[Prevalence of Candida parapsilosis, C. orthopsilosis and C. metapsilosis in candidemia over a 5-year period at Nantes hospital and in vitro susceptibility to three echinocandins by E-test®]. / Prévalence de Candida parapsilosis, C. orthopsilosis et de C. metapsilosis au sein des candidémies au CHU de Nantes et profil de sensibilité aux échinocandines par la méthode E-test®: étude rétrospective de cinq ans (2004-2009).

AIM OF THE STUDY: To determine the prevalence of C. parapsilosis sensu stricto, C. orthopsilosis and C. metapsilosis among candidemia at Nantes University Hospital and to evaluate the in vitro susceptibility of the isolates against three echinocandin drugs (caspofungin, micafungin and anidulafungin). MATERIAL AND METHODS: Retrospective study (march 2004 to july 2009) of 178 cases of candidemia corresponding to 183 Candida spp. strains identified by means of routine phenotypical methods. Re-identification of C. parapsilosis sensu lato isolates was performed by ITS rDNA sequencing analysis. Minimal inhibitory concentrations (MIC) were determined by E-test(®). All echinocandin non-susceptible isolates (MIC>2 µg/mL) were analyzed for the presence/absence of FKS1 mutations associated with resistance. RESULTS: During this period, C. parapsilosis sensu lato was responsible for 27 candidemia, ranging at the second most common Candida species after C. albicans (n=99, 54.1%). Neither isolates belong to C. orthopsilosis nor C. metapsilosis. According to the literature, all the isolates displayed high MICs against the three echinocandin drugs. All the isolates displayed both susceptibility (MIC ≤ 2 µg/mL) and a good agreement between MICs read at 24h and 48 h for caspofungin and micafungin (MIC(50)=0.75 µg/mL, MIC(90)=1.5 µg/mL). Surprisingly, whereas most of the strains were susceptible to anidulafungin at 24h (MIC(50)=1 µg/mL, MIC(90)=1.5 µg/mL), 14 (52 %) displayed non-susceptibility, despite the lack of mutation associated with resistance on FKS1, when reading was performed at 48 h (MIC(50)=3 µg/mL, MIC(90)=12 µg/mL). CONCLUSION: Prevalence of C. orthopsilosis and C. metapsilosis in patients with candidemia is low at Nantes University Hospital. The difficulty encountered with MIC reading by E-test(®) are discussed.

[Contribution of molecular biology and Aspergillus galactomannan antigen assay for the diagnosis of histoplasmosis]. / Contribution de la biologie moléculaire et de l'antigénémie galactomannane aspergillaire au diagnostic de l'histoplasmose.

We report a case of a pulmonary histoplasmosis in an HIV-positive patient usually living in Cambodia, with a positive Aspergillus galactomannan antigenemia resulting from a cross-reaction, that decreased after antifungal therapy. We discuss the potential interest of the detection of fungal DNA by PCR and Aspergillus galactomannan antigenemia for the diagnosis of histoplasmosis, especially in countries where Histoplasma capsulatum antigen testing is not available.

[Evaluation of toxoplasmosis seroprevalence among 2416 women of childbearing age followed at the Pasteur Institute of New Caledonia]. / Estimation de la séroprevalence de la toxoplasmose chez 2 416 femmes en âge de procréer suivies à l'Institut Pasteur de Nouvelle-Calédonie.

Evaluation of Toxoplasmosis seroprevalence was conducted in 2416 women of childbearing age by Pasteur Institute of New-Caledonia. The estimated seroprevalence was 56.7%, significantly higher in the North-East part of the territory (79.1%), area characterized by strong precipitations, and in the Melanesian ethnic group (62.1%). The habits of this population could enhance contamination by ingestion of oocysts during childhood or adolescence, particularly in the North-East territory. Melanesian women living in the North-East and being not immunized against toxoplasmosis represent the population with the highest risk for Toxoplasma gondii infection.

[Cyclospora cayetanensis presence in aquatic surroundings in Hanoi (Vietnam). Environmental study (well water, lakes and rivers)]. / Cyclospora cayetanensis et sa présence en milieu hydrique à Hanoï (Vietnam). Etude dans l'environnement (eaux de forage, lacs et rivières).

Cyclospora cayetanensis is a pathogenic agent originating from the intertropical zone. It causes diarrhoeal diseases in local populations as well as in travellers visiting these zones. In the first part of this work, an epidemiological study on drinking water supply (reservoirs and consumers' taps) was conducted in Hanoi over 12 months; samples were daily collected and have revealed the presence of Cyclospora cayetanensis oocysts during the whole year in tanks and only during monsoon season. Molecular methods were used for species identification. In the second part, we tried to investigate different water sources in Hanoi city in order to detect Cyclospora cayetanensis environmental contamination: groundwaters, surface waters collected in lakes and rivers and also waters from treatment plants. Our results show that none Cyclospora cayetanensis oocyst was found in the groundwaters and in the desinfected finished waters after treatment. In contrast, in rivers and lakes samples, the level of positivity reached about 63.6% with significant differences between the districts regarding the rates of oocysts recovery: only 24% positive specimens in Hoan Kiem district, whilst respectively 80.4%, 78.3% and 65% positive samples in Hai Ba Trung, Dong Da and Ba Dinh districts. The results of this study seem to confirm that environmental water is contaminated by Cyclospora cayetanensis oocysts and points out the importance of water as a significant source of human transmission. It is quite obvious that observation could be probably extended to the other endemic areas.

Development of an immunomagnetic separation-polymerase chain reaction (IMS-PCR) assay specific for Enterocytozoon bieneusi in water samples.

AIMS: Microsporidia have become widely recognized as important human pathogens. Among Microsporidia, Enterocytozoon bieneusi is responsible for severe gastrointestinal disease. To date, no current therapy has been proven effective. Their mode of transmission and environmental occurrence are poorly documented because of the lack of detection methods that are both species-specific and sensitive. In this study, we developed a sensitive and specific molecular method to detect E. bieneusi spores in water samples. METHODS AND RESULTS: The molecular assay combined immunomagnetic separation (IMS) and polymerase chain reaction (PCR) amplification to detect E. bieneusi spores. A comparison was made of IMS magnetic beads coated with two different monoclonal antibodies, one specific for the Encephalitozoon genus that cross-reacts with E. bieneusi and the other specific only for the E. bieneusi species itself. CONCLUSIONS: Immunotech beads coated with the antibody specific for E. bieneusi were found to be the most effective combination. SIGNIFICANCE AND IMPACT OF THE STUDY: The highly specific IMS-PCR assay developed in this study provides a rapid and sensitive means of screening water samples for the presence of E. bieneusi spores.

Adherence of platelets to Candida species in vivo.

The in vivo interactions of platelets with Candida species yeast cells were investigated in a murine model. Mice were injected intravenously via the lateral caudal vein, and blood drawn by periorbital puncture was collected in phosphate-buffered saline-formaldehyde to avoid in vitro platelet activation. The study of the clearance of blastoconidia of Candida albicans and Candida glabrata showed that these cells disappeared quickly from the bloodstream. Microscopic observation of blood samples, stained by Calcofluor white or May Grunwald Giemsa, demonstrated the rapid attachment of platelets to fungal elements of all the Candida spp. tested. The attachment of murine platelets to C. albicans cells, observed by scanning electron microscopy, revealed morphological changes. The platelets lost their discoid shape, generated pseudopodia, and flattened against the yeast cells. The reversibility of platelet binding to C. albicans by chelating agents suggests a cation-dependent link. In contrast, the fixation of C. glabrata and Candida tropicalis was not modified by chelating agents. The mechanisms involved in the in vivo adherence of platelets to Candida cells may therefore differ according to the species of Candida.

[Pseudallescheria boydii osteoarthritis in a patient with acute lymphoblastic leukemia: a case report]. / Ostéoarthrite à Pseudallescheria boydii chez un patient porteur de leucémie aiguë lymphoblastique: à propos d'un cas.

INTRODUCTION: The outcome of neutropenic patients with Pseudallescheria boydii infection is poor. EXEGESIS: We report the first case of Pseudallescheria boydii hip arthritis in a patient treated for acute lymphoblastic leukemia. In vitro susceptibility testing showed that the strain was resistant to amphotericin B, fluorocytosine and nystatin, but susceptible to itraconazole. The patient received oral itraconazole (600 mg/day) and clinical symptoms initially resolved. Two months later, after a course of chemotherapy and high-dose steroids while receiving oral itraconazole treatment, the patient developed fever, skin lesions and disseminated lung infiltrates due to Pseudallescheria boydii and finally died. CONCLUSION: This case illustrates the severity of fungal infections due to Pseudallescheria boydii despite a presumably well-conducted antifungal therapy.

[Optimization of parasitological diagnosis of human intestinal microsporidiosis]. / Optimisation du diagnostic parasitologique des microsporidioses intestinales humaines.

The diagnosis of microsporidiosis by staining stools is known to be fast and cheap. To obtain a specific and sensitive result, two colorimetric methods must be used: staining by the fluorochrome Uvitex 2 B (VAN GOOL) and trichrome. Among the four staining methods of trichrome currently studied, the WEBER coloration could be considered as the most efficient. The density of microsporidia spores could be semi-quantitatively evaluated, because their distribution is homogeneous.

Binding of resting platelets to Candida albicans germ tubes.

The binding of resting platelets to Candida albicans germ tubes was studied by means of an affinity column in which germ tubes were physically immobilized. Adhesion of platelets to the column was dependent on both the germ tube concentration and the number of platelets applied. It was found that the interaction of C. albicans germ tubes with platelets is specific and should be mediated by a fungal protein receptor. The results obtained by scanning electron microscopy confirmed that resting platelets can fix directly onto germ tubes. In addition, this study showed that attachment of platelets onto C. albicans is associated with morphological changes. Platelets lost their discoid shape, became globular, generated spikes or pseudopods, and then flattened on the yeast cells.

[Fusaria infection in patients with neutropenia: apropos of 3 cases]. / Infection fusariale chez le neutropénique: à propos de trois observations.

The authors report three cases of fusarial infection in neutropenic patients with hematologic malignancies. The first patient was affected by a cutaneous extensive fusariosis. The second patient developed a fusarial lung infection during a multiple organ failure following allogenic bone marrow transplantation. The third patient who presented with refractory acute myelogenous leukemia, developed fusarial skin lesions, and died from pulmonary failure. The treatment of fusarial infection is disappointing and requires amphotericin B, in association with hematopoietic growth factors. The role of new agents, or combination chemotherapy remains to be determinated. The recovery of adequate neutrophil levels is the most important factor in the resolution of fusarial infection.

[Anisakiasis in the Nantes area. From fishmongers' stalls to medical offices]. / L'anisakiase dans la région nantaise. De l'étal du poissonnier au cabinet du médecin.

1,103 fish-fillets belonging to 4 species were examined during one year, during a survey conducted among commercial marine fish-fillets in the Nantes area (west coast) in France. Anisakis simplex L3 were found in 3 different species and most of them are frequently present in coal fish (Pollachius virens) and whiting (Merlangius merlangus). We report 6 cases of human anisakiasis (3 certain cases and 3 probably cases). Diagnosis was established in 3 cases by microscopic analysis of intestin bowel specimens (eosinophilic granulomas and/or parasitic fragments) and in 3 cases gastroscopy. Serodiagnosis was positive in 1 case and the consumption of undercooked fishes was found in 5 cases. This work emphasizes the role of anisakiasis as a source of digestive symptoms and intestinal eosinophilic granuloma.