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Biomedical subjects

M R Wilson

Publications and source records attributed to M R Wilson.

At least 217 records · Page 12Linked to original sources
PubMed1974

Immunity to Escherichia coli in pigs: adhesion of enteropathogenic Escherichia coli to isolated intestinal epithelial cells.

A method was developed to test for the ability of Escherichia coli to adhere to isolated intestinal epithelial cells. Of the E. coli tested, those having either K88ac or K88ab antigens adhered to the cells, and those which did not have these antigens did not. Since some enteropathogenic E. coli did not have the ability to adhere, it is assumed that adherence is not an essential factor of pathogenesis but rather should be considered an enhancement to the pathogenicity of some E. coli. None of the E. coli enteropathogens of cattle tested adhered to either pig or cattle cells. Similarly, human strains did not adhere to pig cells. Although the test system may not have been ideal for human or bovine E. coli, the results reported here suggest that adhesiveness is a property limited to porcine enteropathogenic E. coli carrying one of the K88 antigens. Adhesiveness is associated with the K88c or K88b antigens, and their adhesive ability is only neutralizable by the homologous antisera.

Agglutination Tests↗
PubMed1972

Immunity to Escherichia coli in pigs: serum gamma globulin levels, indirect hemagglutinating antibody titres and bactericidal activity against E. coli in pigs up to five weeks of age.

Serum gamma globulin levels, indirect hemagglutinating antibody titres and bactericidal activity against the 0149:K91;K88ac:H10 Serotype of Escherichia coli were determined in pigs up to five weeks of age from vaccinated and non-vaccinated sows. Gamma globulin levels at two days of age were approximately twice adult levels, by three weeks of age they were one quarter of adult levels and remained so until five weeks of age. Indirect hemagglutinating antibody activity was highest at two days of age, fell until three weeks of age and then rose. Little or no indirect hemagglutinating antibody activity was detected in sera taken at two days of age from pigs from non-vaccinated sows. Only three of 26 two day old pigs had demonstrable bactericidal activity; by three weeks of age 16 of 26 had bactericidal activity. Serum from piglets of vaccinated sows had no more bactericidal activity than did sera from non-vaccinated sows.

Animals↗
PubMed1972

Immunity to Escherichia coli in pigs: antibody secretion by the mammary gland after intramammary or intramuscular vaccination with an E. coli vaccine.

Indirect hemagglutinating antibody titres in individual gland samples of colostrum and milk from 13 sows were measured. Five of the sows were vaccinated via a mammary gland and five by the intramuscular route with a live formalinised Escherichia coli vaccine and three remained as non-vaccinated controls. Antibody titres were higher in colostral and milk whey from the vaccinated sows than from non-vaccinated groups. The inoculated gland in the group of sows given vaccine by the intramammary route secreted milk containing markedly more antibodies to the vaccine E. coli strain than did the non-vaccinated glands. Milk from the vaccinated gland did not contain higher titres to heterologous E. coli O antigens than milk from non-vaccinated glands. Serum titres were the same or higher than the titres in colostrum from non-vaccinated glands.

Animals↗
PubMed1971

Immunity to Escherichia coli in pigs. The role of milk in protective immunity to e. coli enteritis.

Milk whey from immunized sows increased the survival time of gnotobiotic piglets infected with Escherichia coli. The survival time of infected piglets fed milk whey from non-vaccinated sow's was the same as that of similar pigs fed condensed cow milk. The significance of milk antibodies in immune protection against E. coli enteritis is discussed and compared with that of absorbed colostral antibodies. From calculations presented it would appear that seven day old piglets receive approximately 1 g of gamma globulin daily from milk and that this is equal to the piglets total serum gamma globulin content. After seven days of age the gamma globulin content of piglet serum falls, whereas that of milk remains constant; milk is, therefore, potentially a major source of immunoglobulins with protective activity against E. coli associated enteritides.

Animals↗
PubMed1971

Immunity to Escherichia coli in pigs: anti-enterotoxins in colostrum and serum from vaccinated and non-vaccinated sows.

Colostrum from non-vaccinated sows did not contain naturally occurring antibodies to heat labile Escherichia coli enterotoxin. Vaccination of sows by either the intramuscular or intramammary routes with a live formalinized E. coli vaccine resulted in the production of colostrum capable of neutralizing the heat labile toxin. Intramammary vaccination resulted in the production of colostrum which significantly reduced the enterotoxigenic effects of the vaccine strain of E. coli organisms but not that of a heterologous strain. Vaccination of the sows resulted in the production of serum antibodies to heat labile enterotoxin. Antibodies to heat stable enterotoxin were not demonstrable in the colostrum of either non-vaccinated or vaccinated sows.

Animals↗