XÁC ĐỊNH, PHÂN NHÓM VIRUS GÂY BỆNH VIÊM PHẾ QUẢN TRUYỀN NHIỄM TRÊN GÀ NĂM 2018 Ở ĐỒNG BẰNG SÔNG CỬU LONG

Abstract

There were 8 nucleotide sequences of the nucleoprotein gene (N) including 403 bp collected from 7 IBV specimens on the chickens raising in Soc Trang and Vinh Long provinces identified by PCR and sequencing. The nucleotide sequences of gene N of IBV were arranged and compared. The pedigree of 25 strains was analyzed and genetic distance of 20 strains was calculated. The studied result showed that among 8 IBV strains isolated in Viet Nam, some strain groups presented a very low genetic distance, for example: 0-0.2% among 3 strains (IBST3, IBST4, IBST9), 0.5% between 2 strains (IBST5-1, IBST5-2) and 0% between 2 strains (IBST14 and IBVL22). Base on pedigree analysis, 25 IBV strains were divided into 2 groups, including: Group 1 consisted of all IBV strains in the world, 3 IBV strains isolated in 2018 at Soc Trang (IBST4, IBST3, IBST9), vaccine strain 4-91 (KF377577), and 2 strains (IBST5-1, IBST5-2) together with Mass 41 (AY851295). Group 2: consisted of all the Chinese IBV strains and 2 strains isolated in Vinh Long (IBVL17, IBVL22) and 1 strain isolated in Soc Trang (IBST14) together with QX and LX4 (QX-like) strains of China. At least, there were 3 IBV strains determined to be infected on the chicken herds, presenting co-infection in the same chicken. Of which, there were group 4-91, Mass (Mass41) and QX (LX4 or QX-like) isolated in 2018 in Soc Trang and Vinh Long.