Staphylococcus aureus bacteria

Staphylococcus aureus

Staphylococcus aureus picture s.aureus

Staphylococcus aureus on Columbia agar with 5% defibrinated sheep blood (Bio-Rad™). Individual colonies on agar are round, convex, and 1-4 mm in diameter with a sharp border. On blood agar plates, colonies of Staphylococcus aureus are frequently surrounded by zones of clear beta-hemolysis. The golden appearance of colonies of some strains is the etymological root of the bacteria's name; aureus meaning "golden" in Latin.
Methicillin-resistant strains of Staphylococcus aureus (i.e. MRSA) often have only weak or no beta-hemolysis and special cultivation media with oxacillin, mannitol and NaCl for their isolation are used. MRSA is able to grow on this media and produce colonies of certain color, depending on used pH indicator (in this picture pink).

Staphylococcus aureus may occur as a commensal on human skin; it also occurs in the nose frequently (in about a third of the population) and throat less commonly. The occurrence of S. aureus under these circumstances does not always indicate infection and therefore does not always require treatment (indeed, treatment may be ineffective and re-colonisation may occur). It can survive on domesticated animals such as dogs, cats and horses. S. aureus can infect other tissues when barriers have been breached (e.g., skin or mucosal lining). This leads to furuncles (boils) and carbuncles (a collection of furuncles). In infants S. aureus infection can cause a severe disease Staphylococcal scalded skin syndrome (SSSS). Deeply penetrating S. aureus infections can be severe. Prosthetic joints put a person at particular risk for septic arthritis, and staphylococcal endocarditis (infection of the heart valves) and pneumonia, which may be rapidly spread.

Abbreviated from Wikipedia.

Staphylococcus aureus basic characteristics

  • GRAM-POSITIVE COCCI IN CLUSTERS
  • NONMOTILE
  • NON-SPORE-FORMING
  • CATALASE: POSITIVE
  • OXIDASE: NEGATIVE
  • FACULTATIVELY ANAEROBIC

Identification of Staphylococcus aureus

  • production of coagulase (free coagulase)
  • presence of clumping factor (cell-bound coagulase)
  • sodium chloride tolerance (7.5%)
  • mannitol fermentation
  • hyaluronidase production (positive decapsulation test with S.equi)

Antibiotic treatment of Staphylococcus aureus infections

Should be always guided by in vitro susceptibility tests!!
Selection of appropriate antibiotics depends on diagnosis!!

IF SUSCEPTIBLE:

Staphylococcus aureus colonies on agar cultivation media

Staphylococcus aureus on blood agar

staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus colony of staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus

Staphylococcus aureus beta-hemolysis

staphylococcus aureus hemolysis on blood agar s.aureus on CAP agar staphylococcus aureus staphylococcus aureus staphylococcus aureus detail of staphylococcus aureus colonies with beta hemolysis on blood agar staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus coagulase positive and negative staphylococcus colonies of staphylococcus on blood agar

Staphylococcus aureus yellow pigment

staphylococcus aureus on brain heart infusion agar staphylococcus aureus chocolate agar s.aureus growth on Schaedler agar s.aureus pigment on TSA agar staphylococcus aureus colonies on TSA staphylococcus aureus yellow colonies colony of staphylococcus aureus and streptococcus agalactiae bacteria staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus s.aureus colonies on chocolate agar

Staphylococcus aureus without yellow pigment (staphyloxanthin)

nonpigmented s.aureus colonies white non pigmented staphylococcus aureus

Clumping factor (cell-bound coagulase) and free coagulase

detection of the bound coagulase

Natrium chloride tolerance (7.5-10%) and mannitol fermentation

colonies of staphylococci on mannitol salt agar s.aureus and s.epidermidis appearance on mannitol salt agar

Lecithinase production and lipase activity on Baird Parker agar

staphylococcus aureus on Baird Parker agar appearance of staphylococcus aureus and s.epidermidis on Baird Parker agar

Hyaluronidase production (decapsulation test with S.equi ssp. zooepidemicus)

hyaluronidase production by staphylococcus aureus decapsulation test with staphylococcus aureus

Staphylococcus aureus MRSA

staphylococcus aureus staphylococcus aureus staphylococcus aureus staphylococcus aureus MRSA staphylococcus aureus Methicillin-resistant Staphylococcus aureus (MRSA)

Staphylococcus aureus biofilm formation

staphylococcus aureus bacterial biofilm bacterial biofilm formed by s.aureus SEM

Staphylococcus aureus Gram-stain

staphylococcus aureus staphylococcus aureus,escherichia coli cocci in grape-like clusters Gram-stain Gram staining technique

Useful Links

WIKIPEDIA
CENTERS FOR DISEASE CONTROL AND PREVENTION (CDC)
E-MEDICINE
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