Observation of a novel Babesia spp. in Eastern Grey Kangaroos (Macropus giganteus) in Australia.

The roles and epidemiological features of tick-borne protozoans are not well elicited in wildlife. Babesia spp. are documented in many domestic animals, including cattle, horses, pigs, dogs and cats.

Attenuation of virulence in an apicomplexan hemoparasite results in reduced genome diversity at the population level.

Background: Virulence acquisition and loss is a dynamic adaptation of pathogens to thrive in changing milieus. We investigated the mechanisms of virulence loss at the whole genome level using Babesia bovis as a model apicomplexan in which genetically related attenuated parasites can be reliably derived from virulent parental strains in the natural host. We expected virulence loss to be accompanied by consistent changes at the gene level, and that such changes would be shared among attenuated parasites of diverse geographic and genetic background.

Viability assays of intra-erythrocytic organisms using fluorescent dyes.

Three intra-erythrocytic tick fever organisms of cattle (Babesia bovis, Babesia bigemina and Anaplasma centrale) were subjected to a range of stressors, including heat, storage over time, specific chemotherapy and cryopreservation. Various stains, both alone and in combination, were used in an attempt to assess viability of these organisms before and after the stressors were applied. Carboxyfluorescein diacetate succinimidyl ester (CFSE) stained live Babesia spp.