Genotyping of Canadian isolates of fowl adenoviruses

Abstract

Five hundred and seventy-three clinical submissions with fowl adenovirus (FAdV) involvement were examined to investigate the association of different types of FAdV with clinical problems related to FAdV infection. Samples were received from 2000 to 2006 and originated from seven Canadian provinces. Four hundred and eighty-seven submissions were inclusion body hepatitis (IBH) related, while 86 were not IBH related. Viruses isolated from 287 samples were further analysed by hexon gene loop 1 sequencing. Twenty-seven genotyped FAdVs were from Alberta, 20 from British Columbia, 16 from Manitoba, one from Nova Scotia, 82 from Ontario, 64 from Quebec and 77 from Saskatchewan. Two hundred and forty-six analysed FAdVs were from IBH cases, confirmed by liver histopathology, by FAdV isolation from the liver, or both. Based on hexon gene loop 1 sequencing analysis, FAdVs associated with IBH outbreaks were genetically related to FAdV02 (nine isolates, 99.4%), FAdV08a (100 isolates, 99.4% to 100%) and FAdV11 (98 isolates, 99.4% to 100%). Thirty-nine viruses were 93.7% to 94.3% identical to FAdV07 strain x11a, but the genetic and immunogenic properties of this strain require further investigation. In IBH cases, the co-infection rates for infectious bursal disease virus, infectious bronchitis virus, reoviruses and Newcastle disease virus were 3.47%, 1.04%, 6.25% and 0.69%, respectively. Forty-one genotyped FAdVs were from "non-IBH" cases. Viruses isolated from non-IBH cases consisted of 22 FAdV01, 15 FAdV11, two FAdV08a and one each of FAdV02 and FAdV04 viruses. Co-infection rates in non-IBH submissions were 50.00% for infectious bursal disease virus, 40.70% for infectious bronchitis virus, 27.91% for reoviruses and 1.16% for Newcastle disease virus.

Characterization of fowl adenoviruses associated with hydropericardium syndrome and inclusion body hepatitis in broiler chickens

“…Based on REA pattern, 36.4 and 48.5 % of the positive samples had FAdV-4 and FAdV-8, respectively, indicating them to be the predominant serotypes. Predominance of FAdV-8 in Canada and the increase in isolations of this serotype over the years have been reported [16]. The REA pattern revealed the presence of FAdV-2, FAdV-5, FAdV-6, FAdV-7 and FAdV-12 serotypes in addition to FAdV-4 and FAdV-8 in this study.…”

“…In the present study, 12 of the 33 FAdV positive samples contained two serotypes indicating mixed infections with different serotypes during same outbreak. Mixed infections of FAdV-1 and FAdV-8, and that of FAdV-7 and FAdV-1 have been reported earlier in IBH affected flocks [8,16]. It is not clearly understood whether the presence of two serotypes has any effect on the severity of clinical disease.…”

“…The HR 1 clustered with reference FAdV- [10,12,13]. The primers designed from hexon gene have been used in PCR for detection of fowl adenovirus [5,13,16,22] and amplify all reference strains of FAdV [12].…”

“…Conventionally, IBH/HPS outbreaks are diagnosed on the basis of clinical signs, gross pathological lesions, histopathology and/or agar gel precipitation test [1,14,15]. Molecular techniques like polymerase chain reaction followed by restriction enzyme analysis (REA) and sequencing have been used for the rapid detection and differentiation of FAdVs [4,5,9,10,12,16]. The present study was undertaken to detect and characterize the FAdVs from field outbreaks of IBH/HPS in broiler chickens in Haryana, a north-western state of India, to generate epidemiological information that could be helpful in the formulation of an effective vaccination strategy.…”

Occurrence of Aviadenovirus in chickens from the poultry industry of Minas Gerais

“…Results indicate that the industrial and free-range chickens evaluated in Minas Gerais were infected with Aviadenovirus D species. A sequence of serotype 11, previously detected in Brazil (Accession number FJ360747, Chacón et al, 2008;unpublished) and two strains described in Canada, 04-52447 (Accession number A7L8U1) and 05-50052-2485-O-CT (Accession number A7L8E2) (Ojkic et al, 2007;unpublished), were grouped in the same branch. Isolates PM34 and PM35 were grouped with serotype 11 strain (São Paulo) and fowl adenovirus D strains 04-52447 and 05-50052-2485-O-CT (Ojkic et al, 2007, Canada, unpublished, submitted to EMBL/GenBank/DDBJ databases).…”