Pathogenesis of highly pathogenic porcine reproductive and respiratory syndrome virus in Chinese Tibetan swine.
Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) was first characterized in 2006 in China, and it causes great economic losses to the Chinese swine production industry. A China Landrace pig, the Tibetan pig, which has striking phenotypic and physiological differences from lowland pigs, is mainly distributed in the Tibetan highlands of China. The susceptibility of the Tibetan pig to HP-PRRSV has not been reported. In this study, 15 4-week-old Tibetan piglets were divided into three groups, and their susceptibility to HP-PRRSV was examined in the highland region. Five pigs in group 1 were inoculated intranasally with HP-PRRSV strain BB0907. At 2days post-inoculation, five other pigs were introduced into this group and then removed to a separated room to serve as contact group 2. Meanwhile, five pigs in group 3 were mock infected and used as controls. The results showed that the pigs in the inoculated and contact groups showed high fevers and clear clinical signs, including depression, anorexia, lethargy, sticky eye secretions, and hind limb paralysis, with high mortality. The main symptom was interstitial pneumonia. Viremia appeared on days 4 to 14 post-infection. HP-PRRSV infection resulted in inflammatory responses within the first week of infection, as evidenced by the expression of tumor necrosis factor alpha, interleukin (IL)-1β, IL-6, and IL-10. All the data indicate that the Tibetan pig is susceptible to HP-PRRSV infection. Thus, it is necessary to investigate and prevent PRRSV infections in the highland region in China.
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Baochao
B
Fan
Agriculture and animal husband college, Qing Hai University, Xining 810016, China.
Hongjian
H
Zhang
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Juan
J
Bai
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Xing
X
Liu
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Yufeng
Y
Li
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Xianwei
X
Wang
Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address: jiangp@njau.edu.cn.
Ping
P
Jiang
D000281:Administration, Intranasal / Q000662:veterinary; D000818:Animals; D019318:Porcine Reproductive and Respiratory Syndrome / Q000503:physiopathology / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D013552:Swine; D013553:Swine Diseases / Q000503:physiopathology / Q000821:virology*; D018609:Tibet; D014766:Viremia / Q000503:physiopathology / Q000662:veterinary / Q000821:virology
HP-PRRSV; Highly pathogenic; Inflammatory responses; Tibetan swine