Project description:BackgroundM-bM-^@M-^TDiagnosis and pronostic assessment are challenging in infective endocarditis (IE). To investigate the host response during IE and identify potential biomarkers, we determined the circulating gene expression profile through a whole genome microarray analysis. Methods and ResultsM-bM-^@M-^TA transcriptomic case-control study was performed on blood samples from patients with native valve IE (n=39), excluded IE after an initial suspicion (n=10) at patientM-bM-^@M-^Ys admission, and age-matched healthy controls (n=10). The whole genome microarray analysis showed that patients with IE exhibited a specific transcriptional program with a predominance of gene categories associated with cell activation, innate immune and inflammatory responses. These categories were organized in a dense network from which arose numerous subnetworks including major histocompatibily complex and natural killer cell network, type 1 interferon pathway and intracellular traffic. Quantitative real-time RT-PCR performed on a selection of highly modulated genes showed that the expression of the gene encoding S100 calcium binding protein A11 (S100A11) was significantly increased in patients with IE in comparison with controls (P<0.001) and patients with excluded IE (P<0.05). Interestingly, the upregulated expression of S100A11 gene was more pronounced in staphylococcal IE than in streptococcal IE (P<0.01). These results were confirmed by serum concentrations of the S100A11 protein. Finally, we showed that, in patients with IE, the upregulation of aquaporin-9 gene (AQP9) was significantly related to the occurrence of acute heart failure (P=0.02). ConclusionsM-bM-^@M-^T Using transcriptional signatures of blood samples, we identified S100A11 as a potential diagnostic marker of IE. In addition, the determination of AQP9 may improve the prognostic assessment of IE. The transcriptomic case-control study was performed in 39 consecutive patients with native valve IE (IE group) diagnosed by a multidisciplinary team who applied the modified Duke criteria,12 10 patients admitted for a suspicion of IE but with a final excluded IE diagnosis. Ten IE patients and five controls were arbitrary selected and investigated with microarrays.
Project description:Infective endocarditis is a severe disease caused by the infection of heart valves and endocardium by pathogenic germ. Antimicrobial therapy and surgery remain the basis of treatment, and up to 50% of the patients require surgical replacement of the affected valves to control the infectious source. The objective of this work is to identify the existence of endotypes in a prospective cohort of patients with infective endocarditis. We performed a bulk RNA-seq form peripheral blood to cluster patients according to their transcriptomic profiles at diagnosis and during their follow-up. Clinical data, outcomes and response to surgery were assessed in a cluster-specific manner, in order to identify differences in the pathogenesis that could help to find personalized treatments and improve the outcome.
Project description:Infective endocarditis is a severe disease caused by the infection of heart valves and endocardium by pathogenic germ. Antimicrobial therapy and surgery remain the basis of treatment, and up to 50% of the patients require surgical replacement of the affected valves to control the infectious source. The objective of this work is to identify the existence of endotypes in a prospective cohort of patients with infective endocarditis. We performed a bulk RNA-seq form peripheral blood to cluster patients according to their transcriptomic profiles at diagnosis and during their follow-up. Clinical data, outcomes and response to surgery were assessed in a cluster-specific manner, in order to identify differences in the pathogenesis that could help to find personalized treatments and improve the outcome.
Project description:Granulicatella adiacens is a non-motile, non-spore-forming, facultatively anaerobic Gram-positive coccus. It is part of the normal oral flora but cause serious infections such as infective endocarditis. Many bacterial species produce extracellular vesicles (EVs) as part of normal physiology, but also use it as a virulence strategy. In this study, it was hypothesized that G. adiacens produces EVs that possibly help the species in virulence. Therefore, the objectives were to isolate and characterize EVs produced by these species and to investigate their immune-stimulatory effects. The reference strain G. adiacens CCUG 27809 was cultured on chocolate blood agar for 2 days. From subsequent broth cultures, the EVs were isolated using differential centrifugation and filtration protocol and then observed using scanning electron microscopy. Proteins in the vesicle preparations were identified by nano LC-ESI-MS/MS. The EVs proteomes were analyzed and characterized using different bioinformatics tools. The immune-stimulatory effect of the EVs was studied via ELISA quantification of IL-8, IL-1β and CCL5, major proinflammatory cytokines, produced from stimulated human PBMCs. It was revealed that both G. adiacens and G. elegans produced EVs, ranging in diameter from 30 to 250 nm. Overall, G. adiacens EVs contained 112 proteins. The proteome consist of several ribosomal proteins, DNA associated proteins, binding proteins, and metabolic enzymes. It was also shown that these EVs carry putative virulence factors including moonlighting proteins. These EVs were able to induce the production of IL-8, IL-1β and CCL5 from human PBMCs. The diversity in EVs content indicates that these vesicles may have possible roles in bacterial survival, invasion, host immune modulation as well as infection. Further characterization of the composition and immunogenicity of G. adiacens EVs may provide new insights into virulence mechanisms of this bacterial species.
Project description:Q fever is due to Coxiella burnetii, an obligate intracellular bacterium. We investigated the mechanism of establishment of chronic form of the Q fever that mainlym anifested by endocarditis. We showed that patients with acute Q fever and valvulopathy, who have the higher risk to develop an endocarditis, exhibited high levels of circulating apoptotic cells. We further investigated the effect of the uptake of dead cells on the intracellular fate of the bacterium and the immune response of monocytes and macrophages.