Effector molecules translocated by the Salmonella pathogenicity island (SPI)1-encoded type 3 secretion system (T3SS) critically contribute to the pathogenesis of human Salmonella infection. They facilitate internalization by non-phagocytic enterocytes rendering the intestinal epithelium an entry site for infection. Their function in vivo has remained ill-defined due to the lack of a suitable animal model that allows visualization of intraepithelial Salmonella. Here, we took advantage of our novel neonatal mouse model and analyzed various bacterial mutants and reporter strains as well as gene deficient mice. Our results demonstrate the critical but redundant role of SopE₂ and SipA for enterocyte invasion, prerequisite for transcriptional stimulation and mucosal translocation in vivo. In contrast, the generation of a replicative intraepithelial endosomal compartment required the cooperative action of SipA and SopE₂ or SipA and SopB but was independent of SopA or host MyD88 signaling. Intraepithelial growth had no critical influence on systemic spread. Our results define the role of SPI1-T3SS effector molecules during enterocyte invasion and intraepithelial proliferation in vivo providing novel insight in the early course of Salmonella infection. Non-typhoidal Salmonella represent a major causative agent of gastroenteritis worldwide. Hallmark of the pathogenesis is their ability to actively invade the intestinal epithelium by virtue of their type 3 secretion system that delivers bacterial virulence factors directly into the host cell cytosol. The role of these virulence factors during enterocyte entry and intraepithelial growth has only been investigated in vitro since the previously established in vivo models in small animals did not allow visualization of intraepithelial Salmonella. However, immortalized cell lines lack the overlaying mucus layer, final cell lineage differentiation, apical-basolateral polarization as well as continuous migration along the crypt villus axis and thus the role of virulence factors during the Salmonella infection in vivo has remained largely undefined. Here, we took advantage of our novel neonatal mouse infection model and for the first time systematically analyzed the importance of Salmonella virulence factors for enterocyte invasion and intraepithelial growth.

Aims Chronic heart failure with reduced ejection fraction remains a major health issue. To date, no reliable biomarker is available to predict reduced left ventricular ejection fraction (LV-EF). We aimed to identify novel circulating biomarkers for reduced left ventricular function using untargeted serum metabolomics in two independent patient cohorts. Methods and results Echocardiography and non-targeted serum metabolomics were conducted in two patient cohorts with varying left ventricular function: (1) 25 patients with type 2 diabetes with established cardiovascular disease or high cardiovascular risk (LV-EF range 20–66%) (discovery cohort) and (2) 37 patients hospitalized for myocardial infarction (LV-EF range 25–60%) (validation cohort). In the discovery cohort, untargeted metabolomics revealed seven metabolites performing better than N-terminal pro-B-type natriuretic peptide in the prediction of impaired left ventricular function shown by LV-EF. For only one of the metabolites, acisoga, the predictive value for LV-EF could be confirmed in the validation cohort (r = −0.37, P = 0.02). In the discovery cohort, acisoga did not only correlate with LV-EF (r = −60, P = 0.0016), but also with global circumferential strain (r = 0.67, P = 0.0003) and global longitudinal strain (r = 0.68, P = 0.0002). Similar results could be detected in the discovery cohort in a 6 month follow-up proofing stability of these results over time. With an area under the curve of 0.86 in the receiver operating characteristic analysis, acisoga discriminated between patients with normal EF and LV-EF < 40%. Multivariate analysis exposed acisoga as independent marker for impairment of LV-EF (Beta = −0.71, P = 0.004). Conclusions We found the polyamine metabolite acisoga to be elevated in patients with impaired LV-EF in two independent cohorts. Our analyses suggest that acisoga may be a valuable biomarker to detect patients with heart failure with reduced ejection fraction.

The intestinal epithelium is the first line of defense against enteric pathogens. Removal of infected cells by exfoliation prevents mucosal translocation and systemic infection in the adult host, but is less commonly observed in the neonatal intestine. Instead, here, we describe non-professional efferocytosis of Salmonella-infected enterocytes by neighboring epithelial cells in the neonatal intestine. Intestinal epithelial stem cell organoid cocultures of neonatal and adult cell monolayers with damaged enterocytes replicated this observation, confirmed the age-dependent ability of intestinal epithelial cells for efferocytosis, and identified the involvement of the “eat-me” signals and adaptors phosphatidylserine and C1q as well as the “eat-me” receptors integrin-αv (CD51) and CD36 in cellular uptake. Consistent with this, massive epithelial cell membrane protrusions and CD36 accumulation at the contact site with apoptotic cells were observed in the infected neonatal host in vivo. Efferocytosis of infected small intestinal enterocytes by neighboring epithelial cells may represent a previously unrecognized mechanism of neonatal antimicrobial host defense to maintain barrier integrity.

Background: Acute myocarditis is a potentially life-threatening cardiac condition and immediate assessment of this disease is imminent. While laboratory tests, electrocardiography or transthoracic echocardiography can provide indirect signs for the presence of acute myocarditis, cardiac magnetic resonance (CMR) imaging enables direct visualisation of myocardial inflammation and confirms the diagnosis. Since there is limited accessibility to CMR, the goal of this study was to evaluate the sensitivity and specificity of an elevation of established biomarkers for the diagnosis of myocarditis and to define a specific rule-out threshold for deferring CMR. Methods: 244 consecutive patients with clinical suspicion of acute myocarditis underwent comprehensive CMR imaging. CMR data and laboratory parameters were retrospectively analysed. Results: Based on the CMR results, the diagnosis of acute myocarditis was confirmed in 72 individuals. Significant differences regarding age, cardiac function and biomarker levels were present between these groups. Receiver operating characteristics analysis revealed high-sensitivity troponin T (hsTNT) with high sensitivity and specificity for the result of the CMR examination. With a negative predictive value of 0.96 and a sensitivity of 0.92, a hsTNT cut-off of 18 pg/mL was defined as a safe rule-out value for suspected myocarditis. Conclusions: CMR imaging is the gold standard for the non-invasive confirmation of acute myocarditis. However, in this cohort, patients with a hsTNT level of ≤18 pg/mL have a very low likelihood of acute myocarditis, suggesting that CMR may not be necessary to exclude the diagnosis.

Background/Objectives: Percutaneous left atrial appendage occlusion (LAAO) has become an alternative to oral anticoagulation in selected patients with atrial fibrillation. The results of transcatheter LAAO were evaluated by conventional cardiac angiography (CCA), fluoroscopy, and 2D and 3D transesophageal echocardiography (TEE). Methods: In 47 consecutive patients (76 ± 8 years), LAAO was performed with the Amplatzer^TM device. CCA and 2D and 3D TEE were performed for LAA measurements. The eccentricity of the device landing zone was assessed by 3D TEE as the ratio of the maximal and minimal diameters. The device size was selected depending on the CCA maximal diameter. The postprocedural device lobe morphology was classified by fluoroscopy as “square” type (sign of undersizing), “tire” type (optimal deformation), and “strawberry” type (sign of oversizing). After 6 months, TEE was repeated to evaluate peri-device leaks (PDLs). Results: The postprocedural device morphology was “square” type in 9 (19%), “tire” type in 28 (60%), and “strawberry” type in 10 patients (21%). After 6 months, peri-device leaks were observed in 11 patients (23%), with the lowest incidence in the “tire”-type group (11%) compared with “square” type (56%) and “strawberry” type (30%) (p = 0.019). The 3D TEE eccentricity index with a cut-off value of ≤1.29 (indicating a more circular morphology) was a very specific predictor for excluding postprocedural device deformation of the “strawberry” type (AUC = 0.689; sensitivity 48.7%, specificity 100%). Conclusions: Undersizing as well as oversizing of the LAA occluder, as characterized by deformation type by fluoroscopy, was associated with postprocedural PDLs. The eccentricity of the LAA landing zone by 3D TEE may indicate inadequate size selection of the Amplatzer^TM device leading to oversizing in patients with a more eccentric LAA.