铜绿假单胞菌耐亚胺培南相关基因OprD_2研究

A Study of the OprD_(2) Gene of Pseudomonas Aeruginosa in Relation to Its Tolerance to Imipenem

目的研究铜绿假单胞菌对亚胺培南的耐药机制。方法取临床分离的铜绿假单胞菌18株,经K-B法检测耐药性,根据耐药性分为耐亚胺培南菌组12株和敏感菌组6株。另设1标准菌株ATCC27853。采用PCR法检测各菌株的OprD2基因,探讨OprD2基因突变与细菌对亚胺培南耐药之间的关系。结果12株耐药菌经OprD2基因扩增,8株阴性,4株阳性;6株敏感菌株及标准菌株扩增全部为阳性。统计学检验结果表明,对亚胺培南耐药菌组和敏感菌组OprD2基因阳性率的差异有极显著性(P<0.01),且在耐药菌中发现了新的OprD2基因突变方式。结论OprD2突变是铜绿假单胞菌对亚胺培南耐药的重要机制,突变的方式有缺失突变与插入失活。

Objective To study the gene-level mechanism underlying the imipenem-resistance of pseudomonas aeruginosa（PA）. Methods A PCR method was used to detect the OprD2 gene in PA. The relationship between the mutation of OprD2 and drug-tolerance of the bacteria was investigated in 12 strains of imipenem-resistant and 6 strains of imipenemsensitive PA isolated in the clinic. Meanwhile, a standard strain of PA ATCC27853 was also studied. The results were analyzed with the Chi-square test. Results 8 of 12 strains of imipenem-tolerant PA were shown to be negative for the OprD2 gene while 4 of them were positive. In contrast, all of the 6 strains of the imipenem-sensitive PA were found to be positive for the OprD2 gene, and so was the standard strain ATCC27853. The results of Chi-square test revealed that the difference between the positive rates of the OprD2 gene in the imipenem-tolerant and sensitive PA was statistically highly significant. Besides, a new type of the OprD2 mutation was discovered in the drug-tolerant PA. Conclusion Mutation of OprD2 was shown to be an important mechanism underlying the imipenem-tolerance of PA. 2 types of OprD2 mutation were found in the study, the deletion mutation and the insertion mutation.