TABLE 1.

Mortality observed in mice after intranasal instillation of different N. fowleri strains^a

Strain	Isolation (day/mo/yr)	Initial N. fowleri concn in water (NPP/liter)	Dose/mouse	No. of mice	Mortality (%)	MTDb ± SD
D98.2.1.h10	14/05/98	871	47,600	20	100	6.9 ± 0.71
D98.1.3.f13∗	05/03/98	95	34,000	13	100	5.3 ± 0.75
G98.1.1.h1	12/03/98	440	24,000	9	100	5.4 ± 0.52
G98.1.2.e23	12/03/98	34	20,000	11	100	5.3 ± 0.46
G98.2.3.f8a	06/05/98	588	14,700	10	100	5.2 ± 0.42
D98.2.1.h10	14/05/98	871	13,300	10	100	5.9 ± 0.56
S-L98.2.1.e10a	08/09/98	46.5	7,500	10	100	7.5 ± 0.97
Chi98.2.1.d8a	08/09/98	45.6	5,500	10	100	76 ± 1.26
Cat98.1.2.d6b	24/08/98	0.5	5,500	10	100	9.4 ± 1.26
D98.2.1.h10	14/05/98	871	4,570	20	100	11.7 ± 5.56
S-L98.2.1.f17	08/09/98	46.5	3,400	20	100	7.6 ± 1.04
S-L98.2.1.f17	08/09/98	46.5	1,930	10	90	7.55 ± 1.42
D98.2.1.h10	14/05/98	871	550	20	70	16.3 ± 7.36
S-L98.2.1.f17	08/09/98	46.5	370	20	85	9.3 ± 2.03
S-L98.2.1.f17	08/09/98	46.5	70	20	30	11.5 ± 2.26

^aItalics indicate initial experiments effected without successive dilutions. 

^bMTD, mean time to death (in days).