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Biomedical subjects

M A Piens

Publications and source records attributed to M A Piens.

At least 37 records · Page 2Linked to original sources
PubMed2001

Genetic polymorphism of Aspergillus fumigatus in clinical samples from patients with invasive aspergillosis: investigation using multiple typing methods.

The genotypes of 52 strains of Aspergillus fumigatus isolated from 12 patients with invasive aspergillosis were investigated using three typing methods (random amplified polymorphic DNA, sequence-specific DNA polymorphism, and microsatellite polymorphism) combined with multilocus enzyme electrophoresis. Isolates were from patients hospitalized in three different geographic areas (Lyon, France; Grenoble, France; and Milan, Italy). In each case, the genetic polymorphism of several colonies (two to five) within the first respiratory clinical sample was studied. For the 52 isolates tested, random amplified polymorphic DNA identified 8 different genotypes, sequence-specific DNA polymorphism identified 9 different types, and microsatellite polymorphism identified 14 types. A combination of these results with multilocus enzyme electrophoresis study identified 25 different types within the sample studied. We identified 3 patients (of the 12 studied) who carried a single genotype; 6 patients were infected by two genotypes, 1 patient had four genotypes, while the last patient had five. A combination of typing methods provided better discrimination than the use of a single method. Typing methods revealed a population structure within each geographical site, suggesting that the epidemiology of A. fumigatus should be considered separately for each of these geographic areas. This study demonstrates the usefulness of combining several typing methods in reaching an understanding of the epidemiology of A. fumigatus and clarifies whether it is sufficient to type one isolate from each specimen to determine the strain involved in invasive aspergillosis.

Aspergillosis↗
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

Intestinal microsporidiosis occurring in two renal transplant recipients treated with mycophenolate mofetil.

BACKGROUND: Intestinal microsporidiosis is a major cause of chronic diarrhea and malabsorption in patients with human immunodeficiency virus. Its occurrence in transplant recipients has exceptionally been reported to date. METHODS: We report what we believe are the first two cases of intestinal microsporidiosis in renal transplant recipients. The patients were treated with mycophenolate mofetil. RESULTS: The clinical presentation was chronic diarrhea with massive weight loss. Stool analysis revealed microsporidian spores, identified as Enterocytozoon bieneusi spores by polymerase chain reaction. The onset of this opportunistic infection in these two patients is believed to be secondary to an increase in immunosuppression after azathioprine replacement by mycophenolate mofetil. The withdrawal of mycophenolate mofetil led to clinical recovery. CONCLUSION: The incidence of microsporidiosis will probably increase in transplant recipients treated with powerful immunosuppressants. Therefore, we recommend a systematic search for microsporidian spores in stool specimens in cases of unexplained diarrhea in these patients.

Adult↗
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

[Late cryptococcal meningitis after liver transplantation].

We report a case of cryptococcal meningitis, eight years after liver transplantation for primary biliary cirrhosis. Detection of the cryptococcal antigen in serum and cerebrospinal fluid appears to be essential for initial diagnosis and follow-up. Oral fluconazole treatment alone can be effective, when given for a very long period to prevent relapse.

Female↗
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↗
PubMed1998

[Parasitic eosinophilic lungs].

The eosinophilic lung is a term used to identify a heterogeneous group of parasitic diseases leading to common manifestations including alveolar or tissular pulmonary eosinophilia and, classically, radiological visible lesions of the lung. The different clinical presentations--Löffler's syndrome, larva migrans syndrome and tropical pulmonary eosinophilia are analyzed in this article and the particular features of the different causal parasites are discussed. Positive and differential diagnostic procedures in patients with pulmonary eosinophilia due to mycoses, drugs, vasculitis or an unknown cause are detailed.

Adult↗
PubMed1997

Evaluation of the E test for fluconazole susceptibility testing of Candida albicans isolates from oropharyngeal candidiasis.

The aim of the present study was to evaluate the utility of the E test in determining the antifungal susceptibility of Candida albicans. Reproducibility of the E test was determined for amphotericin B, fluconazole, and itraconazole using three different solid media: RPMI 1640, Casitone, and yeast nitrogen base agar. Minimum inhibitory concentrations (MICs) were comparable (results at +/- 2 dilutions) in 92% of the tests for amphotericin B and in 100% for fluconazole and itraconazole. Determination of MIC endpoints was easiest on Casitone agar. Candida albicans isolates from 23 patients undergoing fluconazole therapy for oropharyngeal candidiasis were tested for fluconazole susceptibility. Good correlation was obtained between the MICs of fluconazole and clinical outcome. Clinical failure was associated with strains for which MICs were > or = 48 micrograms/ml. These results suggest that the E test has potential utility for fluconazole susceptibility testing of clinical yeast isolates.

Amphotericin B↗
PubMed1997

Fluconazole susceptibility of Candida isolates from oropharyngeal candidosis.

Fifty strains of Candida isolated from 38 patients with oropharyngeal candidosis were tested in vitro for fluconazole susceptibility with a disk diffusion test and for determination of minimal inhibitory concentrations (MICs). For 25 patients treated with fluconazole, the relationship between in vitro susceptibility and clinical outcome was analysed. A good correlation between in vitro results and therapeutic efficacy was found. In only one case was treatment failure associated with a susceptible strain. Mixed cultures of Candida albicans and non-albicans Candida species were not uncommon and, more interestingly, some samples contained different strains of C. albicans with varied fluconazole susceptibilities. Good agreement was observed between the two techniques used for fluconazole susceptibility testing.

Antifungal Agents↗
PubMed1997

Molecular typing of Aspergillus fumigatus strains by sequence-specific DNA primer (SSDP) analysis.

A PCR typing method has been developed and tested to investigate the polymorphism of clinical strains of Aspergillus fumigatus. Firstly, the DNA fragments from random amplified polymorphic DNA (RAPD) patterns of nine epidemiologically and geographically non-related monosporal strains of A. fumigatus were cloned and sequenced. The pairs of five sequence-specific DNA primers (SSDP), characteristic of the 5' and 3' extremities of the RAPD products, were then used in high stringency PCR to type 43 clinical strains of A. fumigatus from 13 patients, according to the presence or absence of a single amplified band. This original approach, which uses the advantages of PCR, has made it possible to overcome the difficulties resulting from the low stringency amplification. The SSDP analysis of 51 A. fumigatus strains (9 unrelated monosporal strains and 43 clinical strains from 13 patients) can be classed into 22 different types with a high reproducibility and a high level of discrimination (D = 0.96). The results suggest that seven lung transplant patients with necrotizing aspergillosis, bronchitis aspergillosis and bronchial colonization were infected by multiple strain genotypes, whereas three patients with invasive aspergillosis seem to have been infected by a single strain.

Aspergillosis↗
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↗