Pathogenic Eukaryotes in Gut Microbiota of Western Lowland Gorillas as Revealed by Molecular Survey

Abstract

Although gorillas regarded as the largest extant species of primates and have a close phylogenetic relationship with humans, eukaryotic communities have not been previously studied in these populations. Herein, 35 eukaryotic primer sets targeting the 18S rRNA gene, internal transcribed spacer gene and other specific genes were used firstly to explore the eukaryotes in a fecal sample from a wild western lowland gorilla (Gorilla gorilla gorilla). Then specific real-time PCRs were achieved in additional 48 fecal samples from 21 individual gorillas to investigate the presence of human eukaryotic pathogens. In total, 1,572 clones were obtained and sequenced from the 15 cloning libraries, resulting in the retrieval of 87 eukaryotic species, including 52 fungi, 10 protozoa, 4 nematodes and 21 plant species, of which 52, 5, 2 and 21 species, respectively, have never before been described in gorillas. We also reported the occurrence of pathogenic fungi and parasites (i.e. Oesophagostomum bifurcum (86%), Necator americanus (43%), Candida tropicalis (81%) and other pathogenic fungi were identified). In conclusion, molecular techniques using multiple primer sets may offer an effective tool to study complex eukaryotic communities and to identify potential pathogens in the gastrointestinal tracts of primates.

Anaerobic Fungi in Gorilla (Gorilla gorilla gorilla) Feces: an Adaptation to a High-Fiber Diet?

“…Similar to the findings of a previous study (Hamad et al, 2014), we detected several Ascomycota and Basidiomycota strains in our gorilla samples. There is no concordance on the species level between Ascomycota strains we obtained and clones isolated by Hamad et al (2014). However, four (Eurotiales, Hypocreales, Saccharomycetales, and Capnodiales) of six genera found by Hamad and colleagues are also present in our samples.…”

“…Our results for Basidiomycota differ greatly from previously isolated strains in gorillas. While we isolated only four strains, it seems that the diversity of Basidiomycota in the colonic fungal community of gorillas is actually far greater (Hamad et al, 2014).…”

“…While some of the Basidiomycota strains detected in gorillas are human pathogens, a few of the identified Ascomycota, namely members of the order Saccharomycetales that are usually associated with plants, possess fermentative capacities (Hamad et al, 2014). It is, however, unclear whether these aerobic fungi constitute transients passing through the enteric tract with food particles or if they are residents and part of the gut microbiome with benefits for the host.…”

“…Many early studies focused on specific mycotic infections (reviewed in Migaki et al, 1982), and a more recent study targeted a broader diversity of enteric fungi in Western lowland gorillas (Gorilla gorilla gorilla). This molecular survey of pathogenic eukaryotes detected 52 fungal species, all belonging to the taxa Ascomycota and Basidiomycota (Hamad et al, 2014). However, no study has yet investigated Neocallimastigomycetes in primates, even though there is good reason to hypothesize that some primates harbour these fungi.…”

Molecular Epidemiology of Blastocystis sp. in Various Animal Groups from Two French Zoos and Evaluation of Potential Zoonotic Risk

“…NMASTs I to V and NMAST VII represented reptilian clusters, while NMAST VI was composed only of insect isolates and NMAST VIII of both amphibian and reptilian isolates. Curiously, an additional isolate identified through the microbiota analysis of a wild western lowland gorilla [42] emerged within the reptilian NMAST II, suggesting highly probable accidental contamination of the primate with reptile feces in its natural environment. Concerning the 9 sequences obtained in the present study and exhibiting low identity with the homologous sequences available in databases, 2 of them, ZLB27 from aldabra tortoise and ZLC1 clone 2 from spur-thighed tortoise, grouped together (BP and BPP of 99% and 1, respectively) and clustered with two representatives of the NMAST II clade (KINIX2 and GECA2) with BP and BPP of 63% and 0.99, respectively.…”