Fungal Infections From Human and Animal Contact

Current Performance of MALDI-TOF Mass Spectrometry Databases for the Identification of Dermatophyte Species

The identification of filamentous fungi by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) represents a challenge due to their complex taxonomy and the lack of comprehensive databases. The aim of this study was to evaluate the current status of available MALDI-TOF MS databases for the identification of dermatophytes, including commercial, in-house, and web-based databases. We collected 289 dermatophyte strains from different centers and analyzed them using four databases and a combination of them. The combination of commercial and in-house databases was shown to improve the identification rate and accuracy at the species level. For Trichophyton rubrum, the concordance among all databases was above 90.0%. For the T. mentagrophytes group, correct identification at the species level ranged from 30.0 to 78.9%, depending on the database, and showed very low agreement among them. The addition of the novel species T. japonicum to our in-house database resulted in the successful identification of this species. On the other hand, T. interdigitale and T. tonsurans were the species most frequently misidentified by MALDI-TOF MS. Through deep spectra analysis of both species, up to 29 protein peaks were found to be suitable for their differentiation, demonstrating the potential of peak analysis in differentiating closely related species. In conclusion, improvements of the databases with new strains resulted in increased identification accuracy at the species level. This, combined with peak analysis, could improve the overall identification of dermatophytes by MALDI-TOF MS in clinical laboratories.

Molecular epidemiology of dermatophytosis in Golestan, Iran: A cross-sectional study

Keratinophilic fungi, or dermatophytes, are recognized as the predominant fungal agents responsible for superficial skin diseases globally. The identification of species of dermatophytes is crucial for both therapeutic and epidemiological considerations. The primary objective of the present study was to investigate the epidemiology of dermatophytosis among patients who sought medical attention at the medical mycology laboratory in Golestan province. This study aims to provide a comprehensive assessment and analysis of fungal infections occurring in many anatomical regions of the human body and the several diagnostic procedures employed to confirm such infections. In this investigation, 255/550 clinical specimens were obtained from patients thought to have dermatophytosis. All samples underwent direct microscopy and culture examinations. DNA extraction from a fungal colony was conducted using the phenol-chloroform method. Then, the ITS1-5.8s-ITS2 region of ribosomal DNA (rDNA) was amplified by the universal fungal primers ITS1 and ITS4 and digested with enzymes Mval. In the current study, 255 patients (46.3 %) were positive for dermatophytosis. Of these, 38.4 % were male and 61.6 % female. The most common dermatophytes isolated were Trichophyton mentagrophytes/interdigitale (86.7 %) and Trichophyton rubrum (5.1 %), respectivly. The frequency of other species were Trichophyton tonsurans (3.1 %), Microsporum canis (2.7 %), Trichophyton benhamiae (0.8 %), Trichophyton violaceum (0.8 %), Trichophyton quinckeanum (0.4 %), and Microsporum ferrugineum (0.4 %). The findings indicated that Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) is an expeditious and dependable technique for diagnosing dermatophytes. In combination with morphological analysis, PCR-RFLP is recommended as a valuable approach for identifying dermatophytes in diagnostic contexts, particularly within clinical and epidemiological settings.

Identification of Challenging Dermatophyte Species Using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a widely adopted technique for bacterial and yeast identification in clinical laboratories but is less frequently applied to filamentous fungi due to inconsistent performance, limitations of commercial libraries, and variability of preparation methods. This study aimed to validate the efficiency of MALDI-TOF MS-based dermatophyte identification using the Bruker Biotyper system. Focusing on species from the Trichophyton, Nannizzia, Microsporum, and Epidermophyton genera, an in-house reference library was established and evaluated with clinical isolates. The expanded library, which combined the in-house and Bruker libraries, achieved significantly higher accuracy than the Bruker library alone, correctly identifying 90.7% (107/118) of isolates at the species level compared to 16.1% (19/118) by the Bruker library. This study presents an efficient, standardized MALDI-TOF MS protocol for routine dermatophyte identification and provides a review of the current status and influencing factors in MALDI-TOF MS-based dermatophyte identification strategies.

Mycological Profile and Associated Factors Among Patients with Dermatophytosis in Astana, Kazakhstan

Dermatophytosis, also known as Tinea infection, remains a significant interdisciplinary concern worldwide. This dermatophyte infection may be more serious in individuals with underlying somatic diseases, immunodeficiencies, endocrine disorders, or chronic illnesses. This study analyzed 313 patients with suspected dermatophytosis. Data were gathered through questionnaires and medical records were reviewed. Biological samples were cultured on Sabouraud dextrose agar, and PCR was employed to assess the genetic diversity of strains. Statistical analysis was conducted using SPSS version 26. The overall prevalence of dermatophytosis in the cohort was 30.4%. Among the cultured isolates, 73.7% were identified as Microsporum canis, while 26.3% were identified as Trichophyton species, including T. mentagrophytes, T. tonsurans, and T. verrucosum. Several factors were significantly associated with an increased risk of dermatophytosis, including the following: male gender (AOR = 1.97), age 1-10 years (AOR = 3.80), living in rural areas (AOR = 2.30), visiting public bathhouses (AOR = 2.32), visiting massage parlors (AOR = 1.39), contact with cats (AOR = 2.32), family history of dermatophytosis (AOR = 3.04), and sexual contact with an infected or unknown partner (AOR = 3.08). Dermatophytosis was identified in approximately one third of the patients by culture (30.4%), with the risk heightened in individuals under 10 years old (43.6%), those living in rural areas (33.3%), and those with a family history of dermatophytosis (35.7%) or close contact with cats (39.4%). The findings underscore the need for strengthened preventive measures and targeted diagnostics, particularly among high-risk groups.

Comprehensive Review of Tinea Capitis in Adults: Epidemiology, Risk Factors, Clinical Presentations, and Management

Tinea capitis is a fungal infection of the scalp and hair caused by dermatophyte molds, that most often affects children and may also affect adults. Previous estimates suggest that between 3% and 11% of all tinea capitis cases worldwide occur in adults, although updated epidemiological studies are needed to reassess the prevalence of tinea capitis in adult populations specifically. Postmenopausal adult women are most often affected by tinea capitis, with African American or Black women particularly at risk. Adults who experience crowded living conditions, who live in close proximity to animals, who are immunosuppressed, and/or who live in households with affected children are at greatest risk of infection. Tinea capitis can be non-inflammatory or inflammatory in nature, and the subtype affects the extent and severity of clinical symptoms. Fungal culture and potassium hydroxide preparations are the most commonly used diagnostic tools. Trichoscopy, defined as dermoscopic imaging of the scalp and hair, is a useful adjunct to the physical examination. The mainstay of therapy is oral antifungal therapy, and topical therapy alone is not recommended. Since tinea capitis infection is uncommon in adults, there are no widely accepted treatment guidelines. Rather, the same medications used for tinea capitis infection among children are recommended for adults at varying doses, including griseofulvin, and terbinafine, and, less commonly, itraconazole and fluconazole. The prognosis for tinea capitis in adults is typically excellent when prompt and adequate treatment is administered; however, delayed diagnosis or inadequate treatment can result in scarring alopecia. Over the past decade, dermatophyte infections resistant to treatment with topical and oral antifungal agents have emerged. While tinea capitis infections resistant to antifungal therapy have been rarely reported to date, antifungal resistance is rising among superficial fungal infections in general, and antifungal stewardship is necessary to ensure that resistance to treatment does not develop among dermatophytes that cause tinea capitis.

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.

Over-the-Counter Medicine-Seeking Behavior in Patients With Dermatophyte Infections Across Various Socioeconomic Strata: A Cross-Sectional Study

BACKGROUND AND OBJECTIVE

In dermatology outpatient departments in India, dermatophytosis is the most commonly encountered dermatosis. The objective was to collect data regarding the prevalence of over-the-counter (OTC) medication, knowledge of the illness, and hygiene habits among people with dermatophyte infections across various socioeconomic classes.

METHODS

At a tertiary care facility in central India, a cross-sectional study was carried out over six months. Data about socioeconomic class, hygiene routines, prior history of any type of treatment, understanding of the condition, and family history of similar illnesses were noted. A total of 551 patients were included in the study. The correlation was evaluated using Spearman's correlation coefficient (rho).

RESULTS

Socioeconomic class had little impact on seeking dermatologist advice. Steroids were prescribed to approximately 81.8% of all patients. There was a positive correlation (rho = 0.237) between the use of steroids and the severity of the condition. Around 34% of patients took prescription medications, as recommended by a pharmacist. The use of steroids positively correlated (rho = 0.426, p<0.001) with prescriptions by pharmacists. Over-the-counter drug availability and individuals believing pharmacists were qualified to identify and treat illnesses were significant contributing causes.

CONCLUSIONS

People from all socioeconomic strata need to be made more aware of the risks associated with the inappropriate use of medications and skin problems in general. Strict regulations to control prescription drug sales and deter practitioners of alternative medicine from prescribing allopathic medications may be beneficial.

A Systematic Review of Curtisia dentata Endemic to South Africa: Phytochemistry, Pharmacology, and Toxicology

The use of traditional medicine in treating a variety of both human and animal infections is ancient and still relevant. This is due to the resistance exhibited by most pathogenic microbial stains to currently-used antibiotics. The current work reports the phytochemistry, ethno-medicinal uses, toxicology, and most important pharmacological activities that validate the use of the plant species in African traditional medicine. Curtisia dendata is used in the treatment of many human and animal infections, including diarrhea, skin and related conditions, sexually transmitted infections, cancer, and a variety of ethno-veterinary infections. Pharmacologically, the plant species exhibited potent antimicrobial activity against a variety of pathogens. Further, both extracts and compounds isolated from the plant species exhibited potent antioxidant, anticancer, anti-parasitic, anti-inflammatory, and other important biological activities. Phytochemically, the plant species possess a variety of compounds, particularly triterpenes, that may well explain the various pharmacological activities of the plant species. The toxicological parameters, antimicrobial activities against microorganisms related to sexually transmitted infections, anti-diabetic effects, and inflammatory properties of the plant species are not well studied and still need to be explored. The biological activities observed validate the use of the plant species in African traditional medicine, particularly in the treatment of pulmonary infections associated with Mycobacterium species, and may well be due to the presence of triterpenes prevalent in the leaves.

In vitro antifungal activity of heterocyclic organoboron compounds against Trichophyton mentagrophytes and Microsporum canis obtained from clinical isolates

The aim of this study was to investigate the in vitro activity of thirty-eight heterocyclic organoboron compounds (1a-o, 2a-j, 3a-m) against clinically isolated dermatophytes Trichophyton mentagrophytes and Microsporum canis. Minimum inhibitory concentrations (MICs) of compounds (1a-o, 2a-j, 3a-m) were determined according to published protocol Clinical and Laboratory Standards Institute (CLSI) M38-A2 broth microdilution method. The minimum fungicidal concentrations (MFCs) for both T. mentagrophytes and M. canis were found by subculturing each fungal suspension on potato dextrose agar. According to the results, heterocyclic organoboron compounds (1a-o, 2a-j, 3a-m) were found to be more effective against dermatophyte M. canis (MIC = 3.12-25 µg/ml) than T. mentagrophytes (MIC = 12.5-100 µg/ml). Our findings showed that 7-membered heterocyclic organoboron compounds (3a-m) (MIC = 12.5-50 µg/ml) have stronger in vitro antifungal activity against T. mentagrophytes than 5-membered heterocyclic organoboron compounds (1a-o, 2a-j) (MIC = 25-100 µg/ml). The MFC values for all compounds ranged from 6.25 to 200 µg/ml. The limited number of systemic antifungal agents used in the treatment of dermatophyte infections and the presence of side effects have led to the search for new treatment resources in recent years. Therefore, investigation of the effect of heterocyclic organoboron compounds against dermatophytes will be promising for the discovery of new antifungal compounds that have gained great importance today.

Effect of Household Laundering, Heat Drying, and Freezing on the Survival of Dermatophyte Conidia

Dermatomycoses are one of the most common dermatological infectious diseases. Dermatophytoses, such as tinea pedis (athlete’s foot) in adults and tinea capitis in children, are the most prevalent fungal diseases caused by dermatophytes. The transmission of anthropophilic dermatophytoses occurs almost exclusively through indirect contact with patient-contaminated belongings or environments and, subsequently, facilitates the spread of the infection to others. Hygienic measures were demonstrated to have an important role in removing or reducing the fungal burden. Herein, we evaluated the effectiveness of physical-based methods of laundering, heat drying, and freezing in the elimination of Trichophyton tonsurans, T. rubrum, and T. interdigitale conidia in diverse temperatures and time spectra. Based on our findings, laundering at 60 °C was effective for removing the dermatophyte conidia from contaminated linens. On the contrary, heat drying using domestic or laundromat machines; freezing at −20 °C for 24 h, 48 h, or one week; and direct heat exposure at 60 °C for 10, 30, or 90 min were unable to kill the dermatophytes. These results can be helpful for clinicians, staff of children’s communities, and hygiene practitioners for implementing control management strategies against dermatophytoses caused by mentioned dermatophyte species.

Transmission of Onychomycosis and Dermatophytosis between Household Members: A Scoping Review

Onychomycosis is a common fungal infection of the nail, caused by dermatophytes, non-dermatophytes, and yeasts. Predisposing factors include older age, trauma, diabetes, immunosuppression, and previous history of nail psoriasis or tinea pedis. Though many biological risk factors have been well characterized, the role of the environment has been less clear. Studies have found evidence of transmission in 44% to 47% of households with at least one affected individual, but the underlying mechanisms and risk factors for transmission of onychomycosis between household members are incompletely understood. A scoping literature review was performed to characterize and summarize environmental risk factors involved in the transmission of onychomycosis within households. A total of 90 papers met the inclusion criteria, and extracted data was analyzed in an iterative manner. Shared household surfaces may harbor dermatophytes and provide sources for infection. Shared household equipment, including footwear, bedding, and nail tools, may transmit dermatophytes. The persistence of dermatophytes on household cleaning supplies, linen, and pets may serve as lasting sources of infection. Based on these findings, we provide recommendations that aim to interrupt household transmission of onychomycosis. Further investigation of the specific mechanisms behind household spread is needed to break the cycle of transmission, reducing the physical and social impacts of onychomycosis.

Isolation Of Dermatophytes From Infected Stray Cats In Selangor

Background: Dermatophytosis is the most prevalent fungal infection found in cats and one of the most serious infectious skin diseases that affect this species. Dermatophytosis can be endemic in cats, particularly in poor environments, and it is difficult to eradicate in such cases. Purpose: The aim of this research was to determine the macroscopic and microscopic identification of various types of dermatophytes present in stray cats. Methods: The research was designed as a laboratory-based study. The sample was determined through physical examination of stray cats infected with fungi and was selected based on the infection site (nail, hair, and skin) of infected cats. A total of 125 samples were collected from infected stray cats through skin scraping, haircutting, and nail clipping. The collected samples were then cultured in Sabouraud Dextrose Agar (SDA) medium and incubated for two weeks at 26°C. Following incubation, fungi were stained using Lacto-phenol Cotton Blue (LPCB) for microscopic identification. Results: The identification showed that Trichophyton spp. is the most common isolated fungal species on the hair, nails, and skin of stray cats. This is followed by Aspergillus spp. and Microsporum spp. The least common dermatophytes include Curvularia spp., Absidia spp., Epidermophyton spp., Neosytallidium spp., Alternaria spp., Scopulariopsis spp., Mucor spp., and Penicillium spp. Conclusion: The research focussed exclusively on stray cats with clinical evidence of mycotic lesions and confirmed the role of stray cats in transmitting dermatophytosis through their hair, nails, and skin. The prevalence of dermatophytes on stray cats was identified in the Selangor region.

Epidemiology of Dermatophytes Isolated from Clinical Samples in a Hospital in Eastern Saudi Arabia: A 20-Year Survey

BACKGROUND

Dermatophytes are group of fungi that cause superficial infections via enzymes that degrade keratin in human skin. Several factors, including climate, gender, age, lifestyle, human migration, cultural habits, and socioeconomic status influence the prevalence of dermatophyte infections. We analyzed the prevalence of dermatophyte isolates in a hospital in Eastern Saudi Arabia from 2000 to 2019.

METHODS

The data on fungal cultures were obtained from the Laboratory Information System of the Mycology Laboratories at Johns Hopkins Aramco Healthcare, and were used for the analysis. Fungal isolates were examined microscopically for the presence of specialized hyphal structures and conidia. The Vitek^® MS microbial identification system (biomerieux) was used if the culture type was not identified microscopically.

RESULTS

Among the 10,021 samples analyzed, 3040 (30.33%) were positive for fungi and only 398 (3.97%) were dermatophytes. Microsporum species was the most common dermatophyte accounting for 50.5% (n = 201) followed by trichophyton with 36.9% (n = 147). The most common positive samples were scrapping (251, 63%) and hair (68, 17%). Culture positivity relative to the age groups revealed a cluster of positive dermatophyte species in children < 10 years of age with 215 (54%) of all cases and among 10-19 years of age with 60 (15) of the cases (p < 0.001). Microsporum species were the prevalent dermatophytes in patients  < 10 years of age, while Epidermophyton species were the most frequent dermatophyte species in age groups 10-19, 20-29, and 30-39 years. However, Trichophyton species were the most frequent dermatophyte species in individuals 70-79 years. The percentage of Microsporum and Trichophyton species decreased significantly over time (p < 0.001). In addition, there was a significant seasonal variation in relation to Trichophyton species. A comparison between the most frequent species showed that there was no difference in relation to gender, but there was a difference in relation to the specimen type and age group.

CONCLUSION

Dermatophytosis was common among children and adolescent with the most common samples were scrapping and hair. There was a significant reduction in Microsporum and Trichophyton species over time.

Cold atmospheric pressure plasma (CAPP) as a new alternative treatment method for onychomycosis caused by Trichophyton verrucosum: in vitro studies

PURPOSE

Anthropophilic dermatophytes as etiological factors of onychomycoses are more common than zoophilic fungi. In the case of the latter, reverse zoonoses are possible, which poses a threat to the persistence of dermatophytes in the environment. Nevertheless, without treatment, both types of tinea unguium may lead to complete nail plate destruction and secondary mixed infections with fungi and bacteria. One of the zoophilic dermatophytes that cause onychomycosis is Trichophyton verrucosum, whose prevalence has been increasing in recent years. Such infections are usually treated with allylamines and/or azoles, but such a conventional treatment of infections caused by T. verrucosum often fails or is discontinued by patients.

METHODS

Herein, we reveal the results of our in vitro studies related to direct application of cold atmospheric pressure plasma (CAPP) on Trichophyton verrucosum growth, germination and adherence to nail as a new alternative treatment method of such types of dermatomycoses.

RESULTS

Our in vitro studies showed that, while exposure to CAPP for 10 min delays germination of conidia and clearly impairs the fitness of the fungal structures, 15 min is enough to kill all fungal elements exposed to plasma. Moreover, the SEM images revealed that T. verrucosum cultures exposed to CAPP for 10 and 15 min were not able to invade the nail fragments.

CONCLUSION

The results revealed that single exposure to CAPP was able to inhibit T. verrucosum growth and infection capacity. Hence, cold atmospheric pressure plasma should be considered as a promising alternative treatment of onychomycoses.

Good Visual Outcome in Post Traumatic Exogenous Endophthalmitis Caused by Trichophyton Species

Trichophyton species is a dermatophytic fungus commonly found in the skin, nails, hair, and other organic matters such as palm trees and soil. We report a rare case of a 23-year-old man who had a penetrating injury to the eye from the leaves of a palm tree and subsequently developed exogenous endophthalmitis. Culture from the vitreous tap revealed Trichophyton sp as the causative organism. Early vitrectomy and adequate intravitreal injection of amphotericin B resulted in good visual outcomes in an otherwise blinding condition. This is the first reported case of exogenous endophthalmitis secondary to Trichophyton species. Early diagnosis and prompt treatment may help improve visual outcomes.

A Review on Antifungal Efficiency of Plant Extracts Entrenched Polysaccharide-Based Nanohydrogels

Human skin acts as a physical barrier; however, sometimes the skin gets infected by fungi, which becomes more severe if the infection occurs on the third layer of the skin. Azole derivative-based antifungal creams, liquids, or sprays are available to treat fungal infections; however, these formulations show various side effects on the application site. Over the past few years, herbal extracts and various essential oils have shown effective antifungal activity. Additionally, autoxidation and epimerization are significant problems with the direct use of herbal extracts. Hence, to overcome these obstacles, polysaccharide-based nanohydrogels embedded with natural plant extracts and oils have become the primary choice of pharmaceutical scientists. These gels protect plant-based bioactive compounds and are effective delivery agents because they release multiple bioactive compounds in the targeted area. Nanohydrogels can be applied to infected areas, and due to their contagious nature and penetration power, they get directly absorbed through the skin, quickly reaching the skin's third layer and effectively reducing the fungal infection. In this review, we explain various skin fungal infections, possible treatments, and the effective utilization of plant extract and oil-embedded polysaccharide-based nanohydrogels.

Isolation of Dermatophytes from Infected Stray Dogs in Selangor, Malaysia

Background: Dermatophytosis is one of the most common skin diseases that affects cats and dogs. Geographic factors play an important role in determining prevalence, showing high rates of prevalence in warm and humid environments. Purpose: The aim of this study was to determine the macroscopic and microscopic identification of different types of dermatophytes present on stray dogs. Methods: The design of this study was laboratory-based research. Each sample was collected from an infection site (nail, hair, or skin) that was identified by conducting a physical examination of a stray dog that was infected with fungi. The skin scraping, nail clipping, and fur cutting samples were collected from infected dogs and then cultured on Sabouraud Dextrose Agar (SDA). The cultures were incubated at 26°C for five weeks. The isolates of fungi were then examined macroscopically and microscopically. The Lactophenol Cotton Blue (LPCB) staining technique was used for fungi morphology identification. Results: Overall, the most common type of dermatophytes that affected the dogs were Trichophyton spp. (64.70%), Aspergillus spp. (10.10%), Microsporum spp. (7.20%), and Curvularia spp. (5.60%). Conclusion: This study revealed the most common dermatophyte infections found on stray dogs in Selangor, Malaysia. This study can assist investigators in understanding the prevalence of the dermatophyte burden in stray dogs and help prevent further complication, such as the spread of illness, especially zoonotic infection.

Sterol 14α-Demethylase Ligand-Binding Pocket-Mediated Acquired and Intrinsic Azole Resistance in Fungal Pathogens

The fungal cytochrome P450 enzyme sterol 14α-demethylase (SDM) is a key enzyme in the ergosterol biosynthesis pathway. The binding of azoles to the active site of SDM results in a depletion of ergosterol, the accumulation of toxic intermediates and growth inhibition. The prevalence of azole-resistant strains and fungi is increasing in both agriculture and medicine. This can lead to major yield loss during food production and therapeutic failure in medical settings. Diverse mechanisms are responsible for azole resistance. They include amino acid (AA) substitutions in SDM and overexpression of SDM and/or efflux pumps. This review considers AA affecting the ligand-binding pocket of SDMs with a primary focus on substitutions that affect interactions between the active site and the substrate and inhibitory ligands. Some of these interactions are particularly important for the binding of short-tailed azoles (e.g., voriconazole). We highlight the occurrence throughout the fungal kingdom of some key AA substitutions. Elucidation of the role of these AAs and their substitutions may assist drug design in overcoming some common forms of innate and acquired azole resistance.

Detection and identification of dermatophytes based on currently available methods - a comparative study

AIMS

Accurate identification of dermatophytes is essential for implementing appropriate antifungal treatment and epidemiological analysis. However, the limitations of conventional diagnostics are a frequently discussed topic, and new diagnostic techniques are constantly expanding. In this study, we assess the suitability of conventional diagnostic techniques in comparison to the real-time PCR assay and MALDI-TOF MS in detection and identification of dermatophytes.

METHODS AND RESULTS

Strains included in this study were obtained from human and animals with symptomatic, and asymptomatic infection. A direct examination revealed that 31·7 and 60·9% of samples from symptomatic patients, and 25·7 and 60% from asymptomatic animals were positive, as shown by light and fluorescence microscopy respectively. In turn, dermatophytes were isolated from 90·2 and 71·4% of these samples. The pan-dermatophyte primers in real-time PCR assay facilitated detection in 85·3 and 82·9% of the symptomatic and asymptomatic dermatophytoses respectively. Additionally, species-specific PCR assays were positive in 70·7 and 37·1% of these samples. The MALDI-TOF MS analysis yielded positive results consistent with conventional techniques in 97·2 and 72% of symptomatic and asymptomatic infections respectively.

CONCLUSIONS

Our study revealed that there is no universal diagnostic method that would be ideal in each of the cases considered. Nonetheless, conventional techniques are still the most effective and reliable tools for mycological diagnostics.

SIGNIFICANCE AND IMPACT OF THE STUDY

Dermatologists and veterinarians have difficulties in making a diagnosis of dermatophytoses based only on observed symptoms of fungal infections, as they mimic symptoms of other dermatoses. In this context, a comparative analysis of the results of diagnostics performed using conventional methods and new technologies are crucial for implementing these pioneer methods into routine laboratory practice.

The effect of cytoplasmic crude extracts of Trichophyton verrucosum on cell mediated immunity

OBJECTIVE

Trichophyton verrucosum is a slow growing dermatophyte responsible for a number of skin diseases such as ringworm, and is characterized by patches of hair loss and thick crusts on the host skin in domestic animals. In this study, we examined the immunomodulatory effects of crude extract of Trichophyton verrucosum (TV)cytoplasm in a mouse model.

METHODS

The TV variate was cultured on Sabouraud dextrose agar and the mycelium was grinded by mechanical force. The purified protein was obtained from crude extract of the fungus, and protein concentration was measured by BradFord assay. Six to eight week-female BALB/c mice were divided into three groups: test group, receiving cytoplasmic crude extract plus defibrinated sheep blood; control group, receiving defibrinated sheep blood; and normal group, receiving normal saline. Injections were performed on days 0, 3, 5, 7 and 9 and the mice were sacrificed four days after the last injection. T lymphocyte metabolic activity was examined by methyl thiazol tetrazolium (MTT) assay, and also interleukin-4 (IL-4) and interferon-γ (IFNγ) levels were evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

MTT assay showed that the TV extract stimulated lymphocyte metabolic activity. ELISA results showed that despite increase in the level of IFNγ, no changes were observed in IL-4 level.

CONCLUSIONS

Results indicated that crude extract of TV cytoplasm may probably act as an immune modulator, which affects Th₁ responses. The TV crude extract may be an appropriate agent to induce cellular immunity for combating dermatophytosis infection in animals; and therefore, TV extract may have some potential applications in vaccine/adjuvant technology.

Review on pulp and paper activated sludge pretreatment, inhibitory effects and detoxification strategies for biovalorization

Biovalorization of pulp and paper activated sludge to value-added products could be an effective alternative to traditional sludge management methods, which tend to pose serious environmental issues. Since pulp and paper activated sludge consists of microbial biomass, cellulose, hemicellulose and lignin and thus, could be subjected to different hydrolysis methods to solubilize sludge solids and release simple sugars to form value-added products by the microbial fermentation process. Hence, different sludge hydrolysis methods have been summarized in this review paper. However, hydrolysis of lignocellulosic materials generates variety of toxic compounds during hydrolysis and causes detrimental effects. Therefore, different toxic compounds and their impact on microorganisms, cellulolytic enzymes and fermentation process have been discussed in detail and recent strategies to counteract the problems of inhibitors have also been briefly explained.

Major challenges and perspectives in the diagnostics and treatment of dermatophyte infections

Dermatophytes are the aetiological factors of a majority of superficial fungal infections. What distinguishes them from other pathogenic filamentous fungi is their unique ability to degrade keratin. The remarkable ability of this group of fungi to survive in different ecosystems results from their morphological and ecological diversity as well as high adaptability to changing environmental conditions. Paradoxically, despite the progress in medicine, the prevalence of dermatophyte infections is increasing from year to year. At the beginning of the third millennium, practical diagnostic and therapeutic options are still very limited. This review focuses on understanding the major problems in this aspect of dermatophyte infections and indicates future strategies and perspectives for novel approaches to identification and drugs for elimination of dermatophytes. Particular importance is placed on development of a strategy for a diagnostic pathway and implementation of rapid and reliable diagnostics methods designed by international teams. Furthermore, among compounds that currently arouse great interest, representatives of terpenoids, alkaloids, saponins, flavonoids and essential oils deserve attention. Many of these compounds are undergoing clinical trials as potential antifungal agents, and future research should focus on attempts at determination of the applicability of tested substances. Finally, the advantages and disadvantages in implementation of new diagnostic paths and medicinal substances for routine use are indicated.

Microbiology of hospital wastewater

The study of hospital wastewater (HWW) microbiology is important to understand the pollution load, growth of particular pathogenic microbes, shift and drift in microbial community, development and spread of antibiotic resistance in microbes, and subsequent change in treatment efficiencies. This chapter investigates the potential microbes such as bacteria, viruses, fungi, and parasites present in HWW along with the diseases associated and methods of treatment used. Due to the indiscriminate release of antibiotics from hospitals, HWW serves as a hotspot for emergence of antibiotic-resistance genes (ARGs) and antibiotic-resistance bacteria. This chapter discusses the ARGs occurrence in HWW, their prevalence in the environment, the molecular tools used for identification, and different mechanisms of horizontal gene transfer. Thus better understanding of the microbiology of HWW could further help in development of advanced treatment technologies for effective removal of microbes and their bioproducts (toxins and infectious nucleic acid) from HWW and contaminated water.