ABSTRACT
OBJECTIVES: Cytomegalovirus (CMV) is frequently detected in lung and/or blood samples of patients with Pneumocystis jirovecii pneumonia (PJP), although this co-detection is not precisely understood. We aimed to determine whether PJP was more severe in case of CMV detection. METHODS: We retrospectively included all patients with a diagnosis of PJP between 2009 and 2020 in our centre and with a measure of CMV viral load in blood and/or bronchoalveolar lavage (BAL). PJP severity was assessed by the requirement for intensive care unit (ICU) admission. RESULTS: The median age of the 249 patients was 63 [IQR: 53-73] years. The main conditions were haematological malignancies (44.2%), solid organ transplantations (16.5%), and solid organ cancers (8.8%). Overall, 36.5% patients were admitted to ICU. CMV was detected in BAL in 57/227 patients; the 37 patients with viral load ≥3 log copies/mL were more frequently admitted to ICU (78.4% vs 28.4%, p<0.001). CMV was also detected in blood in 57/194 patients; the 48 patients with viral load ≥3 log copies/mL were more frequently admitted to ICU (68.7% vs 29.4%, p<0.001). ICU admission rate was found to increase with each log of BAL CMV viral load and each log of blood CMV viral load. CONCLUSIONS: PJP is more severe in the case of concomitant CMV detection. This may reflect either the deleterious role of CMV itself, which may require antiviral therapy, or the fact that patients with CMV reactivation are even more immunocompromised.
Subject(s)
Acquired Immunodeficiency Syndrome , Cytomegalovirus Infections , Pneumonia, Pneumocystis , Humans , Middle Aged , Aged , Pneumonia, Pneumocystis/diagnosis , Cytomegalovirus , Retrospective Studies , Intensive Care Units , Cytomegalovirus Infections/complications , Cytomegalovirus Infections/diagnosisSubject(s)
Neoplasms , Schistosomiasis haematobia , Schistosomiasis mansoni , Schistosomiasis , Animals , Humans , Schistosoma haematobium , Schistosoma mansoniABSTRACT
OBJECTIVES: To determine the epidemiological cut-off values (ECVs) of ten antifungal agents in a wide range of yeasts and Aspergillus spp. using gradient concentration strips. METHODS: The minimum inhibitory concentrations for amphotericin B, anidulafungin, caspofungin, micafungin, flucytosine, fluconazole, itraconazole, isavuconazole, posaconazole, and voriconazole, determined with gradient concentration strips at 35 French microbiology laboratories between 2002 and 2020, were retrospectively collected. Then, the ECVs were calculated using the iterative method and a cut-off value of 97.5%. RESULTS: Minimum inhibitory concentrations were available for 17 653 clinical isolates. In total, 48 ECVs (including 32 new ECVs) were determined: 29 ECVs for frequent yeast species (e.g. Candida albicans and itraconazole/flucytosine, and Candida glabrata species complex [SC] and flucytosine) and rare yeast species (e.g. Candida dubliniensis, Candida inconspicua, Saccharomyces cerevisiae, and Cryptococcus neoformans) and 19 ECVs for Aspergillusflavus SC, Aspergillusfumigatus SC, Aspergillusnidulans SC, Aspergillusniger SC, and Aspergillusterreus SC. CONCLUSIONS: These ECVs can be added to the already available gradient concentration strip-specific ECVs to facilitate minimum inhibitory concentration interpretation and streamline the identification of nonwild type isolates.
Subject(s)
Antifungal Agents , Itraconazole , Humans , Antifungal Agents/pharmacology , Itraconazole/pharmacology , Flucytosine , Saccharomyces cerevisiae , Retrospective Studies , Phylogeny , Fluconazole/pharmacology , Aspergillus , Microbial Sensitivity Tests , Drug Resistance, FungalABSTRACT
Chromoblastomycosis and sporotrichosis are the two main implantation mycoses that are now recognized as fungal neglected tropical diseases (NTDs). Their laboratory diagnosis mainly relies on direct microscopy, histopathology, and identification of the fungus by culture. However, to be appropriately used, these techniques require mycological expertise that is not widely available and may be absent in peripheral health care facilities in endemic areas. In addition, they lack sensitivity and specificity, and the culture for isolation and identification can have a long time-to-results period. Molecular methods, including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), have been developed in well-equipped reference laboratories. They greatly improve the rapidity and accuracy of diagnosis; in particular, for species identification. Recently, PCR and sequencing have paved the way for more user-friendly point-of-care tests, such as those based on LAMP or RCA technologies, which can be used in basic healthcare settings and even in field consultations.
ABSTRACT
FR235222 is a natural tetra-cyclopeptide with a strong inhibition effect on histone deacetylases, effective on mammalian cells as well as on intracellular apicomplexan parasites, such as Toxoplasma gondii, in the tachyzoite and bradyzoite stages. This molecule is characterized by two parts: the zinc-binding group, responsible for the binding to the histone deacetylase, and the cyclic tetrapeptide moiety, which plays a crucial role in cell permeability. Recently, we have shown that the cyclic tetrapeptide coupled with a fluorescent diethyl-amino-coumarin was able to maintain properties of cellular penetration on human cells. Here, we show that this property can be extended to the crossing of the Toxoplasma gondii cystic cell wall and the cell membrane of the parasite in its bradyzoite form, while maintaining a high efficacy as a histone deacetylase inhibitor. The investigation by molecular modeling allows a better understanding of the penetration mechanism.
Subject(s)
Coumarins/pharmacology , Fluorescent Dyes/pharmacology , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylases/metabolism , Peptides, Cyclic/pharmacology , Coumarins/chemistry , Fluorescent Dyes/chemistry , Histone Deacetylase Inhibitors/chemistry , Models, Molecular , Peptides, Cyclic/chemistry , Toxoplasma/cytology , Toxoplasma/enzymologyABSTRACT
Systemic antifungal agents are increasingly used for prevention or treatment of invasive fungal infections, whose prognosis remains poor. At the same time, emergence of resistant or even multi-resistant strains is of concern as the antifungal arsenal is limited. Antifungal susceptibility testing (AFST) is therefore of key importance for patient management and antifungal stewardship. Current AFST methods, including reference and commercial types, are based on growth inhibition in the presence of an antifungal, in liquid or solid media. They usually enable Minimal Inhibitory Concentrations (MIC) to be determined with direct clinical application. However, they are limited by a high turnaround time (TAT). Several innovative methods are currently under development to improve AFST. Techniques based on MALDI-TOF are promising with short TAT, but still need extensive clinical validation. Flow cytometry and computed imaging techniques detecting cellular responses to antifungal stress other than growth inhibition are also of interest. Finally, molecular detection of mutations associated with antifungal resistance is an intriguing alternative to standard AFST, already used in routine microbiology labs for detection of azole resistance in Aspergillus and even directly from samples. It is still restricted to known mutations. The development of Next Generation Sequencing (NGS) and whole-genome approaches may overcome this limitation in the near future. While promising approaches are under development, they are not perfect and the ideal AFST technique (user-friendly, reproducible, low-cost, fast and accurate) still needs to be set up routinely in clinical laboratories.
Subject(s)
Antifungal Agents , Drug Resistance, Fungal , Antifungal Agents/pharmacology , Aspergillus , Humans , Microbial Sensitivity TestsABSTRACT
Objectives: To evaluate the analytical and clinical performance of a prototype of a VIDAS® Galactomannan (GM) unitary test (bioMérieux, Marcy l'Etoile, France) and compare to that of the Platelia™ Aspergillus Ag assay (Bio-Rad, CA, USA). Methods: Repeatability, reproducibility, and freeze-thaw stability of VIDAS®GM were evaluated. Sera from patients at risk of IA were concurrently tested with both the VIDAS®GM and Platelia™ Aspergillus Ag assays. Correlations between the two assays were assessed by Passing Bablok (PB) regression and performance by ROC analysis. Results: The correlations between the VIDAS®GM indexes after one and two cycles of freezing/thawing were r=1.00 and r=0.989, respectively. The coefficients of variation for negative, low-positive, and positive sera were 13%, 6%, and 5% for repeatability and 14.4%, 7.2%, and 5.5% for reproducibility. Overall, 126 sera were tested with both assays (44 fresh and 82 frozen). The correlation between VIDAS®GM and Platelia™ Aspergillus Ag was r=0.798. The areas under the curve of the ROC analyses were 0.892 and 0.894, for VIDAS®GM and Platelia™ Aspergillus Ag, respectively. Conclusions: This new VIDAS®GM prototype assay showed adequate analytical and clinical performance and a good correlation with that of Platelia™ Aspergillus Ag with 126 sera, although these results need to be confirmed in a larger prospective and multicentric study. As for the other VIDAS® assays, VIDAS®GM is a single-sample automated test using a solid reagent strip and receptacle. It is easy to use and suitable for rapid on-demand test results.
Subject(s)
Aspergillosis , Aspergillus , Aspergillosis/diagnosis , France , Galactose/analogs & derivatives , Humans , Mannans , Prospective Studies , Reproducibility of Results , Sensitivity and Specificity , TechnologyABSTRACT
The implementation of MALDI-TOF MS in medical microbiology laboratories has revolutionized practices and significantly reduced turnaround times of identification processes. However, although bacteriology quickly benefited from the contributions of this technique, adjustments were necessary to accommodate the specific characteristics of fungi. MALDI-TOF MS is now an indispensable tool in clinical mycology laboratories, both for the identification of yeasts and filamentous fungi, and other innovative uses are gradually emerging. Based on the practical experience of our medical mycology laboratory, this review will present the current uses of MALDI-TOF MS and the adaptations we implemented, to allow their practical execution in a daily routine. We will also introduce some less mainstream applications, like those for fungemia, or even still under development, as is the case for the determination of sensitivity to antifungal agents or typing methods.
ABSTRACT
BACKGROUND: We aimed to assess the prognostic value of repeated measurements of serum (1-3)-ß-D-glucan (BDG), mannan-antigen (mannan-Ag), and antimannan antibodies (antimannan-Ab) for the occurrence of invasive candidiasis (IC) in a high-risk nonimmunocompromised population. METHODS: This was a preplanned ancillary analysis of the EMPIRICUS Randomized Clinical Trial, including nonimmunocompromised critically ill patients with intensive care unit-acquired sepsis, multiple Candida colonization, and multiple organ failure who were exposed to broad-spectrum antibacterial agents. BDG (>80 and >250 pg/mL), mannan-Ag (>125 pg/mL), and antimannan-Ab (>10 AU) were collected repeatedly. We used cause-specific hazard models. Biomarkers were assessed at baseline in the whole cohort (cohort 1). Baseline covariates and/or repeated measurements and/or increased biomarkers were then studied in the subgroup of patients who were still alive at day 3 and free of IC (cohort 2). RESULTS: Two hundred thirty-four patients were included, and 215 were still alive and free of IC at day 3. IC developed in 27 patients (11.5%), and day 28 mortality was 29.1%. Finally, BDGâ >80 pg/mL at inclusion was associated with an increased risk of IC (CSHR[IC], 4.67; 95% CI, 1.61-13.5) but not death (CSHR[death], 1.20; 95% CI, 0.71-2.02). CONCLUSIONS: Among high-risk patients, a first measurement of BDG >80 pg/mL was strongly associated with the occurrence of IC. Neither a cutoff of 250 pg/mL nor repeated measurements of fungal biomarkers seemed to be useful to predict the occurrence of IC. The cumulative risk of IC in the placebo group if BDGâ >80 pg/mL was 25.39%, which calls into question the efficacy of empirical therapy in this subgroup.
ABSTRACT
In the non-AIDS group, several underlying conditions and immune defects could lead to different PCP presentations. This study compared PCP presentation and outcome according to the underlying disease. A secondary analysis of a previously published prospective observational study including 544 PCP patients was done. Only non-AIDS patients were included. Underlying disease was defined as chronic lymphocytic leukemia (CLL), organ transplantation, solid cancer, allogeneic hematopoietic stem cell transplant (AHSCT), other hematological diseases, and immunosuppressive treatment. Clinical characteristics and outcomes were compared between groups. Multiple correspondent analyses compared clinical characteristics at diagnosis. Day 30 mortality was analyzed. Three hundred and twenty-one patients were included in the study. The underlying diseases were hematological malignancy (n = 75), AHSCT (n = 14), CLL (n = 19), solid organ transplant (n = 94), solid tumor (n = 39), and immunosuppressive treatment (n = 57). Compared with other underlying diseases, PCP related to CLL was closer to PCP related to AIDS presentation (long duration of symptoms before diagnosis, high level of dyspnea, and low oxygen saturation at diagnosis). Day 30 mortality was associated with underlying disease, oxygen flow, and shock at ICU admission. PCP presentations may vary according to the underlying reason for immunosuppression. Response to treatment and adjuvant steroid therapy should be analyzed regarding this result.
Subject(s)
Pneumonia, Pneumocystis/complications , Respiratory Insufficiency/etiology , Respiratory Insufficiency/mortality , Acute Disease , Aged , Female , Hematologic Diseases/complications , Humans , Leukemia, Lymphoid/complications , Male , Middle Aged , Pneumonia, Pneumocystis/diagnosis , Prospective StudiesABSTRACT
During bloodstream infections, rapid adaptation of empirical treatment according to the microorganism identified is essential to decrease mortality. The aim of the present study was to assess the microbiological performances of a new rapid version of the Sepsityper® kit (Bruker Daltonics) allowing identification of bacteria and yeast by MALDI-TOF mass spectrometry directly from positive blood cultures in 10 min and of the specific MBT-Sepsityper module for spectra analysis, designed to increase identification performance. Identification rates were determined prospectively on 350 bacterial and 29 fungal positive blood cultures, and compared to conventional diagnostic method. Our rapid diagnosis strategy (Rapid Sepsityper® protocol: one spot with and one without formic acid extraction step) combined to MBT-Sepsityper module provided 65.4%, 78.9% and 62% reliable identification to the species level of monomicrobial positive blood cultures growing respectively Gram-positive, Gram-negative bacteria or yeast. Importantly, identification rates of Gram-positive bacteria were higher in anaerobic than in aerobic bottles (77.8% vs 22.2%; p = 0.004), if formic acid extraction step was performed (60.8% vs 39.2%; p = 1.8e-6) and if specific MBT-Sepsityper module was used (76.2% vs 61.9%, p = 0.041) while no significant differences were observed for Gram-negative bacteria. For yeasts identification, formic acid extraction step improved rapid identification rate by 37.9% while the specific MBT-Sepsityper module increased overall performances by 38%, providing up to 89.7% reliable identification if associated with the standard Sepsityper® protocol. These performances, associated with a reduce turnaround time, may help to implement a rapid identification strategy of bloodstream infections in the routine workflow of microbiology laboratories.
Subject(s)
Bacteremia/diagnosis , Bacteria/isolation & purification , Bacterial Typing Techniques/methods , Fungemia/diagnosis , Mycological Typing Techniques/methods , Tandem Mass Spectrometry/methods , Yeasts/isolation & purification , Bacteremia/microbiology , Bacteria/chemistry , Blood/microbiology , Blood Culture , Fungemia/microbiology , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Yeasts/chemistryABSTRACT
Molecular rapid diagnostic assays associated with antimicrobial stewardship have proven effective for the early adaptation of empiric therapy in bloodstream infections. The ePlex® BCID (GenMark Diagnostics) Panels allow identification of 56 bacteria and fungi and 10 resistance genes in 90 min directly from positive blood cultures. We prospectively evaluated 187 sepsis episodes at Grenoble University Hospital and retrospectively analyzed the cases to measure the potential clinical impact of the ePlex BCID results. Identification of all pathogens was obtained for 164/187 (88%) bloodstream infections with 100% detection of antimicrobial resistance genes (17 blaCTX-M , 1 vanA, and 17 mecA genes). Only 15/209 (7%) strains were not covered by the panels. Sensitivity for detection of micro-organisms targeted by the RUO BCID-GP, BCID-GN, and BCID-FP Panels was respectively 84/84 (100%), 103/107 (96%), and 14/14 (100%). Interestingly, accurate identification of all pathogens was achieved in 15/17 (88%) polymicrobial samples. Retrospective analysis of medical records showed that a modification of antimicrobial treatment would have been done in 45% of the patients. Treatment modifications would have been an optimization of empiric therapy, a de-escalation or an escalation in respectively 16, 17, and 11% of the patients. Moreover, 11% of the samples were classified as contaminants or not clinically relevant and would have led to early de-escalation or withdrawal of any antibiotic. Detection of resistance genes in addition to identification alone increased escalation rate from 4 to 11% of the patients. Absence of the ePlex result was considered a lost opportunity for therapy modiï¬cation in 28% of patients.
Subject(s)
Bacteremia , Fungemia , Bacteremia/diagnosis , Blood Culture , Fungemia/diagnosis , Fungi/genetics , Humans , Retrospective StudiesABSTRACT
OBJECTIVE: To describe the clinical aspects of chromoblastomycosis (CBM) presented by patients who had received incomplete antifungal treatment before consultation. METHODS: A prospective study of patients with clinically suspected CBM was performed between 2013 and 2018 in the Department of Dermatology at the University Hospital Antananarivo, and during consultation campaigns. RESULTS: Patients develop CBM over a period of more than 10 years, and many will have already received antifungals prescribed by general practitioners before consulting with a dermatologist. Such treatment obviously modifies the clinical presentation. From the 63 CBM patients in this large study, we describe 12 patients who received oral antifungals (terbinafine, griseofulvine, itraconazole, fluconazole) before consultation. The most frequent clinical aspect presented by these patients was cicatricial lesions, which are characteristically smooth and non-elevated, and enlarge by peripheral extension, with atrophic scarring at the center. CONCLUSION: Our study is the first to show that cicatricial lesions are a clinical aspect presented by CBM patients who received antifungals before presentation.
Subject(s)
Antifungal Agents/therapeutic use , Chromoblastomycosis/drug therapy , Adult , Aged , Chromoblastomycosis/microbiology , Chromoblastomycosis/pathology , Female , Humans , Itraconazole/therapeutic use , Madagascar , Male , Middle Aged , Prospective Studies , Terbinafine/therapeutic useABSTRACT
The reported number of cases of Acanthamoeba amebic keratitis (AK) is continually increasing. Molecular diagnosis has become the first choice of ophthalmologists for identifying and confirming this clinically problematic diagnosis. However, in-house molecular diagnostic procedures are time-consuming and may not be compatible with the urgency of the situation. In this study, a previous in-house AK-PCR technique was adapted for use on BD MAX (Becton Dickinson, Heidelberg, Germany), a fully integrated, automated platform for molecular biology, for the rapid routine diagnosis of AK. Different protocols were compared to optimize DNA extraction from Acanthamoeba cysts. The analytical parameters of the AK-BD MAX PCR were evaluated. Thirty-two samples were simultaneously tested with AK-BD MAX PCR and the original AK-PCR from which it was developed. A thermal-shock pretreatment protocol was validated. The analytical parameters obtained with BD MAX were similar to those obtained with the previous in-house AK-PCR method. The performance of AK-BD MAX PCR was then assessed for routine testing on 40 clinical samples, mostly corneal scrapings. Frozen, ready-to-use, in-house PCR premixes were stable over 8 months. Overall, 34 of the 40 clinical samples (85%) were considered to be true negatives; 4 (10%), probable AK; and 2 (5%), possible AK. This newly developed AK-BD MAX PCR is reliable, rapid, and efficient, and should facilitate Acanthamoeba keratitis diagnosis.
Subject(s)
Acanthamoeba Keratitis/diagnosis , Acanthamoeba/genetics , Molecular Diagnostic Techniques/methods , Multiplex Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction/methods , Acanthamoeba Keratitis/parasitology , Acanthamoeba Keratitis/pathology , Biopsy , Cornea/pathology , DNA, Protozoan/genetics , DNA, Protozoan/isolation & purification , Diagnostic Tests, Routine/methods , Genotype , Humans , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Chromoblastomycosis is an implantation fungal infection. Twenty years ago, Madagascar was recognized as the leading focus of this disease. We recruited patients in Madagascar who had chronic subcutaneous lesions suggestive of dermatomycosis during March 2013-June 2017. Chromoblastomycosis was diagnosed in 50 (33.8%) of 148 patients. The highest prevalence was in northeastern (1.47 cases/100,000 persons) and southern (0.8 cases/100,000 persons) Madagascar. Patients with chromoblastomycosis were older (47.9 years) than those without (37.5 years) (p = 0.0005). Chromoblastomycosis was 3 times more likely to consist of leg lesions (p = 0.003). Molecular analysis identified Fonsecaea nubica in 23 cases and Cladophialophora carrionii in 7 cases. Of 27 patients who underwent follow-up testing, none were completely cured. We highlight the persistence of a high level of chromoblastomycosis endemicity, which was even greater at some locations than 20 years ago. We used molecular tools to identify the Fonsecaea sp. strains isolated from patients as F. nubica.
Subject(s)
Ascomycota , Chromoblastomycosis , Antifungal Agents/therapeutic use , Ascomycota/genetics , Chromoblastomycosis/diagnosis , Chromoblastomycosis/drug therapy , Chromoblastomycosis/epidemiology , Fonsecaea , Humans , Madagascar/epidemiologyABSTRACT
MALDI-TOF mass spectrometry (MS) identification of pathogenic filamentous fungi is often impaired by difficulties in harvesting hyphae embedded in the medium and long extraction protocols. The ID Fungi Plate (IDFP) is a novel culture method developed to address such difficulties and improve the identification of filamentous fungi by MALDI-TOF MS. We cultured 64 strains and 11 clinical samples on IDFP, Sabouraud agar-chloramphenicol (SAB), and ChromID Candida agar (CAN2). We then compared the three media for growth, ease of harvest, amount of material picked, and MALDI-TOF identification scores after either rapid direct transfer (DT) or a long ethanol-acetonitrile (EA) extraction protocol. Antifungal susceptibility testing and microscopic morphology after subculture on SAB and IDFP were also compared for ten molds. Growth rates and morphological aspects were similar for the three media. With IDFP, harvesting of fungal material for the extraction procedure was rapid and easy in 92.4% of cases, whereas it was tedious on SAB or CAN2 in 65.2% and 80.3% of cases, respectively. The proportion of scores above 1.7 (defined as acceptable identification) were comparable for both extraction protocols using IDFP (P = 0.256). Moreover, rates of acceptable identification after DT performed on IDFP (93.9%) were significantly higher than those obtained after EA extraction with SAB (69.7%) or CAN2 (71.2%) (P = <0.001 and P = 0.001, respectively). Morphological aspects and antifungal susceptibility testing were similar between IDFP and SAB. IDFP is a culture plate that facilitates and improves the identification of filamentous fungi, allowing accurate routine identification of molds with MALDI-TOF-MS using a rapid-extraction protocol.
Subject(s)
Ascomycota , Fungi , Candida , Culture Media , Diagnostic Tests, Routine , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
Therapeutic drug monitoring (TDM) of antifungal triazole was recommended, except for isavuconazole (ISA) whose target trough concentrations (Cmin ) need to be specified. Concerning posaconazole (POS), tablet formulation results in higher exposure but no upper Cmin threshold has been yet proposed. We aimed to investigate the pharmacokinetic-pharmacodynamic relationship of POS and ISA, using a bioassay approach as surrogate marker of antifungal activity, in order to refine the therapeutic Cmin of both antifungals. A bioassay using a cellulose disk diffusion method was performed to determine the growth inhibition zone (GIZ) of POS and ISA on Aspergillus fumigatus and Candida parapsilosis (ISA only). GIZs of plasma from patients undergoing TDM for POS (n = 136) or ISA (n = 40) were determined. GIZs of plasma patients and antifungal Cmin were highly correlated for ISA (A. fumigatus: ρ = 0.942, P < 0.0001; C. parapsilosis: ρ = 0.949, P < 0.0001) and POS (ρ = 0.922, P < 0.0001), and these relationships were represented with a Michaelis-Menten model. Based on this modeling, the recommended thresholds of 0.7, 1, and 1.25 mg/L for the POS Cmin corresponded to 50.1, 55.2, and 59.1% of the maximal GIZ, respectively. We propose an upper threshold of 4.8 mg/L for the POS Cmin and a lower threshold of 2.0 mg/L for the Cmin of ISA, as they respectively corresponded to concentrations leading to 90% and 50% of the maximal GIZ on A. fumigatus. The determination of antifungal activity using this bioassay allowed refining target Cmin of POS and ISA, especially the upper threshold of POS (4.8 mg/L) and the lower threshold of ISA (2.0 mg/L).
Subject(s)
Antifungal Agents/pharmacokinetics , Drug Monitoring/methods , Nitriles/pharmacokinetics , Pyridines/pharmacokinetics , Triazoles/pharmacokinetics , Adult , Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Biological Assay/methods , Candida parapsilosis/drug effects , Disk Diffusion Antimicrobial Tests , Female , Humans , Male , Middle Aged , Nitriles/pharmacology , Pyridines/pharmacology , Triazoles/pharmacologyABSTRACT
The antifungal susceptibility tests used in clinical laboratories have several limitations. We developed a new test, SensiFONG, based on the detection of chitin levels after exposure to antifungal drugs. The optimal culture conditions were 30°C for 6 h for yeast strains and 26°C for 16 h for molds. The strains were exposed to a range of echinocandin or azole concentrations. Chitin was stained with calcofluor white. The percentage of fungal cells with high chitin levels was determined with an automatic epifluorescence microscope. The SensiFONG results were compared to those with the EUCAST method. Image acquisition and analysis were performed with ScanR software. Fifty-nine strains (28 Candida albicans, 17 Candida glabrata, and 14 Aspergillus fumigatus) were analyzed. Thresholds for the classification of strains as resistant or susceptible were determined for each fungal species. The strains displaying an increase in chitin content of ≥32% for C. albicans, ≥6% for C. glabrata, and ≥17% for A. fumigatus were considered susceptible. The application of these thresholds to all 59 strains resulted in a sensitivity of 0.87, 0.93, and 1.00 and a specificity of 0.93, 0.84, and 0.82 for C. albicans, C. glabrata, and A. fumigatus, respectively. The correlation between the results obtained in the SensiFONG and EUCAST assays was excellent. We developed a new test, SensiFONG, based on a new concept. While current assays assess growth inhibition, our test detects changes in chitin levels after exposure to antifungal drugs. Here, we present preliminary results and we propose a proof of concept of this methodology.
Subject(s)
Antifungal Agents/pharmacology , Chitin/metabolism , Fungi/drug effects , Fungi/metabolism , Image Cytometry/methods , Microbial Sensitivity Tests/methods , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/metabolism , Candida/drug effects , Candida/metabolism , Candida albicans/drug effects , Candida albicans/metabolism , Candida glabrata/drug effects , Candida glabrata/metabolism , Cell Wall/drug effects , Cell Wall/metabolism , Drug Resistance, Fungal , Humans , Image Cytometry/statistics & numerical data , Microbial Sensitivity Tests/statistics & numerical data , Proof of Concept Study , Reproducibility of ResultsABSTRACT
Sporotrichosis is a saprozoonotic fungal infection found mostly in tropical and subtropical areas. Few case reports in Madagascar have been published. To document sporotrichosis epidemiology in Madagascar, we conducted a cross-sectional study. During March 2013-June 2017, we recruited from select hospitals in Madagascar patients with chronic cutaneous lesions suggestive of dermatomycosis. Sporotrichosis was diagnosed for 63 (42.5%) of 148 patients. All but 1 patient came from the central highlands, where the prevalence was 0.21 cases/100,000 inhabitants. Frequency was high (64.7%) among patients <18 years of age. Sporotrichosis was diagnosed for 73.8% of patients with arm lesions, 32.3% with leg lesions, and 15.4% with lesions at other sites. Molecular identification identified 53 Sporothrix schenckii isolates. Among the 32 patients who were followed up, response to itraconazole was complete or major for 15 and minor for 17. Overall, endemicity of sporotrichosis in Madagascar was high, concentrated in the highlands.