解脲支原体药敏与tetM基因检测及生物群的研究

Study on Drugs Susceptibility,tetM Gene Determination and Biotypes of Ureaplasma Urealyticum

目的 了解泌尿生殖道支原体的耐药性机理 ,指导临床治疗。方法 采用微量肉汤稀释法测定 2 81株UU对 5种抗菌药物的最低抑菌浓度 (MIC) ,用PCR法扩增tetM基因并酶切 ,用UUMB抗原基因引物对tetM基因阳性UU株进行生物群的研究。结果 2 81株UU中 82株对四环素MIC为 16～ 2 5 6μg/ml ,3 9株为 8μg/ml ,7株为 4μg/ml,15 3 株MIC <4μg/ml;12 1株MIC≥ 8μg/ml及 2株MIC =4μg/ml者均出现 3 77bptetM基因阳性带 ;阳性检测率为 43 .77%。15 8株UUMIC≤ 4μg/ml未见类似扩增带。扩增产物用HpaⅡ酶切和电泳分析 ,均产生 2 79bp和 98bp两个特异性片段。2 81株UU用群特异性PCR分析 ,生物群 1有 166株 ,生物群 2有 115株 ;12 3株tetM阳性UU株 ,属生物群 1、2者分别有 5 4株和 69株 ,分别占 3 2 .5 3 % ( 5 4/166)和 60 .0 % ( 69/115 ) ( χ2 =7.94,P <0 .0 5 )。结论 ①PCR技术检测泌尿生殖道感染患者UU耐药性tetM基因具有特异、敏感、快速等优点 ;②载有tetM基因的UU株可能成为四环素耐药株 ,应进行监测及随访 ;③我国衡阳地区UU四环素耐药株以生物群 2占优势。

Objective To monitor resistance of urogenital mycoplasma periodically,and to instruct rational application of antibiotics clinically.Methods The minimal inhibitory concentrations(MICs) of 281 strains UU to 5 kinds of antimicrobial agents were determined using microbroth dilution assay,the tetM gene in the isolates was detected by PCR and the PCR products were digested by HpaⅡ restrictive endonuclease.PCR analysis was used to sutdy the biotypes of UU with tetM gene with primers derived from MB antigen gene.Results Of 281 strains UU tested,82 strains,which MIC were≥16～256μg/ml,39 MIC=8μg/ml,7MIC=4μg/ml and 153,MIC<4μg/ml.A 377bp PCR amplified product was found in 121 strains UU which MIC≥8μg/ml,2 strains,MIC=4μg/ml also gave PCR products of the appropriate size.The positive rate of tetM was 43.77%.158 strains MIC≤4μg/ml failed to give PCR products.The products of PCR were digested with restriction enzyme and gave rise to 279bp and 98bp two fragments.Biotype-specific PCR was used for 281 strains UU,166 strains were classified as biotype 1,and 115 strains were classfied as biotype 2.123 strains UU with tetM gene,the strains classified as biotype 1 and biotype 2 were 54and 69 respectively,the percentage was 32.53%(54/166) and 60.0%(69/115) respectively.Conclusion ①PCR technique has specific,sensitive,rapid advantages for tetM gene detection of UU in patients with urogenital infections.②UU strains carrying tetM gene might become drug resistent ones which should be monitored and followed up with MIC determination.③Biotype 2 is the dominant srains of the tetracycline-resistant UU in Heng Yang.