <italic>Klebsiella pneumoniae</italic> (ESBL-Kp) causing community-onset infections. <italic>K. pneumoniae</italic> isolates were collected from 31 Chinese secondary hospitals between August 2010 and 2011. Genes encoding ESBL and AmpC beta-lactamases were detected by PCR. The isolates were assigned to sequence types (STs) using multi-locus sequence typing (MLST). Eleven ESBL-Kp strains were selected for whole-genome sequencing (WGS) for investigating the genetic environment and plasmids encoding ESBL genes. A total of 578 <italic>K. pneumoniae</italic> isolates were collected, and 184 (31.8%) carried ESBL genes. The prevalence of ESBL-Kp varied from different geographical areas of China (10.2–50.3%). The three most prevalent ESBL genes were <italic>bla</italic><sub>CTX-M-14</sub> (<italic>n</italic> = 74), <italic>bla</italic><sub>CTX-M-15</sub> (<italic>n</italic> = 60), and <italic>bla</italic><sub>CTX-M-3</sub> (<italic>n</italic> = 40). MLST assigned 127 CTX-M-14 and CTX-M-15 producers to 54 STs, and CC17 was the most prevalent population (12.6%). STs (23, 37, and 86) that were known frequently associated with hypervirulent <italic>K. pneumoniae</italic> (hvKP) account for 14.1% (18/127). Phylogenetic analysis by concatenating the seven loci of MLST revealed the existence of ESBL-producing <italic>K. quasipneumoniae</italic> (two strains) and <italic>K. varricola</italic> (one strain), which was further confirmed by WGS. This study highlights the challenge of community-onset infections caused by ESBL-Kp in China. The prevalence of STs frequently associating with hvKP should be of concern. Surveillance of ESBL-KP causing community-onset infections now appears imperative.</p>