Genetic Characterization of Toxocara vitilorum in Turkey by Mitochondrial Gene Markers (cox1)

Abstract

Background: Toxocara vitulorum is a involved in the Ascaridoidea family and is a large roundworm with a semi translucent, soft body surface and pinkish color. Female worms measure 8-30cm in length, male worms 6-25cm. The major hosts of T.vitulorum are buffalo (Bubalus bubalis) and cattle (Bos species) in the humid tropics of Asia, Africa and South America. The diagnosis of T. vitulorum infections is usually made by observing characteristic eggs in routine fecal examination. Serological methods are also used to diagnose Toxocariasis. However, in recent years, PCR, a new generation molecular diagnostic method, has been used. The genetic structure of T. vitulorum is little known compared with data available from other parasites. The present sutudy was designed to determine the T. vitulorum isolates by the genetic characterization of the mitochondrial cytochrome c oxidase subunit I (cox1) gene.Materials, Methods & Results: Adult worms were collected from the feces of two calves (East Anatolian Red) during visits to the clinic at the Department of Internal Medicine of Van Yuzuncu Yil University, Faculty of Veterinary Medicine. Worms were washed thoroughly in 0.85 % saline to remove any debris and fixed into 70 % ethanol. After repeated and thoroughly washing the specimens, total genomic DNA of parasite extraction was performed be employing DNA extraction reagent kit (Thermo, GeneJET Genomic DNA Purification Kit) according to manufacturer’s recommendations. After DNA amplification, a 446 bp fragment of cox1 of T. vitulorum were obtained in all three isolates. All generated sequences were registered in GenBank database with accession numbers including MG905159, MG911729 and MG911730. The cox1 of T. vitulorum examined differed from another two isolates extracted from Germany beef cattle (KY313642.1) and Sri Lanka buffalo calf (FJ664617.1) at NCBI database. The MEGA 7 software was employed to calculate intra-species distance and similarity. The intra-species distance rate and similarity among the isolates were 0.005 and 99.995%, respectively. The cox 1 sequence of T. vitulorum did not differ from an isolate from Germany, but differed more from isolate from Sri Lanka. The phylogenetic tree that was constructed using the Neighbor-Joining (NJ) method. Bootstrap support (Bp) for ML trees was calculating 1000 bootstrap replicates. This results indicate that both the different species of Toxocara are host-specific and each member of the genus Toxocara spp. has a different about the molecular sequences. We used the phylogenies from the Maximum Parsimony (MP) method to construct another phylogenetic tree based on the cox1 (mtDNA) gene. The results again display that the cattle-calves (East Anatolian Red) isolates from Turkey homology with that obtained from the Germany beef cattle (accession no. KY313642.1).Discussion: The genetic analysis of parasites is a crucial factor in terms of determining epidemiology and the control parasitic diseases of humans and animals. Toxocara vitulorum is the most common gastrointestinal helmints infecting ruminants particularly in tropical regions. Phylogenetic analysis revealed that T. vitulorum is 100% homology with related to sequence of T. vitulorum from Germany. The characterization of cox1 region can provides a foundation for accurate identification of some helminth species using PCR. Even though the small sample size, the obtained results might provide useful information for further phylogenetic studies on the family Ascaridae.

Prevalence and Molecular Characterization of Toxocara cati Infection in Feral Cats in Alexandria City, Northern Egypt

“…Comparison of the newly obtained nad1 sequence with other sequences of Toxocara on Genbank through BLAST confirms the isolate as T. cati , which clusters on the phylogenetic tree in one group with isolates from other areas of the world, proving that nad1 gene mtDNA can be used as a genetic marker to identify and discriminate among Toxocara spp. Our successful amplification and sequencing of nad1 gene T. cati supported previous work ( 14 , 18 , 19 ) suggesting nad1 can be used as a gene marker for Toxocara . Molecular based methods are of great value to identify parasite species with certainty.…”

The Complete Mitogenome of Toxocara vitulorum: Novel In-Sights into the Phylogenetics in Toxocaridae

“…Additionally, the mitochondrial (mt) DNA has also attracted more and more attention and proven more suitable than the ribosomal sequences for species identification due to its matrilineal inheritance, lack of recombination, and rapid rate of evolution [ 24 , 25 , 26 , 27 ]. For example, mt genes atp6, nad1, and cox1 were also used to identify T. vitulorum [ 9 , 23 , 28 , 29 ]. Nevertheless, compared with single gene or partial genetic genes, analysis based on the full mitogenome provides particularly effective information in the distinctiveness of species and interspecies sequence variability and therefore could yield novel opinions into evolutionary and phylogenetic-based analyses of nematode parasites.…”

EjFAD8 Enhances the Low-Temperature Tolerance of Loquat by Desaturation of Sulfoquinovosyl Diacylglycerol (SQDG)

“…Multiple sequence comparisons were performed using Clustal X calibrated sequences and displayed by Jalview software; phylogenetic analysis was constructed by MEGA software under the neighbor-joining method with 1000 bootstrap repeats [ 46 ]; other sequences were obtained from NCBI ( (accessed on 11 July 2022)), and the gene IDs are listed in Table S2 .…”