酿脓链球菌对大环内酯类抗菌药物耐药表型与基因型研究

目的 研究酿脓链球菌对大环内酯类抗菌药物的耐药表型与基因型。方法 采用琼脂平板稀释法测定97株酿脓链球菌对红霉素、克林霉素、麦迪霉素、阿奇霉素、克拉霉素和青霉素的敏感性；用双纸片法检测酿脓链球菌耐药表型；用PCR方法检测耐大环内酯的酿脓链球菌携带的耐药基因。结果 97株酿脓链球菌中82株表现为对大环内酯类抗菌药物不敏感，其中42株表现为eMLS型耐药，37株为iMLS型耐药，3株细菌为主动外排M型耐药；82株对大环内酯不敏感的酿脓链球菌中77株检测到耐药基因，其中12株具有ermB基因，25株具有ermTR基因，2株具有mefA基因，21株同时具有ermB／ermTR基因，5株同时具有ermB／mefA基因，3株同时具有ermTR／mefA基因，9株同时具有ermB／ermTR／mefA基因，5株未能检测到三种耐药基因。结论 酿脓链球菌对大环内酯类抗菌药物的耐药率较高，耐药表型以cMLS和iMLS为主，耐药基因以ermB和ermTR多见。

Macrolides resistant phenotype and genotype of Streptococcus pyogenes

Objective To investigate the macrolides resistant phenotype and genotype in Streptococcus pyogenes. Methods The minimum inhibitory concentrations of erythromycin, clindamycin, midecamycin, azithromycin, clarithromycin and penicillin against 97 clinical strains of Streptococcus pyogenes were tested with agar dilution method; the macrolides resistant phenotype and genotype of Streptococcus pyogenes were detected by D-test and polymerase chain reaction. Results Eighty-two Streptococcus pyogenes were non-sensetive to at least one macrolide agent. The strains with cMLS, iMLS and M resistant phenotype were 42, 37 and 3 respectively. Seventy-seven macrolides resistant strains were detected macrolide resistant genes, which were 12 strains with ermB, 25 strains with ermTR, 2 strains with mefA, 21 strains with both ermB and ermTR, 5 strains with both ermB and mefA, 3 strains with both ermTR and mefA, 9 strains with three genes, where as resistance genes were not detected in 5 isolats. Conclusions The macrolides resistance of Streptococcus pyogenes was highly prevalence in China. The major resistant phenotypes were cMLS and iMLS. errnB and ermTR were the main resistance genes.