Molecular characterization of a defensin gene from a hard tick, Dermacentor silvarum.

ABSTRACT: BACKGROUND: Ticks are distributed worldwide and considered as vectors of many human diseases. Tick defensins, a family of antimicrobial peptides, form the first line of defense against pathogens. FINDINGS: A defensin-like gene, named Ds-defensin, was identified from a cDNA library of the hard tick Dermacentor silvarum collected from northeast China. The full-length cDNA of Ds-defensin was 225 bp, encoding a 74 amino acid peptide. The nucleotide sequence of Ds-defensin shared 98.2% similarity to putative defensin from Dermacentor marginatus. RT-PCR results suggested that Ds-defensin was extensively expressed in tick salivary gland and midgut, with a higher expression level in midgut. Ds-defensin showed broad antimicrobial activity against various Gram-positive and Gram-negative bacteria, as well as the fungus Candida albicans. CONCLUSIONS: We characterized a functional defensin from D. silvarum of China. Ds-defensin showed bactericidal activity against various Gram-positive and Gram-negative bacteria. Ds-defensin can be expected to be introduced to the medical field as a new molecule with antibacterial activity.

SUBMITTER: Wang J 

PROVIDER: S-EPMC4311433 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature