Nematode diversity in Mastomys rodents (Rodentia: Muridae) across a wildlife-human/domestic animal interface and molecular characterization of Trichuris species from M. natalensis

Abstract

Nematodes comprise many species with diverse life histories and zoonotic potential. Globally, over 10,500 nematode species were reported in mammals, particularly rodents. In South and southern Africa, data on nematode diversity in native rodent populations remains limited. The current study aimed to address this gap by reporting nematode diversity in two Mastomys species (Mastomys coucha and M. natalensis) and conducting molecular analysis of an unidentified Trichuris species recovered from M. natalensis. A total of 68 M. natalensis and 27 M. coucha rodents were trapped across a wildlife-human/domestic animal interface in South Africa during October 2020. Gastrointestinal nematodes were recovered and morphologically identified. Morphometric assessment and Sanger sequencing of mitochondrial markers, internal transcribed spacer 1 and 2 (ITS1, ITS2) and cytochrome b (cytb) were performed on the unidentified Trichuris species. In total, 46 nematodes were identified representing two genera, Trichuris and Abbreviata, with an overall prevalence of 21.1%. Trichuris sp. dominated in M. natalensis and anthropogenically transformed habitats, while Abbreviata sp. was associated with M. coucha in the natural habitats. Morphometrics of the unidentified Trichuris sp. aligned with reported ranges for the genus, while phylogenetic analyses revealed a novel clade distinct from known Trichuris spp. The current study emphasises the importance of integrating morphometric and molecular analyses for accurate nematode identification. The potential public health threat of the novel Trichuris sp. in M. natalensis needs further investigation, given the zoonotic capability of Trichuris spp. and the proximity of rodents to humans in the study area.