OXA-50型碳青霉烯酶基因在铜绿假单胞菌中分布的初步研究

Research on the distribution of OXA-50 gene in carbapenems-resistant Pseudomonas aeruginosas

目的研究铜绿假单胞菌(Pseudomonas aeruginosa,PA)对碳青霉烯类抗生素耐药的分子机制。方法收集非重复34株铜绿假单胞菌临床株,PCR扩增blaOXA-50基因、测序、在GenBank上比对、提取质粒DNA、对该基因进行PCR扩增。结果PCR检测出34株铜绿假单胞菌中有15株含OXA-50型基因,其中30株耐亚胺培南的铜绿假单胞菌中有12株阳性,4株敏感菌中亦有3株阳性;随机选取1株阳性菌PCR产物送测序,测序结果在GenBank上进行blast比对,显示有两个突变点;blaOXA-50基因扩增阳性的15株铜绿假单胞菌,提取质粒DNA扩增该基因,结果为阴性。结论本次实验检测了34株铜绿假单胞菌临床株,OXA-50型基因的检出率为44.10%,其中1株发现有两个位点突变;检测到的blaOXA-50编码基因位于染色体上。

Objective To study the distribution of OXA-50 gene in Pseudornonas aeruginosa. Methods A total of 34 isolated clinical strains of Pseudomonas aeruginosa were subjected to PCR analysis with primers specific for blaOXA-50, which was used for comparing the sequence results with corresponding sequences in GeneBank, then plasmid DNA of positive strains for PCR was extracted. Results 15 isolated strains showed positive results for blaoxAso detection, 12 strains were identified in carbapenems-resistant Pseudomonas aeruginosas, and 3 strains were detected in carbapenems-sensitive Pseudomonas aeruginosa; the sequencing result of one positive strain showed that there were two mutational sites, and the PCR for plasmid DNA of all positive strains were negative. Conclusions In this experiment, the detection rate of blaOXA-50 was 44.10%, there were two mutational sites in one of positive strains, and all the blaOXA-50 were located in chromosome.