Antibiotics Are Antibiotics Used For - 1198 Words

Antibiotics What are antibiotics used for? Antibiotics are used to fight infections which are caused by bacteria. They are not effective against viruses. What are antibiotics? Antibiotics can either be bactericidal or bacteriostatic. Bactericidal antibiotics act to kill bacteria and bacteriostatic act to inhibit and slow down the growth or bacteria. By doing this the antibiotics allow the hosts defence mechanisms to kill the bacteria or fight infection. Where do antibiotics come from? Lead compounds used in the formation of antibiotics are metabolites from microorganisms. These metabolites can be used as antibiotics by themselves or can be further developed to produce new antibiotics. Fungi are also used to inhibit the growth of†¦show more content†¦Penicillin for example acts on peptidoglycan which is only found in prokaryotic cell walls. It is possible for drugs with low therapeutic index to attack or inhibit structures or pathways in the host, this produces the side effects of the drug. How are antibiotics classified? Antibiotics are classified in three main ways: †¢ Their specificity ie. Do they have a broad or narrow spectrum (some antibiotics will act on many different pathogens whereas some will be more specific and only act on certain strains) †¢ The microbial group they attack – antibacterial, antifungal and antiprotozoan †¢ How they stain in the Gram stain procedure What is the gram stain? The Gram stain is a chemical preparation which allows bacteria to be classified into Gram positive and Gram negative by their ability to retain the stain. Bacteria which keep the purple stain are Gram positive and those that loose the stain or turn a pink colour are Gram negative. This procedure is based on the differences in the cell walls structure. The bacterial cell walls will all contain peptidoglycan but the gram positive bacteria the peptidoglycan layer will be thicker. Gram negative, as well as having a thinner peptidoglycan layer, will also have lipopolysaccharides covering the peptidoglycan layer causing less of the stain to be retained. Functions of antibiotics. †¢ Inhibit the synthesis of cell