嗜水气单胞菌细胞提取物特性的分析

对六株嗜水气单胞菌的全细胞和外膜成份在不同的培养条件下进行SDS-PAGE、免疫转印分析.在同一培养条件下6个供试菌株全细胞的蛋白质电泳图谱不同.同一菌株在五种不同的培养条件下,其蛋白质电泳图谱相似但有差异.6株菌株的细菌外膜提取物的蛋白质电泳图谱不同,同一菌株在5种不同的培养条件下,其蛋白质电泳图谱相似但有差异,但所有的图谱均具有34 kDa和30 kDa的条带.用Schiff's试剂,银染及生物素标记(BS-1,ConA,UEA-1)法测定及分析提取物中糖或碳水化合物的特征.生物素标记及经蛋白酶K处理后的所有菌株的提取物均显示不同分子量碳水化合物的条带,但具有相同分子量的条带,其中32 kDa条带被三种生物素及银染所显示,而34 kDa仅被生物素BS-1和UEA-1所识别.经Schiff's试剂染色后,仅出现少量的条带.用免疫转印法测定菌体提取物的抗原性,结果显示,提取物有多条不同的条带被两种血清所识别,且用活菌制备的血清比死菌的要强得多.所有菌株在不同培养条件下的提取物均具35 kDa条带被鱼血清所识别.所以,35 kDa条带可能是嗜水气单胞菌的共同抗原.同时,用ELISA法测定,证明鱼血清与其它菌株间有较强的交叉反应.

Characterization of Extract of Aeromonas hydrophila

Whole cell(WC) and extract from six virulent strains of Aeromonas hydrophila were characterized by SDS-PAGE and Western blot analysis.The protein profiles of WC and extract indicated that all the isolates on different conditions had various bands but had the same molecular weight bands.The same isolate on five conditions had the similar bands pattern.Schiff's reagent,Silver stain and Lectin staining(BS-1,ConA,UEA-1) were used to examine and characterize carbohydrate presented in the extract.The lectin staining and silver stain(proteinase K treated extract) showed all the isolates which produced bands representing carbohydrates of different molecular weights,the 32 kDa band being recognized by three lectins and silver stain,34 kDa band by lectin BS-1 and UEA-1.The gels were also stained by Schiff's reagent,but only few bands appeared.Tilapia anti-A.hydrophila sera against live and killed T_4 were prepared to determine the antigenicity of extract by Western blot analysis.The results indicated that various bands of extract of A.hydrophila could be recognized by both fish sera.However,the reaction of serum against the live bacteria was stronger than that against the killed.It appeared that all the isolates expressed a 35 kDa band when the extract was performed on any one of the five mediums,which was reacted with fish antibody.This showed that the 35kDa band may be a common antigen in all these 6 bacterial pathogens and suggests that the 35 kDa band may represent a protein.The antibody titer and cross-reaction of fish serum were confirmed by ELISA test.