科氏葡萄球菌解脲亚种的溶血性和耐药性及同源性研究

Investigation on hemolysis,resistance and homology of Staphylococcus cohnii urealyticum

目的了解科氏葡萄球菌解脲亚种的溶血性、耐药性及同源性。方法对13株科氏葡萄球菌解脲亚种进行回顾性研究。经质谱仪再鉴定后观察菌株在血平板上的溶血特性,测定菌株与金黄色葡萄球菌的协同溶血情况;聚合酶链反应检测溶血素基因和耐药基因;脉冲场凝胶电泳技术及质谱技术进行同源性分析;琼脂稀释法测定菌株对常用抗菌药物的敏感性。结果明确鉴定的13株科氏葡萄球菌解脲亚种表现出不同程度的溶血,金黄色葡萄球菌具有促进溶血作用。13株菌对万古霉素和替加环素敏感,携带mecA基因、cfr基因和ermC基因的菌株数分别为12、7和7。质谱仪聚类分析可将13株菌分为3个组,脉冲场凝胶电泳技术将其分为6个分子型别。结论科氏葡萄球菌解脲亚种不同菌株的溶血作用存在差异,金黄色葡萄球菌能促进其溶血作用。尽管科氏葡萄球菌解脲亚种携带多种耐药基因,但都对万古霉素和替加环素敏感。

Objective To investigate the characteristics of hemolysis,resistance and homology of Staphylococcus cohnii urealyticum.Methods A retrospective study was carried out on thirteen clinical strains of Staphylococcus cohnii urealyticum.They were re-identified by MALDI-TOF MS.Their colony and hemolytic characteristics on blood agar plates were observed.The co-hemolysis between Staphylococcus cohnii urealyticum and Staphylococcus aureus was demonstrated.The hemolysin genes and drug resistance genes were detected by PCR.Pulsed field gel electrophoresis and mass spectrometry were used to analyze the homology of strains.The susceptibility of strains to antimicrobial agents was detected by agar dilution.Results The confirmed 13 strains of Staphylococcus cohnii urealyticum showed various levels of hemolysis and had enhanced synergistic hemolysis with Staphylococcus aureus.All strains were susceptible to vancomycin and tigecycline.There were 12 strains which carried mecA gene,7 strains carried cfr gene,7 strains carried ermC gene.The 13 strains were divided into 3 groups by MALDI-TOF MS,and 6 types by pulsed field gel electrophoresis.Conclusions Clinical strains of Staphylococcus cohnii urealyticum demonstrated various levels of hemolysis which could be enhanced by Staphylococcus aureus.Although they carried different drug resistance genes,they were all susceptible to vancomycin and tigecycline.