Fig 1.
The computational screening and experimental validation protocol followed to identify putative CMY-10 inhibitors for combination therapy against multi-drug resistant Enterobacteriaceae.
Fig 2.
Apolar (green), hydrogen bonding donor (blue) and acceptor (red) and negatively (orange) charged SILCS FragMaps overlaid on the active site of CMY-10. The crystal binding mode of IMP in the CMY-10-IMP complex is shown. Consistencies between the crystal binding mode of IMP with FragMaps are shown by arrows.
Fig 3.
Pharmacophore model for R2 site.
Hydrophobic, hydrogen bonding donor and acceptor, and anionic features are shown in cyan, blue, red and dark red colors, respectively. Crystal binding mode of IMP is also shown with surrounding protein residues labeled.
Fig 4.
Pharmacophore model for R1-R2 site.
Hydrophobic and hydrogen bonding acceptor features are shown in cyan and red colors, respectively. Crystal binding mode of Ceftazidime with AmpC is also shown with surrounding protein residues labeled. CMY-10 residues are shown in green colored carbons and AmpC residues are represented in pink colored carbons.
Fig 5.
BL-activity and LGFE scores of identified lead compounds.
Blue bars showing BL activity with red color indicating LGFE along with positive control in black.
Table 1.
BL-activity and LGFE scores of lead compounds identified as inhibitors.
Fig 6.
Patterns of genomic plasmid from E. cloacae (lane 2), E. agglomerans (lane 3), E. alvei (lane 4), and lane 1 (100-bp stepwise ladder) show band patterns of ladder fragments (sizes in base pairs are indicated on the edge of the gel).
Table 2.
Antibacterial activity of lead compounds against β-lactamase producer clinical bacterial isolates.
Table 3.
Minimum inhibitory concentration of compound 11 against clinical bacterial isolates.
Fig 7.
Graphical representation of synergetic effect of the computationally screened compounds-cefixime with positive control.
Table 4.
Synergistic effect of compound 11 with different concentration against clinical isolates.
Fig 8.
Scanning electron microscopy (SEM) analysis (A) Effects of control on E. Cloacae (B) Effects of lead compound 11 in combination with antibiotic, cefixime against Enterobacter cloacae. (C) Effects of control on E. alvei, (D) Effects of lead compound 11 in combination with antibiotic, cefixime against E. alvei. (E) Effects of control on E. agglomerans (F) Effects of lead compound 11 in combination with antibiotic, cefixime against E. agglomerans. The red arrows indicate the morphological changes exhibited on bacterial cell wall after the use of combination therapy.
Fig 9.
BL activity of further screened compounds with negative control (Chembridge ID: 5524250) in green color and positive control in red color.