Interactions between Marek's disease virus Rispens/CVI988 vaccine strain and adenovirus field strain in chicken embryo fibroblast (CEF) cultures.

The aim of the study was to determine the influence of adenovirus infection on the replication of Marek's disease virus vaccine strain Rispens/CVI988 during in vitro co-infection studies. Adenovirus field strain JN-5/10j was isolated from sick chickens. The study was conducted in chicken embryo fibroblast cultures (CEF). Monolayers of CEFs were infected with Rispens strain and field adenovirus strain JN-5/10j with different doses (10(1.0)-10(3.0) TCID50) in the following manner: a) simultaneously, b) first, infection with Rispens strain and after 24 h infection with adenovirus strain JN-5/10j and c) infection with adenovirus strain JN-5/10j 24 h before infection with Rispens strain. After 18, 24, 48, 72, and 96 h of incubation, the copy number of the pp38 gene of Rispens strain was determined using Real-time PCR. The results indicated that the Adenovirus infection before the infection with Rispens strain reduced the replication of the pp38 gene after 48 h by 2 log10.

Viral infections in goose flocks in Poland.

The aim of this study was to determine the infectious agents isolated from infection - suspected geese sent for the diagnostic examination to National Veterinary Research Institute. The birds were sent from goose flocks localized in different parts of Poland. Totally, 1,013 birds from 122 flocks were examined. The presence of goose parvovirus (GPV), goose haemorrhagic polyomavirus (GHPV), and goose circovirus (GoCV) was detected by triplex PCR. The presence of GPV DNA was shown in 36 flocks. The disease was most frequently diagnosed in goslings aging 3.5 weeks (ten flocks), and 2.5 weeks (six flocks). The analysis of the nucleotide sequence of VP1 encoding region has shown close similarity of Polish GPV strains within the group which ranged from 92% to 100%. Moreover, the similarity level of these strains with GPV isolated in Europe was from 91.3% to 100%. The occurrence of GoCV DNA was shown in 25 goose flocks. The presence of GoCV DNA was found among geese aged from 2 to 6 weeks, but predominantly in those aging 3.5 (three flocks) and 5 weeks (five flocks). The sequence analysis of PCR products from the sequenced region of ORFC1 capsid protein of GoCV has shown that Polish isolates share from 85% to 91% similarity with the sequences of GoCV strains isolated in other countries. The presence of DNA of GHPV was found in 3-week-old geese. During the last 2 years the presence of GHPV was confirmed in three flocks of goslings at the age from 3 to 3.5 weeks. During the last 12 years the occurrence of co-infection with GPV and GoCV was detected in six flocks aging from 5 to 6 weeks.