3.5. MALDI-TOF MS spectral analysis of CFEC- ESBL bacteria
Although general information was obtained firstly with PCA analyses of
all 122 CFEC bacteria, the study focused on comparing the results of
MALDI-TOF MS-based PCA analysis of 35 E. coli bacteria with ESBL
detected with the results of other phenotypic methods. A representative
mass spectrum (CFEC-ESBL-68) showing ESBL characteristics and gel images
(virtual gel images; VGI) of 35 CFEC-ESBLs are given in Figure 2. In
this respect, when the mass spectrum of the CFEC-ESBL-68 isolate in
Figure 2A and the VGIs of all CFEC-ESBLs are examined, especially the
high abundance (intensity) peptide (m/z; 5107 Da, 6270 Da, 7290 Da, 9085
Da) and 9762 Da) protein (m/z; 10489 Da) projections appear to be nearly
identical for each. In this context, it is considered that there is no
major difference when looked at roughly. However, when detailed analyzes
of all components of PCA analyses were made (dendrogram, 2D/3D scatter
plotting, variance, composite correlation index, etc.), it was
determined that there were significant differences between theseE. coli with ESBL characteristics.