INFLUENCE OF INCREASED TEMPERATURE ON ANAPLASMA-MARGINALE THEILER IN THE GUT OF DERMACENTOR-ANDERSONI STILES

  • 1 January 1982
    • journal article
    • research article
    • Vol. 43  (1) , 32-35
Abstract
Three splenectomized dairy calves were inoculated with a Virginia, USA, isolate of A. marginale Theiler and served as an infective source for laboratory-reared D. andersoni Stiles nymphs. At 1 mo. after molting, groups of adult ticks were incubated at 37.degree. 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 i.v. 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 were incubated for 2.5 days produced infections with the shortest prepatent periods, an average of 28.5 days among 3 trials.