Can Enterobacter aerogenes grow on MacConkey agar?
Using the enzymes beta-galactosidase and beta-galactoside permeases, the most frequently encountered species of Enterobacter strains activate the pH indicator (neutral red) included in MacConkey agar, giving a pink or red stain to the growing colonies.
What color is Enterobacter aerogenes on MacConkey agar?
pink color
Quadrant 1: Growth on the plate indicates the organism, Enterobacter aerogenes, is not inhibited by bile salts and crystal violet and is a gram-negative bacterium. The pink color of the bacterial growth indicates E. aerogenes is able to ferment lactose.
Is Enterobacter aerogenes a lactose fermenter?
These bacteria ferment lactose, are motile, and form mucoid colonies. Enterobacter strains commonly arise from the endogenous intestinal flora of hospitalized patients but can occur in common source outbreaks or are spread from patient to patient.
What media does Enterobacter aerogenes grow on?
Environments known to contain Enterobacter Enterobacter can be found on human skin, plants, soil, water, sewage, intestinal tracts of animals, including humans, dairy products; and clinical specimens such as feces, urine, blood, sputum, and wound exudates.
Does Providencia Stuartii grow on MacConkey agar?
stuartii is that it is motile via flagella, non-sporulating, non-lactose fermenting, catalase positive and oxidase negative. It can also grow in anaerobic conditions and on Simmon’s Citrate Agar….
| Providencia stuartii | |
|---|---|
| Scientific classification | |
| Family: | Enterobacteriaceae |
| Genus: | Providencia |
| Species: | P. stuartii |
Does Staphylococcus aureus grow on MacConkey agar?
MacConkey agar selects for organisms like Escherichia coli (Gram negative bacilli) while inhibiting the growth of organisms like Staphylococcus aureus (Gram positive cocci).
Does Shigella grow on MacConkey agar?
Shigella grows as non-lactose-fermenting colonies on MacConkey agar, although a more selective agar is used for the isolation of Shigella from feces, such as deoxycholate citrate agar and xylose lysine deoxycholate agar.
What does Klebsiella aerogenes look like?
Klebsiella aerogenes, previously known as Enterobacter aerogenes, is a Gram-negative, oxidase negative, catalase positive, citrate positive, indole negative, rod-shaped bacterium. The bacterium is approximately 1-3 microns in length, and is capable of motility via peritrichous flagella.
Where is Enterobacter aerogenes found?
aerogenes is typically found in the human gastrointestinal tract and does not generally cause disease in healthy individuals. It has been found to live in various wastes, hygienic chemicals, and soil.
Does Providencia Rettgeri grow on MacConkey Agar?
rettgeri) is a motile, gram-negative rod shaped organism and a member of the Enterobacteriaceae family. It is capable of growth on MacConkey agar, capable of catalyzing the dissociation of urea into ammonia and carbon dioxide, capable of deaminating phenylalanine, and capable of producing gas from glucose fermentation.
What bacteria can be found on MacConkey agar?
The very essence of MacConkey agar is to differentiate between lactose fermenting and non-lactose fermenting gram-negative bacteria. Lactose fermenting – Enterobacter aerogenes, Escherichia coli, and Klebsiella. Non-lactose fermenting – Salmonella typhimurium, Proteus species, Shigella, Pseudomonas aeruginosa, and Yersinia. (1, 3, 6, and 8)
Who is the author of Enterobacteriaceae on MacConkey agar?
Author: Susan L Fraser, MD; Chief Editor: Michael Stuart Bronze, MD more… MacConkey agar is a lactose-containing medium that is selective for nonfastidious gram-negative bacilli such as Enterobacteriaceae.
What is the color of Enterobacter aerogenes?
Organisms which ferment lactose produce acid end-products which react with the pH indicator neutral red, and produce a pink color. Quadrant 1: Growth on the plate indicates the organism, Enterobacter aerogenes, is not inhibited by bile salts and crystal violet and is a gram-negative bacterium.
Why is MacConkey agar plate sensitive to carbon dioxide?
The incubation of MacConkey agar plate makes it susceptible to an increase in carbon dioxide which can significantly affect the growth/reduction of some strains of Gram-negative bacilli. (2, 6, and 9) Why is MacConkey agar selective as well as a differential? The MacConkey medium is identified as a selective and a differential medium.