Evaluation of gyrB as chromosomal marker in Bacillus anthracis

Abstract

Bacillus anthracis is generally accepted as the most potent biological warfare agent because of its highly pathogenic nature and transmission efficiency. Identification of chromosomal markers for the rapid detection of B. anthracis is difficult since significant chromosomal homology exists among B. anthracis, B. cereus and B. thuringiensis. In this study, we tested whether the gyrB sequence could be used as the target for the PCR detection of B. anthracis. The gyrB sequence, composed of 1,923 bp, was identical in 17 Korean B. anthracis isolates. The comparison of gyrB sequence between B. anthracis and B. cereus type strain showed 8.8% difference (105 bp among 1,194 bp), and the gyrB sequence similarities of B. cereus, B. thuringiensis and B. mycoides with B. anthracis were 92.3%, 86.9% and 86.1%, respectively. When polymerase chain reaction was designed and performed based on the gyrB sequence, a specific amplicon (351 bp) could be amplified. These results indicate that gyrB could be useful as a chromosomal marker for the rapid screening of B. anthracis by PCR or differentiation of B. anthracis from other related species by multiplex PCR with other plasmid markers.