An Overview of Current Knowledge onin vitro BabesiaCultivation for Production of Live Attenuated Vaccines for Bovine Babesiosis in Mexico

The instrumentation of thein vitroculture system has allowed researchers to learn more about the metabolic and growth behavior ofBabesiaspp. The various applications forin vitrocultivation ofBabesiainclude obtaining attenuated strains for vaccination or pre-munition, the selection of pure lines with different degrees of virulence, studies on biological cloning, ultrastructure, antigen production for diagnostics, drug sensitivity assessments, and different aspects of parasite biology. Although there are different types of vaccines that have been tested against bovine babesiosis, so far, the only procedure that has offered favorable results in terms of protection and safety has been the use of live attenuated vaccines. In countries, such as Australia, Argentina, Brazil, Uruguay and Israel, this type of vaccine has been produced and used. The alternative to live vaccines other than splenectomized calf-derived biological material, has been thein vitrocultivation ofBabesia bovisandB. bigemina. The development ofin vitroculture ofBabesiaspp. strains in a defined medium has been the basis for the initiation of a source of parasites and exoantigens for a variety of studies on the biochemistry and immunology of babesiosis. The use of live immunogens from attenuated strains derived fromin vitroculture is highlighted, which has been proposed as an alternative to control bovine babesiosis. In several studies performed in Mexico, this type of immunogen applied to susceptible cattle has shown the induction of protection against the experimental heterologous strain challenge with both,Babesia-infected blood and animal exposure to confrontations on tick vector-infested farms. The combination of transfection technologies and thein vitroculture system as integrated methodologies would eventually give rise to the generation of genetically modified live vaccines. However, a greater challenge faced now by researchers is the large-scale cultivation ofBabesiaparasites for mass production and vaccine distribution.