Genotyping of AmpC Produced by Gram-negative in Infected Children

OBJECTIVE: To investigate the incidence rate of the ampC gene and AmpC enzyme of gram-negative(G-) bacterium in children,to analyze drug resistance of produced AmpC enzyme and un-produced AmpC enzyme strain.METHO_DS: 4 022 clinical G-isolates collected from 2002 to 2004 were identified and tested using K-B method.Selection 108 ESBLs bacterium,the ampC genes were amplified by PCR using common primers to AmpC and the AmpC enzymes were tested using the enzymatic rough extraction cefoxitin three-dimensional test.The drug resistance of bacterium produced AmpC enzymes were compared with the ones without AmpC enzymes.RESULTS: In 108 G-bacterium,the ampC genes positive bacterium were 70 strain(accounting for 64.8%),and 7 bacterium produced AmpC enzymes(accounting for 6.5%) were detected.The drug resistance of bacterium produced AmpC enzymes to ceftazidime(CAZ),ceftriaxone(CRO),piperacillin(PIP),ampicillin(AMP),aztreonam(ATM) were 85.7%,85.7%,71.4%,79.4%,79.4% respectively.The drug resistance of bacterium non-produced AmpC enzymes to CRO,PIP,gentamicin,AMP,ATM were 50.8%,55.6%,55.6%,70.3%,54.0% respectively,the drug resistance of bacterium to imipenem were the lowest,lower to ciprofloxacin.CONCLUSIONS: Detection rate of ampC gene were higher than AmpC-producing enzymes strains obviously,whereas the drug resistance to antibiotic of AmpC-producing enzymes strains were higher than non-producing enzymes strains.