Research Article
Detection of Carbapenemase-Producing Enterobacteriaceae in the Baltic Countries and St. Petersburg Area
Figure 2
MALDI-TOF MS spectrum showing ertapenem and its degradation products. Spectrum related to (a) positive control (Klebsiella pneumoniae metallo-β-lactamase positive): hydrolyzed decarboxylated product of ertapenem (450.5 Da); (b) incubated ertapenem solution: hydrolyzed decarboxylated product of ertapenem (450.5 Da), ertapenem molecule (476.5 Da), and ertapenem sodium adduct (498.5 Da); (c) pure ertapenem solution: hydrolyzed decarboxylated product of ertapenem (450.5 Da), ertapenem molecule (476.5 Da), ertapenem sodium adduct (498.5 Da), and ertapenem disodium adduct (520.5 Da); (d) New Delhi Metallo-β-lactamase-positive strain (Klebsiella pneumoniae): hydrolyzed decarboxylated product of ertapenem (450.5 Da); (e) negative control (noncarbapenemase-producing Klebsiella pneumoniae): hydrolyzed decarboxylated product of ertapenem (450.5 Da), ertapenem molecule (476.5 Da), and ertapenem sodium adduct (498.5 Da).
