Sympatric western lowland gorillas, central chimpanzees and humans are infected with different trichomonads

Abstract

We investigated intestinal trichomonads in western lowland gorillas, central chimpanzees and humans cohabiting the forest ecosystem of Dzanga-Sangha Protected Area in Central African Republic, using the internal transcribed spacer (ITS) region and SSU rRNA gene sequences. Trichomonads belonging to the genus Tetratrichomonas were detected in 23% of the faecal samples and in all host species. Different hosts were infected with different genotypes of Tetratrichomonas. In chimpanzees, we detected tetratrichomonads from ‘novel lineage 2’, which was previously reported mostly in captive and wild chimpanzees. In gorillas, we found two different genotypes of Tetratrichomonas. The ITS region sequences of the more frequent genotype were identical to the sequence found in a faecal sample of a wild western lowland gorilla from Cameroon. Sequences of the second genotype from gorillas were almost identical to sequences previously obtained from an anorexic French woman. We provide the first report of the presence of intestinal tetratrichomonads in asymptomatic, apparently healthy humans. Human tetratrichomonads belonged to the lineage 7, which was previously reported in domestic and wild pigs and a domestic horse. Our findings suggest that the ecology and spatial overlap among hominids in the tropical forest ecosystem has not resulted in exchange of intestinal trichomonads among these hosts.

Prevalence of intestinal trichomonads in captive non-human primates in China

“…Limited work has been undertaken on trichomonad infection in NHPs and prevalence, genetic diversity, and pathogenic potential are poorly understood. The present study found overall trichomonad prevalence in NHPs to be 11.4% (61/533), lower than findings previously reported in NHPs in North China (46.7%, 28/60) [18], gorillas in the Central African Republic (27.6%, 45/163) [24], wild chimpanzees in Uganda (68.6%, 48/70), and NHPs in Southeastern Brazil (31.3%, 5/16) [9,25]. Differences in prevalence may be due to the influence of multiple risk factors governing infection and sample sizes have generally been small, at fewer than 100 subjects [9,18,25].…”

“…( Table 1 ), and P. hominis and Tetratrichomonas sp. have previously been documented in NHPs [ 2 , 18 , 24 ]. Importantly, P. hominis has a wide range of hosts and has frequently been detected in many mammals including humans, highlighting its zoonotic potential [ 12 , 28 ].…”

Structure of Chimpanzee Gut Microbiomes across Tropical Africa

“…There is a long history of research on parasites in primates ( 65 ), including many studies focused on chimpanzees (e.g., references 51 and 82 ). Until recently, however, parasite surveys used morphology-based identification, and newer sequencing studies have been limited in their geographic breadth or sample size ( 83 – 86 ). As a result, while we have a rich understanding of the presence of certain parasites in certain chimpanzee populations ( 65 ), our understanding of the distribution of parasites lags behind that of bacteria ( 85 , 87 ).…”

“…Previous work has found more closely related primates to have more similar parasite communities ( 86 ), an observation we extend to the subspecies and population level. For example, parasites in the parabasalid Tetratrichomonas genus are prevalent in sympatric chimpanzees, gorillas, and humans, but different species and strains are found among the three species ( 84 ); different lineages within the genus are associated with different hosts, with a high degree of specificity ( 92 ). We report host specificity, at the regional level, in four of five trichomonads.…”

Updated classification of the phylum Parabasalia

“…The ecological relevance of parabasalians is also tied to their role in termite biology: termites are so abundant, and their microbial symbiotic consortia so integral to their metabolism, that they are responsible for a significant amount of greenhouse methane in the atmosphere (Zanne et al., 2022). On the other end of the symbiotic spectrum, the parasitic Trichomonas vaginalis is notorious as the most common sexually transmitted disease in humans (Alsaad, 2022); some of its relatives are pathogenic in other mammals and birds (Amin et al., 2014; Petrželková et al., 2019). Individual parabasalian species have also drawn attention for puzzling and largely unexplored aspects of their biology.…”