Details - Public Health Image Library(PHIL)

ID#:

8180

Caption:

Magnified 100x, this 1977 photograph depicted a Petri dish filled with trypticase soy agar medium containing 5% defibrinated sheep's blood. After having been inoculated with alpha-hemolytic, Streptococcus anginosus bacteria, a member of the Gram-positive viridans group of streptococci (VGS), just before the blood was added to the agar, a loop of diluted culture was put into the melted agar (50^oC). The melted agar with blood was allowed to solidify and then incubated at 35^oC for 24 hours in a normal atmosphere. The culture grew subsurface bacterial colonies, one of which was seen here, surrounded by a characteristic hazy, faded, and indistinct region (arrow), in which only some of the red blood cells (RBCs) were destroyed, or hemolyzed, in the agar, indicating that these bacteria were alpha-hemolytic in nature.

High Resolution:

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Content Provider(s):

CDC/ Richard R. Facklam, Ph.D.

Creation Date:

1977

Photo Credit:

Links:

Categories:

CDC Organization