Staphylococcus aureus (which is occasionally given the nickname golden staph) is a bacterium, frequently living on the skin or in the nose of a healthy person, that can cause illnesses ranging from minor skin infections (such as pimples, boils, and cellulitis) and abscesses, to life-threatening diseases such as pneumonia, meningitis, endocarditis and septicemia. Each year some 500,000 patients in American hospitals contract a staphylococcal infection. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Classes Bacilli Clostridia Mollicutes The Firmicutes are a group of bacteria, most of which have Gram-positive stains. ... Orders Bacillales Lactobacillales The term bacilli (singular bacillus) is used to refer to any rod-shaped bacteria. ... Families Alicyclobacillaceae Bacillaceae Caryophanaceae Listeriaceae Paenibacillaceae Planococcaceae Sporolactobacillaceae Thermoactinomycetaceae The Bacillales are an order of Gram-positive bacteria, placed within the Firmicutes. ... Species S. aureus S. caprae S. epidermidis S. haemolyticus S. hominis S. lugdunensis S. saprophyticus S. warneri S. xylosus Staphylococcus (in Greek staphyle means bunch of grapes and coccos means granule) is a genus of gram-positive bacteria. ... In biology, binomial nomenclature refers to the formal method of naming species. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... An infection is the detrimental colonization of a host organism by a foreign species. ... Acne of a 14 year old boy during puberty. ... Boil or furuncle is a skin disease caused by the inflammation of hair follicles, thus resulting in the localized accumulation of pus and dead tissues. ... An abscess is a collection of pus collected in a cavity formed by the tissue on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e. ... A disease is any abnormal condition of the body or mind that causes discomfort, dysfunction, or distress to the person affected or those in contact with the person. ... Pneumonia fills the lungs alveoli with fluid, keeping oxygen from reaching the bloodstream. ... Meningitis is inflammation of the membranes (meninges) covering the brain and the spinal cord. ... Endocarditis is an inflammation of the inner layer of the heart, the endocardium. ... Sepsis (in Greek Σήψις) is a serious medical condition caused by a severe systemic infection leading to a systemic inflammatory response. ...

Microbiology

Staphylococcus aureus appears as a Gram-positive coccus, in grape-like clusters when viewed through a microscope and as large, round, golden-yellow colonies, often with β-hemolysis, when grown on blood agar plates. S. aureus can be differentiated from most other staphylococci by the coagulase test. S. aureus is coagulase-positive, while most other staphylococci are coagulase-negative. S. aureus is also catalase positive and thus able to convert hydrogen peroxide (H₂O₂) to water and oxygen, which makes the Catalase test useful to distinguish S. aureus from S. faecalis. Gram-positive bacteria are those that are stained dark blue or violet by gram staining, in contrast to gram-negative bacteria, which are not affected by the stain. ... coccus (plural - cocci) are any spherical or near spherical bacteria. ... This article needs to be cleaned up to conform to a higher standard of quality. ... An agar plate streaked with microorganisms isolated from a deep-water sponge. ... Coagulase is an adhesin (EC 3. ... link title Catalase Catalase (human erythrocyte catalase: PDB 1DGF, EC 1. ... Hydrogen peroxide (H2O2) is a clear liquid, slightly more viscous than water, that has strong oxidizing properties and is therefore a powerful bleaching agent that has found use as a disinfectant, as an oxidizer, and (particularly in high concentrations as high test peroxide (HTP)) as a monopropellant in rockets. ...

The species has been subdivided into two subspecies: S. aureus aureus and S. aureus anaerobius. The latter requires anaerobic conditions for growth, is an infrequent cause of infection, and is rarely encountered in the laboratory.

Antibiotic sensitivity

S. aureus has become resistant to many commonly used antibiotics. Up to 20% of all Staphylococcus isolates are resistant to penicillin, which has led to the introduction of flucloxacillin and cloxacillin as first-line antistaphylococcal antibiotics. Antibiotic resistance is the ability of a microorganism to withstand the effects of an antibiotic. ... Penicillin is a β-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually Gram-positive, organisms. ... Cloxacillin is a semisynthetic antibiotic in the same class as penicillin. ...

An increasing problem since the 1950s has been resistance of S. aureus to flucloxacillin, oxacillin, and similar β-lactam antibiotics that are deactivated by β-lactamase. As methicillin is used in laboratories to assess for this type of resistance, the term Methicillin-resistant Staphylococcus aureus (MRSA) is in use to denote these strains. MRSA is generally sensitive to the glycopeptide antibiotics vancomycin and teicoplanin. // Events and trends The 1950s in Western society was marked with a sharp rise in the economy for the first time in almost 30 years and return to the 1920s-type consumer society built on credit and boom-times, as well as the height of the baby boom from returning... β-lactam antibiotics are a broad class of antibiotics including penicillin derivatives, cephalosporins, monobactams, carbapenems and β-lactamase inhibitors; basically any antibiotic agent which contains a β-lactam nucleus in its molecular structure. ... Beta-lactamase is a type of enzyme (EC 3. ... Methicillin is an antibiotic related to penicillin and other beta-lactam containing antibiotics. ... Methicillin-resistant Staphylococcus aureus, (MRSA) is a specific strain of the Staphylococcus aureus bacterium that has developed antibiotic resistance, first to penicillin since 1947, and later to methicillin and related anti-staphylococcal drugs (such as flucloxacillin). ... Vancomycin is an antibiotic used in the prophylaxis and treatment of infections caused by Gram-positive bacteria. ... Teicoplanin is an antibiotic used in the prophylaxis and treatment of serious infections caused by Gram-positive bacteria. ...

In 1997, physicians were alarmed to encounter staph strains that resist even vancomycin, to which it had previously always been sensitive. Due to this resistance, S. aureus is sometimes referred to as a superbug. 1997 (MCMXCVII) is a common year starting on Wednesday of the Gregorian calendar. ... Vancomycin is an antibiotic used in the prophylaxis and treatment of infections caused by Gram-positive bacteria. ... Antibiotic resistance is the ability of a microorganism to withstand the effects of an antibiotic. ...

Staphylococcal resistance to penicillins and cephalosporins is expressed as beta-lactamase production: enzymes which break down the beta-lactam ring of the penicillin molecule. Other resistance-conferring mutations include altered penicillin-binding proteins to which penicillins bind poorly. Penicillin is a β-lactam antibiotic used in the treatment of bacterial infections caused by susceptible, usually Gram-positive, organisms. ... The cephalosporins, are a class of β-lactam antibiotics. ... Beta-lactamase is a type of enzyme (EC 3. ...

With the increased incidence of MRSA infections, vancomycin or teicoplanin (glycopeptide antibiotics) are often a treatment of choice in infections with methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin-resistant Staphylococcus aureus (VRSA) is a strain of Staphylococcus aureus that has become resistant to the glycopeptides. Three cases of VRSA infection have been reported in the United States^[1]. Vancomycin is an antibiotic used in the prophylaxis and treatment of infections caused by Gram-positive bacteria. ... Teicoplanin is an antibiotic used in the prophylaxis and treatment of serious infections caused by Gram-positive bacteria. ... Methicillin-resistant Staphylococcus aureus, (MRSA) is a specific strain of the Staphylococcus aureus bacterium that has developed antibiotic resistance, first to penicillin since 1947, and later to methicillin and related anti-staphylococcal drugs (such as flucloxacillin). ... Vancomycin-resistant Staphylococcus aureus (VRSA) is a strain of Staphylococcus aureus that has become resistant to the glycopeptide antibiotic vancomycin. ...

Role of pigment in resistance

The vivid yellow pigmentation of S. aureus may be a factor in its virulence. When comparing a normal strain of S. aureus with a strain modified to lack the yellow coloration, the pigmented strain was more likely to survive dousing with an oxidizing chemical such as hydrogen peroxide than the mutant strain was. In biology, pigment is any material resulting in color in plant or animal cells which is the result of selective absorption. ... Hydrogen peroxide (H2O2) is a clear liquid, slightly more viscous than water, that has strong oxidizing properties and is therefore a powerful bleaching agent that has found use as a disinfectant, as an oxidizer, and (particularly in high concentrations as high test peroxide (HTP)) as a monopropellant in rockets. ...

Colonies of the two strains were also exposed to human neutrophils. The mutant colonies quickly succumbed while many of the pigmented colonies survived. Wounds on mice were swiped with the two strains. The pigmented strains created lingering abcesses. Wounds with the unpigmented strains healed quickly. Neutrophil granulocytes (commonly referred to as neutrophils) are a class of white blood cells and are part of the immune system. ... An abscess is a collection of pus collected in a cavity formed by the tissue on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e. ...

These tests suggest that the yellow pigment may be key to S. aureus's ability survive immune attacks. Drugs that inhibit the bacterium's production of the carotenoids responsible for the yellow coloration may weaken it and renew its susceptibility to antibiotics. ^[2] Carotenoids are organic pigments naturally occurring in plants and some other photosynthetic organisms like algae, some types of fungus and some bacteria. ...

Role in disease

The Staphylococcus lives as a commensal on the skin and in the nose of humans and animals, as well as in the environment. It can infect other tissues when normal barriers have broken down (e.g. skin or mucosal lining). This leads to furuncles (boils) and carbuncles (a collection of furuncles). Common Clownfish (Amphiprion ocellaris) in their magnificent sea anemone (Heteractis magnifica) home. ... Model of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system; which is composed of a layer of tissues that protect underlying muscles and organs. ... Human nose in profile The Nose is a story by Gogol and an opera by Dmitri Shostakovich. ... Boil or furuncle is a skin disease caused by the inflammation of hair follicles, thus resulting in the localized accumulation of pus and dead tissues. ... A carbuncle is an abscess larger than a boil, usually with one or more openings draining pus onto the skin. ...

Staphylococcal infections can be spread through contact with pus from an infected wound, skin to skin contact with an infected person, and contact with objects such as towels, sheets, clothing, or athletic equipment used by an infected person.

Deep Staphylococcus infections can be very severe. Prosthetic joints are particularly at risk, and staphylococcal endocarditis (infection of the heart valves) and pneumonia may be rapidly fatal. Endocarditis is an inflammation of the inner layer of the heart, the endocardium. ... Pneumonia fills the lungs alveoli with fluid, keeping oxygen from reaching the bloodstream. ...

Basic handwashing techniques such as that developed by Professor G.A.J. Ayliffe, which has six steps, are effective in preventing the transmission of Staphylococcus aureus. By the use of "standard precautions", and where necessary "additional precautions", the risk of transmission can be further reduced.

Photo gallery

Staphylococcus aureus Growing on Blood Agar

Staphylococcus aureus Growing on Blood Agar (Indirect Lighting)

Staphylococcus aureus Growing on DNase Agar

Staphylococcus aureus Growing on Mannitol Salt Agar

Catalase Test on Staphylococcus aureus

Sites of infection and diseases caused by Staphylococcus aureus

Note

1. ^  Menichetti F (2005). Current and emerging serious Gram-positive infections, Clinical Microbiology and Infection, 11(Suppl 3): 22-8. PMID 15811021
2. ^  Liu GY, Essex A, Buchanan JT, Datta V, Hoffman HM, Bastian JF, Fierer J, Nizet V (2005). Staphylococcus aureus golden pigment impairs neutrophil killing and promotes virulence through its antioxidant activity, Journal of Experimental Medicine, 202(2): 209-15. PMID 16009720

External links

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Staphylococcus aureus

• Staphylococcus - Todar's Online Textbook of Bacteriology