Biomedical subjects

E G Harry

Publications and source records attributed to E G Harry.

At least 19 recordsLinked to original sources

PubMed1979

Increase in resistance to acute experimental coli-septicaemia in chicks given high levels of ferrous sulphate in the diet.

The resistance of chicks to coli-septicaemia following injection of approximately 10(8) cells of Escherichia coli O78 was found to be appreciably increased in terms of mortality by the supplementation of their diet with 360 mg/kg or more of iron in the form of commercial hydrated ferrous sulphate. This was related to an increase in the plasma iron levels. The results suggest that increased resistance to infection could be partly achieved by correcting the hypoferraemia which has previously been shown to be produced in chickens by injections of E coli endotoxin lipopolysaccharide (LPS). The results also showed that haematological disturbances in survivors of coli-septicaemia can persist for up to at least 30 days after infection.

Administration, Oral↗

PubMed1979

Laboratory and field trials on a formalin inactivated vaccine for the control of Pasteurella anatipestifer septicaemia in ducks.

A series of laboratory trials on a number of different types of inactivated Pasteurella anatipestifer vaccines suggested that a formolised vaccine would be the most suitable for protection. A satisfactory dose of vaccine was found to be approximately 3 x 109 cells administered intramuscularly. The efficacy of this vaccine was confirmed by a field trial on a farm where anatipestifer septicaemia was endemic, ducks being vaccinated at three weeks of age before their transfer to pasture from indoor rearing units.

Animals↗

PubMed1978

Laboratory trials with inactivated vaccines against Escherichia coli (O2:K1) infection in fowls.

Laboratory trials were carried out with an O2:K1 vaccine prepared with either the Freund's complete or incomplete adjuvant. Both types of vaccine administered subcutaneously were highly effective against a challenge with the vaccine strain within three to four weeks after vaccination at two to three weeks of age. The complete adjuvant vaccine was more effective than the incomplete adjuvant vaccine when administered to chickens of an earlier age, and in the rate of development and duration of immunity. The efficacy of both vaccines was unimpaired by their incorporation with the Newcastle disease oil adjuvant (inactivated) vaccine (Newcadin). The use of an oil adjuvant vaccine was not found to affect the rate of growth adversely or to produce any other reaction prejudicial to its commerical application. The efficacy of the vaccines was unimpaired by their incorporation with Newcastle disease oil adjuvant (inactivated) vaccine (Newcadin) thus demonstrating the possibility of producing a combined Escherichia coli/Newcastle disease virus vaccine.

Age Factors↗

PubMed1977

Evaluation of methods for the determination of Q and K antigens of an 02:K1(L) strain of Escherichia coli.

Tests made on ten colonies from a strain of Escherichia coli O2:K1 demonstrated that bacterial agglutination tests were reliable for identifying the O antigen of serogroup O2 but were unreliable for identifying the K1 antigen. The granular nature of K agglutination was not a reliable characteristic of the L type of K antigen. In contrast, indirect haemagglutination, immunodiffusion and immunoelectrophoresis tests with bacterial extracts gave consistent results with all colonies. The polysaccharide K1 antigen formed a long anodic precipitation line with two peaks, indicating its heterogenous nature, and partial fusion of this line with the O-antigen precipitation line suggested the presence of common serological determinants. In addition, a heat-labile protein antigen, possibly another K antigen, was identified by indirect haemagglutination tests and may have produced a short anodic precipitation line. The results also showed that the K1 antigen was still produced after storage of a culture for 12 years on Dorset-egg medium.

Agglutination Tests↗

PubMed1977

Escherichia coli endotoxin as a stressor in the domestic fowl.

During 24 h after the injection of fowls (aged eight to 11 weeks) with Escherichia coli endotoxin (1 to 3 mg/kg) isolated from a pathogenic strain (O78) there were changes in the ascorbate content of the adrenal gland and increases in the plasma free fatty acid levels, indicating that the toxin behaves as a mild stressor.

Adrenal Glands↗

PubMed1977

The effect of Escherichia coli endotoxin on lysosomal enzymes in the domestic fowl.

During the 2 h following the injection of chickens (aged nine to 11 weeks) with endotoxin isolated from a pathogenic strain of Escherichia coli (O78) there was a transient rise in the activity of acid phosphatase, aryl sulphatase and beta-glucuronidase in the plasma, suggesting increased release of these enzymes from lysosomes. This was followed by a fall in their activity which may have been due largely to stabilisation of the lysosomal membrane brought about by increased secretion of adrenocortical hormones and/or accelerated removal of the enzymes from circulation by the reticuloendothelial system.

Acid Phosphatase↗

PubMed1976

The effect of orally administered histamine on the weight gain and development of gizzard lesions in chicks.

The results of a large scale trial confirmed preliminary findings that the feeding to chicks of a diet containing 4 mg/g of histamine can result in the production of localised lesions in the gizzard and depressed growth rate. This finding supports an earlier suggestion that when dietary fish meal is associated with gizzard erosion the condition is mediated, in part, by the histamine produced by certain types of bacterial spoilage of fish protein.

Administration, Oral↗

PubMed1976

Laboratory trials with inactivated vaccines against Escherichia coli (O78 K80) infection in fowls.

Laboratory trials made with five inactivated (O78 K80) Escherichia coli vaccines showed that the greatest degree of protection against an intramuscular challenge with the homologous strain was obtained with an alum precipitated vaccine. This vaccine was equally effective when administered by the subcutaneous, intramuscular or intraperitoneal route. Maximal protection, persisting for at least six weeks, was obtained by inoculating chicks at three weeks of age with a dose of approximately 1-5 X 10(9) cells in 0.5 ml. Some degree of protection was obtained, however, in chicks vaccinated earlier. There was no evidence that this vaccine provided any cross protection against other pathogenic serotypes of E coli. No adverse effect was noted on growth rate or carcase quality in the chicks vaccinated. Immunological studies showed that protection was not related to the production of O and K serum agglutinins.

Age Factors↗

PubMed1975

The role of histamine and fish meal in the incidence of gizzard erosion and pro-ventricular abnormalities in the fowl.

The role of certain fish meals in the production of localised gizzard erosion is confirmed. Lesions typical of gizzard erosion could be produced by the addition of histamine to the diet. The amount of histamine occurring naturally in fish meal depends on the species of fish and the extent and nature of bacterial spoilage. These variables may explain why histamine has not been implicated previously and also why there have not been consistent associations between the condition and geographical source or common factors in bulk consignments of the meal.

Animal Feed↗

PubMed1973