Minimum Fungicidal Concentration Values Research Articles

Antifungal activity of mango peel and seed extracts against clinically pathogenic and food spoilage yeasts

The antioxidant and antifungal (antiyeast) properties of mango (Mangifera indica) peel and seed by-products were investigated. Nine extracts were obtained using three cultivars and two extraction methods. Significant differences between cultivars and extraction methods were detected in their bioactive compounds and antioxidant activity. The antifungal property was determined using agar diffusion and broth micro-dilution assays against 18 yeast species of the genera Candida, Dekkera, Hanseniaspora, Lodderomyces, Metschnikowia, Pichia, Schizosaccharomyces, Saccharomycodes and Zygosaccharomyces. All mango extracts showed antifungal activity. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) values were lower for seed than for peel extracts. MICs and MFCs ranged from values <0.1 to 5 and 5 to >30 mgGAE/mL, respectively. The multivariate analysis showed a relationship between antifungal activity, the capacity to inhibit lipid peroxidation and total phenol content. These properties were associated with high levels of proanthocyanidins, gallates and gallotannins in the extracts.

Eugenol, an essential oil of clove, causes disruption to the cell wall of Candida albicans (ATCC 14053)

The aim of this study was to determine the effect of eugenol on the integrity of the cell wall of Candida albicans. Minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and percentage inhibition of diameter growth (PIDG) of eugenol on C. albicans (ATCC 14053) were determined. The effect of eugenol on the growth profile was also evaluated. The release of cellular material and changes in cell permeability, including ultrastructural alterations to the morphology, were assessed using scanning electron microscopy, and surface disruption to the cell wall structure of C. albicans by atomic force microscopy. The MIC and MFC values of eugenol were found to be 1.0% v/v, while the PIDG was dose dependent. Eugenol influenced cell growth and was fungicidal towards C. albicans. Eugenol was also found to encourage cell leakage, causing the release of cellular material, and to increase cell permeability. The ultrastructure and cell surface morphology were also altered by the presence of eugenol. Thus, eugenol was found to disrupt the cell wall of C. albicans.

Chemical Characterization and Anti-Oomycete Activity of Laureliopsis philippianna Essential Oils against Saprolegnia parasitica and S. australis.

Laureliopsis philippiana (Looser) R. Schodde (Monimiaceae) is a native tree widespread in the forest areas in the south of Chile and Argentina, known for its medicinal properties and excellent wood. The aim of this study was to evaluate the chemical composition of L. philippiana leaf and bark essential oils (EOs) using gas chromatography-mass spectrometry (GC-MS), and to quantify its anti-oomycete activity, specifically against Saprolegnia parasitica and S. australis. Only six components were identified in leaf EO, 96.92% of which are phenylpropanoids and 3.08% are terpenes. As for bark EO, 29 components were identified, representing 67.61% for phenylpropanoids and 32.39% for terpenes. Leaf EO was characterized mainly by safrole (96.92%) and β-phellandrene (1.80%). Bark EO was characterized mainly by isosafrole (30.07%), safrole (24.41%), eucalyptol (13.89%), methyleugenol (7.12%), and eugenol (6.01%). Bark EO has the most promising anti-Saprolegnia activity, with a minimum inhibition concentration (MIC) value of 30.0 µg/mL against mycelia growth and a minimum fungicidal concentration (MFC) value of 50.0 μg/mL against spores; for leaf EO, the MIC and MFC values are 100 and 125 µg/mL, respectively. These findings demonstrate that bark EO has potential to be developed as a remedy for the control of Saprolegnia spp. in aquaculture.

Synthesis and antimicrobial activities of acrylamide polymers containing quaternary ammonium salts on bacteria and phytopathogenic fungi

Three series of acrylamide monomers/polymers containing quaternary ammonium salts (QASs), i.e., acrylamide QAS monomers (QDs), homopolymers of QDs (PQDs) and copolymers of QDs with acrylate monomer (PQDCs), were synthesized and employed in antimicrobial tests against both bacteria (Escherichia coli (E. coli) and Staphylococcus albus (S. albus)) and phytopathogenic fungi (Rhizoctonia solani (R. solani) and Fusarium oxysporum f. sp. cubense race 4 (Foc4)). The antibacterial activity of the QASs was evaluated by determining the minimum inhibitory concentration (MIC) against E. coli and S. albus by the TTC coloration method, and the antifungal activity was measured by mycelia growth inhibition as well as MIC and the minimum fungicidal concentration (MFC) values. The results indicated that PQD homopolymers and PQDC copolymers showed far better antimicrobial activities than QD monomers. PQDC copolymers by incorporating hydrophobic acrylate units into the main chain of polyacrylamide backbone displayed even better antimicrobial activities, depending on QAS structure and hydrophobic content. Moreover, polymers with benzyl group attached to nitrogen atom showed better inhibitory effect on bacteria and phytopathogenic fungi. The results could assist understanding and development of future design of antimicrobial polymers as potential fungicide agents to control plant disease.

Phytochemical And Antimicrobial Characterization Of Rhododendron Anthopogon From High Nepalese Himalaya

Abstract The biological and chemical properties of the medicinally important high altitudinal plant Rhododendron anthopogon D. Don were assayed. Extracts at a concentration of 100 mg-ml-1 from leaves and flowers were collectively obtained by employing hot extraction method with different solvents. The antibacterial and antifungal properties were assayed against different clinical bacteria (two Gram+ and six Gram-) and six phytopathogenic fungi. Klebsiella pneumoniae and Salmonella typhimurium were the most inhibited bacteria, while Fusarium eridiforme, a fungus, was highly inhibited. However, all the tested bacteria were resistant to n-hexane and chloroform extracts. Of all the extracts obtained, the ethyl acetate fraction, followed by the hot methanolic extract, was effective against all the pathogenic strains tested. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values of ethyl acetate and aqueous extracts on bacteria ranged from 1.562 mg-ml” 1 to 25.0 mg-ml” 1, whereas MIC and MFC (minimum fungicidal concentration) values of n-hexane and ethyl acetate fractions on fungi varied from 1.562 mg-ml-1 to 12.50 mg-ml-1, which are slightly higher than expected. The extracts showed no activity against Exserohilum turticum and Stenophylum sp. There was a highly significant difference in the zone of inhibition between different extract fractions and bacterial or fungal strains. A preliminary qualitative phyto-chemical assay revealed the presence of polyphenols, reducing compounds, quinones, sterol, triterpenes and fatty acids in leaves and flowers of the test plant. The observed antimicrobial effects are believed to be due to the presence of these compounds. The broad spectrum of activity of the extracts would apparently explain the widespread use of this plant for controlling human pathogenic bacteria and phytopathogenic fungi that widely destroy crops in Nepal. This research reveals R. anthopogon to be a highly promising source of potent antimicrobial drugs that could be used to design therapeutic drugs in the pharmaceutical industry.

Evaluation of antifungal activity of hydroalcoholic extracts of Citrullus colocynthis fruit

Due to the development of resistance to antimicrobial drugs of several multi-drug resistance pathogens, the discovery of new active agents has become a major public health concern. The purpose of this study was to evaluate the antifungal activity of hydroalcoholic extract of Citrullus colocynthis fruits against different Candida and Aspergillus strains. Anti-Candida and anti-Aspergillus effects of the extract were determined by disk diffusion and broth macrodilution methods. The study revealed that all tested fungal strains were sensitive to the extract. The growth inhibition value of the extract showed high antifungal activity against Aspergillus fumigatus and Aspergillus niger and a lesser effect against Candida guilliermondii and Candida kreusei. The minimal inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values ranged from 1.56 to 12.5mg/ml and 3.125 to 25mg/ml, respectively. The results obtained in the present study suggest that C. colocynthis may be a valuable plant source of medicinally useful active compounds that can be used for the treatment of some fungal infections.

Antidermatophytic Activities of Musa sapientum Methanol Leaf Extract in-vitro

ABSTRACT Aim: The in vitro antidermatophytic activity of methanol leaf extract of Musa sapientum (MSL) against Microsporum canis, Trichophyton tonsurans and Trichophyton rubrum was investigated. Methodology: The methanol leaf extract M. sapientum was obtained by cold extraction. The antifungal activity of the extract was assayed using agar well diffusion techniques. The time-kill antibacterial kinetics of the extract was assessed against one strain of M. canis and two strains of T. tonsurans by plate count technique. Results: The extract had minimum fungicidal concentration (MFC) and minimum inhibitory concentration (MIC) values ranging from 0.0625 mg/ml to 0.5 mg/ml. The least MIC and MFC value was 0.0625 mg/ml against M. canis while T. tonsurans showed the highest MIC and MFC value of 0.5 mg/ml. The extract had no inhibitory or fungicidal effect against T. rubrum . Time-kill kinetic study indicated that the extract exhibited bacteriostatic and bacteriocidal effects against Microsporum canis and Trichophyton tonsurans. Conclusion: The results obtained suggest that the methanol leaf extract of Musa sapientum possesses antidermatophytic properties. Original Research Article

Pharmacological synergism of bee venom and melittin with antibiotics and plant secondary metabolites against multi-drug resistant microbial pathogens

The goal of this study was to investigate the antimicrobial activity of bee venom and its main component, melittin, alone or in two-drug and three-drug combinations with antibiotics (vancomycin, oxacillin, and amikacin) or antimicrobial plant secondary metabolites (carvacrol, benzyl isothiocyanate, the alkaloids sanguinarine and berberine) against drug-sensitive and antibiotic-resistant microbial pathogens. The secondary metabolites were selected corresponding to the molecular targets to which they are directed, being different from those of melittin and the antibiotics.The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were evaluated by the standard broth microdilution method, while synergistic or additive interactions were assessed by checkerboard dilution and time-kill curve assays. Bee venom and melittin exhibited a broad spectrum of antibacterial activity against 51 strains of both Gram-positive and Gram-negative bacteria with strong anti-MRSA and anti-VRE activity (MIC values between 6 and 800 µg/ml). Moreover, bee venom and melittin showed significant antifungal activity (MIC values between 30 and 100 µg/ml). Carvacrol displayed bactericidal activity, while BITC exhibited bacteriostatic activity against all MRSA and VRE strains tested (reference strains and clinical isolates), both compounds showed a remarkable fungicidal activity with minimum fungicidal concentration (MFC) values between 30 and 200 µg/ml. The DNA intercalating alkaloid sanguinarine showed bactericidal activity against MRSA NCTC 10442 (MBC 20 µg/ml), while berberine exhibited bacteriostatic activity against MRSA NCTC 10442 (MIC 40 µg/ml).Checkerboard dilution tests mostly revealed synergism of two-drug combinations against all the tested microorganisms with FIC indexes between 0.24 and 0.50, except for rapidly growing mycobacteria in which combinations exerted an additive effect (FICI = 0.75–1). In time-kill assays all three-drug combinations exhibited a powerful bactericidal synergistic effect against MRSA NCTC 10442, VRE ATCC 51299, and E. coli ATCC 25922 with a reduction of more than 3log10 in the colony count after 24 h. Our findings suggest that bee venom and melittin synergistically enhanced the bactericidal effect of several antimicrobial agents when applied in combination especially when the drugs affect several and differing molecular targets. These results could lead to the development of novel or complementary antibacterial drugs against MDR pathogens.

Susceptibility of Microsporum canis arthrospores to a mixture of chemically defined essential oils: a perspective for environmental decontamination.

The zoophilic dermatophyte Microsporum canis has cats as natural reservoir, but it is able to infect a wide range of hosts, including humans, where different clinical features of the so-called ringworm dermatophytosis have been described. Human infections are increasingly been reported in Mediterranean countries. A reliable control program against M. canis infection in cats should include an antifungal treatment of both the infected animals and their living environment. In this article, a herbal mixture composed of chemically defined essential oils (EOs) of Litsea cubeba (1%), Illicium verum, Foeniculum vulgare, and Pelargonium graveolens (0.5% each) was formulated and its antifungal activity assessed against M. canis arthrospores which represent the infective environmental stage of M. canis. Single compounds present in higher amounts in the mixture were also separately tested in vitro. Litsea cubeba and P. graveolens EOs were most effective (minimum inhibitory concentration (MIC) 0.5%), followed by EOs of I. verum (MIC 2%) and F. vulgare (MIC 2.5%). Minimum fungicidal concentrations (MFC) values were 0.75% (L. cubeba), 1.5% (P. graveolens), 2.5% (I. verum) and 3% (F. vulgare). MIC and MFC values of the mixture were 0.25% and 0.5%, respectively. The daily spray of the mixture (200 μL) directly onto infected hairs inhibited fungal growth from the fourth day onwards. The compounds present in higher amounts exhibited variable antimycotic activity, with MIC values ranging from >10% (limonene) to 0.1% (geranial and neral). Thus, the mixture showed a good antifungal activity against arthrospores present in infected hairs. These results are promising for a further application of the mixture as an alternative tool or as an adjuvant in the environmental control of feline microsporosis.

Evaluation of Antibacterial and Antifungal Properties of Alchornea laxiflora (Benth.) Pax. & Hoffman.

Alchornea laxiflora leaf extract was tested against a range of microorganisms using standard microbiological methods for antimicrobial activities. The extract inhibited the growth of all the bacterial and 15 fungal isolates tested. The zones of inhibition exhibited against the test bacteria ranged between 12 mm and 24 mm and between 11 mm and 24 mm for the extract and the antibiotic streptomycin, respectively. The zones of inhibition observed against the fungal isolates by the extract ranged between 12 mm and 23 mm. The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) exhibited by the extract against test bacteria ranged between 0.78 mg/mL–25 mg/mL and 1.56 mg/mL–25 mg/mL, respectively, while the MICs and minimum fungicidal concentrations (MFCs) values for the test fungi ranged between 8.75 mg/mL–35.00 mg/mL and 8.75 mg/mL–35.00 mg/L, respectively. The preliminary phytochemical screening of the extract revealed the presence of alkaloids, tannins, flavonoids, saponins, and reducing sugars as major phytoconstituents in the extract. A. laxiflora leaf extract is a potent source of antibacterial and antifungal compounds; further studies on the extract are ongoing in our laboratories to elucidate the probable mechanism(s) of action on bacteria and fungi found to be susceptible to the extract.

IN VITRO AND IN VIVO ANTIFUNGAL ACTIVITY OF EIGHT MEDICINAL PLANTS AGAINST CITRUS SOUR ROT AGENT GEOTRICHUM CANDIDUM

The aim of this work was finding an alternative to the chemical fungicides currently used in the control of Geotrichum candidum, the cause of citrus sour rot. Hexane, chloroform, ethyl acetate and methanol extracts of eight medicinal plants were evaluated for their in vitro and in vivo antifungal activity against G. candidum. Cistus villosus, Ceratonia siliqua and Halimium umbellatum methanol extracts proved to be the most effective, totally inhibiting arthrospore germination of G. candidum at concentrations below 2.5 mg/ml. The methanol extracts of H. umbellatum, C. villosus and C. siliqua exhibited strong antifungal activity with minimum inhibitory concentration values ranging between 0.156 and 1.25 mg/ml, and minimum fungicidal concentration values ranging from 2.5 to 5 mg/ml. Incidence of sour rot was reduced to 0.00, 3.33 and 11.66% when mandarin fruits were treated with 50 mg/ml of C. villosus, C. siliqua and H. umbellatum methanol extracts, respectively, compared with 95% incidence in the untreated control. These findings suggest that C. villosus, H. umbellatum and C. siliqua plant extracts may be effective agents for the control of citrus sour rot. Such natural products therefore represent a sustainable alternative to the use of synthetic fungicides.

Antifumonisin Efficacy of 2-Hydroxy-4-Methoxybenzaldehyde Isolated from Decalepis hamiltonii

Fumonisins are mycotoxins primarily produced by Fusarium verticillioides that grow on food and feedstuffs. In the present investigation, the antifumonisin activity of 2-hydroxy-4-methoxybenzaldehyde isolated from Decalepis hamiltonii was evaluated. The results demonstrated that the compound 2-hydroxy-4-methoxybenzaldehyde exhibited dose-dependent antifungal activity with the zone of inhibition, minimum inhibitory concentration and minimum fungicidal concentration values 14.8 mm (at 500 μg/disc), 100 and 500 μg/mL, respectively. The fumonisin B1 production was completely inhibited at 400 mg/L under in vitro and 750 mg/kg under in vivo. There were no adverse effects observed in treated seed samples. The present findings indicate the possible use of 2-hydroxy-4-methoxybenzaldehyde as an alternative agent for management of fusarial growth and mycotoxins contamination.

Evaluation of Inhibitory Effect of Organic and Inorganic Salts Against Ilyonectria liriodendri, The Causal Agent of Root Rot Disease of Kiwifruit

AbstractThis study evaluated efficacy of 42 organic and inorganic salts as possible alternatives to synthetic fungicides for the control of Ilyonectria root rot of kiwifruit. Preliminary in vitro tests showed that ammonium bicarbonate, ammonium carbonate, potassium benzoate, potassium sorbate, sodium benzoate and sodium metabisulphite at 2% completely inhibited mycelial growth of the fungus. No significant differences were observed among these salts and disodium EDTA (P ≤ 0.05). However, the ED50, minimum inhibition concentration (MIC), and minimum fungicidal concentration (MFC) values indicated that sodium metabisulphite was more toxic to Ilyonectria liriodendri than these other six salts. Soil bioassays showed that sodium metabisulphite, sodium benzoate and potassium sorbate at 0.25% completely inhibited mycelial growth of the fungus, whereas potassium benzoate reduced the mycelial growth of fungus by 90.30%; however, the differences in inhibitory effects were statistically insignificant (P ≤ 0.05). Moreover, there was no significant difference between 0.1% sodium metabisulphite and 0.5% ammonium carbonate, 0.75% ammonium bicarbonate and 1.5–2.0% disodium EDTA (P ≤ 0.05). Unlike disodium EDTA, complete inhibitory was observed with ammonium carbonate and ammonium bicarbonate at higher concentrations. However, in root bioassays, applications of 2% ammonium bicarbonate, 1.5% ammonium carbonate and 2% disodium EDTA were phytotoxic to kiwifruit seedlings, but 0.25% four other salts were neither phytotoxic to kiwifruit seedlings nor did it adversely affect root length, root fresh weight and root dry weight of seedling. This study also showed I. liriodendri to be capable of growth in both acidic and basic environments. However, while the fungus showed uninhibited growth at pH values of 5–11, growth decreased significantly at both higher and lower pH values (P ≤ 0.05) and was completely inhibited at pH 12.

Synthesis and antimicrobial activities of polysiloxane-containing quaternary ammonium salts on bacteria and phytopathogenic fungi

A series of dimethylaminopropyl benzyl chloride grafted polysiloxanes (PDMS-g-BCs) with tunable molecular weights and cationic content were synthesized, and the effect of polymer structure on the antimicrobial activities against bacteria (Escherichia coli (E. coli) and Staphylococcus albus (S. albus)) and phytopathogenic fungi (Rhizoctonia solani (R. solani) and Fusarium oxysporum f. sp. cubense race 4 (Foc4)) were systematically assessed. The antibacterial activity was evaluated by determining the minimum inhibitory concentration (MIC) against E. coli and S. albus by the broth dilution method, and the antifungal activity was measured by mycelia growth inhibition as well as by the MIC and minimum fungicidal concentration (MFC) values. The molecular weight and cationic content were major determinants of the activities of PDMS-g-BCs; when the molecular weight was approximately 2500g/mol and the cationic content was approximately 20mol% of the total siloxane units, PDMS-g-BCs gained strong antimicrobial activities toward both E. coli and Foc4, comparable to those of a commonly used broad-spectrum microbicide benzalkonium chloride, making PDMS-g-BCs promising fungicidal agents for plant disease control.

Antifungal Activity of Apple Cider Vinegar on Candida Species Involved in Denture Stomatitis.

To evaluate the in vitro antifungal activity of apple cider vinegar on Candida spp. involved in denture stomatitis. The microdilution technique was used to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of apple cider vinegar containing 4% maleic acid, and nystatin (control). Further tests of microbial kinetics and inhibition of adherence to acrylic resin were performed testing different concentrations (MIC, MICx2, MICx4) of the products at time intervals of 0, 30, 60, 120 and 180 minutes. A roughness meter was used to measure the changes in surface roughness; color change of the acrylic resin specimens exposed to the test products in different concentrations and time intervals were also evaluated. Apple cider vinegar (4%) showed MIC of 2500 μg/ml and MFC of 2500, 5000, and 10,000 μg/ml depending on the strain tested. Nystatin showed MIC of 3.125 μg/ml and strain-dependent MFC values ranging from 3.125 to 12.5 μg/ml. The microbial kinetic assay showed a statistical difference between apple cider vinegar and nystatin (p < 0.0001). After 30 minutes of exposure, apple cider vinegar showed fungicidal effect at MICx4, whereas nystatin maintained its fungistatic effect. Apple cider vinegar showed greater inhibition of adherence (p < 0.001) compared to control. Apple cider vinegar did not significantly alter the surface roughness of the acrylic resin specimens compared to nystatin (p > 0.05), and both had no influence on their color. Apple cider vinegar showed antifungal properties against Candida spp., thus representing a possible therapeutic alternative for patients with denture stomatitis.

Influence of pH and temperature variations on vapor phase action of an antifungal food packaging against five mold strains

Abstract An antifungal active food packaging containing cinnamon essential oil has been evaluated under different pH and temperature. Cinnamon essential oil was previously chosen among oregano, clove and their major components cinnamaldehyde, carvacrol and eugenol respectively. Minimal Inhibitory Concentration (MIC) and Minimal Fungicidal Concentration (MFC) were determined by macrodilution method against two strains of Aspergillus flavus as well as Aspergillus niger , Penicillium roqueforti and Penicillium expansum . Despite pH and temperature modified the growth rate of the molds, these variables did not affect the MIC and MFC values. The active food packaging, consisting of Polypropylene films coated with a formula containing 2%–6% cinnamon were produced and evaluated. The antifungal activity was studied against two A flavus , P roqueforti and P. expansum at different pH and temperature. The results highlighted the growth delay caused by the PP 2% in all cases. Total inhibition was obtained with higher amount of cinnamon. This fungicidal action was maintained beyond the 30 days of the experiments. Long-term properties were confirmed after 3 months. The fridge temperature did not hamper the antifungal action of the cinnamon volatile compounds. Finally, all these results demonstrated the high-performance of the antifungal packaging, what guarantee an efficient and durable antifungal protection.

Preliminary studies on the antifungal activities of the successive extracts of Mitracarpus villosus (Sw.) Dc aerial parts obtained in Abuja, Nigeria

Aim: A worldwide increase in the incidence of fungal infections has been observed in the past few decades, with a rise in the resistance of some fungal species to different fungicidal agents used in medicinal practice. This study aims at evaluating the antifungal properties of Mitracarpus villosus. Methodology and results: The aerial parts of M. villosus was subjected to successive extraction with hexane, ethyl acetate and ethanol. The powdered plant was screened for phyto-compounds. Antifungal activities of the ethyl acetate extracts against clinical isolates of Candida albicans, C. krusei, Trichophyton verrucosum, T. mentagrophytes, Aspergillus fumigatus and A. niger were investigated using agar diffusion, broth dilution and micro broth dilution methods. The antibiotic susceptibility profiles of the fungal isolates to fluconazole and ketoconazole were also determined. Phytochemical screening of Mitracarpus villosus revealed the presence of tannins, saponins, flavonoids, terpenes, phenols and resins. The results of the zones of inhibition showed that the ethyl acetate extract of Mitracarpus villosus produced the strongest antifungal activity with diameter zones of inhibition ranging from 18.67-21.67 mm at an exposure concentration of 12.5 mg/mL. The minimum inhibitory concentration and minimum fungicidal concentration values of the ethyl acetate extract against all the fungal isolates tested were 0.5-2.0 mg/mL and 2.0-8.0 mg/mL respectively. Conclusion, significance and impact study: The results confirm the claims of traditional healers in the use of the plant. This plant holds great promise for development into phytomedicine for the treatment of fungal infections in the near future.

English

Results from the in vitro evaluation of the antibacterial and antifungal activities of six plant extracts indicated that the aqueous and the methanol extracts of Acalypha wilkesiana leaves and Ageratum conyzoides leaves exhibited good and efficient antifungal activity against Candida albicans with minimum inhibitory concentration (MIC) of 31.25 &micro;g/ml and minimum fungicidal concentration (MFC) of 62.5 &micro;g/ml) while the methanol extract from Pentaclethra macrophylla inhibited the yeast growth with minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of 62.5 and 125 &micro;g/ml respectively. The aqueous extracts from Acalypha wilkesiana, Ageratum conyzoides, Buccholzia tholoniana seeds, Gulboutia demeusei root and the aqueous and methanol extracts from Pentaclecthra macrophylla stem bark showed good antibacterial activity against Escherichia coli, Klebsiella oxytoca, Proteus mirabilis, Salmonella thyphimurium, Stahylococcus aureus and Shigella flexneri with minimum inhibitory concentration (MIC) of 62.5 &micro;g/ml and minimum bactericidal concentration (MBC) of 125 &micro;g/ml according to the case. These results partly support and justify the traditional use of these plant extracts for treating infections in traditional medicine. &nbsp; Key words: Plant extracts, antibacterial, antifungal, infections.

Evaluation of antifungal activity of sodium salts against onion basal rot caused by Fusarium oxysporum f.sp. cepae

The efficacy of twelve sodium salts as possible alternatives to synthetic fungicides for the control of onion basal rot caused by&amp;nbsp;Fusarium oxysporum&amp;nbsp;f.sp.&amp;nbsp;cepae&amp;nbsp;was evaluated.&amp;nbsp;In vitro&amp;nbsp;tests showed that there were significant differences between the inhibitory effects of sodium salts on the mycelial growth (P&amp;nbsp;&amp;le; 0.05) and 2% (w/v) concentrations of sodium metabisulfite and sodium fluoride completely inhibited mycelial growth of the fungus, while other salts did not. Sodium metabisulfite and sodium phosphate monobasic had lower pH values than the other salts. Unlike sodium metabisulfite, sodium phosphate monobasic could not decrease the mycelial growth. The ED&lt;sub&gt;50&lt;/sub&gt;, minimum inhibition concentration (MIC), and minimum fungicidal concentration (MFC) values indicated that sodium metabisulfite was more inhibitory to the fungus compared to sodium fluoride. In soil tests, inhibitory effect of sodium metabisulfite on the fungus was higher than that of sodium fluoride, where sodium metabisulfite completely inhibited mycelial growth at even 0.4% concentration.

Antifungal activity of essential oil of Ziziphora clinopodioides and the inhibition of aflatoxin B1 production in maize grain

The aim of this study was to determine the antifungal effect of the essential oil obtained from Ziziphora clinopodioides L on two fungi species including Aspergillus flavus and Aspergillus parasiticus using microdilution method. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were determined for the essential oil at 10 different concentrations (i.e. 25,000, 12,500, 6250, 3125, 1562.5, 781.25, 390.625, 195.31, 97.65, and 48.82 µg/ml). Finally, the effect of the essential oil at six levels (6250, 3125, 1600, 800, 400, and 196 µg/ml) was investigated on the growth and activity of A. flavus and A. parasiticus, and also toxin production of these species in maize at 0.97 aw and 25°C after 29 days. Aflatoxin B1 (AFB1) content was assayed by enzyme linked immuno-sorbent assay technique. Results showed that essential oil of Z. clinopodioides was found more effective on A. parasiticus than A. flavus in both in vitro and in vivo conditions. Z. clinopodioides oil exhibited the same MIC value in the liquid medium against all fungal strains (48.82 µg/ml), while it showed different activity against A. flavus and A. parasiticus with MFC values of 781.25 and 390.625 µg/ml respectively. Under storage condition in maize, AFB1 production was significantly (p < 0.05) repressed at the concentration of 6250 µg/ml for A. flavus and 6250 and 3125 µg/ml for A. parasiticus. At the lower concentrations, the AFB1 production increased gradually. The results of the present study indicated that the essential oil of Z. clinopodioides had significant antifungal activity (p < 0.05); therefore, it can be used as an antifungal agent in the food and medicinal industries.