Fang Sufang, Meng Linghai, Shi Yubo, Hao Chengyu, Gu Xiaolong, Du Fangchen, Cui Ping, Tang Xinming
College of Animal Science and Technology, Hebei North University, Zhangjiakou 075000, China.
Key Laboratory of Animal Biosafety Risk Prevention and Control (North), Key Laboratory of Veterinary Biological Products and Chemical Drugs of MARA, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Animals (Basel). 2024 Dec 5;14(23):3524. doi: 10.3390/ani14233524.
Coccidiosis is one of the most significant diseases affecting the rabbit industry and is caused by . In a previous study, we identified a new species of (-ZJK) from the northern region of China (Zhangjiakou, Hebei Province) and studied its pathogenicity and immunogenicity. The aim of this study was to evaluate the pathogenicity, immunogenicity, and cross-immunogenicity from different geographical isolates of for vaccine development. Two geographical isolates of -QD from Qingdao, Shandong Province (eastern China), and CD from Chengdu, Sichuan Province (southwestern China), were isolated and identified. The pathogenicity, immunogenicity, and cross-immunogenicity among the three geographical isolates were evaluated. The pathogenicity results showed that after infecting rabbits with doses of 1 × 10 or fewer sporulated oocysts of -QD and -CD, the rabbits exhibited clinical symptoms but recovered quickly, indicating lower pathogenicity. Immunogenicity studies revealed that after immunizing rabbits with 1 × 10 sporulated oocysts of -QD and -CD for 14 days, followed by challenge with 1 × 10 homologous sporulated oocysts, the oocyst reduction rates in the immunized groups were 99.39% and 99.12%, respectively, compared with the non-immunized groups, demonstrating good immunogenicity. In cross-immunogenicity studies, rabbits were immunized with 1 × 10 sporulated oocysts of -ZJK, -QD, or -CD and then challenged with 1 × 10 sporulated oocysts of heterologous isolate. The immunized groups showed no significant clinical symptoms, and the oocyst reduction rates ranged from 55.9% to 98.4%. -CD exhibited cross-protection against -ZJK and -QD, making it an ideal candidate formulation for vaccine development.
球虫病是影响养兔业的最重要疾病之一，由……引起。在先前的一项研究中，我们从中国北方地区（河北省张家口市）鉴定出一种新的……（-ZJK）物种，并研究了其致病性和免疫原性。本研究的目的是评估来自不同地理分离株的……的致病性、免疫原性和交叉免疫原性，以用于疫苗开发。分离并鉴定了来自中国东部山东省青岛市的-QD和来自中国西南部四川省成都市的CD这两个地理分离株。评估了这三个地理分离株之间的致病性、免疫原性和交叉免疫原性。致病性结果表明，用-QD和-CD的1×10个或更少的孢子化卵囊感染兔子后，兔子出现临床症状但恢复迅速，表明致病性较低。免疫原性研究显示，用-QD和-CD的1×10个孢子化卵囊免疫兔子14天后，再用1×10个同源孢子化卵囊进行攻毒，与未免疫组相比，免疫组的卵囊减少率分别为99.39%和99.12%，表明具有良好的免疫原性。在交叉免疫原性研究中，用-ZJK、-QD或-CD的1×10个孢子化卵囊免疫兔子，然后用异源分离株的1×10个孢子化卵囊进行攻毒。免疫组未出现明显临床症状，卵囊减少率在从55.9%到98.4%之间。-CD对-ZJK和-QD表现出交叉保护作用，使其成为疫苗开发的理想候选制剂。
