Scedosporium Species Research Articles

A Stress Hub in Scedosporium apiospermum: The High Osmolarity Glycerol (HOG) Pathway

Scedosporium species are opportunistic filamentous fungi found in human-impacted areas. Clinically relevant species, such as S. apiospermum, rank as the second most frequent colonizers of the airways of patients with cystic fibrosis (CF), which are characterized by persistent oxidative stress. This raises the question of how Scedosporium species abate conditions imposed in hostile environments. Since the High Osmolarity Glycerol (HOG) pathway plays a central role in fungal adaptation to stress, we aimed to pheno-profile the involvement of the pathway in response to stress in S. apiospermum using Western blot. We show for the first time that a wide range of stress distinctively activates the HOG pathway in S. apiospermum, including oxidants (H2O2, menadione, cumene hydroperoxide, diamide, paraquat, and honokiol), osmotic agents (sorbitol and KCl), cell-wall stress agents (caffeine, calcofluor white, and Congo Red), heavy metals (cadmium and arsenite), fungicides (fludioxonil and iprodione), antifungals (voriconazole and amphotericin B), and acid stress (pH 4). We suggest that the function of the HOG pathway as a general stress regulator is also conserved in S. apiospermum.

60-Year-Old Patient with Invasive Mold Infection Consequent to an Encounter with a Barnyard Animal

Abstract Introduction/Objective Lichtheimia and Scedosporium species are ubiquitous fungi associated with a range of clinical presentations. We report a complex soft tissue coinfection caused by Lichtheimia spp. and Scedosporium spp. following a puncture wound by a rooster spur. Methods/Case Report A 60-year-old immunosuppressed man with a history of heart transplant presented with a non-healing wound 2-months after sustaining a lower leg puncture secondary to a rooster spur. The patient was previously treated with Augmentin for presumed cellulitis without improvement. To characterize the ongoing disease process, the wound was sampled with tissue portions routed for both histopathologic review and culture. In short order, the biopsy demonstrated invasive hyaline pauciseptate fungal hyphae consistent with organisms of the Mucorales order. In congruence, culture rapidly revealed a mucoraceous mold, subsequently identified as a Lichtheimia spp. Thus, the patient was treated with liposomal amphotericin B. However, days later, a second fungus - a Scedosporium spp. - was isolated from the original specimen. Consequently, isavuconazonium sulfate therapy was added. Re-review of the initial biopsy enabled distinction of two populations of fungal hyphae plausibly representing both molds. Despite numerous debridements and optimal medical management, the patient was ultimately referred for amputation. Results (if a Case Study enter NA) NA. Conclusion When encountered in an immunocompromised host, providers understandably respond to an invasive mucoraceous mold with alarm followed by quick, decisive action. However, septate molds, such as the Scedosporium spp., can also be aggressive. Further, the presence of more than one invasive mold presents a treatment challenge as the mucormycetes may require surgery coupled with amphotericin B therapy; whereas, the a Scedosporium spp. may be wholly resistant to amphotericin B. This case illustrates the critical role that an alert pathologist plays in guiding management through integration of data from different diagnostic modalities. It also constitutes an emphatic reminder that an illness may be caused by more than one actionable, invasive fungus.

Extracellularly Released Molecules by the Multidrug-Resistant Fungal Pathogens Belonging to the Scedosporium Genus: An Overview Focused on Their Ecological Significance and Pathogenic Relevance.

The multidrug-resistant species belonging to the Scedosporium genus are well recognized as saprophytic filamentous fungi found mainly in human impacted areas and that emerged as human pathogens in both immunocompetent and immunocompromised individuals. It is well recognized that some fungi are ubiquitous organisms that produce an enormous amount of extracellular molecules, including enzymes and secondary metabolites, as part of their basic physiology in order to satisfy their several biological processes. In this context, the molecules secreted by Scedosporium species are key weapons for successful colonization, nutrition and maintenance in both host and environmental sites. These biologically active released molecules have central relevance on fungal survival when colonizing ecological places contaminated with hydrocarbons, as well as during human infection, particularly contributing to the invasion/evasion of host cells and tissues, besides escaping from the cellular and humoral host immune responses. Based on these relevant premises, the present review compiled the published data reporting the main secreted molecules by Scedosporium species, which operate important physiopathological events associated with pathogenesis, diagnosis, antimicrobial activity and bioremediation of polluted environments.

P165 Mycological profile of keratitis from tertiary care center in the state of Chattisgarh, India

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM ObjectiveTo assess the burden of fungal etiology of clinically suspected mycotic keratitis amongst the patient presented to the Ophthalmology department in a tertiary care hospital in Chhattisgarh.MethodsThis is a laboratory-based retrospective study of the corneal scrapings received for mycological processing between January 2020-December 2021. Demographic data were collected from patients and from their medical records. Corneal scrapings were aseptically collected from the margins of the ulcer using a sterile Kimura blade in the Ophthalmology department and the samples were processed by following the standard microbiology protocol. A wet mount examination with 10% KOH was done. Samples were also smeared onto a sterile slide for Gram stain. Samples were inoculated in a C-shaped manner on media on blood agar, chocolate agar, and Sabouraud's dextrose agar supplemented with chloramphenicol. Media were incubated in a 25°C aerobic incubator and observed for growth daily for a week and thereafter on alternate days. Blood agar was incubated at 37°C. Fungi were identified by the conventional method by Lactophenol cotton blue microscopy (LPCB) and slide culture. Antifungal susceptibility testing for Voriconazole with E-test was performed for Aspergillus and Fusarium species.ResultsA total of 37 patients with suspected mycotic keratitis were included in the duration of the study period. The demographic details hinted more predisposition of keratitis in females than in males; with a mean age of 49 ± 2 years and a range from 21 to 80 years. The predominant predisposing factor was trauma with organic matter in agricultural background. Amongst the total 37.8% (14/37) were positive for both KOH and culture, while 5.4% (2/37) were KOH negative but culture positive. There were 5 isolates that could hint toward low sample load or certain technical logistic issues could not be culture. Amongst culture-positive isolates, Fusarium species (37.5%) was the most common isolate showing predominance of Fusarium oxysporum, followed by Acremonium species and Aspergillus species 19%, with rare isolation of Colletotrichum dematium and Scedosporium species.ConclusionCulture remained the gold standard for the detection of fungal agents which will help to know the epidemiology of the local areas and guide the clinicians to prevent and treat the affected patients effectively. The tropical environment and agricultural occupation in Chhattisgarh present variability in the etiology of mycotic keratitis. With the predominance of Fusarium species, unusual fungal isolates of C. dematium and Scedosporium species from corneal ulcers were observed. Early detection is essential to initiate appropriate antifungal therapy and to minimize preventable ocular complications like blindness.

S10.5a Fungal respiratory infections in cystic fibrosis patients in the Middle East

S10.5 Fungal respiratory infections in Cystic Fibrosis, September 24, 2022, 10:30 AM - 12:00 PMCystic Fibrosis (CF) is among the most common genetic disorders, which involves multiple organs including the respiratory tract. CF is thought to be an uncommon disease in the Middle East (ME). However, the prevalence is estimated at 1 in 30 000-50 000, while the incidence is estimated at 1 in 2000-5800 live births. Several studies from ME revealed that many children with CF in these populations probably remain undiagnosed due to lack of clinical suspicion and proper diagnostic facilities. According to the experts’ idea, CF may be more common in Iran than expected before. Chronic colonization of the airways of CF patients and infections due to a wide variety of opportunistic fungal pathogens including Aspergillus, Candida, Scedosporium species, Exophiala dermatitidis, Rasamsonia argillacea complex, and Lomentospora prolificans are currently increasing. On the other hand, the resistance of these opportunistic pathogens to commonly available antifungals challenges therapeutic options and consequently endanger the CF patients’ life. Dissimilar to bacterial colonization or infections, the epidemiology and pathogenicity of colonization and fungal respiratory infections in CF are less known. According to our recent study, the prevalence rate of respiratory colonization was reported as 73.3%. Among mold isolates, Aspergillus was also the most common genus followed by Scedosporium species. In contrast to the reports from western countries, A. flavus was also identified as the most prevalent species of Aspergillus from ME countries including Iran and India. In some studies, allergic bronchopulmonary aspergillosis (ABPA) in CF patients from ME was evaluated. In our recent experience from Iran, of 86 patients with CF, 9 (10.5%) cases were met ABPA diagnosis. A. flavus was the most common agent followed by A. fumigatus, A. terreus and A. tubingensis. A significant resistance of Scedosporium and Aspergillus isolates from CF patients against the main antifungal agents in invasive fungal infections therapy was reported in different studies. According to these realities, there are a few reports on the Research Topic ‘Fungal Respiratory Infections and Colonization in CF’ from Iran and some other ME countries. Therefore, in this presentation, we are going to highlight our experiences and other published data from Iran and ME in this field including clinical presentations, fungal species involved, diagnosis strategies, and in vitro antifungal susceptibility patterns of fungal isolates from CF patients, and common treatments and prophylactic strategies.

Genotypic diversity and antifungal susceptibility of Scedosporium species from clinical settings in China.

Scedosporium species have drawn significant interest as inhabitants of polluted soil and water and as cause of high mortality in near-drowning patients. So far, most cases have been reported from Europe and Australia, while knowledge on their prevalence and genotypic diversity from Asia is scant. To increase the knowledge of the genetic diversity and in vitro antifungal susceptibility of Scedosporium species involved in human infections from China. Here, we applied the ISHAM-MLST consensus scheme for molecular typing of Scedosporium species and revealed both high species diversity and high genotypic diversity among 45 Chinese clinical Scedosporium isolates. Among the five species, Scedosporium boydii (n=22) was the most common, followed by S. apiospermum (n=18), S. aurantiacum (n=4) and S. dehoogii (n=1). S. aurantiacum was reported for the first time from clinical samples in China. The predominant sequence types (STs) were ST17 in S. apiospermum, ST4 in S. boydii and ST92 in S. aurantiacum, including four novel STs (ST40, ST41, ST42 and ST43) in S. apiospermum. Based on the CLSI-M38 A2 criterion, voriconazole was the only antifungal compound with low MIC values (MIC90 ≤ 1μg/ml) for all Scedosporium isolates in our study. The genetic diversity of clinical isolates of Scedosporium species from China is extremely high, with S. boydii being predominant and S. aurantiacum being firstly reported here. VOR was the only antifungal compound with low MIC values for all Scedosporium isolates in our study, which should be recommended as the firstline antifungal treatment against scedosporiosis in China.

EUCAST-Obtained Olorofim MICs against Aspergillus and Scedosporium Species and Lomentospora prolificans Showed High Agreements between Visual Inspection and Spectrophotometric Readings.

Previous studies show high agreement between MIC spectrophotometric readings and visual inspection of azoles and amphotericin B against Aspergillus fumigatus isolates. Here, we tested and compared the in vitro activity of a novel antifungal, olorofim, against Aspergillus spp., Scedosporium spp., and Lomentospora prolificans by visual inspection and spectrophotometric readings. Clinical isolates of Aspergillus (n = 686) and Scedosporium (n = 36) spp. and L. prolificans (n = 13) were tested. Olorofim MICs were evaluated-following the EUCAST E.Def 9.4 procedure-by visual inspection or spectrophotometric readings (combinations of either ≥90% or ≥95% fungal growth inhibition endpoints compared to drug-free control endpoints and different wavelengths [405 nm, 450 nm, 492 nm, 540 nm, and 620 nm]). We observed high in vitro activity of olorofim against all tested Aspergillus spp. (MICs up to 0.06 mg/L), except for A. calidoustus, and against L. prolificans and Scedosporium spp. (MICs up to 0.125 mg/L). The combination of ≥90% fungal growth inhibition endpoints at wavelengths of ≥492 nm resulted in high essential agreements with A. fumigatus and lesser agreement with non-fumigatus Aspergillus, Scedosporium spp., and L. prolificans, although the number of isolates studied was low. This single-center study shows high agreement among olorofim MICs against A. fumigatus by visual inspection and spectrophotometric readings (≥90% fungal growth inhibition endpoints and wavelengths of ≥492 nm) and encouraging results against non-fumigatus Aspergillus spp., Scedosporium spp., and L. prolificans.

Novel α-Aminophosphonates and α-Aminophosphonic Acids: Synthesis, Molecular Docking and Evaluation of Antifungal Activity against Scedosporium Species.

The Scedosporium genus is an emerging pathogen with worldwide prevalence and high mortality rates that gives multidrug resistance to antifungals; therefore, pharmacological alternatives must be sought for the treatment of diseases caused by this fungus. In the present project, six new α-aminophosphates were synthesized by the Kabachnik–Fields multicomponent reaction by vortex agitation, and six new monohydrolyzed α-aminophosphonic acids were synthesized by an alkaline hydrolysis reaction. Antifungal activity was evaluated using the agar diffusion method as an initial screening to determine the most active compound compared to voriconazole; then it was evaluated against 23 strains of the genus Scedosporium following the M38-A2 protocol from CLSI (activity range: 648.76–700 µg/mL). Results showed that compound 5f exhibited the highest antifungal activity according to the agar diffusion method (≤1 mg/mL). Cytotoxicity against healthy COS-7 cells was also evaluated by the MTT assay and it was shown that compound 5f exhibits a lower toxicity in comparison to voriconazole at the same concentration (1000 µM). A docking study was conducted afterwards, showing that the possible mechanism of action of the compound is through the inhibition of allosteric 14-α-demethylase. Taking these results as a basis, 5f is presented as a compound with attractive properties for further studies.

In depth search of the Sequence Read Archive database reveals global distribution of the emerging pathogenic fungus Scedosporium aurantiacum.

Scedosporium species are emerging opportunistic fungal pathogens causing various infections mainly in immunocompromised patients, but also in immunocompetent individuals, following traumatic injuries. Clinical manifestations range from local infections, such as subcutaneous mycetoma or bone and joint infections, to pulmonary colonization and severe disseminated diseases. They are commonly found in soil and other environmental sources. To date S. aurantiacum has been reported only from a handful of countries. To identify the worldwide distribution of this species we screened publicly available sequencing data from fungal metabarcoding studies in the Sequence Read Archive (SRA) of The National Centre for Biotechnology Information (NCBI) by multiple BLAST searches. S. aurantiacum was found in 26 countries and two islands, throughout every climatic region. This distribution is like that of other Scedosporium species. Several new environmental sources of S. aurantiacum including human and bovine milk, chicken and canine gut, freshwater, and feces of the giant white-tailed rat (Uromys caudimaculatus) were identified. This study demonstrated that raw sequence data stored in the SRA database can be repurposed using a big data analysis approach to answer biological questions of interest.Lay summaryTo understand the distribution and natural habitat of S. aurantiacum, species-specific DNA sequences were searched in the SRA database. Our large-scale data analysis illustrates that S. aurantiacum is more widely distributed than previously thought and new environmental sources were identified.

Performance of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Scedosporium, Acremonium-Like, Scopulariopsis, and Microascus Species.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a powerful microorganism identification tool. Research on MALDI-TOF MS identification of rare filamentous fungi is still lacking. This study aimed to evaluate the performance of MALDI-TOF MS in the identification of Scedosporium, Acremonium-like, Scopulariopsis, and Microascus species. Sabouraud broth cultivation and formic acid/acetonitrile protein extraction were used for MALDI-TOF MS identification by a Bruker Biotyper system. An in-house database containing 29 isolates of Scedosporium, Acremonium-like, Scopulariopsis, and Microascus spp. was constructed. A total of 52 clinical isolates were identified using the Bruker Filamentous Fungi Library v1.0 (FFL v1.0) alone, and Filamentous Fungi Library v1.0 plus the in-house library, respectively. The mass spectrum profile (MSP) dendrograms of the 28 Scedosporium isolates, 26 Acremonium-like isolates, and 27 Scopulariopsis and Microascus isolates were constructed by MALDI Biotyper OC 4.0 software, respectively. The correct species identification rate significantly improved when using the combined databases compared with that when using FFL v1.0 alone (Scedosporium spp., 75% versus 0%; Acremonium-like spp., 100% versus 0%; Scopulariopsis and Microascus spp., 100% versus 62.5%). The MSP dendrograms differentiated Acremonium-like species, Scopulariopsis and Microascus species clearly, but cannot distinguish species in the Scedosporium apiospermum complex. In conclusion, with an expanded database, MALDI-TOF MS is an effective tool for the identification of Scedosporium, Acremonium-like, Scopulariopsis, and Microascus species.

The synergistic effect of minocycline and azole antifungal drugs against Scedosporium and Lomentospora species

BackgroundThis study was aimed to determine the potency of Minocycline (MIN) and azoles, including itraconazole (ITR), voriconazole (VOR) and posaconazole (POS) against Scedosporium and Lomentospora species.ResultsThis study revealed that MIN exhibited no significant antifungal activity against any of the tested strains, whereas in vitro combination of MIN with ITR, VOR or POS showed satisfactory synergistic effects against 8 (80%), 1 (10%), and 9 (90%) strains, respectively. Moreover, combined use of MIN with azoles decreased the minimum inhibitory concentration (MIC) range from 5.33–16 μg/ml to 1–16 μg/ml for ITR, from 0.42–16 μg/ml to 0.21–16 μg/ml for VOR, and from 1.33–16 μg/ml to 0.33–16 μg/ml for POS. Meanwhile, no antagonistic interactions were observed between the above combinations. The G. mellonella infection model demonstrated the in vivo synergistic antifungal effect of MIN and azoles.ConclusionsThe present study demonstrated that combinations between MIN and azoles lead to synergistic antimicrobial effects on Scedosporium and Lomentospora species, while showing a potential for overcoming and preventing azole resistance.

Clinical features, diagnosis and treatment outcome of fungal endocarditis: A systematic review of reported cases.

The landscape of fungal endocarditis (FE) has constantly been evolving in the last few decades. Despite the advancement in diagnostic methods and the introduction of newer antifungals, mortality remains high in FE. This systematic review aimed to evaluate the epidemiology, clinical features, diagnostic and therapeutic interventions in patients with FE. We also aim to examine the aforementioned factors as a determinant of mortality in FE. A literature search was performed in PubMed, Google Scholar and Scopus, and all patients ≥18years with proven fungal endocarditis were included. A total of 220 articles (250 patients) were included in the final analysis. Candida was the commonest aetiology (49.6%), followed by Aspergillus (30%) and Scedosporium species (3.2%). The proportion of prosthetic valve endocarditis (PVE) and intravenous drug users was 35.2% and 16%, respectively. The overall mortality rate was 40%. On multivariate analysis, Aspergillus endocarditis (HR 3.7, 95% CI 1.4-9.7; p = .009) and immunocompromised state (HR 2.8, 95% CI 1.24-6.3; p = .013) were independently associated with mortality. Patients treated with surgery along antifungals had better survival (HR 0.20, 95% CI 0.09-0.42; p<.001) compared to those treated with antifungals alone. Recurrence of FE was reported in 10.4% of patients. In conclusion, FE carries significant mortality, particularly in immunodeficient and Aspergillus endocarditis. We advocate the use of surgery combined with antifungals to improve clinical outcomes.

Consensus guidelines for the diagnosis and management of invasive fungal disease due to moulds other than Aspergillus in the haematology/oncology setting, 2021.

Invasive fungal disease (IFD) due to moulds other than Aspergillus is a significant cause of mortality in patients with malignancies or post haemopoietic stem cell transplantation. The current guidelines focus on the diagnosis and management of the common non-Aspergillus moulds (NAM), such as Mucorales, Scedosporium species (spp.), Lomentospora prolificans and Fusarium spp. Rare but emerging NAM including Paecilomyces variotii, Purpureocillium lilacinum and Scopulariopsis spp. are also reviewed. Culture and histological examination of tissue biopsy specimens remain the mainstay of diagnosis, but molecular methods are increasingly being used. As NAM frequently disseminate, blood cultures and skin examination with biopsy of any suspicious lesions are critically important. Treatment requires a multidisciplinary approach with surgical debridement as a central component. Other management strategies include control of the underlying disease/predisposing factors, augmentation of the host response and the reduction of immunosuppression. Carefully selected antifungal therapy, guided by susceptibility testing, is critical to cure. We also outline novel antifungal agents still in clinical trial which offer substantial potential for improved outcomes in the future. Paediatric recommendations follow those of adults. Ongoing epidemiological research, improvement in diagnostics and the development of new antifungal agents will continue to improve the poor outcomes that have been traditionally associated with IFD due to NAM.

The use of combined PCR, fluorescence in situ hybridisation and immunohistochemical staining to diagnose mucormycosis from formalin-fixed paraffin-embedded tissues.

To develop a comprehensive diagnostic system for mucormycosis from formalin-fixed paraffin-embedded tissues, consisting of own-designed real-time polymerase chain reaction (PCR) assays, fluorescence in situ hybridisation, and immunohistochemical staining. We designed 11 primers and probes for specific real-time PCR assays based on genome sequences, and validated the specificity by Aspergillus, Fusarium, Scedosporium, Lomentospora, Cryptococcus and Candida species. Formalin-fixed paraffin-embedded (FFPE) tissues from forty-four mouse model infected by above fungi were collected and extracted DNA by laser capture microdissection (LCM) and direct extraction methods for real-time PCR assays. In addition, seventeen clinical specimens histopathologically proven for mucormycosis were included for specific detection with the new diagnostic system. The real-time PCR assays allowed detection of a minimum of 10CFU/ml equivalent gDNA of each species. No cross-reaction with gDNA among species was noted. From mouse model specimens, the sensitivity of real-time PCR in samples extracted with LCM versus direct extraction method was 100% versus 91.43% at Mucorales level and 80% versus 45.71% at species level, respectively. The specificity was 100%. From clinical samples, LCM combined with real-time PCR can test 88.24% (15/17) of Mucorales. Sensitivities of fluorescence in situ hybridisation (FISH) and immunohistochemical staining (IHC) were 70.59% and 41.18%, respectively. Combined LCM-RT-PCR, FISH and IHC yielded positive results in all samples. The combination diagnostic system we developed is a culture-independent and robust method which enables rapid species identification from FFPE tissues for timely diagnosis of mucormycosis.

Identification of Promising Antifungal Drugs against Scedosporium and Lomentospora Species after Screening of Pathogen Box Library.

Fungal infections have been increasing during the last decades. Scedosporium and Lomentospora species are filamentous fungi most associated to those infections, especially in immunocompromised patients. Considering the limited options of treatment and the emergence of resistant isolates, an increasing concern motivates the development of new therapeutic alternatives. In this context, the present study screened the Pathogen Box library to identify compounds with antifungal activity against Scedosporium and Lomentospora. Using antifungal susceptibility tests, biofilm analysis, scanning electron microscopy (SEM), and synergism assay, auranofin and iodoquinol were found to present promising repurposing applications. Both compounds were active against different Scedosporium and Lomentospora, including planktonic cells and biofilm. SEM revealed morphological alterations and synergism analysis showed that both drugs present positive interactions with voriconazole, fluconazole, and caspofungin. These data suggest that auranofin and iodoquinol are promising compounds to be studied as repurposing approaches against scedosporiosis and lomentosporiosis.

Prevalence of Scedosporium keratitis in a rural tertiary care hospital

Aim: To study the prevalence of Scedosporium in fungal keratitis infection from a rural tertiary care hospital. Method: Corneal scraping samples from October 2018 to October 2019 had come to Microbiology central laboratory at Narayana nethralaya hospital,Bommasandra Bangalore. 94 samples were collected using a surgical scalpel blade no. 15 and it was subjected to microscopic Gram stain examination and 10%Pottasium hydroxide (KOH) mount and culture techniques. 16 samples on Sabouraud dextrose agar (SDA) started growing after 72 h and these were initially floccose, with a white hairy growth with greyish surface and yellow reverse. No growth was seen on blood agar and chocolate agar after 1 week of incubation. Lacto phenol cotton blue (LPCB) staining was performed after seven days of incubation by tease mount method and observed by binocular compound microscope with low power x10 and high power ×45, which shows septate hyphae, ovoid conidia with truncated bases suggestive of Scedosporium species. Results: 16 samples on Sabouraud dextrose agar (SDA) started growing after 72 h and these were initially floccose, with a white hairy growth with greyish surface and yellow reverse, suggestive of Scedosporium species.10 samples showed white, floccose, cottony myceleal growth on SDA and LPCB mount shows slightly curved micro and macro conidia accumulating around tips of phialides, suggestive of fusarium species. 10 samples revealed phaeoid, brown fungus with hairy growth on SDA and LPCB mount showed septate, slightly tapering curved conidia suggestive of Curvularia species. Conclusion: majority of Scedosporium growth was observed in our study(44%), compared to Fusarium(27%) and Curvularia(27%) species. In our retrospective study we found that males(35%) are more infected with fungal keratitis than females(8.3%), age group 50 to 60 years were affected more with Scedosporium keratitis infection.

Prevalence of Scedosporium keratitis in a rural tertiary care hospital

Aim: To study the prevalence of Scedosporium in fungal keratitis infection from a rural tertiary care hospital. Method: Corneal scraping samples from October 2018 to October 2019 had come to Microbiology central laboratory at Narayana nethralaya hospital,Bommasandra Bangalore. 94 samples were collected using a surgical scalpel blade no. 15 and it was subjected to microscopic Gram stain examination and 10%Pottasium hydroxide (KOH) mount and culture techniques. 16 samples on Sabouraud dextrose agar (SDA) started growing after 72 h and these were initially floccose, with a white hairy growth with greyish surface and yellow reverse. No growth was seen on blood agar and chocolate agar after 1 week of incubation. Lacto phenol cotton blue (LPCB) staining was performed after seven days of incubation by tease mount method and observed by binocular compound microscope with low power x10 and high power ×45, which shows septate hyphae, ovoid conidia with truncated bases suggestive of Scedosporium species. Results: 16 samples on Sabouraud dextrose agar (SDA) started growing after 72 h and these were initially floccose, with a white hairy growth with greyish surface and yellow reverse, suggestive of Scedosporium species.10 samples showed white, floccose, cottony myceleal growth on SDA and LPCB mount shows slightly curved micro and macro conidia accumulating around tips of phialides, suggestive of fusarium species. 10 samples revealed phaeoid, brown fungus with hairy growth on SDA and LPCB mount showed septate, slightly tapering curved conidia suggestive of Curvularia species. Conclusion: majority of Scedosporium growth was observed in our study(44%), compared to Fusarium(27%) and Curvularia(27%) species. In our retrospective study we found that males(35%) are more infected with fungal keratitis than females(8.3%), age group 50 to 60 years were affected more with Scedosporium keratitis infection.

Miltefosine Against Scedosporium and Lomentospora Species: Antifungal Activity and Its Effects on Fungal Cells.

Scedosporium and Lomentospora species are filamentous fungi responsible for a wide range of infections in humans and are frequently associated with cystic fibrosis and immunocompromising conditions. Because they are usually resistant to many antifungal drugs available in clinical settings, studies of alternative targets in fungal cells and therapeutic approaches are necessary. In the present work, we evaluated the in vitro antifungal activity of miltefosine against Scedosporium and Lomentospora species and how this phospholipid analogue affects the fungal cell. Miltefosine inhibited different Scedosporium and Lomentospora species at 2–4 µg/ml and reduced biofilm formation. The loss of membrane integrity in Scedosporium aurantiacum caused by miltefosine was demonstrated by leakage of intracellular components and lipid raft disorganisation. The exogenous addition of glucosylceramide decreased the inhibitory activity of miltefosine. Reactive oxygen species production and mitochondrial activity were also affected by miltefosine, as well as the susceptibility to fluconazole, caspofungin and myoricin. The data obtained in the present study contribute to clarify the dynamics of the interaction between miltefosine and Scedosporium and Lomentospora cells, highlighting its potential use as new antifungal drug in the future.

Answer to August 2021 Photo Quiz.

Spherical brown cleistothecia (100 to 300 μm in diameter) of Scedosporium containing oblong brown ascospores were observed in Fig. 1B and C. Cleistothecia are the hallmark of the sexual stage (teleomorph) of this filamentous fungus, which belongs to the phylum Ascomycota. The teleomorph is also known under the genus name Pseudallescheria (1). Strains isolated from clinical samples rarely produce these sexual reproductive structures, but they can be obtained from culture, particularly on nutrient-poor media such as cornmeal agar or potato dextrose agar, after 2 to 3 weeks of growth (1). The development of cleistothecia in the sinus cavity could be correlated with a less favorable environment for fungus growth. The hyphae of this mold are hyaline, and the brownish black color of the colony is due to the brown color of conidia and not to melanin production (2); hence, the Fontana-Masson staining should be considered negative (1). Microscopy does not distinguish between Scedosporium species. Pseudallescheria ellipsoidea was identified by sequencing a partial region of the beta-tubulin gene (GenBank accession number MT821950; 97.86% match with the type strain P. ellipsoidea CBS 418.73 [KT008449]) (see Fig. S1 in the supplemental material) (3). This species belongs to the Scedosporium apiospermum species complex, which also comprises Pseudallescheria angusta, S. apiospermum, Scedosporium boydii, and Pseudallescheria fusoidea.

The Glycosylphosphatidylinositol-Anchored Superoxide Dismutase of Scedosporium apiospermum Protects the Conidia from Oxidative Stress.

Scedosporium species are common fungal pathogens in patients with cystic fibrosis (CF). To colonize the CF lungs, fungi must cope with the host immune response, especially the reactive oxygen species (ROS) released by phagocytic cells. To this aim, pathogens have developed various antioxidant systems, including superoxide dismutases (SODs) which constitute the first-line protection against oxidative stress. Interestingly, one of the S. apiospermum SOD-encoding genes (SODD gene) exhibits a glycosylphosphatidylinositol (GPI) anchor-binding site and encodes a conidial-specific surface SOD. In this study, a SODDΔ mutant was engineered from a non-homologous end joining-deficient strain (KU70Δ) of S. apiospermum. Compared to its parent strain, the double mutant KU70Δ/SODDΔ exhibited increased susceptibility to various oxidizing agents and triazole antifungals. In addition, the loss of SodD resulted in an increased intracellular killing of the conidia by M1 macrophages derived from human blood monocytes, suggesting the involvement of this superoxide dismutase in the evasion to the host defenses. Nevertheless, one cannot disregard an indirect role of the enzyme in the synthesis or assembly of the cell wall components since transmission electron microscopic analysis revealed a thickening of the inner cell wall layer of the conidia. Further studies are needed to confirm the role of this enzyme in the pathogenesis of Scedosporium infections, including the production of a recombinant protein and study of its protective effect against the infection in a mouse model of scedosporiosis.