Antifungal resistance in Superficial mycoses

Formulation and Antimycotic Evaluation of Colloidal Itraconazole-Loaded Metered Dose Sprays for Treating Superficial Mycoses

Commercial topical formulations containing itraconazole (poorly water soluble), for mycotic infections, have poor penetration to infection sites beneath the nails and skin thereby necessitating oral administration. To improve penetration, colloidal solutions of itraconazole (G1-G4) containing Poloxamer 188, tween 80, ethanol, and propylene glycol were prepared and incorporated into HFA-134-containing sprays. Formulations were characterized using particle size, drug content, and Fourier-transform infrared spectroscopy (FTIR). In vitro permeation studies were performed using Franz diffusion cells for 8 h. Antimycotic activity on Candida albicans and Trichophyton rubrum was performed using broth micro-dilution and flow cytometry, while cytotoxicity was tested on HaCaT cell lines. Particle size ranged from 39.35-116.80 nm. FTIR and drug content revealed that G1 was the most stable formulation (optimized formulation). In vitro release over 2 h was 45% for G1 and 34% for the cream. There was a twofold increase in skin permeation, fivefold intradermal retention, and a sevenfold increase in nail penetration of G1 over the cream. Minimum fungicidal concentrations (MFC) against C. albicans were 0.156 and 0.313 µg/mL for G1 and cream, respectively. The formulations showed optimum killing kinetics after 48 h. MFC values against T. rubrum were 0.312 and 0.625 µg/mL for the G1 and cream, respectively. Transmission electron microscopy revealed organelle destruction and cell leakage for G1 in both organisms and penetration of keratin layers to destroy T. rubrum. Cytotoxicity evaluation of G1 showed relative safety for skin cells. The G1 formulation showed superior skin permeation, nail penetration, and fungicidal activity compared with the cream formulation.

Topical statins as antifungals: a review

Cutaneous fungal infections affect millions around the world. However, severe, multi-resistant fungal infections are increasingly being reported over the past years. As a result of the high rate of resistance which urged for drug repurposing, statins were studied and found to have multiple pleiotropic effects, especially when combined with other already-existing drugs. An example of this is the synergism found between several typical antifungals and statins, such as antifungals Imidazole and Triazole with a wide range of statins shown in this review. The main mechanisms in which they exert an antifungal effect are ergosterol inhibition, protein prenylation, mitochondrial disruption, and morphogenesis/mating inhibition. This article discusses multiple in vitro studies that have proven the antifungal effect of systemic statins against many fungal species, whether used alone or in combination with other typical antifungals. However, as a result of the high rate of drug-drug interactions and the well-known side effects of systemic statins, topical statins have become of increasing interest. Furthermore, patients with dyslipidemia treated with systemic statins who have a new topical fungal infection could benefit from the antifungal effect of their statin. However, it is still not indicated to initiate systemic statins in patients with topical mycotic infections if they do not have another indication for statin use, which raises the interest in using topical statins for fungal infections. This article also tackles the different formulations that have been studied to enhance topical statins' efficacy, as well as the effect of different topical statins on distinct dermatologic fungal diseases.

Synergistic activity between conventional antifungals and chalcone-derived compound against dermatophyte fungi and Candida spp

The scarce antifungal arsenal, changes in the susceptibility profile of fungal agents, and lack of adherence to treatment have contributed to the increase of cases of dermatomycoses. In this context, new antimicrobial substances have gained importance. Chalcones are precursors of the flavonoid family that have multiple biological activities, have high tolerability by humans, and easy synthesis. In this study, we evaluated the in vitro antifungal activity, alone and in combination with conventional antifungal drugs, of the VS02-4'ethyl chalcone-derived compound against dermatophytes and Candida spp. Susceptibility testing was carried out by broth microdilution. Experiments for determination of the target of the compound on the fungal cell, time-kill kinetics, and toxicity tests in Galleria mellonella model were also performed. Combinatory effects were evaluated by the checkerboard method. Results showed high activity of the compound VS02-4'ethyl against dermatophytes (MIC of 7.81-31.25 μg/ml). The compound targeted the cell membrane, and the time-kill test showed the compound continues to exert gradual activity after 5 days on dermatophytes, but no significant activity on Candida. Low toxicity was observed at 250 mg/kg. Excellent results were observed in the combinatory test, where VS02-4'ethyl showed synergistic interactions with itraconazole, fluconazole, terbinafine, and griseofulvin, against all isolates tested. Although further investigation is needed, these results revealed the great potential of chalcone-derived compounds against fungal infections for which treatments are long and laborious.

Expert Panel Review of Skin and Hair Dermatophytoses in an Era of Antifungal Resistance

Dermatophytoses are fungal infections of the skin, hair, and nails that affect approximately 25% of the global population. Occlusive clothing, living in a hot humid environment, poor hygiene, proximity to animals, and crowded living conditions are important risk factors. Dermatophyte infections are named for the anatomic area they infect, and include tinea corporis, cruris, capitis, barbae, faciei, pedis, and manuum. Tinea incognito describes steroid-modified tinea. In some patients, especially those who are immunosuppressed or who have a history of corticosteroid use, dermatophyte infections may spread to involve extensive skin areas, and, in rare cases, may extend to the dermis and hair follicle. Over the past decade, dermatophytoses cases not responding to standard of care therapy have been increasingly reported. These cases are especially prevalent in the Indian subcontinent, and Trichophyton indotineae has been identified as the causative species, generating concern regarding resistance to available antifungal therapies. Antifungal-resistant dermatophyte infections have been recently recognized in the United States. Antifungal resistance is now a global health concern. When feasible, mycological confirmation before starting treatment is considered best practice. To curb antifungal-resistant infections, it is necessary for physicians to maintain a high index of suspicion for resistant dermatophyte infections coupled with antifungal stewardship efforts. Furthermore, by forging partnerships with federal agencies, state and local public health agencies, professional societies, and academic institutions, dermatologists can lead efforts to prevent the spread of antifungal-resistant dermatophytes.

The laboratory investigation, management, and infection prevention and control of Candida auris: a narrative review to inform the 2024 national guidance update in England

The emergent fungal pathogen Candida auris is increasingly recognised as an important cause of healthcare-associated infections globally. It is highly transmissible, adaptable, and persistent, resulting in an organism with significant outbreak potential that risks devastating consequences. Progress in the ability to identify C. auris in clinical specimens is encouraging, but laboratory diagnostic capacity and surveillance systems are lacking in many countries. Intrinsic resistance to commonly used antifungals, combined with the ability to rapidly acquire resistance to therapy, substantially restricts treatment options and novel agents are desperately needed. Despite this, outbreaks can be interrupted, and mortality avoided or minimised, through the application of rigorous infection prevention and control measures with an increasing evidence base. This review provides an update on epidemiology, the impact of the COVID-19 pandemic, risk factors, identification and typing, resistance profiles, treatment, detection of colonisation, and infection prevention and control measures for C. auris. This review has informed a planned 2024 update to the United Kingdom Health Security Agency (UKHSA) guidance on the laboratory investigation, management, and infection prevention and control of Candida auris. A multidisciplinary response is needed to control C. auris transmission in a healthcare setting and should emphasise outbreak preparedness and response, rapid contact tracing and isolation or cohorting of patients and staff, strict hand hygiene and other infection prevention and control measures, dedicated or single-use equipment, appropriate disinfection, and effective communication concerning patient transfers and discharge.

An update on antifungal resistance in dermatophytosis

INTRODUCTION

The reports of resistance to antifungal agents used for treating onychomycosis and other superficial fungal infections are increasing. This rise in antifungal resistance poses a public health challenge that requires attention.

AREAS COVERED

This review explores the prevalence of dermatophytes and the current relationship between dermatophyte species, their minimum inhibitory concentrations (MICs) for terbinafine (an allylamine) and itraconazole (an azole), and various mutations prevalent in these species. The most frequently isolated dermatophyte associated with resistance in patients with onychomycosis and dermatophytosis was T. mentagrophytes. However, T. indotineae emerged as the most prevalent isolate with mutations in the SQLE gene, exhibiting the highest MIC of 8 µg/ml for terbinafine and MICs of 8 µg/ml and ≥ 32 µg/ml for itraconazole.Overall, the most prevalent SQLE mutations were Phe397Leu, Leu393Phe, Ala448Thr, Phe397Leu/Ala448Thr, and Lys276Asn/Leu415Phe (relatively recent).

EXPERT OPINION

Managing dermatophyte infections requires a personalized approach. A detailed history should be obtained including details of travel, home and occupational exposure, and clinical examination of the skin, nails and other body systems. Relevant testing includes mycological examination (traditional and molecular). Additional testing, where available, includes MIC evaluation and detection of SQLE mutations. In case of suspected terbinafine resistance, itraconazole or voriconazole (less commonly) should be considered.

Evaluation of the benefit of the addition of 1% topical luliconazole versus topical bland emollient to the systemic itraconazole therapy for the management of disseminated dermatophytosis: A randomised control trial

BACKGROUND

The present epidemic of dermatophytosis in India is marked by an increase in chronic, recurrent and disseminated cases. A combination of oral itraconazole and topical luliconazole is being increasingly utilised by dermatologists in India. The superiority of this combination is not supported by robust clinical trial data.

OBJECTIVE

We conducted this randomised, open-label, two arms, parallel assignment intervention trial between November 2022 and May 2023 to determine the superiority of topical 1% Luliconazole over bland emollient as adjuvant to systemic Itraconazole therapy in the management of dermatophytosis.

METHOD

In this study, 135 patients of either sex were randomised to two study cohorts. Major exclusions being concomitant medical illness, use of concomitant medication and substance abuse. Participants were randomly assigned to receive topical bland emollient, (Cohort I, n = 67) or topical luliconazole, (Cohort II, n = 68). Both cohorts received oral itraconazole 200 mg/day (100 mg BID) and levocetirizine 5 mg twice a day as a systemic regime. Clinical and mycological cure at the end of 6 weeks and clinical relapse among cure patients during 10-week follow-up were observed.

RESULTS

The cure rates for Cohorts I and II at 6 weeks were 50 (74.62%) and 56 (82.35%), (p = .46), respectively. During the 4-week follow-up period, clinical relapses were observed in 16 (32%) of the 50 patients in Cohort I and 12 (21.43%) of the 56 patients in Cohort II (p = .18). Luliconazole cohort shows a significantly higher medical cost (p < .05).

CONCLUSION

Our study shows a similar cure rate and relapse rate for patients receiving topical Luliconazole versus topical bland emollient as an adjuvant to the systemic itraconazole regime.

Treatment of onychomycosis in an era of antifungal resistance: Role for antifungal stewardship and topical antifungal agents

A growing body of literature has marked the emergence and spread of antifungal resistance among species of Trichophyton, the most prevalent cause of toenail and fingernail onychomycosis in the United States and Europe. We review published data on rates of oral antifungal resistance among Trichophyton species; causes of antifungal resistance and methods to counteract it; and in vitro data on the role of topical antifungals in the treatment of onychomycosis. Antifungal resistance among species of Trichophyton against terbinafine and itraconazole-the two most common oral treatments for onychomycosis and other superficial fungal infections caused by dermatophytes-has been detected around the globe. Fungal adaptations, patient characteristics (e.g., immunocompromised status; drug-drug interactions), and empirical diagnostic and treatment patterns may contribute to reduced antifungal efficacy and the development of antifungal resistance. Antifungal stewardship efforts aim to ensure proper antifungal use to limit antifungal resistance and improve clinical outcomes. In the treatment of onychomycosis, critical aspects of antifungal stewardship include proper identification of the fungal infection prior to initiation of treatment and improvements in physician and patient education. Topical ciclopirox, efinaconazole and tavaborole, delivered either alone or in combination with oral antifungals, have demonstrated efficacy in vitro against susceptible and/or resistant isolates of Trichophyton species, with low potential for development of antifungal resistance. Additional real-world long-term data are needed to monitor global rates of antifungal resistance and assess the efficacy of oral and topical antifungals, alone or in combination, in counteracting antifungal resistance in the treatment of onychomycosis.

Skin innate immune response against fungal infections and the potential role of trained immunity

Fungal skin infections are distributed worldwide and can be associated with economic and social traits. The immune response related to skin cells is complex and its understanding is essential to the comprehension of each cell's role and the discovery of treatment alternatives. The first studies of trained immunity (TI) described the ability of monocytes, macrophages and natural killer (NK) cells to develop a memory-like response. However, the duration of TI does not reflect the shorter lifespan of these cells. These conclusions supported later studies showing that TI can be observed in stem and haematopoietic cells and, more recently, also in non-immune skin cells such as fibroblasts, highlighting the importance of resident cells in response to skin disorders. Besides, the participation of less studied proinflammatory cytokines in the skin immune response, such as IL-36γ, shed light into a new possibility of inflammatory pathway blockade by drugs. In this review, we will discuss the skin immune response associated with fungal infections, the role of TI in skin and clinical evidence supporting opportunities and challenges of TI and other inflammatory responses in the pathogenesis of fungal skin infections.

Antifungal Activity of Nontoxic Nanocomposite Based on Silver and Reduced Graphene Oxide against Dermatophytes and Candida spp

Dermatomycoses are typical hair, skin, or nail infections caused mainly by dermatophytes and nondermatophytes: Trichophyton, Microsporum, Epidermophyton, and Candida. In addition to the esthetical impact, pain, and nail deformity, these mycoses can be a source of severe disease. The high cost of treatment, toxicity, and the emergence of resistant infectious agents justifies research into new drugs. This work evaluates the fungicidal activity of nanocomposites (NCs) based on reduced graphene oxide (rGO) loaded with silver (Ag) nanoparticles (rGO/Ag) against clinical isolates of dermatophytes and Candida species. This is an unprecedented study in which, for the first time, hybrid nanocompounds based on Ag/rGO were tested against Epidermophytom, Microsporum, and Trichophyton species (dermatophytes agents). In this paper, we synthesize rGO using different concentrations of Ag by hydrolysis of metal salt AgNO3 and follow the growth of nanocrystals on sheets of rGO provided by the NaBH4. The NCs were analyzed by X-ray diffraction analysis, and the NC morphology, silver distribution on the rGO surface, and crystalline information were investigated by transmission electron microscopy. Antifungal susceptibility assay was performed by the microdilution method based on modified Clinical and Laboratory Standards Institute (CLSI) protocol. Time-kill kinetics was conducted to monitor the effect of the composite to inhibit fungal cells or promote structural changes, avoiding germination. The toxicological evaluation of the NCs was born in an in vivo model based on Galleria mellonella (G. mellonella). Minimum inhibitory concentration (MIC) values of the rGO/Ag NCs ranged from 1.9 to 125 μg/mL. The best inhibitory activity was obtained for rGO/Ag12%, mainly against Candida spp. and Epidermophyton floccosum. In the presence of sorbitol, MIC values of rGO/Ag NCs were higher (ranging from 15.6 to 250 μg/mL), indicating the action mechanism on the cell wall. Both yeast and dermatophytes clinical isolates were inhibited at a minimum of 6 and 24 h, respectively, but after 2 and 12 h, they had initial antifungal interference. All hybrid formulations of rGO/Ag NCs were not toxic for G. mellonella. This study provides insights into an alternative therapeutic strategy for controlling dermatomycoses.

Development and Characterization of Econazole Topical Gel

The purpose of this work was to develop a novel topical formulation of econazole nitrate based on gel that can be easily scaled up in one pot for the potential treatment of fungal and yeast infections. Econazole nitrate, a topical antifungal, is used to treat tinea versicolor, tinea pedis, and tinea cruris. Compared to applying cream or ointment, topical gels offer numerous advantages, one of which is that the drug is released more quickly to the intended site of action. A viscous mixture of propylene glycol, Capmul® MCM C8, methyl and propyl paraben, and econazole nitrate were mixed together before being formulated into the optimized Carbopol® gel bases. The gel's color, appearance, and homogeneity were assessed visually. For every formulation, the drug content, pH, viscosity, spreadability, and gel strength were characterized. The cup plate diffusion method was used to evaluate the anti-fungal activity of the prepared formulations. To assess the behavior of the developed system, studies on in vitro release and mechanism were conducted. The manufactured formulations were transparent, pale yellow, and exhibited excellent homogeneity. The pH of each formulation was roughly 6.0, making them suitable for topical use. The concentration of Carbopol® 940 resulted in a significant increase in viscosity and gel strength but a significant decrease in spreadability. It was demonstrated that the prepared formulations inhibited the growth of Candida albicans and Aspergillus fumigatus. In contrast, the standard blank gel showed no signs of antifungal action. By increasing the concentration of Carbopol® 940, the in vitro release profile of econazole nitrate significantly decreased. Following the Korsmeyer-Peppas model fitting, all formulations exhibited n values greater than 0.5 and less than 1, indicating that diffusion and gel swelling control econazole nitrate release.

In Vitro Antifungal Activity of Selected Essential Oils against Drug-Resistant Clinical Aspergillus spp. Strains

BACKGROUND

Treatment options for aspergillosis include amphotericin B (AMB) and azole compounds, such as itraconazole (ITZ). However, serious side effects related to these antifungal agents are increasingly evident, and resistance continues to increase. Currently, a new trend in drug discovery to overcome this problem is represented by natural products from plants, or their extracts. Particularly, there is a great interest in essential oils (EOs) recognized for their antimicrobial role towards bacteria, fungi and viruses.

METHODS

In this study, we evaluated the antifungal activity of eleven commercial EOs-clove, eucalyptus, geranium, hybrid lavender, lavender, lemon, lemongrass, neroli, oregano, tea tree and red red thyme-in comparison with AMB and ITZ against Aspergillus flavus, A. fumigatus and A. niger clinical isolates. Antifungal activity was determined by broth microdilution method, agar diffusion technique, fungistatic and fungicidal activities and vapor contact assay.

RESULTS

Gas chromatography-mass spectrometry analysis displayed two groups of distinct biosynthetical origin: monoterpenes dominated the chemical composition of the most oils. Only two aromatic compounds (eugenol 78.91% and eugenyl acetate 11.64%) have been identified as major components in clove EO. Lemongrass EO exhibits the strongest antimicrobial activity with a minimum inhibitory concentration of 0.56 mg/mL and a minimum fungicidal concentration of 2.25-4.5 mg/mL against Aspergillus spp. strains. Clove and geranium EOs were fairly effective in inhibiting Aspergillus spp. growth.

CONCLUSIONS

These results demonstrate the antimicrobial potential of some EOs and support the research of new alternatives or complementary therapies based on EOs.

Combatting antifungal resistance: Paradigm shift in the diagnosis and management of onychomycosis and dermatomycosis

Antifungal resistance has become prevalent worldwide. Understanding the factors involved in spread of resistance allows the formulation of strategies to slow resistance development and likewise identify solutions for the treatment of highly recalcitrant fungal infections. To investigate the recent explosion of resistant strains, a literature review was performed focusing on four main areas: mechanisms of resistance to antifungal agents, diagnosis of superficial fungal infections, management, and stewardship. The use of traditional diagnostic tools such as culture, KOH analysis and minimum inhibitory concentration values on treatment were investigated and compared to the newer techniques such as molecular methods including whole genome sequencing, and polymerase chain reaction. The management of terbinafine-resistant strains is discussed. We have emphasized the need for antifungal stewardship including increasing surveillance for resistant infection.

Recalcitrant cutaneous fungal infections-A growing problem

The incidence and prevalence of recalcitrant cutaneous fungal infections is on the rise. Terbinafine-resistant Trichophyton has not only been widespread in India, but has also been reported in countries spread throughout the globe. Strains of yeasts such as Malassezia and Candida, which exist both as commensals and as pathogens to the human skin, have also been found to develop resistance to antifungals. Non-dermatophyte moulds which can colonize and infect damaged nails are especially difficult to treat, not only due to resistance, but also because of poor drug penetration of hard keratin. Psychosocial factors such as the indiscriminate broad-spectrum antifungal use in agriculture and in medicine, and poor adherence to hygienic measures to break the chain of infection contribute to the development of antifungal resistance. Such environments encourage fungi to develop various resistance mechanisms to withstand antifungal treatment. These include: (a) alteration of the drug target, (b) increasing efflux of drug/metabolites, (c) inactivation of drug, (d) bypass mechanisms or substitution of the pathway affected by the drug, (e) stress adaptation mechanisms and (f) biofilm formation. Understanding of such mechanisms and how they arise are crucial for development of new ways to prevent or overcome resistance. Novel antifungal treatments have recently been approved in the United States of America for treatment of vulvovaginal candidiasis. Ibrexafungerp (enfumafungin derivative) and oteseconazole (tetrazole) differ from their respective related drug classes of echinocandins and triazoles by having different structures, which lend these medicines advantage compared to traditional treatment by having a different binding site and more selectivity for fungi respectively. Other drugs designed to circumvent the known mechanisms of antifungal resistance are also at various phases of development. Concurrent measures at an institutional and individual level to address and limit inappropriate antifungal use to reduce development of antifungal resistance should be undertaken in a concerted effort to address this epidemic.

Relative impact of traditional vs. newer oral antifungals for dermatophyte toenail onychomycosis: a network meta-analysis study

BACKGROUND

There is a paucity of evidence regarding the relative therapeutic efficacy of treatments for onychomycosis.

OBJECTIVES

We determined the relative efficacy of monotherapies for dermatophyte toenail onychomycosis with Bayesian network meta-analyses (NMAs).

METHODS

We searched PubMed, Scopus, EMBASE (Ovid) and CINAHL to identify studies that investigated the efficacy of monotherapy with oral antifungals for dermatophyte toenail onychomycosis in adults. In this paper, 'regimen' corresponds to a given agent and its dosage. The relative effects and surface under the cumulative ranking curve (SUCRA) values of the various regimens were estimated; evidence quality was assessed at the study level and across networks.

RESULTS

Data from 21 studies were used. Our two efficacy-related endpoints were: (i) mycological and (ii) complete cure at 1 year; safety--related endpoints were: (i) 1-year count of any adverse event (AE), (ii) 1-year odds of discontinuation due to any AE, (iii) 1-year odds of discontinuation due to liver issues. Thirty-five regimens were identified; the newer agents among these included posaconazole and oteseconazole. We compared the efficacy of newer regimens with traditional ones like 'terbinafine 250 mg daily for 12 weeks' and 'itraconazole 200 mg daily for 12 weeks. We found that an agent's dosage was associated with its efficacy; for example, the 1-year odds of mycological cure with terbinafine 250 mg daily for 24 weeks (SUCRA = 92.4%) were significantly greater than those of terbinafine 250 mg daily for 12 weeks (SUCRA = 66.3%) (odds ratio 2.62, 95% credible interval 1.57-4.54). We also found that booster regimens can increase efficacy. Our results showed that some triazoles could be more effective than terbinafine.

CONCLUSIONS

This is the first NMA study of monotherapeutic antifungals - and their various dosages - for dermatophyte toenail onychomycosis. Our findings could provide guidance for the selection of the most appropriate antifungal agent, especially amid the growing concerns about terbinafine resistance.

Isolation of Terbinafine-Resistant Trichophyton rubrum from Onychomycosis Patients Who Failed Treatment at an Academic Center in New York, United States

Onychomycosis is a common nail infection. Terbinafine-resistant dermatophyte infections pose an emerging global public health concern, but few cases have been described in the United States. We retrospectively reviewed and characterized clinical, histopathological, and mycological features of patients with mycologically confirmed onychomycosis who failed oral terbinafine treatment for onychomycosis at a U.S. academic nail referral center and ascertained for terbinafine-resistant isolates. During 1 June 2022-31 January 2023 at Weill Cornell Medicine in New York City, USA, 96 patients with mycologically confirmed onychomycosis were treated with oral terbinafine. Among 64 patients with adequate follow-up, 36 had clinical or complete cure. Of 28 patients who failed treatment, 17 underwent terbinafine resistance testing. Trichophyton rubrum with terbinafine resistance-conferring mutations was isolated from two patients. Overall, terbinafine failures for onychomycosis were relatively common, with some cases associated with terbinafine-resistant T. rubrum infections. These findings underscore the need for a clinical awareness of this emerging problem and public health efforts to monitor and prevent spread. We highlight the importance of diagnostic testing and species identification for onychomycosis patients and the increasingly important role of fungal identification and susceptibility testing to guide therapy.

Strategies to improve the diagnosis and clinical treatment of dermatophyte infections

INTRODUCTION

Significant problems are associated with the diagnosis and treatment of dermatophyte infections, which constitute the most common fungal infections of the skin. Although this is a common problem in the community, there are no adequate guidelines for the management of all forms of dermatophyte infections. Even if dermatophytes are correctly diagnosed, they sometimes exhibit poor susceptibility to several antifungal compounds. Therefore, long-term treatment may be needed, especially in immunosuppressed patients, for whom antifungal pharmacotherapy may be inconvenient owing to allergies and undesirable drug interaction-related effects.

AREAS COVERED

In this review article, problems related to the diagnosis and treatment of dermatophyte infections have been discussed, and suggestions to resolve these problems have been presented.

EXPERT OPINION

Pretreatment microscopic or mycological examinations should be performed for dermatophyte infections. In treatment-refractory cases, antifungal-resistant strains should be determined using antifungal susceptibility testing or via molecular methods. Natural herbal, laser, and photodynamic treatments can be used as alternative treatments in patients who cannot tolerate topical and systemic antifungal treatments.

Distribution and antifungal susceptibility pattern of Candida species from mainland China: A systematic analysis

Antifungal resistance to Candida pathogens increases morbidity and mortality of immunosuppressive patients, an emerging crisis worldwide. Understanding the Candida prevalence and antifungal susceptibility pattern is necessary to control and treat candidiasis. We aimed to systematically analyse the susceptibility profiles of Candida species published in the last ten years (December 2011 to December 2021) from mainland China. The studies were collected from PubMed, Google Scholar, and Science Direct search engines. Out of 89 included studies, a total of 44,716 Candida isolates were collected, mainly comprising C. albicans (49.36%), C. tropicalis (21.89%), C. parapsilosis (13.92%), and C. glabrata (11.37%). The lowest susceptibility was detected for azole group; fluconazole susceptibilities against C. parapsilosis, C. albicans, C. glabrata, C. tropicalis, C. guilliermondii, C. pelliculosa, and C. auris were 93.25%, 91.6%, 79.4%, 77.95%, 76%, 50%, and 0% respectively. Amphotericin B and anidulafungin were the most susceptible drugs for all Candida species. Resistance to azole was mainly linked with mutations in ERG11, ERG3, ERG4, MRR1-2, MSH-2, and PDR-1 genes. Mutation in FKS-1 and FKS-2 in C. auris and C. glabrata causing resistance to echinocandins was stated in two studies. Gaps in the studies' characteristics were detected, such as 79.77%, 47.19 %, 26.97%, 7.86%, and 4.49% studies did not mention the mortality rates, age, gender, breakpoint reference guidelines, and fungal identification method, respectively. The current study demonstrates the overall antifungal susceptibility pattern of Candida species, gaps in surveillance studies and risk-reduction strategies that could be supportive in candidiasis therapy and for the researchers in their future studies.

A Dual-Plasmid-Based CRISPR/Cas9-Mediated Strategy Enables Targeted Editing of pH Regulatory Gene pacC in a Clinical Isolate of Trichophyton rubrum

Trichophyton rubrum is the most prevalent causative agent responsible for 80-90% of all known superficial fungal infections in humans, worldwide. Limited available methods for genetic manipulations have been one of the major bottlenecks in understanding relevant molecular mechanisms of disease pathogenesis in T. rubrum. Here, a dual-plasmid-based CRISPR/Cas9 strategy to edit pH regulatory transcription factor, pacC, of a clinical isolate of T. rubrum by non-homologous end joining (NHEJ) repair is presented. A cas9-eGFP fusion that aids pre-screening of primary transformants through detection of GFP fluorescence is expressed from one plasmid while target-specific sgRNA from the other brings about mutagenesis of pacC with an overall efficiency of 33.8-37.3%. The mutants had reduced transcript levels of pacC at both acidic and alkaline pH with several morphological abnormalities. We believe this dual-plasmid-based CRISPR/Cas9 strategy will aid functional genomics studies, especially in non-lab-adapted clinical strains of T. rubrum.

Disinfection trials with terbinafine-susceptible and -resistant dermatophytes

BACKGROUND

Treatment of tinea pedis and onychomycosis is complicated by high rates of reinfection and the emergence of terbinafine-resistant strains of Trichophyton spp. Effective disinfection of contaminated socks is an important measure. Appropriate washing reduces the risk of reinfection and is paramount in treating tinea pedis and onychomycosis.

OBJECTIVES

The aim of this study is to describe the effect of commonplace disinfection methods using socks pieces inoculated with terbinafine-resistant or terbinafine-susceptible isolates of Trichophyton spp.

METHODS

Sock pieces were inoculated with seven terbinafine-resistant isolates of Trichophyton spp. with known mutations in the SQLE-gene (T. rubrum (n=3), T. interdigitale (n=1), and T. indotineae (n=3)) and six terbinafine-susceptible isolates of Trichophyton spp. (T. rubrum (n=3) and T. interdigitale (n=3)). Methods of disinfection included soaking in a quaternary ammonium (QAC) detergent (0.5, 2, and 24 hours), freezing at -20°C (0.5, 12, and 24 hours), domestic washing (40°C with detergent), and steam washing (40°C with detergent). Sock pieces were cultured for 4 weeks following disinfection. The primary end point was no growth at the end of week 4.

RESULTS

Soaking in QAC-detergent for 24 hours procured at disinfectant rate of 100% (13/13), whilst soaking in 0.5 and 2 hours had a disinfectant rate of 46% (6/13) and 85% (11/13), respectively. Domestic washing (40°C with detergent) produced a disinfectant rate of 7.7% (1/13). Freezing at -20°C (0.5, 12, and 24 hours) and steam washing (40°C with detergent) had no disinfectant properties.

CONCLUSIONS

Soaking socks contaminated with dermatophytes in a QAC-detergent for 24 hours disinfects socks.