CAJ | 학술논문

目的了解肺炎支原体(mycoplasma pneumoniae,MP)对大环内酯类抗生素的耐药情况及耐药机制.方法对370份咽拭子标本进行MP分离培养,应用套式PCR扩增MP种特异16S核蛋白体RNA(16SrRNA)基因对临床分离株进行分子鉴定;通过药物敏感实验测定MP分离株对大环内酯类药物的MIC并筛选出耐药株;设计套式PCR扩增红霉素作用靶位23S核蛋白体RNA(23SrRNA)基因,扩增产物进行全自动DNA测序,测得序列与NCBI已登录的MP标准株M129(登录号X68422)23SrRNA基因作比对.结果 370份临床标本中分离MP 50株,分离阳性率为13.5%.50株中敏感株4株,耐药株46株(占92%).耐药菌株的红霉素、阿奇霉素、交沙霉素MIC值均升高.4株敏感株和肺炎支原体国际标准株FH的23SrRNA基因序列与基因库的MP基因序列相同,46株耐药株的23SrRNA基因发生点突变,41株突变位点在23SrRNA V区中心环的2063位,其中40株发生了A→G的点突变,1株发生了A→C的点突变;另5株突变位点在2064位,A→G.结论 MP对大环内酯类抗生素耐药率高,耐药性的分子基础是23SrRNA基因的点突变,其中2063位点突变占主导地位.23SrRNA基因发生点突变的肺炎支原体对红霉素、阿奇霉素及交沙霉素的MIC值均升高.
목적 료해폐염지원체(mycoplasma pneumoniae,MP)대대배내지류항생소적내약정황급내약궤제.방법 대370빈인식자표본진행MP분리배양,응용투식PCR확증MP충특이16S핵단백체RNA(16SrRNA)기인대림상분리주진행분자감정;통과약물민감실험측정MP분리주대대배내지류약물적MIC병사선출내약주;설계투식PCR확증홍매소작용파위23S핵단백체RNA(23SrRNA)기인,확증산물진행전자동DNA측서,측득서렬여NCBI이등록적MP표준주M129(등록호X68422)23SrRNA기인작비대.결과 370빈림상표본중분리MP 50주,분리양성솔위13.5%.50주중민감주4주,내약주46주(점92%).내약균주적홍매소、아기매소、교사매소MIC치균승고.4주민감주화폐염지원체국제표준주FH적23SrRNA기인서렬여기인고적MP기인서렬상동,46주내약주적23SrRNA기인발생점돌변,41주돌변위점재23SrRNA V구중심배적2063위,기중40주발생료A→G적점돌변,1주발생료A→C적점돌변;령5주돌변위점재2064위,A→G.결론 MP대대배내지류항생소내약솔고,내약성적분자기출시23SrRNA기인적점돌변,기중2063위점돌변점주도지위.23SrRNA기인발생점돌변적폐염지원체대홍매소、아기매소급교사매소적MIC치균승고.
Objective To investigate status of macrolide resistance and determine molecular mechanisms in Mycoplasma pneumoniae.Nethods All of 370 throat swab specimens were cultured to isolate Mycoplasma pneumoniae.Mycoplasma pneumoniae isolates were identified by nested PCR for specific 16SrRNA gene.Antibiotic susceptibility test was done to identify acrolide resistant strains.23SrRNA gene wag amplified by nested PCR followed by direct automatic sequencing method.The DNA sequences were compared to the sequence of Mycoplasma pneumoniae M129(accession no.X68422)to find molecular mechanisms of drug resistance.Results Fifty clinical strains were isolated from 370 specimens.Of 50 strains.4 strains were susceptible to macrulide,46 strains were macrolide resistant with the percentage of 92%.MICs of resistant strains to erythromycin.Azithromycin and josamycin were elevated.The sequence of 23SrRNA gene in 4 Susceptible strains and the reference strain FH was identical to Mycoplagma pneumoniae gene in GenBank.46 resistant strains arbored a point mutation respectively,among them,40 strains had all A to G transition at position 2063.1 strain had an A to C transition at position 2063,the other five strains showed an A to G transition at position 2064.Conclusions Macrolide resistance in Mycoplasma pneumoniae iS very serious health conceru.The point mutation in 23SrRNA.Xpecailly predominant position 2063 mutation contributed to the macrolide resistance in Mycoplagma pneumoniae.The MICs of resistant strains to erythromycin,azithromycin and iosamycin are much higher than Mycoplasma pneumoniae reference strain FH.