title: Infectious bronchitis virus in different avian physiological systems-a field study in Brazilian poultry flocks.
abstract: Avian infectious bronchitis is a highly contagious viral disease with economic effects on poultry agribusiness. The disease presents multi-systemic clinical signs (respiratory, renal, enteric, and reproductive) and is caused by one coronavirus (infectious bronchitis virus, IBV). Infectious bronchitis virus is classified into different serotypes and genotypes (vaccine strains and field variants). This study aimed to evaluate the occurrence of IBV in commercial poultry flocks from 3 important producing regions in Brazil and to determine the tropism of the main circulating genotypes to 3 different avian physiological systems (respiratory, digestive, urinary/reproductive). Clinical samples with suggestive signs of IBV infection were collected from 432 different poultry commercial flocks (198 from broilers and 234 from breeders). The total number of biological samples consisted of organ pools from the 3 above physiological systems obtained of farms from 3 important producing regions: midwest, northeast, and south. Infectious bronchitis virus was detected by reverse-transcription, real-time PCR of the 5' untranslated region. The results showed 179 IBV-positive flocks (41.4% of the flocks), with 107 (24.8%) from broilers and 72 (16.8%) from breeders. There were similar frequencies of IBV-positive flocks in farms from different regions of the country, most often in broilers (average 54%) compared with breeders (average 30.8%). reverse-transcription was more frequently detected in the digestive system of breeders (40%), and in the digestive (43.5%) and respiratory (37.7%) systems of broilers. Infectious bronchitis virus genotyping was performed by a reverse-transcription nested PCR and sequencing of the S1 gene from a selection of 79 IBV-positive flocks (45 from broilers and 34 from breeders). The majority of the flocks were infected with Brazilian variant genotype than with Massachusetts vaccine genotype. These results demonstrate the predominance of the Brazilian variant (mainly in the enteric tract) in commercial poultry flocks from 3 important producing regions in Brazil.
authors.affiliation: Laboratório de Diagnóstico Molecular, Universidade Luterana do Brasil (ULBRA), Av. Farroupilha, 8001, Prédio 22, Sala 312, Bairro São José, CEP 92425-900, Canoas, RS, Brazil.
authors.forename: Eder
authors.initials: E
authors.lastname: Balestrin
authors.affiliation: Laboratório de Diagnóstico Molecular, Universidade Luterana do Brasil (ULBRA), Av. Farroupilha, 8001, Prédio 22, Sala 312, Bairro São José, CEP 92425-900, Canoas, RS, Brazil.
authors.forename: Aline P
authors.initials: AP
authors.lastname: Fraga
authors.affiliation: Laboratório de Diagnóstico Molecular, Universidade Luterana do Brasil (ULBRA), Av. Farroupilha, 8001, Prédio 22, Sala 312, Bairro São José, CEP 92425-900, Canoas, RS, Brazil Simbios Biotecnologia, Rua Cai, 541, Vila Princesa Izabel, CEP 94940-030, Cachoeirinha, RS, Brazil.
authors.forename: Nilo
authors.initials: N
authors.lastname: Ikuta
authors.affiliation: Laboratório de Virologia, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9090, Bairro Agronomia, CEP 90540-000, Porto Alegre, RS, Brazil.
authors.forename: Cláudio W
authors.initials: CW
authors.lastname: Canal
authors.affiliation: Simbios Biotecnologia, Rua Cai, 541, Vila Princesa Izabel, CEP 94940-030, Cachoeirinha, RS, Brazil.
authors.forename: André S K
authors.initials: AS
authors.lastname: Fonseca
authors.affiliation: Laboratório de Diagnóstico Molecular, Universidade Luterana do Brasil (ULBRA), Av. Farroupilha, 8001, Prédio 22, Sala 312, Bairro São José, CEP 92425-900, Canoas, RS, Brazil Simbios Biotecnologia, Rua Cai, 541, Vila Princesa Izabel, CEP 94940-030, Cachoeirinha, RS, Brazil vagner.lunge@gmail.com.
authors.forename: Vagner R
authors.initials: VR
authors.lastname: Lunge
mesh_terms: D000818:Animals; D001938:Brazil / Q000453:epidemiology; D002645:Chickens; D018352:Coronavirus Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D001351:Infectious bronchitis virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D011201:Poultry Diseases / Q000453:epidemiology* / Q000821:virology; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D056189:Viral Tropism
chemical_list: D014764:Viral Proteins
keywords: Brazil; avian; genotype; infectious bronchitis virus; poultry