格氏乳球菌分离株的血清同源性及血清学检验

Examination of serum homology and serology of Lactococcus garvieae

以分离于病(死)牙鲆(Paralichthys olivaceus L.)的格氏乳球菌(Lactococcus garvieae)的代表菌株(T030817-1株),分别制备全菌(OK)及热处理(121℃作用1h)菌体(O)免疫原,强化免疫接种家兔制备相应抗血清,对10株格氏乳球菌分离株进行了血清同源性检验。结果表明,供试10株菌均存在同种的表面K抗原和同种的菌体O抗原(血清同源),其中O抗原具有强免疫原性、K抗原免疫原性及O凝集抑制阻断作用弱;以相应OK抗血清为第1抗体、标准的羊抗兔IgG荧光抗体为第2抗体,对10株格氏乳球菌的纯培养物及用代表菌株(T030817-1)人工感染病死牙鲆的肝组织进行了间接荧光抗体染色,结果显示了特异的荧光反应;同时,对从人工感染死亡牙鲆分离的6株纯培养菌以凝集试验进行了检验,亦显示特异凝集反应。

Whole cells （OK） antigens and the correspondent ＂O＂ antigens obtained by heating the bacterial suspensions at 121 ℃ for 1 h were prepared with representative strain （T030817-1） of Lactococcus garvieae isolated from moribund （dead） Paralichthys olivaceus L. The antigens were inoculated to rabbit for preparation of antiserum. Then serum homology of 10 strains was checked by using the antiserum. The results showed that there existed the same K-antigen and the same O-antigen （the same originating serum） in all of the 10 strains. The O-antigen has strong immunogenicity, while the K-antigen has weak immunogenicity and definite agglutination inhibiting effect on O-antigen. By using the corresponding OK antiserum as the first antibody and the standard goat anti rabbit IgG-FITC （fruorescein isothiocyanate, FITC） as the second antibody, the fluorescent antibody staining was conducted on the pure cultures of 10 strains of Lactococcus garvieae and liver tissues isolated from moribund flounder infected with representative strain （T030817-1）. The results showed that all examined strains displayed special fluorescent reaction. In addition, 6 pure cultures isolated from dead fish dead infected artificially were inspected through agglutination test, special agglutinative reaction appeared also.