Microbiology Research Paper

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Melissa Babajko
Microbiology 214BA
Dr. May
June 6, 2012

Staphylococcus aureus- Is a facultative anaerobic, Gram-positive, salt positive, cocci shaped bacterium. Staphylococcus aureus is found as normal part of the skin floral in the nasal passages and on the skin. An estimated twenty percent of people naturally have harmless Staphylococcus aureus on their skin and are long-term carries for Staphylococcus aureus. Staphylococcus aureus is the most common strand of Staphylococcus in humans to date, spread through skin to skin contact or even skin to object contact that an a person infected with Staphylococcus aureus has touched. Staphylococcus aureus is coagulase positive, which induces clumping of the cells and of the blood. Staphylococcus aureus has many immune-evasive strategies that make it the most common strand, such as; it produces leukocidin a toxin that kills white blood cells. It also resists opsonization, survives in phagolysosomes, and is lysozyme resistant. Methicillin-resistant S. aureus, abbreviated MRSA, is one of a number of greatly feared strains of S. aureus, which have become resistant to most antibiotics. MRSA strains are most often found associated with institutions such as hospitals, but are becoming increasingly prevalent in community-acquired infections.

Research Study: IBM, the computer company, working on nanoparticles that polymerize into structures that are able to attack MRSA bacteria without harming the healthy tissue around it. Once these polymers come into contact with water in or on the body, they self assemble into a new polymer structure that is designed to target bacteria membranes based on electrostatic interaction and break through their cell membranes and walls. The physical nature of this action prevents bacteria from developing resistance to these nanoparticles or other antibiotics. The electric charge naturally found in cells is important because the new polymer structures are attracted only to the infected areas while preserving the healthy red blood cells the body needs to transport oxygen throughout the body and combat bacteria. Unlike most antimicrobial materials, these are biodegradable, which enhances their potential application because they are naturally eliminated from the body (rather than remaining behind and accumulating in organs). They are calling this “nanomedicine” and if the trial tests work this could destroy this superbug and eliminate MRSA from hotspots like hospitals. (http://www.forbes.com/sites/amywestervelt/2012/05/16/how-ibm-plans-to-solve-the-mrsa-problem/)

Streptococcus pyogenes- Is a gram- positive, spherical, group a, beta-hemolytic bacterium. Streptococcus pyogenes displays Streptococcus antigen A in its cell wall surface. Streptococcus pyogenes has M-protein on its surface, which are fibrils that are antiphagocytic and are involved in the adherence to the skin and mucos membranes. Streptococcus pyogenes is a catalase negative bacterium that has a capsule that prevents the bacterium from phagocytosis and neutrophils. Another immune-evasive property of Streptococcus pyogenes is the M-proteins on its surface inhibit opsonization. Streptococcus pyogenes is the cause of many human diseases ranging in severity. Disease in a result to infection includes, pharyngitis (sore throat), impetigo and invasive infections such as, cellulitis and erysipelas.

Research Study: Portuguese scientists are looking at new ways to combat the spread of Streptococcus pyogenes by looking into natural antimicrobials. This work aimed to screen the antimicrobial activity of aqueous methanolic extracts of 13 mushroom species. Scientist used a microdilution method to determine the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC). MIC results showed that Russula delica and Fistulina hepatica extracts inhibited the growth of Streptococcus pyogenes. A MBC of 10 mg/ml of Ramaria botrytis extract shoed to have bactericide effects on...
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