Saturday, April 24, 2010

MICROBIOLOGY BACTERIA QUESTION???? What bacteria is this??

What bacteria is this???


Gram negative


Methyl Red: Negative


Voges-Proskauer: Negative


Hydrogen Sulfide Production (Peptone Iron): Negative


Gelatin Hydrolysis: Positive


Glucose Utilization: Positive


OF-Glucose: Oxidizer


Starch Hydrolysis: Negative


Motility: Positive


Special Feature: Green-Blue Color in Culture

MICROBIOLOGY BACTERIA QUESTION???? What bacteria is this??
Pseudomonas aeruginosa. The green-blue color is caused by two pigments, fluorescein and pyocyanin, that are produced. It is Gram negative, motile by a polar flagellum, and does utilize glucose, but by respiration rather than by fermentation, which explains the negative results for both the methyl red and the Voges-Proskauer tests. If you grow it on blood agar in pure culture, and sniff the colonies (don't touch them!), you should notice an odor which smells like corn tortillas. I always used that odor to help me in my identification of this pathogen.


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