Université de Rouen Normandie

Toxoplasmosis, a parasitic infection caused by Toxoplasma gondii, is widely distributed worldwide. Although it generally remains asymptomatic in immunocompetent individuals, it can lead to severe complications in immunocompromised patients, particularly those infected with HIV. These individuals are at increased risk of developing encephalitis, primarily due to the reactivation of a latent infection. Genotyping of T. gondii in humans is an essential tool for studying the epidemiology of this parasitosis. Previous studies have identified three main archetypal (classical) lineages or genotypes: type I, II, and III, as well as strains that show distinct and broader genetic variations. In this study, we report for the first time in Algeria the isolation and genetic characterization of the Africa 4 lineage of Toxoplasma gondii using microsatellites genotyping in an HIV-positive patient. This recently described clonal lineage in animal and human highlights the genetic diversity of T. gondii. This work underscores the need for studies to explore the prevalence and distribution of genotypes in the Maghreb region.

Systematic data about whether photon counting detector CT (PCD-CT) could improve the assessment of native heart valves is lacking. Thus, the aim of this study was to assess the performances of PCD-CT for the evaluation of native heart valves as compared to energy integrating detector CT (EID-CT).

Patients necessitating coronary artery CT were prospectively included (February 2021 to December 2022) to undergo an ECG-gated PCD-CT and EID-CT. A subjective assessment of the sharpness and conspicuity of each of the components of the four valves was performed with a 4-point scale. The number of small structures of the valvular apparati was calculated. The number of calcifications per leaflet and their localization within the thickness of the aortic leaflets were noted. The volume of the calcifications and the full width at mid weight (FWMH) of the aortic valve were calculated.

Thirty-three patients (62 ± 13 years; 88 % men) were included. Conspicuity of aortic, mitral, and pulmonary valvular structures was increased with PCD-CT (all < 0.05) except for the aortic right-non-coronary commissure and the pulmonary right-left commissure (p = 0.06 and p = 0.07). Sharpness was superior for all the borders and the commissures of the aortic and mitral valve (all p < 0.05). More fine structures (nodules, chordae) and calcifications were visible with PCD-CT. The precise localization of the calcifications could be assessed with PCD-CT in most cases (70 %) while the volumes were similar (p = 0.07). FWMH was lower with PCD-CT (1.7(IQ = 1.1) vs 2.5 mm (IQ = 1.3); p < 0.01).

PCD-CT yielded better subjective and objective image quality of native aortic, mitral and pulmonary valves and allowed for more structures to be detected compared to EID-CT. This might result in earlier, improved diagnosis of valve pathologies.

Excessive fructose intake is a growing public health concern, yet many individuals have a limited capacity to absorb typical dietary levels, leading to chronic fructose malabsorption and intestinal spillover. In animal models, this spillover disrupts the gut microbiota, but its impact in humans remains unexplored. We hypothesized that fructose malabsorption-induced dysbiosis contributes to peripheral inflammation, which, together with neuroinflammation, plays a role in mood disorders. This study investigates the link between fructose malabsorption, gut microbiota, and mood disorders in a human cohort, and explores their association with neuroinflammation in a Glut5 knockout (GLUT5_KO) mouse model of fructose-malabsorption. In a human cohort of male healthy volunteers, fructose malabsorption was assessed using a breath hydrogen test, while plasma lipopolysaccharide (LPS), IL8 and TNFα levels and anxiety traits (measured using the State-Trait Anxiety Inventory, STAI) were analyzed. Gut microbiota composition was characterized through 16S rRNA sequencing, and dietary fructose intake was recorded. In the preclinical study, GLUT5_KO male mice, which lack intestinal fructose transport, were fed a 5% fructose diet for four weeks. Behavioral assays assessed anxiety- and depressive-like behaviors, while gut microbiota composition and microglia-associated gene expression were analyzed. Sixty percent of volunteers exhibited fructose malabsorption, along with elevated plasma LPS, IL8 and TNFα levels, increased anxiety traits on the STAI, and distinct gut microbiota alterations, partially linked to fructose intake patterns. The average daily fructose intake was 30 g per individual, with significant variability in dietary sources. In the preclinical model, GLUT5_KO mice on a 5% fructose diet displayed increased anxiety- and depressive-like behaviors, pronounced gut microbiota shifts, and altered expression of microglia-associated genes. These findings highlight the complex interplay between dietary fructose, gut microbiota, low grade inflammation and neuroinflammation in shaping mental health. Chronic fructose malabsorption may contribute to mood disorders through gut dysbiosis and microglia-dependent neuroinflammation, warranting further investigation into dietary interventions.