Acute invasive fungal rhinosinusitis is a rare infection primarily affecting patients with co-morbidities like immunosuppression and poorly controlled diabetes. Mucormycosis is increasingly being reported in patients with SARS-CoV-2 (COVID-19). However, reports of coinfection of aspergillosis and mucormycosis involving nose, paranasal sinuses, orbit, and brain are rare in literature. We aimed to evaluate the patient demographics, clinical presentation, and management of cases presenting with mixed infection. We carried out retrospective analysis of 12 patients with confirmed diagnosis of mixed invasive fungal infections post-COVID-19 disease out of 70 cases of COVID-19-associated mucormycosis (CAM) presenting to a tertiary-level hospital in North India from May to June 2021. All patients had diabetes mellitus; the mean age was 48 years. The common presenting features were headache, nasal congestion, palatal ulcer, and vision loss accompanied by facial pain and swelling. Two patients developed cerebral abscess during the course of treatment; three patients had concurrent COVID-19 pneumonia. All patients received systemic liposomal amphotericin B and serial surgical debridements. The overall mortality rate was 16.7%. Our study demonstrates that mucormycosis and aspergillosis are angioinvasive mycoses that are clinically and radiologically identical. KOH direct mount of clinical sample showing septate hyphae should be extensively searched for aseptate hyphae after digestion and clearing of the tissue. A high index of suspicion of mixed infection post-COVID-19 and early initiation of liposomal amphotericin B followed by prompt surgical intervention can reduce the overall morbidity and mortality among patients with this condition.
Aspergillus section Nigri, a group of black Aspergillus, has several cryptic species that were recently discovered to be intrinsically resistant to azole antifungals. In this study, susceptibility testing of 35 clinical isolates of Aspergillus tubingensis and Aspergillus welwitschiae in Japan was carried out using microdilution method. Strains tolerant to itraconazole in A. tubingensis (14/17 strains) and A. welwitschiae (6/18 strains) were discovered with hyphal growth and conidial germination above the minimal inhibitory concentration by microscopic observation, while no resistant strain was observed macroscopically. In contrast, no strain with reduced susceptibility to voriconazole, posaconazole, and amphotericin-B was found. Further examination may be required to determine the susceptibility of cryptic species in Aspergillus section Nigri to antifungals.
Neoscytalidium dimidiatum is a common fungus that causes non-dermatophyte dermatomycosis in tropical regions, but there have been no reports of infection with N. dimidiatum in Japan. Here, we report the first isolation of N. dimidiatum from human dermatomycosis in Japan. A 62-year-old healthy Japanese male had been treated with oral terbinafine for tinea pedis diagnosed from a microscopic examination in 2003 with a lesion that was intractable. In 2020, re-identification by sequencing the internal transcribed spacer regions and the D1/D2 domain of the large-subunit (LSU) ribosomal RNA gene revealed that the pathogen was N. dimidiatum. Antifungal susceptibility tests showed that the minimum inhibitory concentration of the drug luliconazole (LLCZ) against the pathogen was 0.00049 µg/mL. The patient’s lesions were cured by topical LLCZ. The clinical course and drug susceptibility suggest that LLCZ is a suitable first-line drug for treatment.
The involvement of the MET5 gene in virulence of Cryptococcus neoformans was examined using the silkworm Bombyx mori infection model. In the virulence assay, the met5Δ mutant showed virulence not significantly different from the wild-type strain, suggesting that the MET5 gene is not essential for full virulence of C. neoformans. The effect of silkworm hemolymph on the survival of the met5Δ mutant was also tested. The C. neoformans met5Δ strain incubated in the silkworm hemolymph for five days remained viable, suggesting that silkworm hemolymph supports survival of the met5Δ strain.
Malassezia are lipophilic yeasts in the skin microbiome that abundantly colonize all parts of human skin except for the soles of the feet. Fungal microbiome analysis of keratotic plugs from the noses of 10 healthy individuals identified Malassezia restricta as the predominant species, followed by Malassezia globosa. Malassezia hyphae were observed in 5 of the 10 individuals. The hyphae were curved and thick-walled with spherical thick-walled and grouped blastoconidia, described as a “spaghetti-and-meatballs” configuration. In this study, we observed Malassezia hyphae in keratotic plugs of healthy subjects, although abundant Malassezia hyphae have previously only been observed in lesional sites of patients with pityriasis versicolor.