マウスに多発性関節炎を起こすMycoplasma
1974 年 48 巻 2 号 p. 47-56
詳細
1974 年 48 巻 2 号 p. 47-56
Biological characteristics, identification, pathogenicity against mice and sensitivity to various chemotherapeutic drugs were studied on 23 strains of Mycoplasma isolated from rats and mice suffering from the so-called chronic respiratory disease (CRD). The results obtained were as follows:
1) The isolates could grow well in the basal PPLO medium supplemented with 20 ml of pooled horse serum and 10ml of a 25% extract of fresh yeast per deciliter at 37°C under aerobic condition.
After ten-day incubation, size of large colonies grown on the agar medium was 1 mm in diameter.
The organisms fermented dextrose, maltose and dextrin, but they were inactive against galactose and lactose. When 48-hour cultures were tested, the reduction of methylene blue rapidly completed. However, they did not reduce 2, 3, 5-triphenyl-tetrazolium chloride (TTC) under aerobic conditions. Production of film and spot was shown only in one out of 23 strains.
2) These isolates were identified to be Mycoplasma pulmonis based on their biological characteristics and the results obtained in growth inhibition and double gel diffusion tests.
3) Using the antisera that were absorbed with the liquid medium to remove the antibodies against the ingredients of this medium, especially horse serum, double gel diffusion test showed that M. pulmonis has two to three common antigens.
4) Complement fixation antibody titers in sera from mice at the 30 days after intravenous inoculation were measured at a high level of 1280 to 5120.
5) Intravenous inoculation with about 109 CFU/ml of isolates' strain suspension in physiological saline solution caused polyarthritis in mice 3 to 20 days later. Frequency of pneumonia induction was lower than that of appearance of polyarthritis. Mycoplasma was recovered from these affected tissues of the inoculated animals.
6) Intramuscular administration of hydrocortisone acetate (2.5mg/mouse) induced in higher rate pneumonia, but much the same about polyarthritis compared with cortisone non administrated group.
7) The pathogenicity against mice of the strain was maintaned even after 50 subcultures in culture medium.
8) Those isolates were equally sensitive to various chemoterapeutics such as macrolide antibiotics, nitrofurantoins and chloramphenicol, lincomycin, mikamycin, streptomycin and kanamycin.
