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


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 10864 for another view of this culture under a magnification of approximately 10X.

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 (6.68 MB)
Content Providers(s):CDC/ Dr. Richard Facklam
Creation Date:2008
Photo Credit:
CDC Organization
Skip Navigation Links.

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.