TABLE 3.

Sequence divergence within and between S. Enteritidis clades and subclades

Clade or subclade (no. of strains)	Mean no. of base differences ± SEa
	I	II	IIA	IIB	IIC	IID
I (47)	0.99 ± 0.41b
II (51)	13.74 ± 4.25	7.85 ± 1.79b
IIA (4)	8.61 ± 3.40		1.00 ± 0.68b
IIB (8)	10.23 ± 3.64		5.06 ± 1.86	1.07 ± 0.71b
IIC (17)	12.20 ± 4.53		6.09 ± 2.24	8.82 ± 3.11	0.46 ± 0.25b
IID (18)	19.34 ± 5.60		13.97 ± 3.61	16.14 ± 3.89	9.86 ± 2.71	1.29 ± 0.46b

^aMean nucleotide pairwise sequence variation among the five S. Enteritidis clades and subclades described in Fig. 2. Distance analysis was conducted with MEGA 5 (34).

^bIntraclade distance.