How Antibiotic Resistance Occurs

Bacteria, which are organisms so small that they are not visible to the naked eye, live all around us--in drinking water, food, soil, plants, animals, and in humans. Most bacteria do not harm us, and some are even useful because they can help us digest food. But A lot of bacteria are capable of causing severe infections.

The ability of antibiotics to stop an infection depends on killing or halting the growth of harmful bacteria. But some bacteria resist the effects of drugs and multiply and spread.

Some bacteria have developed resistance to antibiotics naturally, long before the development of commercial antibiotics. After testing bacteria found in an arctic glacier and estimated to be over 2,000 years old, scientists found several of them to be resistant against some antibiotics, most likely indicating naturally occurring resistance.

If they are not naturally resistant, bacteria can become resistant to drugs in a number of ways. They may develop resistance to certain drugs spontaneously through mutation. Mutations are changes that occur in the genetic material, or DNA, of the bacteria. These changes allow the bacteria to fight or inactivate the antibiotic.

Bacteria can also acquire resistant genes through exchanging genes with other bacteria. "Think of it as bacterial sex," says David White, Ph.D., a microbiologist in the Food and Drug Administration's Center for Veterinary Medicine. "it is a simple form of mating that allows bacteria to transfer genetic material." The bacteria reproduce rapidly, allowing resistant traits to quickly spread to future generations of bacteria. "The bacteria don't care what other bacteria they're giving their genes to," says White. This means that resistance can spread from one species of bacteria to other species, enabling them to develop multiple resistance to different classes of antibiotics

Antibiotics should only be used if needed! Look for alternatives to Antibiotics.