GENETIC CHARACTERIZATION AND PHYLOGENETIC ANALYSIS OF BACILLUS ANTHRACIS STERNE STRAIN BY 16S RRNA GENE SEQUENCING

Abstract

Anthrax, caused by Bacillus anthracis, is a fatal disease and all the warm blooded
animals are susceptible to this disease. Many livestock populated areas in Pakistan are endemic for
Anthrax (Thappa and Karthikeyan 2001), therefore the livestock population is annually vaccinated
against Anthrax. Veterinary Research Institute (VRI) has been producing Anthrax Spore Vaccine
(ASV) for a couple of decades. The current study was designed for molecular characterization of the
microorganism used for vaccine production (Bacillus anthracis Sterne strain) and its phylogenetic
relationship with related strains and Bacillus species. For this purpose, 16S rRNA gene was amplified
and sequenced and was found 100% genetically similar to the reference sequence with respect to 16S
rRNA gene. Phylogenetic analysis revealed that sequenced strain showed a close phylogenecity with
Bacillus anthracis strain 1144 and Bacillus anthracis strain V77-NP-1R. Moreover, the organism was
found genetically closer to Bacillus cereus than to Bacillus mycoides and Bacillus thuringiensis with
respect to 16S rRNA gene sequence.