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

Abstract

The indirect fluorescent-antibody technique was used to assess a rapid method for identification of amoebae belonging to the genus Naegleria . Thirty-eight Naegleria and eight other limax amoeba strains were examined by using one N. gruberi and two N. fowleri antisera. All pathogenic Naegleriae , most of which originated from fatal cases of primary amoebic meningo-encephalitis, were identified as belonging to the fowleri species. Most of the N. gruberi strains showed irregular fluorescence. Other limax amoebae, such as Vahlkampfia, Acanthamoeba, Hartmannella , and Schizopyrenus sp. gave negative responses with the prepared antisera. The indirect fluorescent-antibody technique allows the identification of N. fowleri in a mixed culture of both N. fowleri and N. gruberi strains. Twenty-two Naegleria isolated from a suspected stream, other surface waters, and muddy soil could be excluded from the fowleri species with the indirect fluorescent-antibody technique. The results obtained demonstrate that this immunological technique is a valid method for the rapid identification of N. fowleri trophozoites.