Search Results (96)

Dermatophytoses are infectious skin diseases of public health importance because of their transmissibility and high prevalence, especially among children. This is the first study aiming to estimate and report the burden of dermatophytoses on school-age children on the island of Santiago in Cape Verde, an African country that is an archipelago. A total of 249 students attending the afternoon shift of three elementary schools in the city of Achada Igreja were examined. Of these, 60 had suspected lesions of dermatophyte infection. However, from the samples collected from these 60 students, including hair, nails, and skin scrapings, only 18 dermatophyte isolates were obtained, corresponding to a point prevalence of 7.2%. Morphological species identification demonstrated three different species: Trichophyton soudanense, Trichophyton rubrum, and Trichophyton violaceum; re-identification by sequencing the internal transcribed spacer (ITS) 1 and 2 regions of ribosomal DNA, and the 5.8S rDNA encoding gene (ITS-5.8S region), revealed T. soudanense as the most prevalent species, with only one case of T. rubrum. This is the first epidemiological data describing dermatophytoses and dermatophytes in Cape Verde among school-age children on one of the archipelago islands. It reinforces the need of using culture and accurate identification methodologies when gathering epidemiological data on dermatophytoses. Full article

Dermatophytosis in cattle is most often caused by infection with Trichophyton verrucosum (T. verrucosum), but also with Trichophyton rubrum (T. rubrum), Trichophyton mentagrophytes (T. mentagrophytes) and others, regardless of the geographical zone. The infection is transmitted through direct contact between animals as well as infected environmental elements. The human-to-human transmission of fungal infection is also possible.. This retrospective study was conducted based on a detailed analysis of the results of the mycological examination and medical documentation of 40 patients from Greater Poland, diagnosed with cattle-to-human dermatophytoses from March 2017 to November 2023. T. verrucosum accounted for 97.5% of infections and T. mentagrophytes for 2.5%; no other species of dermatophytes from cattle were found. Superficial skin mycosis in humans associated with cattle was more often diagnosed in small children and men directly engaged in cattle breeding. The dominant etiological factor of the superficial fungal skin infection was T. verrucosum, which mainly affected the scalp in children and upper limbs in adult men. In relation to the cattle population in Greater Poland, the number of cases of superficial skin mycoses among cattle breeders and their family members over the period of more than six and a half years of observation does not seem to be high. Full article

Onychomycosis is a common fungal infection that affects the nails and accounts for approximately 50% of all nail diseases. The main pathogens involved include dermatophytes, such as Trichophyton rubrum, members of the T. mentagrophytes complex, and emerging pathogens in this infection, T. schoenleinii and T. tonsurans. Tea tree (Melaleuca alternifolia Cheel) essential oil (EO) has been proposed as a promising natural alternative to traditional treatments due to its antimicrobial properties. Among its more than 100 compounds, terpinen-4-ol is one of the main contributors to the antifungal action of this EO. To determine the antifungal activity of tea tree EO against dermatophytes, we designed an in vitro study using EUCAST-AFST protocols to obtain the values of MIC (minimum inhibitory concentration) and MFC (minimum fungicidal concentration) of several commercial M. alternifolia Cheel EOs against three species of dermatophytes isolated from clinical samples with suspected toenail onychomycosis. The results showed that the microorganism most sensitive to the action of the EO was T. rubrum, which had an MIC value more than 13 times lower than the value obtained for T. schoenleinii (0.4% v/v), the most resistant isolate. No differences in antifungal activity were observed by the analysed EOs or between the MIC and MFC values. These in vitro results suggest that tea tree EO is a viable option for the alternative treatment of onychomycosis, although clinical studies are needed to confirm the long-term antifungal activity, safety and efficacy of the oils studied in a clinical context. Full article

Onychomycosis is a recalcitrant fungal infection of the nail unit that can lead to secondary infections and foot complications. Accurate pathogen identification by confirmatory testing is recommended to improve treatment outcomes. In this study, we reviewed the records of 710,541 patients whose nail specimens were sent to a single molecular diagnostic laboratory between 2015 and 2024. PCR testing revealed a more comprehensive spectrum of pathogens than previously reported, which was corroborated by the demonstration of fungal invasion on histopathology. Consistent with our current understanding, the T. rubrum complex (54.3%) are among the most common pathogens; however, a significant portion of mycology-confirmed diagnoses were caused by the T. mentagrophytes complex (6.5%), Aspergillus (7.0%) and Fusarium (4.5%). Females were significantly more likely to be infected with non-dermatophytes molds (NDMs; OR: 2.0), including Aspergillus (OR: 3.3) and Fusarium (OR: 2.0), and yeasts (OR: 1.5), including Candida albicans (OR: 2.0) and C. parapsilosis (OR 1.6), than males. The T. mentagrophytes complex became more prevalent with age, and conversely the T. rubrum complex became less prevalent with age. Patients aged ≥65 years also demonstrated a higher likelihood of contracting onychomycosis caused by NDMs (OR: 1.6), including Aspergillus (OR: 2.2), Acremonium (OR: 3.5), Scopulariopsis (OR: 2.9), Neoscytalidium (OR: 3.8), and yeasts (OR: 1.8), including C. albicans (OR: 1.9) and C. parapsilosis (OR: 1.7), than young adults. NDMs (e.g., Aspergillus and Fusarium) and yeasts were, overall, more likely to cause superficial onychomycosis and less likely to cause dystrophic onychomycosis than dermatophytes. With regards to subungual onychomycosis, Aspergillus, Scopulariopsis and Neoscytalidium had a similar likelihood as dermatophytes. The advent of molecular diagnostics enabling a timely and accurate pathogen identification can better inform healthcare providers of appropriate treatment selections and develop evidence-based recommendations. Full article

Introduction: Efinaconazole 10% topical solution labeling for onychomycosis describes phase III trials of 12 months of treatment; the slow growth of onychomycotic nails suggests a longer treatment period may increase efficacy. We present here the first evaluation of extended use of efinaconazole 10% topical solution for up to 24 months. Materials and Methods: Enrolled patients (n = 101) had one target great toenail with mild to moderate distal lateral subungual onychomycosis and applied efinaconazole 10% topical solution to all affected toenails once daily for 18 months (EFN18) or 24 months (EFN24). Efficacy and safety were evaluated at each visit by visual review and mycology sampling. Results: Regarding the target toenail for patients treated for 24 months (EFN24), mycological cure (negative microscopy and culture) was 66.0% at Month 12, increasing to 71.7% at Month 24; effective cure (mycological cure and ≤10% affected nail) was 13.2% at Month 12, rising to 22.6% at Month 24. Mild to moderate application site reactions (symptoms of erythema/scaling) were the only efinaconazole-related reactions, in eight patients (7.9%). No systemic efinaconazole events or drug interactions were found. Patients aged 70 years or more had similar efficacy to younger patients at all time periods and did not show any increased treatment risks. Thinner nails exhibited better clearance versus thicker nails. A higher proportion of patients with Trichophyton mentagrophytes complex infection experienced application site reactions (35.7%), and a higher effective cure was found at Month 24 versus T. rubrum patients. Conclusion: There is a trend of increasing mycological cure and effective cure beyond Month 12 to Month 24, without an increased safety risk. The enrolled population in this trial was significantly older than in the phase III trials, with a greater degree of onychomycosis severity; however, increased age did not appear to reduce the chance of efficacy to Month 24 in this study. Our data suggest that lack of ability to clear nail dystrophy remains a significant problem for patients, rather than any lack of efinaconazole action over long-term treatment periods. Full article

Microbial infections pose a significant global health threat, affecting millions of individuals and leading to substantial mortality rates. The increasing resistance of microorganisms to conventional treatments requires the development of novel antimicrobial agents. Pyrroloquinoline quinone (PQQ), a natural medicinal drug involved in various cellular processes, holds promise as a potential antimicrobial agent. In the present study, our aim was, for the first time, to explore the antimicrobial activity of PQQ against 29 pathogenic microbes, including 13 fungal strains, 8 Gram-positive bacteria, and 8 Gram-negative bacteria. Our findings revealed potent antifungal properties of PQQ, particularly against Syncephalastrum racemosum, Talaromyces marneffei, Candida lipolytica, and Trichophyton rubrum. The MIC values varied between fungal strains, and T. marneffei exhibited a lower MIC, indicating a greater susceptibility to PQQ. In addition, PQQ exhibited notable antibacterial activity against Gram-positive and -negative bacteria, with a prominent inhibition observed against Staphylococcus epidermidis, Proteus vulgaris, and MRSA strains. Remarkably, PQQ demonstrated considerable biofilm inhibition against the MRSA, S. epidermidis, and P. vulgaris strains. Transmission electron microscopy (TEM) studies revealed that PQQ caused structural damage and disrupted cell metabolism in bacterial cells, leading to aberrant morphology, compromised cell membrane integrity, and leakage of cytoplasmic contents. These findings were further affirmed by shotgun proteomic analysis, which revealed that PQQ targets several important cellular processes in bacteria, including membrane proteins, ATP metabolic processes, DNA repair processes, metal-binding proteins, and stress response. Finally, detailed molecular modeling investigations indicated that PQQ exhibits a substantial binding affinity score for key microbial targets, including the mannoprotein Mp1P, the transcriptional regulator TcaR, and the endonuclease PvuRTs1I. Taken together, our study underscores the effectiveness of PQQ as a broad-spectrum antimicrobial agent capable of combating pathogenic fungi and bacteria, while also inhibiting biofilm formation and targeting several critical biological processes, making it a promising therapeutic option for biofilm-related infections. Full article

Tinea cruris, a dermatophyte fungal infection predominantly caused by Trichophyton rubrum and Epidermophyton floccosum, primarily affects the groin, pubic region, and adjacent thigh. Its recurrence is frequent, attributable to repeated fungal infections in susceptible individuals, especially those with onychomycosis or tinea pedis, which act as reservoirs for dermatophytes. Given the persistent nature of tinea cruris, vaccination emerges as a promising strategy for fungal infection management, offering targeted, durable protection against various fungal species. Vaccines stimulate both humoral and cell-mediated immunity and are administered prophylactically to prevent infections while minimizing the risk of antifungal resistance development. Developing fungal vaccines is challenging due to the thick fungal cell wall, similarities between fungal and human cells, antigenic variation, and evolutionary resemblance to animals, complicating non-toxic target identification and T-cell response variability. No prior research has shown an mRNA vaccine for T. rubrum. Hence, this study proposes a novel mRNA-based vaccine for tinea cruris, potentially offering long-term immunity and reducing reliance on antifungal medications. This study explores the complete proteome of T. rubrum, identifying potential protein candidates for vaccine development through reverse vaccinology. Immunogenic epitopes from these candidates were mapped and integrated into multitope vaccines and reverse translated to construct mRNA vaccines. Then, the mRNA was translated and computationally assessed for physicochemical, chemical, and immunological attributes. Notably, 1,3-beta-glucanosyltransferase, CFEM domain-containing protein, cell wall galactomannoprotein, and LysM domain-containing protein emerged as promising vaccine targets. Antigenic, immunogenic, non-toxic, and non-allergenic cytotoxic T lymphocyte, helper T lymphocyte, and B lymphocyte epitopes were selected and linked with appropriate linkers and Toll-like receptor (TLR) agonist adjuvants to formulate vaccine candidates targeting T. rubrum. The protein-based vaccines underwent reverse translation to construct the mRNA vaccines, which, after inoculation, were translated again by host ribosomes to work as potential components for triggering the immune response. After that, molecular docking, normal mode analysis, and molecular dynamic simulation confirmed strong binding affinities and stable complexes between vaccines and TLR receptors. Furthermore, immune simulations of vaccines with and without adjuvant demonstrated activation of immune responses, evidenced by elevated levels of IgG1, IgG2, IgM antibodies, cytokines, and interleukins. There was no significant change in antibody production between vaccines with and without adjuvants, but adjuvants are crucial for activating the innate immune response via TLRs. Although mRNA vaccines hold promise against fungal infections, further research is essential to assess their safety and efficacy. Experimental validation is crucial for evaluating their immunogenicity, effectiveness, and safety. Full article

Lignin nanoparticles emerged as a promising alternative for drug delivery systems owing to their biodegradability and bioactive properties. This study investigated the antimicrobial activity of the ethanolic extract of Ocimum basilicum-loaded lignin nanoparticles (OB-LNPs) and Lagenaria siceraria seed oil-loaded lignin nanoparticles (LS-LNPs) to find a solution for antimicrobial resistance. OB-LNPs and LS-LNPs were tested for their antimicrobial potential against Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella enterica, Trichophyton mentagrophytes, Trichophyton rubrum, and Microsporum canis. OB-LNPs and LS-LNPs were further tested for their anti-efflux activity against ciprofloxacin-resistant Salmonella enterica strains and for treating Salmonella infection in a rat model. We also investigated the antifungal efficacy of OB-LNPs and LS-LNPs for treating T. rubrum infection in a guinea pig model. Both OB-LNPs and LS-LNPs showed strong antimicrobial potential against S. Typhimurium and T. rubrum infections. LS-LNPs showed antibacterial activity against Salmonella enterica species with a MIC range of 0.5–4 µg/mL and antifungal activity against T. rubrum with a MIC range of 0.125–1 µg/mL. OB-LNPs showed antibacterial activity against Salmonella enterica species with a MIC range of 0.5–2 µg/mL and antifungal activity against T. rubrum with a MIC range of 0.25–2 µg/mL. OB-LNPs and LS-LNPs downregulated the expression of ramA and acrB efflux pump genes (fold change values ranged from 0.2989 to 0.5434; 0.4601 to 0.4730 for ramA and 0.3842–0.6199; 0.5035–0.8351 for acrB). Oral administration of OB-LNPs and LS-LNPs in combination with ciprofloxacin had a significant effect on all blood parameters, as well as on liver and kidney function parameters. Oxidative stress mediators, total antioxidant capacity, and malondialdehyde were abolished by oral administration of OB-LNPs and LS-LNPs (0.5 mL/rat once daily for 5 days). Interferon-γ and tumor necrosis factor-α were also reduced in comparison with the positive control group and the ciprofloxacin-treated group. Histopathological examination of the liver and intestine of OB-LNPs and LS-LNPs-treated rats revealed an elevation in Salmonella clearance. Treatment of T. rubrum-infected guinea pigs with OB-LNPs and LS-LNPs topically in combination with itraconazole resulted in a reduction in lesion scores, microscopy, and culture results. In conclusion, OB-LNPs and LS-LNPs possess immunomodulatory and antioxidant potential and can be used as naturally derived nanoparticles for drug delivery and treatment of Salmonellosis and dermatophytosis infections. Full article

The essential oil of Aniba canelilla (Kunth) Mez (EOAC), an Amazon plant composed of a rare nitro compound, has shown scientific evidence of antifungal activity but is still unexplored against dermatophytes. The antifungal susceptibility of EOAC and its main compound, 1-nitro-2-phenylethane (NP), was evaluated against dermatophytes (Trichophyton rubrum, T. mentagrophytes and Microsporum canis), evidencing antifungal activity with an inhibitory concentration lower than 256 μg/mL. The mechanism of action was also evaluated, and it is suggested that EOAC and NP have fungicidal action in the fungal membrane, since the antifungal activity occurs through a modification of the shape of the conidial structures of the fungus, showing the permeability of the intracellular content due to the visually observed plasmolysis and cytosolic extravasation through an osmotic process. These results suggest the essential oil and its main compound are promising plant-derived alternatives for treating ungual dermatophytosis. Full article

Onychomycoses are nail infections that require prolonged therapy and have high recurrence rates. Dermatophytes are the main etiological agents of these infections, followed by yeasts and non-dermatophyte filamentous fungi. The limited antifungal arsenal used to treat onychomycosis and the change in the susceptibility profile of these agents contribute to the chronicity and recalcitrant profile of infections. The present study aimed to determine the antifungal activity of extracts obtained from pure and mixed cultures of Candida parapsilosis, Trichophyton mentagrophytes, and Trichophyton rubrum. Additionally, in vivo toxicity tests with Galleria mellonella and time-kill assays were carried out. The susceptibility profiles of dermatophytes were determined using a microdilution technique with minimum inhibitory concentrations (MICs) between 250 and 8000 µg/mL. The time-kill assay, compared to growth control, resulted in the death of dermatophytes within 48 h. No toxicity of the extracts was detected in experiments with Galleria mellonella larvae under the test conditions. The extracts of pure and mixed cultures of Candida parapsilosis and dermatophytes present antifungal activity against T. mentagrophytes and T. rubrum. Isolating and identifying compounds in the extracts may allow the development of new therapeutic approaches to control fungal infections. Full article

This study presents the synthesis of four series of novel hybrid chalcones (20,21)a–g and (23,24)a–g and six series of 1,3,5-triazine-based pyrimido[4,5-b][1,4]diazepines (28–33)a–g and the evaluation of their anticancer, antibacterial, antifungal, and cytotoxic properties. Chalcones 20b,d, 21a,b,d, 23a,d–g, 24a–g and the pyrimido[4,5-b][1,4]diazepines 29e,g, 30g, 31a,b,e–g, 33a,b,e–g exhibited outstanding anticancer activity against a panel of 60 cancer cell lines with GI₅₀ values between 0.01 and 100 μM and LC₅₀ values in the range of 4.09 μM to >100 μM, several of such derivatives showing higher activity than the standard drug 5-fluorouracil (5-FU). On the other hand, among the synthesized compounds, the best antibacterial properties against N. gonorrhoeae, S. aureus (ATCC 43300), and M. tuberculosis were exhibited by the pyrimido[4,5-b][1,4]diazepines (MICs: 0.25–62.5 µg/mL). The antifungal activity studies showed that triazinylamino-chalcone 29e and triazinyloxy-chalcone 31g were the most active compounds against T. rubrum and T. mentagrophytes and A. fumigatus, respectively (MICs = 62.5 μg/mL). Hemolytic activity studies and in silico toxicity analysis demonstrated that most of the compounds are safe. Full article

Dermatophytes associated with bacteria can lead to severe, difficult-to-treat infections and contribute to chronic infections. Trichophyton rubrum, Staphylococcus aureus, and Staphylococcus epidermidis can form biofilms influenced by nutrient availability. This study investigated biofilm formation by these species by utilizing diverse culture media and different time points. These biofilms were studied through scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), biomass, metabolic activity, and colony-forming units (CFUs). The results revealed that mixed biofilms exhibited high biomass and metabolic activity when cultivated in the brain heart infusion (BHI) medium. Both bacterial species formed mature biofilms with T. rubrum within 72 h, irrespective of media. The timing of bacterial inoculation was pivotal in influencing biomass and metabolic activity. T. rubrum’s development within mixed biofilms depended on bacterial addition timing, while pre-adhesion influenced fungal growth. Bacterial communities prevailed initially, while fungi dominated later in the mixed biofilms. CLSM revealed 363 μm thick T. rubrum biofilms with septate, well-developed hyphae; S. aureus (177 μm) and S. epidermidis (178 μm) biofilms showed primarily cocci. Mixed biofilms matched T. rubrum’s thickness when associated with S. epidermidis (369 μm), with few hyphae initially. Understanding T. rubrum and Staphylococcal interactions in biofilms advances antimicrobial resistance and disease progression knowledge. Full article

Trichophyton rubrum is the leading causative agent of dermatophytosis worldwide. Keratinocytes are the first line of defense that drives an immune response against fungal invasion. Host-specific pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs) to trigger immunological pathways. Fungal cell wall components are the primary sources of fungal PAMPs, and some pathogens increase cell wall rearrangement to evade the immune system. Glycolysis and enhanced lactate levels are critical for improving host immune responses to fungal infections. Using reverse transcription–quantitative polymerase chain reaction (RT-qPCR), we evaluated the transcriptional responses of human genes involved in fungal recognition and glycolytic metabolism and fungal cell-wall-related genes in a co-culture model of human keratinocytes with T. rubrum. We observed the upregulation of several Toll-like receptors (TLRs), NOD-like receptors (NLRs), and glycolytic genes. Complementarily, we measured intra- and extracellular glucose levels and the increase in lactate production in the co-culture supernatant. We noted a distinct transcriptional regulation pattern of fungal cell-wall-related genes from fungal growth on keratin as the primary carbon source compared to co-culture with human keratinocytes. Our results showed new insights into the transcriptional adaptation of keratinocytes, particularly in regulating genes involved in sensing and metabolic processes, during the interaction with T. rubrum. Full article

Trichophyton rubrum is the primary causative agent of dermatophytosis worldwide. This fungus colonizes keratinized tissues and uses keratin as a nutritional source during infection. In T. rubrum–host interactions, sensing a hostile environment triggers the adaptation of its metabolic machinery to ensure its survival. The glyoxylate cycle has emerged as an alternative metabolic pathway when glucose availability is limited; this enables the conversion of simple carbon compounds into glucose via gluconeogenesis. In this study, we investigated the impact of stuA deletion on the response of glyoxylate cycle enzymes during fungal growth under varying culture conditions in conjunction with post-transcriptional regulation through alternative splicing of the genes encoding these enzymes. We revealed that the ΔstuA mutant downregulated the malate synthase and isocitrate lyase genes in a keratin-containing medium or when co-cultured with human keratinocytes. Alternative splicing of an isocitrate lyase gene yielded a new isoform. Enzymatic activity assays showed specific instances where isocitrate lyase and malate synthase activities were affected in the mutant strain compared to the wild type strain. Taken together, our results indicate a relevant balance in transcriptional regulation that has distinct effects on the enzymatic activities of malate synthase and isocitrate lyase. Full article

The increase in incidence of superficial fungal infections combined with the emergence of antifungal resistance represents both a global health challenge and a considerable economic burden. Recently, dermatophytes, the main culprit causing superficial fungal infections, have started to exhibit antifungal resistance. This can be observed in some of the most common species such as Trichophyton rubrum and Trichophyton mentagrophytes. Importantly, the new subspecies, known as Trichophyton indotineae, has been reported to show high resistance to terbinafine, a first-line treatment for dermatophyte infections. Compounding these issues is the realization that diagnosing the causative infectious agents requires using molecular analysis that goes beyond the conventional macroscopic and microscopic methods. These findings emphasize the importance of conducting antifungal susceptibility testing to select the appropriate antifungal necessary for successful treatment. Implementing these changes may improve clinical practices that combat resistant dermatophyte infections. Full article