So sánh đặc điểm lâm sàng của các chủng virus

An investigation was carried out to compare the clinical characteristics of infectious bronchitis virus strains in broiler chickens to have a basis for diagnosis of disease. The broiler chickens that suffered from respiratory problems in Soc Trang Province (10 samples from each flock) were surveyed for symptoms and gross lesions, and results were combined with further testing by RTPCR (Reverse transcription polymerase chain reaction). The results showed that 60.0% of samples were positive to infectious bronchitis virus, in which, 50.0% and 33.3% of positive samples belonged to types 4/91 (793B) and M41 (Massachusetts), respectively, and the remaining positive samples (16.7%) belonged to LX4 (QX). This demonstrated that the infectious bronchitis virus was geneti-