Molecular characterization of chicken astroviruses in gout-affected commercial broiler chickens in Haryana, India

Abstract

Chicken astroviruses (CAstVs) infect young chicks and are associated with gastroenteritis, stunted growth or visceral gout (gout). True incidence and distribution of CAstVs as well as virus variants circulating in India is not well understood. In this study, 80 gout-affected broiler chicken flocks from Haryana, a north-western state of India, were tested for the presence of astroviruses by targeting the polymerase gene of both CAstV and avian nephritis virus (ANV) and capsid gene of CAstV. Of these, 22 (27.5%) flocks were found positive for CAstV, 7(8.75%) for ANV and 2 (2.5%) for both CAstV and ANV genome by reverse-transcription-polymerase chain reaction. CAstV was isolated by inoculating tissue (kidney) homogenate from gout-affected birds into specific-pathogen free embryonated chicken eggs where the infected embryos showed stunted growth with necrosis of liver and enlarged kidney with urate deposits. Capsid gene-based phylogenetic analysis revealed the clustering of CAstV strains from this study with Indian strains of serogroup Biii suggesting their antigenic relatedness. Thus the present study reveals the presence of chicken astroviruses in broiler chickens affected with gout.

A Review of the Emerging Poultry Visceral Gout Disease Linked to Avian Astrovirus Infection

“…Symptoms including visceral gout after CAstV infection were also reported worldwide [ 12 , 15 ]. Furthermore, CAstV-affected chicks showed distended ureters with uricacid deposition, and visceral and articular gout [ 16 ].…”

“…Like other RNA viruses, astrovirus polymerase has no proofreading function in the process of replication. It is easy to make mistakes in the process of virus replication, leading to an increase in the mutation rate of the virus, and high genetic diversity and recombination potential [ 1 , 4 , 12 , 15 ]. This recombination between different strains of astroviruses has aggravated the prevention of astrovirus infection [ 4 , 11 , 16 ].…”

“…The major post-mortem findings were swollen kidneys, prominent ureters and visceral gout. CAstV-infected embryos revealed stunted growth, liver necrosis and enlarged kidney with deposition of urate crystals [ 15 ]. In 2011 and 2012, India reported a 40% mortality rate of broilers with visceral and articular gout [ 16 ], the pathogen of which was identified as India subgroup Biii CAstV [ 12 , 15 ].…”

“…CAstV-infected embryos revealed stunted growth, liver necrosis and enlarged kidney with deposition of urate crystals [ 15 ]. In 2011 and 2012, India reported a 40% mortality rate of broilers with visceral and articular gout [ 16 ], the pathogen of which was identified as India subgroup Biii CAstV [ 12 , 15 ]. When inoculation with CAstV-infected kidney homogenate, 1 day-old SPF chickens showed a high mortality (67.5–100%), and autopsy showed that all chickens suffered from swollen kidneys, prominent ureters, and visceral gout.…”

Metagenomic sequencing determines complete infectious bronchitis virus (avian Gammacoronavirus) vaccine strain genomes and associated viromes in chicken clinical samples

“…Chicken astrovirus is an enteric poultry virus that was identified only in 2004 [ 55 ] as a separate species of avian astrovirus. It has been documented globally as an enteric virus in poultry with studies from Poland [ 56 ], Jordan [ 57 ], India [ 58 , 59 ], Nigeria [ 60 ], China [ 61 ], Korea [ 62 ], and Brazil [ 63 ].…”