causative agent

Haemophilus parasuis is a causative agent of swine polyserositis, polyarthritis and meningitis.

副猪嗜血杆菌（Haemophilus parasuis，HPS）能引起猪的多发性浆炎、关节炎炎，随着世界养猪业的发展，该病已成为全球范围内影响养猪业的种重细菌学疾病。

An investigation of Anisakis simplex larvae,the most important causative agent of anisakiasis,in marine fishes caught in Bohai sea was carried out in order to detect their infectivity.

为了了解渤海各种鱼类中人体异尖线虫病的病源——简单异尖线虫幼虫的感染情况,进行本调查。