老年患者泌尿道大肠埃希菌的耐药分析及基因型研究

Drug resistance and genotypes of Escherichia coliin elderly patients with urinary tract infections

目的探讨老年患者泌尿系统感染的菌群分布、大肠埃希菌的耐药性及产超广谱β-内酰胺酶(ESBLs)的基因分型。方法对731份泌尿道感染的老年患者尿液标本进行分离培养,用K-B法进行药敏分析,筛选产ESBLs菌株并用PCR的方法鉴定基因型。结果培养出细菌共198株,以大肠埃希菌为主占52.5%;大肠埃希菌耐药严重,仅对亚胺培南、哌拉西林/他唑巴坦、阿米卡星及呋喃妥因较敏感,其中有54.8%的菌株产ESBLs,产ESBLs菌株耐药率较非产ESBLs菌株高;而且ESBLs基因型多以CTX-M-14和CTX-M-1为主,且40.3%的菌株存在>2种的基因型。结论老年患者泌尿道感染的病原菌耐药性严重且机制复杂,应定期监测病原菌的耐药趋势,以指导临床医师合理应用抗菌药物。

OBJECTIVE To investigate the bacterial distribution,drug resistance of Escherichia coli and genotypes of extended spectrum β-lactamases（ESBLs） in elderly patients with urinary tract infections.METHODS A total of 731 urine specimens obtained from the elderly patients with urinary tract infections were cultured,the drug susceptibility testing was performed by K-B method.ESBLs-producing strains were screened and the genotypes were identified by PCR.RESULTS Of 198 strains of bacteria isolated,E.coli accounted for 52.5%;the drug resistance of E.coli was serious,E.coli was only susceptible to imipenem,piperacillin/tazobactam,amikacin and nitrofurantoin;54.8% of the isolates were ESBLs-producing strains,the drug resistance rate of ESBLs-producing strains was higher than that of non-ESBLs-producing strains;CTX-M-14 and CTX-M-1 were the major genotypes of ESBLs,and 40.3% of the strains carried more than 2 genotypes.CONCLUSION The drug resistance of the pathogens causing urinary tract infections in elderly patients is serious and the resistant mechanism is complex;regular surveillance of the trend of the drug resistance should be performed so as to guide the reasonable use of antibiotics.