Antimicrobial activity of novel cobalt(II) complexes with Schiff base derived from L- cysteine and 2-substituted benzaldehyde

Aims: The aim of this study was to conduct antimicrobial analysis on novel Schiff base-derived cobalt(II) complexes (Co(L1)2 and Co(L2)2). Methodology and results: Synthesis of Co(II) Schiff base complexes was carried out by reacting Schiff bases with cobalt(II) chloride hexahydrate and spectroscopic analyses were used for characterization. Microbiological assays comprised the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of tested substances and the evaluation of their antibiofilm activity. A total of 11 bacteria were tested, including multidrug-resistant strains. Investigated compounds performed inhibitory activity against all tested bacteria, with the MIC value of 250 & mu;g/mL and 125 & mu;g/mL just for Escherichia coli ATCC 14169. Results regarding the antibiofilm properties suggest that investigated Schiff's base complexes have antibiofilm activity in a strain-specific and concentrationdependant manner. Conclusion, significance and impact of study: The current study showed that the novel complex compounds possess antimicrobial and antibiofilm properties against Gram-positive and Gram-negative bacteria. Since bacterial resistance to currently available antibiotics is rapidly increasing, further studies may provide information about using novel complexes as potential antimicrobial agents.