Penicillin antibiotic works by changing the formation of a bacterial cell during its growth. This process weakens and eventually kills the bacteria. It is derived from a common mold. Penicillin treatment is used to treat multiple types of bacterial infections. It was detected when Sir Alexander Fleming discovered that bacteria colonies could be destroyed by a mold of penicillin notatum. 20 years later, two scientists Ernst Chain and Howard Florey isolated penicillin and developed the powdery medicine. This discovery later lead to other medications that could kill types of disease causing bacteria in the body.

Penicillium is a fungi with multiple strains. Some strains are used to start the production of some cheese. Penicillin can be naturally occurring or it can be cultured to produce medication. Cultures are submerged because this particular strain requires lots of moisture and air. When they are cultured, the liquid it is submerged in consists of liquor, glucose, salts, nutrients, and lactose. It is constantly agitated and eventually the mold grows and when fermentation is complete, the medicine is ready for consumption. Penicillin injections, suspension and tablets are available for treatment of bacterial infections. It cannot prevent infection though it is used to treat existent bacterial infections. It is approved for use in adults and children. It is possible to be allergic to penicillin, so other antibiotics should be prescribed. Injections are sometimes referred to as penicillin vaccines. It is important to know that there is no such drug. Vaccines are meant to prevent illness. Penicillin does not prevent, it fights and cures bacterial infections.

Penicillin is usually prescribed for use by mouth two or three times a day for up to 10 days. While oral antibiotics are prescribed for the most common bacterial infections like a sinus infection or ear infection, an injection is available to treat more serious conditions like strep throat. Administering the medication directly into the blood stream gives the body a head start on fighting the infection. Larger doses are used in the injection than the ones taken orally. It gives the body the extra boost it needs to begin the fight. These injections can also be used as penicillin treatment in patients diagnosed with rat-bite fever. This condition is caused by bacteria that is passed from rodent to human through urine or mucous secretions.

Three steps are required for the biosynthesis of penicillin. The first is the condensation of three different amino acids, L-a-aminoadipic acid, L-cysteine, and L-valine into a tripeptide. The second step is for the enzyme to change and form a ring which exchanges chains in the third step and becomes the antibiotic. Penicillin works by inactivating the enzyme needed for cross linking cell walls in bacteria. By preventing the bacteria cell from forming its walls, the cell wall is critical for bacteria to maintain its integrity so without this ability it dies. Penicillin vaccines are not available. Penicillin antibiotic has no effect on viral infections, it can only work on bacterial infections.