Current Medical Mycology最新文献

Background and purpose: The three most common causes of vaginitis are bacteria, yeast, and Protozoa. Candida albicans is one of the most common causes of vaginitis and commonly affects millions of females with different signs and symptoms. Secretion of exoenzymes from Candida species plays an important role in virulence and pathogenesis. Increasing our knowledge about the pathogenesis of candidiasis could help to design new anti-Candida drugs. This study aimed to evaluate the phospholipase, esterase, and hemolysin activities of the vaginal Candida isolates and their correlation with the presence of vulvovaginal candidiasis.

Materials and methods: In total, 119 Candida albicans isolates from vaginal candidiasis were enrolled in the study. Egg yolk agar, Tween 80 opacity medium, and blood agar plate assays were used for the determination of phospholipase, esterase, and hemolytic activities, respectively.

Results: Based on the findings, 110 (92.44%) isolates showed phospholipase activity, 93 (78.2%) isolates were esterase producers, and 90 (75.6%) species had hemolytic activity.

Conclusion: This study showed that most of the tested isolates had different enzymatic patterns. Discrimination of variations in the production of these exoenzymes among different Candida isolates may depend on Candida spp. pathogenicity and could be responsible for the severity of symptoms among the patients.

Background and purpose: Interest in probiotic use for respiratory allergies has increased. In this regard, the present study aimed to evaluate the effect of cell wall extract of Saccharomyces boulardii on Aspergillus fumigatus as an allergenic fungus and its effectiveness in reducing inflammatory cytokines in A549 cells sensitized with A. fumigatus conidia.

Materials and methods: Cell wall of S. boulardii was prepared and challenged by A. fumigatus conidia at various concentrations. Secretory protease activity was tested using the Casein method. The A. fumigatus allergen 1 (Asp f1) gene expression was calculated by quantitative real-time polymerase chain reaction (qRT-PCR). In another experiment, qRT-PCR was used to examine gene expression of interleukin 13 and interleukin 17 by A549 lung epithelial cells exposed to A. fumigatus conidia and treated with different concentrations of S. boulardii cell wall extract.

Results: Saccharomyces boulardii cell wall extract significantly reduced the protease activity of A. fumigatus at concentrations of 10 and 20 mg/ml (P<0.05). The Asp f1 gene expression was significantly down-regulated in each concentration of S. boulardii cell wall extract (P<0.05). Aspergillus fumigatus conidia upregulated the expression of IL-13 and IL-17 in A549 cells, and S. boulardii cell wall extract could downregulate the expression of the mentioned cytokines at concentrations of 10 and 20 mg/ml (P<0.05).

Conclusion: According to the results, it can be concluded that S. boulardii cell wall extract could be a candidate for IL-13- and IL-17-induced Aspergillus-mediated allergy and asthma therapies. Nevertheless, future studies need to be conducted on the safety of S. boulardii cell wall extract in vivo and its effects on other arms of allergic hypersensitivity.

Background and purpose:  Onychomycosis is a common nail infection characterized by the discoloration, thickening, and detachment of nails. This study aimed to provide valuable insights into this pathology by assessing its prevalence, clinical aspects, related comorbidities, and causative agents in patients from a Moroccan population.

Materials and methods:  This retrospective study was conducted on 1,606 subjects at the Mycology-Parasitology laboratory of the National Institute of Hygiene in Rabat, Morocco, over five years (2016-2020). Nail samples were collected from both fingernails and toenails and processed through microscopic examination and culture. The incubated tubes were kept at a temperature range of 28-30°C for 4-5 weeks.

Results:  Onychomycosis was mycologically confirmed in 1,794 samples (93.24%). It occurred commonly in the 41-60 age group, with a higher incidence among females (74.53%). Diabetes, alongside other chronic diseases, was prevalent among patients with underlying conditions, comprising 131 cases (40.56%). Disto-lateral subungual onychomycosis emerged as the most prevalent clinical presentation, comprising 1,536 cases (79.92%). Fingernails primarily affected by yeasts, notably Candida albicans, accounted for 565 cases (29.80%), while toenails were predominantly impacted by dermatophytes, primarily Trichophyton rubrum (n=1,230, 64.87%). Mixed infections exclusively featured yeasts and dermatophytes, predominantly T. rubrum and C. albicans, which accounted for 79 (4.40%) cases. The study explored the influence of molds, yielding insights into their rarity in onychomycosis.

Conclusion:  These findings hold significant implications for the clinical management and diagnosis of onychomycosis, particularly in patients with underlying chronic conditions. Further epidemiological studies across Morocco are needed for meaningful comparisons.

Background and purpose: In diabetic foot ulcers, if fungal agents, such as Candida species penetrate the cutaneous or depth of the ulcer, it can increase the wound severity and make it more difficult to heal.

Materials and methods: A cross-sectional study was performed on 100 diabetic patients with a foot ulcer from December 2019 to November 2020 in northern Iran. Patient data and wound grades were recorded in a questionnaire. Candida infection was confirmed by direct microscopic examination and culture. To identify the causative agent, polymerase chain reaction-restriction fragment length polymorphism using MspI enzyme and the partial amplification of hyphal wall proteins (HWP1) gene were performed.

Results: Mean age of the participants was 62.1 ± 10.8 years old, and 95% of them had type 2 diabetes. Moreover, more than 83% of them had diabetes for a duration of 10 years. In addition, 59% of the patients were male, and 66% > of them had poor education levels. Besides, 99% of them were married, and 52% were rural. Furthermore, 95% of the participants had neuropathic symptoms and 88% used antibiotics. The HbA1C level was > 9% in 69% of them, and the mean ulcer grade of the patients was 2.6±1.05. Candida infection was detected in 13% of the deep tissue and 7% of the tissue surrounding the wound. The predominant Candida isolate was C. parapsilosis (71.5%) and C. albicans (14.3%). Infections caused by filamentous fungi were not detected. There was a statistically significant relationship between Candida infection and gender, rural lifestyle, HbA1C, and ulcer grade.

Conclusion: Mycological evaluations of diabetic foot ulcers are often ignored. The present study revealed that C. parapsilosis is the most common causative agent of deep-seated foot ulcer infection in these patients and may require specific treatment. Therefore, more attention of physicians to Candida infections, early diagnosis, and prompt treatment can help accelerate wound healing and prevent amputation.

Candida species can produce a variety of clinical manifestations, and several non-albicans species of Candida, including Candida auris, have been linked to the rise of invasive fungal infections with high rates of treatment failure. Nosocomial outbreaks and high mortality rates in healthcare institutions across the globe have been associated with C. auris, an emerging infectious yeast that was initially discovered in the ear canal of an elderly Japanese patient in 2009. The fact that C. auris has been found on six continents after it was initially isolated has raised serious concerns among scientists and healthcare practitioners. At present, healthcare facilities lack defined protocols for the effective prevention and control of C. auris infections, as well as appropriate treatment alternatives. This leads to frequent therapeutic failures and complicates the eradication of C. auris infection in healthcare facilities. Studies on C. auris in South India are often limited, and healthcare workers urgently need to be made aware of infections caused by it in order to assess its impact and possible implications for the healthcare system. This study aimed to report seven patients hospitalized in our center who developed C. auris infections with varying clinical manifestations.

Background and purpose: Fusarium species are commonly resistant to many antifungal drugs. The limited therapeutic options available have led to a surge of research efforts aimed at discovering novel antifungal compounds in recent decades. This study aimed to assess the in vitro antifungal activity of plant-based biosynthesized selenium nanoparticles (Se NPs) and six comparators against a set of clinical Fusarium strains.

Materials and methods: In vitro antifungal activity of Se NPs synthesized using plant extracts of Allium paradoxum, Crocus caspius, Pistacia vera L. hull, Vicia faba L. hull and Heracleum persicum, as well as six common antifungal drugs, namely voriconazole, itraconazole, amphotericin B, posaconazole, natamycin, and caspofungin were evaluated against 94 clinical Fusarium strains using broth microdilution according to Clinical and Laboratory Standards Institute guideline.

Results: The obtained results were intriguing since all five types of biosynthesized Se NPs demonstrated significantly higher antifungal activity, compared to antifungal drugs. It was found that Se NPs synthesized by V. faba L. hull extract (0.03 μg/ml) had the lowest geometric mean minimum inhibitory concentration value followed by Se NPs synthesized by P. vera L. hull extract (0.25 μg/ml), A. paradoxum extract (0.39 μg/ml), C. caspius extract (0.55 μg/ml), and H. persicum extract (0.9 μg/ml).

Conclusion: Plant-based Se NPs demonstrated supreme antifungal activity and could be considered promising antifungal agents for Fusarium infections. However, tests, such as toxicity and in vivo tests are needed before the product can be used in clinical settings.

Background and purpose: Emergence of fungi as a pathogenic threat presents a significant challenge to public health, notably in intensive care units (ICUs) and among immunocompromised patients. Various factors, including sepsis-induced barrier disruptions, immune system dysfunction, and extremes of age, contribute to increased susceptibility to fungal infections. Hospital practices, such as prolonged surgeries, broad-spectrum antibiotic use, and invasive procedures, further exacerbate the risk. Fungal bloodstream infections, particularly those caused by Candida albicans, rank among the most common hospital-acquired infections, leading to substantial morbidity and mortality. The global rise in invasive candidiasis, particularly due to non-albicans Candida species, presents challenges in the diagnosis and treatment due to nonspecific symptoms and emerging antifungal resistance. Nanotechnology interventions particularly by utilizing green synthesized copper nanoparticles could possibly provide a novel solution to combat microbial colonization, biofilm formation, and drug resistance. This study aimed to assess the prevalence of candidemia, identify the distribution of causative Candida species, and understand their susceptibility patterns to commonly used antifungal agents for effective management in ICU settings. Additionally, the study sought to explore the in vitro anti-Candida activity of green copper nanoparticles synthesized using Euphorbia milii des moul extract.

Materials and methods: This study was conducted at Microbiology Laboratory of Maharishi Markandeshwar Institute of Medical Sciences and Research from January to December 2022, focused on ICU patients suspected of bloodstream infections. Blood samples were collected aseptically and processed using BD BACTECTM culture vials. Identification of organisms was performed via the Vitek-2 system by confirming candidemia with positivity in both blood samples. After that antifungal susceptibility testing was also performed against Clinical and Laboratory Standards Institute recommended antifungal drug using Vitek 2 system. G-CuNPs were synthesized using E. milii Des moul extract and possessed for physiochemical characterization. The anti-Candida activity of G-CuNPs was evaluated through the MTT assay and time kill assay. After that generation of intracellular reactive oxygen species and DNA degradation were evaluated to understand its mechanism.

Results: This study identified a candidemia rate of 7.3% (58/789). Age and gender analysis revealed higher Candida colonization rates in individuals above 60 years old and females. Antifungal sensitivity profiling indicated notable resistance to fluconazole (27.59%) and voriconazole (25.86%). Synthesizing G-CuNPs using E. milii des moul extract represents a novel approach exhibiting significant fungicidal potency against

Background and purpose: The mainstay of treatment for COVID-19-associated mucormycosis was liposomal Amphotericin B. Other antifungal agents, such as posaconazole and isavuconazole, were used as well. The Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing recommend broth microdilution methods for antifungal susceptibility testing. In this regard, the present study aimed to see what potency and zone diameters correlate with the gold standard broth microdilution method.

Materials and methods: All the isolates were identified by matrix-assisted laser desorption ionization-time-of-flight. In total, 127 isolates of 83 Rhizopus oryzae complex and 44 isolates of Rhizopus microsporus complex were selected. Anti-fungal susceptibility testing by disc diffusion and E-test was performed on Mueller Hinton Agar and compared with the CLSI broth microdilution method of Anti-fungal susceptibility testing.

Results: Percentage agreement was found to be more in the case of the E test than the disc diffusion method. In the case of R. oryzae, posaconazole had 98.79% agreement with broth microdilution followed by Isavuconazole (97.59%), Itraconazole (96.38%), and Amphotericin B (91.56%).

Conclusion: Disc diffusion correlates well with broth microdilution, although its correlation is weaker when compared to the E test. Effective concentration of Amphotericin B discs for antifungal susceptibility testing depends on the specific Rhizopus species.

Background and purpose: The COVID-19 pandemic may be an aggravating risk factor for the delay of the diagnoses of serious illnesses, such as oral squamous cell carcinoma, as well as poor management of patients with underlying morbidities, the onset of oral lesions, and antifungal susceptibility to opportunistic fungal infections. Oral candidiasis is one of the most common oral features of COVID-19.

Case report: This study aimed to report an 83-year-old female diagnosed with oral carcinoma who developed oropharyngeal candidiasis after falling ill with COVID-19. In late 2020, this patient was hospitalized for COVID-19 pneumonia. A fissured tongue with white scars appeared after the COVID-19 recovery that caused pain, dysphasia, and dysarthria. The sequencing result based on the internal transcribed spacer rDNA region confirmed Candida glabrata. Its antifungal susceptibility showed susceptibility to nystatin, fluconazole, and caspofungin, but resistance to the other azoles and amphotericin B.

Conclusion: Risk of fungal infections, such as Candida seems to be high in patients with severe COVID-19, mainly affecting the oral mucosa. However, whether they are directly attributed to COVID-19 or other surrounding factors is unknown.

Background and purpose: The current study aimed to report a multiplex polymerase chain reaction (PCR) assay as a monitoring technique to differentiate aflatoxigenic from non-aflatoxigenic strains of Aspergillus flavus isolated from pistachio orchards soil.

Materials and methods: In total, 25 A. flavus strains were isolated from soil samples of pistachio orchards. To test the strains for Aflatoxin B₁ (AFB₁)-producing ability, thin-layer chromatography (TLC) was used and the amounts of AFB₁ were measured by high-performance liquid chromatography (HPLC). Multiplex PCR was used as a genome-based method to detect genes responsible for AFB₁ production by A. flavus and the results were analyzed in terms of speed and specificity of detection. A set of four primers was designed specifically for the omtA, omtB, ver-1, and aflR genes which are commonly present in aflatoxin biosynthetic pathways.

Results: The AFB₁ production by the A. flavus strains ranged from 0 to 321 ρg/μl. Four-band patterns of the primer sets were observed only in AFB₁-producing A. flavus strains. Moreover, 18 out of the 25 strains showed all four bands belonging to omtA, omtB, ver-1, and aflR, whereas 7 strains did not display omtA, or aflR-related bands, in non-toxigenic and low toxin-producing A. flavus.

Conclusion: The multiplex PCR is a supplementary strategy to current conventional mycotoxin analytical techniques, such as TLC and HPLC. It could be used as an efficient method to differentiate aflatoxigenic from non-aflatoxigenic strains of A. flavus. This achievement is crucial to minimize fungal contamination of food, feed, and agricultural commodities, thereby reducing the risk of subsequent aflatoxin consumption.