Addie D D, Schaap I A T, Nicolson L, Jarrett O
Department of Veterinary Pathology, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK.
J Gen Virol. 2003 Oct;84(Pt 10):2735-2744. doi: 10.1099/vir.0.19129-0.
To examine the mode of natural transmission and persistence of feline coronavirus (FCoV), FCoV strains shed by domestic cats were investigated over periods of up to 7 years. An RT-PCR that amplified part of the 3' end of the viral spike (S) gene was devised to distinguish FCoV types I and II. All but 1 of 28 strains of FCoV from 43 cats were type I. Nucleotide identities of the amplified 320 bp product from 49 type I FCoVs ranged from 79 to 100 %. The consensus partial S sequence of isolates recovered from persistently infected cats at time intervals spanning years was generally conserved. While most cats were infected with a single strain, a few may have been infected by more than one strain. Cats that were transiently infected and ceased shedding could be re-infected with either the same, or a different, strain. In most cases, whether a cat became persistently or transiently infected was independent of the virus strain. However, one strain was unusual in that it infected the majority of cats in the household simultaneously and was still being shed 18 months later. Factors that influence whether FCoV establishes lifelong infection in some cats and not others are determined mainly by the host response to infection.
为了研究猫冠状病毒（FCoV）的自然传播方式和持续性，对家猫排出的FCoV毒株进行了长达7年的调查。设计了一种逆转录聚合酶链反应（RT-PCR），用于扩增病毒刺突（S）基因3'端的部分序列，以区分I型和II型FCoV。来自43只猫的28株FCoV中，除1株外均为I型。49株I型FCoV扩增得到的320 bp产物的核苷酸同一性范围为79%至100%。从持续感染的猫中，在跨越数年的时间间隔内回收的分离株的共有部分S序列通常是保守的。虽然大多数猫感染的是单一毒株，但少数猫可能感染了不止一种毒株。短暂感染并停止排毒的猫可能会再次感染相同或不同的毒株。在大多数情况下，猫是持续感染还是短暂感染与病毒毒株无关。然而，有一个毒株不同寻常，它同时感染了家中的大多数猫，并且在18个月后仍在排毒。影响FCoV在某些猫而非其他猫中建立终身感染的因素主要由宿主对感染的反应决定。
