In vitro susceptibility of Pythium insidiosum to garlic extract

Abstract

Pythium insidiosum infections are difficult to treat with conventional antifungal agents because of the lack
of ergosterol in the cytoplasmic membrane of this aquatic oomycete. The effectiveness of the garlic
compound allicin has been demonstrated against a range of bacteria, fungi and plant oomycetes.
Therefore, we evaluated the in vitro activity of Allium sativum extract against 17 clinical isolates of P.
insidiosum. The assays were performed according to M38-A2 Clinical Laboratory and Standards Institute
documents. Minimum inhibitory concentrations varied from <0.39 to 6.25 mg ml-1
. The results showed that
garlic extract has strong inhibitory activity toward P. insidiosum isolates in vitro. By understanding the
cons of extrapolating in vitro data to clinical studies, A. sativum seems to offer a promising alternative in
the treatment of pythiosis infections in humans and animals.