Aspergillus antibody detection: diagnostic strategy and technical considerations from the Société Française de Mycologie Médicale (French Society for Medical Mycology) expert committee.

Until now, there has been no consensus on the best method for the detection of anti-Aspergillus antibodies, a key diagnostic tool for chronic aspergilloses. To better appreciate the usage of and confidence in these techniques, the Société Française de Mycologie Médicale (French Society for Medical Mycology; SFMM) performed a two-step survey of French experts. First, we administered an initial survey to French labs performing Aspergillus serology to depict usage of the different techniques available for Aspergillus serology. Second, an opinion poll was conducted of 40 experts via an online questionnaire. Each item was rated from 1 to 9 according to the level of agreement. The initial survey revealed that enzyme-linked immunosorbent assay (ELISA) (81%) and immunoelectrophoresis (IEP) (67%) were the most commonly used techniques for screening and confirmation, respectively. The distinction between screening and confirmation techniques was confirmed by the experts (median = 7) with a 44.2% variation coefficient. Only ELISA for screening and IEP and Western blot (WB) for confirmation were clearly considered valuable methods (median ≥8 with variation coefficients less than 30%). The use of a confirmation technique was recommended in the case of a positive result in a compatible clinical context (cystic fibrosis, for example) or during the patient's follow-up. In the case of discordant results between the screening and confirmation techniques, the experts recommended greater confidence in the results obtained with the confirmation technique. All experts emphasized the need to standardize Aspergillus serology techniques and to better define the place of each of them in the diagnosis of aspergillosis.

Prospective Evaluation of a New Aspergillus IgG Enzyme Immunoassay Kit for Diagnosis of Chronic and Allergic Pulmonary Aspergillosis.

Anti-Aspergillus IgG antibodies are important biomarkers for the diagnosis of chronic pulmonary aspergillosis (CPA) and allergic bronchopulmonary aspergillosis (ABPA). We compared the performance of a new commercial enzyme immunoassay (EIA) (Bordier Affinity Products) with that of the Bio-Rad and Virion\Serion EIAs. This assay is novel in its association of two recombinant antigens with somatic and metabolic antigens of Aspergillus fumigatus In a prospective multicenter study, 436 serum samples from 147 patients diagnosed with CPA (136 samples/104 patients) or ABPA (94 samples/43 patients) and from 205 controls (206 samples) were tested. We obtained sensitivities of 97%, 91.7%, and 86.1%, and specificities of 90.3%, 91.3%, and 81.5% for the Bordier, Bio-Rad, and Virion\Serion tests, respectively. The Bordier kit was more sensitive than the Bio-Rad kit (P < 0.01), which was itself more sensitive than the Virion\Serion kit (P = 0.04). The Bordier and Bio-Rad kits had similar specificity (P = 0.8), both higher than that of the Virion\Serion kit (P = 0.02). The area under the receiver operating characteristic (ROC) curves confirmed the superiority of the Bordier kit over the Bio-Rad and the Virion\Serion kits (0.977, 0.951, and 0.897, respectively; P < 0.01 for each comparison). In a subset analysis of 279 serum samples tested with the Bordier and Bio-Rad kits and an in-house immunoprecipitin assay (IPD), the Bordier kit had the highest sensitivity (97.7%), but the IPD tended to be more specific (71.2 and 84.7%, respectively; P = 0.10). The use of recombinant, somatic, and metabolic antigens in a single EIA improved the balance of sensitivity and specificity, resulting in an assay highly suitable for use in the diagnosis of chronic and allergic aspergillosis.

Invasive aspergillosis: an important risk factor on the short- and long-term survival of acute myeloid leukemia (AML) patients.

Invasive aspergillosis (IA) during induction chemotherapy of acute myeloid leukemia (AML) could worsen the prognosis. Our objective was to study how the development of IA during AML interferes with the therapeutic strategy and to evaluate its impact on the short- and long-term survival. Newly diagnosed AML patients between the years 2004 and 2007 were retrospectively analyzed. The outcome was death of the patient. A Cox proportional hazards model with the diagnosis of IA and post-induction response evaluation as the main exposure was fitted. Overall, 262 patients were analyzed and 58 IA were observed. The 2-year survival of patients having had remission of AML was 54% and, for patients with failure of chemotherapy, it was 5% (p < 0.001). The 2-year survival of patients having had IA was 14%, and without IA, it was 32% (p = 0.01). Multivariate analysis showed that IA was associated with a higher risk of death in case of remission compared to no IA (hazard ratio [HR] = 1.66 [1.05-2.65], p = 0.031) and also in case of failure (HR = 6.43, p < 0.001). IA was associated with an increased risk of death for patients if they were either in remission or in failure after induction chemotherapy.

Cerebral aspergillosis in the era of new antifungals: The CEREALS national cohort study Nationwide CEREbral Aspergillosis Lesional study (CEREALS).

BACKGROUND: Cerebral aspergillosis (CA) is a life-threatening disease for which diagnosis and management remain challenging. Detailed analyses from large cohorts are lacking. METHODS: We included 119 cases of proven (n = 54) or probable (n = 65) CA diagnosed between 2006 and 2018 at 20 French hospitals. Data were collected at baseline and during follow-up. Cerebral imaging was reviewed centrally by two neuroradiologists. RESULTS: The most frequent underlying conditions were hematological malignancy (40%) and solid organ transplantation (29%). Galactomannan was detected in the serum of 64% of patients. In 75% of cases, at least one of galactomannan, Aspergillus PCR, and ß-d-glucan was positive in the cerebrospinal fluid. Six-week mortality was 45%. Two distinct patterns of disease were identified according to presumed route of dissemination. Presumed haematogenous dissemination (n = 88) was associated with a higher frequency of impaired consciousness (64%), shorter time to diagnosis, the presence of multiple abscesses (70%), microangiopathy (52%), detection of serum galactomannan (69%) and Aspergillus PCR (68%), and higher six-week mortality (54%). By contrast, contiguous dissemination from the paranasal sinuses (n = 31) was associated with a higher frequency of cranial nerve palsy (65%), evidence of meningitis on cerebral imaging (83%), macrovascular lesions (61%), delayed diagnosis, and lower six-week mortality (30%). In multivariate analysis and in a risk prediction model, haematogenous dissemination, hematological malignancy and the detection of serum galactomannan were associated with higher six-week mortality. CONCLUSION: Distinguishing between hematogenous and contiguous dissemination patterns appears to be critical in the workup for CA, as they are associated with significant differences in clinical presentation and outcome.

Antifungal susceptibility testing practices in mycology laboratories in France, 2018.

A survey of mycology laboratories for antifungal susceptibility testing (AFST) was undertaken in France in 2018, to better understand the difference in practices between the participating centers and to identify the difficulties they may encounter as well as eventual gaps with published standards and guidelines. The survey captured information from 45 mycology laboratories in France on how they perform AFST (number of strains tested, preferred method, technical and quality aspects, interpretation of the MIC values, reading and interpretation difficulties). Results indicated that 86% of respondents used Etest as AFST method, with a combination of one to seven antifungal agents tested. Most of the participating laboratories used similar technical parameters to perform their AFST method and a large majority used, as recommended, internal and external quality assessments. Almost all the participating mycology laboratories (98%) reported difficulties to interpret the MIC values, especially when no clinical breakpoints are available. The survey highlighted that the current AFST practices in France need homogenization, particularly for MIC reading and interpretation.

Comparison of matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) systems for the identification of moulds in the routine microbiology laboratory.

OBJECTIVES: The purpose of this study was to compare the efficiency of mould identification of two matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) systems - Vitek MS (VMS) and Microflex LT (MLT) - and the MSI application. METHODS: Moulds were collected retrospectively and prospectively to display epidemiological diversity of a microbiology laboratory. All of them were identified via sequencing. Strains were then identified using the VMS v3.0, the MLT, and the MSI software applied on MLT spectra. Rates of correct identifications to the species, to the complex, and to the genus level were compared with the molecular reference standard. RESULTS: A total of 102 isolates were collected. The rate of correct identification to the species level with the MLT was 42.2% (43/102) with a threshold of 1.7 (vs. 16.7% (17/102) with a threshold of 2.0, p < 0.05). The VMS performed better than the MLT with a threshold of 1.7 for species (49.0% (50/102), p 0.33) and complex level identifications (71.6% (73/102) vs. 54.9% (56/102), p < 0.05). However the highest performances were observed when the MLT spectra were analysed via the Mass Spectrometry Identification (MSI) software reaching 90.2% (92/102) of correct identification to the species, 92.2% (94/102) to the species complex and 94.1% (96/102) to the genus level. CONCLUSIONS: The VMS performed better than the MLT for mould identification. However, it remains of utmost importance to expand commercial databases, as performances of the MLT highly improved when using the MSI software and its extended database, reaching far above the VMS system. Thus the VMS could benefit from the use of this online tool.

Multicentre study to determine the Etest epidemiological cut-off values of antifungal drugs in Candida spp. and Aspergillus fumigatus species complex.

OBJECTIVES: To determine the Etest-based epidemiological cut-off values (ECVs) for antifungal agents against the most frequent yeast and Aspergillus fumigatus species isolated in 12 French hospitals. METHODS: For each antifungal agent, the Etest MICs in yeast and A. fumigatus isolates from 12 French laboratories were retrospectively collected from 2004 to 2018. The ECVs were then calculated using the iterative statistical method with a 97.5% cut-off. RESULTS: Forty-eight Etest ECVs were determined for amphotericin B, caspofungin, micafungin, anidulafungin, fluconazole, voriconazole, posaconazole and itraconazole, after pooling and analysing the MICs of 9654 Candida albicans, 2939 Candida glabrata SC, 1458 Candida parapsilosis SC, 1148 Candida tropicalis, 575 Candida krusei, 518 Candida kefyr, 241 Candida lusitaniae, 131 Candida guilliermondii and 1526 Aspergillus fumigatus species complex isolates. These ECVs were 100% concordant (identical or within one two-fold dilution) with the previously reported Etest-based ECVs (when available), and they were concordant in 76.1% of cases with the Clinical and Laboratory Standards Institute ECVs and in 81.6% of cases with the European Committee on Antimicrobial Susceptibility Testing ECVs. CONCLUSIONS: On the basis of these and other previous results, we recommend the determination of method-dependent ECVs. Etest ECVs should not be used instead of breakpoints, but may be useful to identify non-wild-type isolates with potential resistance to antifungal agents, and to indicate that an isolate may not respond as expected to the standard treatment.

Free ceramides of Echinococcus multilocularis metacestodes.

Free ceramides were isolated and purified from the metacestodes of Echinococcus multilocularis. Two different fractions were obtained by preparative thin-layer chromatography. Their structure was determined by gas chromatography and electron impact mass spectrometry of trimethylsilylated derivatives. The ceramide with the higher thin-layer chromatographic migration rate contained exclusively erythro-sphinganine associated with saturated C16, C18 and very-long-chain fatty acids (up to C30) and unsaturated C24 fatty acid. The second ceramide contained 90.3% sphingosine and 9.7% sphinganine associated with saturated C16 and C24 and unsaturated C18 and C24 fatty acids. These findings were discussed with regard to the structure and metabolic pathway of neutral and acid glycosphingolipids found in the metacestodes.

Gangliosides of Echinococcus multilocularis metacestodes.

Gangliosides, glycosphingolipids with sialic acid, were found in metacestodes of Echinococcus multilocularis in low quantities. All gangliosides were resolved after preparative high-performance thin layer chromatography into four fractions. Cholera toxin was specifically bound to the major ganglioside, allowing the identification of it as a GM1. Precise structure of the four fractions was determined by sequential degradation by exoglycosidases, gas chromatography, electron impact mass spectrometry and liquid secondary ion-mass spectrometry. Beside GM1, the other fractions were GM3, GD1a and, at a lesser percentage, GM2, all belonging to the same a-ganglio-series. The ceramide part of these parasite gangliosides contained sphingosine associated to unsaturated n24, saturated n24 and n16 fatty acids.

Properties of uridine diphosphate glucose pyrophosphorylase from Golgi apparatus of liver.

Golgi apparatus isolated from cat liver contained UDPglucose pyrophosphorylase (UTP:alpha-D-glucose-1-phosphate uridylyltransferase, EC 2.7.7.9) activity. The results of washing suggested that pyrophosphorylase was bound firmly to Golgi membranes. Moreover, the enzyme was activated by Triton X-100 in the same extent as galactosyltransferase, a typical Golgi apparatus enzyme. Two-substrate kinetic studies were performed with the enzymes from cytosol and Golgi fractions. The soluble enzyme showed an apparent 2.5-fold greater activity for the glucose 1-phosphate than for UTP, while pyrophosphorylase of Golgi apparatus had the same affinity for the two substrates. A random mechanism was observed with a direct dependence of apparent Michaelis constant values on the concentration of second substrate for soluble enzyme. In contrast, with Golgi enzyme one ligand had no effect on the binding of the other.

Evidence for coupling between transport of UDP-glucose and its synthesis by membrane-bound pyrophosphorylase in Golgi apparatus of cat liver.

Incubation of sealed vesicles of cat-liver Golgi apparatus with UDP[14C]glucose showed that the vesicles accumulated radioactivity. After Triton X-100 treatment or sonication of washed vesicles, soluble radiolabeled species were released and identified by paper chromatography as UDP[14C]glucose, [14C]glucose 1-phosphate and free glucose. In the incubation medium, UDPglucose was effectively protected by addition of dimercaptopropanol and UTP. Presence of glucose 1-phosphate and glucose within the vesicles most probably arose from luminal pyrophosphatase and phosphatase. A portion of the [14C]glucose moiety became covalently linked to endogenous acceptors. Uptake of UDPglucose was saturable and dependent on time and on the concentration of sugar nucleotide. Together, these results were consistent with a transport system for UDPglucose in Golgi vesicles. Furthermore, penetration rate was considerably higher with UDPglucose synthetized in situ from glucose 1-phosphate by membrane-bound pyrophosphorylase than from added UDPglucose: Vmax values were respectively 10 and 2 pmol/15 min per mg protein. This result allows the conclusion that a coupling between translocase and synthetase is involved in UDPglucose transport through Golgi apparatus membranes. The mechanism of this 'kinetic advantage' is discussed.

Plasma itraconazole concentrations in neutropenic patients after repeated high-dose treatment.

Two different treatments with repeated oral high doses of itraconazole were tested for 10 days in 20 neutropenic patients, 10 receiving 400 mg per day and 10 receiving 600 mg per day. In each group 5 patients were treated for acute leukaemia and 5 patients were recipients of autologous bone-marrow transplantation (ABMT). Itraconazole plasma concentrations were assayed by high-performance liquid chromatography. Statistical analysis disclosed a significant interaction between the dispensed dose and the patient types. The difference between the two doses of itraconazole was greater in the ABMT than in the leukaemia patients. After 10 days at 600 mg per day all the ABMT patients had an itraconazole plasma concentration higher than 250 micrograms/l. Therefore, 600 mg per day seems more efficient to obtain a therapeutic level of itraconazole in ABMT patients but this needs to be confirmed for all the neutropenic patients.

Glycosphingolipids of Echinococcus multilocularis metacestodes.

Neutral and acid glycosphingolipids of Echinococcus multilocularis metacestodes that were obtained after intraperitoneal infection of Meriones unguiculatus have been analyzed by thin layer chromatography. Neutral and acid glycosphingolipids accounted for 95% and 5% of total glycosphingolipids, respectively. 12 different fractions were observed in the neutral glycosphingolipids extracts of the parasite. The most important was a monohexosylceramide fraction accounting for 56.4% of neutral glycosphingolipids. 9 different fractions were detected in gangliosides (acid glycosphingolipids). The fact that these glycosphingolipids were specific to the parasite was established by the analysis of different cell populations of the host. Glycosphingolipids were purified from control and parasite-infected gerbil blood cells as well as from peritoneal exudate cells of healthy gerbils after a non-specific immunostimulation. The chromatograms obtained with these extracts were totally different from the parasite. In addition, parasitosis was found to have no effect on the host blood cell glycosphingolipids.

Analysis of the monohexosylceramide fraction of Echinococcus multilocularis metacestodes.

Monohexosylceramides of Echinococcus multilocularis metacestodes have been isolated and analyzed by thin-layer chromatography, gas-liquid chromatography and mass spectrometry. 90.9% of the parasite fraction was galactosylceramide; glucosylceramide was present at only 9.1%. The most important fatty acids were normal C16:0 and C26:0 fatty acids. The hydroxylated fatty acids of the ceramide part constituted 20.1% of the total, their major constituents were C18:0 and C26:0. The sphinganine accounted for 70.4% of long-chain bases, phytosphingosine and sphingosine were also detected. The importance of the long chain fatty acids and the presence of sphinganine in the monohexosylceramide fraction were discussed.

A comparative study of UTP-D-glucose-1-phosphate uridylyl transferase in the cysts of Echinococcus multilocularis and the livers of infected and control Meriones unguiculatus.

Kinetic and physical parameters of UDP-glucose pyrophosphorylase were determined in Meriones unguiculatus infected with Echinococcus multilocularis metacestodes (cestoda). Studies were carried out on parasite cysts, and on livers from control and infected animals after purification of the enzyme by affinity chromatography on UTP-agarose. The enzyme from infected and control livers had km values for UTP of 0.01 mM and 0.5 mM, respectively; for glucose-1-phosphate values were 0.46 mM and 0.07 mM, respectively. On the other hand the enzyme from cysts was found to have a higher Km for UTP (1 mM) and for glucose-1-phosphate (1.5 mM) than from infected or non-infected livers. Physical characteristics (pI = 6 and Mr = 160,000) of UDP-glucopyrophosphorylases were the same in controls and infected host livers but were different from the cyst enzyme (pI = 7 and Mr = 251,000). These results provide evidence for the existence of significant differences between parasitic and host enzymes, which could possibly be exploited in chemotherapy.

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.

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.