Staphylococcus aureus-The evolution of bacterial resistance

Running head : STAPHYLOCOCCUS AUREUS AND THE EVOLUTION OF RESISTANCE

The Evolution of Bacterial Resistance in Staphylococcus aureus : History Mechanisms , and Remedial Strategies

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Abstract

The discovery of penicillin by Fleming in 1929 was a breakthrough that seemed to ensure recovery from bacterial infections , in particular S aureus infections . Unfortunately , resistance was observed almost immediately after the wonder drug ' was released for public use . Ever since , the battle between man and bacteria has continued . However , in the last decade , an increasing numbers of S . aureus strains have

br appeared , especially the Methicillin Resistant Staphylococcus aureus (MRSA ) and Vancomycin Resistant Staphylococcus aureus (VRSA . These strains were not common at one time and were basically found in a few hospitals . Nowadays , their spread is endemic . Not only hospitals have them but closed community institutions with elderly people and people with disabilities . Individuals with compromised immune systems are most at risk since they cannot defend themselves against the bacteria Bacteria like S . aureus have established different levels of resistance which are mostly based on genetic recombination and the acquisition of Resistance Transformation Factors (RTFs ) onto their plasmids Acquisition can come from other strains of S . aureus or other species of bacteria . It should be very clear that bacterial resistance is a threatening problem that has been caused by the overuse as well as the misuse of antibiotics like penicillin . In addition , antimicrobial products work the same way than antibiotics do , thereby creating a much larger environmnent for mutants to appear , especially when they are overused . Many research laboratories are now designing novel drugs that they hope will replace the failing antibiotics . The main strategy is to target specific components of the resistance pathways and engineer molecules that will interfere with these pathways at different levels

The Evolution of Bacterial Resistance in Staphylococcus aureus : History Mechanisms , and Remedial Strategies

In the United States alone , 500 ,000 patients get a staphylococcal infection every year . Staphylococcus aureus is found on the skin or in the nose of a healthy person . S . aureus infections vary in their gravity . They can go from minor skin infections such as pimples , boils and cellulitis , even causing abscesses . Severe infections threaten lives : pneumonia , meningitis , endocarditis , Toxic Shock Syndrome , and Septicemia are a few examples of such infections . S . aureus belongs to the Gram-positive bacterial group . Gram-positive indicates that when stained with Gram 's stain , the characteristic color of the cells taking up the dye will be violet blue (Gram-negative gives a red color . It is called a coccus because it is spherical in shape . In fact , it looks like grape-like clusters when viewed under a microscope . When the cells are grown on blood agar , large golden yellow colonies are observed hence the name aureus ' from the Latin word for gold . The genome for the bacterium possesses approximately 2 ,600 genes , representing 2 .8 million bp of DNA . Plasmids may also be counted as part of its genome The basic ways an infection can spread is through skin contacts with an...