The Mechanisms Of Drug-resistance And Epidemiology Of Escherichia Coli Producing Extended-spectrumβ-lactamases In Taiyuan Area

Objective:Investigate the mechanisms of drug-resistance and epidemiology of Escherichia coli.These strains producing extended-spectrumβ-lactamases come from taiyuan. With a view to provide the experimental reference and guideline for judicious use of antibiotics.Methods:1.ESBLs-producing strains were confirmed by the NCCLS phenotypic confirmatory test using disc agar diffusion method (Kirby-Bauer diffusion test).2. PCR amplification of ESBLs genes, then direct analysis DNA sequencing.3.Using three-dimension method and mutiPCR detection of AmpC-β-lactamases . The strains were cefoxitin drug-resistance.4.Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) isolation and analysis outer membrane protein of some strains.5. Useing ERIC2-PCR analysis epidemiological investigations. 6.PCR amplification of integrase and Genecassettes genes, then direct DNA sequencing analysis.Results1. 68 ESBLs-producing strains were confirmed by the NCCLS phenotypic confirmatory test using Kirby-Bauer diffusion test.10 strains isolation from outpatient ,other isolation from inpatients ,surgery ward accounting for 2/3.2 .The PCR results of gene in plasmid DNA showed that TEM positive was 67 strains, The sequence showed 100% amino acid identity to TEM-1. SHV positive was 04LE30, The sequence showed identity to SHV-12. CTX-M2,OXA1,OXA2,OXA10 all are negative. CTX-M 1 showed 21 strains positive .CTX-M 9 positive was 48 strains.3 .Detection three-dimension method of AmpC-β-lactamases ,04LE30 was positive,mutiPCR show a bind at 400bp ,The sequence showed identity to DHA1.4. Omp profile analysis showed that OmpF expression presented diminution or deletion in some ESBL-producing strains.04LE048 OmpC expression presented deletion and has a new...