产超广谱β-内酰胺酶49株大肠埃希菌耐药基因调查

Study on genotype of extended-spectrum β-lactamases Escherichia coli

目的：探讨我市近2年大肠埃希菌耐药基因的分布及耐药性变化。方法：对49株临床分离鉴定的菌株，通过K—B法药敏试验初筛以确认ESBLs菌株，并对ESBLs基因进行初步分型。结果：49株菌株中有45株产TEM-1型广谱β-内酰胺酶及CTX—M型ESBLs，阳性率为89．6％，包括36株CTX—M-14，10株CTX—M-15，2株CTX—M-3。有5株产2种ESBLs，4株未能确定ESBLs基因型；大肠埃希菌对亚胺培南、哌啦西林／他唑巴坦及头孢他酮／舒巴坦耐药率为0．0～7．0％。结论：温岭地区产ESBLs大肠埃希菌的基因以CTX—M-14型为主，其次为CTX—M-15。

Objective：To investigate the genotype distribution and drug resistance of ESBLs - producing Escherichia coil in our hospital during the last two years. Methods： ESBLs - producing among clinical isolates bacteria was confirmed by K - B initial screening test. The pathogenic bacteria assay and duug resistance test were conduct with ATB microorganism assay. Results：45 strains （91.84%） produced TEM - 1 and CTX - M - type ESBLs,including TEM - 1 ＋ CTX - M - 14（25 strains） ,TEM - 1 ＋ ctx - M - 14 ＋ CTX - M - 15（5 strains）, CTX - M -3（ 1 strains） ,ctx - m - 14（6strains） ,TEM - 1 ＋ CTX - M - 15 （3strains）, CTX - M - 15（2strains） ,TEM - 1 （2strains） andTEM - 1 ＋ CTX - M - 3 （1strains）. 5 strains produced two kinds of ESBLs and another 5 strains were negative by PCR. Escherichia coli were poorly resistant t6 imipenem, piperacillin/tazobactam and cefoperazone/salbactam（0.0 - 7.0% ）. Conclusion： CTX- M -14 is the most common genotype plasmid- mediated ESBLs produced by Escherichia coli Wenling,followed by CTX- M -15.