[Use of the A-2 elective medium for the differentiation of Aeromonas from related microorganisms]

The trial of culture medium A-2, proposed for the identification of Aeromonas on the basis of the nutritional utilization of gelatin as the only source of nitrogen and starch as the source of carbon in view of the limited content of mineral components in the medium, revealed that no other species of the family Vibronaceae grew in this medium, and it could be used in an additional test for the differentiation of vibrios from Aeromonas. A group of strains isolated from human feces, surface water and sewage was found to be incapable of growing in culture medium A-2; these strains, though having a number of characteristics in common with Aeromonas, differed from them in a number of additional tests.