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Biomedical subjects

G R Carter

Publications and source records attributed to G R Carter.

At least 37 records · Page 2Linked to original sources
PubMed1986

Identification of type D Pasteurella multocida by counterimmunoelectrophoresis.

A counterimmunoelectrophoresis (CIE) test was applied to serotype 35 isolates of type D Pasteurella multocida recovered from 32 cases of atrophic rhinitis (in swine) and 3 cases of snuffles (in rabbits). The CIE test was compared with the indirect hemagglutination (IHA) and acriflavine (AF) tests. Results of the CIE test correlated 100% with those of the IHA test whereas results of the AF test correlated 91.43% with those of the IHA test. The CIE test was rapid and simpler to perform compared with the IHA test and more sensitive than the AF test. Cross-reactions were not encountered with capsular antigens of P. multocida types A, B, and E in the CIE test. The CIE test was not found to be suitable for typing type A P. multocida strains.

Acriflavine↗
PubMed1985

Pneumonia in calves produced with aerosols of Pasteurella multocida alone and in combination with bovine herpesvirus 1.

Pathological changes in respiratory tracts were studied in 30 calves following exposure to aerosols of Pasteurella multocida or to bovine herpesvirus 1 and P. multocida. Two groups of five calves were exposed to aerosols of one of two types of P. multocida only, which produced lobar pneumonia in one calf of each group. Another five groups of four calves were exposed to aerosols of bovine herpesvirus 1 and four to seven days later to one of the two types or one sub-type of P. multocida. Extensive necropurulent lesions were produced throughout the respiratory tract with each type of P. multocida in all four calves in three groups but none in the remaining two groups. The pathological changes differed from those produced following similar exposures to bovine herpesvirus 1 and P. haemolytica, in that the exudate in air passages and alveoli was more purulent and streaming (oat) cells and large mononuclear eosinophilic granulocytes were absent. This is the first report of experimental respiratory disease in cattle as a result of aerosol exposure to P. multocida alone or in combination with bovine herpesvirus 1.

Aerosols↗
PubMed1984

Comparison of indirect hemagglutination and rapid plate agglutination tests with counterimmunoelectrophoresis for typing Pasteurella haemolytica.

A rapid, simple, and accurate counterimmunoelectrophoresis (CIE) technique was developed and compared with the indirect hemagglutination and rapid plate agglutination techniques for serotyping cultures of Pasteurella haemolytica. The CIE test had 100% correlation with the conventional indirect hemagglutination test and, after serum absorption, correctly identified cultures representing the 12 established serotypes and 49 field isolates of P. haemolytica with reasonable rapidity. Cross-reactions were observed in the CIE and rapid plate agglutination tests but not in the indirect hemagglutination test with antisera prepared from the 12 established serotypes. These cross-reactions were eliminated from the CIE test but not from the rapid plate agglutination test by absorption of antisera with cells which possessed the cross-reacting antigens. Avian isolates of P. haemolytica did not type with antisera to the 12 established serotypes by any of the methods. Both homologous and heterologous reactions were observed with these strains in the rapid plate agglutination and CIE tests with antisera prepared from six selected cultures. These results support the previous finding that the taxonomic relationship of these avian strains to P. haemolytica is questionable.

Agglutination Tests↗
PubMed1982

Capsular and somatic types of Pasteurella multocida from rabbits.

Capsular and somatic serotyping was performed on 79 cultures of Pasteurella multocida from rabbits. Of these isolates, 74 were capsular type A as determined by the staphylococcal hyaluronidase decapsulation test and five were type D by the acriflavine flocculation test. Somatic type 12 was the dominant serotype, and the remainder (type 1, 3, 4 and 11) were less frequent as determined by the gel diffusion precipitin test. This report is in general agreement with other recent reports with rabbit isolates and collectively they provide important serotype and epizootiological information that will be useful in the control and prevention of rabbit pasteurellosis.

Animals↗
PubMed1980

Preliminary field trails with a streptomycin-dependent vaccine against haemorrhagic septicaemia.

In two trials, 68 cattle and buffalo calves, four to 10 months of age, were vaccinated with a vaccine containing a live streptomycin dependent mutant of Pasteurella multocida type B, isolated in Sri Lanka. Immunity was assessed using the passive protection test in mice with cattle and buffalo sera before and two or three weeks after vaccination. A single dose of vaccine conferred immunity in 66.6 to 83.3 per cent of cattle and 100 per cent of buffalo calves. A booster dose given three weeks later enhanced the immunity in cattle. There was no significant difference in the response, whether the vaccine was administered by the subcutaneous or intramuscular route. No adverse reactions were observed in any of the vaccinated animals.

Animals↗
PubMed1980

Hyaluronidase production by type B Pasteurella multocida from cases of hemorrhagic septicemia.

Seventy-four cultures of Pasteurella multocida representing all four capsular types, A, B, D, and C, from various animal species and diseases were examined for the production of hyaluronidase by two procedures. In one, hyaluronidase production was determined by the depolymerization of streptococcal capsular hyaluronic acid, and in the other, production was determined by degradation of sodium hyaluronidate in a solid culture medium. Hyaluronidase production was only demonstrated in the 13 type B cultures that had been recovered from cases of hemorrhagic septicemia.

Animals↗
PubMed1980

Production and characterization of streptomycin dependent mutants of Pasteurella multocida from bovine haemorrhagic septicaemia.

A large number of streptomycin dependent mutants were produced from bovine haemorrhagic septicaemia strains of Pasteurella multocida. The mutants required a minimum concentration of 25-50 microgram/mL streptomycin for growth and tolerated a concentration of 200 mg/mL. These mutants were avirulent to mice, when inoculated alone, but some mutants killed mice when inoculated with streptomycin. Biochemically all mutants were uniform and similar to the wild type. Most mutants were stable, but a few produced streptomycin independent revertants. The rate of reversion varied with each mutant. Most revertants were highly virulent for mice, some totally avirulant and a few relatively avirulent.

Animals↗
PubMed1980

A streptomycin dependent live Pasteurella multocida vaccine for the prevention of rabbit pasteurellosis.

A culture of Pasteurella multocida was isolated from a rabbit exhibiting clinical signs of respiratory pasteurellosis. Organisms from this culture were incubated in the presence of the mutagen n-methyl-n'-nitro-n-nitrosoguandine in order to obtain a streptomycin dependent mutant. A live vaccine was prepared from this mutant, and healthy pasteurella-free rabbits were vaccinated either by intranasal or subcutaneous administration. Either method provided complete protection against homologous, wild-type challenge as evidenced by absence of clinical signs or gross pathology and failure to isolate the organism from mucous secretions of tissues from vaccinated individuals.

Animals↗
PubMed1978

Live streptomycin-dependent Pasteurella multocida vaccine for the prevention of hemorrhagic septicemia.

A type B Pasteurella multocida was used for the development of a streptomycin-dependent (StrD) vaccine. Pasteurella multocida R-473, a hemorrhagic septicemia strain, was mutagenized with N-methyl-N'-nitro-N-nitrosoguanidine to increase the likelihood of encountering a StrD mutant and was plated on agar containing 400 microgram of streptomycin/ml. Replica plating was used to differentiate dependent from resistant colonies. Mice and rabbits were vaccinated with a StrD mutant and 21 days later, were challenge exposed, along with unvaccinated controls, with the wild type R-473. Protection of greater than 4 logs was shown for the vaccinated mice. All vaccinated rabbits were protected and all nonvaccinated controls succumbed to a challenge exposure of 500 or 1,000 LD50.

Animals↗
PubMed1977

Immune responses of the bovine fetus.

The bovine fetus is capable of mounting an antibody response when a bacterial antigen (killed Escherichia coli) or viral antigen (live reovirus) is deposited into the amniotic fluid. Time required for the fetus to respond to bacterial antigen given orally (amniotic fluid) is approximately 10 to 14 days and 8 to 10 days for viral antigen. Calves vaccinated prenatally with E. coli from 9 to 102 days before birth and deprived of colostrum survived oral challenge doses of viable E. coli which killed calves not vaccinated prenatally. One mechanism of protection was the local production of antibody in the gastrointestinal mucosa where immunofluorescent techniques showed immunoglobulins IgG, IgM, and anti-E. coli antibody in the duodenum, jejunum, and ileum as well as in the jejunal lymph node. Prenatal vaccination has been used in the field for prevention of colibacillosis. However, the occurrence of some stillbirths and premature births indicates the need for further research before there can be widespread field application of the technique.

Amniotic Fluid↗
PubMed1977

Demonstration of bacteriocin activity in bovine and bison strains of Pasteurella multocida.

Of 33 strains of Pasteurella multocida examined, 14 showed bacteriocin activity and 17 were susceptible to bacteriocin. The activity was increased by about twofold if the cultures were induced with ultraviolet radiation; however, no increase in bacteriocin activity was observed if the potential producer strains were induced with mitomycin C. The bacteriocin activity of potential producer strains was increased if CaCl2 was incorporated in the medium. The patterns of bacteriocin susceptibility indicate that these substances may ultimately contribute to a typing scheme for the species. An extra-chromosomal genetic element was not detected when a potential producer strain was not detected when a potential producer strain was tested by the dye-buoyant density gradient method. This fact suggests that the genetic material responsible for bacteriocin activity in P multocida is located on the host chromosome proper.

Animals↗