Acetylmethylcarbinol production and the classification of aeromonads associated with ulcerative diseases of ectothermic vertebrates.

Page, L. A. (Biological Research Institute, San Diego, and University of California, Davis). Acetylmethylcarbinol production and the classification of aeromonads associated with ulcerative diseases of ectothermic vertebrates. J. Bacteriol. 84:772-777. 1962.-Quantitative colorimetric tests were made for acetylmethylcarbinol (AMC) production by 14 Aeromonas isolates from ulcerous lesions of snakes, lizards, frogs, and other animals, and by 27 cultures of "identified" aeromonads. The tests revealed that: (i) some strains failed to produce AMC, while the other strains produced AMC in amounts of 5 to > 100 mug/ml of culture; (ii) the reagents employed in the standard method of Barritt failed to detect AMC in concentrations below 35 mug/ml; and (iii) certain strains reported as producing AMC at 23 C and not at 37 C (or vice versa) produced AMC at both temperatures, but at one temperature produced AMC at a level below the sensitivity of the qualitative test. The strains representing the two biotypes could not be distinguished on the basis of their morphology, habitat, pathogenicity for mice or snakes, or serological specificity. Therefore, the Aeromonas classification proposed by Ewing, Hugh, and Johnson, who incorporated the two biotypes into one species, was followed, and the new isolates were designated A. hydrophila.