A substance that kills microorganisms such as bacteria or mold, or stops them from growing and causing disease.

A substance that kills or slows the growth of bacteria.

Substances naturally produced by microorganisms or their derivatives that selectively target microorganisms not humans. Antibiotics kill or inhibit the growth of microorganisms by targeting components of the microbial cell absent from human cells, including bacterial cell walls, cell membrane, and 30S or 50S ribosomal subunits. These substances are used in the treatment of bacterial and other microbial infections.

Substances that kill or inhibit the growth or other functions of microorganisms. These substances are used in the treatment of bacterial and other microbial infections, though this term is most often used to describe antibacterial agents.

Substances produced by microorganisms that can inhibit or suppress the growth of other microorganisms.

Antibiotics are medicines that fight bacterial infections in people and animals. They work by killing the bacteria or by making it hard for the bacteria to grow and multiply. Antibiotics can be taken in different ways: Orally (by mouth). This could be pills, capsules, or liquids.; Topically. This might be a cream, spray, or ointment that you put on your skin. It could also be eye ointment, eye drops, or ear drops.; Through an injection or intravenously (IV). This is usually for more serious infections. Antibiotics only treat certain bacterial infections, such as strep throat, urinary tract infections, and E. coli. You may not need to take antibiotics for some bacterial infections. For example, you might not need them for many sinus infections or some ear infections. Taking antibiotics when they're not needed won't help you, and they can have side effects. Your health care provider can decide the best treatment for you when you're sick. Don't ask your provider to prescribe an antibiotic for you. Antibiotics do not work on viral infections. For example, you shouldn't take antibiotics for: Colds and runny noses, even if the mucus is thick, yellow, or green; Most sore throats (except strep throat); Flu; Most cases of bronchitis. The side effects of antibiotics range from minor to very severe. Some of the common side effects include: Rash; Nausea; Diarrhea; Yeast infections. More serious side effects can include: C. diff infections, which cause diarrhea that can lead to severe colon damage and sometimes even death; Severe and life-threatening allergic reactions; Antibiotic resistance infections
. Call your health care provider if you develop any side effects while taking your antibiotic. You should only take antibiotics when they are needed because they can cause side effects and can contribute to Antibiotic resistance infections. Antibiotic resistance happens when the bacteria change and become able to resist the effects of an antibiotic. This means that the bacteria continue to grow. When you take antibiotics, it is important that you take them responsibly: Always follow the directions carefully. Finish your medicine even if you feel better. If you stop taking them too soon, some bacteria may survive and re-infect you.; Don't save your antibiotics for later.; Don't share your antibiotic with others.; Don't take antibiotics prescribed for someone else. This may delay the best treatment for you, make you even sicker, or cause side effects. Centers for Disease Control and Prevention

Antibiotics are drugs used to treat bacterial infections. They are ineffective against viral infections and most other infections. Antibiotics either kill microorganisms or stop them from reproducing, allowing the body's natural defenses to eliminate them.

Antibiotic, chemical substance produced by a living organism, generally a microorganism, that is detrimental to other microorganisms. Antibiotics commonly are produced by soil microorganisms and probably represent a means by which organisms in a complex environment, such as soil, control the growth...