Abstract:

Objective To understand the relationship between extended-spectrum lactamases（ESBL） genotyping of Escherichia coli and integron in Anning,to evaluate the characteristics and prevalence of Escherichia coli drug resistance,and to provide a reference for the treatment and control of Escherichia coli producing ESBL. Methods A total of 200 isolates of Escherichia coli were collected. Isolate identification was performed,and drug susceptibility test was performed in vitro. ESBL isolates were determined by disc diffusion method and confirmed by double disk method. ESBL genotyping was determined by polymerase chain reaction（PCR）. Integron 5 and 3 and conservative district of Ⅰ,Ⅱ and Ⅲ integrase genes were amplified,and integrates were sequenced and classified. Results Among the 200 isoaltes of Escherichia coli,the positive rate of ESBL was 59.00%（118/200）. ESBL genotype were amplified in 105 isolates of ESBL,accounting for 88.98%. Two or more ESBL genes were determined in 11 isolates,accounting for 9.30%. CTX-M type had the highest determination rate（52.54%）. Among 118 ESBLs-producing strains,the positive detection rate of CTX-M type was the highest 52.54%. Only I class integron was determined from different positive genotype amplification bacteria. ⅠCTX-M-1 type isolate carried I class integron accounting for 72.41%,while SHV type isolate carried I class integron accounting for 50.00%. Conclusions The positive rate of ESBL of Escherichia coli in Anning is relatively high. CXT-M gene is the dominant genotype. The isolates carrying multiple ESBL genes show a gradual increase trend,and the main type is I integron.

Key words: Escherichia coli, Extended-spectrum lactamase, Genotyping, Integrase