医用导管内鲍氏不动杆菌生物膜与ICU医院感染相关性研究

Correlative Research on Biofilm Formed by Acinetobacter baumannii in Medical Catheter with Nosocomial Infection in ICU

目的探讨临床标本中鲍氏不动杆菌形成生物膜的状况,研究游离态的鲍氏不动杆菌与生物膜中的鲍氏不动杆菌对医院感染的区别,以及时有效控制鲍氏不动杆菌医院感染。方法对临床标本分离的鲍氏不动杆菌进行鉴定,采用刚果红培养基筛选鲍氏不动杆菌生物膜的模式菌株,并用阿利新蓝水溶液与刚果红联合对细菌胞外多糖染色观察该菌生物膜的形成情况,微量平板法定量检测生物膜形成,扫描电镜观察导管材料表面形成生物膜的表面结构。结果刚果红法检测能够形成生物膜的鲍氏不动杆菌的模式菌株阳性率51.39%;阿利新蓝-刚果红染色鲍氏不动杆菌胞外多糖呈深红色,背景呈深蓝色;生物膜半定量法显示菌液浓度与生物膜的形成有关。结论阿利新蓝染色法可用于鲍氏不动杆菌胞生物膜中的多糖染色,结晶紫染色法可用于生物膜的定量检测,鲍氏不动杆菌生物膜的形成与ICU医院感染有关系。

OBJECTIVE To investigate the condition of biofilm formed by Acinetobacter baumannii and study the differences in hospital infection between free state A.baumannii and A.baumannii in biofilm.In this way the nosocomial infection of A.baumannii may be controlled promptly and effectively.METHODS A.baumannii isolated from clinic were identified and screened for model strains which could form biofilm on Congo Red medium.The formed condition of biofilm was observed by staining of exopolysaccharide with Alcian Blue aqueous solution and Congo Red.The biofilm formation was detected quantitatively with micro-plate method,and the surface structure of biofilm grown on catheter material was observed by scanning electron microscope.RESULTS The positive rates of biofilm producing strains which could form the biofilm was 51.39% with Congo Red method.After staining with Alcian Blue and Congo Red,the exopolysaccharide of A.baumannii appeared dark red,while the background appeared dark blue.The detection with biofilm semiquantitative method showed that the concentration of bacteria liquid was related with the biofilm formation.CONCLUSION The staining method with Alcian Blue can be used in the staining of biofilm exopolysaccharide and the staining method with Crystal Violet can be used in the quantitative detection of biofilm.The biofilm formation of A.baumannii is related to the nosocomial infection in ICU.