MIC in liquid medium

☰ Summary :

Ⅰ. Definition

In liquid medium, bacterial growth is visualized by a bacterial disorder.

MIC (minimum inhibitory concentration) : the lowest concentration of antibiotic inhibiting the visible growth of a given strain.

Ⅱ. Liquid medium

Mueller-Hinton (MH) broth, adjusted for divalent cations, is used in the liquid dilution method (micro-dilution) for non-demanding bacteria.

MH-F broth, MH broth supplemented with 5% lysed horse blood and 20 mg / L β-NAD, is used for Streptococcus spp., Including Streptococcus pneumoniae, Haemophilus spp., Moraxella catarrhalis, Listeria monocytogenes, Campylobacter spp. ., Pasteurella sp., Corynebacterium sp. and other slow growing bacteria.

Ⅲ. Operating mode

  • A range of antibiotic (X) of decreasing concentrations is made by successive dilutions of 1/2 ratio from a stock solution of the antibiotic.
  • A series is prepared with the same volume of the liquid culture medium.
  • The same amount of germs are added to each tube (inoculum).
  • The prepared tubes are incubated at 37 ° C for 18 hours.
  • They are examined with the naked eye.

MIC in liquid medium

MIC in liquid medium

Conclusion : The higher the concentration required, the higher the MIC and the less sensitive the germ.