TABLE 6.

Integration frequencies obtained with IntI1 and VchIntIA in E. coli and V. cholerae strains

Participating sites	Integration recombination frequencya
	E. coli		V. cholerae
	IntI1	VchIntIA	IntI1	VchIntIA
attI1 × VCR2/1	(1.3 ± 0.5) × 10−2	<3 × 10−9	(3.7 ± 1.6) × 10−2	<1 × 10−7
attIVch × VCR2/1	<3 × 10−9	(5 ± 2.8) × 10−6	< 1 × 10−7	(1 ± 0.3) × 10−2

^aAverage±standarddeviationforthreeindependenttrials.