淋球菌临床分离株外膜蛋白PJ基因序列与耐药性关系初探

目的研究成都地区淋球菌临床分离株PI基因序列与青霉素和四环素耐药性的关系。方法用T-A克隆的方法得到PI基因克隆重组子,对PI基因测序后,用序列分析软件进行分析。同时测定青霉素和四环素对淋球菌的最低抑菌浓度,比较耐药性与PI基因序列的相关关系。结果成功克隆并测序淋球菌PI基因,17条PI序列根据blastn结果可分为PIA和PIB两类。序列在影响淋球菌耐药性的第120和121位的氨基酸序列仅有部分发生单位点的D突变,未见文献报道的双位点D突变。5-9、6-1两条序列在120位发生K突变,且2株菌的耐药性均处于中等水平,与文献报道一致。结论成都地区淋球菌临床分离株外膜蛋白PI的序列与染色体介导的青霉素和四环素耐药性可能存在一定的相关关系,是否与PI基因序列120和121位氨基酸残基突变相关,还有待调查更多的临床分离株。

A primary study On the nlationship betwoon amino acid mutations in clinical isolates Neisseria gonorrhoeae and their resistance to antibiotics

Objective To identify the relationship between amino acid mutations in Neisseria gonorrhoeae isolates and their antibiotic resistance.Methods PI gene fragments of Neisseria gonorrhoeae from 17 clinical isolates were obtained with PCR amplification.They were cloned into the PCR cloning vector pBS-T to form pBS-T-PI and sequenced.The sequences of PI genes were analyzed.At the same time,minimum inhibitory concentration (MIC) of penicillin and tetracycline to these 17 isolates were measured and contrasted with the corresponding PI sequence.Results The recombinants of PI gene from 17 clinical isolates of Neisseria gonorrhoeae were successfully constructed and sequenced.They were divided into PIA and PIB subtypes according to the results from blastn software by comparing the sequences with the GenBank.Mutations were found at the sites of 120 and 121.There were only some of the sequences having an aspartic acid (D) mutation on 120 and 121 sites,which was not the same as reported.On the other hand,there were two PI sequences,5-9 and 6-1,whose mutations on No.120 were lysine,similar to those documented.Conclusion Some relationship between PI amino acids mutations at sites 120 and 121 in Neisseria gonorrhoeae isolates from Chengdu,China and their resistance to penicillin and tetracycline were found.However,further studies need to be done in the future to confirm this hypothesis.