Topics: Bacteria, Penicillin, Immune system Pages: 2 (302 words) Published: March 28, 2013

Penicillin is a group of antibiotics derived from Penicillium fungi. Penicillin antibiotics were the first drugs that were effective against many previously serious diseases. They are used in the treatment or prevention of many different bacterial infections, usually caused by Gram-positive organisms. Some of the penicillin types include ampicillin, amoxicillin, flucloxacillin, and phenoxymethylpenicillin.

Penicillin was discovered by Ernest Duchesne, a medical student, in the late 19th century and then rediscovered for its antibiotic properties by Alexander Fleming in 1928. He realized this antibiotic property when a sample of certain bacteria became contaminated by some mold and that all the bacteria cells closest to the mold were dying.

Our immune systems can destroy many harmful bacteria, as we have white blood cells that attack them before they multiply. There are instances when a bacterial infection is too much for our bodies and this is when we use antibiotics. Bacteria constantly build up their cell walls. Penicillin works by damaging and penetrating those cell walls. Though bacteria can build a resistance to this by making beta-lactamase, this can be counteracted by combining penicillin with beta-lacamase inhibitors.

Many kinds of bacteria are now penicillin resistant.


Erythromycin is in a group of drugs called macrolide antibiotics. Macrolide antibiotics slow the growth of, or sometimes kill, sensitive bacteria by reducing the production of important proteins needed by the bacteria to survive. Erythromycin is used to treat many different types of infections caused by bacteria. Abelardo Aguilar, a Filipino scientist, first discovered it. He sent some soil samples to his employer and they managed to isolate erythromycin from the metabolic products of a strain of Streptomyces erythreus.

Most of erythromycin is metabolized by demethylation in the liver. Its main elimination route is in the bile. Its...
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