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What is mannitol salt test for and whats a positive test result?
Wiki User
∙ 15y ago
Mannitol Salts agar is a selective and differential media used to identify Staphylococcus sp. The media is selective due to the high salt concentration which prevents all but halophiles from growing. The media is differential due to the presence of mannitol and the indicator Phenol Red. Staphylococcus aureus can ferment mannitol and produce lactic acid as a result. The media contains an indicator called Phenol Red which turns yellow in low pH environments. This results in a yellow halo around the S.aureus colonies. Staphylococcus epidermidis cannot ferment mannitol and so the colour of the media around these colonies does not change. Certain vibro species and other halophiles may grow on these plates some of these appear pink and some may be able to ferment mannitol leading to false positives. S.epidermidis is a normal commensal organism and grows on the skin. S.aureus is a potential pathogen, antibiotic strains exist and can be hospital accquired infections. Search for "MRSA" for more information.
Wiki User
∙ 15y ago
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What reaction does the enzyme involved in Mannitol-salt agar test mediate?
Mannitol salt agar is selective for gram positive bacteria, and differential for mannitol fermenters. Phenol red is the indicator containing the enzyme mannitol.
Does bacillus subtilis ferment acid from mannitol salt agar?
Bacillus subtilis typically does not ferment acid from mannitol salt agar as it lacks the enzymes needed for fermentation. Mannitol salt agar is mostly used to differentiate Staphylococcus species, which are capable of fermenting mannitol.
Does E. faecalis test positive for MSA agar test?
E. faecalis typically does not ferment mannitol, so it does not grow well on mannitol salt agar (MSA) and would not test positive on this medium. MSA is selective for organisms that can ferment mannitol, such as Staphylococcus species.
Can enterobacter cloacae grow on mannitol salt agar?
Yes, Enterobacter cloacae typically cannot grow on mannitol salt agar because it does not ferment mannitol. Mannitol salt agar is selective for salt-tolerant Staphylococci species that can ferment mannitol, producing acid and turning the agar yellow.
What organisms do not grow on msa and mannitol?
Organisms that do not grow on Mannitol Salt Agar (MSA) are non-halophilic bacteria that are unable to tolerate high salt concentrations. Mannitol-fermenting bacteria are organisms that can ferment mannitol and grow on MSA, while non-fermenting bacteria will not grow.
What reaction does the enzyme involved in Mannitol-salt agar test mediate?
Mannitol salt agar is selective for gram positive bacteria, and differential for mannitol fermenters. Phenol red is the indicator containing the enzyme mannitol.
Does bacillus subtilis ferment acid from mannitol salt agar?
Bacillus subtilis typically does not ferment acid from mannitol salt agar as it lacks the enzymes needed for fermentation. Mannitol salt agar is mostly used to differentiate Staphylococcus species, which are capable of fermenting mannitol.
Does E. faecalis test positive for MSA agar test?
E. faecalis typically does not ferment mannitol, so it does not grow well on mannitol salt agar (MSA) and would not test positive on this medium. MSA is selective for organisms that can ferment mannitol, such as Staphylococcus species.
Can enterobacter cloacae grow on mannitol salt agar?
Yes, Enterobacter cloacae typically cannot grow on mannitol salt agar because it does not ferment mannitol. Mannitol salt agar is selective for salt-tolerant Staphylococci species that can ferment mannitol, producing acid and turning the agar yellow.
HOW do mannitol salt hook up to glycolysis?
Mannitol is not a substrate for glycolisis
What ingredient makes mannitol salt selective?
the salt content
Why can mannitol salt agar and EMB agar be described as both selective and differential media?
Mannitol salt agar is selective because the high salt concentration inhibits the growth of most bacteria except salt-tolerant Staphylococci species. It is differential because it contains mannitol and a pH indicator that changes color if mannitol is fermented. EMB agar is selective because it inhibits the growth of Gram-positive bacteria, and it is differential because it contains lactose and eosin/methylene blue dyes that differentiate between lactose fermenters and non-fermenters based on color change.
Why does gram-positive bacteria grow in mannitol agar?
Gram-positive bacteria can grow on mannitol agar because they have the ability to ferment mannitol sugar present in the agar, producing acids as byproducts. This lowers the pH of the agar, causing a color change in the pH indicator (phenol red) from red to yellow, which is a characteristic reaction for gram-positive bacteria.
Which ingredient in mannitol salt agar supplies carbon?
mannitol is a type of sugar, so it supplies the carbon in the MSA medium
What organisms do not grow on msa and mannitol?
Organisms that do not grow on Mannitol Salt Agar (MSA) are non-halophilic bacteria that are unable to tolerate high salt concentrations. Mannitol-fermenting bacteria are organisms that can ferment mannitol and grow on MSA, while non-fermenting bacteria will not grow.
Can B subtilis grow on MSA?
No, Bacillus subtilis cannot grow on Mannitol Salt Agar (MSA) as it cannot ferment mannitol and does not tolerate the high salt concentration in MSA. MSA is selective for Staphylococcus species that can ferment mannitol.
Can salmonella typhimurium grow on mannitol salt agar?
No, Salmonella Typhimurium cannot grow on Mannitol Salt Agar because it is a selective and differential media primarily used for isolating and differentiating Staphylococcus species based on their ability to ferment mannitol. Salmonella Typhimurium is not a mannitol fermenter, so it will not grow on this agar.
