Detection of a novel restriction fragment length polymorphism type in Naegleria fowleri (free-living amoeba) isolates from electricity power stations in England and France

Abstract

Summary The human pathogenic free-living amoeba Naegleria fowleri was isolated from two electricity power stations in the North of England. Comparison with isolates from a similar site in France showed the strains to have agarose gel restriction fragment length polymorphisms (RFLPs) in common with those from the antipodes. However, hybridisation of Bgl II digests with a repetitive element clone of chromosomal DNA detected additional RFLPs that uniquely characterised the strains. This RFLP profile was not identified in N. fowleri isolates from the natural hot springs in Bath, England, suggesting that the two sites have been colonised independently. Differences in RFLP types were also detected within other isolates from Europe that have not previously been observed. In addition, a strain of N. fowleri isolated from the first case of primary amoebic meningoencephalitis in Hong Kong was found to be identical to European strains. The findings of this study indicate that mixed populations of N. fowleri can occur within countries and that the species cannot be differentiated by the continent of origin on the basis of RFLP type as has previously been reported.