Minimum inhibitory concentration

Minimum inhibitory concentration


  • [3]

External links

  1. ^ a b Andrews, J. M. (1 July 2001). "Determination of minimum inhibitory concentrations".  
  2. ^ Turnidge JD, Ferraro MJ, Jorgensen JH (2003) Susceptibility Test Methods: General Considerations. In PR Murray, EJ Baron, JH Jorgensen, MA Pfaller, RH Yolken. Manual of Clinical Microbiology. 8th Ed. Washington. American Society of Clinical Microbiology. p 1103 ISBN 1-55581-255-4
  3. ^ Davison, HC; Low, JC; Woolhouse, ME (December 2000). "What is antibiotic resistance and how can we measure it?".  
  4. ^ O'Neill, AJ; Chopra, I (August 2004). "Preclinical evaluation of novel antibacterial agents by microbiological and molecular techniques.".  


  • Bacteriostatic agent Rule of thumb the less the number(concentration) it gives better coverage.
  • MBC (Minimum Bactericidal Concentration)

See also

Clinically, the minimum inhibitory concentrations are used not only to determine the amount of antibiotic that the patient will receive but also the type of antibiotic used, which in turn lowers the opportunity for microbial resistance to specific antimicrobial agents. Applying MIC testing to a number of bacterial strains in the same species provides an estimate of the concentration that inhibits 50% (MIC50) and 90% (MIC90) of bacterial isolates and can indicate shifts in the susceptibility of bacterial populations to antibiotics,[3] MICs are therefore often the starting point for larger preclinical evaluations of novel antimicrobial agents.[4] Currently, there are a few web-based, freely accessible MIC databases.

Clinical significance

The Etest system comprises a predefined and continuous concentration gradient of different antimicrobial agents, which when applied to inoculated agar plates and incubated, create ellipses of microbial inhibition.[1] The MIC is determined where the ellipse of inhibition intersects the strip, and is easily read off the MIC reading scale on the strip.[2]

MICs can be determined by agar dilution or broth microdilution, usually following the guidelines of a reference body such as the CLSI, BSAC or EUCAST. There are several commercial methods available, including the well established Etest strips and the recently launched Oxoid MIC Evaluator method.

  1. Preparation of antibiotic stock solution
  2. Preparation of antibiotic dilution range
  3. Preparation of agar dilution plates
  4. Preparation of inoculum
  5. Inoculation
  6. Incubation
  7. Reading and interpreting results

MIC of an antibiotic is determined by using the following procedure:[1]



  • Determination 1
  • Clinical significance 2
  • See also 3
  • References 4
  • External links 5