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Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Plants and Fungi Used to Treat Infectious Disease,Infectious Disease,World wide,infectious disease is the number one cause of death accounting for approximately one-half of all deaths in tropical countries,Infectious disease mortality rates are actually increasing in developed countries,such as US,Death from infectious disease,ranked 5th in 1981,has become the 3rd leading cause of death in 1992,Infectious disease underlying cause of death in 8%of deaths occurring in US,Terms,Antimicrobial,=a substance,which destroys or inhibits the growth of microorganisms,Antiseptic,=a substance that checks the growth or action of microorganisms especially in or on living tissue,Antibiotic,=a substance produced by or derived from a microorganism and able to inhibit or kill another microorganism,Antibiotics vs Antimicrobials,Antibiotics are toxic to microorganisms,Produced by fungi and/or bacteria,In the natural environment,antibiotics give the producing organism advantages over competing microorganisms for available nutrients and space,First antibiotic put into large-scale production was penicillin,Overview,Antibiotics from fungi,Antimalarials from plants,Other antimicrobials from plants,Penicillin,By-product of certain,Penicillium,species,Inhibits the growth of gram-positive bacteria,Blocks wall synthesis in bacteria and results in death of the bacterial cell by lysis,Surpassed known therapeutic agents by suppressing bacterial growth without being toxic,Discovery of Penicillin,Infusions of moldy bread,cheese,meat,and soybeans have long history as folk treatment for wounds,19th Century observations of antibiosis by,Penicillium,spp,Roberts-1874,Tyndall-1881,others,Sir Alexander Fleming,Flemings Petri Dish,Research at Oxford University,In 1939,Howard Florey and Ernst Chain began investigating naturally occurring antibacterial compounds and came across Flemings report on penicillin,Within a year,the team at Oxford had chemically analyzed the compound and demonstrated that it could destroy certain types of bacteria in test tubes,Progress Continues,War in Europe was escalating and Florey and Chain realized the potential for treating war wounds,Tests on infected animals were successful,1941 the first human tests were conducted,Research was moved to various sites in the United States because of the war,Really miraculous cures were reported in human tests,and mass production was finally achieved,Summer of 1943,Cantaloupe was found contaminated with,Penicillium chrysogenum,.,The fungus produced 200 times more penicillin than Flemings isolate.,This species was used in the industrial production of the drug and continues to be used today,Mass Production Achieved,By D-Day in 1944,there was enough penicillin to treat all British and American casualties of the European invasion,By the time World War II ended,sufficient penicillin was available for civilian use,In 1945 Florey,Chain,and Fleming received the Nobel Prize for their work in developing the first miracle drug,Start of Synthetics,Soon after World War II,the pharmaceutical industry developed chemically altered versions of the penicillin molecule,Modified penicillins provided for greater stability,broader anti-bacterial activity,and also oral administration which would permit home use of antibiotics,Penicillin Today,Still the most widely used antibiotic,Still the drug of choice to treat many bacterial infections,Scientists have continued to improve the yield of the drug,Present day strains of,P.chrysogenum,are biochemical mutants that produce 10,000 times more penicillin than Flemings original isolate,Drawbacks-1:Resistance,Over-prescribing by physicians and veterinarians commonly occurs,Antibiotics were incorporated into animal feed for use in feedlots,Widespread use led to the evolution of,penicillin-resistant,bacteria,Drawback-2:Allergies,Small percentage of population is allergic,Can result in severe or even fatal anaphylactic reactions,Penicillin is the most frequent cause of anaphylaxis,Several hundred die each year from anaphylaxis due to penicillin allergy,Synthesis of Penicillin,Penicillin-one of a family of,b,-Lactam antibiotics,b,-Lactams produced by asexual fungi,some ascomycetes,and several actinomycete bacteria,b,-Lactams are synthesized from amino acids valine and cysteine,b,Lactam Basic Structure,Penicillin-G,Penicillin-G,Still an important antibiotic,Disadvantage has been that it is unstable in acid conditions,Given by injections-otherwise stomach acids would destroy,Penicillin-V,phenoxy methyl penicillin,Semi-Synthetic Penicillins,A strain of,Penicillium,chrysogenum,found that produced large amounts of 6-amino penicillanic acid(6-APA),6-APA lacked antibiotic activity but it could be used to add a variety of side chains and create semi-synthetic penicillins,methicillin and ampicillin,Semi-synthetics have made penicillins a versatile group of antibio
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