Multicenter evaluation of the Toxoplasma gondii Real-TM (Sacace) kit performance for the molecular diagnosis of toxoplasmosis.

The molecular detection of Toxoplasma gondii DNA is a key tool for the diagnosis of disseminated and congenital toxoplasmosis. This multicentric study from the Molecular Biology Pole of the French National Reference Center for toxoplasmosis aimed to evaluate Toxoplasma gondii Real-TM PCR kit (Sacace). The study compared the analytical and clinical performances of this PCR assay with the reference PCRs used in proficient laboratories. PCR efficiencies varied from 90% to 112%; linearity zone extended over four log units (R2 > 0.99) and limit of detection varied from 0.01 to ≤1 Tg/mL depending on the center. Determined on 173 cryopreserved DNAs from a large range of clinical specimens, clinical sensitivity was 100% [106/106; 95 confidence interval (CI): 96.5%-100%] and specificity was 100% (67/67; 95 CI: 94.6%-100%). The study revealed two potential limitations of the Sacace PCR assay: the first was the inconsistency of the internal control (IC) when added to the PCR mixture. This point was not found under routine conditions when the IC was added during the extraction step. The second is a lack of practicality, as the mixture is distributed over several vials, requiring numerous pipetting operations. Overall, this study provides useful information for the molecular diagnosis of toxoplasmosis; the analytical and clinical performances of the Sacace PCR kit were satisfactory, the kit having sensitivity and specificity similar to those of expert center methods and being able to detect low parasite loads, at levels where multiplicative analysis gives inconsistently positive results. Finally, the study recommends multiplicative analysis in particular for amniotic fluids, aqueous humor, and other single specimens.

Characteristics and Prognosis Factors of Pneumocystis jirovecii Pneumonia According to Underlying Disease: A Retrospective Multicenter Study.

BACKGROUND: Pneumocystis jirovecii pneumonia (PcP) remains associated with high rates of mortality, and the impact of immunocompromising underlying disease on the clinical presentation, severity, and mortality of PcP has not been adequately evaluated. RESEARCH QUESTION: Does the underlying disease and immunosuppression causing PcP impact the outcome and clinical presentation of the disease? STUDY DESIGN AND METHODS: In this multicenter retrospective observational study, conducted from January 2011 to December 2021, all consecutive patients admitted with a proven or probable diagnosis of PcP according to the European Organisation for Research and Treatment of Cancer consensus definitions were included to assess the epidemiology and impact of underlying immunosuppressive diseases on overall and 90-day mortality. RESULTS: Overall, 481 patients were included in the study; 180 (37.4%) were defined as proven PcP and 301 (62.6%) were defined as probable PcP. Patients with immune-mediated inflammatory diseases (IMIDs) or solid tumors had a statistically poorer prognosis than other patients with PcP at day 90. In multivariate analysis, among the HIV-negative population, solid tumor underlying disease (OR, 5.47; 95% CI, 2.16-14.1; P < .001), IMIDs (OR, 2.19; 95% CI, 1.05-4.60; P = .037), long-term corticosteroid exposure (OR, 2.07; 95% CI, 1.03-4.31; P = .045), cysts in sputum/BAL smears (OR, 1.92; 95% CI, 1.02-3.62; P = .043), and SOFA score at admission (OR, 1.58; 95% CI, 1.39-1.82; P < .001) were independently associated with 90-day mortality. Prior corticotherapy was the only immunosuppressant associated with 90-day mortality (OR, 1.67; 95% CI, 1.03-2.71; P = .035), especially for a prednisone daily dose ≥ 10 mg (OR, 1.80; 95% CI, 1.14-2.85; P = .010). INTERPRETATION: Among patients who were HIV-negative, long-term corticosteroid prior to PcP diagnosis was independently associated with increased 90-day mortality, specifically in patients with IMIDs. These results highlight both the needs for PcP prophylaxis in patients with IMIDs and to early consider PcP curative treatment in severe pneumonia among patients with IMIDs.

Draft Genome Sequence of the Fluconazole-Resistant Yarrowia lipolytica Clinical Isolate CBS 18115.

Yarrowia lipolytica is a nonconventional yeast of industrial interest that can sometimes act as an opportunistic pathogen and is responsible for invasive fungal infections. We report the draft genome sequence of the fluconazole-resistant strain CBS 18115, which was isolated from a blood culture. The Y132F substitution in ERG11, which was previously described in fluconazole-resistant Candida isolates, was identified.

Acquired fluconazole resistance and genetic clustering in Diutina (Candida) catenulata from clinical samples.

OBJECTIVES: Diutina (Candida) catenulata is an ascomycetous yeast isolated from environmental sources and animals, occasionally infecting humans. The aim of this study is to shed light on the in vitro antifungal susceptibility and genetic diversity of this opportunistic yeast. METHODS: Forty-five D. catenulata strains isolated from various sources (including human and environmental sources) and originating from nine countries were included. Species identification was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and confirmed via internal transcribed spacer ribosomal DNA barcoding. In vitro antifungal susceptibility was determined for seven systemic antifungals via the gradient strip method after 48 hours of incubation at 35°C using Etest® (Biomérieux) or Liofilchem® strips. Isolates exhibiting fluconazole minimal inhibitory concentrations (MICs) of ≥8 µg/mL were investigated for mutations in the ERG11 gene. A novel microsatellite genotyping scheme consisting of four markers was developed to assess genetic diversity. RESULTS: MIC ranges for amphotericin B, caspofungin, micafungin, isavuconazole, and posaconazole were 0.19-1 µg/mL, 0.094-0.5 µg/mL, 0.012-0.064 µg/mL, 0.003-0.047 µg/mL, and 0.006-0.032 µg/mL, respectively. By comparison, a broad range of MICs was noted for fluconazole (0.75 to >256 µg/mL) and voriconazole (0.012-0.38 mg/L), the higher values being observed among clinical strains. The Y132F amino acid substitution, associated with azole resistance in various Candida species (C. albicans, C. tropicalis, C. parapsilosis, and C. orthopsilosis), was the main substitution identified. Although microsatellite typing showed extensive genetic diversity, most strains with high fluconazole MICs clustered together, suggesting human-to-human transmission or a common source of contamination. DISCUSSION: The high rate of acquired fluconazole resistance among clinical isolates of D. catenulata is of concern. In this study, we highlight a link between the genetic diversity of D. catenulata and its antifungal resistance patterns, suggesting possible clonal transmission of resistant isolates.

Draft Genome Sequence of the Fluconazole-Resistant Candida palmioleophila Clinical Isolate CBS 18098.

Candida palmioleophila belongs to the Saccharomycetales. This opportunistic yeast which has been associated with invasive infections in human and animals, warrants a specific attention as it is frequently misidentified and display reduced susceptibility to fluconazole. Here, we report the first draft genome of C. palmioleophila, obtained from a clinical isolate.

Aspergillosis in a colony of Humboldt penguins (Spheniscus humboldti) under managed care: a clinical and environmental investigation in a French zoological park.

Aspergillosis is pervasive in bird populations, especially those under human care. Its management can be critically impacted by exposure to high levels of conidia and by resistance to azole drugs. The fungal contamination in the environment of a Humboldt penguin (Spheniscus humboldti) group, housed in a French zoological park next to numerous large crop fields, was assessed through three serial sessions of surface sampling in nests, in 2018-20: all isolates were counted and characterized by sequencing. When identified as Aspergillus fumigatus, they were systematically screened for resistance mutations in the cyp51A gene and tested for minimal inhibitory concentrations (MICs) determination. At the same time, the clinical incidence of aspergillosis was evaluated in the penguin population by the means of systematic necropsy and mycological investigations. A microsatellite-based analysis tracked the circulation of A. fumigatus strains. Environmental investigations highlighted the substantial increase of the fungal load during the summer season (>12-fold vs. the other timepoints) and a large overrepresentation of species belonging to the Aspergillus section Fumigati, ranging from 22.7 to 94.6% relative prevalence. Only one cryptic species was detected (A. nishimurae), and one isolate exhibited G138S resistance mutation with elevated MICs. The overall incidence of aspergillosis was measured at ∼3.4% case-years, and mostly in juveniles. The analysis of microsatellite polymorphism revealed a high level of genetic diversity among A. fumigatus clinical isolates. In contrast, one environmental strain appeared largely overrepresented during the summer sampling session. In all, the rural location of the zoo did not influence the emergence of resistant strains.

The Novodiag® Stool parasites assay, an innovative high-plex technique for fast detection of protozoa, helminths and microsporidia in stool samples: a retrospective and prospective study.

OBJECTIVES: We provide the first evaluation of the CE-IVD marked Novodiag® stool parasites assay (NVD), allowing rapid and high-plex detection of 26 distinct targets, encompassing protozoans, helminths and microsporidia in stool samples. METHODS: A total of 254 samples (n = 205 patients) were prospectively processed by the NVD and our routine procedure (RP). Performances of the NVD were compared with RP. Samples only positive by the NVD assay were investigated by external PCR assays. Sensitivity and specificity (Se/Sp) and time from sample receipt to results were determined for each method. The NVD was also evaluated against 77 additional samples positive for a wide range of parasites. RESULTS: Overall positivity rate was 16.9% for RP compared with 34% using the NVD assay, and 164 samples (66%) were negative by both methods. Only 30 positive samples (12%) showed full concordance between RP and NVD. Fifty-three discordant samples were sent for external investigations. Except for Giardia intestinalis and Trichuris spp., higher Se was observed for the NVD assay for Blastocystis spp. (100% vs. 63%), Dientamoeba fragilis (100% vs. 0%), Schistosoma spp. (100% vs. 17%), and Enterobius vermicularis (100% vs. 67%) but roughly similar to RP for the remaining parasites tested. False-positive results were identified for Blastocystis spp., G. intestinalis, and Trichuris spp. using the NVD assay. The NVD mostly provides a diagnosis on the day of sample receipt compared with a mean of three days with RP. CONCLUSIONS: Besides some limitations, the NVD is a new diagnostic strategy allowing rapid and high-plex detection of gastrointestinal parasites from unpreserved stools.

Title: Le test Novodiag® Stool parasites, une technique high-plex innovante pour la détection rapide des protozoaires, helminthes et microsporidies dans les échantillons de selles : une étude rétrospective et prospective. Abstract: Objectifs : Nous présentons la première évaluation du kit Novodiag® Stool parasite (NVD) marqué CE-IVD, permettant la détection rapide de 26 cibles distinctes dans les selles (protozoaires, helminthes et microsporidies). Méthodes : Un total de 254 échantillons (n = 205 patients) a été traité prospectivement par le NVD et notre procédure de routine (PR). Les performances du NVD ont été comparées à celles de la PR. Seuls les échantillons positifs au test NVD ont été étudiés par des PCR externes. La sensibilité et la spécificité (Se/Sp) ainsi que le temps écoulé entre la réception de l'échantillon et les résultats ont été déterminés pour chaque méthode. Le NVD a également été évalué par rapport à 77 échantillons supplémentaires positifs pour un large éventail de parasites. Résultats : Le taux de positivité global était de 16,9 % pour la PR contre 34 % avec le NVD, et 164 échantillons (66 %) étaient négatifs par les deux méthodes. Seuls 30 échantillons positifs (12 %) ont montré une concordance complète entre la PR et le NVD. Cinquante-trois échantillons discordants ont été envoyés pour des investigations externes. À l'exception de Giardia intestinalis et de Trichuris spp., des Se plus élevées ont été observées pour le test NVD pour Blastocystis spp. (100 % contre 63 %), Dientamoeba fragilis (100 % contre 0 %), Schistosoma spp. (100 % contre 17 %), Enterobius vermicularis (100 % contre 67 %) mais étaient à peu près similaires à la PR pour les autres parasites testés. Des faux positifs ont été identifiés pour Blastocystis spp., G. intestinalis et Trichuris spp. en utilisant le NVD. Le NVD fournit le plus souvent un diagnostic le jour de la réception du prélèvement contre une moyenne de trois jours avec la PR. Conclusions : Malgré quelques limites, le test NVD est une nouvelle stratégie de diagnostic permettant une détection rapide et high-plex des parasites gastro-intestinaux à partir de selles non conservées.

Circulation of an Artemisinin-Resistant Malaria Lineage in a Traveler Returning from East Africa to France.

A returned traveler to Uganda presented with a Plasmodium falciparum kelch13 A675V mutant infection that exhibited delayed clearance under artesunate therapy. Parasites were genetically related to recently reported Ugandan artemisinin-resistant A675V parasites. Adequate malaria prevention measures and clinical and genotypic surveillance are important tools to avoid and track artemisinin resistance.

Impact of TR34/L98H, TR46/Y121F/T289A and TR53 Alterations in Azole-Resistant Aspergillus fumigatus on Sterol Composition and Modifications after In Vitro Exposure to Itraconazole and Voriconazole.

BACKGROUND: Sterols are the main components of fungal membranes. Inhibiting their biosynthesis is the mode of action of azole antifungal drugs that are widely used to treat fungal disease including aspergillosis. Azole resistance has emerged as a matter of concern but little is known about sterols biosynthesis in azole resistant Aspergillus fumigatus. METHODS: We explored the sterol composition of 12 A. fumigatus isolates, including nine azole resistant isolates with TR34/L98H, TR46/Y121F/T289A or TR53 alterations in the cyp51A gene and its promoter conferring azole resistance. Modifications in sterol composition were also investigated after exposure to two azole drugs, itraconazole and voriconazole. RESULTS: Overall, under basal conditions, sterol compositions were qualitatively equivalent, whatever the alterations in the target of azole drugs with ergosterol as the main sterol detected. Azole exposure reduced ergosterol composition and the qualitative composition of sterols was similar in both susceptible and resistant isolates. Interestingly TR53 strains behaved differently than other strains. CONCLUSIONS: Elucidating sterol composition in azole-susceptible and resistant isolates is of interest for a better understanding of the mechanism of action of these drugs and the mechanism of resistance of fungi.

Epidemiology and Clinical Impact of Respiratory Coinfections at Diagnosis of Pneumocystis jirovecii Pneumonia.

BACKGROUND: The role of respiratory coinfections at diagnosis of Pneumocystis jirovecii pneumonia (PcP) on clinical impact has been underestimated. METHODS: A retrospective observational study was conducted January 2011 to April 2019 to evaluate respiratory coinfections at diagnosis of PcP patients in 2 tertiary care hospitals. Coinfection was defined by identification of pathogens from P. jirovecii-positive samples. RESULTS: Of 7882 respiratory samples tested for P. jirovecii during the 8-year study, 328 patients with diagnosis of PcP were included. Mean age was 56.7 (SD 14.9) years, 193 (58.8%) were male, 74 (22.6%) had positive HIV serology, 125 (38.1%) had viral coinfection, 76 (23.2%) bacterial coinfection, and 90-day mortality was 25.3%. In the overall population, 90-day mortality was independently associated with solid tumor underlying disease (odds ratio [OR], 11.8; 95% confidence interval [CI], 1.90-78.0; P = .008), sepsis-related organ failure assessment score (SOFA) at admission (OR, 1.62; 95% CI, 1.34-2.05; P< .001), and cytomegalovirus (CMV) respiratory coinfection (OR, 3.44; 95% CI, 1.24-2.90; P = .02). Among HIV-negative patients, respiratory CMV coinfection was associated with worse prognosis, especially when treated with adjunctive corticosteroid therapy. CONCLUSIONS: Respiratory CMV coinfection at PcP diagnosis was independently associated with increased 90-day mortality, specifically in HIV-negative patients.

Collateral consequences of agricultural fungicides on pathogenic yeasts: A One Health perspective to tackle azole resistance.

Candida and Cryptococcus affect millions of people yearly, being responsible for a wide array of clinical presentations, including life-threatening diseases. Interestingly, most human pathogenic yeasts are not restricted to the clinical setting, as they are also ubiquitous in the environment. Recent studies raise concern regarding the potential impact of agricultural use of azoles on resistance to medical antifungals in yeasts, as previously outlined with Aspergillus fumigatus. Thus, we undertook a narrative review of the literature and provide lines of evidence suggesting that an alternative, environmental route of azole resistance, may develop in pathogenic yeasts, in addition to patient route. However, it warrants sound evidence to support that pathogenic yeasts cross border between plants, animals and humans and that environmental reservoirs may contribute to azole resistance in Candida or other yeasts for humans. As these possibilities could concern public health, we propose a road map for future studies under the One Health perspective.

In vitro antifungal effect of a plant-based product, CIN-102, on antifungal resistant filamentous fungi and their biofilms.

Introduction. The increase of invasive fungal infections (IFIs) and associated treatment failure in populations at risk is driving us to look for new treatments.Hypothesis. The CIN-102 compound, derived from cinnamon essential oil, could be a new antifungal class with an activity, in particular, on strains resistant to current antifungals but also on biofilms, a factor of virulence and resistance of fungi.Aim. The aim of this study is to show the activity of CIN-102 on various strains resistant to current antifungals, on the biofilm and to determine the possibility of resistance induced with this compound.Methodology. We studied the MIC of CIN-102 and of current antifungals (voriconazole and amphotericin B) using CLSI techniques against eight different strains of three genera of filamentous fungi involved in IFIs and having resistance phenotypes to current antifungals. We also determined their effects on biofilm formation, and the induced resistance by voriconazole (VRC) and CIN-102.Results. MIC values determined for CIN-102 were between 62.5 and 250 µg ml-1. We demonstrated the antifungal effect of CIN-102 on biofilm, and more particularly on its formation, with 100 % inhibition achieved for most of the strains. CIN-102 at a sub-inhibitory concentration in the medium did not induce resistance in our strains, even after 30 generations.Conclusions. In this study we show that CIN-102 is effective against resistant filamentous fungi and against biofilm formation. In addition, our strains did not acquire a resistance phenotype against CIN-102 over time, unlike with VRC. CIN-102 is therefore an interesting candidate for the treatment of IFIs, including in cases of therapeutic failure linked to resistance, although further studies on its efficacy, safety and mechanism of action are needed.

Characterisation of the antifungal effects of a plant-based compound, CIN-102, on the main septal filamentous fungi involved in human pathology.

OBJECTIVES: Today, the increase of invasive fungal infections and the emergence of resistant strains are observed in medical practice. New antifungals are expected, and the plant world offers a panel of potentially active molecules. CIN-102 is a mixture of seven different compounds of plant origin developed from the formulation of cinnamon essential oil. METHODS: The in vitro activity of CIN-102 was characterised against Aspergillus spp., Fusarium spp. and Scedosporium spp. by studying the minimum inhibitory concentration (MIC), inoculum effect, germination inhibition, fungal growth, post-antifungal effect (PAFE) and synergy. RESULTS: MICs determined for the three genera followed a unimodal distribution and their mean values ranged from 62-250 µg/mL. CIN-102 demonstrated an inoculum effect similar to voriconazole and amphotericin B, 100% inhibition of spore germination and a PAFE. CONCLUSION: CIN-102 has significant activity against filamentous fungi involved in human pathologies and should be further explored as a potential new treatment. Other studies regarding its mechanisms of action as well as animal investigations are awaited.

Serum (1 → 3)-ß-D-glucan could be useful to rule out invasive candidiasis in neonates with an adapted cut-off.

AIM: We assessed the diagnostic accuracy of serum (1 â†’ 3)-ß-D-glucan (BDG) for neonatal invasive candidiasis (NIC) using the recommended cut-off usually used in adults for detecting invasive candidiasis and searched for an optimal cut-off for ruling out NIC. METHODS: We conducted a prospective cross-sectional study at Nantes University medical centre from January 2017 to July 2018. All consecutive newborn infants of less than 28 days of corrected age, with clinically suspected NIC, who underwent BDG assay, were included. Sensitivity and specificity were calculated by using the recommended cut-off of 80 pg/mL. Receiver operating characteristic curve analysis was used to identify an optimal cut-off value. RESULTS: We included 55 newborn infants with 61 episodes of suspected NIC. Their median gestational and chronological ages were 28.0 weeks (interquartile range [IQR] 26.4-34.1) and 10.0 days (IQR 6.0-22.0), respectively. Of 61 episodes, seven revealed NIC. Sensitivity and specificity were 85.7% (95% confidence interval [CI] 42.1%-99.6%) and 51.9% (37.8%-65.7%) with the recommended cut-off, respectively. An optimal cut-off of 174 pg/mL offered the same sensitivity but higher specificity 77.8% (64.4%-88.0%). CONCLUSION: The recommended cut-off of 80 pg/mL was probably too low for ruling out NIC. A higher cut-off might have been more appropriate.

Hormographiella aspergillata: an emerging basidiomycete in the clinical setting? A case report and literature review.

BACKGROUND: Filamentous basidiomycetes are mainly considered to be respiratory tract colonizers but the clinical significance of their isolation in a specimen is debatable. Hormographiella aspergillata was first reported as a human pathogen in 1971. We discuss the role of this mold as a pathogen or colonizer and give an update on diagnostic tools and in vitro antifungal susceptibility. CASE PRESENTATION: We identified three cases of H. aspergillata with respiratory symptoms in a short period of time. One invasive infection and two colonizations were diagnosed. Culture supernatants showed that H. aspergillata can produce galactomannan and ß-D-glucan but not glucuronoxylomannan. For the first time, isavuconazole susceptibility was determined and high minimum inhibitory concentrations (MICs) were found. Liposomal amphotericin B and voriconazole have the lowest MICs. CONCLUSION: To date, 22 invasive infections involving H. aspergillata have been reported. On isolation of H. aspergillata, its pathogenic potential in clinical settings can be tricky. Molecular identification and antifungal susceptibility testing are essential considering high resistance against several antifungal therapies.

Ultrasound features of fetal toxoplasmosis: A contemporary multicenter survey in 88 fetuses.

OBJECTIVE: To describe the lesions detected by prenatal ultrasound examination in congenital toxoplasmosis (CT). METHODS: We retrospectively analyzed all cases of fetal infection with Toxoplasma gondii with ultrasound anomalies described by fetal medicine experts in 2009 to 2019 in 30 French centers. RESULTS: Eighty-eight cases of CT were included. Forty-five (51.1%) had one or more cerebral signs only, 35 (39.8%) had cerebral plus extracerebral signs and 8 (9.1%) had extracerebral signs only. The main cerebral signs were intracranial hyperechogenic nodular foci (n = 60) of which 20 were isolated, ventriculomegalies (n = 44) which generally increased during follow-up, and periventricular abscesses (n = 12). The main extracerebral signs were hepatomegaly and/or splenomegaly (n = 14), small for gestational age (n = 14), ascites (n = 14, including 2 with hydrops), and hyperechogenic bowel (n = 11). Maternal infection occurred mostly in the first or second trimester (81 cases), periconceptionally in one and in the third trimester in six cases. The first ultrasound signs were detected after a median of 7 weeks (range: 1.4; 24.0) following maternal toxoplasmosis seroconversion. CONCLUSION: While no sign was specific of CT, there were typical associations of cerebral signs with or without extracerebral signs. Detailed ultrasound examination could improve prognostic evaluation, as well as diagnosis of CT in settings lacking serological screening.

Medicopsis romeroi nodular subcutaneous infection in a kidney transplant recipient.

Phaeohyphomycosis is a set of fungal infections caused by various dematiaceous fungi such as coelomycetes. These infections can occur either in immunocompetent or immunocompromised patients like solid organ transplants. Here we describe a nodular lesion of the right hallux that occurred in a kidney transplant patient. Microscopic examination of the biopsy revealed fungal hyphae and culture was positive to a grey to black mould that lacked characteristic elements to be identified. Nucleic acid sequencing targeting the internal transcribed spacer of the ribosomal DNA identified this mould as Medicopsis romeroi. The patient benefited of an antifungal therapy with voriconazole associated with surgical excision of the lesion. No relapse of the lesion was observed during a six-month follow-up. In solid organ transplants, phaeohyphomycosis caused by Medicopsis romeroi are very rare with only 12 cases reported. The clinical history should be well assessed since the lesion can appear several years after a cutaneous trauma that happened in a tropical region. Therapy generally combines antifungals with surgical excision of the lesion in order to avoid any relapse or dissemination of the infection.

Mucorales DNA detection in serum specimens for early diagnosis of mucormycosis.

We report a case of pulmonary mucormycosis in a patient with T-cell acute lymphoblastic leukemia. The diagnosis of mucormycosis was initially based on mycological examination of a pulmonary specimen. However, we describe how it could have been made 2 months earlier using polymerase chain reaction assays targeting Mucorales species on serum specimens.

Serological diagnosis of Toxoplasma gondii: analysis of false-positive IgG results and implications.

BACKGROUND: Primary infection by Toxoplasma gondii in pregnant women can result in serious outcomes for the foetus. A false-positive IgG result during pregnancy can lead to a misdiagnosis of past infection and to stopping preventive measures. We collected 189 sera with positive Architect® Toxo IgG assay (Abbott Laboratories) and negative IgG results with at least two other serological tests, in order to find an explanation for the suspected false-positive IgG results. We used the recomLine Toxoplasma IgG® immunoblot (Mikrogen Diagnostik) to search for specific antigenic reactivities of the sera, and the LDBio Toxo II IgG® immunoblot (LDBio Diagnostics) as a confirmatory test. RESULTS: The bands GRA8 and/or GRA7 were positive for 148 samples (78.3%). GRA8 was the most frequent band, appearing in 133 patterns (70.4%), whereas GRA7 was present for 49 samples (25.9%). Of the 81 samples tested with LDBio®, 23 (28.4%) turned out to be positive. Of the 58 negative LDBio® tests (71.6%) (real false-positive Architect® IgG), 23 samples (39.6%) did not show either a GRA8 or p30 band by recomLine®. Their false positivity with Architect® remains unexplained since Abbott uses these two recombinant antigens for their assay. CONCLUSIONS: The Architect® IgG false positivity for T. gondii seems to be due to reactivity against GRA8 for the majority of the sera and GRA7 to a lesser extent. The hypothesis of past contact with parasites genetically close to T. gondii such as Hammondia hammondi or Neospora caninum seems promising and should be assessed further.

TITLE: Diagnostic sérologique de Toxoplasma gondii : analyse des IgG faux positifs et implications. ABSTRACT: Contexte : La primo-infection à Toxoplasma gondii chez la femme enceinte peut avoir de graves conséquences pour le fœtus. Un résultat IgG faussement positif pendant la grossesse peut mener à un diagnostic erroné d'infection ancienne et à stopper les mesures préventives. Nous avons collecté 189 sérums présentant un résultat Architect® Toxo IgG (Abbott Laboratories) positif ainsi qu'un résultat IgG négatif par au moins deux autres tests sérologiques, dans le but de trouver une explication aux résultats IgG suspectés faux positifs. Nous avons utilisé l'immunoblot recomLine Toxoplasma IgG® (Mikrogen Diagnostik) pour chercher certaines réactivités antigéniques spécifiques des sérums et l'immunoblot LDBio Toxo II IgG® (LDBio Diagnostics) comme test de confirmation. Résultats : Les bandes GRA8 et/ou GRA7 étaient positives pour 148 (78,3 %) échantillons. GRA8 était la bande la plus fréquente, apparaissant dans 133 (70,4 %) profils alors que GRA7 était présente pour 49 (25,9 %) échantillons. Sur les 81 échantillons testés en LDBio®, 23 (28,4 %) se sont révélés positifs. Sur les 58 (71,6 %) tests LDBio® négatifs (réels faux positifs IgG Architect®), 23 (39,6 %) échantillons n'ont montré ni bande GRA8 ni bande p30 en recomLine® et leur fausse positivité reste donc inexpliquée puisque Abbott utilise ces deux antigènes recombinants dans son test. Conclusions : La fausse positivité IgG Architect® pour T. gondii semble être due à une réactivité envers la protéine GRA8 pour la majorité des sérums et envers GRA7 dans une moindre mesure. L'hypothèse d'un contact passé avec des parasites génétiquement proches de T. gondii comme Hammondia hammondi ou Neospora caninum semble prometteuse et devrait être approfondie.

Outcome and prognostic factors of Pneumocystis jirovecii pneumonia in immunocompromised adults: a prospective observational study.

BACKGROUND: Pneumocystis jirovecii pneumonia (PJP) remains a severe disease associated with high rates of invasive mechanical ventilation (MV) and mortality. The objectives of this study were to assess early risk factors for severe PJP and 90-day mortality, including the broncho-alveolar lavage fluid cytology profiles at diagnosis. METHODS: We prospectively enrolled all patients meeting pre-defined diagnostic criteria for PJP admitted at Nantes university hospital, France, from January 2012 to January 2017. Diagnostic criteria for PJP were typical clinical features with microbiological confirmation of P. jirovecii cysts by direct examination or a positive specific quantitative real-time polymerase chain reaction (PCR) assay. Severe PJP was defined as hypoxemic acute respiratory failure requiring high-flow nasal oxygen with at least 50% FiO2, non-invasive ventilation, or MV. RESULTS: Of 2446 respiratory samples investigated during the study period, 514 from 430 patients were positive for P. jirovecii. Of these 430 patients, 107 met criteria for PJP and were included in the study, 53 (49.5%) patients had severe PJP, including 30 who required MV. All patients were immunocompromised with haematological malignancy ranking first (n = 37, 35%), followed by solid organ transplantation (n = 27, 25%), HIV-infection (n = 21, 20%), systemic diseases (n = 13, 12%), solid tumors (n = 12, 11%) and primary immunodeficiency (n = 6, 8%). By multivariate analysis, factors independently associated with severity were older age (OR, 3.36; 95% CI 1.4-8.5; p < 0.05), a P. jirovecii microscopy-positive result from bronchoalveolar lavage (BAL) (OR, 1.3; 95% CI 1.54-9.3; p < 0.05); and absence of a BAL fluid alveolitis profile (OR, 3.2; 95% CI 1.27-8.8; p < 0.04). The 90-day mortality rate was 27%, increasing to 50% in the severe PJP group. Factors independently associated with 90-day mortality were worse SOFA score on day 1 (OR, 1.05; 95% CI 1.02-1.09; p < 0.001) whereas alveolitis at BAL was protective (OR, 0.79; 95% CI 0.65-0.96; p < 0.05). In the subgroup of HIV-negative patients, similar findings were obtained, then viral co-infection were independently associated with higher 90-day mortality (OR, 1.25; 95% CI 1.02-1.55; p < 0.05). CONCLUSIONS: Older age and P. jirovecii oocysts at microscopic examination of BAL were independently associated with severe PJP. Both initial PJP severity as evaluated by the SOFA score and viral co-infection predicted 90-day mortality. Alveolitis at BAL examination was associated with less severe PJP. The pathophysiological mechanism underlying this observation deserves further investigation.