Localization of Spirochetes with the Structural Characteristics of Treponema hyodysenteriae in the Lesions of Swine Dysentery

Abstract

The large intestines of pigs with swine dysentery were examined by phase, light, and electron microscopy at intervals up to 11 days after oral inoculation with mucosal scrapings from infected pigs. Large spirochetes with the structural characteristics of Treponema hyodysenteriae were found only in infected pigs and were first observed in small numbers in the lumen of the large intestine 2 days after inoculation. Numerous large spirochetes were present on the luminal surface and in mucosal crypts as lesions developed. Degenerative changes were first observed in the apical portion of epithelial cells in close contact with large spirochetes. These large spirochetes were found intact in goblet cells and epithelial cells in the early stages of the disease and were numerous within degenerating epithelial cells as lesions became more advanced. Invasion beyond the lamina propria was not detected. These observations demonstrated the relationship between pathogenic large spirochetes and the mucosa of the large intestine in a specific disease, swine dysentery.

Consecutive pathological and immunological alterations during experimentally induced swine dysentery – A study performed by repeated endoscopy and biopsy samplings through an intestinal cannula

“…The depletion of mucus from the goblet cells in the basal part of the crypts is commonly reported (Lysons et al, 1984;Pohlenz et al, 1983;Wilcock and Olander, 1979), however, it is unclear whether this results from an increased expulsion of mucus or by diminished mucigen formation in immature proliferating goblet cells (Wilcock and Olander, 1979). Goblet cell hyperplasia and mucus hypersecretion was prominent in later stages, as also reported by Lysons et al (1984) but in contrast to Glock et al (1974), who regarded this as pronounced feature of the early course of the disease. In the present study, the overall cellularity of the lamina propria did not appear to be altered.…”

“…Others report that the severity of the lesions does not increase with duration of the disease (Wilcock and Olander, 1979). Crypt hyperplasia is a consistent feature of the disease (Glock et al, 1974;Wilcock and Olander, 1979). In the present study, it seemed that crypt hyperplasia was more marked after a few days of diarrhoea and goblet cell hyperplasia became prominent on the fifth and seventh day after the development of diarrhoea.…”

“…The lesions in pigs with a moderately to severely depressed condition did not differ macroscopically from lesions in pigs with slightly depressed general behaviour. When viewed by light microscopy, the lesions have been reported to progress from catarrhal to fibrinonecrotic enteritis as the disease progresses (Glock et al, 1974). Others report that the severity of the lesions does not increase with duration of the disease (Wilcock and Olander, 1979).…”

Isolation, Oxygen Sensitivity, and Virulence of NADH Oxidase Mutants of the Anaerobic Spirochete Brachyspira ( Serpulina ) hyodysenteriae , Etiologic Agent of Swine Dysentery

“…Brachyspira (Serpulina) hyodysenteriae cells colonize the oxygen-respiring mucosal tissues of the swine cecum and colon. During the early stages of swine dysentery, cells of this spirochete are visible first along the intestinal epithelium and then among epithelial cells and within goblet cells (7,20). As the disease progresses, lesions appear in the mucosa at sites of spirochete colonization and host blood passes from underlying capillaries into the intestinal lumen through the lesions (7,17).…”

“…During the early stages of swine dysentery, cells of this spirochete are visible first along the intestinal epithelium and then among epithelial cells and within goblet cells (7,20). As the disease progresses, lesions appear in the mucosa at sites of spirochete colonization and host blood passes from underlying capillaries into the intestinal lumen through the lesions (7,17). For the most part, bacterial characteristics essential for B. hyodysenteriae colonization and pathogenesis have not been thoroughly investigated, although there is evidence that hemolytic activity (15,48) and bacterial motility and chemotaxis (18,26,32) are important contributing factors.…”