Is Staphylococcus aureus mannitol positive?
Michael Henderson
Published Feb 14, 2026
Is Staphylococcus aureus mannitol positive?
Most non-pathogenic staphylococci will not ferment mannitol. The Staphylococcus aureus ferments mannitol and turns the medium yellow.
How does MSA identify Staphylococcus aureus?
Staphylococcus aureus produces yellow colonies with yellow zones, whereas other coagulase-negative staphylococci produce small pink or red colonies with no colour change to the medium. If an organism can ferment mannitol, an acidic byproduct is formed that causes the phenol red in the agar to turn yellow.
What does a positive mannitol test mean?
A positive test consists of a color change from red to yellow, indicating a pH change to acidic.
Is Staphylococcus aureus lactose positive?
aureus isolates showed positive results in gelatin, urea and galactose hydrolysis test, 50% isolates were positive in starch hydrolysis test, 35% in protein hydrolysis test, 100% isolates in lactose fermenting test, but no isolate was positive in sucrose fermenting test.
What is the DNase test?
The deoxyribonuclease (DNase) test detects the degradation of DNA by bacterial species that produce DNase. The DNase test may be performed on plate media and is available in some commercial tests, e.g., QuadFERM+.
What does MSA plate test for?
Mannitol Salt Agar (MSA) is used to determine if the bacteria is halophilic (salt loving) and if the bacteria can ferment mannitol. If the bacteria is able to grow then it is a halophilic bacteria, due to it’s ability to grow in a high salt environment.
Is Staphylococcus aureus indole positive or negative?
Biochemical Test and Identification of Staphylococcus aureus
| Basic Characteristics | Properties (Staphylococcus aureus) |
|---|---|
| Indole | Negative (-ve) |
| Motility | Negative (-ve) |
| MR (Methyl Red) | Positive (+ve) |
| Nitrate Reduction | Positive (+ve) |
Is Staphylococcus aureus Gram positive or negative?
Staphylococcus aureus is a gram-positive bacteria that cause a wide variety of clinical diseases. Infections caused by this pathogen are common both in community-acquired and hospital-acquired settings.
What does a positive MSA plate look like for Staphylococcus aureus?
Results. Yellow colonies with yellow zones. Colorless or Red colonies with red zones. No growth to trace growth.
