Difference between MIC and MBC in microbiology

 

 Difference between MIC and MBC in microbiology

  THE MIC (Minimum Inhibitory Concentration)

   Is the lowest bacteriostatic concentration of an antibiotic component or agent (preventsthe visible growth of bacteria).MICs are used to assess the antimicrobial activity of various compounds by determining the effect of decreasing antibiotic/antiseptic concentrations over time on microbial population growth inhibition. Because the concentration of drug required to generate the effect is typically hundreds to thousands of times lower than the concentration found in the finished dosage form, these studies can be highly valuable for determining appropriate concentrations required in the final product.The chemicals are inoculated with cultivated bacteria at various doses, and the results are analyzed using agar dilution or broth dilution (macro or micro) to obtain the MIC endpoint. Susceptibility testing is usually done with organisms that are involved in an infectious process that requires antibiotic treatment.

The ESKAPE pathogens are a regularly utilized bacterium cocktail (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). The ESKAPE pathogens are known to be resistant to antimicrobials and are the major cause of nosocomial (hospital-related) infections.

her species, such as aerobic or anaerobic bacteria, yeasts, or filamentous fungus, can also be used, either singly or in various combinations.

The Minimum Bactericidal Concentration (MBC) 

 This is the lowest antibacterial concentration requirewd to kill a bacterium over a specified, some lengthy period of time, such as 18 hours or 24 hours, under certain conditions.

Subculturing to agar plates that do not contain the test agent can be inferred from the broth dilution of MIC testing. The MBC is found by finding the lowest concentration of antibacterial agent that reduces the viability of the initial bacterial inoculum by a predetermined percentage, such as 99.9%. Unlike the MIC test, which shows the lowest amount of antimicrobial agent that significantly slows growth, the MBC test shows the lowest level of antimicrobial agent that results in microbial death. To put it another way,Because the antibiotic did not cause death, plating the bacteria onto agar may result in organism expansion even if the MIC indicated inhibition. If the MBC is less than four times the MIC, antibacterial agents are considered bactericidal.

MBC testing 

This can be a useful and reasonably inexpensive approach for evaluating the potency of numerous antimicrobial drugs at the same time. When the formulator suspects that the active ingredient is being "bound up" by other substances, the MBC test can be used to examine the problem. The theory is that a product with a portion of its active ingredient chemically mixed with other substances will have a higher MBC because the active ingredient will not be available to kill microorganisms in suspension.