MICROBIOLOGY

• Members of genus Prototheca, an achlorophyllic green algae.
  • The genus is now included within the class Trebouxiophyceae, order Chlorellales, and family Chlorellaceae
  • Prototheca wickerhamii is the most frequently isolated.
    • Other species reported: P. zopfii is the second most commonly isolated, followed distantly by P. cutis and P. miyajii.
    • P. wickerhamii appears with more symmetrical and smaller morula and sporangia than P. zopfii
  • Present in water, soil and decomposing matter.
  • It may be found in flora and excrement of multiple mammals, especially cattle and dogs.
• It may behave like slow-growing yeast in the micro lab.
  • Growth may be achieved on chocolate agar, Sabouraud dextrose agar or sheep blood agar.
  • Colonial growth appears dull-white [Fig 1].