Will Serratia marcescens grow in mannitol salt agar?

Most non-pathogenic staphylococci will not ferment mannitol. The Staphylococcus aureus ferments mannitol and turns the medium yellow. The Serratia marcescens does not grow because of the high salt content.

What bacteria Cannot Grow on Mannitol Salt Agar?

Gram-negative bacteria like E. coli and P. aeriginosa are not tolerant to salt (not halophilic) and will not grow colonies on MSA (see quadrants II and IV). Pathogenic gram-positive Staphylococcus aureus salt-tolerant (halophilic) and will produce colonies on MSA.

Does S marcescens grow on MSA?

S. marcescens, which produces a red pigment, was grown on nutrient agar, a general purpose medium that supports the growth of a variety of bacteria. Mannitol Salt Agar (MSA) supports the growth of Staphylococcus aureus, a gram-positive bacterium.

Can Serratia marcescens ferment mannitol?

Serratia marcescens was able to metabolize mannitol to produce acid, but gas was not produced. Glucose – Positive for the fermentation of glucose to produce acid, but negative for the production of gas.

How do you grow Serratia marcescens?

Serratia, like other Enterobacteriaceae, grow well on ordinary media under anaerobic and aerobic conditions. They grow well on synthetic media using various compounds as a single carbon source. Optimum growth of all strains of Serratia has been observed at pH 9 and at temperatures from 20–37°C.

Mannitol Salt Agar (MSA) | Results

What can grow on a MSA plate?

This type of medium is both selective and differential. The MSA will select for organisms such as Staphylococcus species which can live in areas of high salt concentration (plate on the left in the picture below).

Which bacterium is positive on MSA test?

In clinical samples, mannitol positive isolates are suggestive of Staphylococcus aureus and should be further tested. A non-fermenting bacteria that resists the high salt concentration results in a red to pink area due to the degradation of the peptone.

What does pink growth on an MSA plate indicate?

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.

Does Staphylococcus epidermidis Grow on mannitol salt agar?

Staphylococcus epidermidis grows on MSA, but does not ferment mannitol (media remains light pink in color, colonies are colorless). Fig. 8 Staphylococcus epidermidis on Mannitol Salt Agar.

Can Streptococcus grow on mannitol salt agar?

Mannitol Salt Agar (MSA)

Staphylococcus species, which commonly inhabit human skin, can grow on this high salt concentration (left plate in picture below). This is in contrast to Streptococcus species, whose growth is selected against by this high salt agar (plate on the right in the picture below).

Does Staphylococcus Saprophyticus Grow on mannitol salt agar?

Members of the genus Staphylococcus can tolerate high salt concentration (7.5%) and grow on mannitol salt agar.

What does mannitol salt agar select?

Mannitol Salt Agar (MSA) is a selective and differential medium. The high concentration of salt (7.5%) selects for members of the genus Staphylococcus, since they can tolerate high saline levels. Organisms from other genera may grow, but they typically grow very weakly.

What does growth on a mannitol salt agar plate mean?

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.

Why is mannitol salt agar used?

Mannitol Salt Agar is used as a selective media for the isolation of pathogenic Staphylococci. It is recommended for the detection and enumeration of coagulase-positive Staphylococci in milk, food and other specimens. It is recommended in U.S.P. for use in the performance of microbial limit tests.

Is mannitol salt agar selective or differential?

Mannitol Salt Agar (MSA) is both selective and differential. It contains 7.5% sodium chloride which selects for organisms that are halotolerant. It also contains the carbohydrate mannitol, and a pH indicator, phenol red, which allow distinction between organisms which can ferment mannitol and those that can not.

Does Klebsiella pneumoniae grow on MSA?

Klebsiella spp. does grow in all sectors except on mannitol salt agar and note that no colour change has occured in the PGUA agar, which it would have done if E. coli is growing on this medium.

Where can Serratia grow?

Where Is Serratia Marcescens Found? Serratia marcescens is found in fresh and stagnant water or saline, in the soil, and in plants, insects, and animals including the human species.

At what temperature does Serratia marcescens grow?

Perhaps it is noteworthy that the optimal growth range for Serratia marcescens is 25-37C, and it is above this temperature range that pigment production ceases. It is possible that the loss of pigment is associated with mild temperature stress.

Where is Serratia marcescens normally found?

Serratia marcescens (S. marcescens) is a gram-negative bacillus that occurs naturally in soil and water and produces a red pigment at room temperature. It is associated with urinary and respiratory infections, endocarditis, osteomyelitis, septicemia, wound infections, eye infections, and meningitis.

How can you differentiate Staphylococcus Staphylococcus Saprophyticus from Staphylococcus epidermidis?

The main difference between Staphylococcus epidermidis and Staphylococcus saprophyticus is that Staphylococcus epidermidis is sensitive to novobiocin whereas Staphylococcus saprophyticus is resistant to novobiocin. In addition, S. epidermidis forms bright-white, creamy colonies while S.

Does micrococcus grow on MSA?

Mannitol Salt Agar can be used to culture Micrococcus spp as it is selective for certain Gram- positive microorganisms. However, it will also allow growth of Staphylococcus so further identification work must be conducted to form a strong identification of Micrococcus presence. Infection: M.

Does Bacillus grow on MSA?

The large colonies at the center of the plate are Bacillus cereus. Although these organisms grow well on nutrient agar, they are not halophiles so will not grow on mannitol salt agar. These organisms are Gram-positive, so their growth is effectively inhibited by the chemicals in Tergitol-7 and MacConkey's agar.

How can you distinguish between Staphylococcus and Streptococcus?

Streptococci are Gram-positive cocci that grow in pairs or chains. They are readily distinguished from staphylococci by their Gram-stain appearance and by a negative catalase test. More than 30 species have been identified. The classification of streptococci is complex and is based on a combination of features.

How do you differentiate between Staphylococcus and Streptococcus?

Staphylococci and Streptococci are grouped as Gram-positive cocci. Staphylococci form clumps, whereas Streptococci grow in chains. They can be discriminated by catalase test because Staphylococci have the capability to produce catalase [2].