Dissemination of CTX-M type β-lactamases in Enterobacteriaceae isolates in the people's Republic of China

Previously there have been a number of reports of extended spectrum P-lactamase (ESBL) producing isolates of the family Enterobacteriaceae in Asia. We first reported the occurrence of bla(CTX-M) in Guangzhou, China, subsequently there have been reports of blaCTX-M from a number of other south Asian countries. Initial surveillance study data suggested that blaCTX-M might be widely distributed in China. This study examines the type of bla(CTX-M) Occurring in other major population centres in China. Initial disk diffusion method susceptibility testing (NCCLS) selected ESBL producing Escherichia coli and Klebsiella pneunioniae isolates from Beijing and near Wuhan, PRC. After screening in both China and the UK, 13 isolates producing CTX-M ESBLs were identified and studied, 11 also produced TEM-1, and 4 also produced SHV-1. Sequence analysis of the bla(CTX-M) containing isolates revealed these isolates contained two different bla(CTX-M), three with bla(CTX-M-3) and 10 with bla(CTX-M-14). After comparison with other previously published studies in the English language, we conclude that the most prevalent bla(CTX-M) so far reported in Asia are bla(CTX-M-14) and bla(CTX-M-3). (C) 2003 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.