Comment
Author: Admin | 2025-04-28
Penicillins are a type of antibiotic derived from Penicillium fungi. An antibiotic is a type of medicine that inhibits the growth of, or kills, bacteria.Penicillin G (also called benzylpenicillin) was discovered by accident in 1928. Alexander Fleming, a Scottish physician-scientist was growing a type of bacteria called Staphylococcus aureus on an uncovered petri dish when it became contaminated with mold spores. He observed that the areas of bacteria near the mold were dying. He isolated the substance from the mold that was killing the bacteria and called it penicillin.Another naturally occurring penicillin, penicillin V, was later isolated from the same mold. All other penicillins are semi-synthetic (made by modifying the structure of the original naturally occurring penicillins). Modification extends their spectrum of activity, allows them to be taken orally, and increases their resistance against penicillinase, an enzyme produced by some bacteria that inactivates penicillin.Penicillins work by preventing the cross linking of amino acid chains in the bacterial cell wall. This does not affect pre-existing bacteria, but newly produced bacterial cells have weak cell walls that easily rupture.What are penicillins used for?Penicillins may be used to treat a wide range of infections caused by susceptible bacteria, such as:Dental abscessEar infections (eg, otitis media)GonorrheaPneumoniaRespiratory tract infectionsRheumatic feverScarlet feverSkin infectionsUrinary tract infections.What are the differences between penicillins?The natural penicillins (penicillin G and penicillin V) are only active against gram-positive bacteria (see below for an explanation). Penicillin V is more acid-resistant than penicillin G, which means it can be taken orally.Modern semi-synthetic penicillins include
Add Comment