Heartwater DiseaseEhrlichia ruminantiumRickettsiaceaeGoatsSelenomonasTicksEhrlichiaZimbabweTick ControlAntigens, BacterialSheepGram-Negative Anaerobic BacteriaDNA, BacterialCattleSheep DiseasesMolecular Sequence DataArachnid VectorsMethanobrevibacterGoat DiseasesRickettsiaceae InfectionsBase SequenceRumenRickettsial VaccinesAnaplasmaDNA Probes