After 24 hours of growth, this image depicts four different agar media culture plates that had been inoculated with Shigella sp., Escherichia sp., and Proteus sp. bacteria, (clockwise: MacConkey, Shigella-Salmonella, Bismuth Sulfite, and Brilliant Green agars).

Differences in the constituents, which compose the various agar media, are used as determinants as to which bacteria are fostered on each culture plate. Thriving culture colonies on one type of medium may not thrive on another type of medium based on the agars’ ingredients, which a given bacterium will require to maintain life.

Image source: Centers for Disease Control and Prevention Publich Health Image Library.

本圖像是美國衛生及公共服務部所屬的美國疾病控制與預防中心的員工在職務期間所拍攝或繪製的。作為美國聯邦政府的作品，本圖片屬於公有領域。