携带新SCCmec型别菌株的耐药特点及PCR图谱多位点序列分析

Multilocus sequence analysis on polymerase chain reaction map and antimicrobial resistance of isolates with new staphylococcal cassette chromosome mec

目的了解前期研究中发现的3株携带有新型SCCmec聚合酶链反应(PCR)谱型的耐甲氧西林金黄色葡萄球菌(MRSA)的位点序列特性。方法在前期的分型研究中,从58株MRSA中检测到3株(5.17%)携带了一种新的SCCmec多位点PCR谱型,其含有5条扩增带,依次为A、F、H、B和M。对上述扩增产物测序,用BLAST与国际基因库内已知位点序列进行对比分析。结果测得序列与已有位点相应序列的同源性均在97%以上。结论此型为一新的SCCmec多位点PCR谱型,是传统Ⅰ、Ⅱ和Ⅲ型的重组型,与已有型别比较,不但有不同的位点图谱,且有多个点突变。

Objective To study the multilocus sequence characteristics of polymerase chain reaction （PCR） map of 3 isolates of methicillin-resistant Staphylococcus aureus （MRSA） which carried a new staphylococcal cassette chro- mosome rnec（SCCmec） . Methods In the previous PCR typing study on 58 MRSA isolates, 3 （5. 17%） were found to carry a new SCCmec multilocus sequence containing 5 bands, which were band A, F, H, B and M. The above am- plified products were sequenced, and then compared with the sequences of SCCmec type saved in the international GenBank and the Basic Local Alignment and Search Tool （BLAST）. Results The homology between the detected sequence and the known sequence was over 97 % Conclusion It＇ s a new PCR pattern of multilocus sequence of SCCmec type, and maybe the recombinant of conventional SCCmec type Ⅰ, Ⅱ andⅢ, which is not only a different PCR pattern, but also has multilocus mutation.