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ARS Home » Pacific West Area » Pullman, Washington » Animal Disease Research Unit » Research » Publications at this Location » Publication #425388
Research Project: Control Strategies for Bovine Babesiosis

Location: Animal Disease Research Unit

Title: Identification of a tick midgut protein involved in Babesia bovis infection of female Rhipicephalus microplus ticks

Author
item IZAGUIRRE, SADIE - Washington State University
item CAPELLI-PEIXOTO, JANAINA - Washington State University
item VIMONISH, RUBIKAH - Washington State University
item Poh, Karen
item Davis, Sara
item PELTIER, KIERRA - Washington State University
item BRAYTON, KELLY - Washington State University
item Taus, Naomi
item Chung, Chungwon
item Ueti, Massaro

Submitted to: Microorganisms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/19/2025
Publication Date: 7/22/2025
Citation: Izaguirre, S., Capelli-Peixoto, J., Vimonish, R., Poh, K.C., Davis, S.K., Peltier, K., Brayton, K.A., Taus, N.S., Chung, C.J., Ueti, M.W. 2025. Identification of a tick midgut protein involved in Babesia bovis infection of female Rhipicephalus microplus ticks. Microorganisms. 13(8). Article 1713. https://doi.org/10.3390/microorganisms13081713.
DOI: https://doi.org/10.3390/microorganisms13081713

Interpretive Summary: Some ticks transmit the parasite, Babesia bovis, to cattle, causing bovine babesiosis. Methods to control this disease are limited. Disrupting essential interactions between the tick and B. bovis is one strategy to reduce parasite transmission. In this study, we identified a previously uncharacterized protein, putative conserved secreted protein (Pcsp), that is increased in the tick during B. bovis infection. We silenced the Pcsp gene and examined the effects on both tick fitness and B. bovis infection. Our results showed a slight (20%) reduction in recovery of engorged female ticks. More importantly, there was a significant decrease in parasite-infected females. Only 15% of adults acquired the infection compared to over 80% in controls. We also observed a significant reduction in vertical transmission to progeny larvae. These findings suggest that Pcsp is critical for B. bovis infection of ticks and could be a target for transmission-blocking strategies.

Technical Abstract: Rhipicephalus microplus plays a crucial role as a biological vector in transmitting Babesia bovis, the causative agent of bovine babesiosis. Unfortunately, the available strategies for controlling B. bovis are limited, posing significant challenges for both animal health and livestock management. The infection of the tick's midgut is essential first step for the transmission cycle of B. bovis, yet these interactions remain largely understudied. In this study, we identified an uncharacterized protein, a putative conserved secreted protein (Pcsp), that is twofold upregulated during B. bovis infection. We hypothesized that Pcsp is essential for B. bovis infection in the tick midgut. To test this hypothesis, we silenced the Pcsp gene using RNA interference and examined its effects on both tick fitness and B. bovis infection. Our results indicated that silencing the Pcsp gene does not impact tick fitness, except for the recovery of engorged female ticks, which exhibited a 20% reduction in fitness. Importantly, we found that suppressing the Pcsp gene led to a significant decrease in the number of replete female ticks infected with B. bovis kinetes, with only 15% of adult females acquiring the infection compared to over 80% in the control groups. We also observed a significant reduction in vertical transmission to progeny larvae. These findings suggest that Pcsp may be critical for midgut infection by B. bovis and could serve as a promising target for future transmission-blocking strategies.