The lipid compositions of two isolates of Cladosporium cucumerinum do not explain their differences in sensitivity to fungicides which inhibit sterol biosynthesis

Abstract

Isolate 840905 of Cladosporium cucumerinum, when grown on agar or in liqiud medium, was sensitive to triadimenol, H W G 1608 (tebuconazole), fenpropimorph and pimaricin but relatively resistant to terbinajine. Conversely, isolate 49628 was sensitive to terbinajine but relatively resistant to the other fungicides. Changes in sterol composition following treatment with the fungicides reflected the known modes of action of each fungicide. When individual enantiomers of triadimenol were tested against isolate 840905 the order of activity in reducing mycelial growth was 1 S J R > 1 R,2R > 1 R J S 2: 1 S J S , and this was paralleled by the depletion of ergosterol and the appearance of 14a-methyl sterols. Isolate 49628 had a greater saturated:unsaturated fatty acid ratio than did isolate 840905 but no major changes in fatty acid composition of either isolate were induced by fungicide treatment. There appears to be no obvious explanation for the differences in fungicide sensitivity of the isolates in terms of their lipid compositions.

Allylamine Antifungal Drugs

“…In addition to its effects on human and animal pathogens, terbinafine has also been reported to inhibit several fungi of agricultural importance as plant pathogens. [42][43][44][45] Activity of the allylamines against yeasts is quite variable between different species and strains. For example, Candida parapsilosis is very susceptible whereas C. glabrata shows little response (Table 6-2).…”