Aeromonas salmonicida

From MicrobeWiki, the student-edited microbiology resource

A Microbial Biorealm page on the genus Aeromonas salmonicida



Classification

Higher order taxa

Bacteria; Proteobacteria; Gammaproteobacteria; Aeromonadales; Aeromonadaceae; Aeromonas

Genus species

Aeromonas salmonicida

Description and significance

Aeromonas salmonicida is a gram-negative bacterium. Most strands of the bacterium are non-motile. The bacterium’s optimal growth temperature is between 22 and 25°C. The maximum temperature that it can grow at is 34.5°C. After about a 24 hour growth period the colonies are about the size of a pin point. The colonies also have a brown pigmented color that appears after it has been growing for 48-72 hours. It is negative for the indole formation test, Voges-Proskauer test, citrate utilization test, coagulase test, starch hydrolysis, casein hydrolysis, triglyceride hydrolysis, phospholipid hydrolysis, hydrogen sulfide production, citrate utilization, and the phenylalanine test. It is positive for the oxidase test, lysine decarboxlase test, methyl red test, gelatin hydrolysis test, and catalase test.

Aeromonas salmonicida colonies on TSA exhibiting diffusable brown pigment on the left half; on the right half is the nonpigmented Enterobacter aerogenes.[1]

Plate provided by J. Cox, A. Beuler, G. Cervenka and K. Grospe and image taken by M. Glogowski

Genome structure

Cell structure and metabolism

Aeromonas salmonicida is bacillus in shape. The short rods have rounded ends which allow it to be easily confused as a coccus. The colony size of Aeromonas salmonicida is between 1-2nm. Aeromonas salmonicida is a facultative anaerobic which means that it is capable of making ATP by aerobic respiration if oxygen is present but is also capable of switching to fermentation when oxygen is not present. It does not have fermentation of sucrose or lactose but it does of glucose. The glucose fermentation also created gas.

Ecology

Pathology

Aeromonas salmonicida is the bacterium that causes the disease furunculosis in marine and freshwater fish. The bacterium is pathogenic for fish. The symptoms the fish show are external and internal hemorrhaging, swelling of the vents and kidneys, boils, ulcers, liquefaction, and gastroenteritis. Furunculosis is commonly known as tail rot in fish and is common in gold and koi fish. Infected fish with open sores are able to spread the disease to other fish.

References

Bergey,David Hendricks,.Bergey's Manual of Systematic Bacteriology. Vol. 2, The Proteobacteria. Part B,The Gammaproteobacteria.Williams & Wilkins, 1984.


Created by students of M Glogowski