Staphylococcal infections are communicable conditions caused by specific bacteria. Infections from Staphlococcus frequently cause the formation of abscesses. Staph is the leading cause of nosocomial (hospital-acquired) infections in the United States. Staph exists on the skin and/or in the nostrils of 20-30% of healthy people. It is also sometimes found in the breast tissue, the mouth, and also in the genital, urinary, and upper respiratory tracts. Some people carry Staph in throat, vagina, or rectum without ever becoming ill.
Staph is normally harmless, but when it gets in the bloodstream through a break in the skin it can cause serious infections and even death. The risk of staph infection is highest in newborns, women who are breastfeeding, intravenous drug users, people with surgical incisions, skin disorders, or people with serious illnesses such as cancer, diabetes, or lung disease. Also, people with compromised immune systems, trauma and burn patients, patients that receive an implanted medical device or prosthetic, long term care patients, kidney dialysis patients, and patients undergoing invasive outpatient procedures are at high risk for an infection.
Staphylococcus aureus is gram positive (stains purple to blue on gram stain), forms clusters, is hemolytic (causes lysis of RBCs) on blood agar, and forms yellow colonies on rich media. It is also a facultative anaerobe, which means it can use oxygen (aerobic respiration) or fermentation (yielding lactic acid) to make ATP. S. aureus is oxidase negative which means that it shows negative results on a BBL Dryslide Oxidase test which detects the presence of cytochromes. It can grow at temperatures of 15-45 degrees Celsius. S. aureus is also catalase positive, or it produces catalase which breaks down hydrogen peroxide to water and oxygen.
The Essay on Dangers Of Tattooing Infection Tattoo People
The Dangers of Tattoos Many people think that tattooing is dangerous. Part of this is because people don't think that the tattoo artists sterilize their materials. Others believe that tattoos have a high risk of infection. And the most commonly reported problems are allergic reactions. Others feel as though the pain factor is too immense. Although these fears are common they are easily prevented. ...
It is non-motile, non-sporeforming, and ferments glucose with the production of lactic acid. S. aureus is coagulase positive-coagulase is an extracellular protein that converts fibrinogen to fibrin, which is involved in blood clotting. It is found in the normal flora of nasal passages, skin, and mucous membranes, without causing ill effects. S. aureus can also cause food poisoning. There are many manifestations of Staph infections. Infections produce pus-filled pockets (abscesses) below the surface of the skin or deep within the body. Abscesses usually burst and the pus that gets on the skin can cause new infections.
A localized infection usually consists of a ring of dead or dying white blood cells and bacteria. The skin above the infection usually feels warm to the touch. Part of a localized Staph infection can enter the bloodstream. In children, these invasive infections affect the ends of long bones of the arms and legs, which can cause osteomyelitis, or an infection of the bone or bone marrow. In adults, invasive infections can cause abscesses of the brain, kidneys, heart, liver, lungs and spleen. MRSA stands for methicillin-resistant Staphylococcus aureus. MRSA is resistant to antibiotics called beta-lactams.
A beta-lactam is a cyclic amide that inhibits cell wall synthesis of bacteria, and the resistance from MRSA comes from its production of beta lactamase, an enzyme that breaks down beta-lactams. Other beta-lactams include oxacillin, amoxicillin, penicillin, cephalosporins, carbapenems, and monobactams. Only about 1% of people are actually colonized with MRSA. People with potential or active bloodstream infections are treated with Vancomycin, Linezolid, or Daptomycin. There are a few types of infections caused by MRSA. MRSA is most prevalent in hospitals and other healthcare settings.
Surgical wound infections, urinary tract infections, bloodstream infections, and pneumonia are most common. These infections seriously increase costs and mortality rates in hospitals. In 2005, hospital studies show that MRSA occurred in nearly one percent of all hospital stays. MRSA infections increased the length of a hospital stay by three times, which in turn caused costs to increase by three times. The risk of hospital death was increased by five times. These numbers translate to 2. 7 million days in excess length of stay, 9. 5 billion dollars in excess charges, and about 12,000 excess inpatient deaths a year.
The Term Paper on Infection control and universal precautions
The principle of infection control is something that is becoming increasingly important in hospitals and healthcare settings. This is primarily because of the hardship and suffering it causes to the patient who acquires an infection whilst in hospital and also because of the cost it brings to our already under funded hospitals from increased stays and healthcare workers falling ill. The author ...
Statistics are very consistent in hospitals throughout the country. MRSA can be spread in several ways including: hand carriage, contaminated surfaces, medical instruments, airborne particles, needles, sexual intimacy, and shared items such as hygiene items (towels, etc. ) Nasal swabs are now commonly used in hospitals to detect colonized people. In surgery patients, a nasal treatment and skin wash are now used as a preventative measure. In fact, no one is exempt from Staph infections. The National Football League has been plagued with Staph infections in the past few years.
Two high-profile players that contracted Staph after surgery in 2008 are Tom Brady (New England Patriots) and Peyton Manning (Indianapolis Colts).
Tom Brady has had at least two additional procedures in addition to his season-ending knee surgery last September due to a Staph infection. The infection could possibly keep Tom Brady off of the field until 2010. MRSA is a very virulent bacterium, and this is due to a few factors. MRSA has developed drug resistance by mutations in its genome by selection of resistant strains and acquisition of plasmids, transducing particles, transposons, and other DNA inserts that act as virulence genes.
Staphylococcus aureus since the 1940’s (when penicillin was introduced) has steadily been quick to adapt to new drugs. Pharmaceutical companies are currently attempting to find a new drug that may block certain molecular targets such as active sites for enzyme binding to combat emerging strains of S. aureus. Recently a plasmid associated with Vancomycin resistance has been found in enterococci that can be transferred to S. aureus in the lab. This is significant because this may occur in the GI tract between the normal flora and S. aureus. There is a slight possibility for a vaccine against MRSA.
There is currently no vaccine available against MRSA. However, the mechanism for host binding is known. Therefore, an inhibitor could potentially be made to block the interaction of MRSA and its host which would prevent colonization. Clinical trials for a vaccine against S. aureus called StaphVAX are ongoing. The vaccine is S. aureus type 5 and 8 capsular polysaccharides conjugated with nontoxic recombinant Pseudomonas aeruginosa exotoxin A. The vaccine gives immunity for 40 weeks, which is ideal for surgery patients. Statistics regarding Staph infections are quite astounding.
The Essay on Skin Cancer Cells Body Called
Skin Cancer Cancer is a word used to describe a group of diseases. Each has its own name, its own treatment, and its own chances of being cured. Each is different from the others in many ways, but every cancer, whatever its called or whatever part of the body it is located in, is a disease of the body's cells. The millions of tiny cells that make up the human body are so small that they can be ...
Staph has been a problem in the United States for over half a century. It is the number two most common nosocomial infection behind Gram-negative bacilli. Staph bacterimia has a mortality rate of 11-43%. 25-35% of Staph complications are from endocarditis or an inflammation of the inner layer of the heart, with a mortality rate of 20-44%. Nosocomial infections are the eighth leading cause of death in the U. S. The number of MRSA infections doubled between 1987 and 1997 in intensive care units. Staph infections can cause many minor complications in the body.
As previously mentioned, Staph infections cause abscesses, but they can also cause other minor complications such as folliculitis of the hair follicle, usually shaving irritation or chaffing from clothing, boils which are a deeper infection of the hair follicle, usually on the face or neck, styes or infection of the eyelash hair follicle, and impetigo or blisters and red, scabby skin, usually on children’s noses and mouths. There are a few key warning signs of a Staph infection such as pain or swelling around a cut or scrape. Boils or skin abscesses are also a red flag.
Other signs include blistering, peeling, or scaling of the skin, particularly in children, and enlarged lymph nodes around the armpits, neck or groin area. There are several more serious problems associated with S. aureus infections. Some of these have already been mentioned. They include toxic shock syndrome, pneumonia, bone infections or osteomyelitis, mastisis in nursing mothers, endocarditis, bacteremia or a blood infection, nosocomial infections of surgical wounds, infections associated with indwelling medical devices, scalded skin syndrome, and septic shock.
Toxic shock syndrome can occur through the pharynx, skin, or vagina. The symptoms include fever, rash, low blood pressure, malaise or confusion, and multi-organ system failure. Mastisis is an inflammation of the parenchyma of the mammary gland. Scalded skin syndrome causes a bright red rash on the skin and then forms scales. Large blisters then form and when they burst, the skin appears burned. It is most common in children under the age of five. Septic shock causes decreased tissue perfusion and oxygen delivery as a result of infection.
The Essay on A Nucleus Day Cell Control Proteins
Matthew Williams Nucleus for a Day Wow, another exciting day is about to begin. Sometimes I get so tired of being the brains of this whole operation, but it is fun to be the boss and give the orders. Let? s examine a typical day: I am the nucleus. My life is very complicated because there are constantly things going on and I hardly have time to talk to you. But since I started telling you about ...
Just about any prosthetic or indwelling medical device such as a pacemaker, cochlear implant, dental implant, dialysis shunt, artificial leg, intraocular lens, etc can potentially cause an MRSA infection. S. Epidermidis is another strand of Staph that is important in a hospital setting. It is capable of clinging to non-living surfaces, so it can contaminate devices that have direct access to the bloodstream. It is the primary cause of nosocomial bacteremia and a common cause of prosthetic valve endocarditis. It is most common in cancer patients and newborns with compromised immune systems.
Understanding the pathogenicity of S. aureus is very important to understanding the bacteria. S. aureus has many cell surface-associated and extracellular proteins that are potential virulence factors. In order for an organism to cause an infection, the pathogen must gain access to the host cell. S. aureus has proteins such as laminin and fibronectin as part of its extracellular matrix that promote binding to host cells. Fibronectin is located on endothelial and epithelial surfaces and is a component of blood clots.
Most strains of S. aureus also have a fibrinogen/fibrin binding rotein that promotes attachment to clots and traumatized tissues. S. aureus displays a number of virulence factors associated with its pathogenicity. Strains of Staph that cause septic arthritis and osteomyelitis have been shown to have receptors that promote attachment to collagen. This is important especially in promoting bacterial attachment to damaged tissue where underlying layers have been exposed. Also, Staphylococcus aureus can adhere to endothelial cells and become internalized by a phagocytic-like process. Endothelial cells line blood vessels and are simple squamous epithelium.
The Essay on Metabolism: Cell Membrane And Protein Synthesis
Kinetic energy is energy in action, while potential energy is stored energy. Structurally variant atoms, which have the same number of protons (and electrons), but differ in the number of neutrons they contain Atomic weight of an element is approximately equal to the mass number of its most abundant isotope. is based on the concentration of H+ ions. Which of the following is not a subatomic ...
It is not currently known whether the receptor responsible for attachment is a novel one or if it is a known part of Staph’s protein surface. Staph is thought to be able to attach even to undamaged endothelial cells. S. aureus also expresses some mechanisms that interfere with host’s defenses. Protein A is a protein expressed by S. aureus that binds IgG (immunoglobulin G) by the Fc region (the ‘tail’ of an antibody).
Due to this binding, antibodies do not activate the immune system, and opsonization and phagocytosis are suppressed, which allows the bacteria to flourish. This is known as a non-immune mechanism.
Mutants of Staph that do not have protein A are more likely to be phagocytized. One toxin (leukocidin) that is expressed by S. aureus can act specifically on polymorphonuclear leukocytes (aka PMNs or granulocytes).
PMNs are a type of white blood cell characterized by the varying shapes of their nucleus. Leukocidins are cytotoxins that destroy leukocytes by causing membrane damage. This prevents phagocytosis which is extremely important in the immune response.
Therefore, leukocidin is another virulence factor of S. aureus. Leukocidin is not hemolytic. The most potent membrane-damaging toxin of S. aureus is ? toxin. It is usually expressed as a monomer and binds to susceptible cell membranes. Next subunits of ? -toxin oligomerize and form hexameric rings. These form pores in the membrane, and cellular contents are able to leak through these pores. Certain cells have a specific receptor for the ? -toxin, and low concentrations are allowed to bind and form the aforementioned pores through which monovalent cations can pass. At higher concentrations, ? toxin can bind non-specifically to membrane lipids which creates pores large enough for divalent cations to pass though. This probably does not occur in normal conditions.
Platelets and monocytes in humans are very sensitive to ? toxin. This allows the toxin to bind in concentrations that are physiologically relevant. The secondary reactions caused by the binding of ? toxin cause the release of eicosanoids (work in inflammation and immunity) and cytokines (signaling molecules in cellular communication).
The Term Paper on The Different Types of Cells
There are three major parts of a cell-- the nucleus, cytoplasm, and cell membrane, if these are stained appropriately, they can be easily seen under a light microscope. The nucleus (in many cell types) is the innermost and is enclosed by a thin membrane. The nucleus contains the genetic material which directs the cells function. The cytoplasm includes specialized structures called cytoplasmic ...
This triggers production of inflammatory mediators. These reactions cause the symptoms of septic shock which occurs during serious infections by S. aureus. ?-toxin is a sphingomyelinase, which is an enzyme that degrades sphingomyelin.
Sphingomyelin is a common constituent of cell membranes. -toxin is not commonly found in human isolates of S. aureus, however, it is frequently found in isolates from bovine mastisis. This suggests that it could be important in the pathogenicity of mastisis. In addition, ? -toxin is an extremely small peptide toxin that is found in most strains of S. aureus. ?-toxin is also produced by S. epidermidis and S. lugdunensis. The role of this toxin in disease is unknown. Another toxin includes ? -toxin and leukocidins are component protein toxins that damage cell membranes. These two proteins are expressed separately but work together to damage membranes.
There is no evidence that these proteins form multimers before inserting themselves into cell membranes. The ? -toxin locus expresses 3 subunits. The B and C subunits form a leukotoxin that is weakly hemolytic. The A and B subunits are strongly hemolytic with little leukotoxic ability. Superantigens are secreted proteins that have highly potent lymphocyte-transforming ability directed towards T-lymphocytes (important in cell-mediated immunity).
S. aureus expresses two toxins with superantigen ability: enterotoxin and toxic shock syndrome toxin. There are 6 serotypes of enterotoxin: A, B, C, D, E, and G.
Toxic shock syndrome toxin is abbreviated TSST-1. Enterotoxins cause diarrhea and vomiting, and they are responsible for food poisoning sometimes associated with S. aureus infections. When expressed systemically, enterotoxins can cause toxic shock syndrome (mostly non-menstrual associated).
TSST-1 is somewhat related to entertoxins and does not have emetic activity. Superantigens stimulate T cells non-specifically without normal antigenic recognition. In normal antigen presentation, about 1 in 10,000 T cells are activated. With superantigens, up to 1 in 5 T cells may be activated.
This causes a large amount of cytokines to be released, which causes the symptoms of TSS. Superantigens bind directly to class II major histocompatibility complexes of antigen presenting cells outside the normal antigen-binding groove. The complex only recognizes the Vb element of the TCR. This eliminates the usual need for antigen specificity in binding to the T cell, therefore, any T cell with the appropriate Vb element will be bound. Coagulase is an extracellular protein that combines with prothrombin in the host which forms staphylothrombin. The protease activity of thrombin is activated, and fibrinogen is converted to fibrin.
Coagulase is important because it is the traditional marker for identifying S. aureus in the laboratory. However, coagulase does not appear to be a virulence factor. Several strains of S. aureus express a plasminogen activator-staphylokinase. Staphylokinase and plasminogen form a complex which activates plasmin-like proteolytic activity (degradation of proteins) which in turn causes the breakdown of fibrin clots. Staphylokinase has not been shown to be a virulence factor, however it seems likely that this mechanism could aid in spreading of the bacteria. S. ureus can express a protease, a deoxyribonuclease (DNase), a lipase, and a fatty acid modifying enzyme (FAME).
All but FAME probably just provide nutrients for the bacteria.
FAME may be important in formation of abscesses because it could modify anti-bacterial lipids which would prolong bacterial survival. According to the Health Plan of Nevada MRSA guidelines, an MRSA infection must first be classified as community-acquired or hospital-acquired. If the wound is superficial without signs of infection, it may be treated with the use of oral or IV antibiotics. The wound should regularly be cleansed with Hibiclense.
A topical application of a silver dressing such as Acticoat or Silvasorb should be used. The wound should also be closely monitored for signs of infection. For a superficial skin and soft tissue infection, local wound cleansing should be paired with antibiotic therapy. The antibiotic treatment must be for at least ten days but may vary depending on the severity of the infection. Antibiotic choices may include: Trimethoprim-sulfamethoxazole, Minocycline or Doxycycline, or Rifampin. Rifampin must be used in combination with one of the other antibiotics, and it may never be used alone due to rapid development of resistance.
If one of the previously mentioned antibiotics fails, Zyvox is another treatment option. Zyvox patients must be carefully monitored for Myelosuppression, which has symptoms of anemia, leukopenia, pancytopenia, and thrombocytopenia. Complex skin and skin structure infections (hospital-acquired) are treated with aggressive debridement of necrotic and infected skin and deep soft tissue structures. Peripheral vascular sufficiency should be established immediately to rule out peripheral vascular disease. Once MRSA has been positively identified, Zyvox can be used for 2 to 3 weeks.
If the infection requires more than 3 weeks of therapy, Vancomycin intravenously with close monitoring of BUN (blood urea nitrogen-check for renal function) and creatinine (from breakdown of creatine phosphate-also a check for renal function) levels. Osteomyelitis, or infection of bone and/or bone marrow, is treated with aggressive surgical resection of bone and soft tissue. Peripheral vascular sufficiency should be established immediately. When MRSA is identified, the patient should be placed on a 6 week course of Vancomycin, and BUN and creatinine levels must be closely monitored.
Zyvox can be used as an alternative in cases of renal insufficiency. MRSA has been a burden to hospitals across the country. Many are taking extreme measures to try and prevent infections. For example, at the University of Maryland Medical Center in Baltimore more than 1/3 of the patients are repeatedly tested for MRSA throughout their hospital stays. At Johns Hopkins Hospital employees are getting weekly numbers on possible transmissions. Alcohol-based hand gels are being used in increasing numbers. Washington Hospital Center is now providing routine screenings for at-risk patients.
A major fear of hospitals now is that new strains of MRSA are going to become entrenched in hospitals. Many states such as Virginia are calling statewide conferences to discuss ways to tackle MRSA. In conclusion, MRSA is a dangerous bacterium that can cause serious and even life-threatening infections. Hospitals are grappling to handle the superbug, and new strains are constantly emerging. With no current vaccine available, healthcare workers must keep hospital environments as safe and clean as possible to prevent MRSA from spreading.