肺炎支原体耐大环内酯类抗菌药物分子机制的初步研究

Molecular Mechanisms of Macrolide Resistance of Mycoplasma pneumoniae

目的了解肺炎支原体(MP)耐大环内酯类抗菌药物情况及主要的耐药机制。方法从32例因MP引起呼吸道感染的患儿取咽拭子,采用改良Hayflick培养基分离培养;运用药物敏感试验筛选耐大环内酯类抗菌药物的耐药株;聚合酶链反应(PCR)扩增结合序列测定分析耐药分子机制。结果32份标本培养成功19份;药敏结果显示19株MP临床分离株中有15株耐药,占78.9%,而且一旦对其中1种药物耐药,对其他大环内酯类抗菌药物也均呈耐药性;敏感株和标准株FH的测序结果完全相同,15株耐药株23SrRNAⅤ区均出现了A2063G的点突变,其中有2株为敏感株和耐药株共生。结论MP对大环内酯类抗菌药物耐药现状严重,其主要的耐药机制为23S rRNAⅤ区产生点突变。

OBJECTIVE To investigate macrolide resistance and main molecular mechanisms in Mycoplasma pneurnoniae. METHODS Thirty two throat swabs from children infected with M. pneumoniae were cultured by modified Hayflick medium. Antibiotic susceptibility test was used to screen the maerolide-resistant M. pneumoniae. The 23S rRNA gene sequences of the strains were determined with polymerase chain reaction and sequencing. RESULTS Nineteen strains were isolated from 32 throat swabs successfully. Fifteen strains were resistant to macrolide antibiotics according to the results of antibiotic susceptibility test. Once the strain was resistant to one of macrolide antibiotics, it would be resistant to the others. Sequencing results of the sensitive strains and the standard strain FH were completely same. Fifteen resistant strains presented A2063G point mutation in 23 SrRNA region V, in which 2 examples showed the coexistence of the sensitive strain and the resistant strain. CONCLUSIONS Macrolide-resistant M. pneumoniae is common and serious at present. The antibiotic resistant isolate carries point mutations of the 23S rRNA region V.