Bianchi T I, Avilés G, Sabattini M S
Servicio Nacional de Sanidad Animal, Relaciones Internacionales, Buenos Aires, Agentina.
Acta Virol. 1997 Feb;41(1):13-20.
In order to expand our knowledge on the biological characteristics of an enzootic South American subtype of western equine encephalomyelitis (WEE) virus, strain AG80-646, we inoculated guinea pigs, rabbits, newborn chickens and Vero and chick embryo cell cultures with this and other WEE and Wee-related viruses. AG80-646 was found apathogenic for guinea pigs even when inoculated intracranially (i.e.) or intraperitoneally (i.p.), and the animals did not develop viraemia. AG80-646 killed rabbits and the animals developed high viraemia (peak titer was 7.0 log PFU/0.1 ml). These data and previous serological evidence led us to look for a mammal as a natural host. AG80-646 was found lethal for newborn chickens inoculated subcutaneously (s.c.) (peak viraemia titer was 6.6 log PFU/0.1 ml). AG80-646 produced plaques (diameter 0.8-1.0 mm) in Vero and chick embryo cells 3-4 days post infection (p.i.) A comparison of AG80-646 with other WEE complex virus strains led to the following observations: (1) The lethality for guinea pigs was high for the two epizootic Argentinian strains, Cba 87 and Cba CIV 180, zero for the two enzootic strains, AG80-646 and BeAr 10315 (virus Aura), and intermediate for the Russian strain Y62-33 (low by i.c. route and zero by i.p. route); (2) AG80-646 was more virulent for rabbits inoculated i.p. than the three epizootic strains Cba 87, Cba CIV 180 and McMillan; (3) AG80-646 was less virulent for new-born chickens than the Argentinian epizootic strain Cba CIV 180; (4) The viraemia level correlated always with the strain virulence in each animal host. This study provides tools for the differentiation of WEE complex viruses and strains in the future ecological work on WEE in South America.
为了拓展我们对一种南美洲地方流行性西部马脑炎（WEE）病毒AG80 - 646株生物学特性的认识，我们用该病毒以及其他WEE病毒和与WEE相关的病毒接种豚鼠、兔子、新生鸡以及Vero细胞和鸡胚细胞培养物。结果发现，即使经颅内（即i.c.）或腹腔内（i.p.）接种，AG80 - 646对豚鼠无致病性，且这些动物未出现病毒血症。AG80 - 646可致兔子死亡，且这些动物出现了高病毒血症（峰值滴度为7.0 log PFU/0.1 ml）。这些数据以及先前的血清学证据促使我们寻找一种哺乳动物作为其自然宿主。结果发现，AG80 - 646对皮下（s.c.）接种的新生鸡具有致死性（峰值病毒血症滴度为6.6 log PFU/0.1 ml）。感染后3 - 4天，AG80 - 646在Vero细胞和鸡胚细胞中产生了噬斑（直径0.8 - 1.0 mm）。将AG80 - 646与其他WEE复合病毒株进行比较后得出以下观察结果：（1）两种阿根廷流行株Cba 87和Cba CIV 180对豚鼠的致死率较高，两种地方流行株AG80 - 646和BeAr 10315（奥拉病毒）对豚鼠的致死率为零，俄罗斯株Y62 - 33的致死率处于中间水平（经颅内接种时致死率较低，经腹腔内接种时致死率为零）；（2）AG80 - 646经腹腔内接种对兔子的毒性比三种流行株Cba 87、Cba CIV 180和麦克米伦株更强；（3）AG80 - 646对新生鸡的毒性低于阿根廷流行株Cba CIV 180；（4）在每个动物宿主中，病毒血症水平始终与毒株毒力相关。本研究为未来南美洲WEE生态学研究中区分WEE复合病毒和毒株提供了工具。
