Table 1. Summary of loci statistics included in the MLST scheme (dnaE, gyrB, recA, dtdS, pntA, pryC and tnaA) such as fragment length, number of alleles and polymorphic sites, nucleotide diversity (π), rates of nonsynonymous (d _N) and synonymous (d _S) mutations, and tests of selection (d _N/d _S).

Chromosome	Locus	Fragment length (bp)	Alleles	Polymorphic sites	π	d N a	d S a	d N/d S a
I	dnaE	557	19	30	0.0120	0.0013	0.0584	0.0223
	gyrB	592	18	32	0.0103	0.0002	0.0559	0.0044
	recA	729	21	51	0.0206	0.0007	0.1160	0.0059
II	dtdS	458	18	34	0.0192	0.0000	0.0979	0.0000
	pntA	430	14	22	0.0107	0.0017	0.0557	0.0313
	pyrC	493	19	26	0.0112	0.0022	0.0462	0.0482
	tnaA	423	17	23	0.0118	0.0015	0.0522	0.0278

^aRate of nonsynonymous (d _N) and synonymous (d _S) substitutions where d _N/d _S<1 indicates that the loci is subject to purifying selection.