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Biomedical subjects

R N Gourlay

Publications and source records attributed to R N Gourlay.

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

Laboratory diagnosis of animal mycoplasma infections.

Laboratory diagnosis of animal mycoplasma infections is generally based on isolation of the mycoplasmas from the diseased tissues, followed by biochemical and serological identification of the isolates. However, the presence of serum antibodies and the demonstration of circulating antigen or antigen in infected lung tissue has also proved invaluable in the diagnosis of contagious bovine pleuropneumonia. The isolation of a particular mycoplasma from a diseased tissue does not necessarily imply a causal relationship. It is important to know the pathogenicity potential of the mycoplasma in question, the number of mycoplasmas present, the presence of any other potentially pathogenic microorganisms and any other relevant information before the role of the mycoplasma can be assessed and a diagnosis of mycoplasma infection given.

Animals↗
PubMed1981

Mycoplasmosis in cattle, sheep and goats.

Nineteen species or subspecies of mycoplasma infect cattle and 17 species or subspecies infect sheep and goats; of these only three are common to both groups of animals. Diseases associated with mycoplasmas are found in the respiratory and urogenital tracts, mammary glands, joints and eyes. Some of these species of mycoplasma are highly pathogenic, causing diseases of major importance, namely, contagious bovine pleuropneumonia, contagious caprine pleuropneumonia and contagious agalactia. This paper, however, will principally consider the roles, if any, of the various other species of mycoplasma in diseases of cattle, sheep and goats.

Animals↗
PubMed1981

Mycoplasma-induced arthritis in farm animals.

Mycoplasma-induced arthritis in farm animals is rarely diagnosed. When recognized, it is usually associated with mycoplasma infections at other anatomical sites such as the respiratory tract and mammary glands and presumably follows bacteremia. Cases do occur where arthritis appears to be the primary lesion, but this may only reflect a failure to recognize infection at other sites. In cattle, the mycoplasma species causing arthritis are M. bovis, M. mycoides subsp. mycoides, Mycoplasma spp. Group 7 and Mycoplasma spp. serotype L. In sheep and goats, M. capricolum can cause severe polyarthritis, while M. hyorhinis and M. hyosynoviae have been incriminated in arthritis in pigs.

Animals↗
PubMed1980

Immunity to Mycoplasma bovis infections of the respiratory tract of calves.

Calves were inoculated intramuscularly with formalin killed Mycoplasma bovis with adjuvant and after 14 days intratracheally with killed organisms without adjuvant. Seven days later they were challenged intratracheally and 21 days after challenge they were found to have significantly fewer M bovis in their lungs than control calves. Two intramuscular or two intratracheal inoculations of killed M bovis were not found to induce resistance but imunity could be stimulated by three subcutaneous inoculations of inactivated mycoplasmas with adjuvant. Immunity was correlated with antibody detectable in lung washings by the single radial haemolysis technique. Combined intramuscular and intratracheal administration of killed M bovis induced a better antibody response in lung washings than two intramuscular or two intratracheal inoculations. Antibody was also detected in lung washings from calves inoculated three times subcutaneously but in this case it was thought to be derived from serum. The antibody detected in lung washings by single radial haemolysis was found to be IgG by radioimmunoassay.

Animals↗
PubMed1979

Comparison of mycoplasmatales virus MV-Lg-pS2-L172 with plasmavirus MV-L2 and the other mycoplasma viruses.

Mycoplasma virus MV-Lg-pS2-L172 was sensitive to heat (56 degrees C/30 minutes), Nonidet-P40 and ether. In these respects it resembled Plasmavirus MB-L2. However, it differed from MV-L2 (and the other mycoplasma viruses, MV-L1, MV-L3 and BN1 virus) in reciprocal plaque inhibition and serum neutralization tests (MV-L2 only). By plaque formation on host lawns resistant to the different mycoplasma viruses, including MV-Lg-pS2-L172, this latter virus was shown to be distinct from the other viruses, including MV-L2. Both MV-Lg-pS2-L172 and MV-L2 possessed one polypeptide band (out of 10) that was not common to the heterologous virus.

Acholeplasma laidlawii↗
PubMed1979

The effect of an intramammary infusion of endotoxin on experimentally induced mycoplasmal mastitis.

The infusion of 10 microgram of endotoxin lipopolysaccharide from Escherichia coli into the mammary gland of four cows 16 h before inoculation with ureaplasmas did not prevent, or even diminish, the subsequent ureaplasmal mastitis. There was no reduction in the severity or duration of the inflammatory cell response in milk or in the clinical appearance of the resulting mastitis. Also, the excretion of ureaplasmas was not reduced. A similar experiment with Mycoplasma dispar in two cows demonstrated that endotoxin was again ineffective in preventing the mastitis. Furthermore, there was some indication that the proliferation and excretion of this mycoplasma was enhanced in endotoxin-treated quarters.

Animals↗
PubMed1979

Demonstration by electron microscopy of intracellular virus in Acholeplasma laidlawii infected with either MV-L3 or a similar but serologically distinct virus (BN1 virus).

Cultures of Acholeplasma laidlawii strain M1305/68 were inoculated with Mycoplasmatales virus-laidlawii 3 (MV-L3) and examined by electron microscopy. Particles resembling MV-L3 were observed both intra- and extracellularly in thin sections prepared from MV-L3 infected cultures, but not from uninfected cultures. Similar particles were occasionally observed in uninoculated cultures of A. laidlawii strain BN1 cells, from which a virus (BN1 virus) was subsequently isolated. This virus was morphologically similar but not identical to MV-L3. It also differed serologically from, and in its resistance to, MV-L3 and the other mycoplasma viruses.

Acholeplasma laidlawii↗
PubMed1979

Pathogenicity of some Mycoplasma and Acholeplasma species in the lungs of gnotobiotic calves.

Cloned cultures of 16 strains, representing nine different species of Mycoplasma and Acholeplasma, were inoculated intratracheally into gnotobiotic calves. Strains of M bovirhinis, M canadense, M verecundum, A axanthum and A modicum did not produce visible pneumonic lesions and were not reisolated from the lungs. Strains of M alkalescens and M arginini colonised the lower respiratory tract but failed to produce visible pneumonia. M bovigenitalium (strain M991/70) and M dispar (strain Gri226) both colonised the respiratory tract and induced pneumonic lesions estimated to involve up to 8 per cent (M bovigenitalium) and 17 per cent (M dispar) of the lung. Histologically M bovigenitalium produced a cuffing pneumonia and M dispar produced a interstitial alveolitis.

Acholeplasma↗
PubMed1977

Protective effect of vaccines on Mycoplasma pulmonis-induced respiratory disease of mice.

Mice inoculated intranasally with either a virulent or an avirulent strain of live Mycoplasma pulmonis were resistant to respiratory disease induced by a subsequent intranasal challenge with virulent organisms. Similarly, mice inoculated intravenously with the virulent strain were resistant to intranasal challenge with the same strain. In contrast, mice inoculated intravenously with avirulent M. pulmonis were not resistant to intranasal challenge with the virulent mycoplasma strain. Studies on mice inoculated intravenously with the two strains of M. pulmonis indicated that persistance of mycoplasmas in the respiratory tract may be important in inducing resistance to intranasal challenge with M. pulmonis. These observations, together with the lack of correlation between the level of serum antibodies and resistance to M. pulmonis-induced respiratory disease, suggested that local immune mechanisms were important in resistance. It is proposed that an effective vaccination schedule to protect mice against M. pulmonis-induced respiratory disease may be one that stimulates both systemic and local immune defenses. This suggestion is supported by the observation that systemic followed by local administration of inactivated M. pulmonis was more effective in inducing resistance in mice to intranasal challenge with live organisms than was systemic administration alone. In addition, mice inoculated solely by the intranasal route with inactivated mycoplasmas were resistant to M. pulmonis-induced respiratory disease. These studies indicate the importance of local defense mechanisms in the induction of resistance to M. pulmonis-induced respiratory disease in mice.

Administration, Intranasal↗
PubMed1976

Experimental mycoplasma mastitis in mice.

Thirteen strains of mycoplasma representing six different species, Acholeplasma laidlawii, Mycoplasma dispar, M. bovirhinis, M. bovigenitalium, M. agalactiae subsp. bovis, and M. mycoides subsp. mycoides, were inoculated into the mammary glands of mice, and the number of mycoplasmas present in the glands three days after inoculation was determined. The predominant response included involution of inoculated glands and a neutrophil infiltration. With the exception of M. dispar, the pathogenicity of the six species for mice was found to be similar to their pathogenicity for cattle.

Acholeplasma laidlawii↗