Table 2. MIC fold-increase and mutations in gyrA, gyrB and marR among nal^R, cip^R, and levo^R mutants of E. coli K-12 (MG1655).

S.No.	Antibiotic	MIC WT (ug/ml)	MIC fold increase of mutants			Resistance mutation			Total number of nalR, cipR and levoR mutants	Number of gyrA, gyrB and marR mutants
			Nal	Cip	Levo	gyrA	gyrB	marR
	Nalidixic acid	10							11
1			64			A67S				2
2			256			S83L				6
3			128			D87G				2
4			64				D426N			1
	Ciprofloxacin	0.015							24
1				64		G81C/D				3
2				128		S83L				4
3				32		S83W				2
4				64		D87Y/G/N				7
5				32			H281L			1
6				32			S464Y			1
7				16			L509G			1
	Levofloxacin	0.031							21
1					8	G81C				1
2					16	S83L				8
4					8	D87G				1
3					16	D87G		R27P		1
5					16			E10stop		1
6					16			L33R		1
7					8			Q42E		1
8					4			L64fs		1
9					16			G69E		1
10					8			T102S		1
11					8			Q117stop		1
12					4			L123S		1
13					8			N126fs		1