What is the gram stain of enterobacter aerogenes?

Answer 1

Enterobacter aerogenes is a Gram negative rod-shaped bacterium in the same family as Esherichia coli. It can grow on many of the same selective media as Esherichia coli, including: MacConkey Agar, EMB agar and Lauryl-Tryptose broth. E. aerogenes ferments lactose, producing acid and gas like Esherichia coli and is classified as an example of coliform bacteria. There are several significant differrences between E. aerogenes and E. coli: 1) Most strains of E.coli are able to grow and produce acid from lactose in a medium such as lauryl tryptose broth or brilliant green bile broth at 44.5 degrees C. while most strains of E. aerogenes do not grow well at that temperature, E. aerogenes grows better at temperatures betwee 34 - 40 degrees C. 2) E. aerogenes carries out 2,3-butanediol fermentation and thus give a positive test in the Voges-Proskauer test while E. coli is negative. 3) E. coli is positive in the methyl red test while E. aerogenes is usually, but not always, negative (this is not the best test to rely on). 4) E.coli is positive for the indole test while E. aerogenes is negative, this is a very reliable test. 5) E. aerogenes can grow on Simmon's citrate agar while E. coli does not. You can distinguish between E. aerogenes and bacteria in the Proteus and Salmonella genera by using the hydrogen sulfide test, using either Kligler's iron agar or triple sugar iron agar. Most Proteus and Salmonella strains produce hydrogen sulfide and make a black precipitate but E. aerogenes does not. There are a lot of similarities between Enterobacter aerogenes and Klebsiella pneumonia. The urease test is one of the few tests that distinguishes E. aerogenes from K. pneumonia. Enterobacter aerogenes is a Gram negative rod-shaped bacterium in the same family as Esherichia coli. It can grow on many of the same selective media as Esherichia coli, including: MacConkey Agar, EMB agar and Lauryl-Tryptose broth. E. aerogenes ferments lactose, producing acid and gas like Esherichia coli and is classified as an example of coliform bacteria. There are several significant differrences between E. aerogenes and E. coli: 1) Most strains of E.coli are able to grow and produce acid from lactose in a medium such as lauryl tryptose broth or brilliant green bile broth at 44.5 degrees C. while most strains of E. aerogenes do not grow well at that temperature, E. aerogenes grows better at temperatures between 34 - 40 degrees C. 2) E. aerogenes carries out 2,3-butanediol fermentation and thus give a positive test in the Voges-Proskauer test while E. coli is negative. 3) E. coli is positive in the methyl red test while E. aerogenes is usually, but not always, negative (this is not the best test to rely on). 4) E.coli is positive for the indole test while E. aerogenes is negative, this is a very reliable test. 5) E. aerogenes can grow on Simmon's citrate agar while E. coli does not. You can distinguish between E. aerogenes and bacteria in the Proteus and Salmonella genera by using the hydrogen sulfide test, using either Kligler's iron agar or triple sugar iron agar. Most Proteus and Salmonella strains produce hydrogen sulfide and make a black precipitate but E. aerogenes does not. There are a lot of similarities between Enterobacter aerogenes and Klebsiella pneumonia. The urease test is one of the few tests that distinguishes E. aerogenes from K. pneumonia. Klebsiella is positive for urease production while Enterobacter is negative.

Answer 2

E. aerogenes is a Gram negative bacillus, therefore you will see pink rods. Furthermore, these organisms have no particular arrangement.

Answer 3

citrate test or a sucrose fermentation tube