Bacillus

Bacteria in the genus Bacillus are gram-positive, spore formers, and rod-shaped. They are very diverse in terms of physiology, ecological niche, genes sequences, and regulation. Their impact on human activity varies from probiotic effect1, 2 to severe pathogenecity. The oldest, most infectious, and potentially lethal human disease is the anthrax that is caused by Bacillus anthracis.3 However, many other species within this genus have emerged as new human pathogens associated with foodborne diseases that can cause severe and even fatal infections. These include B. Cereus, B. Weihenstephanenesis, B. Pumilus, B. Mojavensis, B. Licheniformis, B. Subtilis, and B. Circulans. All Bacillus species, due to endospore formation, can survive heat treatment and disinfection procedures and hence pose serious health concerns as contaminants of food or in hospital settings as a cause of nosocomial infections, 4–10 as well as severe illnesses, especially in immunocompromised patients or immunocompetent individuals with risk factors such as intravenous drug use, hemodialysis, and leukemia. The production of toxins and enzymes by these bacteria is considered the causative agent of several human diseases.