多药耐药大肠埃希菌质粒介导的复合β-内酰胺酶耐药基因研究  

Study on plasmid-mediated polygenes in multiple β-lactamase resistant genes in Escherichia coli

作　　者：张正琼 黄永茂[2] 毕义亮 钟利[2] 陈枫[2] 陈庄[2] 史小玲[2] 

机构地区：[1]成都市慢性病医院重症监护病区,四川成都610083 [2]泸州市泸州医学院附属医院感染科,四川泸州646000

出　　处：《中华医院感染学杂志》2015年第18期4088-4091,共4页Chinese Journal of Nosocomiology

基　　金：四川省重点学科重点建设基金资助项目(SZD0241)

摘　　要：目的研究泸州地区质粒介导的产β-内酰胺酶多药耐药大肠埃希菌TEM、SHV、CTX-M、CTX-M-3、CTX-M-22、CTX-M-24等耐药酶复合基因分布及对常见抗菌药物的耐药性。方法采用美国临床实验室标准化委员会(NCCLS)2006年推荐的方法,测定71株大肠埃希菌对常见的氨基糖苷类、氟喹诺酮类、第三代头孢菌素类的耐药性;采用质粒小提试剂盒制备质粒DNA扩增模板,PCR技术扩增6种基因,产物琼脂糖凝胶电泳,以标准菌株大肠埃希菌ATCC 25922进行阴性对照,基因测序仪检测碱基序列。结果临床分离的71株大肠埃希菌中多药耐药菌30株占42.86%;含两种酶基因同时检出的有30株,其中CTX-M+CTX-M-3有12株占40.0%,CTX-M-24+CTX-M有12株占40.0%;CTX-M-22+CTX-M-24有6株占20.0%;含3种耐药酶基因共检出13株占32.5%;携带CTX-M-24、CTX-M-3、TEM、CTX-M、CTX-M-24+CTX-M基因的菌株对阿米卡星和妥布霉素的耐药率差异有统计学意义(P<0.05);携带TEM、CTX-M、CTX-M-3基因的菌株对头孢呋辛和头孢哌酮的耐药率差异有统计学意义(P<0.05)。结论复合酶基因中主要CTX-M+CTX-M-3、CTX-M+CTX-M-24为主,以及在同一菌株质粒上出现3种不同的基因型。OBJECTIVE To investigate ESBLs-producing polygenes and drug-resistance of CTX-M-22,CTX-M-24,CTX-M,CTX-M-3,SHV,TEMin plasmid-mediated multiple-drug resistant Escherichia coli（E.coli）.METHODS The Kerby-Bauer disk diffusion method from the National Committee for Clinical Laboratory Standards（NCCLS）of America was used to test drug-resistance of 71 strains of E.coli against antibacterials including cephalosporins,fluoquinolones and third-generation cephalosporins.The plasmid minipreparation kit was used to prepare DNA amplification template.CTX-M-22,CTX-24,CTX-M,CTX-M-3,SHV,TEM genes were amplified by PCR technique and the products were performed with agarose gel electrophoresis and sequencing and compared with the standard E.coli ATCC 25922 for negative control and the gene sequenator was used to detect base sequence.RESULTS There were 30 multiple-drug resistant strains（42.86%）among the 71 clinical isolated strains.There were 30 strains with two enzyme genes co-detected,including 12 strains with CTX-M ＋CTX-M-3（40.0%）,12 strains with CTX-M-24＋CTX-M（40.0%）,and 6strains with CTX-M-22＋CTX-M-24（20.0%）.There were 13 strains detected with three kinds of resistant genes（32.5%）.The difference was significant in resistances to amikacin and tobramycin between strains carrying CTX-M-24,CTX-M-3,TEM,CTX-M,CTX-M-24＋CTX-M genes（P〈0.05）.The difference was significant in resistances to ceftriaxone and cefoperazone between strains carrying TEM,CTX-M,CTX-M-3genes（P〈0.05）.CONCLUSIONThe major polygenes in multi ESBLs-producing strains were CTX-M＋CTX-M-3,and CTX-M-24＋CTX-M and the special case was that 3kinds of different genotypes coexisted at the plasmid of one strain.

关 键 词：大肠埃希菌 多药耐药 质粒介导 Β-内酰胺酶基因 

分 类 号：R378.11[医药卫生—病原生物学]