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F Persat

Publications and source records attributed to F Persat.

At least 19 recordsLinked to original sources
PubMed2006

Toxoplasma gondii: comparison of human CD34+ and monocyte-derived dendritic cells after parasite infection.

Human dendritic cells (DC) obtained in vitro from CD34(+) progenitors (CD34-DC) or blood monocytes (mo-DC) are different DC which may be used in a model of T. gondii infection. We compared the survival, infection rate and cell surface receptor expression of both DC types after living T. gondii tachyzoite infection. CD34-DC appeared less resistant to the parasite than mo-DC. At 48h post-infection, chemokine receptors responsible for DC homing and migration were absent in mo-DC, while down regulation of CCR6 and up regulation of CCR7 was observed in CD34-DC. This result, suggesting migration ability of CD34-DC, was confirmed by in vitro migration experiments against different chemokines. Tachyzoite supernatant, used as chemokine, attracted immature CD34-DC as observed by MIP3alpha, while MIP3beta, as expected, attracted mature CD34-DC. Under similar conditions, no significant difference was noticed between mature or immature mo-DC. These data indicated that CD34-DC represent an alternative model that allows migration assay of infected DC by T. gondii.

Animals↗
PubMed2005

Candida species distribution in bloodstream cultures in Lyon, France, 1998-2001.

In order to determine the types of Candida spp. isolated from bloodstream cultures in Lyon, France, a retrospective study of isolates collected at five different bacteriology laboratories from 1998 to 2001 was conducted. During this period Candida spp. were isolated from 190 patients hospitalized in the internal medicine (32%), hematology (23%) and surgery (23%) wards, and in intensive care units (22%). C. albicans was the leading cause of Candida infection (49.5%), followed by C. glabrata (12.6%) and C. parapsilosis (12.1%). Among the onco-hematology patients, the major cause of candidemia was C. krusei (34%), followed by C. albicans (19%), while these two species were identified in 4% and 59% of patients in the other wards, respectively. In the single onco-hematology ward that was specialized in treating acute myeloid leukemia, 14 C. krusei isolates were identified in this study, which contrasts with the single C. krusei isolate recorded between 1992 and 1996. Since C. krusei has inherent resistance to the antifungal agent fluconazole, prophylactic use of fluconazole in these patients was investigated, but no relationship between these two parameters was found.

Aged↗
PubMed2005

Toxoplasma gondii regulates recruitment and migration of human dendritic cells via different soluble secreted factors.

We investigated in vitro the properties of soluble factors produced by Toxoplasma gondii on the recruitment, maturation and migration of human dendritic cells (DC) derived from CD34+ progenitor cells. We used soluble factors including excreted secreted antigens (ESA) produced under various conditions by the virulent type I RH strain (ESA-RH) and the less virulent PRU type II strain (ESA-PRU). Soluble factors of both T. gondii strains appeared to possess a chemokine-like activity that attracted immature DC. This recruitment activity required the presence of functional CCR5 molecules on the cell membrane. Incubation of DC for 24 h with ESA triggered the migration of a large percentage of these cells towards the chemokine MIP-3beta; ESA-PRU was more efficient than ESA-RH. ESA produced in absence of exogenous protein and crude extract did not induce DC migration but retained recruitment activity. These data indicate that recruitment activity and migration-inducing activity are not governed by the same factors. Moreover, incubation of DC for 48 h with ESA did not modify the expression of costimulation or maturation markers (CD83, CD40, CD80, CD86 or HLA-DR), but induced a decrease in CCR6 expression associated with an increased expression of CCR7. Taken together, these results suggest that T. gondii controls recruitment and migration of immature DC by different soluble factors and may induce a dysfunction in the host-specific immune response.

Animals↗
PubMed2003

Binding of live conidia of Aspergillus fumigatus activates in vitro-generated human Langerhans cells via a lectin of galactomannan specificity.

Aspergillus fumigatus is the most common aetiological fungus responsible for human pulmonary aspergilloses. This study investigated the primary contact between Langerhans cells (LC), corresponding to dendritic cells present in pulmonary mucosa and live conidia of A. fumigatus. LC play a key role in antigen presentation for initiation of the primary T cell response. In vitro-generated LC (iLC) were differentiated from cultured human cord blood CD34+ cells and incubated at 4 degrees C or 37 degrees C with fluorescein-isothiocyanate (FITC)-stained conidia or control latex beads. In vitro, conidia were shown by microscopy and cytometry to adhere to iLC in a dose- and time-dependent manner. This adhesion was not limited to iLC because interstitial dendritic and other cells also fluoresced in the presence of conidia-FITC. A lectin other than mannose receptor-type lectin was demonstrated to be responsible of conidial binding. Inhibition of binding was observed with heterologous galactomannan and EDTA, indicating a C-lectin-like receptor with galactomannan structure specificity. After binding only a few conidia were internalized in acidic vesicles, as indicated by the cessation of conidial fluorescence. Conidial binding was followed by activation and maturation of iLC, suggesting that LC present in the lung may play a role in cellular host defence against aspergilloses.

Aspergillosis↗
PubMed2002

Evaluation of different commercial ELISA methods for the serodiagnosis of systemic candidosis.

Different commercial enzyme-linked immunsorbent assays (ELISA) were evaluated in a preliminary study for diagnosis of systemic candidosis: Biomerica and Virotech GmbH, which allowed immunoglobulin G detection, and Platelia, which associated total antibody to antigen detection. They were tested with a home-made ELISA and compared with the routine techniques used in the hospital laboratory: indirect immunofluorescence and counter-immunoelectrophoresis. Sera were obtained from patients with probable or proven systemic candidosis (groups 3 and 4, n=8 and n=14, respectively) and from patients without systemic candidosis who were divided into controls (n=10), those hospitalized without Candida isolation (group 1, n=10) and those hospitalized with Candida isolation in a peripheral site (group 2, n=18). The immunoglobulin G ELISAs showed a higher sensitivity associated with lower specificity compared to the indirect immunofluorescence, counter-immunoelectrophoresis and total immunoglobulin ELISAs. Mannan antigen detection showed the highest specificity (78.9%). Its association with the detection of total anti-Candida immunoglobulins was more sensitive than the association of indirect immunofluorescence with counter-immunoelectrophoresis (95.4% versus 59%, respectively) with a specificity of 52.6% (versus 55.2%). Interest in the use of commercial ELISAs, more particularly the Platelia tests, has to be confirmed in a prospective study with follow-up of the patients.

Antibodies, Fungal↗
PubMed2001

Acquired itraconazole resistance in Aspergillus fumigatus.

The antifungal susceptibility profiles of four ASPERGILLUS: fumigatus isolates, recovered at different times from a patient treated with itraconazole for a pulmonary ASPERGILLUS: infection, were evaluated. Itraconazole MICs against two pre-treatment isolates were 0.5 mg/L, whilst two later isolates, recovered after at least 4 months of itraconazole therapy, had itraconazole MICs of >16 mg/L. In vivo susceptibilities to itraconazole and amphotericin B were tested in a murine model of disseminated aspergillosis. Treatment efficacy was evaluated by examining mortality rates and qualitative cultures of brain and kidneys. Itraconazole therapy significantly prolonged survival of mice infected with the initial isolates as compared with untreated controls. The third isolate was only partially susceptible to itraconazole in vivo, and the fourth isolate was highly resistant. The four isolates were typed by random amplified polymorphic DNA (RAPD) with four different primers. RAPD patterns obtained with each of them were identical, suggesting that the same strain was recovered over time and had acquired resistance to itraconazole.

Aged↗
PubMed2001

Sterol composition of itraconazole-resistant and itraconazole-susceptible isolates of Aspergillus fumigatus.

Sterol composition of four clinical isolates of Aspergillus fumigatus resistant to itraconazole was determined by gas chromatography--mass spectrometry and compared with that of four susceptible strains. For all strains, the major sterol was ergosterol. Sterol compositions were qualitatively and quantitatively similar for the resistant and susceptible strains. These results suggest that itraconazole resistance is not related, for the strains studied, to alterations in the ergosterol synthesis pathway.

Antifungal Agents↗
PubMed2000

Amphotericin B resistance of Aspergillus terreus in a murine model of disseminated aspergillosis.

The in-vivo activity of amphotericin B and itraconazole against a clinical isolate of Aspergillus terreus was determined in a murine model of disseminated aspergillosis. MICs of amphotericin B and itraconazole for the strain, determined by an NCCLS-based technique, were 2 microg/ml and 1 microg/ml, respectively. Mice infected intravenously were treated with either itraconazole (50 or 100 mg/kg/day) or amphotericin B 4.5 mg/kg/day for 10 days. Treatment with both doses of itraconazole significantly prolonged the survival rates compared with those for untreated mice. In comparison, mortality rate and median survival time were identical for mice treated with amphotericin B and for mice given no therapy, indicating that the strain was highly resistant to amphotericin B in this model. Analysis of sterol composition showed that the major sterol was ergosterol. This suggests that amphotericin B resistance was not related to a modified sterol profile.

Amphotericin B↗
PubMed1999

Waterborne outbreak of intestinal microsporidiosis in persons with and without human immunodeficiency virus infection.

Among 1454 persons whose stool samples (n=5692) were submitted to a reference laboratory for microsporidia assessment from 1993 to 1996, microsporidia were identified in 338 persons: 261 persons infected with human immunodeficiency virus (HIV), 16 transplant patients, and 61 others. Intestinal microsporidiosis appears to be an endemic disease in HIV-positive persons (prevalence, 0.1%) and a sporadic disease in HIV-negative persons (prevalence, <1/1 million). A waterborne outbreak in 200 persons (attack rate, 1% in HIV-positive patients/month) occurred in the 1995 summer, without evidence of fecal contamination of water. No explanation was found before the outbreak ended, several months before the antiprotease era. Factors associated with microsporidiosis diagnosis were HIV infection, male homosexuality, low CD4 cell counts, and diarrhea. The major factor associated with a diagnosis of microsporidiosis during the outbreak was living in an area corresponding to one of the three water distribution subsystems of the town. Lake contamination was suspected.

Adult↗
PubMed1999

In-vitro susceptibility of Aspergillus spp. isolates to amphotericin B and itraconazole.

The MICs of amphotericin B and itraconazole for 230 isolates of Aspergillus spp., comprising 156 Aspergillus fumigatus, 20 Aspergillus terreus, 22 Aspergillus flavus, 17 Aspergillus nidulans and 15 Aspergillus niger, were determined by a broth microdilution method with RPMI 1640 medium. No isolate was detected with an MIC of amphotericin B >2 mg/L. Itraconazole MICs >16 mg/L were detected for four Aspergillus fumigatus and one Aspergillus nidulans isolates.

Amphotericin B↗
PubMed1999

In-vivo itraconazole resistance of Aspergillus fumigatus in systemic murine aspergillosis. EBGA Network. European research group on Biotypes and Genotypes of Aspergillus fumigatus.

An animal model of disseminated aspergillosis was used to test the in-vivo activity of itraconazole against four isolates of Aspergillus fumigatus. Two reference isolates of A. fumigatus known to be resistant to itraconazole in vitro and in vivo were used as control isolates, and two new isolates were tested under the same conditions. For each isolate MICs for itraconazole and amphotericin B were determined by an NCCLS-based method. Mice infected intravenously were treated either with itraconazole 100 mg/ kg/day or amphotericin B 4.5 mg/kg/day for 10 days. Amphotericin B showed good in-vivo activity against all four isolates. For one strain, which had a low in-vitro MIC for itraconazole, in-vivo therapy with itraconazole prolonged the survival of mice and reduced fungal burdens in organs compared with untreated controls. In mice infected with a strain with a high MIC of >16 mg/L, itraconazole neither prolonged survival nor reduced fungal load in organs compared with controls. It is concluded that there is a relationship between MIC and treatment outcome in mice for A. fumigatus infection.

Amphotericin B↗
PubMed1999

Use of spectrophotometric reading for in vitro antifungal susceptibility testing of Aspergillus spp.

A comparative study of visual and spectrophotometric MIC endpoint determinations for antifungal susceptibility testing of Aspergillus species was performed. A broth microdilution method adapted from the National Committee for Clinical Laboratory Standards (NCCLS) was used for susceptibility testing of 180 clinical isolates of Aspergillus species against amphotericin B and itraconazole. MICs were determined visually and spectrophotometrically at 490 nm after 24, 48, and 72 h of incubation, and MIC pairs were compared. The agreement between the two methods was 99% for amphotericin B and ranged from 95 to 98% for itraconazole. It is concluded that spectrophotometric MIC endpoint determination is a valuable alternative to the visual reference method for susceptibility testing of Aspergillus species.

Amphotericin B↗
PubMed1998

Pharmacokinetics of itraconazole oral solution in allogeneic bone marrow transplant patients receiving total body irradiation.

A prospective study of the pharmacokinetics of itraconazole solution was performed in 11 patients who underwent allogeneic BMT (day of BMT = day 0) after a conditioning regimen including total body irradiation (TBI). Itraconazole solution (400 mg once a day) was given 7 days before BMT and continued up to the end of neutropenia unless another antifungal treatment was necessary. Blood samples were collected before itraconazole intake (Cmin) and 4 h later (Cmax) every other day for assays of itraconazole (ITRA) and its active metabolite hydroxy-itraconazole (OH-ITRA). The mean values of Cmin ITRA and OH-ITRA, respectively, were 287 +/- 109 ng/ml and 629 +/- 227 ng/ml at day -1 and 378 +/- 147 ng/ml and 725 +/- 242 ng/ml at day +1. The maximum Cmin values were observed at day +3. Six patients at day -1 (54%) and 8 at day +1 (72%) had satisfactory residual plasma concentrations of at least 250 ng/ml of unchanged ITRA. From day +1 to day +9, eight patients discontinued the itraconazole treatment, five of them had satisfactory plasma residual concentrations at this time. This work shows a good bioavailability of itraconazole oral solution during the early phase after allogeneic BMT, but more data are needed for the late phases.

Administration, Oral↗
PubMed1997

Detection of Pneumocystis carinii DNA by PCR amplification in various rat organs in experimental pneumocystosis.

Pneumocystosis is usually a disease of the lungs, but the number of cases of extrapulmonary pneumocystosis has greatly increased during the AIDS epidemic. Much remains unknown about the frequency and mechanisms of dissemination. In the present study, a systematic search for Pneumocystis carinii by PCR with primers specific for mitochondrial rRNA was performed in the lung, liver, spleen and kidney of 12 immunosuppressed rats and two immunocompetent rats. The amplified products were analysed by Southern hybridisation with a digoxigenin-11-dUTP labeled probe. P. carinii DNA was found in lungs in all 14 rats and in at least one organ other than lung in 11 immunosuppressed rats and the two control rats. We suggest that extrapulmonary dissemination may not be an exceptional phenomenon in the course of pneumocystosis, but rather part of the natural evolution of the disease.

Animals↗
PubMed1997

Rapid detection of Pneumocystis carinii in bronchoalveolar lavage specimens from human immunodeficiency virus-infected patients: use of a simple DNA extraction procedure and nested PCR.

We report on the development of a rapid nested PCR protocol for the detection of Pneumocystis carinii DNA in bronchoalveolar lavage (BAL) specimens in which the protocol included the use of a commercially available DNA extraction kit (GeneReleaser). GeneReleaser enabled us to obtain amplification-ready DNA within 20 min without requiring the purification of the DNA. The nested PCR was performed with the primers pAZ102-E, pAZ102-H, and pAZ102-L2 (A. E. Wakefield, F. J. Pixley, S. Banerji, K. Sinclair, R. F. Miller, E. R. Moxon, and J. M. Hopkin, Lancet 336:451-453, 1990.). Results were obtained in about 4 h with the adoption of denaturation, annealing, and extension steps shortened to 20 seconds. The sensitivity of the nested PCR was tested with a P. carinii cyst suspension and was found to be less than one cyst (one to eight nuclei). The detection limit was the same with the use of GeneReleaser or proteinase K-phenol chloroform for DNA extraction. The nested PCR assay was prospectively compared with staining with Giemsa and methenamine silver stains for the detection of P. carinii in 127 BAL samples from 105 human immunodeficiency virus-infected patients investigated for acute respiratory illness. Twenty-five BAL specimens (20%) were positive by staining and the nested PCR and 25 (20%) were negative by staining and positive by the nested PCR. These 25 BAL specimens with conflicting results were obtained from 23 patients, 82% of whom were receiving prophylactic therapy against P. carinii pneumonia (PCP). Only two patients were diagnosed with possible PCP. The final diagnosis was not PCP for 20 patients who were considered to be colonized or to have a low level of infection. This colonization is not of clinical importance but is of epidemiological importance. Our rapid, simple, and sensitive amplification protocol may be performed in clinical laboratories for the routine diagnosis of PCP with BAL specimens.

AIDS-Related Opportunistic Infections↗