Detection of the genotypes coding plasmid-mediated AmpC in the isolates of Escherichia coli

Objective To investigate the genotypes coding plasmid-mediated AmpC in the isolates of Escherichia coli. Methods 42 strains of Cefoxitin and third-generation cephalosporin -resistant Escherichia coli were isolated from clinical specimens in our hosptial. AmpC and extened spectrum β-lactamases (ESBLs) were determined by modified three-dimensional test. Multiplex polymerase chain reaction was used to detect the genotypes of AmpC. The products of PCR were sequenced. Results Of 42 isolates,18 isolates only produced ESBLs and 4 isolates only produced AmpC. 1 isolates produced either ESBLs or AmpC. Among 5 isolates producing AmpC, The products of mPCR of 4 isolates were positive. The genotypes coding plasmid-mediated AmpC in 4 isolates all were DHA-1. Conclusion The rate of ESBLs in the isolates of Escherichia coli is very high. The genetype coding plasmid-mediated AmpC in the isolates of Escherichia coli is DHA-1.