The occurrence of Orthoreovirus, Rotavirus and chicken anemia virus in chickens of the poultry industry in Minas Gerais, Brazil

Abstract

Fifty-four fecal samples taken from broiler chickens from 1 to 45 days of age, and of pullets from 10 to 13 weeks of age, original from eight different poultry regions in the state of Minas Gerais, Brazil, were collected from March 2008 to January 2010 for avian Orthoreovirus (ARV) and avian Rotavirus (AvRV) analyses. For the assay of ARV, RNA was immediately extracted (Trizol) and transcribed into cDNA for assaying in a nested-PCR with ARV-specific primers. For AvRV, polyacrylamide gel electrophoresis (PAGE) was performed with RNA extracts obtained by phenol-chloroform extraction. CAV was additionally investigated through a nested-PCR of thymus and spleen. Results found 5.55% positive for ARV and 9.25% for AvRV. Also, CAV and ARV genomes were detected in co-infection, in a highly prostrated and claudicating chicken flock. No ARV or AvRV infections were detected in pullets. Material of a clinically affected flock was inoculated into SPF embryos, resulting in embryonic hemorrhage, whitish foci in the chorio-allantoic membrane and death. Sequencing of ARV amplicons and isolate cDNA grouped local strains with the ARV S1133 strain, historically used in live vaccines, suggesting the continued circulation of this vaccine virus strain in intensive poultry regions. Detection rates for ARV and AvRV, as well as the presence of CAV, were additionally indicative of failing biosecurity strategies for the intensive poultry regions examined.Keywords: Broiler, layer, chicken anemia virus, CAV, avian reovirus, ARV, avian rotavirus, AvRV, nested-PCR, PAGE. RESUMO Avaliou-se a ocorrência de Orthoreovirus (ARV) e Rotavirus (AvRV) aviários na avicultura industrial de

Occurrence of Aviadenovirus in chickens from the poultry industry of Minas Gerais

“…Avian Orthoreovirus was an additional cause of immunosuppression described previously in our region (Rios et al, 2012), and may complicate further the complex epidemiology of chicken viruses in the field.…”

“…Free-range chickens FAdV status was previously unknown in Brazil, although the scientific literature had suggested widespread infection in chickens (Cho, 1976;McFerran et al, 1976). A potentially negative role for FAdV is considered on productivity and performance, most importantly taking into consideration the potential co-infections by locally studied CAV (Barrios et al, 2009), IBDV (Gomes et al, 2005) and avian Orthoreovirus (Rios et al, 2012).…”

“…On the other hand, other studies consider FAdV mostly as a secondary pathogen, with pathogenesis resulting from a combined infection with immunosuppressive agents, such as chicken anemia virus (CAV) (Toro et al, 2000) or mycotoxins (Singh et al, 1996). Differences in results may be based on differences in virulence among isolates of the same or different serotype (McFerran and Smyth, 2000), as well as the differences in chicken susceptibility (Roy et al, 2004).…”

<b>Análise multigênica de rotavírus do grupo A em aves de criações comerciais brasileiras</b>

“…As frequências de ocorrência deste estudo são semelhantes àquelas descritas anteriormente em nosso país (ALFIERI et al, 1989;TAMEHIRO et al, 2003;VILLARREAL et al, 2006;ASANO et al, 2011;SILVA et al, 2011;RIOS et al, 2012;BESERRA et al, 2014a;METTIFOGO et al, 2014 TROJNAR et al, 20009). No entanto, sabe-se também que a transmissão interespécie entre AvRV e RV de mamíferos ocorre naturalmente (BRUSSOW et al, 1992), já tendo sida descrita inclusive no Brasil (ASANO et al, 2011;SILVA et al, 2012;BESERRA et al, 2014a) Como demonstrado na figura 6, as amostras aqui caracterizadas pertencentes ao genotipo E10, apresentam baixo nível de diversidade genética e estão mais relacionadas com as demais amostras brasileiras (SILVA et al, 2013).…”

“…No Brasil, rotavírus do grupo A (RVA) foram primeiramente detectados, através das técnicas de PAGE e ELISA, em fezes de frango de corte com diarreia nos estados de Minas Gerais e Paraná (ALFIERI et al, 1989) e posteriormente descritos em amostras fecais de frango de corte, poedeiras e matrizes em estados das regiões norte, nordeste, centro-oeste, sudeste e sul do país (TAMEHIRO et al, 2003;VILLARREAL et al, 2006;RIOS et al, 2012;SILVA et al, 2013;METTIFOGO et al, 2014;BESERRA et al, 2014a), além de criações comerciais de perus (ASANO et al, 2011;MOURA-ALVAREZ et al, 2014) (McNULTY, 2008;TROJNAR et al, 2009;JOHNE et al, 2011;KATOOR et al, 2013;STUCKER et al, 2015;FALCONE et al, 2015). No Brasil, RVD foi primeiramente detectado na região norte (BEZERRA et al, 2012;BEZERRA et al, 2014) e em seguida nos estados de São Paulo, Paraná e Goiás, em amostras de frango de corte, matrizes e poedeiras comerciais sem sintomas de diarreia (BESERRA et al, 2015).…”