In vitro paradoxical growth of Pythium insidiosum in the presence of caspofungin

Vet Microbiol. 2010 Oct 26;145(3-4):321-3. doi: 10.1016/j.vetmic.2010.04.001. Epub 2010 Apr 14.


Pythium insidiosum is a zoosporic organism which causes pythiosis in humans and animals. This study aimed to report the paradoxical growth of Brazilian P. insidiosum strains when submitted to in vitro susceptibility tests with caspofungin. The growth at concentrations above the minimal inhibitory concentration (MIC) ranged from 16 to 128 μg/ml and it was observed in 50% of the isolates tested. This paradoxical growth in the presence of caspofungin has been observed with Candida and Aspergillus strains, however, the phenomenon involving oomycetes was described here for the first time.

MeSH terms

  • Animals
  • Antifungal Agents / pharmacology*
  • Brazil
  • Caspofungin
  • Echinocandins / pharmacology*
  • Horse Diseases / drug therapy
  • Horse Diseases / microbiology*
  • Horses
  • Lipopeptides
  • Microbial Sensitivity Tests / veterinary
  • Pythiosis / drug therapy
  • Pythiosis / microbiology
  • Pythiosis / veterinary*
  • Pythium / drug effects*
  • Pythium / growth & development


  • Antifungal Agents
  • Echinocandins
  • Lipopeptides
  • Caspofungin