TABLE 2.

Amino acid changes in GyrA, GyrB, ParC, and ParE QRDR fragments in 32 S. maltophilia clinical strains and quinolone susceptibilities with and without CCCP and reserpine

Strain (patient origin)MIC (μg/ml)Amino acid (nucleotides) at indicated positiona
CiprofloxacinNalidixic acidGyrAGyrBParC, 80ParE
708590103112113119124407437465477485507525545
ATCC 136370.1-24-8Val (GTC)Val (GTC)Val (GTC)Val (GTC)Ile (ATC)Asp (GAT)Ala (GCA)Glu (GAA)Ser (AGC)Asp (GAC)Met (ATG)Ile (ATC)Ser (AGC)Ile (ATC)Lys (AAG)Leu (CTG)Ser (TCG)
10 strainsb0.1-642->128c
Sm199 (non-CF)0.18Gly (GGC)Glu (GAC)Val (GTC)Ser (AGC)Leu (CTG)Val (GTG)Thr (ACC)
Sm196 (CF)0.18Val (GTC)Leu (GTC)Val (GTG)Ala (GCC)
Sm202 (non-CF)0.18Leu (CTG)Val (GTG)Thr (ACC)Val (GTG)Arg (AGG)
Sm65 (non-CF)0.25 (0.06)d1 (0.12)e
Sm63 (non-CF)0.5 (0.06)e (0.12)d8
Sm66 (non-CF)0.58Ala (GCC)
Sm36 (CF)12Val (GTG)
Sm83 (CF)18Leu (CTG)Val (GTG)Thr (ACC)Val (GTG)Arg (AGG)
Sm24 (CF)116Leu (CTG)Val (GTG)Ala (GCC)
Sm85 (non-CF)116Leu (CTG)Val (GTG)Ala (GCC)
Sm230 (CF)4 (0.5)e16Thr (ACG)Leu (CTG)Val (GTG)Thr (ACC)Val (GTG)
Sm14 (CF)416Leu (CTC)Val (GTG)Thr (ACC)Val (GTG)
Sm203 (CF)4 (1)e32His (CAT)
Sm4 (CF)464Gly (GCA)Leu (CTG)Val (GTG)Thr (ACC)Val (GTG)Arg (AGG)
Sm50 (CF)8 (2)e32
Sm8 (CF)832Leu (CTG)Val (GTG)Ala (GCT)
Sm219 (non-CF)8 (2)e64 (4)eVal (GTC)Leu (CTG)Val (GTG)Ala (GCC)
Sm117 (non-CF)1632Val (GTC)Arg (AGA)Leu (CTG)Val (GTG)Thr (ACC)
Sm98 (CF)16128Leu (CTG)Val (GTG)Thr (ACC)Val (GTC)Arg (AGG)
Sm28 (CF)32 (8)e64 (2)eThr (ACC)
Sm104 (non-CF)32128Gly (GGC)
Sm226 (non-CF)64128Leu (CTG)Val (GTG)Thr (ACC)Val (GTC)
  • a Amino acid position corresponds to the amino acid numbering of the topoisomerase II and IV subunits of E. coli.

  • b Three strains were from CF patients, and seven strains were from non-CF patients.

  • c —, no change with respect to S. maltophilia ATCC 13637 QRDR sequence.

  • d Values in parentheses are MICs in the presence of 10 μg of reserpine per ml. These values are indicated only when the decreases were 2 or more doubling dilutions.

  • e Values in parentheses are MICs in the presence of 0.5 μg of CCCP per ml. These values are indicated only when the decreases were 2 or more doubling dilutions.