What are the important characteristics of all Staphylococcus?

Characteristics. Staphylococci are Gram-positive, nonspore forming, facultatively anaerobic, nonmotile, catalase-positive or negative, small, spherical bacteria from pairs to, grape-like clusters, from where the name Staphylococcus comes from (staphyle, meaning a bunch of grapes, and kokkos, meaning berry).

What are the physical characteristics of Staphylococcus?

Staphylococci are Gram-positive cocci about 0.5 – 1.0 μm in diameter. They grow in clusters, pairs and occasionally in short chains. The clusters arise because staphylococci divide in two planes.

What culture is Staphylococcus aureus?

Staph. aureus will grow on general culture media such as Blood Agar and chocolated Blood Agar and therefore can be isolated from direct plating of clinical specimens. More specialised media, such as Staph/Strep Selective Medium contain antimicrobials.

What are the cultural characteristics of Staphylococcus aureus?

CULTURAL CHARACTERISTICS They are facultative anaerobes but grow best in aerobic environment at 35ᵒC – 37ᵒC on blood agar and mannitol salt agar as a selective medium. This selective medium is specially used in cases of food poisoning by staphylococcus. S. aureus colonies are about 1-2 mm in size and yellow to golden in color.

How big are Staphylococcus aureus colonies after incubation?

Staphylococcus Aureus produces occasionally white 1-2 mm in diameter colonies or yellow to cream after overnight incubation. Pigment is less clear in young colonies. Some strains are beta haemolytic in the presence of oxygen. Colonies are easily emulsified and slightly raised. Staphylococcus Aureus on blood agar.

What kind of agar does Staph aureus use?

S. Aureus ferments the mannitol and is able to grow on agar contaning 70 – 100 g/l sodium cholride. Mannitol Salt agar also be used for isolating Methicillin Resistant Staph Aureus (MRSA) which contain 75g/l sodium cholorid and 4mg/l methicillin. Tryptic Soy Agar is a growth media for different bacteria.

How are selective media prepared for Staphylococcus aureus?

⇒ 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. Light golden yellow, surrounded by clear zone (beta hemolysis). Golden yellow (Pigment production enhanced).