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.
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.
Poult Sci. 2014 Aug;93(8):1922-9. doi: 10.3382/ps.2014-03875. Epub 2014 Jun 3.
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.
鸡传染性支气管炎是一种具有高度传染性的病毒性疾病，对家禽养殖业有经济影响。该疾病表现出多系统临床症状（呼吸、肾脏、肠道和生殖），由一种冠状病毒（传染性支气管炎病毒，IBV）引起。传染性支气管炎病毒分为不同的血清型和基因型（疫苗株和田间变异株）。本研究旨在评估巴西 3 个重要生产地区商业家禽群中 IBV 的发生情况，并确定主要循环基因型对 3 个不同禽生理系统（呼吸、消化、泌尿/生殖）的趋向性。从 432 个不同的商业家禽群中收集了具有 IBV 感染提示迹象的临床样本（198 个来自肉鸡，234 个来自种鸡）。总共有来自 3 个重要生产地区的农场的 3 个生理系统的器官池组成的生物样本。通过 5'非翻译区的逆转录实时 PCR 检测传染性支气管炎病毒。结果显示，179 个 IBV 阳性群（41.4%的群），其中 107 个（24.8%）来自肉鸡，72 个（16.8%）来自种鸡。来自该国不同地区的农场中 IBV 阳性群的频率相似，肉鸡中（平均 54%）比种鸡中（平均 30.8%）更为常见。在种鸡的消化系统中更频繁地检测到逆转录，在肉鸡的消化系统（43.5%）和呼吸系统（37.7%）中也更频繁地检测到逆转录。通过从 79 个 IBV 阳性群（45 个来自肉鸡，34 个来自种鸡）中选择的 S1 基因的逆转录巢式 PCR 和测序进行 IBV 基因分型。大多数鸡群感染的是巴西变异株基因型，而不是马萨诸塞州疫苗株基因型。这些结果表明，巴西变异株（主要在肠道）在巴西 3 个重要生产地区的商业家禽群中占主导地位。
