Occurrence and genetic diversity of Bacillus anthracis strains isolated in an active wool-cleaning factory

Culturable microorganisms from various samples taken at an active factory performing wool and goat hair cleaning were isolated and analyzed. Bacillus anthracis was found in air filter dust, wastewater, and goat hairs, where it accounted for approximately 1% of the total counts of viable bacteria. Consistent with the countries of origin of the processed material (South Caucasian and Middle Eastern), all B. anthracis isolates belonged to the same phylogenetic cluster, as determined by variable-number tandem repeat (VNTR) typing at eight loci. Within this cluster, five closely related VNTR subtypes could be identified, of which two were previously unreported. Additional diversity was observed when more sensitive genetic markers were assayed, demonstrating the multifocal nature of goat hair contamination. Goat hair originating from areas where anthrax is endemic remains a material with high biological risk for modern woolworkers.