Microbiology Essay

Esherichia coli also known as E. coli is a bacterium that lives in your gut. (1). it was founded by Theodore von Esherich in 1888. There are many people that can get the bacteria. Also there are thousands of strands of E.coli. Six E. coli O157 outbreaks were identified during 2007. Four of the outbreaks involved foodborne transmission. (Eshericha Coli). Six Minnesota cases and one Wisconsin case with the same or closely-related PFGE subtype of E. coli O157:H7, and an additional Minnesota case of Shiga-toxin producing E. coli that was not culture-confirmed, attended the Minnesota State Fair in August. All but one of the cases showed cattle or visited the cattle

Humans are a natural reservoir for S. aureus, and asymptomatic colonization is far more common than infection. Young children tend to have higher colonization rates, probably because of their frequent contact with respiratory secretions.

There are three types of environments in which cells are located which include isotonic, hypotonic and hypertonic. In an isotonic environment, the amount of water and solute are the same both inside and outside of the cell. As water drifts into the a cell, the same amount flows out creating a balanced environment both inside and outside of the cell. When there is a high level of water on the outside of the cell and a high amount of solute inside the cell, water will be drawn inside of the cell creating a hypotonic solution. The increase in water inside the cell causes the cell to become engorged and erupt. In a

However, everybody who has contact with the patient or the environment is entitled to relevant information that will enable them to reduce the risks of transmission to

|EMB Agar | |Distinguishes bacteria that ferment |Dark blue colonies with|E. coli and P. |

The Staphylococcus aureus bacteria belongs to the Staphylococcaceae family. It is small, round shaped, and non-motile. Staphylococcus aureus stains gram positive and can often be found in small clusters (Mandal, 2010). It often forms chains and is a large contributor of soft tissue infections. It is of a yellow color, hence the name ?aureus? which comes from the Latin term ?aurum? for gold (Orenstein, n.d.). Staphylococcus aureus is found in a few spots on the human body, such as the nasal passage, the skin, the oral cavity, and even the gastrointestinal tract. Staphylococci and Streptococci are two different strands of the bacteria and are very hard to distinguish from one another. In order to tell the difference between them, without a microscope, a catalase test needs to be performed. The test is undergone by adding 3% hydrogen peroxide to both samples. Since Staphylococci are catalase positive, meaning they produce catalase, they will produce O? while the Streptococci will not because Streptococci are catalase negative (Todar, n.d.).

Microorganisms are both beneficial and harmful. These microorganisms are important to humans because they play a role in the ecology of life, by decomposing wastes, both natural and man-made, such as creating nitrogen fertilizer at the root zones of certain crops. Other several pathogens that can cause serious harm, even immediate death due to the diseases or disease causing products they produce. Overall, microorganisms play an important role in life.

BSP, S. (2010). How is EM different from light microscopy? Retrieved April 25, 2015, from http://bsp.med.harvard.edu/node/222

MRSA which is short for Methicillin Resistant Staphylococcus Aureus is a staph or skin contamination that is resistant to a part of the most grounded anti-toxins. At the point when Methicillin Resistant Staphylococcus Auereus was initially found a few years prior when it spread in many healing centers and after that into the group, this contamination was known as one of the primary diseases to be resistant to the most effective anti-microbials. Staph contaminations have been referred to following the mid twentieth century as one of the deadliest infections. Staphylococcal contaminations are maladies brought about by various staphylococcal microscopic organisms. Twenty to thirty percent of all sound people get this contamination in the

The effectiveness of disease treatment is often presented by the challenge of antimicrobial resistance. Cystic Fibrosis (CF) for example, is a pulmonary infection characterized by the poly-microbial growth of bacteria within biofilms, in the pulmonary tract of humans. For children suffering from CF, Staphylococcus aureus (S. aureus) initially colonizes their airways, which with age, becomes replaced by Pseudomonas Aeruginosa (P. aeruginosa). The eradication of P. aeruginosa by antibiotics fails in 10-40% of CF patients. In the article, it was proven that there existed an interaction between the staphylococcal protein A (SpA) from S. aureus filtrates (SaF, a bacterial supernatant of S. aureus), and an exopolysaccharide (Psl) of P. aeruginosa. This interaction lead to the aggregation and increased resistance to tobramycin¬ – an antibiotic used to eradicate P. aeruginosa, to prevent chronic colonization of the bacteria. The study conducted involved 7 samples of P. aeruginosa that were taken from individuals who underwent successful eradication treatment, and 7 samples from individuals who still had persistent isolates. These P. aeruginosa samples were cultured for 24 hours in media. When SaF was added to the overnight preformed biofilms, the eradicated isolates were not affected by the SaF; however, the persistent isolates showed significant reduction is surface coverage due to densely packed cellular aggregation, without affecting the biomass or viability of persistent isolates. The

Methicillin Resistant Staphylococcus Aureus (MRSA) is a strain of staph bacteria which has developed resistance to the antibiotics designed to treat common staph infections (Winterstein, 2009, p.189). Originally viewed as a hospital pathogen, MRSA has now begun to appear in the community. Hence, the infection is now distinguished by its origin, defined as hospital-associated MRSA (HA-MRSA), or community-associated MRSA (CA-MRSA). The close proximity of athletes, who often share soap, towels, and other items commonly used in the dressing room, as well as the vigorous physical contact involved in sporting activity (both practice and competition), have led to MRSA becoming a concern in athletics. MRSA is a concern because it can lead to severe infection and even morbidity (Indeed, athletes have become a target population for MRSA. A recent study of 377 varsity college athletes at Vanderbilt University confirms that those involved in contact sports were more than twice as likely to carry MRSA (Jiminez-Truque, 2014). It is believed that the higher prevalence of MRSA in contact sports is a result of the increased skin-to-skin contact which can lead to abrasions and cuts, which permit the superbug to enter the body and colonize it (Jiminez-Truque, 2014). Treatment of MRSA involves draining of abscesses, combined with administration of powerful antibiotics, usually intravenously (Winterstein, 2009, p.187). Since MRSA is resistant to the antibiotics developed to treat it

Staphylococcus aureus (S. aureus) is an opportunistic Gram-positive bacterium that cause varied human diseases such as skin infection, pneumonia, Toxic Shock Syndrome and bacterimia. 1/2 As time passes by, resistance strains of S.A appeared and with the recent emerge of methicillin and vancomycin resistance strains, S.A treatment become a truly challenging task now. 3/4 Numerous strategies S.A adopt to help achieving its resistance abilities such as exoenzymes, exotoxins, surface associated adhesion and capsular polysaccharide (CP). 93

Virulence Factors: The most important virulence factor of S. aureus is the specific surface proteins that allow the organism to attach to host proteins. The surface proteins of this bacterium allow it to attach to host proteins such as laminin and fibronectin, which form the extracellular matrix of epithelial and endothelial cells. S. aureus also produces a number of membrane damaging toxins that allow the organism to further invade and harm the host, of which the alpha- toxin is the most well studied and is the protein responsible for septic shock. The alpha- toxin is a protein that binds to a specific receptor in platelets and monocytes in humans, forming pores that eventually destroy the cell.

2. Introduction: Each student was given unknown bacteria and was instructed to perform a variety of experimental tests that would help to identify their bacteria. During the process of identification, the unknown bacteria was added to many different testing medias using aseptic technique. They are as follows: lactose fermentation on eosin methylene blue (EMB), TSI (Triple Sugar Iron agar), Phenol red sucrose, the SIM test, H2S by SIM, IMViC (indole, motility, voges-proskauer, and citrate), Urease (urea broth), PDase (Phenylalanine Deaminase), Lysine Decarboxylase, and Ornithine Decarboxylase. Colonial morphology on EMB was used to

The law proves that natural selection is necessary for evolution to occur ("SparkNotes: population genetics," 2014). The conditions set up by the Hardy-Weinberg Law allow for variability (the existence of different alleles) and inheritance, but they eliminate natural selection ("SparkNotes: population genetics," 2014). The fact that no evolution occurs in a population meeting these conditions proves that evolution can only occur through natural selection ("SparkNotes: population genetics," 2014). The Hardy-Weinberg Law allows us to estimate the effect of selection pressures