CORONAVIRUS, CHICKEN, NEW - BRAZIL
************************************ A ProMED-mail post
ProMED-mail is a program of the International Society for Infectious Diseases
Date: Tue 1 Apr 2003
From: Paulo Brandao
Novel Coronavirus Detected in Chicken Intestinal Contents
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We have just found a coronavirus in intestinal contents of a chicken by a PCR targeted to the RNA-dependent RNA polymerase gene (pol gene). Sequence analysis of this gene showed that, though it is grouped closely with bovine coronavirus and is distantly related to infectious bronchitis virus, it has low nucleotide identity to all known coronaviruses. The birds were 15 days old and had no clinical sign of any disease. These findings are quite similar to those associated with the coronavirus implicated in SARS.
We are now trying to sequence other isolates.
-- Laura Yaneth Villarreal Buitrago & Paulo Eduardo Brandao
College of Veterinary Medicine
University of Sao Paulo
Brazil
[Currently the genus _Coronavirus_ comprises 13 virus species, which fall into 3 distinct phylogenetic groups:
Group 1 contains canine, feline, human, and porcine coronavirus species.
Group 2 contains bovine, human, murine, rat, and turkey coronavirus species.
Group 3 contains the single species (avian) infectious bronchitis virus.
In viruses belonging to Groups 2 and 3 the S (spike) protein is cleaved into S1 and S2 subunits, whereas the S protein remains uncleaved in group 1 viruses. Drs. Buitrago and Brandao state that their virus is closer to bovine coronavirus (group 2) than avian infectious bronchitis virus (group 3). The relationship of their virus to group 1 viruses is unclear, and the cleavability of the S protein is a characteristic of some relevance here.
The genus _Coronavirus_ comprises a diverse group of viruses with different pathological potentials; hence it is no surprise that novel coronaviruses will continue to be identified. Characterization of virus species on the basis of short nucleotide sequences obtained by PCR procedures must be treated with caution until the virus can be isolated in an infectious form. Until sequence data for the presumptive SARS agent are made generally available, it is premature to relate this chicken coronavirus in any way to the SARS agent.
Further detailed characterization of this novel coronavirus is awaited with interest. - Mod.CP]