The minimum bactericidal concentration (MBC) is the lowest concentration of an antibacterial agent required to kill a particular bacterium. It can be determined from broth dilution minimum inhibitory concentration (MIC) tests by subculturing to agar plates that do not contain the test agent. The MBC is identified by determining the lowest concentration of antibacterial agent that reduces the viability of the initial bacterial inoculum by ≥99.9%. Antibacterial agents are usually regarded as bactericidal if the MBC is no more than four times the MIC. Because the MBC test uses colony-forming units as a proxy measure of bacterial viability, it can be confounded by antibacterial agents which cause aggregation of bacterial cells. Examples of antibacterial agents which do this include flavonoids and peptides.
^Medical microbiology, Mims and Playfair, Mosby Europe, 1993, 35.31.
^French GL (2006). "Bactericidal agents in the treatment of MRSA infections--the potential role of daptomycin". J. Antimicrob. Chemother.58 (6): 1107–17. doi:10.1093/jac/dkl393. PMID17040922.
^Cushnie TPT, Hamilton VES, Chapman DG, Taylor PW, Lamb AJ (2007). "Aggregation of Staphylococcus aureus following treatment with the antibacterial flavonol galangin". Journal of Applied Microbiology103 (5): 1562–1567. doi:10.1111/j.1365-2672.2007.03393.x. PMID17953567.
^Suarez M, Haenni M, Canarelli S, Fisch F, Chodanowski P, Servis C, Michielin O, Freitag R, Moreillon P, Mermod N (2005). "Structure-function characterization and optimization of a plant-derived antibacterial peptide". Antimicrobial Agents and Chemotherapy49 (9): 3847–3857. doi:10.1128/AAC.49.9.3847-3857.2005. PMID16127062.