Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content

Heading


ID#:16940
Description:Caption:
This set of three Petri dish culture plates contained a Mueller-Hinton agar growth medium that had been inoculated with a culture composed of Staphylococcus sp. bacteria. Atop the growth medium, antibiotic-impregnated disks had been laid, which gave rise to this example of an antibiotic sensitivity test. The three plates were kept, clockwise, at a respective pH 8.0, pH 6.5, and pH 7.2. As you can see, the pH of the agar had a measurable impact on the growth of these bacteria.
Additional Information:
The size of the inhibition zones (IZ) surrounding the antibiotic-impregnated paper disks depends on the sensitivity of the bacteria present in the agar, to the antibiotic, the antibiotic's ability to diffuse through the culture medium, and the pH of the medium. In this case, the results were as follows:

- Tetracycline Disks (TE) produced an IZ of 18mm/pH 8.0; 27mm/pH 6.5; 22mm/pH 7.2

- Lincomycin Disks (L) produced an IZ of 23mm/pH 8.0; 12mm/pH 6.5; 18mm/pH7.2

- Streptomycin Disks (S) produced an IZ of 23mm/pH 8.0; 16mm/pH 6.5; 20mm/pH 7.2

- Erythromycin Disks (E) produced an IZ of 32mm/pH 8.0; 23mm/pH 6.5; 27mm/pH 7.2.

High Resolution: Click here for hi-resolution image (18.35 MB)
Content Providers(s):CDC
Creation Date:1971
Photo Credit:
Links:
Categories:
CDC Organization
Skip Navigation Links.

MeSH
Skip Navigation Links.
Copyright Restrictions:None - This image is in the public domain and thus free of any copyright restrictions. As a matter of courtesy we request that the content provider be credited and notified in any public or private usage of this image.

TOP