Table 6.

Mutations in gyrA and gyrB that were associated with levofloxacin resistance

No.	Strain	MIC (mg/L)	Profile	gyrA mutations	gyrB mutations
1	DM8	0.25	Sensitive	None	None
2	DM32	0.25	Sensitive	None	None
3	DM57	0.25	Sensitive	None	None
4	DM86	0.25	Sensitive	None	None
5	DM95	0.25	Sensitive	None	None
6	DM9	16	Resistant	None	None
7	DM10	32	Resistant	N87I	None
8	DM14	2	Resistant	D91G, E193D, I194F, A197F	None
9	DM18	16	Resistant	N87T, D91N	None
10	DM43	2	Resistant	N87T, D91N	None
11	DM44	16	Resistant	N87T, A97V	None
12	DM49	32	Resistant	N87A	D435N, S479G
13	DM50	2	Resistant	E58G, G75V, D91G, Q98L	None
14	DM51	2	Resistant	D91N	None
15	DM60	2	Resistant	D91Y, A134V, D145N	None
16	DM62	2	Resistant	D91N	S479G
17	DM71	32	Resistant	N87I	S479G
18	DM73	32	Resistant	None	None
19	DM75	32	Resistant	N87I	None
20	DM96	4	Resistant	None	None
21	DM103	16	Resistant	N87I, D91N, I162T	None
22	DM115	2	Resistant	N87K	None
23	DM142	4	Resistant	N87T, D91N	None
24	DM146	16	Resistant	N87T	None
25	DM147	2	Resistant	D91Y	None
26	DM148	2	Resistant	None	None
27	DM150	16	Resistant	N87T, D91N, F149V	None
28	DM152	8	Resistant	N87I	Y514F

MIC = minimum inhibitory concentration. None: no specific mutations were identified; N87I means isoleucine replaced asparagine in amino acid position 87. We ignored mutations that were present in both sensitive and resistant strains.