革兰阴性杆菌中1类整合子的分布与耐药关系

目的]在革兰阴性杆菌中检测1类整合子,并分析整合子对细菌耐药性的影响.方法]用VITEK-AMS微生物自动分析仪鉴定细菌和药敏试验,用PCR方法扩增1类整合酶基因,经电泳后检测扩增产物.结果]266株革兰阴性细菌中检测出1类整合子66株,检出率为24.8%.主要阳性菌为大肠埃希菌34.3%(24/70)、肺炎克雷伯菌48.1%(26/54)、阴沟肠杆菌30%(6/20)、铜绿假单胞菌15.6%(7/45)、鲍曼不动杆菌4.8%(2/42)、产气肠杆菌20%(1/5).1类整合子阳性菌对氨基糖苷类、喹诺酮类及头孢菌素类药物表现出较高的耐药率.携带1类整合子菌株易表现出对至少4种抗菌素的多重耐药性,其多重耐药率为68.2%(45/66),明显高于1类整合子阴性菌株(28.5%),P＜0.05.结论]1类整合子广泛地存在革兰阴性细菌中,1类整合子对细菌多重耐药性的产生和传播起着重要作用,应加强临床细茵基因水平的耐药监测,采取有效措施防止耐药性的传播.

Relationship between class 1 integron and resistance in gram negative bacteria

Objective] To study the distribution of the class 1 integrons in gram negative bacteria and evaluate the class 1 integrons to the antibiotic resistance.Methods] MICs of 13 different antimicrobial agents against 266 isolates of gram negative bacteria were determined by VITEK GNS card.The presence of class 1 integrase gene was determined by polymerase chain response(PCR) with integrase specific primer and examined by electrophoresis.Results] The positive rate of class 1 integron is 24.8%(66/266) in gram negative bacteria.Enterobacter coli,Klebsiella pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,Acinetobacter baumannii and Enterobacter aerogenes accounted for was 34.3%(24/70),48.1%(26/54),30%(6/20),15.6%(7/45),4.8%(2/42) and 20%(1/5),respectively.Similarly on the basis of 9 antibiotics in the group with class 1 integrons were higher than that in none-group(P<0.05).All the integron-positive strains were resistance to at least 4 antibiotics.In the group with class 1 integrons the multi-drugs resistance rate was 68.2%,but in the none-group was 28.5%,the difference of the rates between two groups was significant(P<0.05).Resistant rate of integron-positive strains to aminoglocosides,fluroquinolone and cephalosporins was higher.Conclusion] Our study suggests that integron exist in the gram negative bacteria widely.The antibiotics resistance of the integrons positive strains were than higher that of the negative ones.