The histopathology of enteric infection with Yersinia pseudotuberculosis.

The gross and microscopic pathologic changes in 70 cases of serologically proven enteric infections with Yersinia pseudotuberculosis are presented. The highest incidence was in young males, and the commonest infecting organism belonged to serologic O-group I. Clinically, the illness resembled acute appendicitis, but the most consistent finding at laparotomy was mesentric lymphadenitis. Surgical specimens examined included 69 mesenteric lymph nodes, 18 appendices, five terminal ileums, and two ascending colons. Histologically, four stages of the disease were identified, leading to the formation of characteristic granulomas with central necrosis and microabscess formation. Ulceration of the intestinal and appendicular mucosa may occur. The illness usually runs a benign course, and antibiotic treatment is rarely necessary. The pathogenesis and differential diagnosis are discussed with reference to the current literature.

Terminal ileitis, mesenteric lymphadenitis and appendicitis due to Yersinia pseudotuberculosis type VA: case report.

A case of terminal ileitis, mesenteric lymphadenitis and appendicitis is reported. Serological studies indicated infection with Yersinia pseudotuberculosis type VA. The patient's illness ran a chronic course necessitating resection of the terminal ileum. Histological examination of the appendix and a mesenteric lymph node in the acute stage revealed granulomas with central necrosis. This is the first human case in which the subtype VA has been identified.

Biochemical, pathogenicity and toxicity studies of type III strains of Yersinia pseudotuberculosis isolated from the cecal contents of pigs.

Recent investigations have shown that the pig is a symptomless intestinal carrier of Y. pseudotuberculosis, the great majority of the strains isolated belonging to type III. Although these type III strains have a world-wide distribution there is little evidence to suggest that they are transferred readily to other animals and man. For that reason we examined the biochemical, pathogenic, immunogenic and exotoxin-producing properties of 24 type III strains isolated from the cecal contents of apparently healthy pigs. For comparison, we also examined type III strains from other sources, type I strains from normal pigs and isolates belonging to the other serotypes of Y. pseudotuberculosis. Biochemical reactions of type III strains were in accordance with data in the literature except for maltose and melibiose. Type III porcine strains were uniformly avirulent and atoxic but possessed a considerable degree of immunogenicity. On the other hand, type III strains isolated from aborted lambs and calves, although atoxic, were virulent for the guinea pig, as were also type I strains from healthy pigs. The pathogenic mechanism of Y.pseudotuberculosis, which is not unlike that found in E. coli, is discussed.

Erythema nodosum due to Pasteurella pseudotuberculosis.

Two children developed erythema nodosum due to Pasteurella pseudotuberculosis. Neither case showed typical signs of P. pseudotuberculosis infection, but this cause was shown by positive agglutination tests. It is suggested that this organism is a more common cause of erythema nodosum than is at present recognized.

Yersinia arthritis: a clinical, immunological, and family study of 2 cases.

We describe 2 patients who presented with yersinia arthritis within a period of 5 months in Leicester. Both were HLA B27 positive. Arthritis followed 2 to 3 weeks after pneumonia, abdominal pain, dysuria, and evidence of hepatic involvement in the first case, and dysuria and conjunctivitis in the second. Immunological studies showed the presence of IgM, IgG, and IgA antibodies at a significant level against Yersinia enterocolitica serotype O:3 in serum and synovial fluid, and immune complexes in the serum of the first case and synovial fluid of both. Arthropathy resolved after 16 weeks in the first case and 12 weeks in the second, the latter requiring systemic corticosteroids. Family studies revealed psoriatic spondylarthritis in the brother, and bilateral sacroiliitis in the mother of the second case. Both were HLA B27 positive. These are the fourth and fifth reported cases of yersinia arthritis in Britain. We believe the condition is probably underdiagnosed and that yersiniosis should be considered as a possibility in otherwise unexplained arthritis.

Enzyme immunoassay of the antibody response to Brucella and Yersinia enterocolitica 09 infections in humans.

An enzyme immunoassay, with phenol-water extracted lipopolysaccharide (LPS) from Brucella abortus as antigen, was used to detect the class-specific antibody response in sera from 173 patients with B. abortus, B. melitensis or B. suis infection. Sera from 30 patients with salmonellosis, yersiniosis or tularaemia and from 25 healthy individuals served as controls. The B. abortus LPS antigen permitted a safe diagnosis of acute and chronic brucellosis with high IgM and rising IgG titres in sera collected in the acute stage of the disease, and with elevated IgG titres only in the chronic stage. The B. abortus LPS antigen also permitted a specific diagnosis with the exception of the high titres estimated in sera from patients with Yersinia enterocolitica 09 infection. The problem with that well-known reciprocal cross-reactivity was overcome by using two additional antigens: Y. enterocolitica 09 native and periodate oxidized and borohydride reduced LPS preparations. In sera from patients with brucellosis high titres were estimated against all three antigens, whereas in sera from patients with yersiniosis caused by serotype 09 high titres were measurable only with the B. abortus and the Y. enterocolitica native LPS antigens. These data suggest that the B. abortus and Y. enterocolitica 09 LPS share one antigenic determinant resistant to periodate oxidation and borohydride reduction, and that in addition the Y. enterocolitica 09 LPS has a determinant which is sensitive to periodate oxidation and borohydride reduction.