革兰阴性杆菌中1类整合子的分布与耐药关系

Relationship between class 1 integron and resistance in gram negative bacteria

关键词:  革兰阴性杆菌  整合子  多重耐药

Key words:  gram negative bacteria  integron  multi-drug resistance

摘要:

［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，应加强临床细菌基因水平的耐药监测，采取有效措施防止耐药性的传播。

Abstract:

［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.［Conclusions］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.