产超广谱β-内酰胺酶大肠埃希菌I类整合子检测与耐药性关系

Relationship between class 1 integron and resistance in clinical ESBLs-producing Escherichia coli strains

目的了解I类整合子在产ESBLs和非产ESBLs大肠埃希菌中分布状况,分析I类整合子在细菌多重耐药中的作用。方法用PCR方法扩增I类整合酶基因,经电泳后检测扩增产物。用2χ检验进行统计学分析,P<0.05为差异有显著性。结果105株大肠埃希菌检出I类整合子46株,检出率为43.8%。I类整合子在产ESBLs菌的检出率为53.4%,明显高于非产ESBLs菌(31.9%),2χ检验,P<0.01。I类整合子阳性菌株多重耐药率为68.8%(33/48),明显高于阴性菌株(33.3%),P<0.05。I类整合子阳性菌株和产ESBLs菌均对青霉素类、喹诺酮类、磺胺类抗生素表现出较高的耐药率。所有菌株均对亚胺培南敏感。结论I类整合子携带与产ESBLs菌株耐药有关,I类整合子阳性菌株对多种抗生素的耐药率大于整合子阴性菌株。

Objectives To investigate the distribution of class 1 integrise gene among all ESBL-producing and non-ESBL-producing Escherichia coli isolates from patients attending and to evaluate the class 1 integrons to the antibiotic resistance associated with ESBL-producing organisms. Methods The presence of class 1 integmse gene was determined by Polymerase Chain Response（PCR） with integrase specific primer and examined by electrophoresis. Statistic significance for comparison proportions was calculated by the chi-square test. P〈0.05 was considered to be statistically significant. Results 46 of 105 isolates were identified as being positive for integrase 1 gene,positive rate was 43.8%. The class 1 integron were more frequently found among c-ESBLs（53.4% ） than among c-nESBLs（31.9% ） Escherichia coli strains（ P 〈 0.01 ）. In the group with class 1 integron the multi-drug resistance rate was 68.8% ,while in the none-group was 33.3% , the difference of the rates between the two groups was significant（ P〈0.05 ）. Resistant rate of integron-positive strains and ESBLs-producing isolates to penicillins, fluroquinolone and sulfonamide high. However,impenem showed good antimicrobial activity among all these Escherichia coli strains. Conclusions There was a good correlation between integron-carrying and the ESBLs-producing of Escherichia coli strains. The antibiotics resistance of the integron positive strains was higher than that of the negative ones.