Journal of clinical microbiology
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J. Clin. Microbiol. · Apr 2008
Prevalence of plasmid-mediated AmpC beta-lactamases in a Chinese university hospital from 2003 to 2005: first report of CMY-2-Type AmpC beta-lactamase resistance in China.
The aim of this study was to investigate the prevalences of plasmid-mediated AmpC beta-lactamases (PABLs) in isolates of Escherichia coli and Klebsiella spp. from a university hospital in China. A total of 1,935 consecutive nonrepeat clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca were collected between January 2003 and July 2005. The isolates with cefoxitin zone diameters less than 18 mm (screen positive) were selected for PCR of the bla(AmpC) genes and sequencing. ⋯ The results of random amplified polymorphic DNA analysis indicate that the prevalences of DHA-1-producing K. pneumoniae and CMY-2-producing E. coli strains were not due to epidemic strains. In conclusion, DHA-1 was the most prevalent acquired AmpC beta-lactamase in this collection of isolates from a medical center in China, and DHA-1-producing K. pneumoniae was the most prevalent bacterium harboring a PABL. To the best of our knowledge, this is the first report of CMY-2-type AmpC beta-lactamases in the Chinese mainland.