Bacillus

Spore-forming bacteria
Some bacteria are capable of forming spores around themselves. They are Gram-positive and usually rod-shaped. Bacterial spores are made of a tough outer layer of keratin that is resistant to chemicals, staining and heat. The spore allows the bacterium to remain dormant for years, protecting it from various traumas, including temperature differences, absence of air, water and nutrients. There are two medically-important genera of spore-forming bacteria are: Bacillus, the members of which are aerobic spore formers in the soils, and Clostridium, whose species are anaerobic spore formers of soils, sediments and the intestinal tracts of animals.
Bacillus
It is aerobic, G+ rods arranged in chains, spores are located in center of the cell, non-motile bacilli. Found in soil, water, air and vegetation. Two species are considered medically significant B.anthracis, which causes anthrax and B. cereus, which causes food poisoning similar to that caused by staphylococcus. The other species of bacillus are B.thuringiensis, is important insect pathogen, and is sometime used to control insect. The type species is B.subtilis it is also a notable food spoiler. B. stearothermophilus used to efficiency testing of an autoclave.




Anthrax
Clinical Manifestations
It is zoonotic disease. Anthrax primarily disease of herbivore. Human acquire it as result of contact with infected cattle and sheep. In human the disease takes one of three forms, depending on the route of infection:
1- Cutaneous anthrax
2-Intestinal anthrax
3-Pulmonary anthrax
Bacillus Food Poisoning
The pathogencity of B.anthracis
Diagnosis
Host defenses
The reasons for marked differences in susceptibility to anthrax among different animal species are not known. The protective actions of the live-spore animal vaccine are based on induction of humoral and cell-mediated immunity to protective antigen component of anthrax toxin.
Control
Control in animal is essential for control in human. In anthrax endemic areas, animal that dies suddenly should be handled cautiously and livestock should be vaccinated annually. A human vaccine is available for individuals in high- risk occupation