Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Proteobacteria, Class Gammaproteobacteria, Order Aeromonadales, Family Aeromonadaceae, Genus Aeromonas,
Aeromonas media Allen et al. 1983.
Gram-negative, rod-shaped cells approximately 1-2 µm with rounded ends. Motility is
variable (can be expressed under certain laboratory conditions using appropriate
media, temperature, and incubation periods).
Colonies on TSA are creamy, shiny, smooth, round, raised, entire, and 2 mm in
diameter after incubation for 2 days at 22 ºC. A brown water-soluble pigment is
produced. Uniform turbidity is produced in peptone broth. Facultatively anaerobic.
Beta-hemolysis on 5% sheep blood agar is variable. Growth occurs at temperatures
between 4 and 37 ºC, and not at 42 ºC. Can grow in the presence of 0-3% NaCl.
Grows on CLED (Cysteine-lactose electrolyte-deficient) agar, MacConkey agar, but
not on TCBS (Thiosulfate - Citrate - Bile salt - Sucrose) agar.
Strains isolated from fishponds and other aquatic sources. Resistant to vibriostatic agent O/129 (150 µg).
Undetermined; but association with human diarrheal disease has been reported.
- Allen, D.A., B. Austin and R.R. Colwell. 1983. Aeromonas media, new species isolated from river water. Int. J. Syst. Bacteriol. 33:
599–604.
- Amy Martin-Carnahan and Samuel W. Joseph 2004. Order XII. Aeromonadales ord. nov. In: Bergey’s Manual of Systematic
Bacteriology, Second edition,Vol two, part B, George M. Garrity (Editor-in-Chief), pp. 556-587.
Positive results for catalase, oxidase, nitrates reduction, indole production, methyl red test, ONPG, acid production from: L-arabinose,
cellobiose, maltose, D-mannitol, mannose, sucrose and D-trehalose.
Negative results for urea hydrolysis, malonate utilization, mucate utilization, Voges-Proskauer test, lysine decarboxylase, ornithine
decarboxylase, H2S production from cysteine thiosulphate, elastase, acid production from: adonitol, D-amygdalin, D-arabitol, dulcitol,
erythritol, alpha-methyl-D-glucoside, inositol, melibiose, D-raffinose, L-rhamnose, D-sorbitol and D-xylose.
Variable results for citrate utilization, acetate utilization, growth in KCN medium, gelatin hydrolysis, arginine, dihydrolase, DN-ase,
lipase (corn oil), esculin hydrolysis, acid production from: glycerol, lactose and salicin.
(c) Costin Stoica