超声探头表皮葡萄球菌分子流行病学同源性研究

Homology research of staphylococcus epidermidis molecular epidemiology by ultrasound probes

目的对表皮葡萄球菌进行分子流行病学研究和同源性分析,探讨超声探头的传染源及传播方式。方法收集不同时间、不同来源的表皮葡萄球菌菌株30株,随机抽取10株进行分子流行病学同源性研究。10株表皮葡萄球菌分别来自超声探头(3株)、普通感染病例(2株)、医院感染病例(2株)和超声检查前后病人的皮肤(3株)。对上述菌株进行药物敏感试验、脉冲场凝胶电泳(PFGE)分析,以了解各菌株间的亲缘关系。结果 PFGE分析结果显示:由检查前超声探头上分离的406号表皮葡萄球菌株与超声检查后病人皮肤上分离的408号表皮葡萄球菌株图谱一致,表现为DNA片段大小一致和数量相同的电泳图谱,从基因上具有高度同源性,为流行病学相关带型大小和数量相近的菌株。除上述2株外,其他各个菌株相互之间条带差异都在3条或3条以上,不来源于同一个克隆,这些菌株存在多种污染来源。结论病原微生物可通过超声探头媒介而传播到被检查者的皮肤。超声探头是医院感染的一种传播方式,故严格执行消毒隔离技术,实行探头在接触患者前后消毒等常规措施对减少医院感染有重要意义。

Objective To explore the source of infection and mode of transmission on the uhrasonic probe by studying the molecular epidemiology and the homology analysis of staphylococcus epidermidis. Methods Thirty Staphylococcus epidermidis strains from different times and different sources, Then 10 strains were randomly selected for homologous studies of molecular epidemiology, including 3 strains of ultrasound probe, 2 strains of general infections, 2 strains of hospital infections and 3 strains of patient ＂s skin before and after ultrasound examination. Then the drug sensitivity test and pulse field gel electrophoresis （PFGE） analysis were performed on these strains to understand the genetic relationship between each of them. Results The PFGE analysis showed that NO. 406 strain of staphylococcus epidermidis separated from ultrasonic probe before the examination had the same map of staphylococcus epidermidis strains with NO. 408 strain which separated from the patient after the ultrasound examination, it showed the same DNA fragment size and the same number of SDS-PAGE bands. From the gene which had a high degree of homology, they were the strains with similar banding pattern and number. Except these two, the difference of the bands between the other various strains were three or more than three , so they should not be derived from the same clone that is not in the epidemiological correlation, indicating the existence of these strains had a variety sources of pollution. Conclusion Pathogenic microorganism can transmits to patients＇ skin by ultrasonic probe, and ultrasonic probe is also a mode of transmission of hospital infection, so it is important to reduce hospital infection with strict aseptic operation, implementation of disinfection before and after contacting with patients and other routine measures.