Anti-methicillin resistant Staphylococcus aureus activity, synergism with oxacillin and molecular docking studies of metronidazole-triazole hybrids.

MRSA causes 60-70% of Staphylococcus aureus infection in hospitals and it has developed resistance against the currently available drugs. Interestingly, a series of 35 metronidazole-triazole hybrids on screening against MRSA were found to be active. Compound 22 was found to be effective at 4 μg/mL concentration against nine strains of MRSA. The inhibitory activity was further enhanced upto 1 μg/mL when this compound was used in combination with oxacillin in 1:1 ratio. All the compounds were found to be non-toxic in THP-1 cell line upto a concentration of 50 μM. The time-kill kinetics studies suggested bacteriostatic nature of the compounds. In silico studies show that these compounds interact with Thr600, Ser598, Asn464, His583 and Tyr446 in the active site of PBP2a crystal structure from MRSA.