Streptococcus Selective Agar is a selective medium recommended for use in the primary isolation of groups A Streptococcus species (S. pyogenes) from oral culture and respiratory specimens.

What kind of media is used for Streptococcus species?

Most streptococci are facultative anaerobes, and some are obligate (strict) anaerobes. Most require enriched media (blood agar).

Which medium is used to select for faecal streptococci?

Faecal streptococci grow in or on a medium containing sodium azide, at a temperature of 37-44 °C.

Is blood agar a selective or differential media for group A streptococcus identification?

Blood agar is differential media because 3 different types of hemolysis, or lysing of red blood cells, can be seen on this plate.

Which of the following blood agar is used as selective media for Streptococcus pyogenes?

Gentian violet blood agar was selective for Str. pyogenes in presence of Staph. aureus only;P.N.F. medium was selective for the streptococci in mixtures with staphylococci and with Gram-negative bacilli.

Microbiology - Streptococcus species

44 related questions found

Can Streptococcus grow on MacConkey Agar?

Hence, it does not grow on MacConkey agar (MA) due to the absence of blood as well as due to the presence of high concentration of bile in the medium which is inhibitory to the growth of S.

Is Streptococcus pyogenes aerobic or anaerobic?

Streptococcus pyogenes is a Gram-positive, spherical, and facultative anaerobic bacterium.

Why is blood agar not a selective media?

Blood agar is an enriched medium that provides an extra rich nutrient environment for microbes. Therefore, BAP is not a selective growth medium, since it supports the growth of a wide range of organisms.

What is the selective media for Staphylococcus aureus?

Mannitol salt agar containing 7.5% NaCl (most media contain 0.5% NaCl) has been used as a selective medium, as S. aureus is capable of fermenting mannitol.

What does no group A streptococcus isolated mean?

Counter to guidelines, children with pharyngitis in whom non–group A strep is isolated commonly receive antibiotics. Non–group A streptococcus (NGAS) is detected in close to 12% of throat cultures performed for pharyngitis in school-age children. The detected bacteria likely reflect colonization rather than infection.

Can media be both selective differential?

Selective and differential media can be combined and play an important role in the identification of bacteria by biochemical methods. Another commonly used medium that is both selective and differential is eosin-methylene blue (EMB) agar. ... Therefore, EMB is selective for gram-negatives.

What are examples of selective media?

Examples of selective media:

• Eosin methylene blue contains dyes that are toxic for Gram-positive bacteria. ...
• YM (yeast extract, malt extract agar) has a low pH, deterring bacterial growth.
• MacConkey agar is for Gram-negative bacteria.
• Hektoen enteric agar is selective for Gram-negative bacteria.

What is a media type that is selective for gram-positive organisms?

Mannitol salt agar (MSA) which is selective for Gram-positive bacteria and differential for mannitol.

Is Streptococcus prokaryotic or eukaryotic?

Streptococcus pyogenes, the bacterium that causes strep throat, is an example of prokaryotes. Yeast, the organism that makes bread rise and beer ferment, is an example of unicellular eukaryotes. Humans, of course, are an example of multicellular eukaryotes.

Which of the following is both a selective and differential media?

This medium is both selective and differential. The selective ingredients are the bile salts and the dye, crystal violet which inhibit the growth of Gram-positive bacteria.

Is Streptococcus pyogenes heterotrophic or autotrophic?

"Lunch Time!" Streptococcus mutans is a heterotrophic organism. This means that Streptococcus mutans cannot synthesize reduced organic compounds from inorganic sources and that it must obtain them by eating other organisms (Freeman).

What are the different selective media used for isolating Staphylococcus species?

Two selective media (mannitol salt agar and Staphy- lococcus medium 110 agar) used for the isolation and enumeration of staphylococci depend on salt to inhibit non-staphylococci. Baird-Parker agar achieves its selectiv- ity through the addition of potassium tellurite and lithium chloride.

Which media selects for Staphylococcus?

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.

What type of plate would you use to select for Staphylococcus?

Mannitol Salt Agar (MSA) is used as a selective and differential medium for the isolation and identification of Staphylococcus aureus from clinical and non-clinical specimens.

Can blood agar also be a selective media?

Used for the isolation of Streptococcus & Moraxella species based on ability to break down red blood cells. In Blood Agar, blood is added to media after autoclaving (heat sterilization). This medium can be made selective by the addition of antibiotics.

Is the blood agar media selective and/or differential explain your answer?

A selective media is composed of specific ingredients to inhibit the growth of certain species of microbes in a mixed culture while allowing others to grow. ... Blood agar is a differential medium that distinguishes bacterial species by their ability to break down red blood cells.

Is blood agar selective or differential quizlet?

Blood agar is Differential and enrich. Beta-hemolysis is complete hemolysis. It is characterized by a clear (transparent) zone surrounding the colonies.

Are streptococci motile?

Streptococci are non-motile, microaerophilic, Grampositive spherical bacteria (cocci). They often occur as chains or pairs and are facultative or strict anaerobes. Streptococci give a negative catalase test, while staphylococci are catalase-positive.

Is Streptococcus pneumoniae aerobic or anaerobic?

Streptococcus pneumoniae are lancet-shaped, gram-positive, facultative anaerobic bacteria with 100 known serotypes. Most S. pneumoniae serotypes can cause disease, but only a minority of serotypes produce the majority of pneumococcal infections.

Does Streptococcus pyogenes grow on blood agar?

To detect streptococci in clinical samples (and especially S. pyogenes), the material is most often cultured on blood agar plates, which facilitates an easy preliminary screen for β-hemolytic colonies.