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Resume Objectif Enterocytozoon bieneusi est le principal agent responsable de diarrhees chroniques et de malabsorption chez les sujets VIH positif. Son epidemiologie est encore mal connue. Materiel et methode Nous avons effectue une etude comparative par PCR suivie d'un sequencage de 12 selles de six patients de la region nantaise. Resultats Cette etude a permis de retrouver une predominance de genotype B (5/6) ainsi qu'un genotype encore inconnu (1/6) correspondant respectivement au type I et au type IV. L'etude retrospective sur un et deux ans pour trois patients confirme que ces patients seraient toujours porteurs de la meme souche.

The in vivo interactions of platelets withCandidaspecies 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 ofCandida albicansandCandida glabratashowed 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 theCandidaspp. tested. The attachment of murine platelets toC. albicanscells, 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 toC. albicansby chelating agents suggests a cation-dependent link. In contrast, the fixation ofC. glabrataandCandida tropicaliswas not modified by chelating agents. The mechanisms involved in the in vivo adherence of platelets toCandidacells may therefore differ according to the species ofCandida.

Pseudallescheria boydii arthritis in a patient with acute lymphoblastic leukemia: a case report. 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.

Resume Vingt cas de microsporidioses chez des patients seropositifs pour le VIH ont ete etudies de facon retrospective. Ils representent l'ensemble des cas diagnostiques entre janvier 1993 et mai 1995 au CISIH de Nantes. Les cas etaient identifies par la coloration du trichrome (technique de Weber) et confirmes par l'Uvitex 2B (technique de van Gool). L'incidence a ete estimee a 2,9 % de l'ensemble de la file active du CISIH. Les examens coprologiques etaient effectues, le plus souvent, sur l'existence d'une diarrhee. Tous les patients etaient au stade C de la classification du CDC. La perte de poids moyenne etait de 2,56 kg/mois. Differents traitements ont ete tentes chez ces patients, sans aucun succes clinique ou parasitologique. Des co-pathogenes etaient identifies chez 5 patients (25 %). Cette etude permet de mieux cerner l'incidence de la microsporidiose au cours de l'infection a VIH dans une population non selectionnee. Par ailleurs, elle met en avant la necessite d'etudes ulterieures sur le reservoir et le mode de transmission de ce germe.

A partir de l'observation au CHU de Nantes du cas d'un patient presentant une diarrhee abondante, au retour d'un voyage du Vietnam, la recherche de l'agent etiologique suivie d'une enquete epidemiologique est menee par l'auteur. L'examen coprologique met en evidence la presence d'une coccidie de decouverte recente, du genre Cyclospora, et dont le mode de contamination, demeure jusqu'a present inconnu. L'investigation epidemiologique a montre une frequence elevee de diarrhees (11 cas sur 39). Parmi les personnes ayant participe au voyage, la presence de Cyclospora fut detectee sur les selles de 8 patients sur 25 analysees. Chez ceux-ci, la prise d'un jus d'orange reconstitue avec l'eau du robinet a Hanoi, quelques jours avant leur retour en France, constitue une caracteristique commune. L'eau du reseau d'Hanoi semble donc etre a l'origine de cette cascade de gastro-enterites chez ces voyageurs, de la region nantaise. La transmission hydrique de ce nouvel agent pathogene, ainsi que la notion de dose infestante sont evoquees devant cette pathologie digestive decrite chez les immunocompetents et dont l'evolution est favorable en absence de traitement. Les cas les plus severes se resolvent facilement avec un traitement au Bactrim.

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.

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).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 (MIC2 μg/mL) were analyzed for the presence/absence of FKS1 mutations associated with resistance.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).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.

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.

Resume L'interet de la scintigraphie pulmonaire aux radio-aerosols de diethylenetriamine-pentacetate marque au Technetium 99 a ete evalue prospectivement chez 60 patients infectes par le virus de l'immunodeficience humaine. Soixante-dix explorations ont ete realisees : dans 52/70 cas il n'existait aucun signe clinique et/ou radiologique pulmonaire. La scintigraphie pulmonaire etait normale 37 fois et objectivait 15 fois une alteration de la permeabilite alveolo-capillaire ; le lavage bronchiolo-alveolaire, realise 7/15 fois mettait en evidence une pneumocystose et 2 fois la presence de cytomegalovirus. Dans 18/70 cas, il n'existait pas de signes cliniques et/ou radiologiques pulmonaires, la scintigraphie au DTPA-Tc 99m etait pathologique 15 fois ; le lavage bronchiolo-alveolaire realise 13 fois, objectivait du Pneumocystis carinii 6 fois, du cytomegalovirus 2 fois, et un pneumocoque 1 fois. Confronte aux donnees cliniques, de la radiographie thoracique, aux resultats du lavage bronchiolo-alveolaire et a l'evolution clinique, cet examen apparait d'une grande sensibilite pour depister les pneumopathies infectieuses survenant chez ces patients, notamment les pneumocystoses, parfois meme a un stade infraclinique. Sont discutes la place de la scintigraphie pulmonaire au DTPA-Tc 99m par rapport aux autres methodes d'investigation pulmonaire non invasives et son interet dans le suivi des patients asymptomatiques et/ou apres traitement d'une infection opportuniste.

Resume Nous rapportons trois cas d'infection fusariale survenue chez des patients neutropeniques porteurs d'une hemopathie. Le premier patient presente une fusariose cutanee extensive. Le deuxieme presente une fusariose pulmonaire participant a un tableau de defaillance multiviscerale apres allogreffe de moelle osseuse. Le troisieme patient, porteur d'une leucemie aigue myeloblastique refractaire, developpe une fusariose cutanee et decedera d'une defaillance respiratoire. Le traitement de l'infection fusariale est decevant et repose sur l'amphotericine B, souvent associee aux facteurs de croissance medullaire. Le role d'associations chimiotherapiques antifungiques et celui de nouveaux agents reste a determiner. C'est la sortie d'aplasie qui permet le controle de l'infection.

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.

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.

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.

Twenty-eight strains of the Microsporum gypseum complex isolated from humans and animals were studied. The perfect form was found for 25 of the isolates. Nannizzia incurvata was the species most frequently involved in human pathology, while Nannizzia gypsea was most frequently found on animal lesions. Nannizzia fulva was rarely involved pathologically and Nannizzia corniculata was not isolated during this study. It is surprising to note that this species was not found even though most of our strains (22/28) came from Africa. Reliable methods are not available for differentiating among the anamorphs, which are commonly called M. gypseum, Microsporum fulvum or Microsporum boullardii. The Sabouraud medium conventionally used for medical mycology makes almost no distinction among them. We found that the species could be easily distinguished by colonial and microscopic features when grown on Takashio medium. When strains are atypical, sexual reproduction remains the reference technique but, in most cases, Takashio medium makes it possible to avoid this long drawn-out procedure.

It is possible to elucidate the physiopathology of candidosis by evaluating the different parameters involved in the relationship between C. albicans and its hosts. The different steps of the host colonization which can be evaluated are: adherence, multiplication and dissemination through the organism. When this dissemination is via the blood stream, the yeasts interact with blood components such as fibrinogens1, fibronectin2, complements3, leukocytes and platelets. In vivo experiments show the attachment of C. albicans to platelet aggregates. In vitro, electron microscopic observations demonstrate that the platelets adhere, protrude spikes and finally spread and flattened on the upper fibrillar layer of the fungus.

The integumental surface of adult Schistosoma mansoni was studied by scanning electron microscopy (SEM) at 220 to 10,000 magnifications. SEM shows certain basic features such as spines in the oral sucker and the acetabulum which may facilitate rasping and attachment of the parasite to stay in the bloodstream of the definitive host. It seems likely that SEM visualization will be a means for differentiation some species of the genus Schistosoma.

Scanning electron microscopy has been used to study the morphology of seven species of protoplasts from yeasts. In all species examined grooves and droplets were seen advancing with time but their interpretation still remains indefinite.

Radiopaque concretions in the maxillary sinus in cases of sinusitis are often observed in infections with aspergillosis. For several authors, such features are considered to be typical of these infections. For us this foreign body in most cases is believed to be related to overfilling of the teeth. We have previously drawn attention to this fact. We report 85 cases of aspergillosis of the maxillary sinus. Cases involving immunosuppressed patients were excluded because of very different clinical conditions. A radiopaque foreign body was seen in 94% of the cases. Of this group, 85% were believed to be related to overfilling of maxillary teeth with dental paste, particularly since evidence for endodontic treatment was found in the premolar/molar region. An image of intrasinus dental paste was demonstrated in 12% of the cases as a direct extension of filling paste from affected teeth. The nature of the dental paste is important because the zinc contained can stimulate the growth of Aspergillus fumigatus. In vitro studies in our laboratory also showed that the growth of A. fumigatus was stimulated with a low concentration of zinc.

The adult stages of Litosomosoides carinii, Dirofilaria uniformis and Dirofilaria immitis have been successfully maintained in vitro though microfilaria production by the worms continued only for a period of one to 18 days. In this paper we describe the results obtained in a series of experiments in which adult L1 and L2 stages of Dipetalonema viteae were maintained in vitro.

We can tell after observing the resulting negative that yeasts are able, in our experimental conditions, to collect a sequence of ADN and of ARN proceeding from the cancerous cells. Then, those yeasts could turn their synthesis towards the production of new materials. If those informed yeasts were introduced into a mouse, they would induce at the level of the immunocompetent cells a specific immunizing antitumoral power.

Surface tegumental membrane of adult stage Schistosoma mansoni were examined using the latex sphere coated with Concanavalin A (Con A). Wheat germ agglutinin (WGA) and Protein A (PA). Competitive saccharide inhibitors glucose, mannose and methyl alpha-D-glucopyranoside were used for Con A.

In a previous study we described the minimal methodology used to obtain protoplasts from ascomycetous yeasts. Using a reducing agent associated with 1,3-beta-glucanase at 26 degrees C, protoplasts were invariably obtained. In the present study we localized the disruption spots of the cell wall using the two same reagents. The observations were made with the scanning electron microscope. The disruption site was always in the subterminal region, and this very simple structure (proteins with disulphide bridges and 1,3-beta-glucans) was opposite the birth-scar. The dissociation of the two reagents showed that a small part of the yeast population was able to release protoplasts with only glucanase. We believe these very sensitive yeasts (2 to 10% population) to be very young cells. These disruption sites seemed very different from budding-sites. They might be identical with elongation-sites, or with the opening in the ascus-wall during germinating ascospore release.

The integumental surface on the microfilaria of Dipetalonema viteae was studied by scanning electron microscopy (SEM) at 1,200 to 20,000 magnification. This first study only concerns microfilaria in the circulating blood of the Hamster.

Studies performed in vivo and in vitro, using scanning electron microscopy, on relations between Schistosoma mansoni and some enterobacteria show a strong association for certain bacterial strains (Salmonella typhimurium). Salmonellae adhesion on tegumental surface of male and mature Schistosoma is only possible in vitro owing to bacterial synthesis of strong fibres penetrating inside the worm. These interactions are not found with Escherichia coli, Proteus mirabilis or with young schistosomula.

The optical microscopy (on histological preparations) and scanning observations of Schistosoma mansoni is conducted in the presence of various species of Salmonella. It is well-obtained that the Schistosoma maturity, its metabolic activity and the action of antibodies anti-salmonella have influenced the bacterian fixation on the worm. An hypothesis about the possible mechanism of this attachment is then developed and also an hypothesis about the protection of bacteria against antibiotherapy among patients infected with Schistosoma and carriers of salmonellosis.

The integumental surface of cercaria (Schistosoma mansoni was studied by scanning electron microscopy (SEM) at 400 to 20,000 magnifications. Cercariae studied by SEM showed clearly the surface topography. The spines have been seen by light microscopists and recognised as an adaptation for penetration of the host.

Dipetalonema viteae is a filarial that can evoluate among hosts zoologically broadly apart (Ixodides and Argasides), but always gathered from meriones burrows. Its evolution is, on the contrary, blocked among most of the other ticks, particularly among Ornithodoros erraticus morphologically very similar to the normal vector. Our work concerns the experimental deviation of the cycle of Dipetalonema viteae, with its possible adaptability in the bosom of an intermediate of fowl tropism and a permanent host, different from a gnawing.

Study by scanning electron microscopy enables us to describe with precision the morphology of protoplasts. We can confirm that the wrinkles more or less perceptible on the protoplasts studied, do belong to the morphology of those just mentioned, that the presence or the absence of globulous component is connected with the physiological activity of the cell and that it is possible to distinguish the different protoplasts thanks to their morphological aspect.

If the description in the literature is based on a study with the light microscope, in this work, with electron microscope scanning, the integumental surface on the larva of Dipetalonema viteae is studied at 1,500 to 50,000 magnifications.

Special interaction between Salmonella typhimurium (STM) and Schistosoma mansoni is considered under two complementary aspects, in vivo and in vitro, using scanning and transmission electron microscopy. The resulting observations have obviously permitted us to discover a large specificity in these adhesion phenomena that seems to lead to the fusion of membranes between the two organisms. Microanalysis trials executed in these areas of strong affinity were attempted.

From our observation in vitro, we can suggest that : a direct contact between sarcomatous cells and physiologically active yeasts appears to be necessary for the transfer of the radioactive labelling; the presence of a filter with pores of 1.2 micrometer diameter prevents passage of fragments of DNA or RNA between the cells; this transfer is a very small fact, but implies about the third of the yeasts.

Relations between Schistosoma mansoni and Salmonella typhimurium are studied in vivo and in vitro using scanning and transmission electron microscopy as complementary methods. Salmonellae adhesion is a specific process materialized in special places of male and mature schistosome tegumental surface. Interactions are marked by bacterial strong fibres creating a network all around Schistosoma where Salmonellae are dividing. Membrane junction is the last stage leading to symbiotic balance between two biologic systems.

In our attempts to elucidate the pathogenesis of prolonged Salmonella bacteremia in patients with Schistosoma mansoni or Schistosoma haematobium infection, we have utilised MEB. Our results are significant. They show an association exists between Bilharziasis and Salmonellosis.

The authors describe a case of febrile disease acquired by a nursling in Africa: was it induced by Pl. falciparum or by Babesia sp.? In spite of numerous microscopic and serological appraisals from veterinary and medical authorities, it is difficult to state definitively this subject, but it is more probably a babesiosis of canine or rodent origin.