Polioencephalomyelitis in Pigs Experimentally Infected with Porcine Enterovirus Isolated in Korea: I. Histopathological Observations

Enterovirus 감염에 의한 자돈의 Polioencephalomyelit: I. 병리조직학적 관찰

  • Shin, Tae-kyun (Department of Anatomy, College of Medicine, Chungnam National University) ;
  • Lee, Cha-soo (Department of Veterinary Medicine, College of Agriculture, Kyungbuk National University)
  • 신태균 (충남대학교 의과대학 해부학교실) ;
  • 이차수 (경북대학교 농과대학 수의학과)
  • Received : 1985.09.05
  • Published : 1985.10.20

Abstract

A total of 1-0 colostrum-deprived pigs (1 or 2-day-old) and 6 pigs (35-day-old), which had been raised by natural maternal nursing, were used to study the pathogenicity of the porcine enteroviruses by the intracerebral and intramuscular routes of inoculation, which the enterovirus were isolated from the diseased pigs in Korea. The porcine enteroviruses produced an identical polioencephalomyelitis in colostrum-deprived pigs and 35-day-old pigs, which manifested clinical signs and histopathological changes. Clinically it was characterized by incoordination, rise in rectal temperature, ataxia, flaccid paralysis in all the experimental groups. Histopathologically, the lesions were present in both grey and white matter at all levels of central nervous system, though usually more severe in the grey matter. These changes were characterized by meningeal infiltration, degeneration of nerve cells, neuronophagia, diffuse and focal gliosis, glial nodules and perivascular lymphocytic infiltrations. Ganglionitis of the dorsal root ganglia was frequently observed. On the basis of the clinical and histopathological changes mentioned above, it was concluded that porcine enteroviruses isolated in Korea were pathogenic strains which could produce polioencephalomyelitis in pigs. The most severe Jisease was prcduced by the inoculation of both enterovirus and hog cholera vaccine in the 35-day-old pigs at a time when colostral immunity presumably was low. The porcine enterovirus infections seemed to be associated with certain stress factor such as hog cholera vaccine in or immediately following the weanling period.

국내에서 분리된 enterovirus의 병원성을 관찰하기 위하여 1~2일령의 자돈 10두와 35일 령의 유돈 6두에 enterovirus 조직배양부유액을 뇌내 또는 근육내 주사한 후 임상 및 병리학적으로 관찰하였던 바 다음과 같은 결과를 얻었다. 임상적으로는 체온의 상승, 보양창랑, 보행실조, 유약성 마비 및 고도의 삭수가 관찰되었다. 병리조직학적으로는 중추신경계 전반에 걸쳐 수막하 세포침윤, 혈관주위 원형세포침윤, 신경세포의 변성, 미만성과 한국성 gliosis, glial nodule의 형성 등이 관찰되었으며 백질부보다 회백질부에서 다소 심한 경향이었고 배측 신경절염이 전 실험예에서 인정되었다. 한편 hog cholera백신과 enterovirus의 공동주사예에서는 중추신경계의 병변이 enterovirus 단독주사예에 비해 급격히 진행되는 경향이었다. 이상의 소견들을 종합해 볼때 국내에서 분리된 enterovirus는 뇌내 또는 근육내에 접종하였을 때 자돈에서 polioencephalomyelitis를 일으킬 수 있는 병원성이 강한 형으로 추측되며 hog cholera백신과 enterovirus를 공동주사한 예에서 병변의 진행이 급격한 점으로 보아 enterovirus의 자연감염에 hog cholera 백신 등의 stress요인이 작용될 것으로 추측된다.

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