Table 3. Expression of phase 2 antigen and phase variation frequency.

	Genotypea		Selectability	Phase variation
Parental strain	fljA	hin	of phase 2b	frequencyc
L-3900	WT	WT	+	1.84×10−4
	A46T	WT	+	9.11×10−5 *
	WT	R140L	-	<10−6
	A46T	R140L	-	<10−6
L-3287	WT	WT	+	<10−6
	A46T	WT	-	ND
	WT	R140L	-	ND
	A46T	R140L	-	ND

^aWT, wild type; A46T and R140L, amino acid substitutions.

^b+, selectable; -, not detected.

^cND, not done;

^*, significantly lower than parental strain (p = 0.04).