Fungal Integrated Histomolecular Diagnosis Using Targeted Next-Generation Sequencing on Formalin-Fixed Paraffin-Embedded Tissues.

Histopathology is the gold standard for fungal infection (FI) diagnosis, but it does not provide a genus and/or species identification. The objective of the present study was to develop targeted next-generation sequencing (NGS) on formalin-fixed tissue samples (FTs) to achieve a fungal integrated histomolecular diagnosis. Nucleic acid extraction was optimized on a first group of 30 FTs with Aspergillus fumigatus or Mucorales infection by macrodissecting the microscopically identified fungal-rich area and comparing Qiagen and Promega extraction methods through DNA amplification by A. fumigatus and Mucorales primers. Targeted NGS was developed on a second group of 74 FTs using three primer pairs (ITS-3/ITS-4, MITS-2A/MITS-2B, and 28S-12-F/28S-13-R) and two databases (UNITE and RefSeq). A prior fungal identification of this group was established on fresh tissues. Targeted NGS and Sanger sequencing results on FTs were compared. To be valid, the molecular identifications had to be compatible with the histopathological analysis. In the first group, the Qiagen method yielded a better extraction efficiency than the Promega method (100% and 86.7% of positive PCRs, respectively). In the second group, targeted NGS allowed fungal identification in 82.4% (61/74) of FTs using all primer pairs, in 73% (54/74) using ITS-3/ITS-4, in 68.9% (51/74) using MITS-2A/MITS-2B, and in 23% (17/74) using 28S-12-F/28S-13-R. The sensitivity varied according to the database used (81% [60/74] using UNITE compared to 50% [37/74] using RefSeq [P = 0.000002]). The sensitivity of targeted NGS (82.4%) was higher than that of Sanger sequencing (45.9%; P < 0.00001). To conclude, fungal integrated histomolecular diagnosis using targeted NGS is suitable on FTs and improves fungal detection and identification.

Use of 1,3-Beta-D-Glucan concentration in peritoneal fluid for the diagnosis of intra-abdominal Candidiasis in Critically-ill patients.

Intra-Abdominal Candidiasis (IAC) is frequent and associated with high mortality in intensive care unit (ICU) patients. Antifungal treatments may be overused due to a lack of diagnostic tools to rule out IAC. Serum 1,3-Beta-D-Glucan (BDG) concentrations are used to diagnose Candida infections, its concentration in peritoneal fluid (PF) may help to confirm or invalidate the diagnosis of IAC. We performed a non-interventional, prospective, multicenter study, at the Hospices Civils de Lyon, France, in seven ICU located in three different hospitals from December 2017 to June 2018. IAC was defined as the isolation of Candida in a sample collected from the intra-abdominal cavity under sterile conditions in patients displaying clinical evidence of intra-abdominal infection. Among the 113 included patients, 135 PF samples corresponding to 135 intra-abdominal infection episodes were collected and BDG concentrations were assessed. IAC accounted for 28 (20.7%) of the intra-abdominal infections. Antifungals were administered empirically to 70 (61.9%) patients; among them, 23 (32.9%) had an IAC. The median [IQR] BDG value was significantly higher in IAC (8100 [3000;15000] pg/mL) than in non-IAC samples (1961 [332;10650] pg/mL). BDG concentrations were higher in PF with Fecaloid aspect and in case of positive bacterial culture. For a BDG threshold of 125 pg/mL, the negative predictive value to assess IAC was 100%. In conclusion, low BDG PF concentrations could be used to rule out IAC. https://clinicaltrials.gov/ct2/show/NCT03469401.

Intra-Abdominal Candidiasis (IAC) is associated with a high mortality in Intensive Care Unit (ICU) patients. 1,3-Beta-D-Glucan (BDG), a component of Candida cell wall, was prospectively measured in peritoneal fluid from ICU patients Low peritoneal BDG concentrations may be used to rule out IAC.

Evaluation of Serum Mucorales Polymerase Chain Reaction (PCR) for the Diagnosis of Mucormycoses: The MODIMUCOR Prospective Trial.

BACKGROUND: Early diagnosis and prompt initiation of specific antifungal treatment are essential for improving the prognosis of mucormycosis. We aimed to assess the performance of serum Mucorales quantitative polymerase chain reaction (qPCR) for the early diagnosis and follow-up of mucormycosis. METHODS: We prospectively enrolled 232 patients with suspicion of invasive mold disease, evaluated using standard imaging and mycological procedures. Thirteen additional patients with proven or probable mucormycosis were included to analyze DNA load kinetics. Serum samples were collected twice-a-week for Mucorales qPCR tests targeting the Mucorales genera Lichtheimia, Rhizomucor, and Mucor/Rhizopus. RESULTS: The sensitivity was 85.2%, specificity 89.8%, and positive and negative likelihood ratios 8.3 and 0.17, respectively in this prospective study. The first Mucorales qPCR-positive serum was observed a median of 4 days (interquartile range [IQR], 0-9) before sampling of the first mycological or histological positive specimen and a median of one day (IQR, -2 to 6) before the first imaging was performed. Negativity of Mucorales qPCR within seven days after liposomal-amphotericin B initiation was associated with an 85% lower 30-day mortality rate (adjusted hazard ratio = 0·15, 95% confidence interval [.03-.73], P = .02). CONCLUSIONS: Our study argues for the inclusion of qPCR for the detection of circulating Mucorales DNA for mucormycosis diagnosis and follow-up after treatment initiation. Positive results should be added to the criteria for the consensual definitions from the European Organization for the Research and Treatment of Cancer/Mycoses Study Group Education and Research Consortium (EORTC/MSGERC), as already done for Aspergillus PCR.

Malassezia restricta: An Underdiagnosed Causative Agent of Blood Culture-Negative Infective Endocarditis.

BACKGROUND: Infective endocarditis (IE) is a severe disease requiring microbial identification to successfully adapt its treatment. Currently, identification of its etiological microorganism remains unresolved in 5.2% of cases. We aimed to improve IE diagnosis using an ultra-sensitive molecular technique on cardiac samples in microbiologically nondocumented (culture and conventional polymerase chain reaction [PCR]) IE (NDIE) cases. METHODS: Cardiac samples explanted in a tertiary hospital in Lyon, France, from patients with definite IE over a 5-year period were retrospectively analyzed. NDIE was defined as Duke definite-IE associated with negative explorations including cardiac samples culture, bacterial amplification, and serologies. Ultrasensitive molecular diagnosis was achieved using the Universal Microbe Detection kit (Molzym®). Fungal identification was confirmed using 26S-rDNA and internal transcribed spacer amplifications. Fungal infection was confirmed using Grocott-Gromori staining, auto-immunohistochemistry on cardiac samples, and mannan serologies. RESULTS: Among 88 included patients, microbial DNA was detected in all 16 NDIE cases. Bacterial taxa typical of IE etiologies were detected in 13/16 cases and Malassezia restricta in the 3 other cases. In these 3 cases, histological examination confirmed the presence of fungi pathognomonic of Malassezia that reacted with patient sera in an auto-immunohistochemistry assay and cross-reacted with Candida albicans in an indirect immunofluorescent assay. CONCLUSIONS: M. restricta appears to be an underestimated causative agent of NDIE. Importantly, serological cross-reaction of M. restricta with C. albicans may lead to its misdiagnosis. This is of major concern since M. restricta is intrinsically resistant to echinocandins; the reference treatment for Candida-fungal IE.

COVID-19-Associated Pulmonary Aspergillosis, March-August 2020.

Pneumonia caused by severe acute respiratory syndrome coronavirus 2 emerged in China at the end of 2019. Because of the severe immunomodulation and lymphocyte depletion caused by this virus and the subsequent administration of drugs directed at the immune system, we anticipated that patients might experience fungal superinfection. We collected data from 186 patients who had coronavirus disease-associated pulmonary aspergillosis (CAPA) worldwide during March-August 2020. Overall, 182 patients were admitted to the intensive care unit (ICU), including 180 with acute respiratory distress syndrome and 175 who received mechanical ventilation. CAPA was diagnosed a median of 10 days after coronavirus disease diagnosis. Aspergillus fumigatus was identified in 80.3% of patient cultures, 4 of which were azole-resistant. Most (52.7%) patients received voriconazole. In total, 52.2% of patients died; of the deaths, 33.0% were attributed to CAPA. We found that the cumulative incidence of CAPA in the ICU ranged from 1.0% to 39.1%.

Invasive Fungal Infections in Immunocompromised Children: Novel Insight Following a National Study.

OBJECTIVE: To obtain a national overview of the epidemiology and management of invasive fungal infections (IFIs) in France for severely immunocompromised children who were treated for acute leukemia or had undergone allogeneic hematopoietic stem cell transplantation (a-HSCT). STUDY DESIGN: We performed a national multicenter retrospective study to collect epidemiologic data for proven and probable IFIs in children with acute leukemia under first- line or relapse treatment or who had undergone a-HSCT. We also conducted a prospective practice survey to provide a national overview of IFI management in pediatric hematology units. RESULTS: From January 2014 to December 2017, 144 cases of IFI were diagnosed (5.3%) in 2721 patients, including 61 cases of candidiasis, 60 cases of aspergillosis, and 23 cases of infection with "emergent" fungi, including 10 cases of mucormycosis and 6 cases of fusariosis. The IFI rate was higher in patients with acute myelogenous leukemia (12.9%) (OR, 3.24; 95% CI, 2.15-4.81; P < .0001) compared with the rest of the cohort. Patients undergoing a-HSCT had an IFI rate of only 4.3%. In these patients, the use of primary antifungal prophylaxis (principally fluconazole) was associated with a lower IFI rate (OR, 0.28; 95% CI, 0.14-0.60; P = 4.90 ×10-4) compared with a-HSCT recipients who did not receive antifungal prophylaxis. The main cause of IFI in children receiving prophylaxis was emergent pathogens (41%), such as mucormycosis and fusariosis, which were resistant to the prophylactic agents. CONCLUSIONS: The emerging fungi and new antifungal resistance profiles uncovered in this study should be considered in IFI management in immunocompromised children.

Pulmonary aspergillosis in critically ill patients with Coronavirus Disease 2019 (COVID-19).

Occurrence of putative invasive pulmonary aspergillosis was screened in 153 consecutive adult intensive care unit (ICU) patients with respiratory samples addressed for mycological diagnosis during a 6-week period at the emergence of coronavirus disease 2019 (COVID-19) pandemic. Positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) was observed for 106 patients (69.3%). Nineteen of them (17.9%) with positive Aspergillus results were considered as having putative invasive pulmonary aspergillosis. These observations underline the risk of pulmonary aspergillosis in COVID-19 patients, even in patients not previously known to be immunosuppressed, advocating active search for Aspergillus infection and prompt antifungal treatment. Standardized surveillance protocols and updated definitions for ICU putative invasive pulmonary aspergillosis are needed. LAY ABSTRACT: Adult ICU patients with respiratory samples addressed for mycological diagnosis were screened during the emergence of COVID-19 pandemic. Positive SARS-CoV-2 PCR was observed for 106 patients, nineteen of them (17.9%) having aspergillosis. This underlines the risk of aspergillosis in COVID-19 patients.

K3-EDTA differentially inhibits the growth of Candida strains according to their azole resistance status.

The diagnosis of the life-threatening invasive Candida infections is mainly established using culture of specimens that might be collected on different devices including ethylene diamine tetraacetic acid (EDTA)-coated tubes. Despite the knowledge that EDTA inhibits bacterial cultures, and its use to treat oral fungal infections, its impact on Candida cultures has not been completely assessed. This study aimed at assessing it on azole-resistant and azole-susceptible strains. Clinical and American Type Culture Collection (ATCC) strains for Candida albicans (CA), C. glabrata (CGS), C. krusei (CK), azole-susceptible and azole-resistant strains of C. glabrata (CGS and CGR), C. lipolytica (CL), and C. inconspicua (CI) were characterized using MALDI-TOF MS and susceptibility testing and then incubated (1) with serial dilutions of tripotassic EDTA (0%-500% of the concentration in a sample tube) for 2 hours before plating onto ChromID Can2 agar; (2) for 0, 2, 4, 6, 7, or 8 hours at EDTA concentrations at 20% and 33% before seeding; and (3) with sodium citrate or lithium heparinate instead of EDTA for 2 hours before plating. After 48 hours at 35°C, colony-forming units were automatically quantified. An inhibitory effect of EDTA was observed, at different concentrations, for CA (20%), CGS (100%), and CGR (500%) (P < .05), but none was observed for CL, CI, and CK. The effect increased with incubation duration, at a faster rate for azole-susceptible strains. K3-EDTA inhibits Candida growth and EDTA-coated tubes should not be used for mycological culture-based analyses. The correlation between EDTA inhibition and Candida azole-resistance offers perspectives for the development of selective agar and new antifungal strategies.

Investigation of the Relationships Between Clinical and Environmental Isolates of Aspergillus fumigatus by Multiple-locus Variable Number Tandem Repeat Analysis During Major Demolition Work in a French Hospital.

Background: Genotyping is needed to explore the link between clinical cases from colonization of invasive aspergillosis (IA) and major building construction. Attempts to correlate Aspergillus fumigatus strains from clinical infection or colonization with those found in the environment remain controversial due to the lack of a large prospective study. Our aim in this study was to compare the genetic diversity of clinical and environmental A. fumigatus isolates during a demolition period. Methods: Fungal contamination was monitored daily for 11 months in 2015. Environmental surveillance was undertaken indoors and outdoors at 8 locations with automatic agar samplers. IA infection cases were investigated according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group criteria. Isolates were identified by amplification and sequencing of the ß- tubulin gene. They were genotyped by multiple-locus variable number tandem repeat analysis (MLVA). The phylogenetic relationships between isolates were assessed by generating a minimum spanning tree. Results: Based on 3885 samples, 394 A. fumigatus isolates (383 environmental and 11 clinical) were identified and genotyped using MLVA. Clinical isolates were collected from patients diagnosed as having probable IA (n = 2), possible IA (n = 1), or bronchial colonization (n = 6). MLVA generated 234 genotypes. Seven clinical isolates shared genotypes identical to environmental isolates. Conclusions: Among the diversity of genotypes described, similar genotypes were found in clinical and environmental isolates, indicating that A. fumigatus infection and colonization may originate from hospital environments.

Toxoplasmosis in Transplant Recipients, Europe, 2010-2014.

Transplantation activity is increasing, leading to a growing number of patients at risk for toxoplasmosis. We reviewed toxoplasmosis prevention practices, prevalence, and outcomes for hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT; heart, kidney, or liver) patients in Europe. We collected electronic data on the transplant population and prevention guidelines/regulations and clinical data on toxoplasmosis cases diagnosed during 2010-2014. Serologic pretransplant screening of allo-hematopoietic stem cell donors was performed in 80% of countries, screening of organ donors in 100%. SOT recipients were systematically screened in 6 countries. Targeted anti-Toxoplasma chemoprophylaxis was heterogeneous. A total of 87 toxoplasmosis cases were recorded (58 allo-HSCTs, 29 SOTs). The 6-month survival rate was lower among Toxoplasma-seropositive recipients and among allo-hematopoietic stem cell and liver recipients. Chemoprophylaxis improved outcomes for SOT recipients. Toxoplasmosis remains associated with high mortality rates among transplant recipients. Guidelines are urgently needed to standardize prophylactic regimens and optimize patient management.

Quantitative PCR (qPCR) Detection of Mucorales DNA in Bronchoalveolar Lavage Fluid To Diagnose Pulmonary Mucormycosis.

Early diagnosis and treatment are essential to improving the outcome of mucormycosis. The aim of this retrospective study was to assess the contribution of quantitative PCR detection of Mucorales DNA in bronchoalveolar lavage fluids for early diagnosis of pulmonary mucormycosis. Bronchoalveolar lavage fluid samples (n = 450) from 374 patients with pneumonia and immunosuppressive conditions were analyzed using a combination of 3 quantitative PCR assays targeting the main genera involved in mucormycosis in France (Rhizomucor, Mucor/Rhizopus, and Lichtheimia). Among these 374 patients, 24 patients had at least one bronchoalveolar lavage fluid sample with a positive PCR; 23/24 patients had radiological criteria for invasive fungal infections according to consensual criteria; 10 patients had probable or proven mucormycosis, and 13 additional patients had other invasive fungal infections (4 probable aspergillosis, 1 proven fusariosis, and 8 possible invasive fungal infections). Only 2/24 patients with a positive PCR result on a bronchoalveolar lavage fluid sample had a positive Mucorales culture. PCR was also positive on serum in 17/24 patients. In most cases, a positive PCR result was first detected using sera (15/17). However, a positive PCR on bronchoalveolar lavage fluid was the earliest and/or the only biological test revealing mucormycosis in 4 patients with a final diagnosis of probable or proven mucormycosis, 3 patients with probable aspergillosis, and one patient with a possible invasive fungal infection. Mucorales PCR performed on bronchoalveolar lavage fluid could provide additional support for earlier administration of Mucorales-directed antifungal therapy, thus improving the outcome of lung mucormycosis cases.

Donor Derived Candida stellimalicola in a Clinical Specimen: Preservation Fluid Contamination During Pancreas Procurement.

We report here a case of possible donor-derived Candida stellimalicola infection after pancreas transplantation. Candida stellimalicola, an environmental non-filamentous yeast, was isolated from both the peritoneal fluid of the graft donor and the preservation fluid of the transplanted pancreas. Interestingly, this strain exhibited high minimum inhibitory concentrations to azoles. These results justified the use of echinocandins as therapy instead of fluconazole. This switch permitted a favorable outcome. To our knowledge, this is the first report of C. stellimalicola from clinical samples and therefore the first reported case of a possible human infection. This case report highlights the need for standardized microbiological procedures in solid organ transplant settings. Moreover, it underlines the importance of using molecular identification technique when routine techniques do not allow successful identification of the pathogen. It is of utmost importance to determine sensitivity profile, even in the absence of species-level identification, because resistance to fluconazole is not uncommon, especially in emergent species.

Rare and unusual presentation of Cladophialophora infection in a pulmonary transplant cystic fibrosis patient.

A 35-year-old woman with severe cystic fibrosis was admitted for sudden loss of strength in both legs, revealing a myelitis. The medullary lesion biopsy revealed phaeohyphomycosis caused by Cladophialophora species. Myelitis caused by Cladophialophora bantiana is a rare disease associated with high mortality.

Dermatophytes and transmission risks to family: a retrospective study of a cohort of 256 adopted children from 1998 to 2012.

In this 14-year retrospective study we analyzed samples collected from 101 adopted children originating from developing countries in search of dermatophytosis; a dermatophyte was isolated in 44 children. We demonstrated that dermatophytoses often have a silent clinical presentation (16%) and in approximately 20% of cases cause family member contamination. This study highlights the importance of the clinical examination of children and families as well as systematic sampling of children to avoid dermatophyte transmission to other family members.

Gradient concentration strip-specific epidemiological cut-off values of antifungal drugs in various yeast species and five prevalent Aspergillus species complexes.

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.

Improving Diagnosis of Pulmonary Mucormycosis: Leads From a Contemporary National Study of 114 Cases.

BACKGROUND: Pulmonary mucormycosis (PM) is a life-threatening invasive mold infection. Diagnosis of mucormycosis is challenging and often delayed, resulting in higher mortality. RESEARCH QUESTION: Are the disease presentation of PM and contribution of diagnosis tools influenced by the patient's underlying condition? STUDY DESIGN AND METHODS: All PM cases from six French teaching hospitals between 2008 and 2019 were retrospectively reviewed. Cases were defined according to updated European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria with the addition of diabetes and trauma as host factors and positive serum or tissue PCR as mycologic evidence. Thoracic CT scans were reviewed centrally. RESULTS: A total of 114 cases of PM were recorded, including 40% with disseminated forms. Main underlying conditions were hematologic malignancy (49%), allogeneic hematopoietic stem cell transplantation (21%), and solid organ transplantation (17%). When disseminated, main dissemination sites were the liver (48%), spleen (48%), brain (44%), and kidneys (37%). Radiologic presentation included consolidation (58%), pleural effusion (52%), reversed halo sign (26%), halo sign (24%), vascular abnormalities (26%), and cavity (23%). Serum quantitative polymerase chain reaction (qPCR) was positive in 42 (79%) of 53 patients and BAL in 46 (50%) of 96 patients. Results of transthoracic lung biopsy were diagnostic in 8 (73%) of 11 patients with noncontributive BAL. Overall 90-day mortality was 59%. Patients with neutropenia more frequently displayed an angioinvasive presentation, including reversed halo sign and disseminated disease (P < .05). Serum qPCR was more contributive in patients with neutropenia (91% vs 62%; P = .02), and BAL was more contributive in patients without neutropenia (69% vs 41%; P = .02). Serum qPCR was more frequently positive in patients with a > 3 cm main lesion (91% vs 62%; P = .02). Overall, positive qPCR was associated with an early diagnosis (P = .03) and treatment onset (P = .01). INTERPRETATION: Neutropenia and radiologic findings influence disease presentation and contribution of diagnostic tools during PM. Serum qPCR is more contributive in patients with neutropenia and BAL examination in patients without neutropenia. Results of lung biopsies are highly contributive in cases of noncontributive BAL.

Fatal Community-Acquired Peritonitis Due to Invasive Necrotizing Intestinal Mucormycosis: Case Report and Review of the Literature.

We report here a rare case of fatal rapidly progressive necrotizing gastrointestinal mucormycosis due to Mucor circinelloides f. circinelloides in the setting of community-acquired peritonitis, in an immunocompromised adult patient. Diagnosis was established by direct examination of peritoneal fluid showing hyphae consistent with mucormycosis confirmed by the culture.

[Invasive fungal infections in immunocompromised children in paediatric haematology: Recommendations for management in SFCE centres]. / Infections fongiques invasives chez l'enfant immunodéprimé en hématologie pédiatrique : recommandations de prise en charge au sein des centres de la SFCE.

INTRODUCTION: To date, invasive fungal infections (IFIs) are still responsible for a high mortality rate in children managed for haematological malignancy. Although Candida and Aspergillus infections remain in the majority, emerging fungal infections are increasingly common. Children differ from adults in their pathology and treatment, as well as in their prior fungal colonisation and unique pharmacokinetics. Therefore, we propose here specific paediatric management recommendations for IFIs in haematology. METHODS: We based our recommendations on a review of the literature, including the latest ECIL recommendations, an analysis of practices and a collection of expert opinions. RESULTS AND DISCUSSION: In France, approximately 5% of children treated for haematological malignancy or who have received a bone marrow allograft present an IFI. These IFIs are equally divided between yeast infections (mainly due to Candida albicans) and filamentous infections (mainly aspergillosis) and 16% are IFIs due to emerging fungi, half of which are due to Mucorales. In these recommendations, we recall the diagnostic criteria for proven or probable IFI according to the Donnelly classification, then we propose strategies for screening, diagnosing, evaluating the extension and treating these three types of IFI. We also detail the diagnostic and therapeutic management of chronic disseminated candidiasis. We also discuss prophylactic measures, including environmental measures which are of primary importance in children.

Chronic Toxoplasma gondii infection and sleep-wake alterations in mice.

AIM: Toxoplasma gondii (Tg) is an intracellular parasite infecting more than a third of the human population. Yet, the impact of Tg infection on sleep, a highly sensitive index of brain functions, remains unknown. We designed an experimental mouse model of chronic Tg infection to assess the effects on sleep-wake states. METHODS: Mice were infected using cysts of the type II Prugniaud strain. We performed chronic sleep-wake recordings and monitoring as well as EEG power spectral density analysis in order to assess the quantitative and qualitative changes of sleep-wake states. Pharmacological approach was combined to evaluate the direct impact of the infection and inflammation caused by Tg. RESULTS: Infected mouse exhibited chronic sleep-wake alterations over months, characterized by a marked increase (>20%) in time spent awake and in cortical EEG θ power density of all sleep-wake states. Meanwhile, slow-wave sleep decreased significantly. These effects were alleviated by an anti-inflammatory treatment using corticosteroid dexamethasone. CONCLUSION: We demonstrated for the first time the direct consequences of Tg infection on sleep-wake states. The persistently increased wakefulness and reduced sleep fit with the parasite's strategy to enhance dissemination through host predation and are of significance in understanding the neurodegenerative and neuropsychiatric disorders reported in infected patients.

Serology for Toxoplasma in Immunocompromised Patients: Still Useful?

Toxoplasmosis represents one of the most common comorbidity factors in solid organ or hematopoietic stem cell transplant recipients as well as in other immunocompromised patients. In the past decades, availability and performance of molecular tools for the diagnosis or the exclusion of toxoplasmosis in these patients have greatly improved. However, if accurately used, serology remains a complementary and essential diagnostic tool for physicians and medical parasitologists for the prevention and management of toxoplasmosis in immunocompromised patients as well. It is required for determination of the immunological status of patients against Toxoplasma. It also helps diagnose and monitor complex cases of opportunistic Toxoplasma infection in immunocompromised patients. New perspectives are available to further enhance their yield and ease of use.