Effects of iprodione and fludioxonil on glycerol synthesis and hyphal development in Candida albicans.
We investigated the effects of iprodione and fludioxonil on the pathogenic yeast Candida albicans. Growth of the wild-type IFO1385 strain of C. albicans was inhibited by both fungicides, while Saccharomyces cerevisiae was basically unaffected by them even at a concentration of 25 microg/ml. Both fungicides stimulated glycerol synthesis in C. albicans but not in S. cerevisiae. The antioxidant alpha-tocopherol acetate and the cytochrome P-450 inhibitor piperonyl butoxide antagonized the fungitoxicity of iprodione and fludioxonil in C. albicans. It is known that mutations within the histidine kinase NIK1/OS-1 gene confer resistance to iprodione and fludioxonil in Neurospora crassa, while the fungicide-insensitive S. cerevisiae has only one histidine kinase SLN1 gene in its genome. In contrast, C. albicans has three histidine kinase genes, namely CaSLN1, CaNIK1/COS1, and CaHK1, the null mutants of which were found to impair the hyphal formation. Iprodione and fludioxonil were found to suppress filamentation when the IFO1385 strain was incubated on a solid medium containing fetal bovine serum. These observations suggest that iprodione and fludioxonil interfere with the CaNIK1/COS1 signal transduction pathway, resulting in glycerol synthesis stimulation and the inhibition of hyphal formation.
Ochiai
Noriyuki
N
Faculty of Life Science, University of Toyo, Itakura, Oura-gun 374-0193, Japan.
Fujimura
Makoto
M
Oshima
Michiyo
M
Motoyama
Takayuki
T
Ichiishi
Akihiko
A
Yamada-Okabe
Hisafumi
H
Yamaguchi
Isamu
I
D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development* / Q000648:ultrastructure; D003470:Culture Media; D004149:Dioxoles / Q000494:pharmacology*; D005659:Fungicides, Industrial / Q000494:pharmacology*; D005990:Glycerol / Q000378:metabolism; D000071677:Histidine Kinase; D006827:Hydantoins; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D010574:Pesticide Synergists / Q000494:pharmacology; D010882:Piperonyl Butoxide / Q000494:pharmacology; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics; D011758:Pyrroles / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D014810:Vitamin E / Q000494:pharmacology
D000975:Antioxidants; D003470:Culture Media; D004149:Dioxoles; D005659:Fungicides, Industrial; D006827:Hydantoins; D010574:Pesticide Synergists; D011758:Pyrroles; D014810:Vitamin E; D000620:Aminoimidazole Carboxamide; D011494:Protein Kinases; D000071677:Histidine Kinase; C108339:fludioxonil; D010882:Piperonyl Butoxide; D005990:Glycerol; C033148:iprodione