TABLE 2.

Distribution of QRDR mutations of gyrA and parC in the PMQR-positive E. coli isolates

PMQR gene(s)	QRDR mutation(s)a		No. of isolates	MIC range for ciprofloxacin (μg/ml)
	gyrA	parC
oqxAB(n = 60)	None	None	25	0.008-0.5
	L83	None	4	0.25-1
	L83	I80	3	4
	L83	G84	1	4
	L83	R84	1	1
	L83, N87	None	1	>32
	L83, N87	R80	1	32
	L83, N87	I80	20	16-32
	L83, N87	K84	2	32->32
	L83, N87	I80, A84	2	>32
qepA	L83, N87	I80	4	32->32
	L83, N87	K84	1	>32
oqxAB, qnrD	L83	R80	1	2
oqxAB, qnrS1	None	None	5	1-2
oqxAB, qnrB6, aac(6′)-Ib-cr	None	None	1	2

^a“L83” represents a mutation at codon 83 to the L codon, etc. “None” indicates the wild type.