Mycopathologia最新文献

Aspergillus fumigatus is a saprophytic fungal pathogen that causes opportunistic infections in animals and humans. Azole resistance has been reported globally in human A. fumigatus isolates, but the prevalence of resistance in isolates from animals is largely unknown. A retrospective resistance surveillance study was performed using a collection of clinical A. fumigatus isolates from various animal species collected between 2015 and 2020. Agar-based azole resistance screening of all isolates was followed by in vitro antifungal susceptibility testing and cyp51A gene sequencing of the azole-resistant isolates. Over the 5 year period 16 (11.3%) of 142 A. fumigatus culture-positive animals harbored an azole-resistant isolate. Resistant isolates were found in birds (15%; 2/13), cats (21%; 6/28), dogs (8%; 6/75) and free-ranging harbor porpoise (33%; 2/6). Azole-resistance was cyp51A mediated in all isolates: 81.3% (T-67G/)TR₃₄/L98H, 12.5% TR₄₆/Y121F/T289A. In one azole-resistant A. fumigatus isolate a combination of C(-70)T/F46Y/C(intron7)T/C(intron66)T/M172V/E427K single-nucleotide polymorphisms in the cyp51A gene was found. Of the animals with an azole-resistant isolate and known azole exposure status 71.4% (10/14) were azole naive. Azole resistance in A. fumigatus isolates from animals in the Netherlands is present and predominantly cyp51A TR-mediated, supporting an environmental route of resistance selection. Our data supports the need to include veterinary isolates in resistance surveillance programs. Veterinarians should consider azole resistance as a reason for therapy failure when treating aspergillosis and consider resistance testing of relevant isolates.

Background: During the COVID-19 pandemic-associated mucor epidemic, acute antifungal drug shortage necessitated the exploration of other antifungals based on culture sensitivity. Itraconazole is a cheap, safe, and effective antifungal in sensitive cases.

Methodology: We enrolled itraconazole-sensitive COVID-19-associated mucormycosis during the mucormycosis pandemic. After the intensive phase course of liposomal amphotericin B, Itraconazole was offered in susceptible cases during the maintenance phase along with standard of care. These patients were clinically and radiologically followed for 6 months.

Results: We enrolled 14 patients (Male: Female-11:3) of Rhino-orbito-cerebral mucormycosis (ROCM) which included 12 diabetics. All patients had facial swelling, orbital swelling, visual impairment, and headache. MRI showed involvement of bilateral sinus (10/14), orbital extension (13/14), cavernous sinus (5/14), cerebral part of the internal carotid artery (3/14), and brain infarcts (4/14). All 14 patients showed sensitivity to Itraconazole with 12 having minimum inhibitory concentration (MIC) ≤ 1 μg/ml and 2 having MIC ≤ 2 μg/ml. Follow-up at 6 months showed clinical improvement in the majority (11/14) and radiological improvement in six out of seven scanned patients.

Conclusion: Our study shows the potential therapeutic role of oral Itraconazole in ROCM.

Treatment-resistant dermatophytosis caused by the members of the Trichophyton mentagrophytes/Trichophyton interdigitale species group (TMTISG) is increasing worldwide. We aimed to determine the prevalence of TMTISG in patients with dermatophytosis in two centers from north of Iran and detect the possible mutations in the squalene epoxidase (SQLE) gene in relevant terbinafine (TRB) resistant pathogenic isolates. From November 2021 to December 2022, 1960 patients suspected to dermatophytosis and referred to two mycology referral laboratories in the north of Iran were included in the study. Identification of all dermatophyte isolates was confirmed by RFLP of rDNA internal transcribed spacer (ITS) regions. Antifungal susceptibility testing against five common antifungals using the CLSI-M38-A3 protocol was performed. The TMTISG isolates resistant to TRB, were further analyzed to determine the possible mutations in the SQLE gene. Totally, 647 cases (33%) were positive for dermatophytosis of which 280 cases (43.3%) were identified as members of TMTISG. These were more frequently isolated from tinea corporis 131 (44.56%) and tinea cruris 116 (39.46%). Of 280 TMTISG isolates, 40 (14.3%) were resistant to TRB (MIC ≥ 4 µg/mL), all found to be T. indotineae in ITS sequencing. In SQLE sequencing 34 (85%) of TRB-resistant isolates had coincident mutations of Phe³⁹⁷Leu and Ala⁴⁴⁸Thr whereas four and two isolates had single mutations of Phe³⁹⁷Leu and Leu³⁹³Ser, respectively. Overall, the resistance of Iranian TMTISG isolates to TRB greatly occurred by a mutation of Phe³⁹⁷Leu in the SQLE gene as alone or in combination with Ala⁴⁴⁸Thr. Nevertheless, for the occurrence of in vitro resistance, only the presence of Phe³⁹⁷Leu mutation seems to be decisive.

The impact of invasive pulmonary aspergillosis (IPA) on non-neutropenic critically ill patients in intensive care units (ICU) has been demonstrated in recent decades. Furthermore, after the start of the COVID-19 pandemic, COVID-19 associated with pulmonary aspergillosis (CAPA) has become a major concern in ICUs. However, epidemiological data from different regions are scarce. We evaluated the prevalence and clinical-epidemiological data of IPA in patients with COVID-19 requiring mechanical ventilation (MV) in the ICU ("severe COVID-19") and non-COVID ICU patients in MV of a tertiary hospital in the southern region of Brazil. Eighty-seven patients admitted between June 2020 and August 2022 were included; 31 with severe COVID-19. For the diagnosis of IPA or CAPA, algorithms including host factors and mycological criteria (positive culture for Aspergillus spp., immunoassay for galactomannan detection, and/or qPCR) were utilized. The overall incidence of IPA and CAPA in our ICU was 73 cases/1000 ICU hospitalizations. Aspergillosis occurred in 13% (4/31) of the COVID-19 patients, and in 16% (9/56) of the critically ill patients without COVID-19, with mortality rates of 75% (3/4) and 67% (6/9), respectively. Our results highlight the need for physicians enrolled in ICU care to be aware of aspergillosis and for more access of the patients to sensitive and robust diagnostic tests by biomarkers detection.

A 50-year-old man, previously diagnosed with pulmonary tuberculosis and lung cavities, presented with symptoms including fever, shortness of breath, and cough. A pulmonary CT scan revealed multiple cavities, consolidation and tree-in-bud in the upper lungs. Further investigation through direct examination of bronchoalveolar lavage fluid showed septate hyphae with dichotomous acute branching. Subsequent isolation and morphological analysis identified the fungus as belonging to Aspergillus section Nigri. The patient was diagnosed with probable invasive pulmonary aspergillosis and successfully treated with a three-month oral voriconazole therapy. Phylogenetic analysis based on partial β-tubulin, calmodulin and RNA polymerase second largest subunit sequences revealed that the isolate represents a putative new species related to Aspergillus brasiliensis, and is named Aspergillus hubkae here. Antifungal susceptibility testing demonstrated that the isolate is resistant to itraconazole but susceptible to voriconazole. This phenotypic and genetic characterization of A. hubkae, along with the associated case report, will serve as a valuable resource for future diagnoses of infections caused by this species. It will also contribute to more precise and effective patient management strategies in similar clinical scenarios.

Introduction: The global spread of Trichophyton indotineae presents a pressing challenge in dermatophytosis management. This systematic review explores the current landscape of T. indotineae infections, emphasizing resistance patterns, susceptibility testing, mutational analysis, and management strategies.

Methods: A literature search was conducted in November 2023 using Embase, PubMed, Scopus, and Web of Science databases. Inclusion criteria covered clinical trials, observational studies, case series, or case reports with T. indotineae diagnosis through molecular methods. Reports on resistance mechanisms, antifungal susceptibility testing, and management were used for data extraction.

Results and discussion: A total of 1148 articles were identified through the systematic search process, with 45 meeting the inclusion criteria. The global spread of T. indotineae is evident, with cases reported in numerous new countries in 2023. Tentative epidemiological cut-off values (ECOFFs) suggested by several groups provide insights into the likelihood of clinical resistance. The presence of specific mutations, particularly Phe397Leu, correlate with higher minimum inhibitory concentrations (MICs), indicating potential clinical resistance. Azole resistance has also been reported and investigated in T. indotineae, and is a growing concern. Nevertheless, itraconazole continues to be an alternative therapy. Recommendations for management include oral or combination therapies and individualized approaches based on mutational analysis and susceptibility testing.

Conclusion: Trichophyton indotineae poses a complex clinical scenario, necessitating enhanced surveillance, improved diagnostics, and cautious antifungal use. The absence of established clinical breakpoints for dermatophytes underscores the need for further research in this challenging field.

Pneumocystis pneumonia is a serious lung infection caused by an original ubiquitous fungus with opportunistic behavior, referred to as Pneumocystis jirovecii. P. jirovecii is the second most common fungal agent among invasive fungal infections after Candida spp. Unfortunately, there is still an inability to culture P. jirovecii in vitro, and so a great impairment to improve knowledge on the pathogenesis of Pneumocystis pneumonia. In this context, animal models have a high value to address complex interplay between Pneumocystis and the components of the host immune system. Here, we propose a protocol for a murine model of Pneumocystis pneumonia. Animals become susceptible to Pneumocystis by acquiring an immunocompromised status induced by iterative administration of steroids within drinking water. Thereafter, the experimental infection is completed by an intranasal challenge with homogenates of mouse lungs containing Pneumocystis murina. The onset of clinical signs occurs within 5 weeks following the infectious challenge and immunosuppression can then be withdrawn. At termination, lungs and bronchoalveolar lavage (BAL) fluids from infected mice are analyzed for fungal load (qPCR) and immune response (flow cytometry and biochemical assays). The model is a useful tool in studies focusing on immune responses initiated after the establishment of Pneumocystis pneumonia.