Table 1.
Characterization of the 149 bacterial strains analyzed and data summary of imipenem hydrolysis assay utilizing MALDI-TOF MS.
Figure 1.
MALDI-TOF MS analysis of imipenem.
(A) Imipenem and its natural degradation product. (B) Mass spectra of imipenem and its natural degradation product as determined using the Ultraflex mass spectrometer.
Figure 2.
Mass spectra of the imipenem hydrolysis assay with a carbapenem-resistant A. baumannii strain.
Incubation at 37°C during 4 h; NaCl 0.45%; imipenem concentration 0.25 mg/mL. Units of the x axis represent the mass per charge in Daltons [m/z (Da)] and that of the y axes, the relative intensity (a.u., arbitrary units).
Figure 3.
Mass spectra of the imipenem hydrolysis assay with a carbapenem-sensitive A. baumannii strain.
Incubation at 37°C during 4 h; NaCl 0.45%; imipenem concentration 0.25 mg/mL Units of the x axis represent the mass per charge in Daltons [m/z (Da)] and that of the y axes, the relative intensity (a.u., arbitrary units).