大肠埃希菌所致儿童急性腹泻流行病学调查及耐药性分析

Epidemiological investigation and drug resistance analysis in children with acute diarrhea caused by Escherichia coli

目的分析大肠埃希菌在急性腹泻儿童中的流行病学和耐药性特征。方法收集2019年1-12月期间于芜湖市第五人民医院就诊的564例急性腹泻儿童的粪便样本,培养后鉴定,用PCR法扩增大肠埃希菌的毒力基因uida、eae、agg R、bfp B、esc V、stx1,用血清凝集法鉴定致病性大肠埃希菌,用琼脂稀释法进行常见抗生素的药敏试验。结果从564份粪便样本中分离到123株病原菌,分离率为21.81%。主要有沙门菌48株、大肠埃希菌45株、空肠弯曲菌18株,构成比分别为8.51%、7.98%、3.19%。大肠埃希菌导致的急性腹泻有显著的季节性及年龄特征,夏秋两季为发病高峰期,在年龄分布上呈年龄越小检出率越高的趋势。45株大肠埃希菌中有致病性大肠埃希菌23株,其中9株血清凝集试验阳性。23株致病性大肠埃希菌经毒力基因扩增,鉴定到9株肠聚集性大肠埃希菌、7株肠产毒性大肠埃希菌、1株肠侵袭性大肠埃希菌。45株大肠埃希菌对复方磺胺甲噁唑、环丙沙星、氨苄西林、头孢唑啉、头孢噻肟、头孢呋辛的耐药率均在50%以上。结论大肠埃希菌是急性腹泻儿童常见的致病菌之一,对常用的一线抗生素耐药率较高,临床需结合药敏试验选择敏感的抗生素。

Objective To investigate the epidemiological and drug resistance characteristics of children with acute diarrhea caused by Escherichia coli. Methods The fecal samples were collected from 564 children with acute diarrhea who attended to Fifth People’s Hospital of Wuhu from January to December 2019,PCR was used to amplify the virulence genes(uida,eae,agg R,bfp B,esc V and stx1) of E. coli after culture and identification. The serum agglutination method was used to identify pathogenic E. coli strains,and the agar dilution method was used to perform drug sensitivity test to investigate the sensitivity to commonly used antibiotics. Results A total of 123 pathogenic strains were isolated from the 564 fecal samples,with an isolation rate of 21.81%,among which there were48 Salmonella strains,45 E. coli strains,and 18 Campylobacter jejuni strains,with constituent ratios of 8.51%,7.98%,and 3.19%,respectively. Acute diarrhea caused by E. coli showed significant seasonal and age characteristics,with the highest incidence rate in summer and autumn,and as for age distribution,the younger the age,the higher the detection rate. Among the 45 strains of E. coli,there were 23 pathogenic strains,among which 9 strains were tested positive by the serum agglutination test. After the virulence genes were amplified for the 23 pathogenic E. coli strains,there were 9 strains of EAEC,7 strains of ETEC,and 1 strain of EIEC. All 45 E. coli strains had a drug resistance rate of above 50% to compound sulfamethoxazole,ciprofloxacin,ampicillin,cefazolin,cefotaxime,and cefuroxime.Conclusion Escherichia coli is one of the common pathogenic bacteria in children with acute diarrhea,with a relatively high drug resistance rate to commonly used first-line antibiotics. Sensitive antibiotics should be selected based on drug sensitivity test in clinical practice.