Influence of increased temperature on Anaplasma marginale Theiler in the gut of Dermacentor andersoni stiles.
Three splenectomized dairy calves were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor andersoni Stiles nymphs. One month after molting, groups of adult ticks were incubated at 37 C for 0, 1.5, 2.5, and 7 days. Gut homogenates were made from ticks representing each incubation period. Twenty-four susceptible, splenectomized dairy calves were each inoculated IV with a gut homogenate extracted from 50 adult ticks and monitored for patent A marginale infection. The prepatent periods were determined and used as a measure of infectivity. Gut homogenates made from ticks that had been incubated for 2.5 days produced infections with the shortest prepatent periods, an average of 28.5 days among 3 trials.
D000709:Anaplasma / Q000254:growth & development / Q000472:pathogenicity*; D000712:Anaplasmosis / Q000635:transmission; D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D002417:Cattle; D002418:Cattle Diseases / Q000635:transmission; D003870:Dermacentor / Q000382:microbiology*; D005260:Female; D013156:Splenectomy / Q000662:veterinary; D013696:Temperature; D013987:Ticks / Q000382:microbiology*; D014774:Virulence