S. Aureus Crystal Structure

Aspirin was synthesized by reacting salicylic acid with acetic anhydride in the presence of phosphoric acid, H3PO4, as a catalyst:

As detailed in Pavia 's Organic Laboratory techniques the reaction is expected to proceed via the following reaction:

     “In the Rhabdomyosarcoma (268210) cell line TE125.5, Schwienbacher et.al (1988) found a G-to-A transition at nucleotide 688 that introduced an arginine in place of a cysteine in the product of the BWR1A gene. The change was present in a homozygous state, suggesting that loss of the normal allele occurred during the tumorigenic conversion.” (John Hopkins University, 1998.) A number sign (#) is used with this entry because of evidence that Rhabdomyosarcoma, which maps to 11p15.5, is caused by mutation in the Beckwith-Wiedemann region 1A gene.

Antibiotics are inarguably one of the greatest advances in medical science of the past century. Although the first natural antibiotic Penicillin was not discovered until 1928 by Scottish biologist Alexander Flemming, evidence exists that certain plant and mold growths were used to treat infections in ancient Egypt, ancient India, and classical Greece (Forrest, 1982). In our modern world with the advent of synthetic chemistry synthetic antibiotics like Erithromycin and its derivative Azithromycin have been developed. Antibiotics have many uses including the treatment of bacterial and protozoan infection, in surgical operations and prophylactically to prevent the development of an infection. Through these applications, antibiotics have saved countless lives across the world and radically altered the field of medicine. Though a wonderful and potentially lifesaving tool, antibiotic use is not without its disadvantages. Mankind has perhaps been too lax in regulation and too liberal in application of antibiotics and growing antibiotic resistance is the price we must now pay. A recent study showed that perhaps 70% of bacterial infections acquired during hospital visits in the United States are resistant to at least one class of antibiotic (Leeb, 2004). Bacteria are not helpless and their genetic capabilities have allowed them to take advantage of society’s overuse of antibiotics, allowing them to develop

Staphylococcus aureus (S. aureus) is a spherical bacteria which is known to produce a cytotoxin called Panton-Valentine leucocidin (PLV) which destroys leukocytes, and kills tissue (Lina et al., 1999). Five percent of strains of Staphylococcus are known to produce the disease-causing toxin (Lina et al., 1999), but though the amount of PLV-producing strains is somewhat small, the strains which produce PLV are apparently resistant to vancomycin, an antibiotic commonly used to treat staph infections (CDC, 2002). The first recorded case of S. aureus resistance to vancomycin was a reduction in sensitivity to the antibiotic observed in Japan, and has since spread to the United States (CDC, 2002). The most common source of infection of these drug-resistant bacteria are actually in hospitals, wherein the patients are exposed to the bacteria and subsequently infected (CDC, 2002).

Antibiotic resistance is when microorganisms, such as bacteria, are able to survive an exposure to antibiotics and these bacteria are now resistant to the effects of these antibiotics. Antibiotic resistance in bacteria has been an issue since antibiotics were discovered. The fact that bacteria can become resistant to our medical treatments such as antibiotics is a natural evolutionary process, but there are certain human contributions that definitely speed up the process. For example, one of the main contributions that will be discussed is the problem of over prescription of the antibiotic drugs. The

mutation is phenylalanine 508 known as delta F508. Delta F508 is a deletion of 3 nucleotides

Question 2: (29 pts) In the article, “Effect of an Ala81His Mutation on the Met80 Loop Dynamics of Iso-1-cytochrome c,” figure 1 includes a portion of the protein sequence.

(APP). APP is cleaved by two different enzymes to produce one amyloid beta monomer, which aggregates with other monomers to form cytotoxic

Class 1: The mutation occurring in around 10% of patients interferes with the protein synthesis, there is a premature stop codon so translation of mRNA ends early resulting in no protein present in the cell membrane. (Pettit, 2013)

Staphylococcus aureus is a leading cause of human bacterial infections worldwide1, and following the discovery and widespread utilization of antibiotics, S. aureus has evolved to become resistant to a number of antimicrobial treatments. Most notably, Methicillin-resistant Staphylococcus aureus (MRSA) strains have acquired the mecA gene, encoding the penicillin binding protein (PBP2a), which confers resistance to oxacillin and all β-lactam antibiotics 2. These characteristics, combined with other virulence factors, have made MRSA infections difficult to treat, and lead to MRSA being recognized as a significant cause of morbidity and mortality 3. MRSA is also the leading cause of nosocomial infections4–6, contributing significantly to increased healthcare costs 7. CDC estimated in 2008 that MRSA was responsible for 89,785 cases of disease, causing 15,249 deaths in the US8.

Staphylococcus Aureus is a gram-positive bacterium that is most commonly responsible for causing staph infections.

These mutations, no matter what process that has led to their occurrence, block the action of antibiotics by interfering with their mechanism of action (1). Currently, antibiotics attack bacteria through one of two mechanisms. In both mechanisms the antibiotic enters the microbe and interferes with production of the components needed to form new bacterial cells. Some antibiotics act on the cell membrane, causing increased permeability and leakage of cell contents. Other antibiotics interfere with protein synthesis in cells. They block one or more of the steps involved in the transformation of nucleic acids into proteins.

Have you ever had a small pimple that was a nuisance and you decided to rid by squeezing? Or a nick in the skin from shaving? Then after a couple of days you noticed it ends up red, warm, inflamed, swollen and very painful. More than likely you have opened a nesting ground for the most common bacteria found on the human body, Staphylococcus Aureus.

active once the immune system becomes weakened where the once quiescent bacterium has multiplied and has developed in the lungs and has begun destroying lung tissue (Encarta, 2005). Although bacterium may not be antibiotic resistant at first, it can become resistant by mutating and changing its genetic structure and in turn, reproducing rapidly (Davies, 1999). When this happens, it signifies that one’s body has become antibiotic resistant, in which particular drugs no longer function properly and no longer does its job correctly.