TABLE 7.

Frequency of DNA changes detected in the QRDR, including gyrA, gyrB, parC, and parE genes in fluoroquinolone-resistant MRSA and MSSA clinical isolates from blood culture^b

gyrA				parC				parE
DNA mutations	Total n (%)	MRSA n (%)	MSSA n (%)	DNA mutations	Total n (%)	MRSA n (%)	MSSA n (%)	DNA mutations	Total n (%)	MRSA n (%)	MSSA n (%)
C251T	59 (94)	57 (95)	2 (67)	C239T	53 (84)	51 (85)	2 (67)	C1351T	16 (25)	16 (27)	0 (0)
A501G	57 (90)	55 (92)	2 (67)	A456G	9 (14)	9 (15)	0 (0)	G1294A	10 (16)	8 (13)	2 (67)
T513A	48 (76)	46 (77)	2 (67)	A475C	9 (14)	9 (15)	0 (0)	1205delA	7 (11)	7 (12)	0 (0)
C525A	43 (68)	41 (68)	2 (67)	C239A	8 (13)	8 (13)	0 (0)	A1295T	1 (2)	1 (2)	0 (0)
T253C	14 (22)	13 (22)	1 (33)	G250A	8 (13)	8 (13)	0 (0)	C1318T	1 (2)	1 (2)	0 (0)
361delA	8 (13)	8 (13)	0 (0)	A251G	4 (6)	4 (7)	0 (0)	G1459A	1 (2)	1 (2)	0 (0)
C525G	7 (11)	7 (12)	0 (0)	T376C	4 (6)	4 (7)	0 (0)	NDa	33 (52)	32 (53)	1 (33)
543delG	6 (10)	6 (10)	0 (0)	57delA	1(2)	1 (2)	0 (0)
391delA	5 (8)	5 (8)	0 (0)	585delT	1 (2)	1 (2)	0 (0)
A570C	4 (6)	4 (7)	0 (0)	608delA	1 (2)	1 (2)	0 (0)
G451A	4 (6)	4 (7)	0 (0)	612delA	1 (2)	1 (2)	0 (0)
T563A	4 (6)	4 (7)	0 (0)	C397T	1 (2)	1 (2)	0 (0)
A418G	3 (5)	3 (5)	0 (0)	C457G	1 (2)	1 (2)	0 (0)
G262A	3 (5)	3 (5)	0 (0)	ND	2 (3)	1 (2)	1 (33)
451delG	2 (3)	2 (3)	0 (0)
527insG	2 (3)	2 (3)	0 (0)
T500C	2 (3)	2 (3)	0 (0)
563delT	1 (2)	1 (2)	0 (0)
ND	1 (2)	0 (0)	1 (33)

^a ND, not detected.

^b Empty cells indicate that the corresponding DNA mutation was not observed for that gene, as mutation types vary among gyrA, parC, and parE.