D6+Antibacterial

ANTIBACTERIALS  //Include the discovery by Fleming and the development by Florey and Chain.// ||   ||  //Penicillins work by interfering with the chemicals that bacteria need to form normal cell walls. Modifying the side-chain results in penicillins that are more resistant to the penicillinase enzyme.// ||   ||  //The use of penicillins in animal feedstock also contributes to the resistance problem.// ||   ||
 * D. 6 Antibacterials ||
 * D. 6. 1 Outline the historical development of penicillins.
 * D. 6. 2 Explain how penicillins work and discuss the effects of modifying the side-chain.
 * D. 6. 3 Discuss and explain the importance of patient compliance and the effect of penicillin overprescription.

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1941: Florey and Chain used penicillin to treat a policeman dying from septicaemia (blood poisoning). They recorded dramatic improvements in his conditions, however supplies ran out before policeman was cured, he relapsed and died. ======

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Penicillin works by interfering with the enzyme that bacteria need to make normal cell walls. As the bacterium cell swells, the osmotic pressure causes the weakened cell wall to disintegrate, and the bacterium dies. ======

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Penicillin became readily available to doctors, and it was given to treat minor illnesses. Over time some bacteria developed resistance to penicillin, due to the presence of enzyme penicillinase (which can deactivate penicillin G). ======

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Chemists have developed other penicillins (where the active part of the molecule is retained, but the side chain is changed) to combat this problem. However, bacteria multiply and mutate very fast, and so new antibiotics must be developed (a fight), to be effective against even more resistant “super-bugs”. ======


 * ====== //Staphylococcus aureus// (MRSA) – methicillin resistant (it can make beta-lactamase, which degrades penicillin)  ======
 * ====== Strains of //Mycobacterium tuberculosis//, which causes TB.  ======


 * ====== Strict adherence to a recommended treatment regime is necessary for the effectiveness  ======
 * ====== Treatment involves a “cocktail” of several antibiotics => prevent the risk of further resistance developing.  ======