Phylum Proteobacteria, Class Gammaproteobacteria, Order Aeromonadales, Family Aeromonadaceae, Genus Aeromonas,
Aeromonas encheleia Esteve et al. 1995 emend. Huys et al. 1997.
Strains of Aeromonas eucrenophila subgroup II, the strains of Aeromonas sp. HG11, and ten Aeromonas encheleia-like isolates
were included in Aeromonas encheleia species.
Gram-negative, straight rods. Motile by a polar flagellum.
Colonies develop within 24 hours at 28 ºC on TSA and are not pigmented. Old
cultures (10-15 days) may have light brown pigmented colonies. No brown
water-soluble pigment is produced. Growth occurs on MacConkey agar but not on
TCBS (Thiosulfate - Citrate - Bile salts - Sucrose) agar. Hemolysis on sheep blood
agar is variable (4 of 19 strains were positive). Mesophilic, optimum growth
temperature 28 ºC. No growth at 42 ºC. Can grow in nutrient broth with: 0 and 3%
NaCl, but not in the presence of 6, 8, or 10% NaCl. Can grow in pH 9.0 media.
Isolated from fresh water and fish (eels). One isolate of human origin.
Resistant to vibriostatic agent O/129, amoxicillin, ampicillin, cefetamet, oxacillin, penicillin G, teicoplanin, and vancomycin.
Isolated from healthy European eels. Not pathogenic for mice.
- Geert Huys, Peter Kämpfer, Martin Altwegg, Renata Coopman, Paul Janssen, Monique Gillis, and Karel Kersters. Inclusion of
Aeromonas DNA Hybridization Group 11 in Aeromonas encheleia and Extended Descriptions of the Species Aeromonas
eucrenophila and A. encheleia. Int J Syst Bacteriol October 1997 47:1157-1164.
- 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.
- Consuelo Esteve, M. Carmen Gutiérrez, and Antonio Ventosa. Aeromonas encheleia sp. nov., Isolated from European Eels. Int J
Syst Bacteriol July 1995 45:462-466.
Positive results for catalase, oxidase, nitrates reduction, indole production, ONPG,
acetate utilization, growth in KCN medium, DN-ase, esculin hydrolysis, lipase (corn oil), acid production from: D-glucose (variable gas
production), glycerol, D-galactose, maltose, D-mannitol & D-trehalose.
Negative results for urea hydrolysis, citrate utilization, malonate utilization, Voges-Proskauer test, lysine decarboxylase, elastase,
chitin hydrolysis, acid production from: adonitol, D-amygdalin, D-arabitol, L-arabinose, cellobiose, dulcitol, erythritol, inositol, lactose,
alpha-methyl-D-glucoside, melibiose, D-raffinose, D-sorbitol & D-xylose.
Variable results for gelatin hydrolysis, arginine, dihydrolase, ornithine decarboxylase, H2S production from cysteine thiosulphate,
acid production from: L-rhamnose, salicin & sucrose.
(c) Costin Stoica