Analysis and Detection of Plasmid-mediated AmpC β-lactamase Genes in Klebsiella pneumoniae of One Hospital in Changsha by Using Multiplex PCR

To investigate the prevalence and genotype of the plasmid-mediated AmpC β-lactamases of Klebsiella pneumoniae in clinical isolates from one hospital of Changsha,a total of 104 non-duplicate clinical isolates of Klebsiella pneumoniae,which were saved mindedly from March 2008 to October 2010 in this hospital,were selected by cefoxitin disk diffusion test firstly.Then multiple PCR method was employed to test ampC resistance genotypes in AmpC enzyme phenotype-positive Klebsiella pneumoniae strains.Among the 104 Klebsiella pneumoniae clinical isolates,19 strains were not sensitive to cefoxitin disk.12 strains of these 19 non-sensitive clinical isolates were presented positive at the 400 bp bands(11 strains) and 350 bp band(1 strain) separately by multiple PCR,and the specific PCR determined that these 12 strains carried DHA type(11 strains) and ACC type(1 strain) ampC resistance gene seperately.The separation rate of producing plasmid-mediated AmpC enzyme of Klebsiella pneumoniae was 11.5%(12/104).The separation rate of producing plasmid-mediated AmpC enzyme of clinical isolates of Klebsiella pneumoniae strains in this hospital is high,and much attention should be paid to their detections and surveillance.