Antigenic and Pathogenic Characteristics of QX-Type Avian Infectious Bronchitis Virus Strains Isolated in Southwestern China.

The QX-type avian infectious bronchitis virus (IBV) is still a prevalent genotype in Southwestern China. To analyze the antigenicity and pathogenicity characteristics of the dominant genotype strains (QX-type), S1 gene sequence analysis, virus cross-neutralization tests, and pathogenicity test of eight QX-type IBV isolates were conducted. Sequence analysis showed that the nucleotide homology between the eight strains was high, but distantly related to H120 and 4/91 vaccine strains.

A class Ⅰ lentogenic newcastle disease virus strain confers effective protection against the prevalent strains.

The traditional vaccine strains, such as LaSota, do not completely prevent the shedding of NDV. An ideal vaccine which could not only prevent the clinical signs, but significantly reduce the shedding of NDV is urgently needed for the eradication of ND. In this study, an NDV isolate APMV-1/Chicken/China (SC)/PT3/2016 (hereafter referred as PT3) was identified as a class Ⅰ NDV and a lentogenic strain.

Complete Genome Sequence of a Class I Newcastle Disease Virus Strain Isolate from a Breeding Chicken Flock in Sichuan, China.

A Newcastle disease virus (NDV) strain, APMV-1/Chicken/China(SC)/PT3/2016, was isolated from asymptomatic chickens at a breeding farm in China. The PT3 strain has a genome length of 15,198 nucleotides and is classified as subgenotype 1b of class I. Pathogenicity tests demonstrated that PT3 is a lentogenic strain.

Preparation and protective efficacy of a chicken embryo kidney cell-attenuation GI-19/QX-like avian infectious bronchitis virus vaccine.

Avian infectious bronchitis (IB) is a highly contagious disease, and hazardous to the poultry industry. Immune failure often occurs due to the emergence of new serotypes or field strains antigenically different from the vaccine strains. To prepare a candidate vaccine against the prevalent avian infectious bronchitis virus (IBV) in China, the GI-19/QX-like field isolate Sczy3 was selected as the progenitor strain and attenuated via passaging in chicken embryo kidney (CEK) cells for 100 times.

Isolation and molecular characterization of prevalent Fowl adenovirus strains in southwestern China during 2015-2016 for the development of a control strategy.

Fowl adenovirus (FAdV) has caused significant losses in chicken flocks throughout China in recent years. However, the current understanding of the genetic and pathogenic characteristics of the FAdV epidemic in southwestern China remains poorly understood. In this study, a total of 22 strains were isolated from liver samples of diseased chickens from farms in southwestern China.