Emerging zoonotic infectious diseases pose a serious threat to global health. This is especially true in relation to the great apes, whose close phylogenetic relationship with humans results in a ...high potential for microorganism exchange. In this review, we show how studies of the microorganisms of wild great apes can lead to the discovery of novel pathogens of importance for humans. We also illustrate how these primates, living in their natural habitats, can serve as sentinels for outbreaks of human disease in regions with a high likelihood of disease emergence. Greater sampling efforts and improvements in sample preservation and diagnostic capacity are rapidly improving our understanding of the diversity and distribution of microorganisms in wild great apes. Linking non-invasive diagnostic data with observational health data from great apes habituated to human presence is a promising approach for the discovery of pathogens of high relevance for humans.
Fine-scale knowledge of the changes in composition and function of the human gut microbiome compared that of our closest relatives is critical for understanding the evolutionary processes underlying ...its developmental trajectory. To infer taxonomic and functional changes in the gut microbiome across hominids at different timescales, we perform high-resolution metagenomic-based analyzes of the fecal microbiome from over two hundred samples including diverse human populations, as well as wild-living chimpanzees, bonobos, and gorillas. We find human-associated taxa depleted within non-human apes and patterns of host-specific gut microbiota, suggesting the widespread acquisition of novel microbial clades along the evolutionary divergence of hosts. In contrast, we reveal multiple lines of evidence for a pervasive loss of diversity in human populations in correlation with a high Human Development Index, including evolutionarily conserved clades. Similarly, patterns of co-phylogeny between microbes and hosts are found to be disrupted in humans. Together with identifying individual microbial taxa and functional adaptations that correlate to host phylogeny, these findings offer insights into specific candidates playing a role in the diverging trajectories of the gut microbiome of hominids. We find that repeated horizontal gene transfer and gene loss, as well as the adaptation to transient microaerobic conditions appear to have played a role in the evolution of the human gut microbiome.
Treponema pallidum infections causing yaws disease and venereal syphilis are globally widespread in human populations, infecting hundreds of thousands and millions annually respectively; endemic ...syphilis is much less common, and pinta has not been observed in decades. We discuss controversy surrounding the origin, evolution and history of these pathogens in light of available molecular and anthropological evidence. These bacteria (or close relatives) seem to affect many wild African nonhuman primate (NHP) species, though to date only a single NHP Treponema pallidum genome has been published, hindering detection of spillover events and our understanding of potential wildlife reservoirs. Similarly, only ten genomes of Treponema pallidum infecting humans have been published, impeding a full understanding of their diversity and evolutionary history. Research efforts have been hampered by the difficulty of culturing and propagating Treponema pallidum. Here we highlight avenues of research recently opened by the coupling of hybridization capture and next-generation sequencing. We present data generated with such an approach suggesting that asymptomatic bones from NHP occasionally contain enough treponemal DNA to recover large fractions of their genomes. We expect that these methods, which naturally can be applied to modern biopsy samples and ancient human bones, will soon considerably improve our understanding of these enigmatic pathogens and lay rest to old yet unresolved controversies.
Aims
The aim of this work was to identify a protein which can be used for specific detection of antibodies against Bacillus cereus biovar anthracis (Bcbva), an anthrax‐causing pathogen that so far ...has been described in African rainforest areas.
Methods and Results
Culture supernatants of Bcbva and classic Bacillus anthracis (Ba) were analysed by gel electrophoresis, and a 35‐kDa protein secreted only by Bcbva and not Ba was detected. The protein was identified as pXO2‐60 by mass spectrometry. Sequence analysis showed that Ba is unable to secrete this protein due to a premature stop codon in the sequence for the signal peptide. Immunization of five outbred mice with sterile bacterial culture supernatants of Bcbva revealed an immune response in ELISA against pXO2‐60 (three mice positive, one borderline) and the protective antigen (PA; four mice). When supernatants of classic Ba were injected into mice or human sera from anthrax patients were analysed, only antibodies against PA were detected.
Conclusions
In combination with PA, the pXO2‐60 protein can be used for the detection of antibodies specific against Bcbva and discriminating from Ba.
Significance and Impact of the Study
After further validation, serological assays based on pXO2‐60 can be used to perform seroprevalence studies to determine the epidemiology of B. cereus bv anthracis in affected countries and assess its impact on the human population.
Summary
Staphylococcus aureus is a bacterium that colonizes and infects both humans and animals. As little is known about the phenotypic and molecular characteristics of S. aureus from wild animals ...in sub‐Saharan Africa, the objective of the study was to characterize S. aureus isolates from wildlife and to analyse if they differed from those found among humans. The resistance to penicillin was low in S. aureus isolates from non‐human primates (2.9%). Phylogenetic analysis based on the concatenated sequences from multilocus sequence typing revealed two highly divergent groups of isolates. One group was predominated by S. aureus that belonged to known human‐related STs (ST1, ST9 and ST601) and mainly derived from great apes. A second clade comprised isolates with novel STs. These isolates were different from classical human S. aureus strains and mainly derived from monkeys. Our findings provide the basis for future studies addressing the inter‐ and intra‐species transmission of S. aureus in Africa.
Commercial hunting and habitat loss are major drivers of the rapid decline of great apes
1. Ecotourism and research have been widely promoted as a means of providing alternative value for apes and ...their habitats
2. However, close contact between humans and habituated apes during ape tourism and research has raised concerns that disease transmission risks might outweigh benefits
3–7. To date only bacterial and parasitic infections of typically low virulence have been shown to move from humans to wild apes
8, 9. Here, we present the first direct evidence of virus transmission from humans to wild apes. Tissue samples from habituated chimpanzees that died during three respiratory-disease outbreaks at our research site, Côte d'Ivoire, contained two common human paramyxoviruses. Viral strains sampled from chimpanzees were closely related to strains circulating in contemporaneous, worldwide human epidemics. Twenty-four years of mortality data from observed chimpanzees reveal that such respiratory outbreaks could have a long history. In contrast, survey data show that research presence has had a strong positive effect in suppressing poaching around the research site. These observations illustrate the challenge of maximizing the benefit of research and tourism to great apes while minimizing the negative side effects.
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