目的探讨目前解脲脲原体对四环素类药物的耐药性及其与tetM耐药基因的关系。方法对分离自临床妇产科和性病门诊患者的解脲脲原体株,经鉴定确认后,采用微量肉汤稀释法检测其四环素和米诺环素的最小抑菌浓度(MIC),根据药敏结果分层随机抽取部分菌株,采用PCR技术扩增四环素耐药基因tetM。结果解脲脲原体的米诺环素和四环素MIC50(50%菌株被抑制所需抗生素浓度)分别为〈0.0625mg/L和〈0.125mg/L)MIC50(90%菌株被抑制所需抗生素浓度)分别为0.125mg/L和1mg/L)在34株非四环素耐药的解脲脲原体菌株中,有7株检测到tetM基因。tetM基因阳性组的四环素和米诺环素的MIC水平比tetM阴性组高,且差异有统计学意义(四环素:t=4.34,P=0.0001;米诺环素:t=5.90,P〈0.0001)。结论在江苏部分地区四环素类药物可以重新作为治疗解脲脲原体感染的一线药物,尤其是米诺环素的抗菌效果较好;在非四环素耐药的解脲脲原体菌株中也存在tetM基因的携带,且影响其MIC的提高。
To determine the relationship of the drug resistance of tetracyclines of Ureaplasma urealyticus and the distribution of the resistance gene tetM, the in vitro susceptibility to tetracycline and minocycline of 84 strains of U. urealyticus from clinical isolates was determined by broth microdilution method, and based on the susceptibility tested, the resistance gene term from 34 strains of U. urealyticus were amplified by PCR. It was found the MIC50 s to tetracycle and minomycyline were 0. 0625 mg/L and 〈 0. 0125 mg/L respectively, and the MICros to these two antibiotics were 0. 125 mg/L and 1 mg/L respectively. Meanwhile, in these 34 strains of the non-resistant U. urealyticus, 7 strains were to be detected term gene. With a higher MIC levels to tetracycline and minocyline in the tetM-positive strains than those in the tetM-negative strains, and this difference was quite significant (tetracycline: t=4.34, P =0. 0001;minocycline: t=5.90, P〈0. 0001). It is evident that tetracy-cline and minocyclie can be used as the first-line antibiotics of choice to treat the U. urealyticus infection in Jiangsu province, with a better therapeutic effect when minocycline is used. In addition, the susceptible strains of U. urealyticud to tetracyclines harbor the resistance gene term that would influence upon the elevation of the MIC levels.