Molecular Detection and Phylogenetic Analysis of Chicken Astrovirus Associated with Poultry Enteritis

Abstract

Background: Poultry enteritis is an important multifactorial disease. Chicken Astrovirus (CAstV) usually associated with enteritis. The aim of this study was to investigate the occurrence of CAstV in poultry enteritis cases, its molecular characterization, phylogenetic analysis and gross and microscopic examination of intestine and liver specimen affected with CAstV. Methods: Total 604 dead poultry birds from commercial poultry farms affected with enteritis were examined for presence of CAstV. Intestinal samples of four birds were pooled to make one biological sample. CAstV was detected by reverse transcriptase PCR (RT-PCR) using ORF-1b gene specific primers. Molecular characterization was carried out by partial gene sequencing. Result: CAstV was detected in 20.52% (31/151) of samples. Highest prevalence (49.29%) was observed in 0-1 week old chicks. The partial molecular characterization revealed high similarity of the nucleotide sequence from India (97% to 93%) and from USA, Brazil, Poland and Korea (94 to 92%). Further similarity of amino acid sequences of CAstV from India (100% to 98%) and from USA, Brazil, Poland and Korea (98 to 97%) was observed. Histopathological examination revealed villous atrophy, congestion and atrophic cystic glands in sub-mucosa of intestine. Further severe congestion and hemorrhages along with infiltration of inflammatory cells in liver parenchyma was observed.