Neglected strongylid nematodes: Metabarcoding reveals hidden transmission patterns between great apes and humans

ILÍK, Vladislav, Erich Marquard SCHWARZ, Klára PETRŽELKOVÁ, David MODRÝ, Nikki TAGG and Barbora PAFČO. Neglected strongylid nematodes: Metabarcoding reveals hidden transmission patterns between great apes and humans. In International C. elegans Conference June 21 - 24, 2021 Abstract Book. 2021.

Basic information

• Original name: Neglected strongylid nematodes: Metabarcoding reveals hidden transmission patterns between great apes and humans
• Authors: ILÍK, Vladislav, Erich Marquard SCHWARZ, Klára PETRŽELKOVÁ, David MODRÝ, Nikki TAGG and Barbora PAFČO.
• Edition: International C. elegans Conference June 21 - 24, 2021 Abstract Book, 2021.

Other information

• Type of outcome: Conference abstract
• Confidentiality degree: is not subject to a state or trade secret
• Keywords in English: strongylids; strongylida; nematoda; nematodes; HTS; humans; great apes; sequencing; ITS-2; metabarcoding
• Tags: International impact, Reviewed

Abstract

Strongylid nematodes such as hookworms and nodule worms are important pathogens of terrestrial vertebrates, including humans and non-human primates (NHPs). Despite being more closely related to C. elegans than Pristionchus, strongylids have evolved to live for months or years inside vertebrate hosts, sometimes forming complex communities within those hosts. More than 400 million people are infected with hookworms worldwide. Severe strongylid infections can cause heavy enteritis, intestinal lesions, iron-deficiency anemia, weight loss, stunting in childhood, and adverse birth outcomes. Because the human population and human settlements have rapidly grown in recent decades, people often live close to wild, freeliving animals, which enables mutual pathogen transmission. These cross-species infections can have devastating effects on both sides, as was previously recorded for many diseases of either viral or microbial origin; such infections are especially risky in the case of phylogenetically closely related humans and non-human primates (NHPs). We used metabarcoding DNA amplification and short-read Illumina sequencing to assess the strongylid diversity and infections within humans and great apes (western lowland gorillas and chimpanzees) living in close proximity on the northern border of DJA Faunal Reserve in Cameroon. We analyzed 46 human, 60 western lowland gorilla and 31 central chimpanzee strongylid-positive samples. Great apes exhibited greater strongylid diversity than humans, with Oesophagostomum (nodule worms) and Necator (hookworm) being the most prevalent genera. We also detected rare strongylid taxa and observed several zoonotic strongylid species that were shared between humans and great apes. Our work shows that the human-animal contact can cause mutual exchange of strongylid pathogens, and that complex strongylid nematode communities can be detected time- and cost-efficiently through metabarcoding. Effective conservation efforts in the regions of increased human-animal contact are warranted.