Fungus Trichophyton Research Articles

Joule heating influence on the vitality of fungi in pulsed magnetic fields during magnetic permeabilization

Generation of the pulsed magnetic fields that are 5–6 orders of magnitude higher than the geomagnetic field requires switching of high pulsed currents. As a result, the occurrence of the Joule heating in the inductors limits the possible biological applications of the pulsed magnetic fields. This work is focused on the investigation of the generated Joule heating inside the inductors of different shapes. The analysis of the Joule heating influence on the vitality of biological objects during magnetic permeabilization is presented. The biological objects that are used in the study are the pathogenic fungi Candida albicans and Trichophyton rubrum, which are the common cases for human infections. The finite element method analysis of the pulsed inductors and the experimental results with the selected pathogenic fungi are overviewed. The limitations of the magnetic permeabilization technique due to the generated Joule heating are identified.

English

Antimicrobial activities of Cirsium species (Cirsium arvense and cirsium japonicum) was evaluated against six bacterial species, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa (clinical strain/PIMS), Enterobacter (clinical strain/PIMS), Staphylococcus aureus (MRSA, clinical strain/PIMS) and six fungus Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Candida glaberata and Fusarium solani. The methanolic extracts of these plants were fractionated with n-hexane to get (F1), chloroform (F2), ethyl acetate(F3), n-butanol(F4) and methanolic fraction (F5). The agar well diffusion assay and agar dilution susceptibility testing were carried out to determine the zone of inhibitions and the minimum inhibitory concentration, respectively. Ager well diffusion methods was used for antifungal activity. The zones of inhibition were determined using standard agent. The entire fraction showed some activity against these pathogens, but F2 of both plants shows very good activity. The present study explains the potential antimicrobial properties of C. arvense and C. japonicum. From these observations, it is clear that Cirsium species contain antimicrobial constituents. Key words: Traditional medicine, crude extract, antimicrobial activities, Cirsium arvense, cirsium japonicum.

Chlorinated Imidazole Complexes as Potent Antifungal Agents

dichloroimidazole (DCI) was synthesized and characterized using spectroscopic methods. The compound and its complexes did not show any significant antibacterial activity against Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa and Proteus spp, when compared with the good activity shown by imidazole which is its precursor compound. Imidazole however showed complete inactivity against the fungi strains Aspergillus spp, Candida spp and Trichophyton spp. These fungi were very sensitive to DCI with further sensitivity shown to the Cr 3+ and Co 2+ complexes of the compound. These two complexes of DCI were also more active than the standard antifungal drug ketoconazole in inhibiting the growth of these fungi making them very potent compounds in the search for antifungal agents.

Identification and characterisation of non-coding small RNAs in the pathogenic filamentous fungus Trichophyton rubrum

BackgroundAccumulating evidence demonstrates that non-coding RNAs (ncRNAs) are indispensable components of many organisms and play important roles in cellular events, regulation, and development.ResultsHere, we analysed the small non-coding RNA (ncRNA) transcriptome of Trichophyton rubrum by constructing and sequencing a cDNA library from conidia and mycelia. We identified 352 ncRNAs and their corresponding genomic loci. These ncRNA candidates included 198 entirely novel ncRNAs and 154 known ncRNAs classified as snRNAs, snoRNAs and other known ncRNAs. Further bioinformatic analysis detected 96 snoRNAs, including 56 snoRNAs that had been annotated in other organisms and 40 novel snoRNAs. All snoRNAs belonged to two major classes—C/D box snoRNAs and H/ACA snoRNAs—and their potential target sites in rRNAs and snRNAs were predicted. To analyse the evolutionary conservation of the ncRNAs in T. rubrum, we aligned all 352 ncRNAs to the genomes of six dermatophytes and to the NCBI non-redundant nucleotide database (NT). The results showed that most of the identified snRNAs were conserved in dermatophytes. Of the 352 ncRNAs, 102 also had genomic loci in other dermatophytes, and 27 were dermatophyte-specific.ConclusionsOur systematic analysis may provide important clues to the function and evolution of ncRNAs in T. rubrum. These results also provide important information to complement the current annotation of the T. rubrum genome, which primarily comprises protein-coding genes.

Role of Shodhana on Antimicrobial Activity of Tuttha

Normal 0 false false false EN-MY JA X-NONE Tuttha is one among the Maharasas , well known and frequently used mineral in Rasaaushadis . Ayurveda classical texts indicate to use in skin diseases, ulcer, sinus, worm infection, vitiligo, obesity, pain, asthma, hyper acidity, hemorrhoids, diseases of eyes and as Krimighna etc. But advocates only after specific procedures called Shodhana (purification procedures) before making any pharmaceutical form since crude Tuttha causes vomiting and giddiness etc. The present antimicrobial study was carried out on two Tuttha named crude Tuttha and Shodhita Tuttha before and after Shodhana. Antibacterial activity on Escherichia coli, Bacillus subtilis, Salmonella typhi, Staphylococcus aureus bacterias and antifungal activity on fungi Candida albicans and Trichophyton rubrum were carried out by agar disk diffusion method. The shodhana process results that Shodhita Tuttha was found to be more effective compared to crude, as the diameter of the zone of inhibition was higher, even at low concentration of 1mg. The present study shows the importance of Shodhana process by enhancing the antimicroabial activity.

Antidermatophytic activity of volatile oil and nanoemulsion of Stenachaenium megapotamicum (Spreng.) Baker

Volatile oils have important biological properties, like antifungal activity. Several studies have investigated the ability of nanoparticulate systems as carriers of these substances in order to stabilize and reduce their volatility and improve their effects. The aims of this study were to analyze the chemical composition of volatile oil of Stenachaenium megapotamicum and to evaluate the antifungal activity of the pure oil and its nanoemulsion. The volatile oil obtained by hydrodistillation was analyzed by gas chromatography coupled to mass spectrometry and presented 52.6% of sesquiterpenes. Fokienol was the most abundant compound (24.4%), followed by 7-(isopentyloxy)-2H-chromen-2-one (17.9%), thymol (10.8%) and β-bisabolene (9%). The nanoemulsion was obtained by spontaneous emulsification and exhibited translucent appearance, pH 5.14, particle diameter of 210nm and polydispersity of 0.369. Apart from volatile oil and nanoemulsion, thymol also was tested for antifungal activity. The volatile oil and thymol exhibited antidermatophytic activity, presenting selectivity against the filamentous fungi Epidermophyton floccosum, Scytalidium dimidiatum and Trichophyton rubrum. Significantly reduced minimal inhibitory concentration and minimal fungicidal concentration were observed for the nanoemulsion containing volatile oil of S. megapotamicum, when compared with the activity of pure oil and of thymol, demonstrating the ability of the nanoparticulate system to improve oil activity.

Antioxidant and anti-dermatophytic properties leaf and stem bark of Xylosma longifolium clos.

BackgroundThe present study was carried out to assess the phytochemical and anti-dermatophytic effect of the leaf and bark extracts of Xylosma longifolium Clos. The leaf and stem bark are used by the indigenous people of Manipur, India for treatment of skin diseases.MethodsThe leaves and stem barks of Xylosma longifolium were extracted using petroleum ether, chloroform and methanol respectively. The different extracts of each plant parts were tested for antioxidant activity using DPPH assay. The phenolic content was assayed using Folin-Ciocalteu colorimetric method. Each extracts was further analysed by RP-HPLC to quantify some individual flavonoid components. The anti-dermatophytic activity was evaluated both by agar diffusion method and micro wells dilution method against the Microsporum boullardii MTCC 6059, M. canis (MTCC 2820 and MTCC 32700), M. gypseum MTCC 2819, Trichophyton ajelloi MTCC 4878, T. rubrum (MTCC 296 and MTCC 3272).ResultsThe free radical scavenging activity values were ranged from 0.7 to 1.41 mg/ml and 0.6 to 1.23 mg/ml, respectively for leaf and stem bark extracts. The amount of total phenolic contents of the extracts occurred in both leaf and bark in the range of 12 to 56.6 mg GAE/100 g and 16 to 58 mg GAE/100 g respectively. RP-HPLC analysis for flavonoids revealed the presence of two major flavonoid compounds, rutin and catechin. Kaempferol was in trace or absent. Methanol leaf extract showed significant low inhibitory effect against tested fungus Trichophyton ajelloi MTCC 4878 (0.140625 mg/ml) as the most sensitive. These finding suggest that the methanol leaf extract tested contain compounds with antimicrobial properties.ConclusionThe results of our study may partially justify the folkloric uses on the plant studied and further provide an evidence that the leaf extract of Xylosma longifolium might be indeed a potential sources of antimicrobial agents.

Human pathogenic fungus Trichophyton schoenleinii activates the NLRP3 inflammasome

The fungus Trichophyton schoenleinii (T. schoenleinii) is the causative agent of Trichophytosis and Tinea favosa of the scalp in certain regions of Eurasia and Africa. Human innate immune system plays an important role in combating with various pathogens including fungi. The inflammasome is one of the most critical arms of host innate immunity, which is a protein complex controlling maturation of IL-1β. To clarify whether T. schoenleinii is able to activate the inflammasome, we analyzed human monocytic cell line THP-1 for IL-1β production upon infection with T. schoenleinii strain isolated from Tinea favosa patients, and rapid IL-1β secretion from THP-1 cells was observed. Moreover, applying competitive inhibitors and gene specific silencing with shRNA, we found that T. schoenleinii induced IL-1β secretion, ASC pyroptosome formation as well as caspase-1 activation were all dependent on NLRP3. Cathepsin B activity, ROS production and K⁺ efflux were required for the inflammasome activation by T. schoenleinii. Our data thus reveal that the NLRP3 inflammasome plays an important role in host defense against T. schoenleinii, and suggest that manipulating NLRP3 signaling can be a novel approach for control of diseases caused by T. schoenleinii infection.

Transgenic expression of an insect diapause-specific peptide (DSP) in Arabidopsis resists phytopathogenic fungal attacks

Diapause-specific peptide (DSP) is an insect antimicrobial peptide, composed of 41 amino acid residues including six cysteines and isolated from diapausing adults of the leaf beetle Gastrophysa atrocyaneais. Recent research results have been demonstrated that in vitro, DSP has selective antifungal activity against the higher animal pathogenic fungus Trichophyton rubrum and the plant phytopathogenic fungus Fusarium solani. To elucidate the effect of DSP on other phytopathogenic fungi, we respectively introduced a Cht1SP-DSP-FLAG fusion gene and Cht1SP-FLAG fusion gene into Arabidopsis ecotype col-0. Transgenic plants expressing Cht1SP-DSP-FLAG fusion gene showed significant resistance to Golovinomyces cichoracearum (biotrophic fungus), Botrytis cinerea (necrotrophic fungus) and Hyaloperonospora arabidopsidis (H. a.) Noco2 (oomycete), whilst transgenic plants expressing Cht1SP-FLAG fusion gene showed no resistance to these pathogens. These results indicated that for many plant pathogenic fungi, DSP has high antimicrobial activity, which suggests that DSP has a huge potential in protecting crops from damage from phytopathogenic fungi.

Synthesis and biocidal activity of modified poly(vinyl alcohol)

Functionalized polymers and their polymer nature give them more advantages than the corresponding small molecules. In this respect, polymeric ammonium and phosphonium salts were prepared by chemical modifications of poly(vinyl alcohol) (PVA) aiming to explore their antimicrobial activities against pathogenic bacteria and fungi. The modifications were performed by chloroacetylation with chloroacetyl chloride. Incorporation of the ammonium and phosphonium salts was conducted by the reaction of chloroacetylated poly(vinyl alcohol) (CPVA) with triethylamine (TEA), triphenylphosphine (TPP), and tributylphosphine (TBP). The antimicrobial activity of the polymers against variety of test microorganisms was examined by the cut plug and viable cell counting methods of shake cultures of 10 times dilute nutrient broth and Sabouraud’s media, seeded with the test microorganisms. It was found that the immobilized polymers exhibited antimicrobial activity against the Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Shigella sp. and Salmonella typhi) and Gram positive bacteria (Bacillus subtilis and B. cereus) and the dermatophyte fungus (Trichophyton rubrum). The growth inhibition of the test microorganisms (ratio of surviving cell number, M/C) varied according to the composition of the active group in the polymer and the test organism. It increased by increasing the concentration of the polymer. Triphenyl phosphonium salt of the modified poly(vinyl alcohol) exhibited the most biocidal activity against both Gram-negative and Gram-positive bacteria after 24h.

Phytochemical study and screening for antimicrobial activity of flavonoids of Euphorbia hirta

Objective:This study aims to phytochemical and antimicrobial study of Euphorbia hirta Euphorbiaceae).Materials and Methods:Antimicrobial activity of flavonoids (free and bound) of Euphorbia hirta L. was determined by disc diffusion assay against four bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, and Staphylococcus aureus) and four fungi (Aspergillus flavus, Aspergillus niger, Trichophyton mentagrophytes, and Candida albicans). Minimum inhibitory concentration (MIC) of the extract was evaluated through micro broth dilution method, while minimum bactericidal/fungicidal concentration was determined by subculturing the relevant samples. Total activity (TA) of extracts against each sensitive pathogen was also evaluated.Results:Out of fungi; A. flavus, A. niger, and T. mentagrophytes were found to be resistant, against which none of the tested extracts showed activity. Bound flavonoids extract of root showed best activity against C. albicans (inhibition zone (IZ) 27.66, MIC 0.039, minimum fungicidal concentration (MFC) 0.039). TA of free flavonoid extract of root was found to be the same for P. mirabilis and S. aureus (192.30 ml/g). Two flavonoids quercetin and kaempferol were identified in the bound flavonoids of stem extract which showed activity against all the microorganisms.Conclusion:Results of the present investigation indicate that E. hirta has good antimicrobial activity with low range of MIC, hence can be exploited for future plant-based antimicrobial drugs.

In vitro antimicrobial and cytotoxic activity of Tamarix dioica Roxb. leaves

Medicinal plants have been in use for thousands of years for treatment of different types of diseases and a large inventory of useful drugs has been isolated from them. The aim of our study is to investigate a new and effective plant possessing antimicrobial activity. The crude extracts of Tamarix dioica Roxb. leaves, as well as fractions of the extract in various solvents, were investigated against standard strains of bacteria Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Shigella flexneri, Bacillus subtilis, Salmonella typhi, and Staphylococcus aureus and fungi Candida glabrata, Aspergillus niger, Trichophyton rubrum, Candida tropicalis, and Aspergillus fumigatus. For in vitro antibacterial and antifungal studies of T. dioica extracts, the agar well diffusion technique was used. For cytotoxic study, brine shrimp (Artemia salina) larvae were used. Results of the crude extract and some fractionated samples showed significant antifungal properties, but low antibacterial response and negligible cytotoxic activity. It was recognized that Tamarix dioica has the potential for future development of new antifungal drugs/medicine.

Endophytic fungi occurring in Ipomoea carnea tissues and their antimicrobial potentials

The aim of this work was to study the endophytic fungi associated with the tissues of Ipomoea carnea, a common invasive plant of India. A total of 69 isolates belonging to ten taxa comprising 1.45% Zygomycetes, 10.14% Coelomycetes, 62.32% Hypomycetes, 18.84% sterile mycelia and 7.25% unidentified species were obtained. Species of Curvularia, Aspergillus, Fusarium, Colletotrichum and sterile fungus were isolated as dominant endophytes. Colonization frequency of Curvularia (7.25%) was highest which was isolated from all the tissues. The samples collected during the monsoon harbored more endophytes and showed higher species richness than the samples obtained in summer season. Of the total isolates, 15 isolates (21.74%) displayed antimicrobial activity, inhibiting at least one of the test microorganisms that comprised of pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhi, Pseudomonas fluorescens, Shigella dysentriae) and fungi (Trichophyton rubrum, Aspergillus fumigatus, Trichophyton sp). The results provided promising baseline information on the endophytic fungal diversity associated with I. carnea tissues and their potential exploitation as antimicrobial agents.

Unraveling the antifungal activity of a South American rattlesnake toxin crotamine

Crotamine is a highly basic peptide from the venom of Crotalus durissus terrificus rattlesnake. Its common gene ancestry and structural similarity with the β-defensins, mainly due to an identical disulfide bond pattern, stimulated us to assess the antimicrobial properties of native, recombinant, and chemically synthesized crotamine. Antimicrobial activities against standard strains and clinical isolates were analyzed by the colorimetric microdilution method showing a weak antibacterial activity against both Gram-positive and Gram-negative bacteria [MIC (Minimum Inhibitory Concentration) of 50->200 μg/mL], with the exception of Micrococcus luteus [MIC ranging from 1 to 2 μg/mL]. No detectable activity was observed for the filamentous fungus Aspergillus fumigatus and Trichophyton rubrum at concentrations up to 125 μg/mL. However, a pronounced antifungal activity against Candida spp., Trichosporon spp., and Cryptococcus neoformans [12.5-50.0 μg/mL] was observed. Chemically produced synthetic crotamine in general displayed MIC values similar to those observed for native crotamine, whereas recombinant crotamine was overridingly more potent in most assays. On the other hand, derived short linear peptides were not very effective apart from a few exceptions. Pronounced ultrastructure alteration in Candida albicans elicited by crotamine was observed by electron microscopy analyses. The peculiar specificity for highly proliferating cells was confirmed here showing potential low cytotoxic effect of crotamine against nontumoral mammal cell lines (HEK293, PC12, and primary culture astrocyte cells) compared to tumoral B16F10 cells, and no hemolytic activity was observed. Taken together these results suggest that, at low concentration, crotamine is a potentially valuable anti-yeast or candicidal agent, with low harmful effects on normal mammal cells, justifying further studies on its mechanisms of action aiming medical and industrial applications.

Screening of various extracts of Gymnema sylvestre (Retz.) R.Br. ex Schult. for antimicrobial activity

Rising appearance of resistance to the presently existing antibiotics has necessitated sustained search for new antimicrobial compounds. The present study was designed to confirm ethno-medicinal assert of Gymnema sylvestre possessing antimicrobial activity that could be a superior alternative for synthetic antimicrobial agents, if proved to be successful enough. For this, the antimicrobial properties of G. sylvestre were tested against seven bacteria (Shigella flexneri, Staphylococcus aureus, Salmonella typhi,Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, and Enterobacter aerogenes) and three fungi (Aspergillus niger, Candida albicans, and Trichophyton rubrum)by using different solvents like petroleum ether, chloroform, benzene, ethyl acetate, ethanol and distilled water. The result showed that all the solvent extracts exhibited considerable activity against the tested microorganisms. The antibacterial activity increased with the increasing concentration of the extract. Petroleum ether solvent extract of G. sytvestre is less active against all test microorganisms than five other solvent extracts, and distilled water extract is highly active against all test microorganisms. All solvent extracts at lower concentration of 50 mg/ 20 disc showed very smaller amount of activity against all test microorganisms. Key words: Gymnema sylvestre, antibacterial activity, bacterial infections, medicinal plant.

Antifungal Activity of the Essential Oils of Callitris neocaledonica and C. sulcata Heartwood (Cupressaceae)

Mortality due to fungal infections has increased substantially, becoming a worldwide problem in public health. As a contribution to the discovery of new antifungal agents, the properties of the heartwood essential oils of two trees growing in New Caledonia, Callitris neocaledonica and C. sulcata (Cupressaceae) were investigated. The essential oils extracted by hydrodistillation were characterized by GC-FID and GC/MS analyses. From C. neocaledonica oil, 31 constituents were identified, representing 97.0% of the total oil composition, which was mainly constituted by oxygenated sesquiterpenes (88%). Among them, guaiol (1; 30.2%), bulnesol (2; 12.5%), α-eudesmol (3; 10.5%), β-eudesmol (4; 10.5%), γ-eudesmol (10.2%), and elemol (4.9%) predominated. The chemical composition of C. sulcata oil, from which 39 constituents were identified (96.8% of the total oil composition), showed some similarities with that of C. neocaledonica oil. The major constituents were also oxygenated sesquiterpenes, accounting for 78.5% of the oil, amongst them, mainly compounds 1 (16.1%), 3 and 4 (9.7% each), as well as 2 (7.4%). The antifungal activity of the oils against clinical isolates of four dermatophytic fungi (Trichophyton mentagrophytes, T. rubrum, Microsporum canis, and M. gypseum) and six yeasts (Candida albicans, C. parapsilosis, C. glabrata, C. krusei, Cryptococcus neoformans, and Cryptococcus gattii) was tested by determining minimum inhibitory concentrations (MICs) using the microdilution method. The best antifungal activities of the C. neocaledonica and C. sulcata oils were obtained against C. krusei (MICs of 3.9 and 0.975 μg/ml, resp.). These MIC values were similar to those of the reference drugs itraconazole and fluconazole (1.0 and 0.5 mg/ml, resp.). The oils were also subjected to a screening for their possible DPPH(.) (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity. C. neocaledonica essential oil was more active than C. sulcata oil (93.3 vs. 32.2% DPPH(.) scavenged at 250 μg/ml).

Therapeutic Effects of Essential Oil from Waste Leaves of <i>Psidium guajava</i> L. against Cosmetic Embarrassment Using Phylogenetic Approach

Medicinal plants are facing threats due to loss of habitat and overexploitation of knows species. Therefore the present work shows utilization of essential oil from discarded leaves of Psidium guajava Linn. against human dermatophytic fungi Trichophyton rubrum, T. mentagrophytes, Trichophyton violaceum, Trichophyton tonsurans, Epidermophyton floccosum, Microsporum gypseum and Microsporum canis. The oil was found to be fungicidal at 3.0 μl/ml and it tolerated heavy inoculum of pathogens at fungicidal concentrations. The fungicidal activity of the oil was thermostable, up to 70°C and shelf life was found to be six months, which was maximum the time taken into consideration. The oil having cineole, caryophyllane, copaene, azulene and eucalyptol as main constituents, exhibited broad fungicidal activity. The oil did not show any adverse effect on mammalian skin upto 5% concentration. Phylogeny of the dermatophytes with respect to toxicity of the oil has also been discussed using molecular data. The cost effective formulation from waste leaves can be exploited after undergoing double blind successful multicentral topical testing.

In vitro fungistatic effects of natural coniferous resin from Norway spruce (Picea abies)

Resins (rosin, pitch) are natural products of the coniferous trees and are antimicrobial against a wide range of microbes. The antifungal effectiveness of resin, purified from Norway spruce (Picea abies), was studied against human pathogenic fungi and yeasts with the agar plate diffusion tests and electron microscopy (EM). The fungistatic effect of these resin mixtures (resin salves) was tested against a set of Candida yeasts, dermatophytes, and opportunistic fungi. Transmission and scanning EM was done from samples of fungi (Trichophyton mentagrophytes). In agar diffusion tests, the resin was strongly antifungal against all dermatophytes tested, e.g., against all fungi of the genus Trichophyton, but it was not antifungal against the Candida yeasts or against the opportunistic fungi tested. According to EM, resin caused damages in the cell hyphae and cell wall structures. We conclude that, in the agar plate diffusion test, coniferous resins are strongly fungistatic against the dermatophytic fungi only.

Assessment of antimicrobial, insecticidal and genotoxic effects of Melia azedarach L. (chinaberry) naturalized in Anatolia

In this study, antibacterial, antifungal, insecticidal and genotoxic activities of the fruit and leaf extracts of Melia azedarach of Turkish origin were evaluated for the first time. The antimicrobial activity was assessed against Gram (+) and ( − ) bacteria, four Candida species and three dermatophytic fungus (Trichophyton rubrum, Epidermophyton floccosum and Microsporum gypseum). The insecticidal activity of the methanolic fruit extract was performed against the larvae of Aedes aegpyti, Culex pipiens and Culex quinquefasciatus. The genotoxicity of this extract was evaluated against Drosophila melanogaster by somatic mutation and recombination test. The extracts showed higher antibacterial effect against Gram ( − ) strains (16–32 μg ml− 1 of minimal inhibition concentration, MIC), while the leaf extracts were more effective on Candida albicans (32 μg ml− 1 of MIC). The extracts did not exhibit insecticidal activity and genotoxicity. Total phenol and flavonoid contents of the extracts were determined spectrophotometrically, and the ethyl acetate extract of the leaves was the richest in total flavonoids.

Antimicrobial activity of Paenibacillus kribbensis POC 115 against the dermatophyte Trichophyton rubrum

In a search for an antifungal substance with activity against the dermatophyte fungus Trichophyton rubrum, strain POC 115 was chosen among different Paenibacillus strains for its phenotypic and genetic characterization and for preliminary characterization of its antimicrobial substance. Strain POC 115 was identified as belonging to Paenibacillus kribbensis. Physico-chemical characterization of the antimicrobial substance showed that it was not stable during heat and organic solvents treatments, but its activity was preserved at a wide range of pH and after treatment with pronase E, trypsin and DNase I. The crude concentrated supernatant of POC 115 culture was partially purified and the fraction presenting antimicrobial activity was further analyzed by UPLC/Mass Spectrometry. Two peaks were observed at 2.02 (mass 1,207 D) and 2.71 (mass 1,014 D) min in the mass chromatogram. The antimicrobial substance produced by POC 115 was correlated to iturin family compounds based on a set of primers designed for the amplification of PKS operon in the POC 115 genome. As happens with the mode of action of the antibiotics of the iturin group, the AMS produced by POC 115 caused the disruption of cytoplasmic membrane of T. rubrum and the subsequent withdraw of the intracellular material. This is the first report on the production of antimicrobial substances in P. kribbensis, and it may be of great relevance as an alternative or supplementary substance to antifungal drugs currently used against dermatophytes.