Detection of Mycoplasma bovis in Preservative-Treated Field Milk Samples

摘要

Control of mycoplasmal mastitis requires individual cow milk sampling for culture and identification of My- co Plasma bovis. This sampling is time-consuming and expensive. Currently, some herds sample cows monthly with the dairy herd improvement (DHI) program, but a preservative is added to this milk that kills M bovis. In this paper, a nested polymerase chain reaction (PCR) procedure that allows for rapid testing of preservative- treated milk is validated. The specificity of the nested PCR assay was confirmed by testing isolated nucleic acids of other organisms phylogenetically related to M bovis or common to milk. A comparison against blind- passage culture on 53 field milk samples determined its sensitivity. Exposure of seeded milk samples to the procedure resulted in a sensitivity of 5. 1 cf u equivalents per milliliter. Analysis of these results proved that the nested PCR assay was as sensitive as traditional cul- ture and can be used on preservative-treated milk.