Bacillus

Bacillus
Bacillus species are The gram-positive large rods (bacilli) spore-forming( endospores), aerobic: either strictly or facultatively aerobic (that is, they can grow in the presence of oxygen, but do not require it). These bacilli are ubiquitous, and because they form spores they can survive in the environment for many years. and are usually encountered in the medical laboratory as airborne contaminants. Most members of this genus are saprophytic organisms prevalent in soil, water, and air and on vegetation, such as Bacillus cereus and Bacillus subtilis. Some are insect pathogens. B. cereus can grow in foods and produce an enterotoxin or an emetic toxin and cause food poisoning and occasionally eye or other localized infections. Such organisms may produce disease in immunocompromised humans (eg, meningitis, endocarditis, endophthalmitis, conjunctivitis, or acute gastroenteritis). B anthracis, which causes anthrax, is the principal pathogen of the genus. Of the many species of Bacillus, most do not cause disease and are not well characterized in medical microbiology. Several species, however, cause important disease in humans. Anthrax, a prototype disease in the history of microbiology, is caused by Bacillus anthracis. Anthrax remains an important disease of animals and occasionally of humans, and B. anthracis is a major agent of biologic warfare.