Bacterial spores are extremely resilient copies of genetic material bacteria can use to survive harsh conditions. They allow organisms to enter a dormant state when exposed to hostile environments. Once the environmental pressures decline, the spores can activate, allowing the bacteria to start reproducing again. Not all bacteria are capable of forming spores, but some well-known pathogens like anthrax, tetanus, and botulism do, making them a topic of interest and concern for medical researchers.
Organisms can start forming spores in response to specific environmental pressures, like a decline in water supply, rising temperatures, or radiation. It takes several hours to form bacterial spores and whole colonies cannot survive these conditions, but some tough individuals may be able to sporulate in time to protect themselves. The organisms make a copy of their genetic material and trap it inside a tough capsule within the cell membrane. Multiple layers of material surround the spore, increasing the chances of survival.
Radiation, high heat, and extreme dryness do not damage bacterial spores. They also resist treatment with bactericides. This can pose a significant threat to human health and safety in the case of pathogenic organisms, because they can survive most measures used to reduce infection. Swabbing down surfaces with bactericidal soaps, for example, may leave bacterial spores intact. Likewise, irradiation of food products wouldn’t destroy spores.
To kill spores, it is usually necessary to provide prolonged content with a chemical compound that can attack the bacterial cell walls and destroy the genetic material inside. A 10% bleach solution, if left in contact with bacterial spores for at least five minutes, can be an effective decontamination method. Some spores can survive even outside this window, illustrating the hardiness of these structures. Adding spore formation to their life cycle allowed a number of organisms to endure very tough environmental conditions that would have been too harsh for other organisms.
Research on spores examines both how they form, and how they can be addressed if they are created by organisms known to cause disease. This requires carefully controlled environments to trigger spore formation and expose spores to different hazards. These can help research determine what will reliably kill bacterial spores so they can make infection protocol recommendations. Developers of bactericides for environments like hospitals and research facilities also need to stay one step ahead of their targets, as these organisms are highly adaptable and can develop resistance to cleaning solutions over time.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a All The Science researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.