摘要
目的：了解本院男性泌尿系感染产超广谱β-内酰胺酶（ESBLs）和AmpC酶大肠埃希菌（E．coli）的基因型分布。方法：收集2004年1月～2005年6月本院临床分离的尿培养阳性大肠埃希菌共187株，用CLSI／NCCLS推荐的纸片扩散法（包括筛选和确认实验）进行耐药表型检测，三维酶试验检测ESBLs和AmpC酶，PCR扩增质粒型ESBLs和ampC基因，肉汤交配法检测质粒型ampC基因的接合传递性。结果：产ESBLs大肠埃希菌检出率为24．6％（46／187）。在三维试验中，46株均产分解头孢三嗪（CRO）的β-内酰胺酶，其中3株产ESBLs和AmpC两种酶，其余43株单产ESBLs酶。在PCR扩增试验中，44株扩增出ESBLs基因blaTEM、blaCTX-M、blaOXA3型中的1型或1型以上基因片段，未扩增出blaSHV型基因片段；3株扩增出质粒介导的ampC基因，2株为CIT型，1株为DHA型。携带质粒型ampC基因的菌株均将耐药性传递给受体菌。结论：南京地区男性泌尿系感染产ESBLs大肠埃希菌以CTX-M型为主；质粒介导AmpC酶已在大肠埃希菌中出现，其耐药性能够水平传播，给临床抗感染治疗带来严重威胁。
Objective： To study the genotype distribution of extended-spectrum β-1actamases （ESBLs） and AmpC β-1actamases produced in E. coli isolated from men with urinary infection in Nanjing. Methods ： Organisms of clinical infection were identified by auto- matic microbial system （Vitek-32）. ESBLs were detected by disk diffusion confirmatory test, and ESBLs and AmpC β-1actamases by three-dimensional extract test （TDET） , the presence of plasmid-mediated ESBLs and ampC genes determined by PCR, and conjugal transfer assays of the ampC resistance determinants carried out by a broth mating procedure. Results： ESBLs were produced in 24.6% （46/187） of the E. coli and the 46 E. coli isolates showed β-1actamase activity in TDET, 3 positive for both ESBLs and AmpC β-lactamases and 43 for ESBLs only. Forty-four of the 46 isolates were shown by PCR to contain at least one of the genes blaTEM, blaOXA, blaCTX-M , but no blaSHA. AmpC specific amplication products were observed in 3 of the 46 isolates, of which 2 were of CIT type, and 1 of DHA type. All of the 3 transconjugants transferred the plasmids harbouring ampC genes to recipients. Conclusion： CTX-M is the most common genotype in plasmid-mediated ESBLs produced by E. coli isolated from men with urinary infection in Nan-jing. Present findings indicate that AmpC-producing E. coli are present in this hospital, and ampC-encoding plasmids are transferable.
出处
《中华男科学杂志》
CAS
CSCD
2006年第11期1000-1003,共4页
National Journal of Andrology
基金
江苏省医学重点学科基金资助项目(苏卫科教[2001]34)
