Antibodies anti-infectious bursal disease virus and viral genome detection in broilers and chickens backyard at Bahia's poultry production area/Anticorpos contra o virus da doenca infecciosa bursal e deteccao do genoma viral em criacoes de frango de corte e galinhas de quintal no polo avicola da Bahia

The aim of this study was to determine the frequency of antibodies anti-Infectious Bursal Disease Virus as well as to detect the virus in broilers and chicken backyard, raised in two different regions at Bahia's poultry production area. A total of 758 serum samples were collected from broilers and 320 from chicken backyard, in order to assess the frequency of antibodies using an indirect ELISA. For virus detection and characterization it was collected 6 bursal pools from broilers and 3 from chicken backyard, which were further analyzed with PCR/RFLP. The results showed that there is no uniform protection in commercial flocks of the two different regions, suggesting that it may be occurring vaccination errors and that it may be occurring challenge from viruses at the environment. High titers were observed in no vaccinated chicken backyard. Molecular tests revealed that 3 broilers pools were positive in which 2 matched the vaccine strain (G3) and 1 a variant strain (G15). One sample from free-ranging chickens was positive for the variant strain (G15). These results demonstrate the need for monitoring both types of exploration. Key words: Infectious Bursal Disease, ELISA, serology, PCR, molecular biology, chickens. Este estudo teve como objetivo determinar a frequencia de anticorpos e detectar o genoma viral do virus da Doenca Infecciosa Bursal em criacoes de frangos de corte e em criacoes de subsistencia localizadas em duas regioes do polo avicola da Bahia. Foram coletadas 758 amostras de soro de frangos de corte e 320 amostras de galinhas de quintal para avaliacao da frequencia de anticorpos utilizando ELISA indireto. Para a deteccao e caracterizacao do virus foram coletados 6 pools de bursas de Fabricius em frangos de corte e 3 pools em criacoes de subsistencia, analisados posteriormente com PCR/RFLP. Os resultados revelaram que nao ha protecao uniforme na criacao comercial nas duas regioes estudadas, sugerindo falha na vacinacao e desafio com virus no ambiente. TambEm observaram-se altos titulos em galinhas de quintal nao vacinadas, com variacao nos titulos relacionada com desafios de campo. Nos testes moleculares, verificaram-se que tres pools de frangos de corte eram positivos, sendo dois para cepa vacinal (G3) e um para cepa variante (G15). Nas criacoes de subsistencia, houve uma amostra positiva para cepa variante (G15). Os resultados demonstram a necessidade de monitoramento em ambas as criacoes. Palavras--chave: birnavirus, ELISA, sorologia, biologi