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Biomedical subjects

A Paugam

Publications and source records attributed to A Paugam.

At least 19 recordsLinked to original sources

Clinical and experimental evaluation of a new chromogenic medium (OCCA, Oxoid) for direct identification of Candida albicans, C. tropicalis and C. krusei.

Oxoid Chromogenic Candida Agar (OCCA) is a new commercial ready-to-use medium that contains chromogenic substrates for rapid detection and specific identification of Candida albicans, C. tropicalis and C. krusei. We evaluated the performance of this medium with 364 clinical specimens and 31 subcultures, and examined its ability to support the growth of small inocula of six reference strains. CHROMagar Candida was used as the reference medium. OCCA permitted the growth of most important yeasts, and readily discriminated among Candida spp. in clinical specimens, including mixed cultures.

Candida↗

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.

Amphotericin B↗

[Mycologic surveillance of the environment for preventive invasive aspergillosis. Proposals for standardization of the methodologies and implementation].

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.

Air Microbiology↗

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.

Animals↗

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.

Adult↗

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.

AIDS-Related Opportunistic Infections↗

Comparison of four commercialized biochemical systems for clinical yeast identification by colour-producing reactions.

We compared the ability of four commercially available yeast identification systems for routine laboratory hospital use: Auxacolor (AUX) (Sanofi Diagnostics Pasteur, Marne-la-Coquette), Fungichrom I (FUC) and Fungifast I Twin (FUF) (International Microbio, Toulon), Api Candida (API) (bioMérieux, Lyon). These systems are based on obtaining a biochemical profile easily defined by colorimetric reactions. We tested 202 yeasts belonging to 19 species which were included or were not included in the manufacturer's data base of the identification systems. Without extra tests, for all the organisms tested, after 24 h of incubation, the percentage of organisms correctly identified was 48% for AUX, 75% for FUC, 77% for FUF and 81% for API. However, if we consider the ratio of the number of correct identifications without extra tests with the number of yeasts included in the manufacturers' data bases (sensitivity) the results increased to 61% for AUX, 81% for FUC, 91% for FUF and 83% for API. These systems are particularly well adapted to medical use, they are simple to set up, interpret, and have very good efficiency for the yeasts most commonly isolated in clinical specimens. The findings reported here indicate that the most favourable results were obtained with FUF and API systems.

Colorimetry↗

Detection of Aspergillus galactomannan: comparison of an enzyme-linked immunoassay and a europium-linked time-resolved fluoroimmunoassay.

With a view to improving the sensitivity of serological detection of Aspergillus galactomannan (GM), a europium-linked time-resolved fluoroimmunoassay was developed. This method was compared to an enzyme-linked immunosorbent assay using a peroxidase-conjugated detector antibody. No increase in the sensitivity of the detection of GM standards was seen with the europium-based fluoroimmunoassay.

Antigens, Fungal↗

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.

AIDS-Related Opportunistic Infections↗

[Contribution of air mycological control for the prevention of invasive nosocomial aspergillosis].

This study analyses the results of systematic air sampling during 11 months in hospital areas where patients are particularly exposed to Invasive Nosocomial Aspergillosis (INA). The results demonstrate that isolement of Aspergillus fumigatus is occasional and allows the control and validation of cleaning, disinfection and filtration measures. The efficiency of this protocol suggests its prophylactic value in INA.

Air Microbiology↗

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.

Administration, Oral↗

[Detection of trypanosomes in blood by the Quantitative Buffy Coat (QBC) technique: experimental evaluation].

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.

Animals↗

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.

Abdominal Pain↗

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.

Animals↗

Use of random amplified polymorphic DNA as a typing method for Candida albicans in epidemiological surveillance of a burn unit.

Burn patients are particularly exposed to deep-seated nosocomial infections caused by Candida species. Superficial carriage of C. albicans is a potential source of infection and dissemination, and typing methods could be useful to trace the different isolates. We report the use of random amplified polymorphic DNA to type isolates of C. albicans in the Hôpital Cochin burn unit. This molecular typing method, which is based on PCR with arbitrary short primers, was evaluated on a panel of 32 C. albicans strains isolated from various anatomical sites of unrelated patients, and the strains showed 22 different patterns. Random amplified polymorphic DNA was then used in the epidemiological surveillance of the patients in the burn unit over a 9-month period. Seven patterns were identified among 84 isolates from 18 patients. One pattern (pattern A) corresponding to isolates from 7 of the 18 patients (68% of isolates) predominated throughout the 9-month study, while some strains with other profiles were isolated only once. Some profiles appeared to show a particular geographic pattern within the unit, suggesting transmission from room to room. These results underline the importance of fungal surveillance in such patients and the need to inform nursing staff of measures to prevent the spread of Candida spp. from patient to patient.

Burn Units↗