Species specificity of a monoclonal antibody produced to Naegleria fowleriand partial characterization of its antigenic determinant

Monoclonal antibody (Mab) 5D12 against Naegleria fowleri was analyzed for s pecies specificity. Mab 5D12 reacted with a ubiquitous epitope present on t he membrane of N. fowleri but not with soluble antigens, The Mab did not re act with N. lovaniensis, N. gruberi, N. australiensis, or Acanthamoeba cast ellanii. The decreased reactivity of Mab 5D12 with N. fowleri observed afte r periodate oxidation, after digestion of carbohydrate moieties by three gl ycosidases, or after treatment of amebas with tunicamycin strongly suggests that the antigenic determinant has a polysaccharide component. Inhibition of the reactivity of Mab 5D12 by soluble saccharides supports the idea that N-acetyl or amino groups may play an important role in the recognition of the carbohydrate component of the epitope by the Mab. The specificity of Ma b 5D12 makes this an ideal reagent for the identification of N. fowleri in environmental samples or in clinical specimens.