摘要
目的 探讨 gyrA基因在人型支原体 (Mh)耐喹诺酮类药物中的突变作用。方法 从 100株取自临床的 Mh中，通过肉汤稀释法筛选出 3株对 9种喹诺酮类药物呈交叉耐药的 Mh株，进行 gyrA基因的 PCR扩增，分析产物的核苷酸序列，与标准敏感株 MhPG21的 gyrA基因进行比较。结果 3株 Mh的 gyrA基因 PCR扩增均得到一 350 bp的阳性片段，产物核苷酸序列分析发现 3株均有 113位 C→ T、 168位 T→ A、 183位 C→ T、 261位 T→ C的突变，其中 113位 C→ T的突变导致其编码的 83位丝氨酸转变为亮氨酸，其它突变未改变其编码的氨基酸。 结论 gyrA基因中 C→ T的突变与 Mh耐喹诺酮类药物密切相关。
Objective To study the role of gyrA gene in quinolone resistant mutants of Mycoplasma hominis(Mh). Methods Three cross resistant mutants of Mycoplasma hominis(Mh) to 9 quinolones were selected from 100 clinical strains of Mh by broth dilution method. Their gyrA were amplified by PCR, and the nucleotide sequences were compared to those of susceptible strain MhPG21 by DNA sequencing. Results A 350 bp DNA fragment was obtained by PCR. Three resistant mutants contained nucleotide 113 C→ T， 168 T→ A， 183 C→ T， 261 T→ C transitions. Only 113 C→ T transition lead to substitution of Ser－ 83 by Leu in the gyrA protein, the others did not lead to the substitution of amino acid. Conclusion These results suggest that a gyrA mutation in Mh at Ser－ 83 is associated with quinolone resistance.
出处
《中华皮肤科杂志》
CAS
CSCD
北大核心
2000年第3期169-170,共2页
Chinese Journal of Dermatology
基金
湖南省教委资助重点课题
