Search PubMed⌕ Search

Biomedical subjects

J F Prescott

Publications and source records attributed to J F Prescott.

138 records · Page 8Linked to original sources

Cellular and humoral immune response of foals to vaccination with Corynebacterium equi.

Transformation of peripheral blood lymphocytes from pony foals vaccinated and subsequently infected with Corynebacterium equi was studied. Three foals were vaccinated on two occasions using a formalinized C. equi vaccine with aluminum hydroxide as an adjuvant. Three nonvaccinated foals served as controls. Foals were challenged intratracheally with 9 x 10(9) C. equi six weeks after the initial vaccination. Foals survived this infection for one to two weeks. Significant lymphocyte transformation in response to C. equi antigens was detected in two vaccinated foals at the third week after initial vaccination and in all vaccinated animals at the fifth week. No statistically significant transformation was seen in nonvaccinated foals before infection. Vaccinated and nonvaccinated foals showed responsive lymphocytes following challenge. Vaccination offered no obvious protection against experimental challenge but this failure was probably due to an excessive infective dose of organisms. Low levels of humoral antibodies were detected in some challenged foals. The pathological changes in the lungs of infected animals were comparable with, but more fulminating than, changes observed in the natural disease.

Animals↗

Haemorrhagic gastroenteritis in the dog associated with Clostridium welchii.

Two cases of peracute haemorrhagic enteritis in the dog are reported. Gram-positive bacilli, which were shown in one case to be Clostridium welchii were found adhering to the necrotic epithelial surfaces in parts of the gastrointestinal tract in both cases. Large numbers of C welchii were recovered from the intestines of both dogs.

Animals↗

Escherichia coli and diarrhoea in the rabbit.

An outbreak of severe diarrhoea and death in young rabbits was associated with many nonenterotoxigenic Escherichia coli in the caecum. The severe clinical, pathological and bacteriological features of the diesase, acute diarrhoea associated with typhlitis and many E. coli in the caecum, could be reproduced either by the intraintestinal inoculation of many bacteria recovered aerobically or anaerobically from the caecum of these rabbits or by the intestinal inoculation of large numbers of a serogroup of E. coli, 0153, recovered from the caecum. Further experiments showed that this serogroup of E. coli, as well as a nonenteropathogenic serotype recovered from human faeces, would cause typhlitis and diarrhoea if inoculated in large numbers into the jejunum; pathological changes also were seen in the liver and kidney. Similar changes also could be induced by intravenous inoculation of a freeze-thaw (endotoxic) extract prepared from these strains. Any factor that allows rapid multiplication of E. coli in the rabbit caecum may be followed by absorption of endotoxin and subsequent typhlitis and so metimes by severe diarrhoea; this effect is seen in some field cases of diarrhoea in the rabbit.

Animals↗

Tyzzer's disease in rabbits in Britain.

Tyzzer's disease seems to be a not uncommon cause of diarrhoea in rabbits in Britain. It may occur either epizootically or enzootically in affected rabbit units. The more acute form may present difficulties in diagnosis.

Animals↗

Swine dysentery: protection of pigs by oral and parenteral immunisation with attenuated Treponema hyodysenteriae.

An attenuated strain of Treponema hyodysenteriae was used to immunise 18 pigs in three experiments. Live attenuated spirochaetes were dosed orally and injected intra-peritoneally, and killed spirochaetes were injected intramuscularly with adjuvant. The vaccinated pigs, which developed high serum agglutination titres against T hyodysenteriae, and 18 unvaccinated litter-mates were repeatedly challenged with virulent T hyodysenteriae. Nine vaccinated pigs and 16 control pigs developed typical swine dysentery.

Agglutination Tests↗

The effect of occlusive and semi-occlusive dressings on the healing of acute full-thickness skin wounds on the forelimbs of dogs.

This project compared the effects of hydrocolloid (HC) and hydrogel (HG) occlusive dressings and a polyethylene (PE) semi-occlusive dressing on the healing of acute full-thickness skin wounds on the forelimbs of 10 dogs. All treatments resulted in a similar degree of healing at postoperative days 4 and 7. No significant differences existed in the number of wounds that were more than 90% healed at postoperative day 28 between the group treated with the HG dressing and the group treated with the PE dressing. There were significantly fewer wounds more than 90% healed at postoperative day 28 in the group treated with the HC dressing. Wounds under the HG dressing had the largest mean percentage of contraction at postoperative days 21 and 28. Wounds under the HG dressing also had the largest contraction/re-epithelialization ratio (postoperative days 21 and 28) compared with wounds under the PE and HC dressings. Wounds under the PE dressing had a significantly higher mean percentage of re-epithelialization than wounds under both occlusive dressings on postoperative days 14, 21, and 28. Wounds under the two occlusive dressings had exuberant granulation tissue present more often than wounds under the PE dressing. The two occlusive dressings had significantly higher bacterial counts on wounds compared with wounds under the PE dressing; analysis of variance (ANOVA), P = .0008. Wounds under the HC dressing showed the poorest healing in all parameters.

Animals↗

The roles of Clostridium difficile and enterotoxigenic Clostridium perfringens in diarrhea in dogs.

In this prospective study, feces of dogs with diarrhea were compared with feces of normal dogs for the presence of Clostridium difficile, C difficile toxins A and B, C perfringens, and C perfingens enterotoxin (CPE). C difficile toxins A, B, or both were present in feces of 18 of 87 (21%) dogs with diarrhea and 4 of 55 (7%) normal dogs (P = 0.03), whereas CPE was present in the feces of 24 of 87 (28%) dogs with diarrhea and 3 of 55 (5%) normal dogs (P = 0.01). C difficile was isolated from 2 of 87 (2%) dogs with diarrhea but was not isolated from the feces of 55 normal dogs, possibly because of poor survival of the organism in fecal samples. C perfringens was isolated from the feces of 23 of 24 (96%) CPE-positive dogs with diarrhea, 52 of 63 (83%) CPE-negative dogs with diarrhea, and 39 of 55 (71%) CPE-negative dogs with normal feces. No correlation was found between C perfringens spore number and the presence of CPE.

Animals↗

The prevention of experimentally induced necrotic enteritis in chickens by avoparcin.

Four groups of about seventy 2-week-old broiler chickens were challenged with a Clostridium perfringens Type A isolate. Inclusion of avoparcin at 20 ppm in feed prevented necrotic enteritis in one group, but 10 ppm was only marginally effective. Bacitracin at 110 ppm also prevented the disease. Necrotic enteritis was successfully reproduced in untreated control birds.

Animals↗