IDENTIFICATION AND EPIDEMIOLOGIC TYPING OF NAEGLERIA-FOWLERI WITH DNAPROBES

Naegleria fowleri is a small free-living amoeboflagellate found in war m water habitats worldwide, The organism is pathogenic to humans, caus ing fatal primary amoebic meningoencephalitis, When monitoring the env ironment for the presence of N. fowleri, it is important to reliably d ifferentiate the organism from other closely related but nonpathogenic species. To this end, we have developed species specific DNA probes f or use in the rapid identification of N. fowleri from the environment. Samples were taken from the thermal springs in Bath, England, and cul tured for amoebae, Of 84 isolates of thermophilic Naegleria spp,, 10 w ere identified as N. fowleri by probe hybridization. The identity of t hese isolates was subsequently confirmed by their specific whole-cell DNA restriction fragment length polymorphisms (RFLPs). One DNA clone w as found to contain a repeated element that detected chromosomal RFLPs that were not directly visible on agarose gels, This enabled the furt her differentiation of strains within geographically defined whole cel l DNA RFLP groups, N. fowleri DNA probes represent a specific and pote ntially rapid method for the identification of the organism soon after primary isolation from the environment.