多重耐药性大肠埃希菌质粒谱与ESBLs基因型分析  

Antibiotic plasmid profile and genotypes of extended-spectrum β-lactamase producers in multit-drug resistant Escherichia coli

作　　者：张洁[1] 包其郁[1] 张洪勤[1] 李佩珍[1] 豆长明[1] 张寿国[2] 

机构地区：[1]温州医学院,温州325001 [2]温州市第二人民医院,温州325001

出　　处：《中国抗生素杂志》2006年第4期198-201,共4页Chinese Journal of Antibiotics

摘　　要：目的分析临床耐药大肠埃希菌质粒谱与基因型间关系,确定超广谱β-内酰胺酶e(xtended spectrum bata lactarnase,ESBLs)基因在细菌质粒谱上的座位。方法分离鉴定菌株,通过KB-法药敏实验确认产ESBLs菌株。凝胶电泳检测菌体质粒,并应用PCR技术扩增ESBLs基因。结果分离到产ESBLs细菌128株,检出率为78.0%,针对12种抗生素,产ESBLs细菌的耐药率在29%～71%之间;128株大肠埃希菌含11类不同谱型的质粒群,其中较大质粒(23kb、9.4kb)出现频率高(71.1%、26.6%);PCR分型结果显示,单独携带TEM型ESBLs基因的菌株比例为24.2%,SH V型为19.5%,CTXM-型为53.1%,携带两种基因型以上的占18.8%。CTXM-型中三个亚型CTXM--24、CTXM--22型和CTXM--3型比例分别是32.0%、28.1%和17.2%。结论质粒谱中,某些分子量相同或相近的较大质粒能稳定存在于菌体内并能导致相应耐药性的产生和播散。定位这类质粒上ESBLs基因的差异导致了菌株耐药性的不同。Objective To investigate the relationship of ESBLs gene type and antibiotic plasmids profile in muhidmg resistant strains isolated from clinical samples. Methods Drug susceptibility were performed by Kirby-Bauer disk diffusion tests, plasmid profiles were detected by agarose electrophoresis, and the types of ESBLs- encoding genes were analyzed by the polymerase chain reaction （PCR）. Results The positive rate of ESBLs-producing isolates in Escherichia. coli was 78.0% （128 strains）. The resistant rates of ESBLs producing isolates against 12 different antibiotics were from 29% to 71%. In Wenzhou area, 11 plasmid patterns were identified from 128 isolates. Some large plasmids （23kb,9.4 kb） with higher frequency （71.1%, 21.9% ） in plasmid patterns were all multidrug resistant. The study revealed that TEM, SHV, CTX-M and multi-ESBLs genotypes were 24.2%, 19.5%, 53.1% and 18. 8 % respectively. Subtype CTX-M-24,CTX-M-22 and CTX-M-3 were 32. 0% ,28.1% and 17.2% respective- ly. Conclusions In plasmid profile, some large plasmids （23kb, 9.4 kb） and those similar molecular weight might exist in the bacteria and become resistant strains, however different ESBLs genes located on those large plasmids （23kb,9.4 kb） resulted in different multiple resistant types.

关 键 词：大肠埃希菌 Β-内酰胺酶 耐药性 基因分型 质粒 

分 类 号：R378.21[医药卫生—病原生物学]