An immunohistochemical investigation of porcine epidemic diarrhoea

Abstract

A sudden outbreak of epidemic diarrhoea of piglets occurred in Japan, the principal features being watery diarrhoea, dehydration and high mortality in newborn animals. The microscopical lesions were villous atrophy in the small intestine, the villous enterocytes being vacuolated and cuboidal in shape. The villus-crypt ratio was severely reduced, varying from 1:1 to 3:1. Transmission electron microscopy showed numerous coronaviruses within the cytoplasm of enterocytes and among microvilli. Specific antigens of porcine epidemic diarrhoea (PED) virus were detected in the cytoplasm of enterocytes by the streptavidin-biotin (SAB) technique. Infected cells, which were most abundant in the villous epithelia of the jejunum and ileum, were present in small numbers in the large intestine, the crypt epithelia, the lamina propria and Peyer's patches. The study suggests that the SAB technique is useful for the diagnosis of PED.

Passive Protection against Porcine Epidemic Diarrhea(PED) Virus in Piglets by Colostrum from Immunized Cows.

“…These results indicate that the multiplication of the virus in the small intestine is possibly prevented or reduced by feeding with HCC with high antibody titer. It has been reported that villous atrophy was observed in the jejunum at the onset of clinical signs in two-to three-day old piglets experimentally infected with PED virus [3,4,12], and the length of the villi in these pigs was about 200 to 300 µm [5]. Our results regarding the infected piglets fed UCC in experiment 3 closely resembled these findings.…”

“…In Japan, PED-like disease occurred from late 1982 to early 1983 [6,13]. After that, the disease also occurred between late 1993 and 1996 [12,14]. In 1996, acute outbreaks occurred and more than 39,000 suckling pigs died [14].…”

In Situ Hybridization for the Detection and Localization of Porcine Epidemic Diarrhea Virus in the Intestinal Tissues from Naturally Infected Piglets

“…PEDV antigen has been detected in jejunal and ileal villus enterocytes of swine by monoclonal and polyclonal antibody-based immunohistochemical procedures. 16,21,29 But by using DNA probes and in situ hybridization, there is no possibility for error that could be caused by antigenic cross-reactivity or by the alteration of binding sites caused by tissue processing. Formalin fixation can denature antigens, and this ultimately can lead to falsenegative results.…”

“…Ultrastructural studies have described considerable damage to the villus enterocytes because of infection with PEDV. 13,14,27,29 These changes compromise the digestion and absorption functions of villus enterocytes. Destruction or damage to these cells by PEDV may induce villus atrophy and fusion, which decreases intestinal surface area, resulting in intestinal maldigestion and malabsorption, severe diarrhea, and dehydration.…”

“…2,3,7,23 PEDV antigen has been detected in jejunal and ileal villus enterocytes of swine by monoclonal and polyclonal antibody-based immunohistochemical procedures. 16,21,29 In situ hybridization is a valuable adjunct to standard RNA extraction techniques for evaluating gene expression in tissues and cells. Its major advantage is the ability to determine which tissues, or cells in a mixed population, are expressing the RNA of interest.…”