Abstract:
Nematodes comprise of many species with diverse life histories and zoonotic potential.
Understanding the distribution and diversity of nematodes in the commensal rodent genus
Mastomys is crucial for assessing their impact on wildlife and livestock, and potential of zoonotic
disease transmission. The current study investigated the nematode diversity in Mastomys species
rodents in three habitats and characterized the recovered Trichuris sp. using morphometric and
molecular techniques at a wildlife-human/domestic animal interface in the Savanna biome in Mnisi
communal area, Mpumalanga, South Africa. Nematodes were recovered and identified in the
gastrointestinal tracts of 68 M. natalensis and 27 M. coucha rodents which were trapped in crop,
village and natural habitats in the Mnisi communal area in October 2020. Nematodes were
microscopically identified using morphometric measurements. Molecular characterization of
Trichuris sp. was achieved through deoxyribonucleic acid (DNA) extraction, polymerase chain
reaction (PCR), Sanger sequencing and phylogenetic analyses of three genes: internal transcribed
spacers (ITS) 1, ITS 2 and cytochrome B (CytB). Data were analyzed using descriptive statistics,
univariate models, a zero-inflated negative binomial generalized linear model, and a binomial
generalised linear model, to establish the frequency, measures of central tendency and the
relationships between nematode counts or occurrence and predictor variables using R statistical
software. Nematodes were recovered in 20% of the examined rodents, with a total of 46 nematodes
recovered, representing two species: Trichuris sp. (mean abundance of 0.31± 0.22) primarily from
the caecum and Abbreviata sp. (mean abundance of 0.15±0.14) primarily from the stomach.
Almost all the rodents were infected with only one nematode species, while one rodent exhibited
mixed infection of both nematode species. No significant differences (p>0.05) in nematode
prevalence were observed between male and female Mastomys spp. Univariate and multivariable
analysis confirmed a lack of significant differences (p>0.05) in nematode abundance concerning
habitat type, rodent species, and sex. The obtained novel Trichuris sp. ITS1, ITS2 and CytB sequences, clustered in a distinct clade from published sequences, but showing genetic
relationships with known Trichuris spp. The current study emphasizes the importance of
integrating morphometric identification and molecular analysis to accurately categorize Trichuris
spp. and suggests a need for a larger sample size per habitat type in future research on nematode
diversity.
