Incompetence of Vector Capacity of Rhipicephalus bursa to Transmit Babesia aktasi following Feeding on Clinically Infected Goat with High Level of Parasitemia

Abstract

A recent molecular survey revealed a high prevalence of Babesia aktasi in indigenous goats from the Mediterranean region of Türkiye, coinciding with heavy Rhipicephalus bursa infestations. This geographical overlap has raised the possibility that R. bursa may serve as a vector for the parasite. To evaluate the potential of R. bursa to serve as a vector for the parasite, an experimental study was conducted in indigenous goats. An immune-suppressed donor goat was intravenously injected with 15 mL of the cryopreserved B. aktasi stabilate, resulting in severe clinical babesiosis and parasitemia. Subsequently, R. bursa larvae and adults derived from Babesia-free laboratory colonies were allowed to feed on the infected donor goat. After oviposition, engorged female carcasses, representative engorged nymphs, unfed larvae, and adult pools were used for DNA extraction and PCR analysis. No PCR positivity was detected in any of the DNA samples, except for those with engorged female carcasses and nymphs. Three immune-suppressed recipient goats were infested with the unfed immature and mature ticks consuming the blood of a donor infected with B. aktasi. No clinical or parasitological findings were encountered in the recipient for 40 days post-infestation. These findings indicated that R. bursa was not a competent vector for B. aktasi.