Staphylococcus species Flashcards
The catalase test should be performed from a medium that does not contain blood because red cells themselves may
produce
weakly positive catalase reaction
Reagent for Catalase test
3% hydrogen peroxide.
(+) result for Catalase test
Rapid and sustained appearance of bubbles or effervescence
(-) result for Catalase test
No bubbles produced or a few tiny bubbles forming after 20-30 seconds.
(+) control for Catalase test
Staphylococcus aureus
(-) control for Catalase test
Streptococcus species
Reagent for Slide Coagulase test
sterile distilled water or physiologic saline; rabbit plasma with EDTA
(+) result for Slide Coagulase test
Formation of white precipitate or clumping within 10-15 seconds of mixing the plasma with the bacterial suspension; Saline control remains smooth and milky
(-) result for Slide Coagulase test
No clumping in either drop observed after 2 minutes
Clumping in both drops indicates that the organisms is unsuitable for slide coagulase test
autoagglutinate
Reagent for Tube Coagulase test
0.5 ml of plasma rabbit plasma with EDTA
(+) result for Tube Coagulase test
Clotting of plasma (any degree)
(-) result for Tube Coagulase test
No clot
(+) control for Tube Coagulase test
Staphylococcus aureus
(-) control for Tube Coagulase test
Coagulase-negaTve staphylococci (CoNS)
Staphylococcus epidermidis
Staphylococcus saprophyticus
