Isolation of avian nephritis virus from chickens showing enteric disorders

Abstract

Runting-stunting syndrome (RSS) is one of the diseases associated with many detected viruses. In Brazil, there were reports of several enteric disease outbreaks in chickens in which avian nephritis virus (ANV) was detected; however, the role of ANV in the outbreaks and whether the virus was a causative agent of these cases of enteric diseases were not determined. The aim of this study was to isolate ANV in specific pathogen-free (SPF) chicken embryonated eggs (CEE) from the enteric contents of chickens showing signs of RSS. For this purpose, 22 samples of chicken enteric contents that were positive only for ANV were inoculated into 7 and 14-day-old SPF-CEE via the yolk sac route and incubated for 5 d, with a total of 3 passages. Virus isolation was confirmed by the presence of embryo injuries, detection of viral RNA by RT-PCR, and visualization of viral particles using electron microscopy. Therefore, the 7-day-old inoculated embryos showed dwarfism, gelatinous consistency, hemorrhage, and edema in the embryos, whereas the 14-day-old did not show any alteration. Viral RNA was detected in the embryos of both ages of inoculation, and the same viral particles were visualized. The embryos from the mock group showed no alteration and were negative for all the tests. The viral cDNA was sequenced, and the molecular and phylogenetic analyses showed that the Brazilian isolates are more related with the ANV-1 serotype group; the sequences of these isolates showed a high percentage of nucleotide (86.4 to 94.9%) and amino acid (92.3 to 98.7%) similarity with other sequences from China, Japan, Australia, and the United States that belong to this serotype previously classified group. In this study, we isolated 8 samples of ANV in SPF-CEE from enteric content samples from chickens with RSS. In doing so, we showed the pathological injuries to the embryo caused by the virus and the molecular characterization of a part of the ORF 1b gene of the virus.

First Isolation and Molecular Characterization of Chicken Astrovirus and Avian Nephritis Virus in Chickens in Bangladesh

“…Next, inoculated CEEs were maintained in an automated egg incubator with a constant temperature of 37.5 °C to 38 °C and humidity of 40–55% for 5 days. The protocol of virus isolation was carried out according to the protocol described by Nunez et al for CAstV and Nunez et al for ANV ( 27 , 35 ).…”

“…At a young age, infected chicks were observed to have pale-to-white–colored plumage with a brown plumage ring over the neck and head, and the liver was enlarged and had a bronze or greenish color. However, in many cases, both CAstV and ANV were isolated from apparently healthy birds ( 25 – 27 ).…”

The First Whole Genome Sequence and Characterisation of Avian Nephritis Virus Genotype 3

“…The histological findings were of renal degeneration and inflammation, lesions from the necrosis of tubular cells, and signs of pneumonitis around the parabronchi [17]. Other manifestations observed in the embryos included dwarfism, gelatinous consistency, oedema, haemorrhages, lesions, swollen kidneys, dilated ureters, urate deposits across the viscera, heart, and kidneys, and mortality [14,[50][51][52].…”

The Landscape of Interactions between Hypoxia‐Inducible Factors and Reactive Oxygen Species in the Gastrointestinal Tract

“…The gastrointestinal tract (GT) is the major place of nutrient digestion and absorption, and it is prone to oxidative destruction by highly reactive oxygen species (ROS) [ 1 , 2 ]. Reactive oxygen species are byproducts of normal cellular metabolism.…”