200株血流感染大肠埃希菌耐药性分析

Relationship between ESBL genotyping of Escherichia coli and integron in Anning

目的了解安宁地区产超广谱β-内酰胺酶(ESBL)大肠埃希菌基因分型及其与整合子的关系,掌握大肠埃希菌耐药特点及流行趋势,为临床治疗提供参考。方法收集住院患者大肠埃希菌临床分离株200株,进行菌种鉴定和体外药物敏感性试验。采用纸片扩散法检测ESBL菌株,并通过双纸片法进行确认。采用聚合酶链反应(PCR)检测ESBL基因型别,同时扩增整合子5、3及保守区Ⅰ类、Ⅱ类、Ⅲ类整合酶基因,进行整合子测序分类。结果200株大肠埃希菌中,有118株(59.00%)检出ESBL阳性,88.98%(105/118)扩增到ESBL基因,9.30%(11/118)株同时检出2种ESBL基因。118株ESBL阳性菌株中,CTX-M型的阳性检出率最高(52.54%)。不同基因型大肠埃希菌中,仅检出Ⅰ类整合子,其中CTX-M-1型携带Ⅰ类整合子的菌株所占比例最高(72.41%),SHV型携带Ⅰ类整合子的菌株所占比例最低(50.00%)。大肠埃希菌对氨苄西林-舒巴坦的耐药率最高(83.23%),对亚胺培南的敏感率最高(97.42%)。结论安宁地区大肠埃希菌产ESBL率较高,基因型主要以CXT-M为主,携带多种ESBL基因的菌株主要以携带Ⅰ类整合子为主。

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 ofⅠ,ⅡandⅢintegrase 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 ESBLsproducing 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.