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[Preservation of margarine in fungicidal paper].

The authors studied the effect of a new type of package material, fungicide paper with one side coated with sorbic acid (fungicide) at a rate of 0.08 g per square decimeter of the surface and other side coated with water- and gas-proof polymer film 60 to 80 microns thick, on the quality of margarine of storage. It was established that by the end of storage the surface of margarine samples packed in parchment and fungicide paper did not exhibit any mold. At the same time, however, the processes of oxidation and formation of the stuff layer were most pronounced in margarine packed in parchment. The amount of the stuff layer in margarine increased toward the end of storage, amounting to 6.63% in margarine packed in parchment and to 5.16% in that packed in fungicide paper.

Chemical Phenomena↗
PubMed1995

[The breakdown of the fungicide carbendazim in an aqueous environment].

The study of the breakdown of the fungicide carbendazim widely used in Poland was carried out under model conditions simulating the environment of river water moderately polluted, distilled water, and dynamic aqueous ecosystem. The experiments were conducted using the fungicide in concentrations about 1 and 5 mcg/l at two temperatures-about 20 degrees C and 5 degrees C, and after adaptation of microorganisms to the presence of the fungicide. Taking the results of the experiment with river water the rate of the breakdown was studied, determining also the kinetic parameters of the breakdown process: rate constants and half-times of breakdown. This process agreed, as a rule, with the kinetic equation of first order and depended on the type of water, initial concentration, temperature and microflora adaptation to the environment of the tested substance. The process of carbendazime breakdown after adaptation of the microorganisms of river water to the fungicide was occurring at a much higher rate at both test temperature and depended on the initial concentration. Temperature decrease to about 5 degrees C inhibited the process of carbendazime degradation, but only if the initial concentration was higher. The concentrations of carbendazime in aqueous environment under dynamic conditions during 14-day exposure decreased by 14-19% and had no negative influence on the biocenosis of the experimental ecosystem Carbendazime was not taken up by water-thyme and Lebistes reticulata in the experimental ecosystem, was poorly concentrated by snails and accumulated slightly in the sediments of the ecosystem.

Animals↗
PubMed1987

Combined application of low temperature preparation and electron microscopic autoradiography for the localization of systemic fungicides.

The intracellular localization of the sterol-biosynthesis-inhibiting (SBI) fungicide (3H)triadimenol A is investigated in vitro in the fungus Ustilago avenae. For this purpose low temperature preparation techniques (shock freezing, freeze substitution, embedding in Lowicryl HM20) are combined with conventional electron microscopic (EM) autoradiography. In particular the suitability of Lowicryl HM20 embedded specimens for EM autoradiography with regard to the finestructure preservation is shown. For the localization of (3H)triadimenol the filamentous grain development as well as the application of the gold latensification method resulting in the appearance of spherical silver grains is tested. Fungicide sensitive wild type sporidia of U. avenae are compared with fungicide resistant cells of the mutant r8. A quantitative analysis of the autoradiographs of the wild type developed according to the gold latensification process shows a relatively homogeneous distribution of silver grains over the entire cell. On the other hand, the resistant mutant is characterized by an accumulation of silver deposits over the vacuoles as compared with the lower density of grains over the cell walls and cytoplasm. The data are discussed in the context of possible resistance mechanisms against SBI-fungicides.

Autoradiography↗
PubMed1994

Iturin A: a potential new fungicide for stored grains.

The removal of many synthetic fungicides from the market has created a demand for new, environmentally safe fungicides. Iturin A, a cyclic lipopeptide produced by Bacillus subtilis, has strong antifungal properties and low mammalian toxicity. To determine the efficacy of this compound as a potential fungicide on stored feed grains, lots of corn, peanuts and cottonseed were treated with varying concentrations of iturin A. The mycoflora of treated seed was assayed along with that of untreated seed and seed treated with fungicides used commercially for planting seed. Fungal species varied considerably in their sensitivity to iturin A. Significant reductions in total mycoflora occurred in most seed lots tested at iturin A concentrations of 50 to 100 ppm.

Anti-Bacterial Agents↗
PubMed2003

Fungicidal effect of indolicidin and its interaction with phospholipid membranes.

The fungicidal effect and mechanism of a tryptophan-rich 13-mer peptide, indolicidin derived from granules of bovine neutrophils, were investigated. Indolicidin displayed a strong fungicidal activity against various fungi. In order to understand the fungicidal mechanism(s) of indolicidin, we examined the interaction of indolicidin with the pathogenic fungus Trichosporon beigelii. Fluorescence confocal microscopy and flow cytometry analysis revealed that indolicidin acted rapidly on the plasma membrane of the fungal cells in an energy-independent manner. This interaction is also dependent on the ionic environment. Furthermore, indolicidin caused significant morphological changes when tested for the membrane disrupting activity using liposomes (phosphatidylcholine/cholesterol; 10:1, w/w). The results suggest that indolicidin may exert its fungicidal activity by disrupting the structure of cell membranes, via direct interaction with the lipid bilayers, in a salt-dependent and energy-independent manner.

Amino Acid Sequence↗
PubMed1986

A simple physical model for fungicide induced hexagonal clustering of intramembrane particles in the plasmalemma of Ustilago avenae.

Freeze fracture electron microscopy is used to study the influence of fungicide (triadimenol) treatment on the plasmalemma of sporidia of Ustilago avenae. The intramembrane particles (IMPs) randomly distributed in untreated samples form large hexagonal clusters after triadimenol treatment. A simple physical model based on length mismatch between lipid bilayer and IMPs is used to describe the interaction between the IMPs in terms of a lipid mediated potential. Using for a rough estimation also data on artificial membranes the fungicide induced ordering effect of the IMPs is discussed. A homogeneous change of lipid bilayer parameters due to the fungicide action is considered as well as a fluid-gel phase transition of the lipid matrix, which might be related to the cluster formation. Further implications of the different possibilities with respect to the mode of action of the fungicide are suggested.

Antifungal Agents↗
PubMed1978

On the mechanisms of induced somatic recombination by certain fungicides in Aspergillus nidulans.

Four fungicides interfered with the segregation of chromosomes at mitosis of Aspergillus nidulans by increasing the somatic recombination, shown as colour sectors in green colonies, in a strain heterozygous for spore colour mutations. In an attempt to discover the mechanisms by which these fungicides increased the somatic recombination, a prototrophic diploid strain, heterozygous for colour and several other appropriate markers in all chromosomes, was used which enabled the detection and classification of all colour recombinants to be made by genetic analysis. The fungicides investigated were: benomyl (methyl-1-(butylcarbamoyl)-2-benzimidazole carbamate) a benzimidazole derivative, botran (2,6-dichloro-4-nitroaniline) and chloroneb (1,4-dichloro-2,5-dimethoxybenzene) of the aromatic hydrocarbon group of fungicides, and the antibiotic actinomycin D. At least three different mechanisms, non-disjunction, mitotic crossing-over and breakage-deletion, were found to be responsible for the recombinogenic activity of the compounds studied.

Aniline Compounds↗
PubMed2000

Fungicides cytotoxicity expressed in male gametophyte development in Brassica campestris after in vitro application of converted field doses.

A simple method to determine the toxicity of fungicides on male gametophyte in Brassica campestris subsp. oleiferae is described. The calculation of fungicide concentration used in the test is derived from doses used in field application. The expression of regression curves and calculation of regression equations require the logarithmic transformation of fungicide concentration. The range of the sensitivity of the method is very wide. The minimal concentration detected as significantly different from control ranges from 1.7 to 7.0 pg of the active compound. Fungicides declared as non-toxic for plants in field tests were cytotoxic for male gametophyte development. The synergistic action of more than one active compound resulted in higher toxicity.

Journal Article↗
PubMed2004

Potentiation of fungicidal activities of trans-anethole against Saccharomyces cerevisiae under hypoxic conditions.

A naturally occurring phenylpropanoid, trans-anethole (anethole), was assayed for its fungicidal activity in Saccharomyces cerevisiae grown under hypoxic and aerobic conditions. Anethole killed the growing cells in malt extract broth only under hypoxic conditions. Anethole did not exhibit fungicidal effects against non-growing cells. The cells of a mitochondrial-DNA-lacking rho0 mutant, which grew fermentatively even in the presence of O2, were killed by anethole regardless of aeration. The fungicidal potency of anethole against a strain capable of respiration under aerobic conditions was enhanced by the addition of a respiratory inhibitor antimycin A3. Therefore, anethole possibly expresses fungicidal activities only against fermentatively growing cells of S. cerevisiae.

Journal Article↗
PubMed2000

Mechanisms of the in vitro fungicidal effects of human neutrophils against Penicillium marneffei induced by granulocyte-macrophage colony-stimulating factor (GM-CSF).

We examined the in vitro fungicidal activity of human neutrophils against conidia and yeast cells of Penicillium marneffei. Neutrophils showed a small but significant anti-fungal effect against the yeast form of P. marneffei. Treatment of neutrophils with GM-CSF significantly augmented their anti-fungal activity. In contrast, the conidia form resisted killing even by stimulated neutrophils. Neutrophil fungicidal effect was not inhibited by superoxide dismutase (SOD), while the same treatment significantly suppressed the killing of Candida albicans by GM-CSF-stimulated neutrophils. For effective killing of P. marneffei yeast cells by GM-CSF-stimulated neutrophils, direct contact between the two was essential; interference in such interaction by separation using a 0. 45-microm-pored membrane prevented such an effect. Addition of colchicine attenuated GM-CSF-stimulated neutrophil fungicidal activity in a dose-dependent manner. This effect did not appear to be mediated by interference with neutrophil mobility toward yeast cells, because similar results were obtained when the cultures were set in round-bottomed wells which facilitate their direct contact. Finally, granular extracts derived from unstimulated neutrophils significantly suppressed the growth of microorganisms. Pretreatment of neutrophils with GM-CSF markedly enhanced this effect. The fungicidal activity of granular lysates was strongly, but not completely, reduced by heat treatment. Considered together, our results indicate that GM-CSF-stimulated neutrophils killed the yeast form of P. marneffei present in close proximity, probably in a superoxide anion-independent mechanism, but through exocytosis of granular enzymes which were largely heat-labile.

Antifungal Agents↗
PubMed1992

Elevation of intracellular free calcium levels in sperm in response to long-term feeding of fungicides to mice.

To assess the impact of long-term feeding of fungicides on sperm quality, mice were fed a daily diet containing a mixture of maneb and zineb, at concentrations of 30, 300, and 3000 ppm, respectively. Employing epididymal sperm suspended in a medium permitting in vitro capacitation, the intracellular free Ca2+ concentration, [Ca2+]i, was determined with a fluorescent Ca2+ indicator, Fura-2. Regardless of the fungicide dosages applied, [Ca2+]i was about 50 percent higher in treated animals relative to a value of 123 nM [Ca2+]i in the control group. Fungicide-treated mice were mated to mature, non-treated females; as in the control, the litter sizes were the same. In conclusion, the observed elevation in [Ca2+]i seems to reflect cellular adaptation responses to toxic stress at moderate fungicide doses.

Animals↗
PubMed1999

Comparisons of the effects of fungicidal and fungistatic antifungal agents on the morphogenetic transformation of Candida albicans.

Eleven different antifungal agents were compared, and their ability to inhibit the morphogenetic transformation of Candida albicans was examined together with their ability to inhibit growth, as measured by MIC methodology. The fungicidal potential of each agent was also determined. Of the antifungal agents tested, only amphotericin B, mulundocandin and aculeacin inhibited the transformation at sub-MIC values; all three agents showed fungicidal activity at concentrations close to the MIC. All other agents were fungicidal only at concentrations much higher than the MIC and inhibited the morphogenetic transformation only at concentrations above the MIC. These data suggest that fungicidal antifungal agents are more likely to act by inhibiting the morphogenetic transformation of C. albicans while fungistatic agents are unable to do so and are more likely to block growth by budding.

Antifungal Agents↗
PubMed1999

Involvement of calcium inhibitable binding to the cell wall in the fungicidal activity of CAN-296.

CAN-296 is a heat stable, complex carbohydrate (molecular mass 4300 Da) isolated from the cell wall of the filamentous fungus Mucor rouxii. It possesses potent in-vitro fungicidal activity against a wide spectrum of pathogenic yeasts, including azole-resistant isolates of Candida albicans and Candida glabrata. As a preliminary step in the study of the mode of action of this novel antifungal agent, we investigated the effect of various cations on the antifungal activity as well as the binding of CAN-296 to intact cells and cell-wall fractions of C. albicans. The antifungal activity of CAN-296 was inhibited by low concentrations of calcium, magnesium and lithium and by high concentrations of barium, cobalt and manganese, but not by potassium and copper. The calcium-mediated inhibition of the antifungal activity of CAN-296 was readily reversible by the removal of calcium by dialysis, and the fungicidal activity of the inhibited compound was fully restored. The uptake/binding of CAN-296 to intact cells and to the cell-wall fraction of C. albicans was time and concentration dependent. Maximum uptake/binding was obtained at 5 mg/L within 60 min and was associated with the aggregation of intact cells. Washing intact cells and the cell-wall fraction preincubated with radiolabelled CAN-296 with 150-fold excess of unlabelled compound failed to remove CAN-296 associated with the intact cells and the cell-wall fraction, suggesting that the binding of CAN-296 to C. albicans is tight. The uptake/binding of CAN-296 and the drug-mediated aggregation of intact cells were inhibited by calcium in a concentration-dependent manner. The fact that CAN-296 is a fungicidal agent that binds to intact cells and the cell-wall fraction of C. albicans very tightly, together with the observation that calcium was able to inhibit the fungicidal activity as well as the uptake/binding of CAN-296, suggests that the mode of action of this novel antifungal agent may involve interaction with the cell wall of C. albicans.

Antifungal Agents↗
PubMed2001

The ABC transporter BcatrB affects the sensitivity of Botrytis cinerea to the phytoalexin resveratrol and the fungicide fenpiclonil.

During pathogenesis, fungal pathogens are exposed to a variety of fungitoxic compounds. This may be particularly relevant to Botrytis cinerea, a plant pathogen that has a broad host range and, consequently, is subjected to exposure to many plant defense compounds. In practice, the pathogen is controlled with fungicides belonging to different chemical groups. ATP-binding cassette (ABC) transporters might provide protection against plant defense compounds and fungicides by ATP-driven efflux mechanisms. To test this hypothesis, we cloned BcatrB, an ABC transporter-encoding gene from B. cinerea. This gene encodes a 1,439 amino acid protein with nucleotide binding fold (NBF) and transmembrane (TM) domains in a [NBF-TM6]2 topology. The amino acid sequence has 31 to 67% identity with ABC transporters from various fungi. The expression of BcatrB is up regulated by treatment of B. cinerea germlings with the grapevine phytoalexin resveratrol and the fungicide fenpiclonil. BcatrB replacement mutants are not affected in saprophytic growth on different media but are more sensitive to resveratrol and fenpiclonil than the parental isolate. Furthermore, virulence of deltaBcatrB mutants on grapevine leaves was slightly reduced. These results indicate that BcatrB is a determinant in sensitivity of B. cinerea to plant defense compounds and fungicides.

ATP-Binding Cassette Transporters↗
PubMed1999

Role of superoxide anion in the fungicidal activity of murine peritoneal exudate macrophages against Penicillium marneffei.

Penicillium marneffei is an important opportunistic fungal pathogen. The mechanisms of host defense against P. marneffei are not fully understood. In the present study, we, for the first time, investigated the role of superoxide anion (O2-) in the killing of two forms of P. marneffei, yeast cells and conidia, and the role of this killing mediator in the fungicidal activity of IFN-gamma-stimulated murine peritoneal macrophages. P. marneffei yeast cells were susceptible to the killing effect of activated macrophages and chemically generated O2, while conidia were not. These results suggested that O2- played some role in the fungicidal activity of macrophages. However, an oxygen radical scavenger, superoxide dismutase (SOD), did not suppress, but rather enhanced the fungicidal activity of IFN-gamma-stimulated macrophages against P. marneffei yeast cells. This inconsistency was explained by the release of insufficient concentrations of O2- by activated macrophages as compared with the amount of O2- necessary for the killing of yeast cells, which was predicted in a chemical generating system. On the other hand, SOD enhanced the production of nitric oxide (NO) by IFN-gamma-activated macrophages, and their increased fungicidal activity was significantly inhibited by N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of NO synthase. Our results suggested that O2- does not function as the killing mediator of macrophages against P. marneffei, but rather plays an important role in the regulation of the NO-mediated killing system by suppressing NO production.

Animals↗
PubMed1994

Encapsulation of Cryptococcus neoformans regulates fungicidal activity and the antigen presentation process in human alveolar macrophages.

Our previous studies have shown that unstimulated alveolar macrophages (AM) play a predominant role as antigen-presenting cells in Cryptococcus neoformans infections, while the function as effector cells seems to be of minor relevance. The present study focuses on the role of encapsulation of C. neoformans on fungicidal activity and the antigen presentation process of AM. Fungicidal activity in unstimulated AM occurs to a higher degree when the acapsular strain is employed, but this is impaired compared with other natural effectors, such as peripheral blood monocytes (PBM) and polymorphonuclear (PMN) cells. Cryptococcus-laden AM also induce a higher proliferative response in autologous CD4+ lymphocytes when the acapsular strain is used compared with encapsulated yeast. The enhanced blastogenic response is, in part, ascribed to an augmented IL-2 production by T cells. In addition, higher levels of interferon-gamma (IFN-gamma), but not IL-4, are produced by the responding T cells, when the acapsular strain is used compared with the encapsulated yeast. Moreover, IFN-gamma is able to induce fungicidal activity in AM against the encapsulated yeast and augments killing activity of the acapsular strain. This phenomenon is not mediated by nitric oxide production, but is correlated with an enhancement of fungicidal activity of cytoplasmic cationic proteases. We speculate that encapsulation of C. neoformans could down-regulate the development of the immune response mediated by Cryptococcus-laden AM at lung level.

Adult↗
PubMed2004

Fungicide activity through activation of a fungal signalling pathway.

Fungicides generally inhibit enzymatic reactions involved in fungal cellular biosynthesis. Here we report, for the first time, an example of fungicidal effects through hyperactivation of a fungal signal transduction pathway. The OSC1 gene, encoding a MAP kinase (MAPK) related to yeast Hog1, was isolated from the fungal pathogen Colletotrichum lagenarium that causes cucumber anthracnose. The osc1 knockout mutants were sensitive to high osmotic stress and showed increased resistance to the fungicide fludioxonil, indicating that Osc1 is involved in responses to hyperosmotic stress and sensitivity to fludioxonil. The Osc1 MAPK is phosphorylated under high osmotic conditions, indicating activation of Osc1 by high osmotic stress. Importantly, fludioxonil treatment also activates phosphorylation of Osc1, suggesting that improper activation of Osc1 by fludioxonil has negative effects on fungal growth. In the presence of fludioxonil, the wild-type fungus was not able to infect the host plant because of a failure of appressorium-mediated penetration, whereas osc1 mutants successfully infected plants. Analysis using a OSC1-GFP fusion gene indicated that Osc1 is rapidly translocated to the nucleus in appressorial cells after the addition of fludioxonil, suggesting that fludioxonil impairs the function of infection structures by activation of Osc1. Furthermore, fludioxonil activates Hog1-type MAPKs in the plant pathogenic fungi Cochliobolus heterostrophus and Botrytis cinerea. These results strongly suggest that fludioxonil acts as a fungicide, in part, through activation of the MAPK cascade in fungal pathogens.

Amino Acid Sequence↗
PubMed1993

Fungicidal properties of defensin NP-1 and activity against Cryptococcus neoformans in vitro.

Defensin NP-1, derived from the neutrophils of rabbits, was tested for its fungistatic and fungicidal activity against strains of Cryptococcus neoformans. The MICs for the encapsulated strains tested ranged from 3.75 to 15.0 micrograms of NP-1 per ml. The minimum fungicidal concentrations for these strains were similar to the MICs. An acapsular strain, however, had a lower MIC of 0.93 and minimum fungicidal concentration of 1.88 micrograms/ml. NP-1 demonstrated time-dependent and concentration-dependent killing of C. neoformans. Killing occurred rapidly in the first 20 min of exposure to NP-1 and was maximum at 90 to 120 min. Killing of C. neoformans by NP-1 was concentration dependent with 31% +/- 9% survival at 25 micrograms/ml, 13% +/- 4% survival at 50 micrograms/ml, 9% +/- 5% survival at 75 micrograms/ml, and 5% +/- 3% survival at 100 micrograms/ml. NP-1's fungicidal effect on C. neoformans was also inoculum dependent, with increased activity observed at 10(4) versus 10(5) or 10(6) cells per ml. In addition, stationary-phase C. neoformans was less susceptible to NP-1 killing than yeast cells in the logarithmic phase. Subinhibitory concentrations of both NP-1 (0.25 x MIC) and fluconazole (0.25 x MIC) acted synergistically in inhibiting growth of C. neoformans. Similar combinations of NP-1 and amphotericin B, however, did not yield synergy.

Amphotericin B↗