Table 2.

Efficiency of lysogenization of E. coli MG1655 (wild-type) and ppGpp⁰ hosts with Shiga toxin-converting bacteriophages

Phage	Efficiency of lysogenizationa with the indicated host and MOI
	Wild type (MG1655)			ppGpp0
	1	5	10	1	5	10
ϕ24B	0.38 ± 0.02	0.47 ± 0.02	0.66 ± 0.02	0.40 ± 0.03	0.51 ± 0.01*	0.65 ± 0.08
933W	0.40 ± 0.01	0.56 ± 0.01	0.78 ± 0.08	0.28 ± 0.02*	0.51 ± 0.04*	0.59 ± 0.02*
P22	0.25 ± 0.02	0.27 ± 0.01	0.62 ± 0.02	0.28 ± 0.03	0.47 ± 0.01*	0.60 ± 0.05
P27	0.32 ± 0.03	0.48 ± 0.02	0.64 ± 0.04	0.29 ± 0.01	0.46 ± 0.03	0.58 ± 0.01*
P32	0.28 ± 0.03	0.52 ± 0.02	0.69 ± 0.03	0.31 ± 0.10	0.39 ± 0.03*	0.66 ± 0.06

^aA value of 1 would correspond to 100% lysogenization efficiency, and a value of 0 would correspond to no lysogens found. The presented values reflect these theoretical values. The numbers are mean values from 3 experiments ± SD. Asterisks (marked only for the ppGpp⁰ host) indicate statistical significance of differences (P < 0.05, assessed by t test) between results obtained for wild-type and ppGpp⁰ hosts under the same conditions (phage and MOI). Differences in the mean fold change values (ppGpp⁰ host versus wild type), cumulative for all MOI conditions in each phage, did not reach statistical significance in the t test (P values for ϕ24B, 933W, P22, P27, and P32 were 0.184, 0.094, 0.300, 0.184, and 0.635, respectively).