Medical mycology最新文献

Onychomycosis has a prevalence varying from 2- 8% at present. The incidence is rising day-by-day worldwide. There are only few studies which have looked into resistance pattern of onychomycosis isolates and so, the present study was planned to study the epidemiology and mycological profile including antifungal susceptibility testing for patients presenting with onychomycosis. The present prospective study (January 2019 to June 2020) was conducted on a total of 92 clinically suspected patients of onychomycosis as per standard mycological techniques. AFST was done for itraconazole, terbinafine, griseofulvin and amphotericin B as per Clinical Laboratory Standard Institute guidelines. Sixty five out of 92 (70.6%) nail samples were positive for fungal etiology on KOH examination while fifty samples grew fungi. Nineteen (38%) were dermatophytes (95% CI: 24.6-51.4%) while 31 (62%) of the isolates were non- dermatophytes (22 non- dermatophytes molds, NDM (95% CI: 30.3-57.7%); and 9 yeast (95% CI: 7.4-28.6%). Onychomycosis was more in males (55.3%) and in age group 41-50 years. Twenty one patients had diabetes. Great toe [40 (61.5%)] as affected nail and DLSO (Distal and lateral onychomycosis) was most common presentation [47(72.3%)]. Among dermatophytes, MIC range was 0.125 -2 μg/ml for terbinafine while it was 0.25-4μg/ml for itraconazole. The MIC50 and MIC90 values were low for amphotericin B while very high for griseofulvin. Among Aspergillus sp and yeast isolates, MIC range was low for terbinafine and itraconazole as 0.03-0.25 μg/ml, 0.06-8 μg/ml, 0.03-0.25 μg/ml, 0.03-0.25 μg/ml respectively. Over the years, the treatment of onychomycosis has been shifted from griseofulvin to terbinafine and itraconazole as has been proven by the study too that MIC values for griseofulvin were very high. It is important to study and generate data regarding the prevalence and antifungal susceptibility profile of not only dermatophytes but also NDMs and yeast which are increasingly isolated, for not only epidemiological purposes but also to plan targeted treatment at optimum doses of antifungals.

Background: Staphylococcus aureus, Pseudomonas aeruginosa; Enterococcal species, Coagulase negative Staphylococci, Acinetobacter species, and Candida species are common blood stream infection (BSI) isolates among ICU cohorts. That Candida species might interact with bacteria at mucosal surfaces to facilitate invasive infections prompts the question as to the degree of co-variance between Candida species versus bacteria among BSI isolates.

Objectives: To estimate the co-variance between Candida species versus each of these five bacteria as BSI isolates among ICU patient cohorts.

Methods: The literature was searched opportunistically for studies reporting ICU patient cohorts listing Candida species among BSI isolates. The associations of the BSI incidence proportion per 100 patients were converted to logits and modelled using ellipse plots.

Results: The median overall BSI incidence proportion was 7.8% (IQR; 4.8%-11.6%). Among 60 cohorts (50 publications), correlation with the incidence proportion of Candidemia was apparent for Acinetobacter species (correlation coefficient = 0.69), Staphylococcus aureus (0.47) and Pseudomonas aeruginosa (0.4) but less so for Coagulase negative Staphylococci (0.37) and Enterococcal species (0.32).

Conclusions: There are various degrees of co-variance between the BSI incidence proportion amongst the five types of bacteria and Candida species among ICU cohorts.

The order Onygenales includes keratinophilic fungi, such as dermatophytes, that can cause onychomycosis. Although dermatophytes are the primary cause of these infections, some non-dermatophytic, keratinophilic onygenalean fungi have been reported as causing nail infections. Other such fungi are frequently isolated as surface contaminants of nails sent for culture, but are not etiologic agents of onychomycosis. Here we introduce a novel onygenalean fungus isolated in the Netherlands from a nail that was suspected to have a fungal infection. As only a single sample was available, etiologic involvement of the fungus could not be assessed; also, since a direct microscopic examination result was not available, the infection status of the nail remains unclear. This fungus, which we describe here as Verweija noviomagensis, is described morphologically with a gymnothecium composed of loose, interwoven hyphae lacking appendages, eight-spored asci, and bright yellow ascospores. A multilocus phylogeny with eight markers classified it within the order Onygenales; however, it was not placed in any defined family within the order.

Elevated intracranial pressure contributes to high mortality in cryptococcal meningitis. We evaluated the association between therapeutic lumbar punctures (LPs) and survival among patients hospitalized with cryptococcal meningitis in the United States. Repeat LPs were associated with lower mortality (HR 0.38; 95%CI, 0.29-0.49) overall, in people with HIV (HR 0.33; 95%CI, 0.21-0.50), in transplant recipients (HR 0.21; 95%CI, 0.08-0.58), and in persons without HIV or transplant (HR 0.44; 95%CI, 0.30-0.64) compared with receipt of only diagnostic LP. Findings support guideline-recommended repeat LP across diverse populations.

Cryptococcus is a deadly opportunistic pathogenic fungus that causes severe infections such as meningitis in immunocompromised patients. Current antifungal therapeutics face the problem of drug resistance and the limitation of high side effects, and there is an urgent need to develop new therapeutic strategies. The growth and pathogenicity of Cryptococcus depend on its complex metabolic network, and by interfering with the metabolic pathways of Cryptococcus, its virulence can be effectively reduced and the immune response of the host enhanced. This paper systematically summarizes the potential therapeutic targets of protein, sugar, lipid, and metal metabolism of Cryptococcus and their mechanisms of action, which provides theoretical support for the development of novel antifungal drugs and brings new hope to the growing problem of fungal infections.

The family Arthrodermataceae, the dermatophytes and allies, ancestrally began with Ascomycetous bifactorial sexual cycles built into an ecology that also featured considerable clonal propagation via conidia. When keratinolytic capabilities made ecological crossover to dermatopathogenicity possible, that conventional cycle, requiring moist, deposited keratinous material, could only be maintained by pathogens infecting animals burrowing or denning in habitats with soil. Lineages adapted to animals not nesting in soil became established clonally from representatives of single mating types. They became transformed in morphology and physiology, tending to develop reduced conidiation and more exogenous growth factor requirements in addition to retaining specific host adaptations. Viewing this speciation process through the lens of population biology tools designed for interbreeding populations can give a distorted picture, since the often ecologically neutral factors considered, like spacer regions, introns, restriction sites and single nucleotide polymorphisms, likely have a slower rate of change over time than the directly adaptive factors enabling these unifactorial radiate host switching events. The current state of species concepts in the dermatophytes and related, mostly nonpathogenic dermatophytoids is reviewed in light of this contrast of perspectives. Practical steps that can be taken in the clinical laboratory to make accurate identifications based on accurate species concepts are addressed. Some species concepts are supported in lineages that have previously reduced to lower rank, such as Trichophyton indotineae, T. interdigitale, and T. soudanense. The diversity of internal transcribed spacer barcodes in T. tonsurans suggests that research into clinical differences among genotypes is warranted.

Lomentospora prolificans and Scedosporium spp. are emerging non-Aspergillus moulds causing invasive fungal disease (IFD) in onco-haematology patients. Rhino-sino-orbital and/or central nervous system (CNS) infections are poorly described yet associated with high mortality. We aimed to characterize clinical, microbiological, treatment, and outcome features of rhino-sino-orbital and/or CNS infections due to these moulds in an onco-haematology population. We retrospectively reviewed proven/probable IFD patients with rhino-sino-orbital and/or CNS involvement from 2010 to 2024 caused by L. prolificans and Scedosporium spp. at two Australian tertiary centres in adults with cancer. Eighteen episodes were analysed; 94.5% had haematological malignancy, mainly acute myeloid leukaemia (41.5%), and 53% were haematopoietic stem cell transplant recipients. Lomentospora prolificans predominated (83%) and displayed intrinsic resistance to conventional antifungals. Olorofim showed potent in vitro activity when tested (n = 5, MIC 0.125-0.5 mg/l). Disseminated disease occurred in 78%, mainly affecting lung (79%), CNS (64%), and eye (43%). Initial combination therapy with a voriconazole and terbinafine-including regimen was used in 87.5% and surgery in 50%; olorofim was administered to five patients. Overall mortality was high: 56% at 30-day and 67% at 180-day follow-up, with early death noted if there was CNS involvement (70%). Lower 30-day and 180-day mortality was observed in localized rhino-sino-orbital and Scedosporium spp. infections (0% and 20%, respectively), particularly when surgery and olorofim were used. Our results underline the high mortality from L. prolificans infections in onco-haematology patients with disseminated disease or CNS involvement. Early aggressive surgery and novel antifungals may improve outcomes, but prospective multicentre studies are needed to define optimal treatment strategies.

Reactivation of latent fungal infections poses a substantial risk for solid organ transplantation (SOT) and hematopoietic cell transplantation (HCT) recipients. We describe receipt of pretransplant fungal infection testing in an exploratory analysis among patients in a large US commercial health insurance database. We identified patients who received an SOT or HCT during January 1, 2018-January 31, 2025, and evaluated testing practices for selected fungal (blastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis) and non-fungal infections (including hepatitis B virus [HBV], hepatitis C virus [HCV], HIV, cytomegalovirus [CMV], and tuberculosis) in the year before transplantation. In total, 8.9% of 11 362 SOT and 13.0% of 6 934 HCT recipients received pretransplant fungal testing. Among SOT recipients, Coccidioides antibody was the most frequent fungal test type (5.0%), with the highest rates in states with known endemicity (e.g., Arizona: 58.7%). Among HCT recipients, cryptococcal antigen testing was the most common fungal test type (5.2%). Testing rates for viral infections and tuberculosis were substantially higher compared with fungal infection testing: HBV (SOT: 65.1%, HCT: 73.4%), HCV (SOT: 55.8%, HCT: 71.1%), HIV (SOT: 45.5%, HCT: 66.3%), CMV (SOT: 41.7%, HCT: 65.9%), and tuberculosis (SOT: 38.0%, HCT: 16.8%). Pretransplant fungal infection testing was infrequently performed compared with recommended viral and tuberculosis screening, consistent with current guidelines. Further research to understand the clinical outcomes and cost-effectiveness associated with pretransplant fungal testing could help improve approaches for targeted screening.

Mucormycosis is an opportunistic infection that affects humans and animals, being caused by moulds of the order Mucorales. In amphibians, mucormycosis has been well documented in association with Mucor amphibiorum. In this study, histopathological examination of cutaneous nodules in a Japanese common toad (Bufo japonicus) revealed fungal granulomas and sporangia. Phylogenetic analyses of five partial gene fragments, namely the internal transcribed spacer, mini chromosome maintenance complex component 7 (mcm7), largest subunit of RNA polymerase II (rpb1), 20S ribosomal RNA accumulation protein (tsr1), and cyclopropane fatty acylphospholipid synthase (cfs), obtained from the fungus isolated from lesions showed that the isolate (NBRC 117129) formed a highly supported clade with the previously known members of the Mucor circinelloides complex. Based on these morphological and molecular characteristics, we propose a new mucoralean species, Protoellisomyces batrachophilus, gen. et sp. nov.

For many decades, the fungal pathogen (Coccidioides spp.) that causes coccidioidomycosis (Valley fever) has been associated with dust exposure. However, the mechanism of atmospheric transport of arthroconidia has yet to be defined. As such, it is unclear whether the association between dust exposure and Coccidioides is coincidental or not: do soil-disturbing events simultaneously cause both free-floating Coccidioides conidia and dust particles (i.e., particulate matter) to become entrained in the atmosphere, or is Coccidioides attached to dust particles and they are jointly suspended? In this short article, we propose the dust-borne atmospheric transport hypothesis: Coccidioides conidia are transported in the atmosphere attached to dust particles, which protect the fungi from harsh environmental conditions like desiccation and UV exposure, allowing them to travel far while remaining viable in comparison to free-floating aerial transport. If true, the dust-borne atmospheric transport hypothesis provides a means for mechanistically modeling the transport and exposure risk of Coccidioides via atmospheric dispersion modeling and suggests health implications from simultaneous exposure to dust and a fungal pathogen.