Detection of AmpC and ESBLs of Escherichia coli from community and nosocomial infection and the drug-resistance analysis

Objective To evaluate AmpC and extended-spectrum β-lactamases(ESBLs) produced by Escherichia coli from community and nosocomial infection and drug resistance to commonly used antimicrobial agents,so as to guide the rational use of antimicrobial agents.Methods AmpC was detected by cefoxitin three dimensional extraction test,ESBLs-producing strains were confirmed by double disc synergy and disc confirmatory test.Results The producing rate of AmpC,ESBLs and AmpC+ESBLs in 143 strains of Escherichia coli was 4.90%,28.67% and 2.10% respectively.Drug-resistant rate of non-enzyme-producing strains in nosocomial and community infection was 35.36% and 21.85% respectively,there was significant difference between the two(P0.05);drug-resistant rate of enzyme-producing strains in nosocomial and community infections was 73.40% and 75.60% respectively,there was no significant difference between the two(P0.05).Drug resistant rate of non-enzymes-producing strains in community and nosocomial infection to ampicillin,piperacillin,cefazolin and ciprofloxacin were all high,which was 57.58%,39.39%,42.42%,39.39% and 77.97%,71.19%,66.10%,54.24% respectively;the resistant rates of enzymes-producing strains were higher than the above average resistant rate,among all detected antimicrobial agents,imipenem/cilastatin was the most sensitive drug,there was no imipenem/cilastatin-resistant strains.Conclusion Enzyme-producing rate of Escherichia coli in community infection is obviously lower than that of nosocomial infection,AmpC and ESBLs are the main factors for drug resistance,imipenem/cilastatin is the first choice antimicrobial agents for the treatment of infection with enzyme-producing Escherichia coli.