The pathophysiology of astrovirus infection in hatchling turkeys

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" The pathophysiology of astrovirus infection in hatchling turkeys "
M. L. Thouvenelle J. S. K. J. P. Haynes

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	1104053
Doc. No	:	TLpq303983084
Main Entry	:	J. S. K. J. P. Haynes
	:	M. L. Thouvenelle
Title & Author	:	The pathophysiology of astrovirus infection in hatchling turkeys\ M. L. ThouvenelleJ. S. K. J. P. Haynes
College	:	Iowa State University
Date	:	1992
student score	:	1992
Degree	:	Ph.D.
Page No	:	145-145 p.
Abstract	:	Experiments were conducted to determine the effect of astrovirus infection in hatchling turkeys. Additionally, the lectin-binding affinities of the small intestinal glycocalyx were investigated by direct biotin-strep-avidin technique in poults. Two to 5 day old poults were inoculated orally with astrovirus. Poults were examined on days 0.5 to 14 post inoculation (PI). Histopathological changes were documented by computerized image analysis, localization of virus was accomplished by transmission electron microscopy, and specific maltase activity was determined by intestinal disaccharidase analysis. Poults on days 2 through 10 post inoculation (PI) had diarrhea, generalized loss of intestinal tone and dilatated ceca containing fluid to semi-solid feces and gas. Progressive mild crypt hyperplasia was noted 1 day PI in the proximal jejunum and by day 3 in the distal jejunum and ileum. The duodenum was affected on days 5 and 7 PI. Significant (P <.05) increases in crypt depth and area in the distal jejunum and ileum were documented by image analysis on day 3 PI. The majority of the small intestine was affected seven days after inoculation. Intracytoplasmic crystalline arrays of astrovirus were found in the ileal villous enterocytes on days 2 and 3 PI, but only on day 3 in the distal jejunum. Specific maltase activity (SMA) was decreased (P <.05) in the entire small intestine of inoculated poults 3 to 7 days PI. On day 10 PI, no significant difference (P >.05) was detected in SMA levels in inoculated versus control poults. However by day 14 PI, SMA levels were increased in all sections of the small intestine of inoculated poults, except the proximal jejunum. There was no definitive staining of the glycocalyx with any of the 15 lectins evaluated, irrespective of regional location or age. Experimental astrovirus produced typical clinical signs and gross lesions associated with enteric disease. Only subtle histopathological changes were noted, however significant and consistent morphometric changes were documented. Astrovirus appeared to replicate in villous enterocytes of the distal small intestine. Maldigestion was the primary pathogenic effect in the small intestine. The small intestine of young poults does not have a definitive histochemical lectin-binding pattern based on this study.
Subject	:	Animal diseases
	:	Biological sciences
	:	turkeys
	:	Veterinary services