Dermatophytic onychia: Effectiveness of rapid immunochromatographic diagnostic testing directly on samples compared to culture.

BACKGROUND: Until now, definite diagnosis of dermatophytic onychia has been made by taking a nail sample and placing it in culture. The result is usually obtained only after 2 to 3weeks. More recently, diagnosis within a few minutes after sampling has become possible thanks to an immunochromatography technique developed in Japan and now available in France: the Diafactory Tinea Unguium® test strip (Biosynex, France). METHODS: Over a 12-month period, 80nail samples from 80patients giving rise to a positive fungal culture were included in the study. For each patient, part of the removed nail was stored at room temperature and an immunochromatographic test was retrospectively performed according to the supplier's instructions. A small fragment of nail (≥ 1mg) was mixed with a few drops of reagent in a tube for 1min and the test strip was then placed in the tube with the result being visible to the naked eye (control strip, positivity strip) after incubation for a few minutes. RESULTS: Compared with the culture method used for 51 isolated dermatophytes (42 Trichophyton rubrum, 9 Trichophyton interdigitale), the sensitivity of the rapid test was 96.07% (49/51). For the 29other fungal cultures (10Fusarium sp., 3Scytalidium sp., 3Scopulariopsis brevicaulis,3Aspergillus sp., 1Alternaria sp., 3Candida albicans, 1Candida parapsilosis, 1Trichosporons sp., 1Rhodotorula sp., and 3Corynebacterium sp.), the specificity was 75.86% (22/29). False positives were mainly due to the genera Fusarium and Scopulariopsis (6 of 7false positives), which were the likely cause of onychomycosis. DISCUSSION: This rapid test could be useful in limiting excessive clinical diagnosis of dermatophyte onychomycosis. The rapid test has several advantages: ease of application, speed of results, and good performance, which, together, could improve diagnostic certainty during the actual consultation, thus limiting prolonged unnecessary prescriptions of antifungal treatments, while waiting for the laboratory culture results (3weeks for a negative result).

[Emergence of Candida parapsilosis candidemia at Cochin hospital. Characterization of isolates and search for risk factors]. / Émergence de candidémies à Candida parapsilosis à l'hôpital Cochin. Caractérisation des isolats et recherche de facteurs de risque.

Candida parapsilosis is a normal saprophyte of the skin, characterized by their affinity for catheters. This species has, in vitro, a level of sensitivity against the echinocandins, significantly lower than that observed with other Candida species. Recently, new species: Candida orthopsilosis and Candida metapsilosis, phenotypically identical to C. parapsilosis, have been identified by molecular biology. From 2003 to 2007, in the Cochin hospital, the proportion of C. parapsilosis among non-albicans species isolated from blood cultures increased from 17 (3/18) to 38% (5/13). To understand the reasons for this emergence, we retrospectively characterized isolates, conducted a case-control and researched a link between the emergence and introduction of caspofungin in our hospital. We analysed data from 26 patients who had candidemia with C. parapsilosis. Genotypic analysis of isolates has not identified the new species C. orthopsilosis and C. metapsilosis. The case-control study showed a broad-spectrum antibiotics was significantly more frequent for candidemia with C. parapsilosis compared to C. albicans (52 versus 26%, P=0.04) as a previous treatment with caspofungin (11 versus 0%, P=0.04). The introduction of caspofungin is contemporary with the emergence of candidemia with C. parapsilosis with a tendency to be related to its level of consumption in the ICU. Our results should encourage biologists to closely monitor the frequency and level of sensitivity of strains of C. parapsilosis isolated in hospital.

[Diagnosis of invasive pulmonary aspergillosis: value of bronchoalveolar lavage galactomannan for immunocompromised patients]. / Diagnostic de l'aspergillose bronchopulmonaire invasive: valeur du dosage du galactomannane dans le lavage bronchoalvéolaire de patients immunodéprimés.

Invasive pulmonary aspergillosis (IPA) is an emerging disease associated with high mortality. The diagnosis is difficult, based on a combination of elements that are clinical, radiological and biological. For early detection of cases of IPA, during 25 months, we have systematically carried out on the LBA (N=355) of immunocompromised patients (N=313) a determination of Aspergillus galactomannan (GM) by ELISA (PlateliaAspergillus, BioRad). We observed 14 cases of probable API. The sensitivity of GM compared to direct examination (DE) and culture is, respectively, 64% versus 29% and 57%. The determination of GM is definitely more sensitive than the ED. Excellent specificity (98%) allows its implementation as a screening test in patients at risk.

Antifungal susceptibility testing practices in mycology laboratories in France, 2018.

A survey of mycology laboratories for antifungal susceptibility testing (AFST) was undertaken in France in 2018, to better understand the difference in practices between the participating centers and to identify the difficulties they may encounter as well as eventual gaps with published standards and guidelines. The survey captured information from 45 mycology laboratories in France on how they perform AFST (number of strains tested, preferred method, technical and quality aspects, interpretation of the MIC values, reading and interpretation difficulties). Results indicated that 86% of respondents used Etest as AFST method, with a combination of one to seven antifungal agents tested. Most of the participating laboratories used similar technical parameters to perform their AFST method and a large majority used, as recommended, internal and external quality assessments. Almost all the participating mycology laboratories (98%) reported difficulties to interpret the MIC values, especially when no clinical breakpoints are available. The survey highlighted that the current AFST practices in France need homogenization, particularly for MIC reading and interpretation.

Multifocal Scedosporium apiospermum spondylitis in a cystic fibrosis patient.

We report the first case of multifocal Scedosporium apiospermum spondylitis in a cystic fibrosis patient. The infection, which occurred during voriconazole prophylaxis, disseminated contiguously from the base of the left lung and pleura and spread to vertebrae via the epidural space. S. apiospermum osteoarticular infections are rare, and are difficult to diagnose and cure because of their resistance to anti-fungal drugs.

[An update on Candida dubliniensis]. / Actualités sur Candida dubliniensis.

Eleven years ago, Irish authors, using molecular biology, demonstrated the existence of Candida dubliniensis, a new species of Candida close to Candida albicans. Initially isolated from AIDS patients with oral candidiasis, this species was detected, even in immunocompetent patients. Recently, with new, easy to implement identification tests (latex, immunochromatography), numerous epidemiological studies were undertaken. In most studies, C. dubliniensis was most often identified in the oral cavity. In the absence of HIV infection, the proportion C. dubliniensis/C. albicans ranged from 1 to 5% but it increased to 15-20% in case of HIV infection. It should be stressed that, from an experimental point of view, the acquisition of a secondary resistance to fluconazole is more quickly obtained with C. dubliniensis that with C. albicans, this resistance remains exceptionally observed in clinical observations.

[The latest data on posaconazole]. / Actualités sur le posaconazole.

Posaconazole is a lipophilic triazole antifungal agent that is structurally similar to itraconazole but has an expended spectrum of activity including yeast, molds, and dimorphic fungi. Posaconazole was licensed by the European Commission for the treatment of invasive aspergillosis, fusariosis, mycetoma, chromoblastomycosis, and coccidioidomycosis in adults who are refractory, or intolerant to other antifungal agents. Posaconazole was recently indicated for prophylaxis of invasive fungal infections in the following patients: patients receiving remission-induction chemotherapy for acute myelogenous leukemia (AML) or myelodysplastic syndromes (MDS) expected to result in prolonged neutropenia and hematopoietic stem cell transplant (HSCT) recipients who are undergoing high-dose immunosuppressive therapy for versus host disease. The spectacular activity of posaconazole against refractory infections due to zygomycetes is encouraging and suggests using posaconazole in this case. Posaconazole is only available in oral suspension formulation. Posaconazole was well tolerated in clinical trials and has lower drug interaction profile compared to other available azoles.

In vitro susceptibility testing of Candida and Aspergillus spp. to voriconazole and other antifungal agents using Etest: results of a French multicentre study.

Minimum inhibitory concentrations (MICs) of the antifungal agent voriconazole were determined using the Etest and compared with those of amphotericin B, itraconazole and fluconazole using 1986 clinical isolates of Candida spp. Voriconazole MICs were also compared with those of amphotericin B and itraconazole using 391 clinical isolates of Aspergillus spp. Voriconazole was found to have more potent activity and lower MIC values than amphotericin B, itraconazole and fluconazole against C. albicans, C. tropicalis, C. parapsilosis and C. kefyr. Against C. glabrata and C. krusei, voriconazole was more active than either of the other two azole antifungals but had similar activity to amphotericin B. For species of Aspergillus, MIC values of voriconazole were lower than those of amphotericin B and itraconazole against A. fumigatus and A. flavus, and were similar to those of amphotericin B against A. niger. Against A. terreus, MIC values for voriconazole and itraconazole were similar. A. terreus is known to be resistant to amphotericin B, and this was reflected in higher MIC values compared with those of voriconazole and itraconazole. Voriconazole therefore compares very favourably with other antifungal agents against a large number of clinical isolates of Candida and Aspergillus spp.

[Delayed testing for the diagnosis of fungi in the urines. Evaluation of the BD Vacutainer C&S tubes for the storage of urine samples at room temperature]. / Recherche différée de levures dans les urines. Evaluation des tubes BD Vacutainer C&S pour la conservation des échantillons à température ambiante.

The study included 37 urine samples which have been artificially infected with low levels (10(3) CFU/mL) of various fungi strains. We compared the effects of sample storage, up to 48 hours, at room temperature, in a urine evacuated tube containing specific additives with storage at + 4 degrees C, for the same length of time, in a urine evacuated tube without any additives. There have been no differences of results (speed of growth and colony size) between the 2 modes of storage. However, the experience has shown that samples needed a careful mixing before seeding to avoid underdetection of the strains. Based on the study results, the BD Vacutainer C&S tubes are suitable for delayed testing for the diagnosis of urine fungal infection.

Pulmonary aspergillosis.

Aspergillosis is a mycotic disease usually caused by Aspergillus fumigatus, a saprophytic and ubiquitous airborne fungus. Aspergillus-related lung diseases are traditionally classified into four different forms, whose occurrence depends on the immunologic status of the host and the existence of an underlying lung disease. Allergic broncho-pulmonary aspergillosis (ABPA) affects patients with asthma or cystic fibrosis. Saprophytic infection (aspergilloma) occurs in patients with abnormal airways (chronic obstructive pulmonary disease, bronchiectasis, cystic fibrosis) or chronic lung cavities. Chronic necrotizing aspergillosis (semi-invasive form) is described in patients with chronic lung pathology or mild immunodeficiency. Invasive aspergillosis (angio-invasive or broncho-invasive forms) occurs in severely immuno-compromised patients. Knowledge of the various radiological patterns for each form, as well as the corresponding associated immune disorders and/or underlying lung diseases, helps early recognition and accurate diagnosis.

Microscopic diagnosis of blood parasites following a cytoconcentration technique.

An isotonic fixative (formalin and thimerosal) solution, with a saponin additive to lyse erythrocytes and platelets, has been developed. The formalin and thimerosal ensure good preservation of blood parasites. This fixative has led to the development of a new concentration technique using cytocentrifugation (cytospin) in the search for Plasmodium spp., Leishmania spp., and microfilariae, as well as leukocytes in which parasites or pigment may be present. The concentration of the parasites present in the sediment from 100 microl of blood spread on a 6-mm diameter circle results in good morphology that is well stained using the usual Giemsa or Wright techniques. This new technique has the advantage of a relatively low cost and offers the possibility of isolating and identifying in the same sediment the main blood-stage parasites, with the exception of young trophozoites, of Plasmodium falciparum.

Localized oral Fusarium infection in an AIDS patient with malignant lymphoma.

We report here a case of localized oral Fusarium infection in an AIDS patient who developed an ulceration in the soft palate. Fusarium solani was identified by histopathology and culture. We believe this to be the second reported case of oral Fusarium infection in a patient with haematological malignancy and the first reported association of oral Fusarium infection with AIDS.

Anisakidosis: report of 25 cases and review of the literature.

Anisakidosis (previously known as anisakiasis) is a disease caused by the accidental ingestion of larval nematodes (Anisakis and sometimes Pseudoterranova) in raw fish. Two groups of patients are studied: 5 clinical cases and 20 serological diagnoses. 55 French cases are already published. Most of them complained of acute symptoms, which occurred within 12 h of eating the seafood meal--epigastric pain, occlusion, diffuse abdominal pain, and appendicitis. Larvae were attached to the gastric mucosa (25 cases), including an inflammatory response (erythema, oedema ulceration). Diagnosis of anisakiasis is made by gastroscopy which allows removal of the worms, and cures the patients. In gastro-intestinal tract X-rays, oedema in the mucosa, pseudo tumour formation, and filling defects (worm) were observed. In chronic infections, cases with intermittent feelings of ill health and abdominal pain, lasting from several weeks to months, were misdiagnosed as another intestinal disease. Positive serological reactions are helpful, and surgery is necessary for resection of the lesion; diagnosis is made histologically by an eosinophilic granuloma, and the presence of a larva with Y shaped lateral cords. Infestation rate is high in fishes: cod (88%), rock fish (86%), herring (88%), salmon, mackerel. Public health education should discourage the eating of raw fish. Thorough cooking to 70 degrees C or adequate freezing to -20 degrees C for 72 h are the best preventive measures. Such legislation is only in force in the Netherlands, where cases have decreased dramatically.

Clinical cure of fungal madura foot with oral itraconazole.

We report the case of a 26-year-old Malian patient who presented with mycetoma of the foot and frank bone involvement caused by Madurella mycetomatis. Long-term itraconazole therapy was clinically effective and well tolerated.

Evidence for the existence of a proteasome in Toxoplasma gondii: intracellular localization and specific peptidase activities.

The proteasome is a large intracellular protein complex whose main function is proteolytic removal of damaged proteins. It has recently been shown that the proteasome has a crucial role in the pathogenesis of protozoan parasites. We attempted to characterize the proteasome of T. gondii (RH strain). In immunoblot experiments, we showed that MCP231 monoclonal antibody, directed against the human 20S proteasome, labelled homologous proteins in T. gondii with a pattern similar to that observed in mammalian cells. The study of in vitro proteolytic activities showed that chymotrypsin-like activity (the only activity obtained with archaebacteria) was present in Toxoplasma, with Km and specific activity values close to those observed with eukaryotic cells. Immunofluorescence studies showed that the Toxoplasma proteasome predominated in the cytosol.

Detection of Toxoplasma gondii parasitemia by polymerase chain reaction in perorally infected mice.

Sequential blood samples collected from mice infected perorally with an avirulent strain of T. gondii were analysed for parasite DNA by a polymerase chain reaction method (PCR). Two pairs of primers specific for gene B1 and the repetitive DNA sequence TGR1E were used for DNA amplification. Amplified products were detected by means of electrophoresis with ethidium bromide staining. Parasitemia was also determined by cell culture. Parasitemia was never detected by the tissue culture method, whereas parasite DNA was continuously detected with PCR from day 2 to day 21. These results confirm the high sensitivity of PCR for T. gondii DNA in blood, and show that circulating DNA is present for long periods in mice following primary infection.

Trichinella murrelli: pathological features in human muscles at different delays after infection.

The authors describe the pathological aspects of muscles of three patients infected with Trichinella murrelli. Biopsies were carried out at various intervals. Six weeks after infection, the muscular larvae were not encapsulated whereas encapsulation was seen 10 weeks after infection. Six years after infection, the larvae were still alive in a nurse cell surrounded by a very thick capsule. Fourteen years after infection, cuticular larvae remnants were seen in degenerating nurse cells. The late encapsulation of Trichinella murrelli in human muscles could explain some clinical differences noticed during the outbreak during which these three patients were infected.

[Mycologic surveillance of the environment for preventive invasive aspergillosis. Proposals for standardization of the methodologies and implementation]. / Surveillance mycologique de l'environnement pour la prévention de l'aspergillose invasive. Propositions de standardisation des méthodologies et des modalités d'application.

A MAJOR RISK: The infection of immunodepressed patients by Aspergillus-type fungi increases morbidity and mortality, particularly in hematology units or during solid organ transplantation. Although present diagnostic means benefit from the progress over the last years, they remain limited and chemoprophylaxis protocols have still not demonstrated significant efficacy. THE NEED FOR RECOMMENDATIONS: Today, the handling of environmental risks is the only strategy that has proved its efficacy and usefulness. On the basis of administrative recommendations and data from the literature, a multicentric and pluri-disciplinary task force, grouping clinicians, microbiologists and hygienists, has assessed different methods and has proposed recommendations for the standardization and optimization of fungal surveillance of the environment.

[Detection of trypanosomes in blood by the Quantitative Buffy Coat (QBC) technique: experimental evaluation]. / Détection des trypanosomes dans le sang par la technique du Quantitative Buffy Coat (QBC): évaluation expérimentale.

Microhematocrit centrifugation (Woo test) and miniature anion exchange are the most widely used techniques for routine detection of Trypanosoma brucei gambiense in endemic areas. The QBC technique developed for diagnosis of malaria has been successfully used for detection of trypanosoma in blood. The purpose of this laboratory study was to evaluate the end-point sensitivity of the QBC test in comparison with the Woo test. Decreasing concentrations from 15 x 10(5) to 15 trypanosomes/ml of human blood were tested using the two techniques. Sensitivity was calculated in function of reading time at each concentration. Results showed that the sensitivity of the QBC test was 95% down to a concentration of 450 trypanosomes/ml. In comparison 95% sensitivity of the Woo test was observed only down to 7500 trypanosomes/ml and reading time was twofold longer. These findings were reproducible for two hours after sample preparation but deterioration was rapid thereafter. Given its simplicity and sensitivity, QBC test would appear to be a suitable technique for in-field screening programs for human African trypanosomiasis.

Late occurrence of Histoplasma duboisii cutaneous and pulmonary infection 18 years after exposure.

We report an imported case of Histoplasma capsulatum var. duboisii (H. duboisii) infection in a white French woman revealed by cutaneous lesions of the scalp, 18 years after her last stay in West and Central Africa. Asymptomatic bilateral pulmonary infiltrates were discovered on thoracic computed tomography. Skin biopsy allowed the positive diagnosis showing the typical yeasts; culture of biopsy specimens was positive for H. capsulatum. In the absence of criteria of severity, the patient was treated for one year with oral itraconazole 400mg/day. The outcome was favourable, skin and pulmonary lesions resolved slowly. The follow up is 5 years without relapse after the end of treatment. This case illustrates the possibility of late occurrence of H. duboisii infection, many years after exposure and the major importance of asking any patient for travelling or residency in tropical countries.