Investigation and analysis of the genetic diversity of Borrelia burgdorferi in host animals and vector ticks from western Yunnan Province
This study was aimed at understanding the genetic diversity of Borrelia burgdorferi infected by host animals and vector ticks in the western region of Yunnan prov-ince,to provide a basis to characterize epidemic strains or geno-types in this region.Genomic DNA templates were extracted from livestock,small mammals and tick specimens in western Yunnan province,and Borrelia DNA was identified through nested PCR amplification of the 5S-23S rRNA intergenic spacer region.Positive samples were further tested with 16S rRNA amplification and verified with the flagellin(FLA)gene.Five genotypes of B.burgdorferi sensu lato were detected in the host animals:B.afzelii,B.garinii,B.burgdorferi s.s.,B.japonica and B.valaisiana.Seven genotypes were found in vector ticks:B.afzelii,B.garinii,B.burgdorferi s.s.,B.ja-ponica,B.valaisiana,B.sinica and Borrelia sp.Moreover,B.afzelii,B.garinii and B.burgerdorferi s.s.were found to be the dominant genotypes,accounting for 85.04%(256/301)of all positive samples.Intraspecific variations were observed in the same genotype of B.burgdorferi from different regions and specimen sources.B.burgdorferi detected in hosts and vec-tors in the same region showed high homology and close phylogenetic relationships.The high genetic diversity of B.burgdor-feri in the hosts and vectors from western Yunnan,and their pathogenicity to humans,indicate potential health hazards to local residents.Prevention and control of Lyme borreliosis must urgently be strengthened in these regions.
western YunnanBorrelia burgdorferihost animaltickdiversity