function of eosin methylene blue agar (EMB)
Eosin methylene blue (EMB) agar is selective for gram-negative bacteria, especially those that can ferment lactose. Common bacteria that grow on EMB agar include Escherichia coli and Enterobacter aerogenes. These bacteria are differentiated by their ability to ferment lactose, producing colonies that are metallic green or dark purple on EMB agar.
Pseudomonas aeruginosa can grow on Emb agar, as it is a selective and differential growth medium commonly used to isolate and differentiate members of the Enterobacteriaceae family, including P. aeruginosa. Its growth on Emb agar will exhibit the characteristic green metallic sheen due to its ability to produce pyocyanin pigment.
The conclusion drawn if no growth appeared on MacConkey agar and EMB agar after inoculation of the media and an incubation period could be the bacteria used was possibly a Gram positive non-enteric sample.
Staphylococcus bacteria typically do not grow well on Eosin Methylene Blue (EMB) agar. EMB agar is selective for gram-negative bacteria, particularly Enterobacteriaceae, and contains dyes that inhibit the growth of gram-positive bacteria like Staphylococcus.
Bacillus bacteria typically do not grow well on Eosin Methylene Blue (EMB) agar because they are gram-positive bacteria. EMB agar is designed to inhibit the growth of gram-positive bacteria and isolate gram-negative bacteria, such as Escherichia coli.
Mycobacterium phlei is a non-fastidious organism that is commonly found in soil and water. It is not commonly grown on Eosin Methylene Blue (EMB) agar, as EMB agar is more selective for gram-negative enteric bacteria. Instead, Mycobacterium phlei is typically cultured on media specifically designed for mycobacteria, such as Middlebrook agar or Lowenstein-Jensen agar.
Eosin methylene blue (EMB) agar is selective for gram-negative bacteria, especially those that can ferment lactose. Common bacteria that grow on EMB agar include Escherichia coli and Enterobacter aerogenes. These bacteria are differentiated by their ability to ferment lactose, producing colonies that are metallic green or dark purple on EMB agar.
EMB Agar
Most gram positive bacteria do not grow on MacConkey agar or Eosin Methylene Blue (EMB) agar, as these are selective media designed to inhibit the growth of gram positive organisms. So, typically, you would not expect a gram positive bacteria to grow on these media.
The conclusion drawn if no growth appeared on MacConkey agar and EMB agar after inoculation of the media and an incubation period could be the bacteria used was possibly a Gram positive non-enteric sample.
The peptones in EMB agar provide nitrogen for bacterial growth, while the lactose is a source of carbon. These ingredients support the growth of certain coliform bacteria, which ferment lactose to produce characteristic color changes on the agar.
Pseudomonas aeruginosa can grow on Emb agar, as it is a selective and differential growth medium commonly used to isolate and differentiate members of the Enterobacteriaceae family, including P. aeruginosa. Its growth on Emb agar will exhibit the characteristic green metallic sheen due to its ability to produce pyocyanin pigment.
The conclusion drawn if no growth appeared on MacConkey agar and EMB agar after inoculation of the media and an incubation period could be the bacteria used was possibly a Gram positive non-enteric sample.
Staphylococcus bacteria typically do not grow well on Eosin Methylene Blue (EMB) agar. EMB agar is selective for gram-negative bacteria, particularly Enterobacteriaceae, and contains dyes that inhibit the growth of gram-positive bacteria like Staphylococcus.
On nutrient agar, Yersinia appears as smooth, opaque colonies with a pale yellowish color. On EMB agar, colonies may show greenish metallic sheen due to lactose fermentation. On MacConkey agar, Yersinia typically forms colorless to pale pink colonies due to its inability to ferment lactose.
EMB agar is a complex undefined medium because it contains multiple components such as peptone, lactose, agar, and eosin Y and methylene blue dyes that promote the growth of a wide variety of bacteria while inhibiting the growth of certain Gram-positive bacteria.
Bacillus bacteria typically do not grow well on Eosin Methylene Blue (EMB) agar because they are gram-positive bacteria. EMB agar is designed to inhibit the growth of gram-positive bacteria and isolate gram-negative bacteria, such as Escherichia coli.