Conserved genes in a path from commensalism to pathogenicity: comparative phylogenetic profiles of Staphylococcus epidermidis RP62A and ATCC12228

Table 2 Comparison of SNP frequency and distribution into different functional groups

Groups^a	No.CDS	n+s	n^b	s	n/s	P _I ^c	P _II	P _III
I	11	112	47	65	0.723
II	6	84	34	50	0.68	0.834
III	48	400	99	301	0.329	0.000*	0.003*
Total	931	7322	2151	5171	0.416	0.003* ^d	0.025* ^d	0.047* ^d

^aGroups defined as (I) genes whose products are virulence factors and genomic islands in both S. epidermidis genome; (II) genes whose products are surface proteins; (III) genes whose products belong to translation, ribosomal structure and biogenesis catalog according to COG.
^b(n) number of non-synonymous SNPs; (s) number of synonymous SNPs; (n/s) ratios of non-synonymous SNPs vs. synonymous SNPs.
^c P-value from χ² test for the difference in n/s ratios in all the pairwise comparisons among the three functional groups (* indicates p < 0.05).
^dP-value from χ² test for the difference in n/s ratios between the three functional groups and total without themselves (* indicates p < 0.05).

ISSN: 1471-2164