The role of porcine teschovirus in causing diseases in endemically infected pigs

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• 作者：Shu-Chun Chiu^a ; ^b ; Shu-Chia Hu^a ; ^b ; Chih-Cheng Chang^c ; Chia-Yi Chang^a ; Chin-Cheng Huang^a ; Victor F. Pang^b ; Fun-In Wang^b ; ^{fiwangvm@ntu.edu.tw}
• 关键词：Porcine teschovirus ; Endemic ; Multi-infection ; Nonsuppurative encephalitis
• 刊名：Veterinary Microbiology
• 出版年：2012
• 出版时间：28 December, 2012
• 年：2012
• 卷：161
• 期：1-2
• 页码：88-95
• 全文大小：417 K

文摘

Porcine teschoviruses (PTVs) belong to the genus Teschovirus within the family Picornaviridae. Hitherto, PTVs have had 13 serotypes associated with a variety of clinical diseases. The virulent PTV-1 strains were associated with highly fatal, nonsuppurative encephalomyelitis of pigs (Teschen disease) in the 1930-1950s. Today, less virulent Talfan strains of PTV-1 are more widespread, and PTVs have contaminated swine herds worldwide (endemic or enzootic) together with a variety of common swine pathogens (multi-infection status). The aim of this study was to investigate the extent to which PTVs play a role in causing diseases in the field, under the endemic and multi-infection situation, when most pigs in the herds are infected and immune. Based on the fecal-oral model of pathogenesis, a set of 15 organs were collected from 30 culled post-weanling piglets of 4-8 weeks old. For nested RT-PCR targeted on the 5¡ä-NTR, the PTV detection rate was 96.7 % (by heads), confirming the endemic status, and infection was most commonly detected in the intestines (averaged 61 % ) and lymphoid organs (averaged 59 % ), followed by visceral organs (averaged 37 % ) and the CNS (different parts varied from 17 to 47 % ). The correlation of PTVs detected by nested RT-PCR and a histological lesion were analyzed by Chi-square test showing that in the field situation only non-suppurative encephalitis in the caudal part of the brain (P = 0.054) may be marginal significantly attributed to infection by PTVs. By genotyping based on partial VP1 sequences, 5 serotypes, namely PTV-1, -4, -6, -7, and -11, were identified, with some animals having two serotypes co-existed in different organs.