In vitro assays on the susceptibility of four species of nematophagous fungi to anthelmintics and chemical fungicides/antifungal drug

Using nematophagous fungi for the biological control of animal parasitic nematodes will become one of the most promising strategies in the search for alternative chemical drugs. The purpose of this study was to check the in vitro activity of four anthelmintics, four chemical fungicides and two antifungal drugs on the spore germination of nematophagous fungi: Duddingtonia flagrans (SF170), Arthrobotrys oligospora (447), Arthrobotrys superba (435) and Arthrobotrys sp. (PS011). A modified 24-well cell culture plate assay was conducted to evaluate the susceptibility of nematophagous fungi against drugs tested by calculating the effective middle concentrations (EC50) of each tested drug to inhibit the germination of fungal spores. EC50 ranged between 0 center dot 7 and 47 center dot 2 mu g ml(-1) for fenbendazole, thiabendazole and ivermectin, except levamisole (546 center dot 5-4057 center dot 8 mu g ml(-1)). EC50 of tested fungicides was 0 center dot 6-2 center dot 3 mu g ml(-1) for carbendazim, 55 center dot 9-247 center dot 4 mu g ml(-1) for metalaxyl, 24 center dot 4-45 center dot 2 mu g ml(-1) for difenoconazole, and 555 center dot 9-1438 center dot 3 mu g ml(-1) for pentachloronitrobenzene (PCNB). EC50 of two antifungal drugs was 0 center dot 03-3 center dot 4 mu g ml(-1) for amphotericin B and 0 center dot 3-10 center dot 9 mu g ml(-1) for ketoconazole. The results showed that 10 tested drugs, except for levamisole and PCNB, had in vitro inhibitory effects on nematophagous fungi. The chlamydospores of D. flagrans had the highest sensitivity to nine tested drugs, except for ketoconazole.

Automated summary

The study aimed to evaluate the in vitro activity of different drugs on the spore germination of nematophagous fungi, and the results showed that 10 tested drugs had inhibitory effects on the fungi.