【摘要】 目的研究产超广谱β-内酰胺酶(ESBLs)大肠埃希菌和肺炎克雷伯菌整合子分布及其在ESBLs基因水平转移中的作用。方法采用PCR方法检测230株产ESBLs和197株非产ESBLs大肠埃希菌和肺炎克雷伯菌Ⅰ类整合酶基因intⅠ,分析Ⅰ类整合子与细菌耐药性的关系,与blaSHV、blaCTX和blaTEM编码基因的关联及经质粒转移的情况。结果产ESBLs和非产ESBLs菌株中Ⅰ类整合酶扩增阳性例数分别是137例(59.6%)和48例(24.4%),两组整合子阳性率差异有统计学意义(P<0.01);整合子阳性株对喹喏酮类、氨基糖苷类以及二者同时耐药的比率较高,依次为82.5%、81.8%和71.5%;产ESBLs菌株中blaSHV、blaCTX和blaTEM基因与整合子经质粒共同转移的频率分别是59.5%、95.5%和69.5%。结论Ⅰ类整合子在产ESBLs大肠埃希菌和肺炎克雷伯菌中的分布明显高于非产ESBLs菌株,并参与产ESBLs菌株多重耐药性的形成;整合子与blaCTX经质粒共同转移的频率高于其他两类基因,提示CTX型酶具有更强的扩散优势。更多还原

【Abstract】 OBJECTIVE To survey the distribution of class Ⅰ integron in extended-spectrum beta-lactamases(ESBLs)-producing Escherichia coli and Klebsiella pneumoniae and its contribution in horizontal transfer of ESBLs genes.METHODS The presence of class Ⅰ integron among 230 ESBLs-producers and 197 non-ESBLs-producers of E.coli and K.pneumoniae were detected by PCR.The correlation and co-transfer between integron and genes coding for SHV,CTX and TEM were studied. RESULTS One hundred and thirty-seven(59.6%) isolates were positive for intⅠ gene among ESBLs-producers,contrasted to 48(24.4%) in non-ESBLs-producers(P<0.001).Strains positive for intⅠ were related to multidrug resistance with higher resistant rates to aminoglycosides and/or fluoroquinolones.The rates of transconjugation of integron together with blaSHV,blaCTX and blaTEM were 59.5%,95.5% and 69.5%,respectively.CONCLUSIONS Distribution of class Ⅰ integron in ESBLs-producing strains is more predominant than that in non-ESBLs-producers.It contributes to multidrug resistance in ESBLs-producing strains.blaCTX Are more liable to transfer via plasmid along with class Ⅰ integron.更多还原