TABLE 2.

Amino acid substitutions in ParC and GyrA of S. dysgalactiae subsp. equisimilis isolates with different levels of resistance to levofloxacin^a

Allelesb	Amino acid coding change at the indicated position								MIC range (μg/ml)	No. of isolates
	GyrA				ParC
	81	85	142	79	83	91	140	166
gyrA04, parCc	S81F			S79F					>32	5
gyrA04, parC15	S81F			S79F		N91D			>32	5
gyrA04, parC17	S81F			S79F		N91D	P140S		>32	4
gyrA02, parC17	S81Y			S79F		N91D	P140S		>32	1
gyrA03, parC08		E85K		S79F					>32	1
gyrA03, parC06		E85K		S79Y					>32	1
gyrA04, parC09	S81F				D83N				8, 24, >32	3
gyrA04, parC13	S81F			S79A					12	1
gyrA03, parC10		E85K			D83G				8	1
gyrA04, parC14	S81F					N91D			4	1
gyrA01, parC04				S79F					3	1
gyrA01, parC17				S79F		N91D	P140S		1.5-3	3
gyrA01, parC19				S79A		N91D	P140S		2	1
gyrA01, parC12								G166E	1	1
gyrA01, parC03				S79P					0.75	1
gyrA01, parCd						N91D	P140S		0.19-0.5	5
gyrA01, parC14						N91D			0.5-0.75	3
gyrA05, parC05			D142N						0.38-0.5	4
gyrA01, parCe									0.38-0.75	14

^aA total of 56 isolates with different levels of resistance to levofloxacin were tested.

^bThe allele numbers were attributed on the basis of the DNA sequence of the QRDR of each gene. When more than one allele that resulted in the same amino acid sequence was found, no number is indicated and the alleles found and the number of isolates presenting them are indicated in the subsequent footnotes.

^cFor parC04, n = 3; for parC08, n = 2.

^dFor parC16, n = 4; for parC18, n = 1.

^eFor parC01, n = 5; for parC02, n = 3; for parC07, n = 5; for parC11, n = 1.