Enteric Viruses Detected by Molecular Methods in Commercial Chicken and Turkey Flocks in the United States Between 2005 and 2006

Abstract

Intestinal samples collected from 43 commercial broiler and 33 commercial turkey flocks from all regions of the United States during 2005 and 2006 were examined for the presence of astrovirus, rotavirus, reovirus, and coronavirus by reverse transcription-polymerase chain reaction (PCR), and for the presence of groups 1 and 2 adenovirus by PCR. Phylogenetic analysis was performed to further characterize the viruses and to evaluate species association and geographic patterns. Astroviruses were identified in samples from 86% of the chicken flocks and from 100% of the turkey flocks. Both chicken astrovirus and avian nephritis virus (ANV) were identified in chicken samples, and often both viruses were detected in the same flock. Turkey astrovirus type-2 and turkey astrovirus type-1 were found in 100% and 15.4% of the turkey flocks, respectively. In addition, 12.5% of turkey flocks were positive for ANV. Rotaviruses were present in 46.5% of the chicken flocks tested and in 69.7% of the turkey flocks tested. Based upon the rotavirus NSP4 gene sequence, the chicken and turkey origin rotaviruses assorted in a species-specific manner. The turkey origin rotaviruses also assorted based upon geographical location. Reoviruses were identified in 62.8% and 45.5% of chicken and turkey flocks, respectively. Based on the reovirus S4 gene segment, the chicken and turkey origin viruses assorted separately, and they were distinct from all previously reported avian reoviruses. Coronaviruses were detected in the intestinal contents of chickens, but not turkeys. Adenoviruses were not detected in any chicken or turkeys flocks. Of the 76 total chicken and turkey flocks tested, only three chicken flocks were negative for all viruses targeted by this study. Most flocks were positive for two or more of the viruses, and overall no clear pattern of virus geographic distribution was evident. This study provides updated enteric virus prevalence data for the United States using molecular methods, and it reinforces that enteric viruses are widespread in poultry throughout the United States, although the clinical importance of most of these viruses remains unclear.

Detection and molecular characterization of enteric viruses in enteritis-affected commercial broiler chickens in India

“…In one study, Pantin-Jackwood et al (2007) found commercial turkeys to be negative for ARVs in the US. In a subsequent study, however, these authors (Pantin-Jackwood et al, 2008) reported ARVs in 62.80% of the chicken flocks and 45.50% of the turkey flocks tested. Previous studies have reported the presence of ARV in intestinal/faecal samples of broiler chickens (Koo et al, 2013;Mettifogo et al, 2014) although most of these studies indicated low prevalence of ARV as compared to other enteric viruses.…”

“…Pantin-Jackwood et al (2008) also reported that three of the 43 broiler chicken flocks were negative for enteric viruses (astrovirus, reovirus, rotavirus and coronavirus). There are a number of factors (viruses, bacteria, protozoa, nutritional and management) other than the tested viruses that can cause enteritis.…”

“…The extracted RNA templates were subjected to RT-PCR individually for CAstV, ANV and ARV using virus-specific primers. Primers for polymerase gene of CAstV (F-5'-GAYCARCGAATGCGRAGRTTG-3' and R-5'-TCAGTGGAAGTGGGKARTCTA-3') with a product size of 362 bp; polymerase gene of ANV (F-5'-GYTGGGC GCYTCYTTTGAYAC-3'and R-5'-CRTTTGCCCKRTARTCT TTRT-3') with a product size of 473 bp ; and S4 gene of ARV (F-5'-GTGCGTGTTGGAGTTTCCCG-3' and R-5'-TACGCCATCCTAGCTGGA-3') with an expected product size of 1120 bp (Pantin-Jackwood et al, 2008) were used. Amplification for all three viruses was carried out using OneStep RT-PCR kit (Qiagen, USA).…”

“…Several pathogens such as avian rotavirus, astrovirus, reovirus, coronavirus, adenovirus, Salmonella, Escherichia coli, Enterococcus, and Eimeria spp. have been detected either alone or in different combinations from broiler chickens and turkey flocks afflicted with enteritis (Barnes et al, 2000;Jindal et al, 2010;Pantin-Jackwood et al, 2007, 2008Day and Zsak, 2013;Koo et al, 2013;Mettifogo et al, 2014).…”

“…Serological studies suggested widespread prevalence of ANV infections in commercial broiler chickens in various countries (Imada et al, 1980;Connor et al, 1987). In recent years, ANVs have been detected in enteritis-or RSS-affected broiler chickens from many different countries by molecular methods (Pantin-Jackwood et al, 2008;Smyth et al, 2009;Roussan et al, 2012;Koo et al, 2013;Mettifogo et al, 2014).…”