Mycoses最新文献

Background: Microsporum audouinii has resurged recently. Infections with the dermatophyte are difficult to treat, which raises the question if we treat M. audouinii infections with the most effective antifungal (AF) agent.

Objectives: The aims of this study was to investigate an outbreak of tinea capitis (TC) in Denmark, address the challenges in outbreak management and to conduct two reviews regarding previous outbreaks and minimal inhibitory concentration (MIC).

Methods: We used Wood's light, culture, direct microscopy, and PCR for screening and antifungal susceptibility testing (AFST) for treatment optimization. We performed two reviews to explore M. audouinii outbreaks and MIC values using broth microdilution method.

Results: Of 73 screened individuals, 10 had confirmed M. audouinii infections. Clinical resistance to griseofulvin was observed in 4 (66%) cases. While previous outbreaks showed high griseofulvin efficacy, our study favoured terbinafine, fluconazole and itraconazole in our hard-to-treat cases. AFST guided the choice of AF. Through the literature search, we identified five M. audouinii outbreaks, where differences in management included the use of Wood's light and prophylactic topical AF therapy. Terbinafine MIC values from the literature ranged from 0.002 to 0.125 mg/L.

Conclusion: Use of Wood's light and preventive measurements were important for limiting infection. The literature lacked MIC data for griseofulvin against M. audouinii, but indicated sensitivity for terbinafine. The clinical efficacy for M. audouinii treatment was contradictory favouring both terbinafine and griseofulvin. AFST could have a key role in the treatment of difficult cases, but lack of standardisation of AFST and MIC breakpoints limits its usefulness.

The present study analyses the clinical characteristics of patients diagnosed with cutaneous fusarium through a systematic review of cases reported in literature. A total of 39 cases were included, of which 53% were men, 30% were women, and in 17% the sex was not specified. The age ranged from 5 to 85 years. Most cases were reported in Brazil, followed by Japan and United States of America. The most common agent was Fusarium solani, in 37.5% of the patients. Most of the affected individuals had acute myeloid leukaemia and some of the predisposing factors, which included induction chemotherapy, febrile neutropenia, and bone marrow transplantation. The clinical topography of the lesions was located in 27.5% and disseminated in 72.5%, with the most observed clinical feature outstanding the presence of papules and nodules with central necrosis in 47% of the cases. Longer survival was demonstrated in those treated with more than three antifungals. It is concluded that cutaneous fusarium is a complex and challenging clinical entity, infection in patients with leukaemias underscores the need for thorough care to decrease morbidity and mortality.

Background: Bacterial aggregation has been shown to occur in synovial fluid which are resistant to high concentrations of antibiotics. Yet the propensity of Candida spp. to form aggregates is unknown.

Objective: To assess the ability of numerous Candida spp. to form synovial fluid aggregates and the clinical ramifications of the aggregates.

Methods: Nine different Candidal prosthetic joint infection clinical isolates were evaluated for their ability to form aggregates at static and dynamic conditions and their resistance to high concentrations of amphotericin. Furthermore, the ability of tissue plasminogen activator (TPA) to disrupt the aggregates and enhance amphotericin activity was assessed.

Results: The results show that all species of Candida spp. evaluated formed aggregates in synovial fluid under dynamic conditions that were resistant to amphotericin. Yet no aggregates formed in tryptic soy broth under any conditions or in synovial fluid under static conditions. As well, when TPA was combined with amphotericin there was a statistically significant decrease (p < .005) in the amount of colony forming units per mL for all Candidal species evaluated. Interestingly, for Candida krusei there was no colony forming units observed after exposure to TPA and amphotericin.

Conclusion: Our findings suggest that Candidal species form synovial fluid aggregates that are resistant to high dose amphotericin similar to those that occur with bacteria. However, the varying ability of the different Candida spp. to form hyphae and pseudohyphae compared to yeast cells may have direct impacts on the hardiness of the aggregates and thereby have clinical ramifications with respect to treatment durations.

Background: Candida auris, a multidrug-resistant fungal pathogen, has received considerable attention owing to its recent surge, especially in South America, which coincides with the ongoing global COVID-19 pandemic. Understanding the clinical and microbiological characteristics of outbreaks is crucial for their effective management and control.

Objective: This retrospective observational study aimed to characterize a C. auris outbreak at a Peruvian referral hospital between January 2021 and July 2023.

Methods: Data were collected from hospitalized patients with positive C. auris culture results. Microbiological data and antifungal susceptibility test results were analysed. Additionally, infection prevention and control measures have been described. Statistical analysis was used to compare the characteristics between the infected and colonized patients.

Results: Thirty-three patients were identified, mostly male (66.7%), with a median age of 53 years. Among them, 18 (54.5%) were colonized, and 15 (45.5%) were infected. Fungemia was the predominant presentation (80%), with notable cases of fungemia in tuberculosis patients with long-stay devices for parenteral anti-tuberculosis therapy. Seventy-five percent of the isolates exhibited fluconazole resistance. Echinocandins were the primary treatment, preventing fungemia recurrence within 30 days. Infected patients had significantly longer hospital stays than colonized patients (100 vs. 45 days; p = .023). Hospital mortality rates were 46.7% and 25% in the infected and fungemia patients, respectively. Simultaneous outbreaks of multidrug-resistant bacteria were documented.

Conclusions: This study underscores the severity of a C. auris outbreak at a referral hospital in Peru, highlighting its significant impact on patient outcomes and healthcare resources. The high prevalence of fluconazole-resistant isolates, leading to prolonged hospital stay and high mortality rates, particularly in cases of fungemia, underscores the critical need for effective infection prevention and control strategies.

Background: Candida vulturna is an emerging pathogen belonging to the Metshnikowiaceae family together with Candida auris and Candida haemulonii species complex. Some strains of this species were reported to be resistant to several antifungal agents.

Objectives: This study aims to address identification difficulties, evaluate antiungal susceptibilities and explore the molecular mechanisms of azole resistance of Candida vulturna.

Methods: We studied five C. vulturna clinical strains isolated in three Colombian cities. Identification was performed by phenotypical, proteomic and molecular methods. Antifungal susceptibility testing was performed following CLSI protocol. Its ERG11 genes were sequenced and a substitution was encountered in azole resistant isolates. To confirm the role of this substitution in the resistance phenotype, Saccharomyces cerevisiae strains with a chimeric ERG11 gene were created.

Results: Discrepancies in identification methods are highlighted. Sequencing confirmed the identification as C. vulturna. Antifungal susceptibility varied among strains, with four strains exhibiting reduced susceptibility to azoles and amphotericin B. ERG11 sequencing showed a point mutation (producing a P135S substitution) that was associated with the azole-resistant phenotype.

Conclusions: This study contributes to the understanding of C. vulturna's identification challenges, its susceptibility patterns, and sheds light on its molecular mechanisms of azole resistance.

Background: There is a concerning rise in antifungal-resistant dermatophytosis globally, with resistance to terbinafine conferred by point mutations in the squalene epoxidase (SQLE) gene.

Objectives: Report changes in the prevalence and profile of SQLE mutations in onychomycosis patients in the United States.

Methods: A longitudinal cohort study of toenail samples was collected from suspected onychomycosis patients over an 18-month period from 2022 to 2023. Samples were submitted from across the United States and subjected to multiplex real-time polymerase chain reactions for dermatophyte detection, with further screening of SQLE mutations at four known hotspots (393^Leu, 397^Phe, 415^Phe and 440^His).

Results: A total of 62,056 samples were submitted (mean age: 57.5 years; female: 60.4%). Dermatophytes were detected in 38.5% of samples, primarily Trichophyton rubrum complex (83.6%) and T. mentagrophytes complex (10.7%). A survey of SQLE mutations was carried out in 22,610 dermatophyte samples; there was a significant increase in the prevalence of SQLE mutations between the first quarter of 2022 and the second quarter of 2023 (29.0 to 61.9 per 1000 persons). The Phe397Leu substitution was the predominant mutation; Phe415Ser and His440Tyr have also emerged which were previously reported as minor mutations in skin samples. The temporal change in mutation rates can be primarily attributed to the Phe415Ser substitution. Samples from elderly patients (>70 years) are more likely to be infected with the T. mentagrophytes complex including strains harbouring the Phe415Ser substitution.

Conclusion: The prevalence of SQLE mutations among onychomycosis patients with Trichophyton infections may be underestimated. Older individuals may have a higher risk.

Background: Kerion is a severe type of tinea capitis that is difficult to treat and remains a public health problem.

Objectives: To evaluate the epidemiologic features and efficacy of different treatment schemes from real-world experience.

Methods: From 2019 to 2021, 316 patients diagnosed with kerion at 32 tertiary Chinese hospitals were enrolled. We analysed the data of each patient, including clinical characteristics, causative pathogens, treatments and outcomes.

Results: Preschool children were predominantly affected and were more likely to have zoophilic infection. The most common pathogen in China was Microsporum canis. Atopic dermatitis (AD), animal contact, endothrix infection and geophilic pathogens were linked with kerion occurrence. In terms of treatment, itraconazole was the most applied antifungal agent and reduced the time to mycological cure. A total of 22.5% of patients received systemic glucocorticoids simultaneously, which reduced the time to complete symptom relief. Furthermore, glucocorticoids combined with itraconazole had better treatment efficacy, with a higher rate and shorter time to achieving mycological cure.

Conclusions: Kerion often affects preschoolers and leads to serious sequelae, with AD, animal contact, and endothrix infection as potential risk factors. Glucocorticoids, especially those combined with itraconazole, had better treatment efficacy.

Background: Candida auris is an emerging multidrug-resistant yeast, frequently causing outbreaks in health care facilities. The pathogen persistently colonises human skin and inanimate surfaces such as catheters, aiding to its spread. Moreover, colonisation is a risk factor to develop invasive infection.

Objectives: We investigated 61 C. auris strains isolated from non-sterile human body sites (n = 53) and the hospital environment (n = 8), originating from four different centres in a single Brazilian state.

Materials and methods: Antifungal susceptibility testing (AFST) against common antifungals was performed, and resistance-associated genes were evaluated. Genetic relatedness was investigated with short tandem repeat (STR) genotyping and validated with whole-genome sequencing (WGS) single nucleotide polymorphism (SNP) analysis.

Results: Antifungal susceptibility testing demonstrated that all isolates were susceptible to azoles, echinocandins and amphotericin B. No mutations were detected in ERG11 and FKS1 genes. With STR typing, isolates were allocated to clade IV and appeared closely related. This was confirmed by WGS SNP analysis of 6 isolates, which demonstrated a maximal difference of only 41 SNPs between these strains. Furthermore, the Brazilian isolates formed a distinct autochthonous branch within clade IV, excluding recent introductions from outside the country. A molecular clock analysis of clade IV isolates from various countries suggests that early in the previous century there was a unique event causing environmental spread of a C. auris ancestor throughout the Latin-American continent, followed by human introduction during the last decades.

Conclusion: We report the emergence of C. auris patient colonisation in multiple centres by fluconazole-susceptible clade IV close-related strains in Pernambuco State, Brazil.

Background: Tinea faciei is a relatively uncommon dermatophyte infection. The studies, which included clinical forms, and isolated species of dermatophytes, are limited.

Materials and methods: This retrospective study aims to determine the causative organism, clinical characteristics, treatments and outcomes of patients with tinea faciei attending the dermatologic clinic, Siriraj Hospital, from 1 January 2017 to 30 September 2021. Demographic data, clinical presentations, isolated dermatophyte species, treatments and outcomes were collected and analysed.

Results: A total of 151 tinea faciei cases were observed. Trichophyton rubrum (48.6%), Trichophyton mentagrophytes complex (22.2%) and Microsporum canis (18.1%) were common causative agents. Tinea faciei was commonly detected in females (64.9%) with a history of pets (54.6%). Clinical presentations often involved plaques and scales on the cheeks. Among patients with lesions on the cheek, mycological cure was observed significantly less often compared to those without cheek lesions. Patients with other concurrent skin or nail infections, a history of topical steroids and a history of previous fungal infection had a slightly longer duration of mycological cure than those without factors. Recurrent infection was found in 33.3%. Male, history of previous fungal infection, and lesions on the cheeks were significantly associated with recurrent infection.

Conclusions: Fungal infection of the face was commonly found in women and patients with pets. The most common pathogen that caused tinea faciei was T. rubrum. Topical antifungal treatments could be used with favourable outcomes. The history of past infection and lesion on the cheeks should be carefully assessed to be vigilant for recurrent infection.

Background: Tinea faciei, a specific dermatophytosis that affects the glabrous skin of the face, not only causes physical discomfort but also leads to greater psychological distress. Tinea faciei is a public health concern.

Objectives: To analyse the epidemiological characteristics, responsible dermatophyte species and clinical features of tinea faciei in Hangzhou.

Methods: Data were obtained from the Laboratory Information System of the Mycology Laboratory and Medical Information System at a hospital in Hangzhou. Isolates were identified based on their macroscopic appearance and microscopic morphology.

Results: Tinea faciei was diagnosed in 701 patients, involving 359 males and 342 females, aged between 2 months and 97 years. In total, 499 isolates (71.18%) were identified as Trichophyton rubrum. Anthropophilic isolates were identified in 297 (82.73%) males and 207 (60.53%) females (p < .01). Among patients with anthropophilic dermatophytes infection, 447 (88.69%) were adults. Zoophilic dermatophytes were isolated in 57 (15.88%) males and 130 (38.01%) females (p < .01), among whom 108 (57.75%) were children.

Conclusions: Anthropophilic dermatophytes, especially T. rubrum, were the predominant cause of tinea faciei, while zoophilic dermatophytes were the most prevalent in children. Compared with men, women may be more susceptible to zoophilic dermatophytes.