Characterization of extended spectrum beta-lactamase-producing Klebsiella pneumoniae from Beijing, China

Fourteen clinical isolates of Klebsiella pneumoniae with extended-spectrum beta -lactamases (ESBLs) were detected by the double disk synergy test and the Etest ESBL strip. Co-resistances included high MICs for aminoglycosides , fluoroquinolones, tetracyclines, and trimethoprim/sulphamethoxazole. Co-r esistance was not observed in five of the 14 strains. These isolates were a ll genetically distinct as determined by the automated ribotyping method. I soelectric focusing documented the presence of multiple beta -lactamases (o ne to four per isolate) with pIs ranging from 5.4 to 8.4. The majority of i solates contained beta -lactamases with pI values of 7.6 and 8.4 consistent with SHV-type ESBLs and an Amp C enzyme, respectively. Emerging ESBL strai ns in K. pneumoniae compromise the use of agents such as cefotaxime, ceftri axone, ceftazidime in China; leading to the expansion of quality infection control practices and formulary management programmes to minimize clonal ex pansion. (C) 2001 Elsevier Science B.V. and International Society of Chemot herapy. All rights reserved.