Metabolism of Babesia parasites in vitro. Glucose and energy metabolism of B. bovis.

The glucose and oxygen consumption, glycolytic ratio, lactate and pyruvate production and change in adenylate energy charge (AEC) and ATP concentration of B strain B. bovis-infected erythrocytes were measured. Although less than 5% of erythrocytes were infected, glucose and oxygen consumption in basal salts solution (BSS) were more than 2.5 times, and pyruvate production 7 times, those of uninfected erythrocytes. The glucose consumption of B. bovis alone was similar to previously reported values for B. rodhaini alone but the glycolytic ratio of B. bovis was less than half that previously reported for B. rodhaini. Pre-incubation concentrations of ATP in B strain B. bovis-infected erythrocytes were significantly lower than in uninfected erythrocytes but increased considerably following incubation in BSS, in contrast to B. rodhaini in which ATP concentrations were previously shown to decrease significantly following incubation in basal salts medium. When monitored every 4 h during 24 h incubation in BSS, the glucose consumption and lactate production of two strains of B. bovis were very similar. The glycolytic ratio of K strain B. bovis in RPMI 1640 medium plus 15% bovine plasma was double that in BSS. Both strains of B. bovis were infective after 24 h incubation in basal medium, in marked contrast to B. rodhaini which had been shown to lose infectivity.