Bacillus cereus

Structure and Physiology

Bacillus cereus is a Gram-positive, rod-shaped, endopore-forming facultative aerobe bacterium related to Bacillus anthracis and Bacillus thuringiensis.

Transmission and Disease

Although B. cereus is commonly associated with food-borne illnesses, this microbe can also be responsible for several local and systemic infections.

Disinfection

Due to this bacterium's ability to sporulate, B. cereus is often relatively challenging to disinfect.

Bacillus subtilis

Structure and Physiology

Bacillus subtilis is a spore forming, motile, rod-shaped, Gram-positive, facultative aerobe. It is mostly found in soil and vegetation with an optimal growth temperature from 25-35 degrees Celsius. B. subtilis has the ability to produce and secrete antibiotics. The genomic structure of this microorganism contains five signal peptidase genes that are important for the secretion of these antibiotics. B.subtilis has shown to be capable of secreting polymyxin, difficidin, subtilin, and mycobacillin.

Clostridium difficile

Structure and Physiology

This bacteria is a Gram-positive, rod shaped, endospore generating obligate anaerobe. Clostridium species are part of the normal human gut flora that produce spores which are highly resistant to chemical and environmental conditions.

Transmission and Disease

C. difficile is commonly associated with hospital acquired infections and is known to cause antibiotic assisted colitis.