Mutation Characteristics and Phylogenetic Analysis of Five Clinical Isolates.

Leishmaniasis is a neglected tropical disease threatening millions of people worldwide. The emergence of antimony-resistant strains have brought difficulties to the treatment and elimination of leishmaniasis. This study performed genome sequencing, phylogenetic analysis and mutation analysis of five clinical isolates, especially the strain L_HCZ isolated in 2016, which shows strong virulence and antimony resistance. By phylogenetic analysis, four isolates (L_DD8, L_801, L_Liu and L_9044) were identified as , the isolate L_HCZ was identified as and the isolate L_DD8 as a standard strain of . Genome-wide mutation analysis was applied to identify mutations related to the drug resistance and virulence of the newly isolated L_HCZ. Compared with the other four isolates, L_HCZ had the most mutations in genes associated with antimony resistance, including the ABC transporter, ascorbate-dependent peroxidase, gamma-glutamylcysteine synthetase, glucose-6-phosphate 1-dehydrogenase, ATP-binding cassette protein subfamily A and multi-drug resistance protein-like genes. Among the genes associated with virulence, L_HCZ had the most mutations in cysteine peptidase A, cysteine peptidase B, cysteine peptidase C, heat-shock protein 70, gp63, acid phosphatase, kinesin k39, kinesin, phosphoglycan beta 1, amastin-like surface protein and amastin-like proteins. The mutations in L_HCZ might possibly contribute to its antimony resistance and strong virulence in clinical patients. Whole-genome resequencing has exhibited broad application prospects and may be put into clinical use in the future for parasite identifying and epidemiological investigations.