Morphology & Cultural Characteristics of Staphylococcus aureus

MORPHOLOGY AND CULTURE CHARACTERISTICS OF STAPHYLOCOCCUS AUREUS

MORPHOLOGY OF STAPHYLOCOCCUS AUREUS

  • Shape – Round shape (cocci)
  • Size – 1 micron (diameter)
  • Arrangement of cells – Grape-like clusters
  • Motility – Non-motile
  • Flagella – Non-flagellated
  • Spores – Non-sporing
  • Capsule – present in some strains
  • Gram Staining reaction – Gram +ve



CULTURE REQUIREMENTS OF STAPHYLOCOCCUS AUREUS

Special requirements – No special requirements for culture, readily grows on Ordinary culture media.

 Optimum temperature – 10-42°C

⇒ Optimum pH – 7.4-7.6

⇒ Salt requirements – No special requirements but can tolerate 8-10% salt concentration, useful in culturing Staph aureus in the mixture of bacteria. Many human pathogens cannot tolerate high salt concentrations, adding salt to high concentration makes the selective media for staph aureus.

⇒ Oxygen requirements – Staph aureus is Aerobe and Facultative anaerobe.

⇒ Various culture media for Staphylococcus aureus

  • Nutrient Agar medium
  • Blood Agar medium
  • MacConkey Agar medium
  • Mannitol Salt Agar medium
  • Milk agar
  • Liquid medium

⇒ Selective media for Staphylococcus can be prepared by incorporating 8-10% NaCl, LiCl, Tellurite or Polymixin in the NAM or other media makes them selective for the growth of Staph aureus.

CULTURAL CHARACTERISTICS OF STAPHYLOCOCCUS AUREUS

STAPHYLOCOCCUS AUREUS CULTURE ON NEUTRIENT AGAR MEDIUM - STAPH AUREUS COLONY - YELLOW PIGMENT PREODUCTION - STAPH AUREUS

Cultural CharacteristicsNAM (Nutrient Agar MediumMacConkey agar medium Blood Agar MediumMannitol Salt AgarMilk Agar
ShapeCircularCircularCircularCircularCircular
Size2-4 mm2-4 mm1-4 mm2-4 mm3-5 mm
ElevationConvexConvexConvexConvexConvex
SurfaceSmoothSmoothSmoothSmoothSmooth
ColorGolden yellowPinkLight golden yellow, surrounded by clear zone (beta hemolysis).YellowGolden yellow (Pigment production enhanced).
StructureOpaqueOpaqueOpaqueOpaqueOpaque
EmulsifiabilityEasily emulsifiableEasily emulsifiableEasily emulsifiableEasily emulsifiableEasily emulsifiable

In liquid culture media like peptone water and Nutrient broth, uniform turbidity is produced which is further analyzed for the morphology (under the microscope), gram reaction, biochemical tests, and staphylococcus specific tests.

That’s all about the Morphology & Cultural Characteristics of Staphylococcus aureus



SAHIL BATRA

Hi, I'm the Founder and Developer of Paramedics World, a blog truly devoted to Paramedics. I am a Medical Lab Tech, a Web Developer and Bibliophiliac. My greatest hobby is to teach and motivate other peoples to do whatever they wanna do in life.

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