Epidemiological and pathological investigation of fowl aviadenovirus serotypes 8b and 11 isolated from chickens with inclusion body hepatitis in Spain (2011–2013)

Abstract

Inclusion body hepatitis caused by different fowl aviadenovirus (FAdV) serotypes has been described in several countries in recent years. In Spain, from the spring of 2011 to 2013, an increased number of outbreaks in broiler and broiler breeder flocks from different regions occurred. The objectives of the present work were to carry out the molecular characterization of FAdV strains from Spanish inclusion body hepatitis cases and to study the pathogenicity and viral dynamics of these strains in specific pathogen-free (SPF) chickens. A total of 52 inclusion body hepatitis clinical cases, including 45 from broiler farms and seven from broiler breeder farms, were analysed by conventional polymerase chain reaction and sequencing targeting the FAdV hexon gene. From these, 37 strains were classified as FAdV type 8b, while the remaining 15 were classified as FAdV types 11 (n = 10), 2 (n = 4) and 8a (n = 1). In addition, two different FAdVs belonging to the genotypes 8b and 11 were used for experimental infection. Specific pathogen-free five-day-old birds were inoculated intramuscularly with a high (10 tissue culture infective dose (TCID)/ml) or low (10 TCID/ml) dose of the above-mentioned FAdVs. No mortality was observed in any of the experimental groups, and only one bird showed evident clinical signs. However, macroscopic and microscopic hepatic lesions, as well as viral DNA, were detected in birds from all infection groups. Inclusion bodies and viral DNA were also detected in the pancreas and in the small and the large intestine in some birds. Long-lasting shedding and transmission to contact birds were confirmed in all infected groups.

Identification of four serotypes of fowl adenovirus in clinically affected commercial poultry co‐infected with chicken infectious anaemia virus in Trinidad and Tobago

“…Phylogenetic analysis of the FAdV L1 hexon gene revealed dominance of three different FAdV serotypes (FAdV‐8a, ‐8b, ‐11), belonging to two species, FAdV‐D and FAdV‐E, in chicken flocks in Trinidad. This finding is similar to reports in other countries where type members of species FAdV‐D and FAdV‐E are most prevalent (Morshed, Hosseini, Langeroudi, Fard, & Charkhkar, ; Ojkic et al., ; Oliver‐Ferrando et al., ). Additionally, we also determined the presence of FAdV‐9, a species FAdV‐D affiliated type, which is infrequently reported worldwide.…”

Isolation and characterization of fowl aviadenovirus serotype 11 from chickens with inclusion body hepatitis in Morocco

“…In recent years, the clinical cases of IBH have been increasing all over the world [25], resulting in considerable economic losses in many countries, such as USA [26], India [27], Canada [28], Hungary [29], Korea [30], Lebanon [31] and Spain [32]. Most of these outbreaks have been associated with genotypes FAdv-D or–E, with serotypes 2, 11, 8a and 8b being the most frequently involved [25].…”

“…Indeed, the presence of INIB in hepatocytes have been shown by inoculation of FAdV to specific pathogen free (SPF) embryonated eggs via the chorioallantoic membrane and was observed at 5–6 dpi and the adenovirus particles were identified in liver samples of embryos by transmission electron microscopy [36]. Furthermore, SPF chickens infected with different strains of FAdV showed the presence of INIB in hepatocytes at the histological examination of liver tissues [32, 37, 38].…”

“…The nucleotide sequences analysis showed that the three FAdV isolates belonged to FAdV serotype 11 of the D genotype group. This strain was responsible for different inclusion body hepatitis outbreaks in poultry in Canada [28], China [59], Hungary [29], Australia [38], Lebanon [31], Spain [32] and Iran [60].…”

Characterisation of fowl adenovirus (FAdV-8b) strain concerning the geographic analysis and pathological lesions associated with inclusion body hepatitis in broiler flocks in Turkey

“…In Lebanon, FAdV-11 was found in commercial broiler flocks (32), and in Iran, two FAdV species D and E (FAdV-11, FAdV-8b) were linked with outbreaks of IBH (7,16,18). Similarly, an investigation of the outbreaks of IBH in Australia, South Africa, Austria, and Spain reported FAdV-8b or FAdV-11 in broiler flocks (10,24,30,34). Also, an epidemiological investigation of outbreaks of FAdV in commercial chickens in Korea indicated that all FAdVs types 8b and 11 had relevance to IBH lesions (2).…”