The key difference between MBC and MIC is that MBC is the lowest concentration of antimicrobial agent that will prevent the growth of an organism after subculture onto a media containing no antibiotics, while MIC is the lowest concentration of an antimicrobial agent that will inhibit the visible in vitro growth of a microorganism after overnight incubation.
MBC and MIC are two microbiological tests used to evaluate germ killing activity of antimicrobial agents. These tests evaluate antimicrobial agents for their efficacy. Both these tests are extremely important while manufacturing new antimicrobial drugs and are performed by qualified microbiologists.
CONTENTS
1. Overview and Key Difference
2. What is MBC
3. What is MIC
4. Similarities – MBC and MIC
5. MBC vs MIC in Tabular Form
6. Summary – MBC vs MIC
What is MBC?
MBC or minimum bactericidal concentration is the lowest concentration of antimicrobial agent that will prevent the growth of an organism after subculture onto a media containing no antibiotics. It is also known as the lowest concentration of antimicrobial agent that is required to kill a bacterial over a fixed extended period (18 to 24 hours) under a specific set of conditions. Therefore, MBC shows the lowest level of antimicrobial agents resulting in microbial death. MBC (minimum bactericidal concentration) and MFC (minimum fungicidal concentration) often refer to the lowest concentration of an antimicrobial agent that reduces the viability of microorganisms by 99%.
Generally, an MBC is done after a MIC test. Moreover, antimicrobial agents are generally considered to be bactericidal if the MBC is no more than four times greater than the MIC. Furthermore, MBC and MFC are powerful methods to determine germ killing activity of several antimicrobial agents at once in screening processes.
What is MIC?
MIC or minimum inhibitory concentration is the lowest concentration of an antimicrobial agent to prevent the visible growth of microorganisms (bacteria). MIC is used to evaluate the antimicrobial efficacy of various antimicrobial compounds. This is done by measuring the effect of decreasing concentrations of antimicrobial agents in terms of inhibition of microbial population over a defined period. MIC is usually a diagnostic tool in microbiology laboratories to confirm resistance. MIC is the first step in drug discovery processes that are performed for bacteria of interest. MIC is also the starting point for larger preclinical evaluations of new antimicrobial drugs.
The test result of MIC is expressed in micrograms per millilitre (μg/mL) or milligrams per liter (mg/L). The results are normally graded as susceptible, increased exposure, or resistant to a particular antimicrobial agent. Furthermore, when the MIC value is closer to the MIB value, the antimicrobial agent is determined to be more bactericidal. In addition, the aim of MIC is to ensure antimicrobial agents such as antibiotics are chosen efficiently to increase the success of the treatment regime.
What are the Similarities Between MBC and MIC?
- MBC and MIC are two microbiological tests used to evaluate germ killing activity of antimicrobial agents.
- These tests evaluate antimicrobial agents for their efficacy.
- These tests are important steps in routine drug discovery.
- Both these tests are extremely important while manufacturing new antimicrobial drugs and are performed by qualified microbiologists.
What is the Difference Between MBC and MIC?
MBC or minimum bactericidal concentration is the lowest concentration of antimicrobial agent that will prevent the growth of an organism after subculture onto a media containing no antibiotics, while MIC or minimum inhibitory concentration is the lowest concentration of an antimicrobial agent that will inhibit the visible in vitro growth of a microorganism after overnight incubation. Thus, this is the key difference between MBC and MIC. Furthermore, MBC displays the lowest level of antimicrobial agent, resulting in microbial death, whereas MIC displays the lowest level of antimicrobial agent that greatly inhibits microbial growth.
The below infographic presents the differences between MBC and MIC in tabular form for side-by-side comparison.
Summary – MBC vs MIC
MBC and MIC are two microbiological tests used to evaluate germ killing activity of antimicrobial agents. MBC or minimum bactericidal concentration is the lowest concentration of antimicrobial agent that will prevent the growth of an organism after subculture onto a media containing no antibiotics. On the other hand, MIC or minimum inhibitory concentration is the lowest concentration of an antimicrobial agent that will inhibit the visible in vitro growth of a microorganism after overnight incubation. So, this is the key difference between MBC and MIC.
Reference:
1. Tanner, Ben. “Minimum Bactericidal Concentration (MBC) Test.” Microchem Laboratory, 26 Nov. 2021.
2. “Minimum Inhibitory Concentration.” An Overview | ScienceDirect Topics.
Image Courtesy:
1. “Pseudomonas aeruginosa antibiotic susceptibility testing” By HansN. – Own work (CC BY-SA 4.0) via Commons Wikimedia