TABLE 3.

Sequence variation at five loci

Gene	Fragment size (bp)	Mean G+C content (%)	No. of alleles	No. of polymorphic sitesa	No. of nucleotide substitutions per nucleo- tide site	dN/dSb
gyrB	554	40.5	8	14 (7)	0.0048	8.33
ddl	444	36.8	10	10 (1)	0.0020	62.01
pgm	402	40.4	12	7 (2)	0.0029	43.94
recP	541	44.7	8	36 (18)	0.0066	22.46
mleA	339	39.2	2	1 (0)	0.0011	0

^aNumber of silent polymorphic sites in parentheses.

^bCalculated by using the START program and expressed as the d_N/d_S ratio multiplied by 100.