Minimum Bactericidal Concentration (MBC) Test

Summary of Minimum Bactericidal Concentration (MBC) Test

The minimum bactericidal concentration (MBC) is the minimum concentration of antibacterial agents required to kill bacteria under a set of specific conditions. It refers to the minimum concentration of an antimicrobial agent that causes a 3-logarithmic decrease (99.9% killing) in the size of the standard inoculum.

MBC is carried out after the minimum inhibitory concentration (MIC) test and is a supplement to MIC. It should be noted that the MIC test showed the lowest level of antimicrobial agent that greatly inhibits growth, while MBC demonstrates the lowest level of antimicrobial agent caused the death of microorganisms. In general, if the MBC does not exceed four times the MIC, the antibacterial agents are regarded as bactericidal/fungicidal. MBC is considered to be a good and cheap tool that can simultaneously evaluate the bactericidal activity of multiple antibacterial agents. 

Figure 1. Minimum inhibitory concentration (MIC) versus minimum bactericidal concentration (MBC) (Karaman, D.S.; et al. 2017)

Experimental Steps of MBC Test Provided by Creative BioMart Microbe

Overnight culture of a specific microorganism, then diluted in Mueller Hinton Broth to a concentration between 1 x 105 and 1 x 106 cfu/ml.

Prepare test compounds at 2-fold serial dilutions.

Prepare a positive and negative control tube or well for every test microorganism.

Incubate the test tubes or microtiter plates at an appropriate temperature and time to observe the turbidity and judge the growth of microorganisms.

The dilution representing the MIC and at least two of the more concentrated test product dilutions are plated and enumerated to determine viable CFU/ml.

Advantages of the Minimum Bactericidal Concentration (MBC) Test

• The MBC test can test various antibacterial agents at the same time for screening purposes.
• The MBC test can be used to evaluate formulation problems.
• The MBC test is easy to operate, and the parameters are easy to control.

Disadvantages of the Minimum Bactericidal Concentration (MBC) Test

• More nutritious growth media will negatively affect the MBC value. Mueller Hinton Broth is the most recommended broth for this method.
• The MBC of each microorganism must be determined individually. Antimicrobial agents for different tested microorganisms may have different MBC values.
• MBC test results cannot determine the concentration of antimicrobial agent needed to disinfect or sanitize microorganisms within a short contact time (for example, 10 minutes).

Creative BioMart Microbe provides customers with high-quality minimum inhibitory concentration (MIC) test and minimum bactericidal concentration (MBC) test. We have formed a professional team of microbiology experts, introduced an advanced technology platform, and accumulated a lot of experience, aiming to help customers solve all the problems encountered in the research of microbiology. 

If you want to know more about this service, please feel free to contact us by phone or email, or you can consult through our inquiry form. We will ensure to provide you with efficient and high-quality experimental outsourcing services.

Reference

1. Karaman, D.S.; et al. Current Approaches for Exploration of Nanoparticles as Antibacterial Agents. Antibacterial Agents. 2017.