Molecular characterization of Bacillus anthracis isolates recovered from nomic and nonnomic hosts

Anthrax, which is primarily a disease of herbivores, is known to infect many animal species. In order to break the cycle of anthrax infection, it is important to identify the potential hosts or reservoirs of its causative agent. Therefore, this study aimed to characterize Bacillus anthracis isolates recovered from a variety of hosts and environments during anthrax sporadic in the Kars and Kayseri regions of Turkey. For this purpose, a total of 23 B. anthracis field isolates obtained from human, cattle, sheep, dog, horse, puma, soil, and fodder were used. In addition, the Sterne vaccine strain was included. All B. anthracis isolates were confirmed via molecular tests using plasmid-based PCR and 16S rRNA gene sequencing. All were found to be positive for protective antigen (PA) and capsule (Cap) genes. The presence of two specific 16S rRNA positions (1139 and 1148) with nucleotide mismatches was used to differentiate between B. anthracis species in the Bacillus cereus group, which has a relatively high (>99%) 16S rRNA sequence similarity. All of our isolates, including the Sterne vaccine strain, were classified in the same 16S rRNA type (Type 6) that has been reported previously as being the predominant type for B. anthracis isolates.