Table 3. Point mutations identified in the QRDRs of gyrA, gyrB, parC, and parE genes in fluoroquinolone-resistant NAS strains

NAS species		No. of FQ-resistant isolates (%)	Mutations in QRDRs				Total No.
			gyrA	gyrB	parC	parE
CoVS	Staphylococcus agnetis (51)	11 (21.6)	S84L	-	S80L	-	10
			S84L	-	S80L, Y56H	-	1
	Staphylococcus chromogenes (17)	7 (41.2)	S84L	-	-	-	6
			S84L	-	R87I, S89T	-	1
CoNS	Staphylococcus arlettae (2)	1 (50)	S84L	-	T80I	-	1
	Staphylococcus cohnii (5)	1 (20)	S84F, V158A	-	-	-	1
	Staphylococcus condimenti (1)	1 (100)	S84F	-	-	-	1
	Staphylococcus epidermidis (15)	1 (6.7)	S28E, V29C, S84F	-	Q81K, D81H, G107A, S108R, I109L	-	1
	Staphylococcus gallinarum (12)	8 (66.7)	S84L	-	Y56F, Y74F, S80I, G92D		8
	Staphylococcus haemolyticus (1)	1 (100)	S84L	-	-	-	1
	Staphylococcus lentus (5)	3 (60)	T172A	-	S80V	-	1
			T172A	-	S80L	-	2
	Staphylococcus saprophyticus (20)	6 (43.8)	S84L	-	S80L, R96C	-	6
	Staphylococcus sciuri (1)	1 (100)	S84L, T172A	S567A	S80I	-	1
	Staphylococcus simulans (27)	5 (18.5)	S84L	A512R	-	T379K	1
			S84L, D105N, A119F	-	-	T379K	1
			S84L, A132S, A173S	A512R	-	T379K	1
			S84L, A132S	E490G, S494T	-	T379K	1
			S84L, A132S, A173S	E490G, S494T	-	T379K	1
	Staphylococcus xylosus (49)	11 (22.4)	S84L	S567A	F160L, V165I, Y195F, I209V	-	10
			S84L	S567A	D148H, F160L, L164W, V165I, S168N, D178H, G185R, V187L, Y194F, K207T, Y208S, I209V, D213G	-	1

QRDRs, quinolone resistance determining regions; NAS, non-aureus staphylococci; FQ, fluoroquinolone; CoVS, coagulase-variable staphylococci; CoNS, coagulase-negative staphylococci.