Other Bacillus Species
Bacillus spores are widespread in the environment, and isolation of one of the more than20 Bacillus species other than B. anthracis from clinical material usually represents conta-mination of the specimen. Occasionally B. cereus, B. subtilis, and some other species pro-duce genuine infections, including infections of the eye, soft tissues, and lung. Infection is usually associated with immunosuppression, trauma, an indwelling catheter, or contamina-tion of complex equipment such as an artificial kidney. The relative resistance of Bacillus spores to disinfectants aids their survival in medical devices that cannot be heat sterilized.
B. cereus deserves special mention. This species is most likely to cause opportunisticinfection, which suggests a virulence intermediate between that of B. anthracis and the other species. A strain isolated from an abscess has been shown to produce a destructive pyogenic toxin. B. cereus can also cause food poisoning by means of enterotoxins. One enterotoxin acts by stimulating adenyl cyclase production and fluid excretion in the same manner as toxigenic E. coli and Vibrio cholerae.