فهرست مطالب
Current Medical Mycology
Volume:8 Issue: 2, Jun 2022
- تاریخ انتشار: 1401/08/01
- تعداد عناوین: 9
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Pages 1-7Background and Purpose
Vulvovaginal candidiasis (VVC) is considered the most common mucosal infection caused by Candida species. Azoles were considered the firstline treatment for VVC or recurrent vulvovaginal candidiasis (RVVC) in both healthy and immunocompromised populations. Recently, azole-resistant isolates, especially among non-albicans Candida samples have been encountered. This study aimed to evaluate the antifungal susceptibility profile of Candida spp. isolated from VVC or RVVC patients and assess the molecular resistance mechanism of Candida spp. to azole and echinocandin.
Materials and MethodsPoint mutation analysis was performed on the ERG11 and FKS candidate genes of azole- and caspofungin-resistant Candida albicans and Candida glabrata isolates. Real-time polymerase chain reaction was performed to gain insight into the differential expression of ERG11 mRNA.
ResultsVariations in the amino acid D116E were observed in fluconazole- and itraconazole-resistant C. albicans strains, and changes in amino acid E517Q were observed only in fluconazole-resistant C. albicans strains. No polymorphisms were observed in the complete sequence alignment of the ERG11 gene in one azole-resistant C. glabrata isolate. The mutation triggered the changes in the amino acid serine in the reference gene FKS1 by the leucine at position 642 (S642L) of the isolates.
ConclusionIn patients with persistent or recurrent infection, the choice of an antifungal agent is often challenging and requires monitoring of the antifungal susceptibility of the colonizing strain. C. albicans and C. glabrata isolates can be resistant to azole and caspofungin antifungal agents without mutations in the ERG 11 and HS1 regions of the FKS1 gene.
Keywords: Azole, Echinocandin, Candida species, mutations, Vulvovaginal candidiasis -
Pages 8-15Background and Purpose
Invasive candidiasis is a life-threatening condition that kills a large number of immunocompromised patients each year worldwide. We used postantifungal 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 MethodsWe 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.
ResultsThe FLC had no detectable post-antifungal effect independent of antifungal concentration and resembled drug-free FLC (control). Significant variations in the postantifungal 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).
ConclusionOur 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.
Keywords: anidulafungin, candida albicans, combination regimen, Post-antifungal effect -
Pages 16-24Background 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 MethodsThis 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.
ResultsA 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).
ConclusionA 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.
Keywords: Aspergillus, Aspergillosis, COVID-19, Influenza, Pneumonia, Outcomes -
Pages 25-31Background 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 MethodsThis 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.
ResultsIn 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%).
ConclusionIn 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 testingresults, only 7.2% of the strains were resistant to fluconazole. It would be beneficial tomonitor the ICU patients who are at high risk of invasive Candida infection.
Keywords: Candida colonization index, Candidiasis, ICU, Pediatric, PICU -
Pages 32-39Background 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 MethodsSamples 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).
ResultsIn 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 higherthan other Candida species.
ConclusionThe C. albicans isolated from HIV-positive individuals secreted higheramounts of exoenzymes, and can cause oropharyngeal candidiasis and become a sourceof candidiasis for the host.
Keywords: AIDS patients, Candida species, Enzyme Activity, Oral candidiasis -
Pages 40-44Background 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 MethodsNanoparticles 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.
ResultsPhysical 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).
ConclusionGF-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.
Keywords: dermatophytes, Griseofulvin, Nanoparticles, ZnO -
Pages 45-48Background 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 realtime 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.
ConclusionThe clinicians must consider tuberculosis and mucormycosis tests when confronted with an uncontrolled diabetic patient with clinical symptoms of hemoptysis, fever, and cavitary lesions.
Keywords: Diabetes, Mucormycosis, pulmonary tuberculosis -
Pages 49-54Background 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.
ConclusionThis 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.
Keywords: COVID-19, Mucormycosis, Syncephalastrum racemosum -
Pages 55-58Background 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.
ConclusionC. 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.
Keywords: Cutaneous cryptococcosis, Cryptococcus neoformans, thymic carcinoma, type B3 thymoma