Intestinal parasites infecting free-ranging primates in Colombia: Morphological and molecular evidence

Intestinal protozoan and metazoan parasites of public health concern have been found infecting non-human primates (NHPs). Since zoonotic parasite transmission can be linked to ecosystem transformation due to close contact between human and NHPs, this study aimed to morphologically identify intestinal parasites infecting NHPs living in seven forest fragments in Colombia and to molecularly characterise selected parasite taxa of zoonotic interest (Giardia sp. and Ascaris sp.). Building on and updating previous parasite surveys on free-ranging platyrrhines, 212 faecal samples were collected from wild Alouatta seniculus, Ateles hybridus, Aotus griseimembra, Cebus versicolor, Saimiri cassiquiarensis, and Sapajus apella. Flotation and faecal smears were performed in order to identify parasites based on morphological characteristics. Samples microscopically classified as positive for Giardia sp. and Ascaris sp. were then processed for molecular characterisation. Amplification of the triosephosphate isomerase (TPI) and the 18S genes was done for Giardia sp., while for Ascaris sp. a PCR-RPLF of the entire ITS region was carried out. About 96% of the samples were positive for intestinal parasites, including: protozoans (Blastocystis sp., Balantidium sp., Dientamoeba fragilis-like, Entamoeba sp., Giardia sp., Eimeria sp.), nematodes (Ascaris sp., strongyliform larvae, Trypanoxyuris sp., Ancylostomatidae), trematodes (Controrchis sp., Trematoda), cestodes (Hymenolepis sp., Cestoda), and acanthocephalans. By microscopy, the prevalence of Giardia sp. and Ascaris sp. was 16.5% and 0.9%, respectively. Later on, Giardia duodenalis (Assemblages A and B) and Ascaris lumbricoides were identified through molecular techniques. This study provides new information of intestinal parasites infecting free-ranging NHPs exposed to anthropogenic disturbance. The finding of parasites with zoonotic potential suggests epidemiological implications in NHP conservation and human health, at the human-NHP interface.