Journal Article

Description, molecular characteristics and Wolbachia endosymbionts of Onchocerca borneensis Uni, Mat Udin & Takaoka n. sp. (Nematoda: Filarioidea) from the Bornean bearded pig Sus barbatus Müller (Cetartiodactyla: Suidae) of Sarawak, Malaysia

Zainuri, Nur Afiqah, Junker, Kerstin, Labat, Amandine, Agatsuma, Takeshi, Fukuda, Masako, Takaoka, Hiroyuki, Belabut, Daicus Martin, Cheah, Phaik Leng, Low, Van Lun, Azirun, Mohd Sofian, Lefoulon, Emilie, Matsubayashi, Makoto, Mat Udin, Ahmad Syihan, Uni, Shigehiko, Ramli, Rosli, Khan, Faisal Ali Anwarali, Martin, Coralie, Lim, Yvonne Ai-Lian, Uga, Shoji, Saijuntha, Weerachai, Bunchom, Naruemon, Bhassu, Subha, Omar, Hasmahzaiti, Hashim, Rosli

2020

Overview

Background The genus Onchocerca Diesing, 1841 includes species of medical importance, such as O. volvulus (Leuckart, 1893), which causes river blindness in the tropics. Recently, zoonotic onchocercosis has been reported in humans worldwide. In Japan, O. dewittei japonica Uni, Bain & Takaoka, 2001 from wild boars is a causative agent for this zoonosis. Many filarioid nematodes are infected with Wolbachia endosymbionts which exhibit various evolutionary relationships with their hosts. While investigating the filarial fauna of Borneo, we discovered an undescribed Onchocerca species in the bearded pig Sus barbatus Müller (Cetartiodactyla: Suidae). Methods We isolated Onchocerca specimens from bearded pigs and examined their morphology. For comparative material, we collected fresh specimens of O. d. dewittei Bain, Ramachandran, Petter & Mak, 1977 from banded pigs ( S. scrofa vittatus Boie) in Peninsular Malaysia. Partial sequences of three different genes (two mitochondrial genes, cox 1 and 12S rRNA, and one nuclear ITS region) of these filarioids were analysed. By multi-locus sequence analyses based on six genes ( 16S rDNA, ftsZ , dnaA , coxA , fbpA and gatB ) of Wolbachia , we determined the supergroups in the specimens from bearded pigs and those of O. d. dewittei . Results Onchocerca borneensis Uni, Mat Udin & Takaoka n. sp. is described on the basis of morphological characteristics and its genetic divergence from congeners. Molecular characteristics of the new species revealed its close evolutionary relationship with O. d. dewittei . Calculated p-distance for the cox 1 gene sequences between O. borneensis n. sp. and O. d. dewittei was 5.9%, while that between O. d. dewittei and O. d. japonica was 7.6%. No intraspecific genetic variation was found for the new species. Wolbachia strains identified in the new species and O. d. dewittei belonged to supergroup C and are closely related. Conclusions Our molecular analyses of filarioids from Asian suids indicate that the new species is sister to O. d. dewittei . On the basis of its morphological and molecular characteristics, we propose to elevate O. d. japonica to species level as O. japonica Uni, Bain & Takaoka, 2001. Coevolutionary relationships exist between the Wolbachia strains and their filarial hosts in Borneo and Peninsular Malaysia.

• Publisher: BioMed Central,Springer Nature B.V,BMC
• Subject: Aquatic insects / Biological evolution / Biomedical and Life Sciences / Biomedicine / Blindness / Borneo / Cetartiodactyla / Coevolution / Congeners / Coxa / Divergence / DNA / Endosymbionts / Entomology / Ethanol / etiological agents / fauna / Females / Gene sequencing / Genes / Genetic divergence / Genetic diversity / genetic variation / Hogs / Hosts / Indomalayan realm / Infectious Diseases / Japan / Life Sciences / Malayfilaria sofiani / Malaysia / Medical importance / Microbiology and Parasitology / Mitochondria / Morphology / multilocus sequence typing / Nematodes / New species / Nucleotide sequence / Onchocerca / Onchocerca borneensis / Onchocerca dewittei / Onchocerca japonica / Onchocerciasis / Parasites / Parasitology / Physical characteristics / Rivers / rRNA 12S / rRNA 16S / Skin / Suidae / Sus / Sus barbatus / Swine / Tropical environments / Tropical Medicine / Veterinary Medicine/Veterinary Science / Virology / Wolbachia / Zoonoses