Current Medical Mycology最新文献

Background and purpose: Oropharyngeal candidiasis is the most prevalent opportunistic fungal infection in patients with human immunodeficiency virus (HIV) as well as other immunodeficiency disorders, which is caused by various Candida species, mostly Candida albicans. Studies have shown that Candida isolates differ in their pathogenicity. These variations are attributed to virulence factors, host characteristics, and the target tissue. This study aimed to determine and compare the secretion of hydrolytic enzymes in C. albicans and non-albicans Candida species isolated from HIV⁺/AIDS patients and healthy individuals.

Materials and methods: Samples were taken from 201 patients with HIV and 118 healthy individuals. The samples were identified by macroscopic, phenotypic, and molecular methods, and virulence factors were subsequently measured. Statistical differences in enzymatic activity of various Candida isolates were calculated (P<0.0001).

Results: In total, 95 samples (47.20%) from patients and 46 samples (38.90%) from healthy individuals were positive for the growth of different Candida species. There were 39 (41.10%) and 36 (78.30%) C. albicans in patients and healthy individuals, respectively, as well as 56 (58.90%) and 10 (21.70%) non-albicans species in patients and healthy subjects, respectively. All the enzymes produced by Candida species enzymes were at low, medium, and high levels. Hemolysin activity in Candida species isolated from patients was significantly higher, compared to healthy individuals. Moreover, the activity of all C. albicans enzymes in patients was significantly higher than other Candida species.

Conclusion: The C. albicans isolated from HIV-positive individuals secreted higher amounts of exoenzymes, and can cause oropharyngeal candidiasis and become a source of candidiasis for the host.

Background and purpose: This study aimed to evaluate the species distribution and susceptibility pattern of the strains isolated from Candida colonization in pediatric patients staying at pediatric intensive care unit (ICU) and infant ICU of Children's Medical Center in Tehran, Iran.

Materials and methods: This study was conducted in the Children's Medical Center in Tehran, Iran. In total, 440 samples from 56 patients with oral cavity, skin surrounded catheters, and ear, throat, nasal, and urine cultures were collected. All patients were evaluated in terms of Candida colonization on the admission day as well as the days 7, 14, and 28 according to the previous studies. CHROMagar Candida medium was applied for primary/multiple species identification and the isolates were identified by using polymerase chain reaction-based methods to the species-specific complex level. The antifungal susceptibility test was performed according to the Clinical and Laboratory Standards protocol published as M27-A3 and M60 documents.

Results: In total, 136 yeast samples from 26 individuals (30.9%) out of 440 samples were considered colonization. The most prevalent species in IICU was C. albicans (27%, n=20) followed by C. krusei (24 %, n=18) and C. parapsilosis (16%, n=12). In PICU, the predominant species was C. krusei (40%, n=24) followed by C. parapsilosis (18%, n=11) and C. dubliniensis (16%, n=10). Among the 40 tested isolates from both units, fluconazole-resistant isolates (n=11, 8.15%) were determined according to the new breakpoints. In the case of echinocandins, 2 isolates, including C. albicans (n=1) and C. krusei (n=1) were resistant against both caspofungin and anidulafungin (totally 1.48%).

Conclusion: In the present study, since C. krusei is intrinsically-resistance against fluconazole, emphasizing the importance of species-level identification of Candida isolates is outstanding. However, according to the antifungal susceptibility testing results, only 7.2% of the strains were resistant to fluconazole. It would be beneficial to monitor the ICU patients who are at high risk of invasive Candida infection.

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.