3.7 Analysis of nucleotide and amino acid similarity of SFTSV
strain
The two SFTSV strains isolated from patients and the L, S segment
sequence of SFTSV isolated from ticks in Dandong City, Liaoning Province
and Yanji City, Jilin Province were 100% identical, while the M segment
sequence similarity was 99%, which shows that the main source of
transmission of SFTS in patients in the Liaoning Province are the ticks
distributed in local or nearby areas.
Comparison of the four SFTSV strains with each genotype sequence
revealed that it was the closest in nucleotide sequence and
corresponding amino acid sequence to genotype A SFTSV (Table 2). The
sequence similarities of the isolated L, M, and S nucleotides (and
deduced amino acids) with other genetic A-type strains are between
95.95‒100 (98.90‒100), 97.12‒100 (98.32‒100), 95.08‒100 (99.59‒100)%,
respectively (Table 3‒5). The nucleotide sequence similarity is above
95%, and the corresponding amino acid similarity is above 98%, which
further suggest that the four SFTSV strains are genotype-A strains.