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Biomedical subjects

J B Woolcock

Publications and source records attributed to J B Woolcock.

At least 37 records · Page 2Linked to original sources
PubMed1981

The isolation of antibiotic resistant coliforms from meat and sewage.

Beef and pig carcases, meat products, frozen chickens, and sewage were examined in 3 separate surveys for antibiotic resistant coliforms. Escherichia coli was isolated from 18 of 50 beef carcases; the numbers were low and resistance was found only to tetracycline. E. coli was isolated from 45 to 50 pig carcases; the numbers were high and showed a range of patterns of multiple antibiotic resistance. In meat products, the proportion of E. coli in contaminating organisms was low, and most resistance found was to tetracycline and streptomycin. E. coli was isolated from 66 of 75 chickens and these gave 23 patterns of antibiotic resistance, often multiple. Sewage from hospital or domestic origin and abattoir effluent yielded approximately 10(6) coliforms/ml, most of which were resistant to one or more antibiotics; few of those from hospital or domestic origin however, were classified as E. coli of faecal origin. Twenty-four patterns of resistance were found in coliforms from domestic sewage, 19 from hospital sewage and 11 from abattoir effluent. Transfer of resistance, often multiple, was achieved from 55% of 447 resistant strains to an E. coli K12 recipient. Much more information is required on the prevalence of R-factors in bacteria associated with food producing animals and their products.

Abattoirs↗
PubMed1980

Corynebacterium equi in cattle and pigs.

The cervical lymph nodes of pigs, the retropharyngeal and submandibular lymph nodes of cattle and faecal samples from both animal species were examined for the presence of Corynebacterium equi. The organism was recovered from 19 (35 per cent) of 54 porcine cervical lymph nodes and from 0 of 54 bovine retropharyngeal and submandibular lymph nodes. Fifteen (50 per cent) of 30 bovine faecal and 11 (35 per cent) of 31 porcine faecal samples yielded C. equi.

Animals↗
PubMed1980

Epidemiology of Corynebacterium equi in horses.

Using a selective medium, the epidemiology of Corynebacterium equi in horses was studied. Twelve horse studs in different geographical locations were investigated. In addition, a group of horses was monitored over a period of time to determine whether faecal carriage of C equi is constant or intermittent. It was found that C equi could be recovered from every property tested and from all horse breeds. The organism was found in mares, stallions, yearlings and two year olds, and foals aged from 10 days to several months. It appears that C equi is widespread and that its occurrence is not related to any particular geographical location nor to a limited number of properties within a given area. Furthermore, it seems likely that C equi is part of the normal equine faecal flora. The results challenge the notion that C equi is primarily soil associated and do not support the concept that there are infected and non-infected areas.

Animals↗
PubMed1979

Selective medium for Corynebacterium equi isolation.

The development of a selective medium for the isolation of Corynebacterium equi is described. The medium has been used to examine fecal samples from 127 horses of which 90 have been found to carry the organism.

Animals↗
PubMed1978

The capsules of Corynebacterium equi and Streptococcus equi.

The capsules of Corynebacterium equi and Streptococcus equi were examined by electron microscopy after staining with ruthenium red. They were compared with the capsule of Klebsiella pneumoniae which had previously been examined using the same procedure (Springer & Roth, 1973). The capsule of C. equi had a laminated appearance. When S. equi was grown on solid medium, its capsule appeared as radially arranged projections capped by a thick electron dense layer. When grown in liquid medium, S. equi produced a capsule which showed as short thick projections with no layer external to them.

Cell Wall↗
PubMed1977

Some factors affecting selective adherence of microorganisms in the bovine mammary gland.

Some parameters affecting the adherence of microbes to the ductular epithelium of the bovine mammary gland were studied. Adherence increased from teat sinus to lactiferous sinus to the large ducts, and cells from the lactiferous sinus to the large ducts, and cells from the lactiferous sinus were used for all other experiments. There was no difference in adherence to cells from different quarters of the same cow, but there were significant differences between cows. Scanning electron microscopy suggested that the cells of the ductular epithelium undergo dynamic changes that probably result in secretion and/or desquamation. Adherence to cells could be demonstrated only at a late stage of these changes. The adherence of organisms associated with mastitis was studied using an in vitro test. Adherence generally paralleled prevalence as cause of disease, with Staphylococcus aureus and Streptococcus agalactiae adhering best. Strain variation suggested that virulence was related to adherence with S. agalactiae and S. dysgalactiae but not with S. aureus. It is proposed that specific adherence is an important aspect of pathogenesis of mastitis due to S. aureus and S. agalactiae.

Adhesiveness↗
PubMed1976

Immune mechanism in Pasteurella multocida-infected mice.

Various immunizing procedures were tested for their effect on the growth of Pasteurella multocida in specific pathogen-free CD-1 mice. Two injections with killed vaccine incorporated into Freund complete adjuvant gave excellent protection against parenteral challenge, but less to control the growth of an aerogenic inoculum. Protection with adjuvant-treated preparation was always superior to that seen with non-adjuvant-treated vaccines. A killed saline-suspended vaccine introduced aerogenically marginally increased resistance to small (2 to 5 mean lethal doses) aerogenic challenges. Live mycobacterium bovis (BCG) vaccine immunopotentiated a single dose of heat-killed P. multocida vaccine in terms of the protective immune response against a subsequent footpad challenge. Hyperimmune mouse serum, administered intraperitoneally, intramuscularly, or intravenously 1 to 7 days prior to subcutaneous challenge with 500 to 5,000 P. multocida, was highly protective. Mice injected in the thigh with 0.2 ml of hyperimmune serum prior to footpad challenge frequently developed a severe inflammatory response with local swelling within 48 h; these lesions often became severly abscessed with time. The passively protected, footpad-infected mice developed active immunity against a subsequent challenge given into the opposite footpad.

Administration, Intranasal↗
PubMed1975

Involvement of the upper respiratory tract in orally induced salmonellosis in mice.

The possible involvement of the tissues of the head and neck during the early pathogenesis of orally or intragastrically induced murine salmonellosis was examined. Viable counts of Salmonella in the local lymphoid tissues and draining nodes indicated that the ileal Peyer's patches were primarily involved in the development of a subsequent enteric fever, irrespective of the method of oral challenge. Contamination of drinking water with a high concentration of salmonellae produced infection of the ileal Peyers patches and the eventual development of systemic disease. The cervical lymph nodes were sporadically involved early in the infection, but this involvement soon became general, with large numbers of salmonellae in the cervical nodes by 36 hr. A lower concentration of salmonellae in drinking water led to primary involvement of the ileal Peyers patches; upper respiratory tract involvement was detected much later in the infection. Intragastrically invected mice exhibited the same low-level infection of the cervical lymph nodes as that in mice infected via drinking water. Thus systemic infection apparently results from infection of the ileal Peyers patches; a small percentage of the animals develop a concurrent upper respiratory tract infection that may be responsible for the development of carrier states after enteric infection.

Animals↗
PubMed1975

Immunity to Streptococcus equi.

Using the long chain test, and in some cases the bactericidal test, to measure antibody, the development of the immune response in horses to Str. equi has been followed. Long chain indices in excess of 5.0, accompanied by strong bactericidal capacity, were recorded in serums after the full 3-dose immunisation course with a commercial vaccine. The full course elicited the most satisfactory antibody titres declined within the 12 month post-vaccination period, thus providing support for the recommendation that yearly booster doses should be administered. The immune response in horses during 2 strangles outbreaks was compared with the response following vaccination. Recovered animals showed declining antibody levels 9 weeks after infection, and the evidence does not support longevity of the immune response after natural infection. Reaction to vaccination was observed in those animals with high initial antibody titre.

Animals↗
PubMed1975

Epidemiology of equine streptococci.

Equine tonsillar tissue and the draining regional lymph nodes, as well as deep nasal swabs were examined bacteriologically. Group C streptococci, predominantly Streptococcus zooepidemicus, were shown to be present in all tissues. The most frequent site for isolation was the tonsil. Streptococcus equi was not located in any of the tissues sampled.

Animals↗
PubMed1975

Studies in atypical Streptococcus equi.

An atypical variety of Streptococcus equi is described. It was shown to be deficient in capsular material, to be very virulent for mice and to possess a cell-wall protein similar to the M-like protein of classical Str equi. Antiserum prepared against classical Str equi effectively opsonised the atypical strains, and induced the formation of long chains by these atypical strains. It is possible that this variant of Str equi can be used to overcome many of the current problems associated with the manufacture and use of strangles vaccines.

Animals↗
PubMed1974

Purification and antigenicity of an M-like protein of Streptococcus equi.

A cell wall component of Streptococcus equi analogous to the M protein of group A streptococci has been identified and purified. A highly purified product has been obtained from cells by hot acid extraction, followed by acid precipitation, ammonium sulfate fractionation, and column chromatography. This product reacts with S. equi antiserum. The existence of this fraction in S. equi has been confirmed by the failure of trypsin-treated cells and their extracts to remove the long-chaining capacity of S. equi antiserum. The antigenicity of this M-like protein when incorporated in adjuvant has been assessed in rabbits and horses. In the rabbit, multiple doses of as low as 10 mug resulted in the production of serum capable of inducing long-chain formation and opsonizing and mouse protective antibody. Two doses of 100 mug elicited similar responses. The bactericidal capacity of this serum could be eliminated by absorption with whole S. equi cells or their extracts, but not by absorption with trypsin-treated cells or extracts therefrom. Horses vaccinated 15 months previously with a whole-cell killed vaccine and given 200 mug of the purified protein intramuscularly showed evidence of an anamnestic response to the antigen.

Absorption↗