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Under an approximate 10X magnification, this image depicts the colonial characteristics displayed by Streptococcus pneumoniae bacterial colonies that were grown on primary isolation medium, consisting of trypticase-soy-agar, containing 5% sheep’s blood, as well as 5mg of gentamicin/ml. See PHIL 10863 for another view of this culture.

The S. pneumoniae bacterial inoculum were harvested from a primary nasopharyngeal, i.e., throat swab. The culture plate was stored under modified atmospheric conditions by using a candle-extinction jar, thereby, bringing about an approximate 3% increase in carbon dioxide.

Note that the so called doughnut-shaped colonies are those of Streptococcus pneumoniae. Those that do not have depressed centers are not S. pneumoniae.

High Resolution: Click here for hi-resolution image (6.69 MB)
Content Providers(s):CDC/ Dr. Richard Facklam
Creation Date:2008
Photo Credit:
CDC Organization
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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.