Observation on Arthritis in Broiler Breeder
Chickens Experimentally Infected with
Staphylococcus aureus
Chang-qin Gu§,
Xue-ying Hu§, Chang-qing Xie1, Wan-po Zhang,
De-hai Wang, Quan Zhou and Guo-fu
Cheng1*
College of Veterinary Medicine, Huazhong
Agricultural University, Wuhan 430070, PR China; 1MOA Key
Laboratory Food Safety Evaluation, College of Veterinary Medicine,
Huazhong Agricultural University, Wuhan 430070, PR China
*Corresponding author:
chengguofu@mail.hzau.edu.cn
Abstract
Staphylococcus aureus is the most common
cause of bacterial arthritis in broiler breeder chickens. In this study, we
established a model of broiler breeder chicken arthritis inoculated with
Staph.aureus isolated from a spontaneously occurring bacterial arthritis
in chickens. We evaluated the model by bacteriology, serology, pathology, and
immunology. The results showed that 2.5 × 109 cfuStaph.
aureus injected into the right joint cavity can successfully induce a
chicken arthritis model. The majority of the infected chickens suffered lameness
and joint swelling at 3 days post-inoculation (DPI). The death peak time was on
7 DPI and the mortality rate was 51.1%. Staph. aureus can be continuously isolated fromthe blood and left joint synovial fluid of the infected chickens.
Lesions found on the infected chickens consisted of swollen joints full of
caseous exudates, cartilage injury, and synovial membrane thickening with
infiltration of inflammatory cells. The center of the lesion contained many
round bacterial cocci. With joint injury aggravation, intra-articular hyaluronic
acid gradually decreased, and serum interleukin-6 became significantly higher
compared with the control (P<0.01) from 3 DPI. The results indicated that the
chicken models of Staph. aureus-mediated arthritis were successful, and can be used to
gain a better understanding of the host-bacterium relationship.