Immunity after natural exposure to enteric canine coronavirus does not provide complete protection against infection with the new pantropic CB/05 strain
Immunity after natural exposure to enteric canine coronavirus does not provide complete protection against infection with the new pantropic CB/05 strain
复制标题
DOI：
10.1016/j.vaccine.2009.10.077
复制
发表时间：
2010-01-08
期刊：
影响因子：
5.5
通讯作者：
Buonavoglia, Canio
中科院分区：
文献类型：
--
作者：
Decaro, Nicola;Elia, Gabriella;Buonavoglia, Canio
最近，已报道了由犬冠状病毒（CCoV）的泛嗜性变体（株CB/05）引起的致命感染的爆发。在本研究中，提供的证据表明，自然暴露于肠道CCoV诱导的免疫力不能完全保护菌株CB/05。将22只最近自然感染肠道CCoV的10周龄比格犬随机分为两个实验组（每组8只）（A和B组）和一个对照组（每组6只）（Q组）。A组和B组中的犬经口鼻接种不同剂量（4 × 10（5）或4 × 10（3）TCID（50））的泛嗜性菌株CB/05，而C组中的犬用作阴性对照。临床、尸检和病毒学研究表明，尽管先前自然感染肠道CCoV诱导了高血清抗体滴度，但犬对菌株CB/05的实验性感染易感。这表现为发生粪便脱落，犬表现出中度临床体征，主要是呕吐和腹泻。淋巴组织受累明显，表现为急性淋巴细胞减少症（低于初始计数的70%）、脾脏和淋巴结中的肉眼病变以及在一些感染犬的胸腺、脾脏和淋巴结中检出CB/05 RNA。仅在感染早期人道处死的犬中观察到淋巴组织中存在病毒RNA，感染的临床病程与给予的病毒剂量无关。本研究表明，CB/05株能够诱导感染和疾病的狗血清阳性肠道CCoV，从而强调需要广泛的流行病学调查和可能的新的抗原相关疫苗的开发。(C)2009爱思唯尔有限公司版权所有
Recently, an outbreak of fatal infection caused by a pantropic variant (strain CB/05) of canine coronavirus (CCoV) has been reported. In this study, evidence is provided that immunity induced by natural exposure to enteric CCoV is not fully protective against strain CB/05. Twenty-two, 10-week-old beagles with a recent natural infection by enteric CCoV were randomly distributed in two experimental groups of eight (groups A and B) and one control group of six (group Q dogs. Dogs in groups A and B were inoculated oronasally with different doses (4 x 10(5) or 4 x 10(3) TCID(50)) of the pantropic strain CB/05, whereas dogs in group C were used as negative controls. Clinical, post-mortem and virological investigations showed that, despite the high serum antibody titres induced by the prior natural infection with enteric CCoV, dogs were susceptible to experimental infection with strain CB/05. This was shown by the occurrence of faecal shedding, and dogs displaying moderate clinical signs, mainly vomiting and diarrhoea. Involvement of the lymphoid tissues was evident as demonstrated by the acute lymphopenia (below 70% of the initial counts), gross lesions in spleen and lymph nodes and detection of CB/05 RNA in thymus, spleen and lymph nodes of some infected dogs. The presence of viral RNA in lymphoid tissues was observed only in dogs euthanised in the early stages of infection and the clinical course of the infection was unrelated to the viral dose administered. The present study demonstrates that strain CB/05 is able to induce infection and disease in dogs seropositive to enteric CCoV, thus highlighting the need for extensive epidemiological investigation and for the possible development of novel antigenically relevant vaccines. (C) 2009 Elsevier Ltd All rights reserved