FIG. 1.

Detection of A. marginale in salivary glands isolated from individual adult male B. microplus or D. andersoni ticks. DNA of individual tick salivary glands was PCR amplified with msp5 primers and amplicons hybridized with a digoxigenin-labeled msp5 probe. P is the positive control and represents an amplicon of an msp5 plasmid. N is the negative control and represents salivary glands of individual B. microplus or D. andersoni ticks fed on an uninfected calf. Lanes 1 to 20 designate amplicons of individual ticks fed on calf 908, persistently infected with the Puerto Rico strain. A minimum of 150 individual B. microplus and D. andersoni ticks were examined from each feeding on calves with persistent infections with the St. Maries strain or the Puerto Rico strain.