Molecular identification of Oesophagostomum spp. from 'village' chimpanzees in Uganda and their phylogenetic relationship with those of other primates.

Narumi Ota,Paula A Pebsworth,Hiroshi Sato,Takanori Kooriyama,Michael A Huffman,Hideo Hasegawa,Matthew R Mclennan

doi:10.1098/rsos.150471

Abstract

Oesophagostomum spp. are parasitic nematodes of mammals, including humans and other primates. To identify species and determine phylogeny, we analysed DNA sequences of adult and larval Oesophagostomum from wild chimpanzees in Bulindi, Uganda, which inhabit degraded forest fragments amid villages. Oesophagostome larvae and/or eggs from baboons in Tanzania and South Africa and from a Japanese macaque were also sequenced. Based on the internal transcribed spacer 2 (ITS2) of nuclear ribosomal DNA and partial cytochrome c oxidase subunit 1 gene (Cox1) of mtDNA, O. stephanostomum and O. bifurcum were identified from chimpanzees. Bulindi is the second locality where molecular detection of O. bifurcum in wild chimpanzees has been made. While most O. stephanostomum had ITS2 genotypes recorded previously, three new genotypes were detected. Among four ITS2 genotypes of O. bifurcum from chimpanzees, one was identical to that from various monkey species in Kibale, Uganda, and baboons from Tanzania and South Africa; another was shared by a baboon from Tanzania. No genotype was identical with that of the cryptic species reported from humans and monkeys in Kibale. Phylogeny based on Cox1 sequences of O. stephanostomum showed locality-dependent clades, whereas those of O. bifurcum formed clades composed of worms from different hosts and localities.

Highlights

Nodular worms, Oesophagostomum spp., are intestinal nematodes of mammals, especially pigs, ruminants and primates
Besides the samples from Uganda chimpanzees, filariform larvae reared from the collected faeces of two yellow baboons (Papio cynocephalus) of Mahale, Tanzania, and one Japanese macaque (Macaca fuscata) from Oita, Japan, and eggs isolated from faeces of two chacma baboons (Papio ursinus) of the Western Cape, South Africa, were analysed
The present results demonstrate that chimpanzees in Bulindi, western Uganda were infected with both O. stephanostomum and O. bifurcum

Summary

Introduction

Oesophagostomum spp., are intestinal nematodes of mammals, especially pigs, ruminants and primates. Oesophagostomum bifurcum is of major human health concern in focally endemic areas of Africa, Ghana and Togo in West Africa, where prevalence can be high [2,3,4]. The infections of these species can cause serious clinical disease (oesophagostomiasis) associated with formation of nodular lesions or abscesses in the intestinal wall of humans and nonhuman primates [1,2,5]. O. stephanostomum and a cryptic oesophagostome species were recently demonstrated molecularly from sympatric humans and non-human primates in Uganda, suggesting occurrence of zoonotic transmission [8,9]. Transmission could be enhanced where humans and great apes share the same habitat, because they are genetically more similar to each other than to other sympatric primate hosts [10]

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