Antibiotics Biology Presentation

Antibiotics About Antibiotics About Antibiotic Resistance Something we should know when we take antibiotics

About Antibiotics: What is antibiotics? Chemical Compounds Able to kill or inhibit the growth of bacteria (e.g. human) without causing significant damage to the host Naturally produced (e.g. penicillin) by mold or bacterium, or Synthetically made (e.g. fluoroquinolones)

About Antibiotics: Discovery of antibiotics In 1929, first discovered by British Scientist Alexander Fleming. However, he could not purify the compound due to its instability. Until the period of World War II (1939-1945), two other British scientists, Florey and Chain successfully managed to produce antibiotics in industrial scale for widespread use.

About Antibiotics: How do antibiotics work? Bacteriostatic antibiotics (e.g. Penicillin) Not actually kill the bacteria Stop the cells from growing and multiplying Allows time for the infected host to mount an immune response  Eliminate the non-growing infectious agent (i.e. the bacteria)

About Antibiotics: How do antibiotics work? Bacteriocidal antibiotics Actually kill the bacteria Preferred choice when the patient’s immune system is weakened or incapable of destroying the organisms itself

About Antibiotics: How do antibiotics work? In both cases, bacteriostatic and bacteriocidal antibiotics disrupt the bacterial cells by attacking: the outer cell wall or inner membrane, or the chemical pathways necessary for the bacteria to live or reproduce. NO activities against most of the viruses.

About Antibiotics: How do antibiotics work? E.g. Penicillin Prevents the cross-linking of small peptide chains in the main cell wall polymer of bacteria. Pre-existing cells are not affected. All newly produced cells grow abnormally Unable to maintain cell wall rigidity

About Antibiotics: How are antibiotics used? In medical ways:  to treat illness caused by bacteria to prevent bacterial infections in surgery In the supply of food: to increase the growth of certain food animals used as pesticides to control bacterial infections in food crops.

About Antibiotics Resistance: What is antibiotic resistance? An antibiotic lost its ability to effectively control or kill bacterial growth. i.e. bacteria are “resistant” and continue to multiply in the presence of therapeutic levels of and antibiotics

About Antibiotics Resistance: Why do bacteria become resistant to antibiotics? Natural phenomenon 4. Eventually there are more antibiotic-resistant bacteria than non-resistant. 2. The bacteria with resistance survive after the antibiotics are gone. 3. ....and reproduce, inherit the resistant genes to their offspring. 1. Antibiotics attack and kill off bacteria without resistance.

About Antibiotics Resistance: Why do bacteria become resistant to antibiotics? Resulting in the survival of resistant strains of bacteria. survival for the fittest  “Natural Selection” Low-level of natural selection  produced by bacteria to against each other (w/out human action) High-level of natural selection  by overuse of antibiotics (human action)

About Antibiotics Resistance: How do bacteria become resistant? By genetic mutation Chance: 1 / 1,000,000 – 10,000,000  produce enzyme to inactivate the antibiotics  eliminate cell target that the antibiotic attacks

About Antibiotics Resistance: How do bacteria become resistant? By acquiring resistance from another bacterium  by conjugation Bacteria have the ability to “collect” multiple resistant traits over time  resist to many different families of antibiotics

About Antibiotics Resistance: How does antibiotic resistance spread? “Vertically”  new generations inherit antibiotic resistance genes. “Horizontally”  share or exchange genes with other bacteria , even occur between different species.

About Antibiotics Resistance: How does antibiotic resistance spread? Environmentally Via airplane, water and wind, coughing, or contact of unwashed hands.

About Antibiotics Resistance: Can bacteria lose their antibiotic resistance? YES Slow process Stop using antibiotics for a while  the population of bacteria that responds to antibiotics increases

Something we should know when we take antibiotics Antibiotics may cause side effects (e.g. nausea, diarrhea and stomach pain) In some people, an allergic reaction (characterized by rash and itching; or in severe cases, difficulty breathing) can occur Should only be used when prescribed by your doctor

Something we should know when we take antibiotics must be taken for the full amount of time prescribed by your doctor should not be saved and reused

Please Take Care (o^_^o) Presented by 6B Law Wei Bong

Reference URL AUPA: Alliance for the Prudent Use of Antibiotics http://www.healthsci.tufts.edu/apua/apua.html Medem Inc. http://www.medem.com/medlb/article_detaillb.cfm?article_ID=ZZZPT86928C&sub_cat=277 Medline plus http://www.nlm.nih.gov/medlineplus/antibiotics.html The Microbial World http://helios.bto.ed.ac.uk/bto/microbes/penicill.htm Stalking the Mysterious Microbe www.microbe.org/microbes/ mutations.asp