TABLE 4.

Amino acid substitutions in the ftsI gene in H. influenzae

GroupAmino acid substitutionsMIC AMX range (μg/ml)Overall geometric meanbNo. of isolates
Near STVK motifThr-352Lys-355Leu-356Met-377Met-391Ala-437Ile-449Ile-475Gly-490Surrounding KTG motif
Lys-344Ile-348Asp-350Ala-502Arg-517Ile-519Asn-526Ala-530Thr-532AMXAMC19972007Total
IHisSer1-≥641.592.00224
IIaLys0.5-42.001.7433
LysSer1-422
IIbValLys2-42.002.0022
GluValLys111
AsnIleValLys1-≥644610
AsnIleGluValLys2-16123
AsnSerValLeuLys122
IIcThrLys0.5-322.181.807613
AsnThrLys1-≥646814
IIdValLys0.5-≥642.002.00437
MaIle≤0.250.520.5311
Leu0.522
Thr≥6411
Asn≤0.25-≥648311
AsnSer0.5224
Val0.511
Val0.511
Ser0.522
ArgAsnGlyThrValIle0.511
ArgAsnGlyThrValIleSer≤0.2511
  • a M, miscellaneous.

  • b The amoxicillin (AMX) value was calculated for the β-lactamase-negative isolates only (n = 149); the amoxicillin-clavulanic acid (AMC) value was calculated for the entire collection (n = 197).