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G R Carter

Publications and source records attributed to G R Carter.

At least 19 recordsLinked to original sources
PubMed1992

Conditions for transformation of Pasteurella multocida by electroporation.

Conditions for electroporation of plasmid DNA into Pasteurella multocida were determined for use in developing a cloning system to study virulence factors of P. multocida. The highest efficiency of transformation (1.25 x 10(7) cfu/micrograms DNA) was obtained when 7.6 x 10(10) cells of P. multocida strain R473 were electroporated at 12.5 kV/cm (10 ms, 5 ng of pVM109). Transformation efficiencies of cells prepared at mid-log-phase were approximately 0.5 log10 lower than early, late, or stationary phases. Neither pBR322 nor pUC-19 were able to transform strain R473 under these conditions, even when DNA concentrations were increased to 1 microgram. When pBR322 was ligated with a Pasteurella plasmid, pLAR-1, the hybrid was able to transform strain R473 at an efficiency between 4.5 x 10(2) and 8 x 10(4) cfu/micrograms DNA. Six strains of P. multocida including serotypes A, B, D, and E were transformed successfully.

Electric Stimulation↗
PubMed1989

Prevention of haemorrhagic septicaemia in buffaloes and cattle with a live vaccine.

Young cattle and buffaloes were vaccinated subcutaneously and intradermally with a live vaccine containing Pasteurella multocida serotype B:3,4. Twelve months after vaccination three of five young cattle in the subcutaneously vaccinated group and three of four in the intradermally vaccinated group were protected against serotype B:2 challenge. Eleven buffaloes vaccinated subcutaneously and two vaccinated intradermally survived the same challenge 13 months after vaccination.

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↗
PubMed1976

Multiple drug resistance in Pasteurella multocida and Pasteurella haemolytica from cattle and swine.

The results of antimicrobial susceptibility testing on 262 strains of Pasteurella multocida and 141 strains of Pasteurella haemolytica isolated from cattle and swine from 1971 to 1974 were analyzed for patterns of resistance to streptomycin, penicillin, tetracycline, and chloramphenicol, using a modified Kirby-Bauer procedure. Resistance was recorded for 80.5% of the isolants of P multocida and 92.2% of those of P haemolytica. Resistance to streptomycin was most frequent, followed by resistance to penicillin and tetracycline. Most cultures of P multocida and P haemolytica were susceptible to chloramphenicol. There were 9 patterns of resistance with the aforementioned antibiotics. The combinations, streptomycin and penicillin and streptomycin and tetracycline, each accounted for approximately 10% of the resistance patterns of P multocida. Approximately half of the 14 isolants of P haemolytica were resistant to the combination of streptomycin, penicillin, and tetracycline. These observations underscore the need for antimicrobial susceptibility testing of clinical isolants of P multocida and P haemolytica.

Animals↗
PubMed1976

Anaerobic bacteria from the large intestine of mice.

Anaerobic bacteria from the colon of laboratory mice were enumerated and isolated using strict anaerobic techniques. Direct microscopic counts revealed 4.4 X 10(10) organisms in each gram (wet weight) of colon contents. Actual cultural counts averaged 3.2 X 10(10) organisms, which was 73% of the direct microscopic count. The tentatively identified genera were Bacteroides, Eubacterium, Fusobacterium, Lactobacillus, Peptostreptococcus, and Propionibacterium. Strains of Fusobacterium, Lactobacillus, Peptostreptococcus, and Propionibacterium were biochemically homogeneous. Strains of Bacteroides and Eubacterium, on the other hand, were biochemically heterogeneous and were subdivided into several distinct groups. The data indicate that many of the isolates are different from previously described species of the respective genera and may belong to new species.

Anaerobiosis↗
PubMed1976

Gingival flora of the dog with special reference to bacteria associated with bites.

Gingival scrapings from dogs were examined to determine their aerobic bacterial flora. Of particular interest was the frequent recovery of three unclassified groups of aerobic gram-negative bacteria, IIj, EF-4, and M-5, previously associated with human dog-bite infections. Although no set pattern was found between the variability and consistency of gingival microbiota as related to age, sex, or breed of dog, a certain characteristic flora can be predicted in the healthy canine gingiva. Members of the following genera were found: Streptococcus, Staphylococcus, Actinomyces, Escherichia, Corynebacterium, Pasteurella, Caryophanon, Mycoplasma, Acinetobacter, Moraxella, Neisseria, Enterobacter, and Bacillus.

Animals↗
PubMed1975

Identification of Actinomyces viscosus from canine infections.

Actinomyces viscosus is a gram-positive, non-acid-fact, facultative, catalase-positive, filamentous, or diphtheroidal microorganism. It was isolated from six canine infections during a period of 1.5 years. The organism was cultured from exudate and flaky granules aspirated from infectious granulomas and empyemas. All cultures grew well aerobically and anaerobically with the addition of 10% carbon dioxide. They fermented lactose, produced catalase and acetylmethylcarbinol, reduced nitrates, hydrolyzed aesculin, and did not produce gelatinase or urease. These physiological characteristics distinguish A. viscosus from other morphologically similar organisms.

Actinomyces↗
PubMedDate not supplied

Efficacy of various methods of confidential unit exclusion in identifying potentially infectious blood donations.

To determine the efficacy of various methods of confidential unit exclusion (CUE) among donors at increased risk of HIV exposure, we surveyed AABB institutional members on their experience with 3 CUE methods: ballot or barcode, completed at the time of donation, and call-back, performed by the donor after leaving the donor center. From June 1985 to December 1987, 5,049,883 donations at 48 donor centers were evaluable for analysis. The results of this survey suggest that ballot and barcode methods of CUE are important adjuncts to other donor screening procedures in identifying potentially infectious units, and that both of these methods are superior to the call-back system of unit exclusion.

Blood Banking↗