Antiparasitic Evaluation of Aquiluscidin, a Cathelicidin Obtained from Crotalus aquilus, and the Vcn-23 Derivative Peptide against Babesia bovis, B. bigemina and B. ovata.

Babesiosis is a growing concern due to the increased prevalence of this infectious disease caused by Babesia protozoan parasites, affecting various animals and humans. With rising worries over medication side effects and emerging drug resistance, there is a notable shift towards researching babesiacidal agents. Antimicrobial peptides, specifically cathelicidins known for their broad-spectrum activity and immunomodulatory functions, have emerged as potential candidates. Aquiluscidin, a cathelicidin from Crotalus aquilus, and its derivative Vcn-23, have been of interest due to their previously observed antibacterial effects and non-hemolytic activity. This work aimed to characterize the effect of these peptides against three Babesia species. Results showed Aquiluscidin's significant antimicrobial effects on Babesia species, reducing the B. bigemina growth rate and exhibiting IC50 values of 14.48 and 20.70 µM against B. ovata and B. bovis, respectively. However, its efficacy was impacted by serum presence in culture, and it showed no inhibition against a B. bovis strain grown in serum-supplemented medium. Conversely, Vcn-23 did not demonstrate babesiacidal activity. In conclusion, Aquiluscidin shows antibabesia activity in vitro and its efficacy is affected by the presence of serum in the culture medium. Nevertheless, this peptide represents a candidate for further investigation of its antiparasitic properties and provides insights into potential alternatives for the treatment of babesiosis.

First molecular evidence of Theileria cervi infection in white-tailed deer (Odocoileus virginianus) in Mexico.

Theileria cervi is a tick-borne protozoan that infects different deer species around the world. Clinical diseases due to Theileria cervi have been reported in white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) in the USA, however, information about this parasite has not been documented in Mexico. Here, blood samples from three white-tailed deer (Odocoileus virginianus) from a region in northeastern Mexico were analyzed by blood smear, PCR, and DNA sequencing. The results confirmed the presence of T. cervi for the first time in white-tailed deer in Mexico.