RESUMEN

Extracellular phospholipase (EPL) plays an important role in the pathogenesis of the yeast Malassezia pachydermatis. Currently, the attention of researchers is focused on studying the virulence factors involved in this process and searching solutions to reduce their activity. One of the options is the use of natural remedies as anti-virulence agents. This study is aimed at investigating the production of extracellular phospholipase in M. pachydermatis strains (18 samples) and followed by the time-dependent inhibitory effect of selected azole antifungals (itraconazole, posaconazole and voriconazole) and plant essential oil components (terpinen-4-ol, thymol, carvacrol, eugenol and geraniol), evaluated by Egg Yolk Agar plate method. Almost all strains (17 isolates, (94.4%) were found to be intense EPL producers. A significant, time-dependent inhibition of EPL was noted after 1-, 3- and 6-h exposure of Malassezia cells to itraconazole (26.4%, 47.2% and 50.9%, respectively) compared to exposure to posaconazole (26.4%, 28.3% and 28.3%, respectively) and voriconazole (18.8%, 20.8% and 35.8%, respectively). After one-hour exposure to plant essential oil components, the best inhibitory effect was recorded for eugenol (62.3%), followed by terpinen-4-ol and thymol (56.6%), geraniol (41.5%) and carvacrol (26.4%). A 3-h exposure revealed that thymol retained the best inhibitory effect (88.7%) on EPL production, followed by carvacrol (73.6%), eugenol (56.6%), terpinen-4-ol (52.8%) and geraniol (49.1%). After 6-h exposure, no growth of M. pachydermatis strains exposed to carvacrol was observed, and the inhibitory efficiency for the other tested essential oil (EO) components achieved 88.7%. The obtained results indicate the promising efficacy of plant essential oils components in the inhibition of virulence factors such as EPL production.

RESUMEN

Worldwide, the number of infections caused by biofilm-forming fungal pathogens is very high. In human medicine, there is an increasing proportion of immunocompromised patients with prolonged hospitalization, and patients with long-term inserted drains, cannulas, catheters, tubes, or other artificial devices, that exhibit a predisposition for colonization by biofilm-forming yeasts. A high percentage of mortality is due to candidemia caused by medically important Candida species. Species of major clinical significance include C. albicans, C. glabrata, C. tropicalis, C. parapsilosis, C. krusei, and C. auris. The association of these pathogenic species in the biofilm structure is a serious therapeutic problem. Candida cells growing in the form of a biofilm are able to resist persistent therapy thanks to a combination of their protective mechanisms and their ability to disseminate to other parts of the body, thus representing a threat from the perspective of a permanent source of infection. The elucidation of the key mechanisms of biofilm formation is essential to progress in the understanding and treatment of invasive Candida infections.

RESUMEN

The yeast Malassezia pachydermatis, an opportunistic pathogen that inhabits the skin of various domestic and wild animals, is capable of producing a biofilm that plays an important role in antifungal resistance. The aim of this research study was to find the intensity of biofilm production by M. pachydermatis strains isolated from the ear canal of healthy dogs, and to determine the susceptibility of planktonic, adhered and biofilm-forming cells to three azole antifungals-itraco-nazole, voriconazole and posaconazole-that are most commonly used to treat Malassezia infections. Out of 52 isolates, 43 M. pachydermatis strains (82.7%) were biofilm producers with varying levels of intensity. For planktonic cells, the minimum inhibitory concentration (MIC) range was 0.125-2 µg/mL for itraconazole, 0.03-1 µg/mL for voriconazole and 0.03-0.25 µg/mL for posaconazole. Only two isolates (4.7%) were resistant to itraconazole, one strain (2.3%) to voriconazole and none to posaconazole. For adhered cells and the mature biofilm, the following MIC ranges were found: 0.25-16 µg/mL and 4-16 µg/mL for itraconazole, 0.125-8 µg/mL and 0.25-26 µg/mL for voriconazole, and 0.03-4 µg/mL and 0.25-16 µg/mL for posaconazole, respectively. The least resistance for adhered cells was observed for posaconazole (55.8%), followed by voriconazole (62.8%) and itraconazole (88.4%). The mature biofilm of M. pachydermatis showed 100% resistance to itraconazole, 95.3% to posaconazole and 83.7% to voriconazole. The results of this study show that higher concentrations of commonly used antifungal agents are needed to control infections caused by biofilm-forming strains of M. pachydermatis.

RESUMEN

Fungal skin diseases are well-recognized diseases with public health implications. The study provides a comprehensive overview and aims to determine the rate of positive fungal cultures to identify the most common fungal species in guinea pigs and rabbits and to determine the rate of asymptomatic carriers in healthy pet animals. This knowledge is essential for understanding disease transmission dynamics and epidemiological situation problems. A total of 167 animals (64 rabbits and 103 guinea pigs) were investigated in this study. The fungi of the genus Penicillium, Rhizopus, Mucor, Cladosporium, and Aspergillus were the most common in the examined animals, and they were isolated from 162 (97%) of the animals enrolled. No fungal growth was observed in 5 animals. In 15 cases (8.98%), we found pathogenic zoonotic dermatophytes (Trichophyton mentagrophytes), which caused several health problems in two humans in contact with affected animals. This study presents the prevalence of fungal flora in pet guinea pigs and rabbits in Slovakia.

RESUMEN

INTRODUCTION: Fusaria are microscopic filamentous fungi which are spread in soil, in various organic substrates, and include more than 80 phytopathogenic species which are predominantly hosted by cereals, fruits and vegetables. Many of these species, under certain conditions, are capable of synthesizing secondary metabolites, mycotoxins. At present, various substances are used for their elimination and one of the solutions appears to be essential oils. In the presented study, the antifungal activity of essential oils was researched in vitro. MATERIAL AND METHODS: In this study, two standard fungal isolates Fusarium graminearum CCM F-683 and Fusarium graminearum CCM 8244 (Brno, Czech Republic) were used. The antifungal effect of 6 tested essential oils (Syzygium aromaticum, Origanum vulgare, Thymus vulgaris, Hyssopus officinalis , Ocimum basilicum, Myristica fragrans) was determined using the broth microdilution method, which allows reading of the MIC (minimum inhibitory concentration). According to the results obtained, the growth inhibition of Fusarium graminearum was determined by assay for the inhibition of radial growth of the mycelium. RESULTS: The inhibitory effects of thymus, oregano, basil, myristica, hyssop and syzygium essential oil (EO) on mycelial growth of Fusarium graminearum CCM F-683 and CCM 8244 were investigated. The best antifungal activity against the both strains of Fusarium graminearum (37.4%; 40.7%) was demonstrated by Origanum vulgare EO at the concentration 100 µg/mL. Among the four tested oils, three (Syzygium aromaticum, Thymus vulgaris, Origanum vulgare) achieved the best inhibitory effect (100%) at concentrations 500 µg/mL and 1000 µg/mL. CONCLUSIONS: In the protection of plants against pathogenic fungi, essential oils appear to be a suitable substitute for synthetic chemicals.

Asunto(s)

RESUMEN

INTRODUCTION: The virulence of Candida albicans is conditioned by several virulence factors, one of which is the formation of biofilm which reduces the sensitivity of the yeast to conventional antimycotics. This study determines the antifungal and antibiofilm activity of five essential oils (EOs) of the Lamiaceae family: Salvia officinalis, Thymus vulgaris, Rosmarinus officinalis, Origanum vulgare, and Hyssopus officinalis. MATERIAL AND METHODS: In the preliminary research, the antifungal effect of eachof the EOs was tested in the concentration range of 200-0.4 mg/mL on planktonic Candida albicans (C. albicans) cells. A total of 13 C. albicans clinical isolates and one reference strain were evaluated on biofilm formation. RESULTS: Nine isolates (69.2%) showed weak biofilm production and four strains (30.8%) were detected as moderate biofilm producers. The EOs of Thymus vulgaris and Origanum vulgare were seen as effective antifungal agents on planktonic cells with the MIC 0.4 mg/mL. The highest average MIC values were recorded in Salvia officinalis EO (24.0 and 14.8 mg/mL). All isolates were used to determine EOs efficacy on the inhibition of adherence phase and biofilm formation. The biofilm production of C. albicans after exposition by EOs was quantitatively examined by crystal violet dye. CONCLUSIONS: The most effective for adherence phase and biofilm formation were EOs of Origanum vulgare (0.1 mg/mL and 0.3 mg/mL) and Thymus vulgaris (0.1 mg/mL and 0.4 mg/mL). The obtained results show that EOs of Thymus vulgaris and Origanum vulgare are potential agents for antifungal treatment or prophylaxis by reducing the resistance of pathogen.

Asunto(s)

RESUMEN

Nowadays the treatment of fungal infections is difficult due to increasing resistance of fungal pathogens to antimycotics. The efficacy of antimycotics can be increased by a proper combination of commercial drugs and natural substances. The 100% antimycotic activity was found using susceptibility testing of Candida albicans yeasts on clotrimazole alone and in combination with tea tree oil, or with a multicomponent preparation containing cannabis oil and various essential oils and in combination with propolis tincture. Combination of natural substances with fluconazole seems to be also prospective. Fluconazole alone achieved an antifungal activity of 80.95% but natural active substances increased its efficacy by 9.55-14.25%.Key words: Candida albicans fluconazole clotrimazole natural active substances synergism.

Asunto(s)

RESUMEN

Malassezia (M.) pachydermatis is the lipophilic yeast, which is normally present on the skin and in the ear canal of dogs but under certain conditions it may cause dermatitis and otitis. There is less known about the occurrence of lipid-dependent Malassezia species in dogs. The aim of this study was to detect whether lipid-dependent yeasts are part of the normal microflora in dogs. Two groups of animals were selected for comparison. The group of healthy dogs contained samples of 118 individuals and the group of dogs with cutaneous lesions or otitis externa comprised 328 dogs. The isolates of Malassezia were identified by using genotypic methods that allow the precise identification. M. pachydermatis was the most frequently isolated species in this study (121 isolates). Only four isolates were identified as M. furfur and one isolate was identified as M. nana.

Asunto(s)

RESUMEN

This contribution provides an overview of literature data on the microbial binding and biodegradation of mycotoxins. These data and preliminary results from our own laboratory suggest that mycotoxin-bacterial binding or biodegradation is a realistic process and encourages the screening of bacterial strains and their biodegradation potential.

Asunto(s)