河流弧菌(Vibrio fluvialis)对大黄鱼(Pseudosciaena crocea)鳃粘液粘附特性研究

STUDY ON ADHESION CHARACTERISTICS OF VIBRIO FLUVIALIS TO THE GILL MUCUS OF PSEUDOSCIAENA CROCEA

采用间接ELISA法(最低检测值约104cfu)研究不同培养条件、不同培养阶段、抗体处理、营养饥饿等对河流弧菌粘附作用的影响。结果表明,经TSB培养的菌体的粘附作用极显著强于TSA培养的菌体的粘附作用(P<0.01);河流弧菌能很好地粘附于大黄鱼粘液,粘附量随菌浓度升高而增大并符合饱和粘附动力学:y=0.1782ln(x)1.6923(R2=0.9810);不同生长阶段河流弧菌的粘附能力不同,在培养初期阶段细菌的粘附量先是随着培养时间的延长而增大,并在培养24h后粘附量达到最大,而后随着培养时间的延长其粘附量急剧下降;抗体处理后河流弧菌的粘附量显著低于对照组(P<0.05);营养饥饿菌体的粘附量明显降低。以上结果表明:海水中的河流弧菌能很好地粘附于大黄鱼鳃粘液,其粘附作用受细菌培养条件、营养状况等自身因素的显著影响。本研究结果有助于了解河流弧菌的流行病学和致病机理。

In order to get a better understanding of adhesion of pathogenic Vibrio fluvialis to the gill mucus of Pseudo- sciaena crocea, the influences of culture condition, bacterial density, culture stage, antibody treatment on the bacterial adhesion were investigated by indirect ELISA, successfully established by modifying various conditions. The results showed that the adhesion ability of Efluvialis incubated in TSB was extremely stronger than that of Efluvialis incubated in TSA （P〈0.01）; the adhesive quantity of V. fluvialis increased with bacterial densities and peaked at 180 min post-incubation under 25 ℃; a saturation kinetics hyperbola： y = 0.17821n（x）-1.6921 （R2 = 0.9810）, was obtained by plot- ting adhered bacteria against the density of bacteria added; different adhesion abilities were showed when V. fluvialis at different culture stages. During 0 to 24 hour, the number of adhering bacteria increased with incubation time and reached peak at 24h, and then dropped sharply with the culture time extension. After the bacteria were treated with rabbit antiserum against O-antigen of V. fluvialis, the number of adhering bacteria reduced by 52%. All the results indicate that V. fluvialis can adhere to the skin mucus of P croeea strongly in seawater by specific adhesion. However this kind of bacterial adhesion was not only remarkably influenced by environmental factors but also by culture conditions and nutrition level. These results are helpful for better understanding the characteristics of epidemiology and pathogenesis of V. fluvialis, which might be useful for the vibriosis control in fish culture.