系统发生学与进化生物学杂志

Molecular Characterization and Phylogenetic Analysis of Trypanosoma evansi from Local and Imported Camels in Egypt

Abstract

Safaa M. Barghash, Ahmed M. Darwish and Tarek R. Abou-ElNaga

Trypanosoma evansi, the agent of trypanosomiasis commonly known as Surra or Guffar, is regarded as one of the most economically important animal parasitic pathogen affecting livestock in Egypt. The current study aims to discuss genetic characterization and phylogenetic analysis of Trypanosoma isolates from local and imported naturally infected camels in Egypt. The study was initially started with parasitological and molecular surveillance on 411 native and 117 imported camels by using PCR- RoTat 1.2 VSG gene targeting 205 bp. Further, the molecular characterization and sequencing were achieved on four positive samples using PCR-TR3/TR4 primers that derived from a trypanosome-specific repetitive nucleotide sequence fragment. Product sequences were aligned against the corresponding GenBank sequences of known isolates of T. evansi and subjected to phylogenetic analysis. Results revealed that T. evansi was present in 66.67% and 74.36% of the local and imported camels respectively, regardless of age and sex factors. Basic Local Alignment Search Tool (BLAST) data of the obtained PCR TR3/TR4 gene sequences revealed that they corresponded to those of T. evansi, with the homology of 93% to 99%. Phylogenetic and molecular analyses of this gene showed that three genotypes of T. evansi in Egypt are present showed two common SNPs (G136A and G189T) in all samples, two SNPs in ISM and ISD (C3T and A207G) and six SNPs in HSA (T12C, C14T, T15C, G19C, C21G, and G22C). We conclude that T. evansi is described as presenting genotype variability among its isolates according to geographical distribution in Egypt.