TABLE 1.

Complementation of elevated phase variation in 24-h-old colonies

A. baumannii strain	Plasmid	Phase variation frequency (%) ± SD	Fold change	P value
AB5075 (wild type)	pWH1266	0.033 ± 0.022
ΔompR mutant (O variant)	pWH1266	61.6 ± 5.8
	pompR	0.132 ± 0.189	466	<0.0001
ΔenvZ mutant (O variant)	pWH1266	13.4 ± 10.6
	penvZ	0.030 ± 0.027	446	0.4188
ΔompR ΔenvZ mutant (O variant)	pWH1266	43.8 ± 17
	pompRenvZ	0.038 ± 0.017	1,152	0.0001