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Biomedical subjects

J M Rutter

Publications and source records attributed to J M Rutter.

54 records · Page 3Linked to original sources
PubMed1975

Adhesion of enteropathogenic Escherichia coli to pig intestinal brush borders: the existence of two pig phenotypes.

An in-vitro test that demonstrates adhesion of K88-positive Escherichia coli to brush borders prepared from the small intestine of the pig is described. K88-positive E. coli adhered to the brush borders from some pigs ("positive" pigs) but not others ("negative" pigs). The sires of the pigs tested could be placed into two groups, namely, those that sired only "positive" piglets, and those that sired a mixture of "positive" and "negative" piglets. The incidence of the two phenotypes in litters indicated that "positive" and "negative" piglets arose as a result of simple Mendelian inheritance. It is suggested that "negative" pigs could be bred and that they might have a natural resistance to neonatal infection with K88-positive E. coli.

Animals↗
PubMed1975

Synergism between Trichuris suis and the microbial flora of the large intestine causing dysentery in pigs.

The role of the microbial flora of the large intestine in experimental Trichuris suis infection was studied by comparing the clinical syndrome in conventionally reared (CR) pigs, specific pathogen-free pigs, and gnotobiotic pigs. Thedisease in CR pigs was characterized by a severe mucohemorrhagic enteritis; in contrast, a mild catarrhal enteritis was observed in specific pathogen-free and gnotobiotic pigs. Spirochaetes and vibrio-like organisms were observed only in CR pigs and increased during the clinical phase of the disease. The clinical syndrome was not transmitted by oral administration of intestinal or fecal material from infected CR pigs to CR pigs free of T. suis. Smaller numbers of T. suis produced diarrhea in CR pigs and significantly reduced the growth rates of infected animals; clinical signs and the reduction in growth rate was prevented by incorporating an antibacterial substance (dimetridazole) in the food. Although clinical trichuriasis closely resembles swin dysentery, the two syndromes seem to be distinct. The present results suggest that a microbial component acts synergistically with T. suis to produce the severe clinical syndrome in CR pigs, but identification of the microbial component and the mechanism by which clinical signs are produced await further studies of the bacterial flora of the large intestine of pigs.

Animals↗
PubMed1972

Role of the K88 antigen in the pathogenesis of neonatal diarrhea caused by Escherichia coli in piglets.

The role of the K88 antigen of Escherichia coli in neonatal diarrhea of piglets was studied by comparing a K88-positive strain with three K88-negative strains derived from the K88-positive strain. K88 antigen was produced by the K88-positive strain in the intestinal tract of gnotobiotic piglets, whereas K88-negative strains did not regain the ability to synthesize K88 antigen. Synthesis of the antigen conferred different colonization characteristics on the four strains; K88-positive bacteria adhered to the mucosa of the small intestine, whereas K88-negative bacteria did not attach and were distributed throughout the lumen. Adhesion of K88-positive bacteria to tissue from the small intestine of gnotobiotic piglets was demonstrated in vitro and was inhibited by antisera that contained K88 antibodies. Attachment did not occur with bacteria grown at 18 C. Adhesion of cell-free K88 antigen was also demonstrated. The K88-positive strain and one of the K88-negative strains were equally virulent in gnotobiotic piglets. In contrast, the K88-positive strain killed 50% of conventionally reared piglets, whereas the K88-negative strain killed only 3%. Adhesion of the K88-positive strain, but not of the K88-negative strain, to the mucosa of the small intestine was demonstrated. Our results show that K88 antigen is responsible for attachment of K88-positive bacteria to the wall of the small intestine, and that adhesion is essential for the virulence of K88-positive bacteria in conventionally reared piglets.

Agglutination Tests↗