Cytopathogenicity of Naegleria fowleri in mammalian cell cultures

A total of 13 strains of Naegleria fowleri were cytopathogenic for lung, kidney, foreskin, ovary, connective tissue, neuroblastoma, laryngeal carcinoma, and cervical carcinoma mammalian cell lines. The strains of N. fowleri varied considerably in their ability to produce a cytopathic effect (CPE). Likewise, the different mammalian cell lines exhibited varying degrees of susceptability to the cytopathogenicity of the amebae. The African green-monkey kidney (Vero) cell line proved to be useful for assessing the cytopathogenic potential of N. fowleri strains. Although one strain failed to produce CPE in Vero-cell cultures, it did so in the two neuroblastoma cell lines. Other factors affecting the extent of CPE produced were incubation temperature, ameba: mammalian cell ratio, and the length of time during which amebae were maintained in cell culture.