Isolation of Mycoplasma mycoides subspecies mycoides from Polyarthritis and Mastitis of Goats in Canada

The clinical signs, pathomorphological changes, and microbiological findings in Canadian goats infected with Mycoplasma mycoides subspecies mycoides are discussed. The disease affected mainly young goats and was characterized by septicemia and polyarthritis. Mastitis followed by septicemia was seen in two mature goats. The diagnosis was made by culture and identification of the mycoplasma. Infected goats without clinical signs were identified by cultural and serological (complement fixation) techniques. Healthy carriers are presumably able to transmit the infection and may have brought the disease to Canada.     

Immunoprophylaxis of experimental Mycoplasma bovis arthritis in calves. Protective efficacy of live organisms and formalinized vaccines

Live Mycoplasma bovis (M. bovis) organisms given subcutaneously or intraperitoneally protected nine of ten calves and eight of nine calves, respectively, from clinical arthritis, while the formalinized vaccine given subcutaneously protected eight of ten calves. In contrast, clinical arthritis was induced in all non-vaccinated calves that were challenged intravenously. The arthritic lesion was more severe in non-vaccinated calves than in the few vaccinated calves that developed clinical arthritis. Unlike formalinized vaccine, live M. bovis culture given subcutaneously provoked a local reaction at the site of injection in most calves in the form of oedematous plaques of about 7–8 cm in diameter. Results suggest that the formalinized vaccine may offer a practical approach to the control of Mycoplasma bovis arthritis in calves.     

The effect of antibiotics against bovine mycoplasmas and ureaplasmas.

A combination of lincomycin-spectinomycin-tylosin was tested against several strains of mycoplasmas and acholeplasmas as might be encountered in bovine semen and shown to be effective against them. This combination as well as minocin , rosaramicin, rosoxacin, tiamulin, gentamicin and declomycin were tested in vitro against 58 isolates of ureaplasma from the bovine urogenital tract. The lincomycin-spectinomycin-tylosin combination, minocin , rosaramicin, tiamulin and declomycin were quite active, while rosoxacin and gentamicin were much less active against the test strains.     

Changes in plasma fibrinogen levels in experimental Mycoplasma bovis arthritis in calves

Plasma fibrinogen levels were measured as a means of following the course of an intravenous and intraperitoneal challenge of vaccinated and non-vaccinated animals in an experimental Mycoplasma bovis arthritis in calves. Intraperitoneal challenge failed to induce as much elevation of fibrinogen concentration as intravenous challenge in both the vaccinated and non-vaccinated groups.The elevation of fibrinogen levels among the vaccinated calves remained within the normal range of 300–800 mg% throughout, irrespective of the route of challenge. In contrast, the level rose to over 1600 mg% ten days postchallenge in all but one of the non-vaccinated calves that were challenged intravenously. The relatively low plasma fibrinogen levels in non-vaccinated calves that were challenged intraperitoneally correlated with the absence of arthritis in this group. In general, there was an inverse correlation between high fibrinogen levels and protection from M. bovis arthritis.     

Isolation of Ureaplasma from bovine granular vulvitis.

Cultures for mycoplasmatales, viruses and bacteria were made from bovine vulvar swabs to determine whether ureaplasma was associated with a clinical granular vulvitis observed in 16 Ontario dairy herds. Ureaplasma was isolated from 23.5% of 34 clinically normal cows, 74% of 27 cows with mild to moderate vulvar hyperemia but no discharge and 100% of 20 cows with acute vulvar hyperemia accompanied by purulent discharge. There were statistically significant differences in rates of isolation among clinical groups. Mycoplasma bovigenitalium was isolated from 7.7% and 20% of cows with moderate or acute vulvitis respectively but not from normal cows. Haemophilus somnus was isolated from 25% of cows with acute vulvitis. There were no significant differences in isolations of Escherichia coli, Corynebacterium pyogenes and alpha-hemolytic streptococcus between normal and clinically affected animals. Cultures of 135 repeat samples from 33 cows revealed that ureaplasma persisted in some animals for at least three months. No viruses were isolated from any of the animals in this study.     

The effect of intrauterine inoculation with Ureaplasma diversum on bovine fertility.

To determine the influence of Ureaplasma diversum on bovine fertility 11 uninfected virgin heifers with normal ovarian cyclic activity were randomly allocated to test or control groups. At a synchronized estrus, five test heifers were given an intrauterine broth inoculum containing 1.09 x 10(8) to 1.4 x 10(9) colony forming units of U. diversum and six control animals were infused with sterile ureaplasma broth medium. All animals were artificially inseminated within one hour of infusion. Pregnancy was diagnosed in one of five test heifers and all of six controls by serum progesterone concentrations measured to 25 days postinsemination. The difference in pregnancy rates between the two groups was statistically significant (p = 0.0152). It was concluded that under the conditions of this experiment U. diversum is capable of causing infertility in cattle.     

The recovery of Mycoplasmas from the genital tracts of bulls in artificial breeding units in Ontar?o.

One hundred and thirty-two penial-preputial swabbings, 140 raw and 42 processed semen samples were cultured for mycoplasmas. Mycoplasma or acholeplasma were recovered from 87, 32 and one respectively, while ureaplasmas were recovered from 46, 34 and six respectively.