sanaz yaalimadad

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.

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.

Oral candidiasis (OC) has been noticed as a common mucous membrane infection in immunocompromised patients such as that diabetes. This study, focused on the genotyping of Candida albicans and enzymatic activities of Candida species recovered from oral mucosa among diabetes patients and healthy individuals.

Specimens were obtained from oral mucosa of One‑hundred and sixty patients with type 2 diabetic and 108 healthy individuals. All isolates were definitely identified by ribosomal DNA (rDNA) gene sequencinghHydrophobicity, hemolytic activities of Candida species and genotypes of C. albicans were determined through polymerase chain reaction (CA‑INT).

, Eighty eight (55%) samples out of 160, were positive for Candida species in diabetic patients. Moreover, 79.5% (70/88) and 20.5% (18/88) isolates belonged to the C. albicans and non‑albicans Candida species respectively. Three genotypes of C. albicans have recovered in diabetic patients: genotype A (71.42%), B (21.42%), and C (7.14%). In healthy individuals, 42.6% (46/102) Candida species recovered from oral cavity, with the highest prevalence of genotype A (76.6% of C. albicans). Additionally, hydrophobicity and hemolytic activities from Candida species were significantly greater in diabetes patients than healthy nondiabetic subjects.

Collectively, C. albicans was the most causative agent isolated from diabetes patients and non‑diabetes healthy individuals. Genotype A, as the most remarkable genotype, should be mentioned in both groups. Higher potential hydrophobicity and hemolytic activities of Candida species in diabetic patients compared to healthy cases suggest these features triggering pathogenicity of OC in diabetes patients.

Due to the emergence of multidrug-resistant Candida species, the discovery of new antifungal agents with minimum side effects is essential. The aim of this study was to investigate the antifungal activity of caprylic acid and nano-encapsulated caprylic acid against C. albicans as well as their effect on the expression of EFG1 gene.

In this laboratory trial study, the minimum inhibitory concentration (MIC) of caprylic acid and nano-encapsulated caprylic acid against C. albicans was evaluated at various concentrations (400-625 and 1.3-50 μL/mL, respectively). Real time-PCR was performed to assess the expression level of EFG1 gene. Cytotoxicity effect of caprylic acid and nano-encapsulated caprylic acid was evaluated on SW480 cell line using MTT test.

Antifungal activity findings displayed that MIC90 and MIC50 values of caprylic acid were 500 and 450 μg/mL, respectively, whereas MIC90 and MIC50 values of nano-encapsulated caprylic acid were 6.2 and 3.1 μg/mL, respectively. The expression of EFG1 gene significantly decreased in the groups treated with caprylic acid and nano-encapsulated caprylic acid compared to the control group. According to the cytotoxicity evaluation findings, the viability of cells treated with caprylic acid was significantly higher than that of cells exposed to nano-encapsulated caprylic acid.

According to the obtained results, nano-encapsulated caprylic acid successfully inhibited C. albicans growth at a lower concentration compared to caprylic acid. Overall, it was found that nano-encapsulated caprylic acid is a promising antifungal agent against Candida species; however, further studies are needed to be performed about nano-encapsulation of caprylic acid.