Morphological and molecular confirmation of Ornithodoros hasei (Schulze, 1935) (Acari: Argasidae) in Colombia

A large number of tick species are proven vectors for the transmission of bacteria, protozoa, and viruses. Soft ticks (Acari: Argasidae) in South America have been found to be the most frequent carriers of borreliae of the relapsing fever group (RFG); however, there are several information gaps specially on the taxonomy and distribution of some tick species. Here, we used light microscopy, scanning electron microscopy, and PCR amplification of a fragment of the mitochondrial 16S rRNA gene to evaluate 174 larvae of Ornithodoros (Argasidae) collected from three bat species (Eptesicus orinocensis, Molossus rufus and Noctilio albiventris) in the Orinoquia Region of Colombia. The morphological and molecular results confirmed that all the analyzed larvae corresponded to Ornithodoros hasei. Comparisons of mitochondrial 16S rDNA sequences showed low genetic divergence (0% - 0.3%) between larvae of the Department of Arauca in the Orinoquia Region and higher genetic divergence (3.4 - 4.7%) in sequences from other American countries. Our work represents the most recent collection of this species in Colombia and provides a molecular evaluation for the first time. Moreover, a new association of O. hasei with bats such as E. orinocensis is documented. Considering the wide distribution of O. hasei in the American Continent, and its putative role as vector for Borrelia, integrative studies that involve morphological, morphometric, molecular data and experimental crosses are needed to determine if the higher genetic distances are associated with cryptic speciation, as detected in other tick complexes, or represent genetic divergences among geographically different populations of O. hasei.

Automated summary

This study conducted morphological and molecular analysis on 174 larvae of Ornithodoros hasei collected from three bat species in the Orinoquia Region of Colombia. The results confirmed the species identification and showed low genetic divergence between larvae from the Arauca Department and higher genetic divergence with larvae from other American countries. This work contributes to the understanding of the distribution and potential role of O. hasei as a vector for Borrelia.