Ultrastructural changes in the small intestinal epithelium of suckling pigs affected with a transmissible gastroenteritis (TGE)-like disease

Abstract

The small intestine of piglets collected during a sudden outbreak of diarrhoeal disease resembling transmissible gastroenteritis (TGE) was examined by light and electron microscopy. The principal histopathological changes were moderate infiltration by mononuclear cells in the lamina propria of the villi and cytoplasmic vacuolation. These were most pronounced in the epithelial cells covering the villous tips. By scanning electron microscopy, the intestinal villi were swollen and the transverse furrows disappeared. Microvilli were reduced in number leaving denuded areas on the brush border of the villous epithelial cells. The ultrastructural changes were restricted to the cytoplasm of affected villous epithelial cells. The cell organelles were missing in rounded areas leaving cleared areas in the cytoplasm. Parallel fascicles and bundles were seen in these areas. Viral particles with an average diameter of 70 nm were found within the dilated apical tubulo-vesicular system, free in the cytoplasm, among the microvilli, or lying free in the intestinal lumen. Viral particles surrounded a non-membrane bound viroplasm in some cases. The negatively stained particles showed a typical coronavirus morphology. These particles were found to be distinct from the known coronaviruses of swine, TGE virus and hemagglutinating encephalomyelitis virus by immune electron microscopy.

Genetic evolution analysis and pathogenicity assessment of porcine epidemic diarrhea virus strains circulating in part of China during 2011–2017

“…PEDV infects pigs of all ages, especially the newborn piglets, causing severe acute watery diarrhea, vomiting and dehydration with the morbidity of up to 100% (Coussement et al, 1982;Shibata et al, 2000;Wood, 1977). The highly contagious enteric disease of swine associated with PEDV was first reported in England in 1971 and then it spread to another 13 countries of Europe and Asia (Ben Salem et al, 2010;Horvath and Mocsari, 1981;Kusanagi et al, 1992;Martelli et al, 2008;Pensaert and de Bouck, 1978;Pijpers et al, 1993;Pospischil et al, 1981;Smid et al, 1993;Takahashi et al, 1983).…”

An inactivated vaccine made from a U.S. field isolate of porcine epidemic disease virus is immunogenic in pigs as demonstrated by a dose-titration

“…Porcine epidemic diarrhea virus (PEDV) circulated throughout Europe and Asia during the past three decades before being detected in swine in the United States in May, 2013 [1][2][3][4][5][6][7]. Since its introduction to the U.S., PEDV has been identified in 33 states by the National Animal Health Laboratory Network, as of December, 2014 (www.aasv.org).…”

Expression of a Cholera Toxin B Subunit-Neutralizing Epitope of the Porcine Epidemic Diarrhea Virus Fusion Gene in Transgenic Lettuce (Lactuca sativa L.)

“…PEDV has been classified as a member of the Coronaviridae family [1,2]. PED was first detected in Belgium [3] and the UK [4] in 1978, and outbreaks of this disease have been reported in many pig farming countries, leading to severe economic losses in Canada [5], Europe [6,7], and Asia, including Japan [8], China [9], Korea [10], and more recently, Thailand [11]. The complete sequence of the entire genome of the strain CV777 was found to be 28,033 nucleotides in length, after excluding the poly(A) tail [12,13].…”