Isolation of Naegleria fowleri from the cooling pond of an electric power plant in France.

Eleven strains of Naegleria have been isolated from 126 samples of the cooling pond of an electric power plant near Metz, France. Three strains showed specific characters of N. fowleri (pathogenicity for mice after intranasal instillation, immunofluorescence with anti N. fowleri serum and non-agglutination with ConA up to 1 mg/ml. Some particular characteristics were noted; the cysts showed a high number of pores and the pathogenicity was is lower using Swiss mice than using NMRI mice. The need for a standardization of methods for isolation and characterization are discussed as well as the occurrence of N. fowleri at the site.