Phylogenetic diversity of avian nephritis virus in Hungarian chicken flocks

Abstract

Avian nephritis virus (ANV) infection was detected in 4-day-old to 22-day-old chickens collected on Hungarian farms between 2002 and 2005. The animals suffered from diarrhoea, growth retardation, runtingstunting syndrome, and 2 to 6% mortality was reported. Tubulonephrosis, interstitial nephritis and uricosis (gout) was diagnosed. The presence of ANV RNA was detected in chicken carcasses using reverse transcriptase-polymerase chain reaction. The virus was demonstrated in 69% of the investigated farms. The nucleotide sequence of the amplification products (corresponding to part of the genome that encodes the GP1 protein) was determined and phylogenetic analysis was performed. The nucleotide sequences showed 76 to 86% identity to the reference strain isolated in 1976 in Japan. The constructed phlyogenetic tree indicates high diversity of the Hungarian ANV sequences, regardless of their origin and year of sample collection. Analysis of the putative amino acid sequences encoded by the partial GP1 sequences also revealed high diversity of the virus. Even samples collected at the same farm, at the same time but from different flocks, differed in nucleotide and putative amino acid sequences. The possible effects of the sequence diversity on the pathogenicity, antigenicity and diagnostics of ANV are discussed.

Detection and characterization of avian nephritis virus in ducklings

“…Imada & Kawamura (2003) found lymphoid follicles 14 to 28 days post infection in chickens experimentally infected with ANV. With reference to the examination conducted in this report, ANV infection in ducks showed lesions similar to those described in chickens (Imada & Kawamura, 2003;Mándoki et al, 2006). These histopathological findings gave us directions for the confirmation of ANV presence in the intestine samples by molecular methods.…”

“…Rather diffuse pericryptal lymphocyte hyperplasia and fibroplasia were found in the duodenum ( Figure 5). In addition to the degeneration and the presence of inclusion bodies in some of degenerated epithelial tubular cells as well as the moderate interstitial infiltration by lymphocytes (Meulemans, 2008;Mándoki et al, 2006), focal mononuclear cellular hyperplasia has also been identified in later stage of infection with ANV (Narita et al, 1990b;Imada & Kawamura, 2003;Mándoki et al, 2006). Imada & Kawamura (2003) found lymphoid follicles 14 to 28 days post infection in chickens experimentally infected with ANV.…”

Detection and characterization of a new astrovirus in chicken and turkeys with enteric and locomotion disorders

“…This pathogenicity of isolate 19 was observed after infection of 3-week-old SPF layers, whereas several strains of ANV-1 caused considerable mortality in 1-day-old SPF chicks but not in older birds (Imada et al, 1981;Frazier et al, 1990;Narita et al, 1990;Shirai et al, 1991aShirai et al, , b, 1992Reece et al, 1992). These differences can be explained by the different type of ANV strains, by strain of bird, route of inoculation or level of maternally derived antibodies; other experimental conditions should also be taken into account (Mandoki et al, 2006;Reynolds & Schultz-Cherry, 2008). It would also be very interesting to compare the pathogenicity of more strains of the ANV-3 group.…”

Identification of chicken enterovirus-like viruses, duck hepatitis virus type 2 and duck hepatitis virus type 3 as astroviruses

“…However, sequence comparisons involving other genome regions including the capsid protein gene will be required to determine the exact relationship of ELV-1 to ANV-1 and other ANV isolates. Based on sequence comparisons of part of the non-structural protease gene (ORF 1a), Mandoliki et al (2006) have recently shown that ANV can be grouped into three genotypes.…”