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Mycoplasmacidal activity of bovine milk for T-mycoplasmas
Abstract:
Normal bovine milk and whey was mycoplasmacidal for 6 of the 13 strains of bovine T-mycoplasmas examined. The in vitro assay used also demonstrated no killing of the human, canine and simian T-mycoplasma strains after 4 hr. incubation. However, there appeared to be some cow-to-cow variation in possession of this activity, and following E. coli endotoxin stimulation of the mammary gland the activity was considerably reduced.Whey from three normal cows was fractionated on a Bio-Gel A 1.5 m. column and the mycoplasmacidal activity of the resulting five peaks assayed. Only the second peak, peak B, contained activity and was characterized as the only peak containing bovine IgA. The active component in whey, however, was found to be heat stable at 60 degrees C. for 60 minutes and to pass through a dialysis membrane. This is inconsistent with it being immunoglobulin.
Insights
Bovine milk and whey exhibit mycoplasmacidal activity against certain T-mycoplasma strains. This activity, found in whey fraction B, is heat-stable but its exact nature remains unclear, despite association with bovine IgA.
Area of Science:
- Veterinary Microbiology
- Immunology
Background:
- T-mycoplasmas are significant pathogens in cattle.
- Bovine milk and whey possess antimicrobial properties.
Purpose of the Study:
- To investigate the mycoplasmacidal activity of normal bovine milk and whey against T-mycoplasma strains.
- To characterize the component responsible for this activity.
Main Methods:
- In vitro mycoplasmacidal assays were performed on bovine T-mycoplasma strains.
- Whey fractionation using Bio-Gel A 1.5 m. chromatography.
- Assay of mycoplasmacidal activity in fractionated whey peaks.
- Characterization of the active component's stability (heat, dialysis).
Main Results:
- Normal bovine milk and whey demonstrated mycoplasmacidal activity against 6 of 13 bovine T-mycoplasma strains.
- No activity was observed against human, canine, or simian T-mycoplasma strains.
- The mycoplasmacidal activity was localized to fraction B, which contained bovine IgA.
- The active component was heat-stable (60°C for 60 min) and dialyzable, properties inconsistent with immunoglobulin.
Conclusions:
- Bovine whey contains a mycoplasmacidal factor effective against certain bovine T-mycoplasma strains.
- The active component's characteristics suggest it may not be solely immunoglobulin, despite its association with IgA.
- Further investigation is needed to elucidate the precise nature of this heat-stable, mycoplasmacidal factor.