Penicillins are a subclass of antibiotics used to treat illnesses like streptococcal infections and meningococcal infections. Cephalosporins can treat a wide variety of conditions, including bacterial pneumonia and some skin infections. Antibiotics are medicines used to treat or prevent bacterial infections - they do not work against viral infections such as colds or the flu. They are usually prescribed for serious bacterial infections or if the immune system is weakened, though many infections can improve without them. Antibiotics vary in their range of action. Some are highly specific. Others, such as the tetracyclines, act against a broad spectrum of different bacteria. These are particularly useful in combating mixed infections and in treating infections when there is no time to conduct sensitivity tests. Bactericidals kill bacteria directly, whereas bacteriostatics prevent them from dividing. However, these classifications are based on laboratory behavior. The development of antibiotics has had a profound effect on the health of people for many years. Also, both people and animals have used antibiotics to treat infections and diseases. Antibiotics can be natural (produced by fungi or bacteria to outcompete rivals), semi-synthetic (modified from natural compounds), or synthetic (designed entirely in the lab). Their purpose? To either kill bacteria outright (bactericidal) or stop them from reproducing (bacteriostatic). Antibiotics specifically treat infections caused by bacteria, such as Staph., Strep., or E. coli., and either kill the bacteria (bactericidal) or keep it from reproducing and growing (bacteriostatic). And remember, antibiotics do not work against viral infections, like a cold, most coughs or COVID. When should I use an antibiotic? Antibiotics are medicines that help stop infections caused by bacteria. They do this by killing the bacteria or by keeping them from copying themselves or reproducing. The word antibiotic means. 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. Antibiotics are powerful, lifesaving medications that treat bacterial infections like strep throat and urinary tract infections. But they’re not for every sickness, and they can cause side effects like diarrhea. Learning when you need antibiotics and how to take them properly can help you benefit from these medications with the least risk. An antibiotic is a type of antimicrobial substance which is active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. [1][2] They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal.