Evaluation of the Indirect Fluorescent-Antibody Technique for Identification of Naegleria Species

The indirect fluorescent-antibody technique was used to assess a rapid method for identification of amoebae belonging to the genusNaegleria . Thirty-eightNaegleria and eight other limax amoeba strains were examined by using oneN. gruberi and twoN. fowleri antisera. All pathogenicNaegleriae , most of which originated from fatal cases of primary amoebic meningo-encephalitis, were identified as belonging to thefowleri species. Most of theN. gruberi strains showed irregular fluorescence. Other limax amoebae, such asVahlkampfia, Acanthamoeba, Hartmannella , andSchizopyrenus sp. gave negative responses with the prepared antisera. The indirect fluorescent-antibody technique allows the identification ofN. fowleri in a mixed culture of bothN. fowleri andN. gruberi strains. Twenty-twoNaegleria isolated from a suspected stream, other surface waters, and muddy soil could be excluded from thefowleri species with the indirect fluorescent-antibody technique. The results obtained demonstrate that this immunological technique is a valid method for the rapid identification ofN. fowleri trophozoites.