TABLE 4.

MICs of β-lactams for donor strain (MSC02236), recipient strain (FA1090), and various penA recombinants

StrainSubstitutions in PBP2 (aa)aMIC (μg/ml)
PenicillinCephalexinCefotiamCeftriaxoneCefiximeCeftibutenCefpodoxime
MSC02236101-5754512160.120.588
FA1090None0.1240.060.0040.0080.030.016
TF1101-5750.2512810.0160.1240.5
TF2101-5560.2512810.0080.1220.25
TF3101-5520.2512810.0160.1220.25
TF4101-5450.256410.0160.0620.25
TF5201-5750.2512810.0160.1240.5
TF6279-5750.2512810.0160.1240.5
TF7312-5750.2525610.0160.1240.5
TF8323-5750.251280.50.0040.030.50.06
TF9406-5750.25640.50.0080.030.50.06
TF10437-5750.251280.50.0160.0610.12
TF11504-5750.25640.50.0160.0610.12
TF12504-5450.12320.50.0080.030.250.06
  • a MSC02236 had alterations in PBP2 between amino acid (aa) positions 101 and 575 (each substitution is shown in Fig. 2, mosaic-1 sequence). The region that was acquired from MSC02236 through homologous recombination is indicated for recombinants.