TABLE 2.

Mean and maximum survival days of worms infected with L. pneumophila strains

Bacterial strain	Nematode age (days) at start of infection	Mean survival timea (days) ± SE	Maximum survival time (days)	No. of nematodes (no. of experiments)b
E. coli OP (control)	3.0	13.20 ± 0.45	23	115 (2)
L. pneumophila JR32	3.0	12.80 ± 0.34	20	116 (2)
E. coli OP (control)	7.5	10.20 ± 0.33	19	123 (2)
L. pneumophila JR32	7.5	7.40 ± 0.26***	14	117 (2)
E. coli OP (control)	7.5	10.17 ± 0.44	17	70 (1)
L. pneumophila LELA2883	7.5	10.50 ± 0.54	20	69 (1)
L. pneumophila LELA3118	7.5	10.00 ± 0.53	21	72 (1)
L. pneumophila LELA3473	7.5	9.76 ± 0.49	19	72 (1)
L. pneumophila LELA4432	7.5	9.62 ± 0.49	18	74 (1)
L. pneumophila LELA3244	7.5	11.12 ± 0.51	18	60 (1)
L. pneumophila LELA3393	7.5	9.64 ± 0.44	16	65 (1)
L. pneumophila LELA1718c	7.5	8.74 ± 0.43*	15	66 (1)
E. coli OP (control)	7.5	9.14 ± 0.38	17	78 (1)
L. pneumophila LELA1718c	7.5	9.49 ± 0.38	15	70 (1)
E. coli OP (control)	8.0	9.13 ± 0.45	14	48 (1)
L. pneumophila LELA1718c	8.0	7.33 ± 0.42**	13	48 (1)
L. pneumophila LELA4432	8.0	10.00 ± 0.52	18	46 (1)

^a*, **, and *** indicate a statistically significant difference from the control at P values of <0.05, <0.01, and <0.001, respectively.

^bEach experiment was performed in duplicate or triplicate.

^cWhen worms were infected with LELA1718 at 7.5 days after hatching, the strain showed weak virulence in one of two experiments. The 8-day-old worms seemed to be more vulnerable to the strain.