A spore is a reproductive cell produced by certain fungi, plants (moss, ferns), and some bacteria.
Certain bacteria make spores as a defensive mechanism. Bacterial spores have thick walls and are very resistant to high temperatures, humidity, and other unfavorable conditions. The bacteria Clostridia form spores that cause gas gangrene and antibiotic-associated colitis.
Chemical disinfection kills bacteria, but does not destroy their spores. Sterilization destroys spores as well as bacteria, and requires high temperatures and high pressures. In health-care settings, sterilization is usually accomplished using a device called an autoclave.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.