Prototheca zopfii
(Krüger, 1890)



  • yeast like colonies, smooth surface and  smooth margin

  • beige or ocher colored.

  • Micro morphology: round single cells (3-15 µm in diameter) and
    some large Sporangiospores with round endospores inside (10-30 µm).



  • plate culture on fungi media, e.g. Sabouraud-glucose-agar, Kimmig-agar

  • subsequent microscopical examination of smears with lactophenole cotton blue 
    or with PAS-staining or Immunofluoreszence (pathohistology)

  • Differentiation between P. zopfii and P. wickerhamii by assimilation of Trehalose.
    P. wickerhamii utilize trehalose; P. zopfii does not.

  • Differentiation of two Genotypes (Biotypes, Serotypes)  

  • Bovine Prototheca mastitis: indirect ELISA with whey



Human protothecosis

  • only in exceptional cases, usually caused by P. wickerhamii

  • cutaneous form and  systemical form

Canine protothecosis

  • just as frequent as P. zwickerhamii

  • cutaneous form and systemical form

Bovine protothecosis 

  • most frequent infection due to heterotrophic algae



  • facultative pathogen

  • predisponating factors, e.g. immunosupression and high lactation


Immune response

  • induction of specific systemic and lokal antibodies of immunglobuline
    isotypes G and A

  • high resistance to phagozytosis 

  • Persistence and proliferation within macrophages and PMN's