Mueller-Hinton agar plate

Note 2 Fungi spores from an active culture were suspended in 1 ml sterile 0.85 NaCl, then lawned on 150 mm Mueller-Hinton agar plates with a sterile cotton swab... 

Micrococcus luteus (ATCC 9341) Assay. Mueller-Hinton agar plates were overlayed with 0.7% Difco Bacto-agar containing approximately 2.5 x 10 cells of M. luteus/ml. When the agar is set, 15 yl of... 

In the morning, BHI (brains-heart infusion) nutrient broth was inoculated with bacteria, from an overnight culture or agar, to be used within 4 h. Within that incubation time, Mueller-Hinton (MH) plates were allowed to reach room temperature. 

The determination of MIC of antibiotics was performed by microtiter method. Antimicrobial agents were diluted by serial dilutions MPB in flat-bottomed plates, they were also added to the culture of Staphylococcus aureus, and were incubated for 24 hr at 34°C. The control was culture Staphylococcus aureus without antimicrobial agents. After that mixture sowed on solid nutrient medium Mueller-Hinton agar for calculation of amount of colony forming particles and MIC definitions. The MIC was considered to be the lowest concentration, which retards the growth of Staphylococcus aureus during the incubation period. 

Reagents and materials Antibiotics, Ampicillin, Mueller Hinton Agar, agar plates were purchased from Meditron Scientific Limited. Bacterial and fimgal cultures were obtained from the Georgetown Public hospital, GPHC. 

The bacterium is grown on blood agar plates and stored in a mixture of Mueller-Hinton broth containing 20% (v/v) glycerol. In this mixture, bacteria can be stored in small aliquots for several years at -70°C. 

If larger culture volumes are required then 2.5-L Ehrlenmeyer flasks containing a maximum of one liter of Mueller-Hinton broth are prepared and autoclaved. Once cooled, this broth may be seeded directly with colonies from the agar plate however, this often results in poor yields and slow growth. It is better to seed this volume of culture with a small amount of overnight broth culture. 

To prepare a seeding culture, fill a 25 pL universal with approximately 10 pL of sterile Mueller-Hinton broth and seed these with 1-2 colonies from the blood agar plate. This is then incubated at 37°C overnight with vigorous shaking at approximately 200 rpm. 

The historical gradient plates, ditch-plate and cup-plate techniques (see Hugo 8c Russell, 1998) have been replaced by more quantitative techniques such as disc diffusion (Fig. 11.4), broth and agar dilution, and E-tests (Fig. 11.5). All employ chemically defined media (e.g. Mueller-Hinton or Iso-Sensitest) at a pH of 7.1—1 A, and in the case of solid media, agar plates of defined thickness. 

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