Species identification and phylogenetic analysis of canine Leishmania in Diebu County, Gansu Province / 中华地方病学杂志

ABSTRACT

Objective:To investigate the species types and phylogenetic relationship of canine Leishmania in Diebu County, Gansu Province, so as to provide a basis for exploring new methods of prevention and control of canine visceral leishmaniasis. Methods:DNA was extracted from blood samples of eight asymptomatic Leishmania-infected dogs in Luoda administrative village in Diebu County, Gansu Province. Ribosomal internal transcribed spacer 1 (ITS-1) gene fragments were amplified and isolated by PCR, and then the amplified target fragments were sequenced. The MEGA 7.0 software was used for multiple sequence alignment, and a phylogenetic tree was constructed by neighbor-joining method to analyze the phylogenetic relationship of canine Leishmania in Diebu County, Gansu Province. Results:Fragments of about 320 bp corresponding in size to the target sequence ITS-1 were isolated from all of the eight asymptomatic Leishmania-infected dogs blood samples. ITS-1 sequence alignment showed that the sequence homology between 8 samples and Leishmania infantum MG969403, MN648755 strains was 99.1% - 100.0%; phylogenetic tree showed that all 8 samples were clustered into one branch with Leishmania infantum. Conclusion:Leishmania infantum is identified from all of the eight asymptomatic Leishmania-infected dogs blood samples in Diebu County, Gansu Province.