First molecular description, phylogeny and genetic variation of Taenia hydatigena from Nigerian sheep and goats based on three mitochondrial genes

Abstract

BackgroundCysticercosis caused by the metacestode larval stage of Taenia hydatigena is a disease of veterinary and economic importance. A considerable level of genetic variation among isolates of different intermediate hosts and locations has been documented. Generally, data on the genetic population structure of T. hydatigena is scanty and lacking in Nigeria. Meanwhile, similar findings in other cestodes like Echinococcus spp. have been found to be of epidemiological importance. Our aim, therefore, was to characterize and compare the genetic diversity of T. hydatigena population in Nigeria based on three mitochondrial DNA markers as well as to assess the phylogenetic relationship with populations from other geographical regions.MethodsIn the present study, we described the genetic variation and diversity of T. hydatigena isolates from Nigerian sheep and goats using three full-length mitochondrial genes: the cytochrome c oxidase subunit 1 (cox1), NADH dehydrogenase subunit 1 (nad1), and NADH dehydrogenase subunit 5 (nad5).ResultsThe median-joining network of concatenated cox1-nad1-nad5 sequences indicated that T. hydatigena metacestodes of sheep origin were genetically distinct from those obtained in goats and this was supported by high FST values of nad1, cox1, and concatenated cox1-nad1-nad5 sequences. Genetic variation was also found to be higher in isolates from goats than from sheep.ConclusionsTo the best of our knowledge, the present study described the genetic variation of T. hydatigena population for the first time in Nigeria using full-length mitochondrial genes and suggests the existence of host-specific variants. The population indices of the different DNA markers suggest that analysis of long mitochondrial DNA fragments may provide more information on the molecular ecology of T. hydatigena. We recommend that future studies employ long mitochondrial DNA sequence in order to provide reliable data that would explain the extent of genetic variation in different hosts/locations and the biological and epidemiological significance.

Molecular Identification of Taenia hydatigena from Sheep in Khartoum, Sudan

“…This result was also con-firmed by the posterior probability (PP) values between the isolates, although a few had PP values < 0.70. This low nodal support value between T. hydatigena species was also recently reported in Nigeria [18]. The nucleotide sequences of cox1 and nad1 genes representing T. hydatigena isolates from the present study were deposited in GenBank under the following accession numbers (cox1: MN114527 and MN114528; nad1: MN 114529-MN114531).…”

“…All haplotypes were separated from each other by no more than a 3-point mutational difference. The number of haplotypes based on the cox1 gene was lower compared to the number of haplotypes (4) reported among a T. hydatigena population of Tanzanian sheep and goats [4] but similar to the number of haplotypes reported in Nigerian sheep [18]. The comparison of the nucleotide sequences from this study with the deposited sequences in the GenBank database yielded no haplotype with 100% identity, which could suggest the presence of unique haplotypes in Sudan and is consistent with previous reports of the existence of geographically distinct species of T. hydatigena [29].…”

“…Meanwhile, comparable data from an African host on the diversity indices of T. hydatigena are lacking [4,17]. However, compared with the recent report from Nigeria [18], the Sudanese T. hydatigena isolates showed lower genetic variation.…”

“…have also confirmed the existence of genetic variation within species [13,14], and in some cases, such variation has been suggested to correlate with pathological differences in different hosts [15,16]. The molecular epidemiology and genetic variation of T. hydatigena in Africa are underinvestigated; however, a few studies in countries such as Nigeria, Egypt and Tanzania have demonstrated nucleotide variation between isolates from sheep, goats, and pigs [4,17,18]. Meanwhile, studies describing the genetic population structure of T. hydatigena in Sudan and how they differ from other geographical regions, as well as the epidemiological significance, are lacking.…”

Correction to: First molecular description, phylogeny and genetic variation of Taenia hydatigena from Nigerian sheep and goats based on three mitochondrial genes

“…Following publication of the original article [1], the authors have flagged that the information in the legend of Fig. 1 is detailed in the wrong order.…”