Epidemiological study of ticks collected from the northern tamandua (Tamandua mexicana) and a literature review of ticks of Myrmecophagidae anteaters.

The family Myrmecophagidae contains three anteater species: Tamandua mexicana (Saussure, 1860), Tamandua tetradactyla (Linnaeus, 1758) and Myrmecophaga tridactyla (Linnaeus, 1758). These American anteater species currently face many conservation threats, among which road traffic accidents stand out. Parasitic studies on this family are scarce, and some of them include records of ectoparasites. Specifically for northern tamandua (T. mexicana), there is a lack of studies at population level. The objectives of the present research were to carry out an epidemiological study of tick species and its abundance on road-killed northern anteater specimens and, moreover, to perform a literature review of ticks collected from anteaters of Myrmecophagidae family. Five tick species were identified, including four Amblyomma spp. and Rhipicephalus sanguineus sensu lato, on 23 road-killed anteaters. Tick infestation prevalence was 43% (10/23), with a median tick infestation intensity of 3.5 per anteater (interquartile range 1-13.7). The bibliographic review highlighted the existence of twenty-nine ixodid species recorded on the three anteater species from 14 countries, mainly Brazil. The most common tick species on the Myrmecophagidae family are Amblyomma nodosum, A. calcaratum, A. cajennense sensu lato and A. auricularium. Some of these ixodids were also described as vectors of pathogens. Further studies are needed to evaluate the impact of ticks on anteater fitness, and to assess the role of these mammals as reservoirs of vector-borne diseases.

The role of sloths and anteaters as Leishmania spp. reservoirs: a review and a newly described natural infection of Leishmania mexicana in the northern anteater.

For years, mammals of the order Pilosa have been considered Leishmania reservoirs. But while most studies have focused on sloth species, anteaters have been overlooked, and in many Leishmania endemic countries like Mexico, no studies have been carried out. The aims of this work were to identify the presence of Leishmania spp. in tissue samples from road-killed northern tamanduas (Tamandua mexicana), using PCR amplification and sequencing of ITS1 DNA, and to discuss the role of Pilosa mammals as reservoirs of Leishmania based on available scientific records. This is the first study that identifies Leishmania in T. mexicana, from 1 of 16 individuals analyzed, so the estimated prevalence (CI 95%) of infection was 6.3% (0.3-27.2). Amplified sequence exhibited a 98.9% (727/735) similarity with L. mexicana, and phylogenetic analysis grouped the species in the L. mexicana-amazonensis cluster. The literature review revealed 241 cases of Leishmania spp. infection among 1219 Pilosa mammals evaluated, with prevalence between studies ranging from 3.5% in the brown-throated three-toed sloth (Bradypus variegatus) to 78% in the Hoffman's two-toed sloth (Choloepus hoffmanni). Current scientific information indicates that C. hoffmanni sloths are reservoirs of Leishmania, and further studies are needed in order to clarify if other Pilosa species play a role in Leishmania transmission.

Clarifying the Cryptic Host Specificity of Blastocystis spp. Isolates from Alouatta palliata and A. pigra Howler Monkeys.

Although the presence of cryptic host specificity has been documented in Blastocystis, differences in infection rates and high genetic polymorphism within and between populations of some subtypes (ST) have impeded the clarification of the generalist or specialist specificity of this parasite. We assessed the genetic variability and host specificity of Blastocystis spp. in wild howler monkeys from two rainforest areas in the southeastern region of Mexico. Fecal samples of 225 Alouatta palliata (59) and A. pigra (166) monkeys, belonging to 16 sylvatic sites, were analyzed for infection with Blastocystis ST using a region of the small subunit rDNA (SSUrDNA) gene as a marker. Phylogenetic and genetic diversity analyses were performed according to the geographic areas where the monkeys were found. Blastocystis ST2 was the most abundant (91.9%), followed by ST1 and ST8 with 4.6% and 3.5%, respectively; no association between Blastocystis ST and Alouatta species was observed. SSUrDNA sequences in GenBank from human and non-human primates (NHP) were used as ST references and included in population analyses. The haplotype network trees exhibited different distributions: ST1 showed a generalist profile since several haplotypes from different animals were homogeneously distributed with few mutational changes. For ST2, a major dispersion center grouped the Mexican samples, and high mutational differences were observed between NHP. Furthermore, nucleotide and haplotype diversity values, as well as migration and genetic differentiation indexes, showed contrasting values for ST1 and ST2. These data suggest that ST1 populations are only minimally differentiated, while ST2 populations in humans are highly differentiated from those of NHP. The host generalist and specialist specificities exhibited by ST1 and ST2 Blastocystis populations indicate distinct adaptation processes. Because ST1 exhibits a generalist profile, this haplotype can be considered a metapopulation; in contrast, ST2 exists as a set of local populations with preferences for either humans or NHP.