Pseudomonas Aeruginosa Essays - Gram-negative Bacteria,

Pseudomonas Aeruginosa Pseudomonas aeruginosa Research Paper Julie Johnson Pseudomonas aeruginosa is a versatile gram negative bacterium that grows in soil, marshes, and coastal marine habitats, as well as on plant and animal tissues. People with cystic fibrosis, burn victims, individuals with cancer, and persons infected with HIV are particularly at risk of disease resulting from Pseudomonas aeruginosa. Unlike many environmental bacteria, Pseudomonas aeruginosa has a remarkable capacity to cause disease in susceptible hosts. It has the ability to adapt to and thrive in many ecological niches, from water and soil to plant and animal tissues. The bacterium is capable of utilizing a wide range of organic compounds as food sources, thus giving it an exceptional ability to colonize ecological niches where nutrients are limited. Pseudomonas aeruginosa can produce a number of toxic proteins, which not only cause extensive tissue damage, but also interfere with the human immune systems defense mechanisms. These proteins range from potent toxins that enter and kill host cells at or near the site of colonization to degradative enzymes that permanently disrupt the cell membranes and connective tissues in various organs. In people with cystic fibrosis the most serious complication is respiratory tract infection by the ubiquitous bacterium Pseudomonas aeruginosa. CF is one of the most common fatal genetic disorders in the United States, affecting about 30,000 individuals. A comparable number of people in Europe also have CF. It is most prevalent in the Caucasian population, occurring in one of every 3,300 live births. The gene involved in cystic fibrosis was identified in 1989. Located on human chromosome 7, it codes for a protein called the cystic fibrosis transmembrane conductance regulator (CFTR). This protein, normally produced in a number of tissues throughout the body, regulates the movement of salt and water in and out of these cells. The abnormality in the CFTR gene alters the CFTR protein in people with cystic fibrosis. As a result, one hallmark of CF is the presence of a thick mucus secretion which clogs the bronchial tubes in the lungs and plugs the exit passages from pancreas and intestine s, leading to loss of function of these organs. Progressive lung disease is the predominant cause of illness and death in people with CF. Mucus blocks the airway passages and results in a predisposition toward chronic bacterial infections. Although the genetic defect underlying CF has been characterized, exactly how and why individuals become infected with Pseudomonas is unknown. The lungs of most children with CF become colonized by Pseudomonas aeruginosa before their 10th birthday. Chronic infection with these bacteria reduces an individuals quality of life, causing acute symptoms of cough, sputum production, and inflammation, which causes repeated exacerbations or episodes of intense breathing problems. Eventually leading to scarring and destruction of lung tissue and, ultimately, death. While it is clear that antibiotic therapy directed against these organisms lengthens the life span of individuals with CF, increasing antibiotic resistance develops. Although antibiotics can decrease the frequency and duration of these attacks, the bacterium establishes a permanent residence and can never be completely eliminated from the lungs. Management of cystic fibrosis lung disease requires a multipronged approach. Outpatient management of pulmonary exacerbation usually includes a combination of 2 IV antipseudomonal antibiotics (an aminoglycoside plus a beta-lactam), appropriate antimicrobial treatment, effective airway clearance, optimization of nutritional status, and anti-inflammatory therapies. Additionally, prevention of respiratory viral disease and avoidance of exposure to irritants, such as smoke, is recommended. Usual duration of therapy is 14 to 21 days, and clinical response is assessed by physical exam, pulmonary function tests, nutritional status, and exercise tolerance. Microbial eradication is not a therapeudic end point. Choice of antibiotics should be based on culture and sensitivity of the sputum. Emergence of antibiotic-resistant species, such as Pseudomonas aeruginosa, has required close monitoring of antibiotic susceptibility patterns and strict infection-control policies. Administration of chronic intermittent inhaled antipseudomonal therapy (tobramycin solution for inhalation), over a 6 month period was shown to improve FEV by 11.9%, decrease the bacterial density, and reduce hospitalization in CF patients chronically infected with Pseudomonas aeruginosa. Following 92 weeks of therapy with inhaled tobramycin, the mean % change in FEV was 4.7% above baseline. There was no increase in the utilization of antipseudomonal therapy despite an increase in MIC at

Using a Sample GRE Essay Question to Improve Your Score

Using a Sample GRE Essay Question to Improve Your ScoreYou can use a sample GRE essay question to help you find out how well you are doing. This is a method that can really help you improve your scores and is also one of the best ways to get feedback on what you need to work on if you haven't taken the test.It is important to remember that all of the GRE practice questions you use should come from the same sample. Not only will this make your scores better, but it will also give you a good idea of what areas of your writing you need to focus on. There are many different tips for finding a good practice GRE question and most of them revolve around taking the test as many times as possible to get a feel for the format.Many students find that it helps to take the exam multiple times because they find the format of the test is too confusing for just one time. This way, they have the opportunity to look at a number of different topics and learn how to prepare their answers based on the fo rmat. Most of the questions involve testing how well you can organize a response.It is very important to write out each of the essay questions you encounter so that you have a written solution for each of them. Taking the exam multiple times can cause the questions to be too hard to read and most students find that it is easier to just mark the answer incorrectly than to try to think of the right answer. This way, they can just concentrate on getting the question right.The most common question you will encounter when studying for the GRE is the 'Shoot the Pilot' question. This is when you are asked to present an argument for why a specific thesis statement should be accepted. In order to get the highest score possible, you will need to use examples and supporting evidence.Using a sample GRE essay question to help you study is an excellent way to prepare for this question because you are given many different examples to work with. This allows you to use your own information as well a s other people and come up with a convincing argument.A sample GRE essay question that most students find useful is the 'Find out how well you do on exam days'. This question asks you to identify how well you perform on exam days and this is the most commonly used test format. If you're not aware of what a typical test may consist of, you should take a look at sample GRE questions before you take the test.Since the passage that is studied for the GRE includes a number of very long and difficult questions, it is possible to come across something you are confused about. Studying for this type of question on the internet can help you see the question and answer. This will allow you to go back to the sample and figure out the correct answer before sitting down to take the actual test.