Application of isoenzymatic typing to the identification of nonaxenic strains of Naegleria (Protozoa, Rhizopoda).

Isoenzymatic typing of the different species of Naegleria was studied by comparing isoelectric focusing on axenic and nonaxenic strains using the most discriminating enzymes: lactate dehydrogenase (LDH), malic enzyme (ME), beta-hydroxybutyrate dehydrogenase (beta-HBDH), superoxide dismutase (SOD), and acid phosphatase (AP). The results show that bacteria in nonaxenic cultures have no influence on the interpretation of zymograms. The specificity of the enzymatic patterns of each strain is maintained in all of these enzymatic systems except LDH. With SOD, the existence of a supplementary isoenzyme among all of the nonaxenic strains is probably linked to an enzymatic induction phenomenon.