Growth analysis of adenoviruses isolated from pigeons in chicken cells and serological characterization of the isolates.

The susceptibility of chicken embryo liver (CEL) and chicken kidney (CK) cells to eight adenoviruses isolated from different pigeons were investigated. Isolation and propagation was most successful in CEL cells. The cytopathic effect, i.e. cell rounding and detachment of the cells was typical for adenoviruses. Titres of up to 10(6.6) plaque-forming units/ml could be reached on CEL cells. Transferring CEL-grown virus onto CK cells also resulted in a cytopathic effect but with much lower titres, whereas the isolation of pigeon adenoviruses on these cells was not successful. Antibodies against fowl adenovirus reference strains (FAV1-12) were used to serotype the isolates in neutralisation tests. Six were identified as FAV serotypes 2,5,6,10 and 12. Two isolates could not be typed. An antiserum produced in chickens against one of these untypable strains was able to neutralize both. The neutralization indexes of these strains were very similar, indicating that they are probably the same serotype. A cross neutralization test confirmed that this serotype is different from known fowl adenoviruses.