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Binucleate classical mycoplasmas pathogenic for goats
Abstract:
The growth of three pathogenic goat mycoplasmas, strains Y, KH1 and Mycoplasma mycoides var. capri (PG3), was studied. They formed classical colonies on agar containing 1/500 thallium acetate. They were inactivated during storage at 2 to 4 C and by freezing and thawing but not by shaking. Only KH1 was killed by sonic treatment. Ultraviolet inactivation curves showed that their colony-forming units were single binucleate cells. Details of their growth curves are given. Filtration through 0.45- or 0.3-mum membrane filters removed up to 97% of the cells. Less than 0.003% passed 0.22-mum membranes. In electron micrographs, the cells were seen replicating by budding and most were 0.6 to 0.9 mum in diameter; but cells between 0.1 and 0.2 mum reproduced. They usually multiplied by producing one bud, a form of binary fission. However, two buds were produced by some synchronized cells, indicating that both nuclei had divided simultaneously to form progeny, an alternate method of multiplication.
Insights
Pathogenic goat mycoplasmas, including Mycoplasma mycoides, were studied for growth and survival. Findings reveal their sensitivity to storage, freezing, and filtration, with replication occurring via budding.
Area of Science:
- Veterinary Microbiology
- Mycoplasma Research
- Bacterial Physiology
Background:
- Goat mycoplasmas are significant pathogens in livestock.
- Understanding their growth characteristics is crucial for disease control.
Purpose of the Study:
- To characterize the growth and survival of three pathogenic goat mycoplasma strains.
- To investigate their response to various environmental conditions and physical treatments.
Main Methods:
- Cultivation on thallium acetate agar.
- Assessment of inactivation by storage, freezing, thawing, shaking, and sonic treatment.
- Ultraviolet inactivation studies.
- Membrane filtration experiments (0.45, 0.3, and 0.22 μm).
- Electron microscopy for cell morphology and replication analysis.
Main Results:
- All strains formed classical colonies on selective agar.
- Mycoplasmas were inactivated by cold storage, freezing/thawing, but not shaking.
- Strain KH1 was susceptible to sonic treatment.
- Ultraviolet inactivation indicated single binucleate cells.
- Filtration effectively removed mycoplasmas, with minimal passage through 0.22 μm filters.
- Electron microscopy revealed replication by budding, with cells ranging from 0.1 to 0.9 μm, often undergoing binary fission or simultaneous nuclear division.
Conclusions:
- Pathogenic goat mycoplasmas exhibit distinct growth and inactivation profiles.
- Replication occurs through budding and binary fission, with evidence of synchronized nuclear division.
- Filtration is an effective method for removing these mycoplasmas from cultures.