Antimicrobial Susceptibility and Molecular Epidemiology of Multidrug-Resistant Klebsiella pneumoniae in Central China.

Extended-spectrum-beta-lactamase-producing and carbapenemase-producing Klebsiella pneumoniae strains have rapidly spread through clinical units worldwide. This study investigated the epidemiology and resistance profiles of K. pneumoniae strains isolated in central China between 2009 and 2014. Antimicrobial susceptibility testing and polymerase chain reaction were used to investigate the prevalence of extended-spectrum beta-lactamases (ESBL) and carbapenemase production by these K. pneumoniae strains, and the prevalence of K. pneumoniae carbapenemase (KPC)-producing K. pneumoniae was investigated by multilocus sequence typing. Carbapenem resistance has emerged as a major concern in K. pneumoniae infections, as phenotype testing has detected carbapenemases in nearly 20% of isolates. KPC-producing isolates in a local epidemic were clonally related, with ST11 being the reservoir for the blaKPC-2 gene and ESBL genes. During the 6-year collection period, the prevalence of ESBLs was dynamic, and suggested that blaCTX-M-55 might become prevalent in the future. Our findings demonstrate the high prevalence of carbapenemase- and ESBL-producing K. pneumoniae in central China and predict a future local epidemic of KPC-2 and CTX-M-55.