Current Medical Mycology最新文献

Background and purpose: Invasive candidiasis is a life-threatening condition that kills a large number of immunocompromised patients each year worldwide. We used post-antifungal effect studies to analyze the activities of anidulafungin (AFG), as a clinically crucial antifungal drug, amphotericin B (AMB), and fluconazole (alone and in combinations) against FLC-susceptible and -resistant Candida albicans (C. albicans) isolates obtained from the cancer patients.

Materials and methods: We tested the phenomenon of post antifungal effects of FLC, AMB, AFG, and combinations of FLC+AFG, AFG+AMB, and FLC+AMB against 17 C. albicans isolates obtained from the oral cavity of cancer patients. Isolates that had not been exposed to antifungals, served as a control group. Colony counts were performed at 0, 2, 4, 6, and 24 h after a brief (1 h) exposure to antifungal.

Results: The FLC had no detectable post-antifungal effect independent of antifungal concentration and resembled drug-free FLC (control). Significant variations in the post-antifungal effect were observed when all AMB and AFG were compared to FLC. The combination of AFG and AMB with FLC resulted in effective activity compared to FLC alone. Combination regimens were rated as indifferent in general. Interestingly, low dosages of the AFG displayed increasing fungistatic action as it approached a fungistatic endpoint against C. albicans isolates (n=17).

Conclusion: Our findings suggested that brief exposure to AFG, in combination with FLC and AMB, at low concentrations of the medicines utilized, could be effective in the evaluation and optimization of new dosage regimens to manage candidiasis. However, future studies will determine the clinical utility of our findings.

Background and purpose: Cryptococcosis is a known opportunistic infection. Thymomas are known to cause immune dysregulation. We describe an atypical case of cutaneous cryptococcosis in a patient with acquired T cell immunodeficiency that has been found to be secondary to a type B3 thymoma with progression to carcinoma.

Case report: A 63-year-old male presented with a chronic skin lesion confirmed as Cryptococcus neoformans on biopsy and an incidental mediastinal mass found during infectious work-up for the notable cluster of differentiation 4 (CD4)+ lymphopenia. This led to the diagnosis of a type B3 thymoma requiring resection. The cryptococcal lesion was treated successfully with azole therapy.

Conclusion: C. neoformans is an opportunistic infection rarely associated with isolated T cell immunodeficiency due to thymomas. A multidisciplinary approach and understanding of the pathogenicity of cryptococcus and the immunological effect of thymic dysfunction are paramount to diagnosis and treatment.

Background and purpose: Diabetes and immunosuppressive diseases have been reported as increased risk factors for developing invasive pulmonary tuberculosis and mucormycosis.

Case report: We presented here a case of a 55-year-old uncontrolled diabetic male with rhinosinus mucormycosis and pulmonary TB coinfection. Maxillary and ethmoid sinus involvement was observed in paranasal computed tomography. His chest computed tomography showed tree in the bud sign and cavitary lesions in the lungs. Mycobacterium tuberculosis was confirmed through molecular diagnosis using a real-time polymerase chain reaction assay. The nasal cavity biopsy revealed the fungal elements (aseptate hyphae) and confirmed mucormycosis infection. Amphotericin B liposomal, teicoplanin, and tazobactam were administered to treat the mucormycosis. The patient was successfully treated with a recommended four-drug regimen for TB without any adverse reaction.

Conclusion: The clinicians must consider tuberculosis and mucormycosis tests when confronted with an uncontrolled diabetic patient with clinical symptoms of hemoptysis, fever, and cavitary lesions.

Background and purpose: Influenza A and SARS-CoV-2 are risk factors for invasive pulmonary aspergillosis. Both influenza-associated pulmonary aspergillosis and COVID-19-associated pulmonary aspergillosis result in high mortality and poor clinical outcomes. No prospective study has so far compared the features, treatment, and outcomes of influenza-associated pulmonary aspergillosis and COVID-19-associated pulmonary aspergillosis within a similar time frame. Therefore, this study aimed to determine the frequency, risk factors, and outcomes of invasive pulmonary aspergillosis in critically ill patients with influenza, COVID-19, and community-acquired pneumonia.

Materials and methods: This prospective study included adult patients with pneumonia and was conducted at The Aga Khan University Hospital in Karachi, Pakistan. Patients were divided into three groups, including community-acquired pneumonia, influenza pneumonia, and COVID-19 pneumonia. The data collected included information on demographic characteristics, comorbidities, clinical features, laboratory results, treatment, and outcomes.

Results: A total of 140 patients were included in this study. These included 35 (25%), 70 (50%), and 35 (25%) patients with community-acquired pneumonia, influenza pneumonia, and COVID-19 pneumonia, respectively. In addition, 20 (14.2%) patients were found to have invasive aspergillosis, of whom 10/35 (28.5%), 9/70 (12.8%), and 1/35 (2.8%) patients were in the COVID-19, influenza, and community-acquired pneumonia groups, respectively. Moreover, nine (90%) COVID-19-associated pulmonary aspergillosis patients required vasopressors, compared to three (33%) patients with influenza-associated pulmonary aspergillosis (P=0.020). In total, seven (70%) COVID-19-associated pulmonary aspergillosis patients required invasive mechanical ventilation compared to four (44%) influenza-associated pulmonary aspergillosis patients (P=0.37). The mean±SD length of hospital stay was highest in the COVID-19-associated pulmonary aspergillosis patients (18.3±7.28 days) compared to influenza-associated pulmonary aspergillosis patients (11.7±5.34 days) (P=0.036). The number of deaths in influenza-associated pulmonary aspergillosis and COVID-19-associated pulmonary aspergillosis patients was three (33.3%) and five (50%), respectively (P=0.526).

Conclusion: A higher proportion of patients with COVID-19 developed invasive aspergillosis compared to those with influenza. Although the mortality rate in COVID-19-associated pulmonary aspergillosis was comparable to that in influenza-associated pulmonary aspergillosis patients, COVID-19-associated pulmonary aspergillosis patients had a significantly longer stay in the hospital.

Background and purpose: Invasive mucormycosis is a rare mycosis that affects most cases of uncontrolled diabetes and has a high mortality rate. Patients with COVID-19 are at high risk of developing invasive mucormycosis due to the consumption of anti-inflammatory drugs such as corticosteroids and dexamethasone. Rhizopus species followed by Rhizomucor spp. and Mucor spp. are the main common etiological agents of rhino-orbital mucormycosis. Therefore, this study aimed to present a case of mucormycosis due to Syncephalastrum racemosum in a diabetic patient with COVID-19 for the first time in Iran.

Case report: A 73-year-old diabetic female was referred to Ayatollah Rouhani Hospital in Babol, Iran, with a confirmed COVID-19 diagnosis, based on positive RT-PCR and computed tomography of the lungs. She has received methylprednisolone due to severe lung complications. Nasal involvement and left orbital swelling were observed 20 days after the hospitalization. By sinus endoscopic surgery, debridement was done and histopathology indicated wide hyphae (without septa). The sequenced PCR products displayed Syncephalastrum racemosum. In the antifungal susceptibility test, amphotericin B showed good activity against S. racemosum and the patient survived with timely treatment.

Conclusion: This is the first case report of rhino-orbital mucormycosis due to S. racemosum in COVID-19 patient; therefore, S. racemosum can be considered one of the etiological factors of rhino-orbital mucormycosis in COVID-19 cases.

Background and purpose: Dermatophytoses is an important type of skin disease caused by dermatophytes. The long-term treatment of this disease with standard antifungal agents may be improved through the application of nanotechnology. This study aimed to prepare nanoparticles of griseofulvin with zinc oxide and assess its antifungal action.

Materials and methods: Nanoparticles of griseofulvin with zinc oxide (GF-ZnO NPs) were prepared. Physical characteristics of new preparation and antidermatophytic action against two species of dermatophytes (Trichophyton mentagrophytes and Trichophyton verrucosum) were investigated. Testing of two species was considered a primary test for antifungals of griseofulvin nanoparticles.

Results: Physical examination indicated that GF-ZnO NPs had typical nanoparticle characteristics. A new formulation showed effective inhibitory action against two fungal species with higher efficiency than that of griseofulvin. T. mentagrophytes required a higher MIC value (0.0625 µg/mL) of GF-ZnO NPs than that required by T. verrucosum (0.031 µg/mL).

Conclusion: GF-ZnO NPs revealed an effective action against dermatophytes compared to griseofulvin alone. Nanoparticles containing griseofulvin may be used in the development of a novel drug for the treatment of dermatophytosis.

Background and purpose: Rhinosinusitis (RS) is a clinical and radiological diagnosis that rarely reaches a proper infective etiological diagnosis. The most dreaded fact about invasive fungal rhinosinusitis is its poor prognosis in immunocompromised patients with a 60-80% mortality rate. The present study highlights and compares the various diagnostic techniques to establish a fungal etiological diagnosis in clinically suspected cases of RS from nasal biopsy specimens, with the emphasis on the molecular diagnostic approach.

Materials and methods: This prospective study included a total of 34 clinically suspected cases of RS who had recently undergone functional endoscopic sinus surgery (FESS)/biopsy from nasal polyps. Various laboratory methods (microbiological and histopathological) were utilized, including direct microscopic examination of clinical samples and fungal culture isolation. The molecular detection method of polymerase chain reaction (PCR) from clinical samples was also explored simultaneously. Serum immunoglobulin-E (IgE) testing of patients was also performed.

Results: Out of 34 clinically suspected RS cases, fungal etiology was established in a total of 18 cases, 17 of whom were culture-proven. A total of 15 and 14 culture-proven cases were also detected on direct microscopic examination by potassium hydroxide (KOH) mount and histopathological staining, respectively. One case was additionally identified by molecular method. Aspergillus flavus complex was the most common pathogen isolated in culture. Allergic fungal RS was the most common type, followed by acute and chronic invasive types among all fungal RS cases.

Conclusion: Accurate and prompt etiological diagnosis of fungal RS is still lagging with fewer options for quick results. Although microscopy and culture isolation can't be replaced, PCR is a sensitive and specific method that should be incorporated as a supplementary tool for the early diagnosis and management, considering the delayed growth of fungi.

Background and purpose: Taurolidine is active against a wide variety of micro-organisms, including bacteria and fungi. Mucormycosis is one of the life-threatening opportunistic fungal infections, especially in immunocompromised patients. Currently, the emergence of Mucormycosis during the COVID-19 pandemic raises public health concerns regarding untoward morbidity and mortality among SARS-CoV-2 patients. It is well-known that delayed and inappropriate antifungal therapy leads to increased morbidity and mortality. This study aimed to investigate the in-vitro antifungal activity of taurolidine to evaluate its effects against clinical isolates of Mucorales.

Materials and methods: This study included previously collected clinical Mucorales isolates. The minimum in vitro inhibitory concentration (MIC) of amphotericin B, caspofungin, voriconazole, posaconazole, and itraconazole was determined using the broth microdilution method.

Results: All clinical isolates showed full sensitivity to amphotericin B. Posaconazole MIC range from 8 μg/mL to 0.032‎ μg/mL. The MIC range of voriconazole and caspofungin were determined to be 2-8 µg/mL and 0.5-16 µg/mL, respectively. Growth of the isolates was entirely inhibited in 1000 µg/mL concentration of taurolidine. In microscopic observations, morphological effects on hyphal growth were observed at 500 µg/mL concentration.

Conclusion: In conclusion, this is an updated experience of using taurolidine against Mucorales. However, our in-vitro findings need to be confirmed in well-designed clinical trials aimed at treating invasive Mucormycosis infections.

Background and purpose: Routine identification of Candida species and knowledge of antibiotic susceptibility patterns can prevent diagnostic delays and help clinicians choose appropriate empirical therapies. This study aimed to identify and speciate Candida isolates from bloodstream infections and evaluate their epidemiological profile and antibiotic susceptibility pattern in a tertiary care hospital in North India.

Materials and methods: Blood samples were cultured in the Department of Microbiology of a tertiary care hospital from January 2019 to May 2021, and the samples which showed growth of Candida species (spp.) were included in this study. Candida isolates were initially characterized by conventional techniques. Further identification and antifungal susceptibility testing were performed using Vitek 2 compact automated system. Data analysis was performed using the SPSS software (Version 25.0).

Results: Candida spp. were isolated from a total of 116 blood samples, 60.92% of which belonged to males. The majority (43.10%) of isolates were obtained from 0-1-month-old neonates, followed by infants (16.38%) and children in the age range of 1-17 years (16.38%). Only 6.89% of isolates were obtained from adults older than 18 years. Candida tropicalis (26.72%) was the most common species, followed by Candida pelliculosa (19.83%), Candida albicans (17.24%), Candida parapsilosis (14.66%), Candida famata (9.48%), and Candida krusei (9.48%). Other isolated species included Candida lusitaniae, Candida sphaerica, and Candida inconspicua. Out of 116 isolates, 101 isolates were subjected to Vitek 2 susceptibility testing. Overall, 21.78% (22/101) of Candida isolates were found to be resistant/intermediate. Among C. albicans isolates, resistance was observed only against voriconazole (20%) and fluconazole (5%); however, among non- albicans Candida species (NAC), resistance was observed against flucytosine (16.04%), followed by fluconazole (14.81%), voriconazole (3.70%), and caspofungin (3.70%).

Conclusion: Non-albicans Candida spp. predominated over Candida albicans in causing bloodstream infections and were found to be more resistant to antifungals. Continuous surveillance is necessary to monitor changes in epidemiological and resistance patterns.

Background and purpose: Candida albicans (C. albicans) is the most common human pathogen owing to the most virulence factors. It seems that extracellular hydrolytic enzymes play a key role in C. albicans pathogenicity. The present study aimed to assess the susceptibility and enzymatic activity of pathogenic C. albicans isolates exposed to the Syzygium aromaticum (S. aromaticum) essential oil.

Materials and methods: S. aromaticum oil was characterized using gas chromatography-mass spectrometry (GC-MS). The broth microdilution technique (CLSI, M27-A3) was used to determine the minimum inhibitory concentration (MIC) of test compounds. Furthermore, before and after treatment with S. aromaticum essential oil, the yeasts were analyzed regarding the proteinase (Prz), hemolysin (Hz), and phospholipase (Phz) production/activity.

Results: β-caryophyllene (12.76%) was found to be the major constituent in the essential oil after eugenol (84.64%). Only one isolate of C. albicans showed the antifungal resistance to fluconazole. All isolates were susceptible to S. aromaticum essential oil with MIC of 625-1250 μg/ml. S. aromaticum oil represented the best antifungal effect against C. albicans at MIC 1000 μg/ml. The mean±SD enzyme activity of C. albicans not exposed to S. aromaticum essential oil was obtained at 0.55±0.03, 0.73±0.04, and 0.61±0.05 for proteinase, hemolysin, and phospholipase, respectively. The activities of these enzymes were reduced significantly (P<0.05) to 0.33±0.06, 0.40±0.04, and 0.16±0.03 for phospholipase, proteinase, and hemolysin, respectively, after the yeasts were subjected to S. aromaticum essential oil.

Conclusion: The present study aimed to determine the ability of S. aromaticum essential oil to prevent the growth of C. albicans and decrease their enzymatic activity. As a natural antifungal agent, S. aromaticum can be utilized in pharmaceutical systems.