Pathogenicity of human and porcine intestinal spirochetes in one-day-old specific-pathogen-free chicks: an animal model of intestinal spirochetosis

Abstract

One-day-old chicks were infected orally with two strains of weakly hemolytic spirochetes isolated from a human and a pig with intestinal spirochetosis. These spirochetes both colonized birds, attached end-on to their cecal enterocytes, induced watery diarrhea, and significantly depressed growth rates. Cultures of Serpulina innocens failed to colonize the chicks.

Infective colitis associated with human intestinal spirochetosis

“…In the literature, the same histological features described for human IS were found in animal models of human IS (weaned pigs, 1-day-old chicks) and in cases of spirochetosis in pigs, dogs and poultry. 8,31 Concerning the histological aspects of human IS described in the literature, our results confirmed the role of histology in recovering spirochetes and in the description of the possible pathogenicity of the microorganisms, because in all cases we reported that active colitis was evident. In accordance with other reports in the literature, 4,12,13,29,30,35 our study suggested a possible pathogenetic mechanism based on the extension of Brachyspira presence in all segments of the colon, evidence of the progressive destruction of microvilli with direct contact between the bacteria and the cell membrane, and presence of colitis with inflammatory infiltrate and sometimes cryptitis.…”

“…This was associated with various symptoms and has since then been described by many authors. [1][2][3][4][5][6][7][8][9][10][11][12]24,[29][30][31][32] Since 1997, Brachyspira spp. has been included in the list of human enteropathogenic bacteria.…”

Genetic relatedness amongst intestinal spirochaetes isolated from rate and brids.

“…Similar colonization has been reported for human and porcine strains of S. pilosicolz in naturally occurring cases of IS, and in experimental infections of 1-d-old SPF chicks (Dwars et nl. 1992a;Trott et al 1995). Strains of S. pilosicoli therefore infect wild birds and potentially may be a source of infection to other species, including humans.…”

Intestinal spirochetosis and chronic watery diarrhea: Clinical and histological response to treatment and long‐term follow up

“…11 There also have been studies in which intestinal spirochete strains isolated from humans have been used to infect and cause intestinal disease in chickens and pigs. 12,13 In contrast, in studies where colonic specimens or feces of a large series of patients were assessed, IS was a frequent finding, ranging from 1.9 to 50%, 3,10,11,[14][15][16][17] being particularly common in developing communities. 3,10,11,18,19 In some studies symptoms were not modified by IS eradication, [14][15][16][17] leading to the suggestion that intestinal spirochetes are harmless commensals in humans, and thus specific treatment is not required.…”