金黄色葡萄球菌生物膜产生及相关毒力因子研究

目的 金黄色葡萄球菌引起的感染遍及临床各科,人体各部位。对临床分离的金黄色葡萄球菌进行生物膜、生物膜相关因子及毒力因子检测；方法 刚果红培养基法进行生物膜筛选；用电子显微镜观察生物膜的形成；用PCR方法检测生物膜相关基因及毒力因子。结果 100株金黄色葡萄球菌中,63株产生生物膜,产生物膜率达63.0％,均产生与生物膜高度相关的icaA基因、icaD基因；还可产生ebh、sea、seb、pvl、hla、fnbA 等毒力因子；产生物膜的菌中MRSA菌株占51.2%,MSSA占48.8%；结论 产生物膜的金黄色葡萄球菌已经成为医院感染的致病因素之一,常产生各种毒力因子。

Detection of biofilm formation and biofilm associated genes of S.aureus clinical isolation

Objective The infection caused by Staphylococcus aureus has become an issue throughout clinical departments and various parts of the human body and it has become a pathogen of nosocomial infection such as bloodstream infection and endocarditis etc. To detect biofilm formation and biofilm associated genes of S.aureus clinical isolation. Methods: Biofilm were screened in the Congo red medium method, and quantitative detection was performed using the crystal violet method. The biofilm formation screening was determined by Congo Red Agar semi quantitative microplate assay and scanning electron microscopy method, and both ica and sarA genes were detected by PCR in 62 strains of S.aureus clinical isolation. Results: All of 62 strains in this study could form biofilm, and carry the icaA and icaB gene; The resistance of biofilm positive strains to ciprofloxacin, levofloxacin, rifampicin and gentamicin was significantly higher than that of biofilm negative strains. The MRSA positive rate of biofilm positive bacteria was up to 66.7%, which was significantly higher than that of biofilm negative strains. No vancomycin, linezolid and teicoplanin resistant strains were found between biofilm positive and negative strains. Conclusion: The S.aureus clinical isolations had the ability of biofilm formation, and the gene of ica and sarA were prevalent in S.aureus. Staphylococcus aureus is associated to biofilm often produces virulence factors. Biofilm has become a key role in nosocomial infection .