Current Medical Mycology最新文献

Background and purpose: Human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) is a serious risk factor for oral candidiasis (OC). In this regard, the present study aimed to investigate the frequency of Candida species collected from the oropharyngeal cavity of HIV-positive patients and the sensitivity of these isolates to antifungal drugs.

Materials and methods: Oral samples were collected from 169 HIV-positive patients. In addition to culture-based methods, a molecular assay via the polymerase chain reaction-restriction fragment length polymorphism method was applied to identify isolates using the MspI restriction enzyme. The disk diffusion method determined the susceptibility of isolated yeasts to common antifungal drugs according to the CLSI M44-A2 protocol.

Results: In total, 81 participants (47.92%) were positive for OC, and Candida albicans was the most prevalent yeast (53.98%). The median age of patients was 36 years old (IQR=10.5; 17-59), and it was found that women are 27% more susceptible to HIV-associated OC (OR=1.268; 95% CI: 0.685-2.348). Patients who received antifungal therapy had a 97.3% reduced chance for OC (OR: 0.027; 95% CI: 0.008-0.091; P-value: 0.000). Antifungal therapy reduced the risk of OC by 97.3% (OR=0.027; 95% CI=0.008-0.091; P=0.000), and antiretroviral therapy decreased the chance of OC 4.42 times (OR=4.423; 95% CI=1.697-11.528; P=0.002). The resistance rates for antifungals, namely fluconazole, ketoconazole, itraconazole, amphotericin B, and nystatin were 15.93%, 8.85%, 7.96%, 5.31%, and 4.42%, respectively.

Conclusion: Although several decades have passed since the emergence of HIV/AIDS, little information is available about fungal colonization and infections in this population. Further investigations are suggested using novel and reference molecular identification methods, such as matrix-assisted laser desorption ionization time-of-flight mass spectrometry and sequencing, respectively. In addition, more reliable methods for antifungal susceptibility testing are recommended.

Background and purpose: Tinea incognita (TI), or the other equivalent tinea atypica, is a term used to declare the atypical presentation of dermatophyte infections caused by the administration of steroids or other immunosuppressive medications which modulate the local and systemic immune response. It can mimic other dermatoses; hence making diagnostic challenges for dermatologists. Tina incognita may be misdiagnosed as many dermatoses. Based on previous studies, corticosteroids may cause different clinical manifestations of dermatophytes that might be very different from those that are commonly described.

Materials and methods: This narrative review was conducted using PubMed and Scopus databases. Search terms included "Tinea incognita" and "Atypical dermatophytosis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, reviews, and case reports. The search was restricted to articles written in the English language from 2006 to Feb 01, 2023. Moreover, duplicate articles and non-available full-text articles were excluded. The extracted data of the search results were retrieved in this study. The morphological patterns, prevalence, sight of infection, and causative agents were also described.

Results: Prevalence of different patterns of TI were recorded as 50% (431 out of 862 cases) for eczema-like lesions followed by psoriasis-like and 6.61% (57 out of 862) for parapsoriasis-like pattern. Moreover, each of the rosacea-like and pyoderma-like lesions equally accounted for 4.98 % of cases (43 out of 862). In addition, the prevalence of causative agents was reported as follows: Trichophyton rubrum accounted for 247 isolates (40%) as the most prevalent, followed by Trichophyton mentagrophytes (n=152, 24%) and Microsporum canis (n=119, 19%).

Conclusion: Tinea incognita is a great mimicker; hence, dermatologists should obtain a full medical history of the patients to make correct diagnoses. It is vital to encourage an exact identification of the etiological agent according to the internal transcribed spacer sequencing in some uncertain cases. This review highlights the importance of mycological tests and fast diagnosis of TI, especially in cases of atypical skin lesions, to choose appropriate treatment and avoid the spread of drug-resistant species.

Background and purpose: In recent years, the inclusion of Candida albicans on the list of infections that pose a threat due to drug resistance has urged researchers to look into cutting-edge and effective antifungal medications. In this regard, the current study investigated the probable mode of action of allyl isothiocyanate (AITC) against Candida albicans.

Materials and methods: In this study, planktonic assay, germ tube inhibition assay, adhesion, and biofilm formation assay were performed to check the growth and virulence factors. Furthermore, ergosterol assay, reactive oxygen production analysis, cell cycle analysis, and quantitative real-time polymerase chain reaction analysis were performed with the aim of finding the mode of action. A biomedical model organism, like a silkworm, was used in an in vivo study to demonstrate AITC anti-infective ability against C. albicans infection.

Results: Allyl isothiocyanate completely inhibited ergosterol biosynthesis in C. albicans at 0.125 mg/ml. Allyl isothiocyanate produces reactive oxygen species in both planktonic and biofilm cells of C. albicans. At 0.125 mg/ml concentration, AITC arrested cells at the G2/M phase of the cell cycle, which may induce apoptosis in C. albicans. In quantitative real-time polymerase chain reaction analysis, it was found that AITC inhibited virulence factors, like germ tube formation, at 0.125 mg/ml concentration by downregulation of PDE2, CEK1, TEC1 by 2.54-, 1.91-, and 1.04-fold change, respectively, and upregulation of MIG1, NRG1, and TUP1 by 9.22-, 3.35-, and 7.80-fold change, respectively. The in vivo study showed that AITC treatment successfully protected silkworms against C. albicans infections and increased their survival rate by preventing internal colonization by C. albicans.

Conclusion: In vitro and in vivo studies revealed that AITC can be an alternative therapeutic option for the treatment of C. albicans infection.

Background and purpose: Onychomycosis is a very common cosmopolitan onychopathy. It affects the fingers and toes, which are important organs of function and socialization. They can cause physical and psychological discomfort. In this regard, the present study aimed to assess the impact of onychomycosis on the quality of life of patients.

Materials and methods: This prospective, cross-sectional, observational study was carried out in the parasitology-mycology laboratory of the Avicenne Military Hospital in Marrakesh, Morocco, over 5 months between June and October 2022. The study population was all the patients referred to the laboratory for mycological examination of a nail lesion suspected of onychomycosis of the hands and/or feet.

Results: Onychomycosis was confirmed in 50 patients. Pain, nail thickening, and dyschromia were the most commonly reported symptoms (56%). Onychomycosis had an impact on at least one of the socio-economic, emotional, or functional aspects of the lives of affected patients. More than half (56%) of participants felt embarrassed by the appearance of their nails, 40% hid them, and 28% had a complex about them. The functional aspect was the most bothersome and the time spent on nail care concerned the patients (56%), as well as the discomfort reported when wearing shoes (40%). Women were more worried about the need to hide their nails. A duration of onychomycosis evolution of over 5 years was associated with the highest response rate to the questionnaire (66%).

Conclusion: Although onychomycosis is not a fatal pathology, it significantly reduces the quality of life of affected patients. There is a need to raise the level of awareness of the general population and, above all, of the medical professionals to ensure comprehensive management of onychomycosis.

Background and purpose: Species identification of Malassezia using culture-dependent methods is time-consuming due to their fastidious growth requirements. This study aimed to evaluate a rapid and accurate molecular method in order to diagnose the pityriasis versicolor (PV) and identify Malassezia species from direct clinical samples.

Materials and methods: Skin scraping or tape samples from patients with PV and healthy volunteers as the control group were collected. Diagnosis of PV was confirmed by direct microscopic examination. The DNA extraction was performed according to the steel-bullet beating method. Polymerase chain reaction-restriction fragment length polymorphism assay using HhaI restriction enzyme was applied for the identification and differentiation of Malassezia species.

Results: The PCR method was able to detect Malassezia in 92.1% of specimens which were also confirmed with microscopic examination. Statistically, a significant association was observed between the results of the two assays (P < 0.001). Moderate agreement was identified between the two methods to diagnose the PV in both populations (Kappa: 0.55). Considering microscopic examination as the gold standard method for confirmation of PV, the sensitivity, specificity, positive predictive value, and negative predictive value values of the PCR assay for recognition of PV were 85%, 75%, 92%, and 60%, respectively. M. globosa and M. restricta were the most prevalent species isolated from patients.

Conclusion: In this study, the two-step molecular method based on the amplification of the D1/D2 domain and digestion of the PCR product by one restriction enzyme was able to diagnose and identify Malassezia directly from clinical samples. Consequently, it can be said that the molecular-based method provides more facilities to identify fastidious species, such as M. restricta.

Mucormycosis (previously called zygomycosis) is a diverse group of increasingly recognized and frequently fatal mycotic diseases caused by members of the class zygomycetes. Mucormycosis is around 80 times more common in India, compared to other developed countries, with a frequency of 0.14 cases per 1,000 population. The most frequent causative agent of mucormycosis is the following genera from the Order Mucorales Rhizopus, Mucor, Rhizomucor, Absidia, Apophysomyces, Cunninghamella, and Saksenaea. The major risk factors for the development of mucormycosis are diabetic ketoacidosis, deferoxamine treatment, cancer, solid organ or bone marrow transplantations, prolonged steroid use, extreme malnutrition, and neutropenia. The common clinical forms of mucormycosis are rhino-orbital-cerebral, pulmonary, cutaneous, and gastrointestinal. During the second wave of COVID-19, there was a rapid increase in mucormycosis with more severity than before. Amphotericin B is currently found to be an effective drug as it is found to have a broad-spectrum activity and posaconazole is used as a salvage therapy. Newer triazole isavuconazole is also found effective against mucormycosis. This study aimed to review various studies on the laboratory diagnosis and treatment of mucormycosis.

Background and purpose: Morbidity and mortality of opportunistic fungal infections in COVID-19 patients are less studied and defined. The patients receiving immunosuppressive therapy, broad-spectrum antibiotics, corticosteroids, and invasive and non-invasive ventilation are the high-risk groups.

Materials and methods: The demographic profile as well as clinical and radiological findings of all the patients with COVID-19 suspected of Mucormycosis (MM) were recorded. The tissue samples from all the patients were sent for microbiological (KOH mount and culture) and histopathological analysis for confirmation of MM.

Results: In total, 45 COVID-19 patients suspected of MM were included in the study and MM was confirmed in 42 patients. The mean age of the patients was 50.30±14.17 years with a female: male ratio of 1.1:1. The most common symptom was headache (52.38%) followed by purulent nasal discharge (38.09%) and facial pain in 33.33% of the cases. The ocular symptoms included a diminution of vision (33.33%) and redness of the eye (2.38%). The most common site of involvement was rhino-orbital (42.85%) followed by sinonasal (23.80%) and rhino cerebral (19.04%). Majority (38.09%) of the patients were diagnosed with stage II of Rhino-orbital-cerebral Mucormycosis (ROCM) based on radiology. A history of diabetes mellitus and steroids was present in 97.61% and 85.71% of the cases, respectively. Moreover, KOH was positive for MM in 97.61% of the cases while the culture was positive in only 35.71% of the cases. In addition, on histopathology, MM was confirmed in 64.28 % of the cases. Mixed growth with Aspergillus species and Rhizopus species was observed in 14.28% of the cases in culture and 11.90% of the cases in histopathology test. Furthermore, angioinvasion was found in 23.80% of the cases according to the histopathology test.

Conclusion: Based on the results, the most common conditions associated with MM in COVID-19 patients were diabetes mellitus and steroid therapy. A high level of clinical suspicion aided with diagnostic tests, including KOH mount, culture, histopathology, and radiology which helped the early detection of opportunistic fungal infection in COVID-19 patients to ensure timely treatment.

Background and purpose: Dermatophytosis is one of the most prevalent zoonotic diseases. Increased resistance of dermatophytosis-causing pathogens against antidermatophytic agents highlights the need for alternative medicine with higher efficiency and lower side effects. In the present study, the in vitro antifungal activities of different concentrations of Gracilaria corticata methanol extract against Trichophyton mentagrophytes, Microsporum canis, and Microsporum gypseum were assessed and their efficacy was evaluated in rat dermatophytosis models.

Materials and methods: The broth microdilution and well diffusion methods were used to determine the in vitro antidermatophytic activity. The in vivo study was carried out using 40 dermatophytosis-infected adults male Wistar rats. The animals were divided into 4 groups (5% and 10% G. corticata ointment, terbinafine, and Vaseline) and treated with ointment until complete recovery. The percentage of wound closure was calculated for each group.

Results: The results revealed that G. corticata methanol extract was effective to varying extents against the tested dermatophytes. The highest inhibitory activity of G. corticata was found against T. mentagrophytes with minimum inhibitory concentration and minimum fungicidal concentration values of 4 and 9 µg mL^-1, respectively. The in vivo experiment revealed that 10% G. corticata ointment significantly accelerated skin lesions reduction and completely cured M. gypseum, T. mentagrophytes, and M. canis infections after 19, 25, and 38 days, respectively.

Conclusion: The methanol extract of G. corticata exhibited significant antifungal activity in vitro and in vivo, suggesting that it could be used as an alternative to antidermatophytic therapy in a dose-dependent manner.

Candida auris is an emerging pathogen predominantly isolated from immunocompromised patients, hospitalized for a long time. It inhabits the skin surfaces of patients causing ear, wound, and systemic infections; if not treated properly, it could lead to severe mortality. Apart from being a skin pathogen, C. auris colonizes the surfaces of medical devices. Medical devices are hospital tools and components often utilized for the diagnosis and treatment of diseases associated with human skin. The mechanism of survival and persistence of C. auris on medical devices has remained unclear and is a serious concern for clinicians. The persistence of C. auris on medical devices has deterred its effective elimination, hindered the treatment of infections, and increased its antifungal resistance. Evidence has shown that a few surface molecules on the cell wall of C. auris and the extracellular matrix of the biofilm are responsible for its persistence and exist as enablers. Due to the increased cases of ear, skin, and systemic infections as well as death resulting from the spread of C. auris in hospitals, there is a need to study these enablers. This review focused on the identification of the enablers and aimed to evaluate them in relation to their ability to induce persistence in C. auris. In order to reduce the spread of or completely eliminate C. auris and its enablers in hospitals, the efficacy of disinfection and sterilization methods were compared.

Background and purpose: Wickerhamomyces myanmarensis is a new opportunistic yeast previously named Pichai myanmarensis, which belongs to the order Saccharomycetales. Since its discovery, one environmental isolate of W. myanmarensis has been reported from Myanmar, and one clinical sample from Iran.

Case report: We report a case of bloodstream infection related to an implantable venous access port. W. myanmarensis was isolated from patient's blood after chemotherapy, which was meant to control and heal T-cell lymphoblastic lymphoma. Broth dilution minimum inhibitory concentrations were performed according to the CLSI M27-A3 document. The patient recovered with intravenous voriconazole and was discharged with the recommended prescription of oral voriconazole as a maintenance drug.

Conclusion: So far, only one case of W. myanmarensis fungemia has been reported in the world in 2019. This is the second case of bloodstream infection with this yeast from a patient undergoing chemotherapy in Iran.