Designing of potent inhibitors for metallo-beta-lactamases producing Escherichia coli in molecular specification hereto.

The rapid spread of Metallo-β-Lactamases producing Gram-negative bacteria in Pakistan is alarming and novel inhibitors with multi inhibition potential are required. In the current study, an effort was made to identify the resistance genes of MBLs producing E. coli and single inhibitor was designed having the potential to block all resistant proteins. Results showed that out of 573 clinical isolates, 14.1% MBLs producers have NDM-1 (27.2%) and VIM (13.6%) gene. The isolates were resistant to MEM, AMP, AMC, FEP, CTX, LEV and ATM, while effective antibiotics were TGC, CO, FOS and AK with MICs ranging from 4 to >32μg/ml. RECAP synthesis was used for de-novo discovery of 1000 inhibitors and protein crystal structures were retrieved from PDB. Active sites were identified in each protein and to improve ADMET properties, Lipinski's rules of five was applied. Placement of the ligand was done by London dG algorithm implemented in MOE. For final refinement, GBVI/WSA dG algorithm was used. Based on docking score, visual inspection of ligands interaction with key residues, binding affinity and binding energy of ligands with proteins, 10 compounds were selected for MBLs proteins which presented best ADMET properties, binding energy and affinity than the reported ones.