CAJ | 학술논문

目的：探讨 psm-mec 基因在临床分离表皮葡萄球菌中的分布和表达,为进一步分析 psm-mec 的功能奠定基础。方法收集临床分离并经过全自动微生物鉴定系统准确鉴定的表皮葡萄球菌165株,通过 PCR 扩增esp 和mecA 基因准确鉴定和区分甲氧西林敏感表皮葡萄球菌(MSSE)和甲氧西林耐药表皮葡萄球菌(MRSE)。扩增 psm-mec 、fudoh 和 p221片段确认 psm-mec 携带菌株,通过 DNA 序列比对分析 psm-mec 及其上游序列的变化。构建 p221重组质粒制备定量检测 psm-mec 的标准品,提取携带 psm-mec MRSE 总 RNA,采用荧光定量 RT-PCR分析临床分离 MRSE psm-mec 转录水平。结果83.64%的临床分离表皮葡萄球菌为 MRSE,其中29株携带 psm-mec 基因,携带率为17.58%,且仅分布于 MRSE 中。所有菌株 psm-mec 开放读码框序列无突变,仅4.34%菌株在psm-mec 基因上游存在 G>A 的点突变。临床分离携带 psm-mec 菌株均表达此基因,其表达水平在103~107拷贝之间,G>A 点突变不影响 psm-mec 转录表达。结论psm-mec 仅分布和表达于临床分离 MRSE 中,G>A 点突变不影响 psm-mec 表达。
목적：탐토 psm-mec 기인재림상분리표피포도구균중적분포화표체,위진일보분석 psm-mec 적공능전정기출。방법수집림상분리병경과전자동미생물감정계통준학감정적표피포도구균165주,통과 PCR 확증esp 화mecA 기인준학감정화구분갑양서림민감표피포도구균(MSSE)화갑양서림내약표피포도구균(MRSE)。확증 psm-mec 、fudoh 화 p221편단학인 psm-mec 휴대균주,통과 DNA 서렬비대분석 psm-mec 급기상유서렬적변화。구건 p221중조질립제비정량검측 psm-mec 적표준품,제취휴대 psm-mec MRSE 총 RNA,채용형광정량 RT-PCR분석림상분리 MRSE psm-mec 전록수평。결과83.64%적림상분리표피포도구균위 MRSE,기중29주휴대 psm-mec 기인,휴대솔위17.58%,차부분포우 MRSE 중。소유균주 psm-mec 개방독마광서렬무돌변,부4.34%균주재psm-mec 기인상유존재 G>A 적점돌변。림상분리휴대 psm-mec 균주균표체차기인,기표체수평재103~107고패지간,G>A 점돌변불영향 psm-mec 전록표체。결론psm-mec 부분포화표체우림상분리 MRSE 중,G>A 점돌변불영향 psm-mec 표체。
Objective To explore the distribution and expression of psm-mec in clinical isolates of Staphylococcus epidermidis and to provide foundation for its function analysis. Methods 1 65 strains of S .epidermidis identified accurately by full automation microbiological identification system were collected,and PCR was used to amplify esp and mecA gene to differentiate methicillin-resistant S .epidermidis (MRSE)and methicillin-sensitive S .epidermidis (MSSE).Strains with psm-mec were validated by amplification of psm-mec , fudoh and p221 fragments,and DNA sequence analysis was performed to determine mutation in psm-mec and its upstream sequences.psm-mec reference standard was obtained by construction of p221 recombinant plasmid.RNA of MRSE with psm-mec was extracted,and its mRNA level was measured by fluorescent quantitative RT-PCR. Results MRSE accounted for 83.64% of clinical isolated S .epidermidis ,and 29 strains were positive to psm-mec with a rate of 1 7.58%,which distributed only in MRSE.No mutation was observed in psm-mec ORF sequence,but a G to A point mutation of psm-mec in 4.34% strains.psm-mec expressed with a level ranging from 10 3 to 10 7 copies in all clinical isolates of MRSE with psm-mec ,and the G to A point mutation did not affect psm-mec transcription.Conclusion psm-mec distributes and expresses only in clinical isolates of MRSE,and G>A mutation of psm-mec has no effect on its expression.