Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28}  cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25}  cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

Epidemiological investigation for grouped cases of Trichosporon asahii using whole genome and IGS1 sequencing

BACKGROUND

Trichosporonosis is a rare invasive infection in humans mainly due to Trichosporon asahii, and especially recovered from patients having haematological malignancy. Since 2012, IGS1 region sequencing is used as a genotyping method to distinguish isolates, with high frequency of one haplotype worldwide and a geographic specificity for some haplotypes.

OBJECTIVES

We compared the IGS1 genotyping method and whole genome sequencing (WGS) to study the relationship between clinical isolates involved in two grouped cases in France.

METHODS

IGS1 sequencing and antifungal susceptibility testing were performed for 54 clinical isolates. Clinical data for 28 isolates included in surveillance programs were analysed. Whole genome was sequenced for 32 clinical isolates and the type strain.

RESULTS

All isolates were intrinsically resistant to flucytosine, while voriconazole had the most potent in vitro activity. The majority of the isolates was recovered from patients with haematological malignancies (42.86%), with a high proportion of children (<15 yrs-old, 32.14%) and a high mortality rate at three months (46.15%). Based on the WGS analysis, isolates exhibiting IGS1 haplotype 1, 3 and 7 belonged to different clades. Five isolates recovered during the first grouped cases had the same IGS1 haplotype and shared 99% of SNPs similarity. For the second grouped cases, four isolates had 98.7% of SNPs similarity while the isolate recovered 4 years earlier was totally unlinked.

CONCLUSIONS

We confirmed the usefulness of IGS1 sequencing for grouped cases infection of T. asahii. We underlined its limitation for the study of population structure and the utility of WGS analysis for the study of epidemiologically unrelated isolates.

Early Detection of Schistosoma Egg-Induced Pulmonary Granulomas in a Returning Traveler

We report the case of a French traveler who developed acute pulmonary schistosomiasis 2 months after visiting Benin. He presented with a 1-month history of fever, cough, and thoracic pain. Initial investigations revealed hypereosinophilia and multiple nodular lesions on chest computed tomography scan. Lung biopsies were performed 2 months later because of migrating chest infiltrates and increasing eosinophilia. Histological examination showed schistosomal egg-induced pulmonary granulomas with ova exhibiting a prominent terminal spine, resembling Schistosoma haematobium. However, egg shells were Ziehl-Neelsen positive, raising the possibility of a Schistosoma intercalatum or a Schistosoma guineensis infection. Moreover, involvement of highly infectious hybrid species cannot be excluded considering the atypical early pulmonary oviposition. This case is remarkable because of the rarity of pulmonary schistosomiasis, its peculiar clinical presentation and difficulties in making species identification. It also emphasizes the need to consider schistosomiasis diagnosis in all potentially exposed travelers with compatible symptoms.

[Onychomycoses due to molds]

Onychomycoses represent about 30% of superficial mycosis that are encountered in Dermatology consults. Fungi such as dermatophytes, which are mainly found on the feet nails, cause nearly 50% of these onychopathies. Yeasts are predominantly present on hands, whereas non-dermatophytic moulds are very seldom involved in both foot and hand nails infections. According to literature, these moulds are responsible for 2 to 17% of onychomycoses. Nevertheless, we have to differentiate between onychomycoses due to pseudodermatophytes such as Neoscytalidium (ex-Scytalidium) and Onychocola canadensis, which present a high affinity for keratin, and onychomycoses due to filamentous fungi such as Aspergillus, Fusarium, Scopulariopsis, Acremonium... These saprophytic moulds are indeed most of the time considered as colonizers rather than real pathogens agents. Mycology and histopathology laboratories play an important role. They allow to identify the species that is involved in nail infection, but also to confirm parasitism by the fungus in the infected nails. Indeed, before attributing any pathogenic role to non-dermatophytic moulds, it is essential to precisely evaluate their pathogenicity through samples and accurate mycological and/or histological analysis. The treatment of onychomycoses due to non-dermatophytic moulds is difficult, as there is today no consensus. The choice of an antifungal agent will first depend on the species that is involved in the infection, but also on the severity of nail lesions and on the patient himself. In most cases, the onychomycosis will be cured with chemical or mechanical removing of the infected tissues, followed by a local antifungal treatment. In some cases, a systemic therapy will be discussed.

Self-assembly of proteins into a three-dimensional multilayer system: investigation of the surface of the human fungal pathogen Aspergillus fumigatus

Hydrophobins are small surface active proteins that fulfil a wide spectrum of functions in fungal growth and development. The human fungal pathogen Aspergillus fumigatus expresses RodA hydrophobins that self-assemble on the outer conidial surface into tightly organized nanorods known as rodlets. AFM investigation of the conidial surface allows us to evidence that RodA hydrophobins self-assemble into rodlets through bilayers. Within bilayers, hydrophilic domains of hydrophobins point inward, thus making a hydrophilic core, while hydrophobic domains point outward. AFM measurements reveal that several rodlet bilayers are present on the conidial surface thus showing that proteins self-assemble into a complex three-dimensional multilayer system. The self-assembly of RodA hydrophobins into rodlets results from attractive interactions between stacked β-sheets, which conduct to a final linear cross-β spine structure. A Monte Carlo simulation shows that anisotropic interactions are the main driving forces leading the hydrophobins to self-assemble into parallel rodlets, which are further structured in nanodomains. Taken together, these findings allow us to propose a mechanism, which conducts RodA hydrophobins to a highly ordered rodlet structure. The mechanism of hydrophobin assembly into rodlets offers new prospects for the development of more efficient strategies leading to disruption of rodlet formation allowing a rapid detection of the fungus by the immune system.

[Rhinofacial conidiobolomycosis associated with cervical, thoracic and brachial localizations: one clinical case in Nigeria]

We report here the clinical case of a Nigerian adult patient who received medical care during October 2010, at the Center for Diagnosis and Treatment of Buruli ulcer in Pobè (Benin). He presented a massive facial tumor associated with several subcutaneous (cervical, thoracic and upper limbs) nodules, evolving since several years. Tissue samples collected at Pobè medical center were addressed to the mycology and histology laboratories of Angers University Hospital (France), according to the medical exchange agreement between the two institutions about the diagnosis and treatment of Buruli ulcer disease. Histological examination showed a Splendore-Hoeppli phenomenon, consisting of a granulomatous reaction made of eosinophilic polynuclear cells surrounding rare, large and irregular, non-septate hyphae. A filamentous fungus was isolated by cultivation of the clinical samples, which was identified as Conidiobolus coronatus. The patient was treated orally with daily doses of ketoconazole (400 mg per day). After 4 months of treatment, a marked regression of the facial lesion was obtained. A first constructive facial surgery was achieved, but the patient did not attend the second step. This case report allows us to remind the mycological diagnosis of this exotic mycosis, but also to emphasize the main difficulties encountered in medical management in the developing countries.

Unusual Aspergillus species in patients with cystic fibrosis

Poorly sporulating Aspergillus isolates from patients with cystic fibrosis (CF) are generally identified in routine procedures as Aspergillus spp. In this study, we identified and characterized 11 isolates belonging to two unusual Aspergillus species of the section Fumigati (A. lentulus and Neosartorya pseudofischeri) recovered from four different patients. Aspergillus lentulus was found occasionally during a 10-year follow-up study of one CF patient colonized by A. fumigatus. Neosartorya pseudofischeri was isolated from three patients followed in different European hospitals. This species was recovered from two sputum samples of one patient, and from four successive samples of the two other patients, suggesting that it may be responsible for chronic colonization. Both species were isolated together with A. fumigatus. Isolates from both species did not grow at 50°C, and DNA sequence analysis, together with further morphological observations permitted identification at the species level. Growth at different temperatures and antifungal susceptibility were also investigated. All the isolates of N. pseudofischeri exhibited a very low susceptibility to voriconazole (VRZ) whereas a very low susceptibility to VRZ and amphotericin B was seen with the A. lentulus isolates.

Geosmithia argillacea: an emerging pathogen in patients with cystic fibrosis

We report eight cases of airway colonization by Geosmithia argillacea in patients with cystic fibrosis. This filamentous fungus, resembling members of the genera Penicillium and Paecilomyces, was identified by molecular analysis. All patients carried a mutation on each CFTR (cystic fibrosis transmembrane conductance regulator) allele, with at least one copy of the F508del mutation. The first isolation of this fungus occurred from F508del-homozygous patients at a younger age than in F508del-heterozygous patients. Before recovery of G. argillacea, all patients were treated with itraconazole; two of them had also received voriconazole for an Aspergillus fumigatus infection. However, antifungal susceptibility patterns showed high MICs of voriconazole for all isolates, and high MICs of amphotericin B and itraconazole for the majority of them, but mostly low minimum effective concentrations (MECs) of caspofungin. The appearance and persistence of G. argillacea in the airways were not associated with exacerbation of the disease. However, the clinical implications of G. argillacea, particularly in immunocompromised patients, remain a concern, particularly given recent observations suggesting that this fungus may also cause disseminated infections.

Laser nephelometry applied in an automated microplate system to study filamentous fungus growth

By contrast with photometry (i.e., the measurement of light transmitted through a particle suspension), nephelometry is a direct method of measuring light scattered by particles in suspension. Since the scattered light intensity is directly proportional to the suspended particle concentration, nephelometry is a promising method for recording microbial growth and especially for studying filamentous fungi, which cannot be efficiently investigated through spectrophotometric assays. We describe herein for the first time a filamentous fungi–tailored procedure based on microscale liquid cultivation and automated nephelometric recording of growth, followed by extraction of relevant variables (lag time and growth rate) from the obtained growth curves. This microplate reader technique is applicable for the evaluation of antifungal activity and for large-scale phenotypic profiling.

Acremonium strictum fungaemia in a paediatric immunocompromised patient: diagnosis and treatment difficulties

During the past two decades, an increasing number of unusual moulds has been reported as responsible for septicaemia and systemic or disseminated infections in immunocompromised patients. Investigation of fever in a 10-year-old boy with acute myeloblastic leukaemia, including blood cultures on selective media, allowed the diagnosis of a fungaemia due to the slow-growing fungus Acremonium strictum. The patient recovered with liposomal amphotericin B (AmB) and voriconazole, followed by voriconazole alone due to AmB resistance. Facing a neutropenic patient with fever, clinicians usually suspect bacterial or viral aetiologies. This case, however, illustrates the need for mycological analysis of blood samples in febrile neutropenic patients and for antifungal susceptibility testing.

Development of an oligonucleotide array for direct detection of fungi in sputum samples from patients with cystic fibrosis

Cystic fibrosis (CF) is the most common inherited genetic disease in Caucasian populations. Besides bacteria, many species of fungi may colonize the respiratory tract of these patients, sometimes leading to true respiratory infections. In this study, an oligonucleotide array capable of identifying 20 fungal species was developed to directly detect fungi in the sputum samples of CF patients. Species-specific oligonucleotide probes were designed from the internal transcribed spacer (ITS) regions of the rRNA operon and immobilized on a nylon membrane. The fungal ITS regions were amplified by PCR and hybridized to the array for species identification. The array was validated by testing 182 target strains (strains which we aimed to identify) and 141 nontarget strains (135 species), and a sensitivity of 100% and a specificity of 99.2% were obtained. The validated array was then used for direct detection of fungi in 57 sputum samples from 39 CF patients, and the results were compared to those obtained by culture. For 16 sputum samples, the results obtained by the array corresponded with those obtained by culture. For 33 samples, the array detected more fungal species than culture did, while the reverse was found for eight samples. The accuracy of the array for fungal detection in sputum samples was confirmed (or partially confirmed) in some samples by cloning and resequencing the amplified ITS fragments. The present array is a useful tool for both the simultaneous detection of multiple fungal species present in the sputa of CF patients and the identification of fungi isolated from these patients.

Occurrence and relevance of filamentous fungi in respiratory secretions of patients with cystic fibrosis--a review

The colonization of airways by filamentous fungi and the development of respiratory infections require some predisposing factors as encountered in patients with cystic fibrosis (CF). Indeed, the defective mucociliary clearance which characterizes the disease is associated with local immunological disorders. In addition, the prolonged therapy with antibiotics and the use of corticosteroid treatments also facilitate fungal growth. An important fungal biota has been described in respiratory secretions of patients suffering from CF. Aspergillus fumigatus, Scedosporium apiospermum and Aspergillus terreus for filamentous fungi and Candida albicans for yeasts are the main fungal species associated with CF. Although less common, several fungal species including Aspergillus flavus and Aspergillus nidulans may be isolated transiently from CF respiratory secretions, while others such as Exophiala dermatitidis and Scedosporium prolificans may chronically colonize the airways. Moreover, some of them like Penicillium emersonii and Acrophialophora fusispora are encountered in humans almost exclusively in the context of CF. As fungal complications in CF patients are essentially caused by filamentous fungi the present review will not include works related to yeasts. In CF patients, fungi may sometimes be responsible for deterioration of lung function, as occurs in allergic broncho-pulmonary aspergillosis (ABPA) which is the most common fungal disease in this context. Additionally, although the clinical relevance of the fungal airway colonization is still a matter of debate, filamentous fungi may contribute to the local inflammatory response, and therefore to the progressive deterioration of the lung function.

Conventional methods for the diagnosis of dermatophytosis

Dermatophytes are keratinolytic fungi responsible for a large variety of diseases that can affect glabrous skin, nails and hair. In many cases, the diagnosis is not clinically obvious, and mycological analysis is required. This includes both direct microscopic examination and cultures. First of all, clinical specimens have to be sampled according to localization and characteristics of the lesions. Direct microscopic examination is usually performed using clearing reagents (KOH or Amman's chloral-lactophenol), but its sensitivity may be greatly enhanced by the use of stains or fluorochromes such as Congo red or Calcofluor white. Histological analysis is an efficient method, but it is constraining for the patients and, as direct examination, it does not allow precise identification of the pathogen. Cultures are therefore needed, and specific culture media may be used to overcome the growth of rapidly growing contaminating moulds which may hamper the recovery of dermatophytes. Identification at the species level which may be useful to initiate an appropriate treatment or for setting prophylactic measures, relies on macroscopic and microscopic morphology. Subcultures on culture media which stimulate conidiation and, for some species, the production of pigments, are often necessary. Additionally, in case of atypical isolates, some biochemical or physiological tests may be performed such as the search for urease activity or the in vitro hair perforation test. However, their contribution to species identification is rather limited, and progress is still needed for the development of biochemical or immunological tests allowing an accurate identification at the species level, pending for the availability of molecular biology-based kits.

Cutaneous Phaeohyphomycosis due to Alternaria Infectoria

Here we report a case of cutaneous alternariosis in a 74-year-old man treated by corticotherapy for myasthenia, and presenting with papular, crusted lesions on the left elbow and the right knee. Histological examination of the biopsy specimens showed fungal hyphae associated with round-shaped cells which were highly suggestive of alternariosis. Mycological culture allowed the isolation of a dematiaceous fungus which was identified as a member of the Alternaria infectoria species-group. This was confirmed by PCR amplification and sequencing of the internal transcribed spacer domain of the gene encoding nuclear ribosomal DNA and of the mitochondrial small subunit ribosomal DNA domain. The fungus was therefore referred to the Scientific Institute of Public Health where it was identified as Alternaria infectoria, on the basis of its very small 1 or 2-celled conidia often arranged in long chains and presenting with very long secondary conidiophores. Corticotherapy was stopped and a local antifungal treatment with ketoconazole was initiated, allowing the stabilisation of the cutaneous lesions within 2 months.

[Candida albicans meningo-encephalo-myelo-radiculitis at an addict]

Beside immunodepression induced by the human immunodeficiency virus, fungal infections of the central nervous system are extremely rare in heroin-addict patients. We report here a case of meningo-encephalitis with myelo-radicular lesions in a 25-year-old intravenous heroin addict but non-HIV patient, who was admitted for an acute confusion associated with gait disorders. The diagnosis of Candida albicans meningo-encephalo-myelo-radiculitis was established by magnetic resonance imagery and mycological and serological examinations of cerebrospinal fluid. The infection was cured with amphotericin B lipid complex and 5-fluorocytosine. Early diagnosis and antifungal therapy for 6 months resulted in a favorable outcome. The detection of circulating Candida mannan in cerebrospinal fluid with a more sensitive technique combined to MRI were particularly decisive to confirm Candida infection diagnosis, allowing an appropriate antifungal therapy.