摘要目的 研究中国2006年耐甲氧西林金黄色葡萄球菌(MRSA)流行株的来源和遗传背景.方法 收集2006年1-12月15个地区17家医院连续分离的非重复MRSA 302株,通过多重PCR对MRSA进行染色体mec(SCCmec)分型,葡萄球菌A蛋白(Spa)分型和多位点序列分型(MLST).结果 SCCmec分型Ⅲ型为76.8%,不能分型为7.9%.从广州地区分离株中发现2株Ⅳ型,Ⅱ型为14.6%;而大连地区分离株中Ⅱ型为75.0%,与其他地区菌株分型的差异存在统计学意义(P<0.005).MLST共有4种分型,其中序列分型(ST)239(46.7%)、ST5(44.4%)、ST59(6.7%)、ST88(2.2%).Spa分型共有14种,其中t30(52.6%)、t37(27.2%)、t2(12.9%)、t632(2.3%)、t437(1.3%)和t570、t601(各0.7%)及t377、t459、t796、t899、t1152、t2649(各0.3%),未分型占0.3%.未检出pvl以基因.结论 调查的15个地区MRSA主要克隆株为ST239-MRSA-SCCmecⅢ-t30和ST5-MRSA-SCCmecⅡ-t2,具有独特的地理分布.

abstractsObjective To investigate the source and genetic background of methicillin-resistant Staphylococcus aureus in the year of 2006,in China. Methods From January to December 2006,a total number of 302 consecutive and non-repetitive methicillin-resistant Staphylococcus aureus were collected from 17 Teaching hospitals in 15 areas. Genotypes of SCCmec were determined by multiplex PCR and multilocus sequence typing (MLST) was used to type the house-keeping genes. The implementation of the spa typing method was straightforward,and the results obtained were reproducible,unambiguous,and easily interpreted. Results All areas but Dalian harbored SCCmec Ⅲ while Dalian harbored SCCmec Ⅱ most. There were two strains in Guangzhou,harboring SCCmec Ⅳ. There were four strains of sequence type(ST),with ST239 accounted for 46.7% and ST5 accounted for 44.4%. ST59 accounted for 6.7% and ST88 accounted for 2.2%. There were fourteen strains of Spa typing,with t30 accounted for 52.6% ; t37 accounted for 27.2% ; t2 accounted for 12.9% ; t632 accounted for 2.3% ; t437 accounted for 1.3% ; t570,t601 accounted for 0.7% ; t377,t459,t796,t899,t1152,t2649 accounted for 0.3% ; no-typing accounted for 0.3%,respectively,pvl gene was not detected. Conclusion The main clone strains were ST239-MRSA-SCCmec Ⅲ-t30,ST5-MRSA-SCCmec Ⅱ-t2,with unique geographic distributions across the whole nation.