Serological characteristics of avian reoviruses of Australian origin

Abstract

SUMMARYThe antigenic relationship of plaque purified avian reoviruses isolated from commercial chickens in Australia was determined with a serum neutralisation procedure using antisera prepared in rabbits. Ten selected isolates were assigned to three groups based upon relatedness values determined by cross-neutralisation studies. Considerable crossreactivity was demonstrated against heterologous types and the three groups were considered to be subtypes rather than distinct serotypes.

Adaptation and characteristics of replication of a strain of avian reovirus in vero cells

“…In chicken cells, avian reovimses appear to be released from infected cells more readily: after only one freeze-thaw cycle of virus infected chicken cells titres equivalent to those obtained in Vero cells have been obtained. The more cell-associated nature of the reovirus in Vero cells than in chicken cells was also indicated by the need to incubate Vero-infected cells for 10 days to obtain maximum CPE and easily detectable plaque development, whereas in chicken cells the period of incubation required to produce plaques of equivalent size to those obtained in Vero cells was only 4 days and was similar in all reovirus isolates which were examined (Robertson and Wilcox, 1984). The 10 day incubation period required was in contrast with reports by Barta et al (1984) and Sahu and Olson (1975) that plaques on Vero cell monolayers were detectable after incubation for 4 to 5 days and 5 to 6 days respectively.…”

“…At least three antigenic groups of avian reoviruses have been demonstrated to be present in Australia; all three groups exhibited considerable cross-reactivity, in neutralisation tests, and the RAM-1 strain appeared to be intermediate between two of the groups designated as B and C (Robertson and Wilcox, 1984). Due to the broad antigenic cross-reactivity of this strain with other antigenic types of reovirus in Australia, it would be a suitable strain to use in serum neutralisation tests if only a single antigenic type were used to assess the antibody titre of chickens to heterologous strains.…”

“…Primary cultures of chicken kidney (CK) cells were prepared using procedures previously described (Robertson and Wilcox, 1984).…”

“…All viruses were plaque-purified as previously described (Robertson and Wilcox, 1984). Attempts to adapt each virus to Vero cells were performed by inoculating 0.5 ml of virus suspension from infected CK cells onto confluent monolayers of Vero cells in 60 mm tissue culture dishes at a multiplicity of infection (MOI) of 1.0, absorbing for 1 hour at 37°C in a humidified 5% CO2-in-air atmosphere, and replacing the inoculum with 5 ml of DMEM plus 2% FCS, 100 i.u./ml penicillin and 100 /ig/ml streptomycin.…”

Type‐specific antigenicity of avian reoviruses

“…One study detected 11 serotypes (Wood et al, 1980) and cross-neutralization between viruses in different serogroups and one-way neutralization between some heterologous viruses (Wood et al, 1980;Hieronymus et al, 1983;Robertson and Wilcox, 1984) was demonstrated.…”