Phylogenetic typing of Bacillus anthracis isolated in Japan by multiple locus variable-number tandem repeats and the comprehensive single nucleotide polymorphism.

Twelve strains of Bacillus anthracis isolated in Japan were subjected to multiple locus variable-number tandem repeats analysis using 25 marker loci (MLVA25). The results showed that Japanese strains could be divided into two distinct genetic clusters, A3a and A3b. By using newly devised comprehensive single nucleotide polymorphisms (SNPs) analysis, Japanese strains were also divided into two groups. The results obtained by the MLVA25 and plasmids SNP analysis well coincided, indicating that both methods were highly sensitive to discriminate B. anthracis strains. These results suggested that MLVA25 had sufficient discrimination power to identify B. anthracis at the strain level, and that MLVA25 as well as comprehensive SNPs analysis could facilitate further studies of B. anthracis strains including Japanese and other Asian strains.