Metataxonomic profiles of bacterial and parasitic communities in Amblyomma spp. ticks collected from wildlife in Colombia: Implications for tick-borne diseases.

Abstract

As a tropical country, Colombia hosts a wide range of arthropods that can act as vectors of disease-causing pathogens, particularly those carrying hemopathogens. Ticks play a crucial role in the transmission of zoonotic pathogens, impacting both human and veterinary health. The pathogen load of ticks from wildlife is of particular concern, as it can contribute to the spillover of infectious agents to domestic animals and humans, highlighting the need for surveillance and control strategies to mitigate emerging tick-borne diseases. Therefore, this study aimed to determine the presence of microorganisms in ticks collected from wildlife in Antioquia (Colombia) through bioinformatic analysis. A prospective, cross-sectional, random, non-probabilistic, convenience-based study involving tick collection from animals in three different zones of Antioquia was conducted. Initially, vertebrate species were morphologically characterized via taxonomic keys and identification guides for amphibians, reptiles, birds, and mammals. Ticks were manually collected from these animals and preserved in absolute ethanol for later taxonomic identification. Genomic DNA was then extracted, and the resulting reads were processed through bioinformatic analysis, achieving taxonomic classification within DNA libraries of gram-positive bacteria, gram-negative bacteria, and parasites. Additionally, descriptive statistics were calculated for all variables of interest at the animal level (e.g., genus, species, sex, and age group, when applicable) and study zone. A total of 570 ticks, predominantly Amblyomma spp., were obtained from 46 host animals. Ticks from lizards presented the highest bacterial richness and diversity (based on 16S gDNA), whereas ticks from amphibians presented the lowest. Proteobacteria dominated most samples, as shown by taxonomic composition at the phylum, family, and genus levels. Ticks collected from mammals displayed lower diversity and richness than those collected from reptiles. For parasitic communities (18S gDNA), dominant eukaryotes were identified in ticks from mammals, excluding host-related taxa. Overall, lizard-associated ticks presented the most complex microbial diversity, whereas amphibian ticks were less diverse, highlighting the significant variation in microbial and parasitic communities across host species. This study highlights the microbial diversity of ticks from wild hosts in Colombia, focusing on the dominance of Francisella, Rickettsia, Aspergillus, and Penicillium. These findings underscore the need for further research on their ecological roles, transmission dynamics, and potential health risks, aiming to inform strategies to mitigate tick-borne diseases.