this MacConkey with crystal violet can grow enterococcus
E. coli will not grow on Enterococcus agar, as this medium is selective for Enterococcus species and inhibits the growth of other bacteria. Conversely, Enterococcus can grow on Endo agar, which is designed for the isolation of gram-negative bacteria like E. coli but does not specifically inhibit Enterococcus. However, the growth of Enterococcus on Endo agar may be less pronounced compared to that of E. coli.
MacConkey agar is designed to grow Gram-negative bacteria and also contains crystal violet dye which inhibits the growth of Gram-positive bacteria. Since S. aureus is Gram-positive it should not grow on MacConkey agar. No. MacConkey agar inhibits MOST of the Gram-positive bacteria. There are some Gram-positive bacteria that can tolerate bile-salt are able to grow in MacConkey agar. Enterococcus and some species of Staphylococcus are able to grow in MacConkey. (lack citation though)
Clostridium species do not grow on MacConkey agar because they are anaerobic bacteria that require an oxygen-free environment, while MacConkey agar is designed for the growth of aerobic and facultatively anaerobic Gram-negative bacteria. Additionally, MacConkey agar is selective for lactose fermenters, and Clostridium does not ferment lactose. Therefore, Clostridium cannot be cultured on this medium.
E. coli that grow on MacConkey agar typically exhibit lactose fermentation, causing them to produce pink or red colonies. These colonies may also appear mucoid due to the production of a polysaccharide capsule. Additionally, E. coli on MacConkey agar will typically not grow well under acidic conditions, as the agar contains crystal violet which inhibits the growth of Gram-positive bacteria.
Lactococcus lactis is a bacteria commonly used in the production of dairy products like cheese and yogurt, while Enterococcus faecalis is a bacteria that is often found in the intestines of animals and humans. L. lactis is generally considered safe, whereas E. faecalis can be a pathogen and cause infections in humans, particularly in hospital settings. Additionally, L. lactis is a lactic acid bacterium used in fermentation processes, while E. faecalis is a member of the Enterococcus genus known for its ability to survive in harsh environments.
No, Alcaligenes faecalis will not grow on MacConkey agar. MacConkey agar is selective for gram-negative bacteria that ferment lactose. Alcaligenes faecalis is a gram-negative bacteria that does not ferment lactose, so it will not grow on MacConkey agar.
E. coli will not grow on Enterococcus agar, as this medium is selective for Enterococcus species and inhibits the growth of other bacteria. Conversely, Enterococcus can grow on Endo agar, which is designed for the isolation of gram-negative bacteria like E. coli but does not specifically inhibit Enterococcus. However, the growth of Enterococcus on Endo agar may be less pronounced compared to that of E. coli.
MacConkey agar is designed to grow Gram-negative bacteria and also contains crystal violet dye which inhibits the growth of Gram-positive bacteria. Since S. aureus is Gram-positive it should not grow on MacConkey agar. No. MacConkey agar inhibits MOST of the Gram-positive bacteria. There are some Gram-positive bacteria that can tolerate bile-salt are able to grow in MacConkey agar. Enterococcus and some species of Staphylococcus are able to grow in MacConkey. (lack citation though)
MacConkey agar
Clostridium species do not grow on MacConkey agar because they are anaerobic bacteria that require an oxygen-free environment, while MacConkey agar is designed for the growth of aerobic and facultatively anaerobic Gram-negative bacteria. Additionally, MacConkey agar is selective for lactose fermenters, and Clostridium does not ferment lactose. Therefore, Clostridium cannot be cultured on this medium.
Staphylococcus will not grow on Mac since crystal violet inhibits the growth of Gram positivesfmchinea: Actually some species of staphylococcus grow on MacConkey's plate including Staphylococcus aureus.
Gram-negative bacteria that do not grow on MacConkey agar and Eosin Methylene Blue agar include: Helicobacter pylori Neisseria gonorrhoeae Haemophilus influenzae
E. coli that grow on MacConkey agar typically exhibit lactose fermentation, causing them to produce pink or red colonies. These colonies may also appear mucoid due to the production of a polysaccharide capsule. Additionally, E. coli on MacConkey agar will typically not grow well under acidic conditions, as the agar contains crystal violet which inhibits the growth of Gram-positive bacteria.
You would expect the organism to grow better on nutrient agar because it is a general-purpose medium that supports the growth of a wide range of organisms. MacConkey agar, on the other hand, contains inhibitors that selectively inhibit the growth of Gram-negative bacteria, so the organism may not grow as well on this medium.
Lactococcus lactis is a bacteria commonly used in the production of dairy products like cheese and yogurt, while Enterococcus faecalis is a bacteria that is often found in the intestines of animals and humans. L. lactis is generally considered safe, whereas E. faecalis can be a pathogen and cause infections in humans, particularly in hospital settings. Additionally, L. lactis is a lactic acid bacterium used in fermentation processes, while E. faecalis is a member of the Enterococcus genus known for its ability to survive in harsh environments.
Moraxella is a fastidious organism and may grow on MacConkey agar, but not as well as it would on media specifically designed for its growth, such as blood agar. MacConkey agar is selective for Gram-negative bacteria that ferment lactose, which may not support the growth of Moraxella well as it is usually non-lactose fermenting.
Scanning about the microbiologic community, a few references to Gram pos bacteria growing on MacConkey's showed up. One reports a Gram positive rod of unspecified species (see links). Another article says some forms of Enterococcus and Staphylococcus can grow in spite of the bile salts that make this medium so antagonistic to Gram positives. But just as many articles opine that, if this happens, the medium may not have been properly prepared.