RESUMO
BACKGROUND: Endograft infection is a rare but extremely dangerous complication of aortic repair (25-100% of mortality). We describe here the first case of Listeria monocytogenes abdominal periaortitis associated with a vascular graft. We also discuss the differential diagnosis of periaortitis and provide a literature review of L. monocytogenes infectious aortitis. CASE PRESENTATION: Nine months after endovascular treatment of an abdominal aortic aneurysm (abdominal stent graft), a 76-year-old man was admitted for severe abdominal pain radiating to the back. Laboratory tests were normal apart from elevated C-reactive protein (CRP). Injected abdominal computed tomography (CT) showed infiltration of the fat tissues around the aortic endoprosthesis and aneurysmal sac expansion; positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro- D-glucose integrated with computed tomography (18F-FDG PET/CT) showed a hypermetabolic mass in contact with the endoprosthesis. Blood cultures were negative. At surgical revision, an infra-renal peri-aortic abscess was evident; post-operative antibiotic therapy with ciprofloxacin and doxycycline was started. Cultures of intraoperative samples were positive for L. monocytogenes. Results were further confirmed by a broad-range polymerase chain reaction (PCR) and next-generation sequencing. Antibiotic treatment was switched to intravenous amoxicillin for 6 weeks. Evolution was uneventful with decrease of inflammatory parameters and regression of the abscess. CONCLUSION: An etiologic bacterial diagnosis before starting antibiotic therapy is paramount; nevertheless, culture-independent methods may provide a microbiological diagnosis in those cases where antimicrobials are empirically used and when cultures remain negative.
Assuntos
Listeria monocytogenes/patogenicidade , Listeriose/tratamento farmacológico , Fibrose Retroperitoneal/microbiologia , Idoso , Antibacterianos/uso terapêutico , Aneurisma da Aorta Abdominal/complicações , Aneurisma da Aorta Abdominal/terapia , Hemocultura , Ciprofloxacina/uso terapêutico , Doxiciclina/uso terapêutico , Fluordesoxiglucose F18 , Humanos , Listeriose/diagnóstico por imagem , Masculino , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Reoperação , Fibrose Retroperitoneal/diagnóstico por imagem , Fibrose Retroperitoneal/tratamento farmacológico , Stents , Tomografia Computadorizada por Raios XRESUMO
Caloric restriction (CR) stimulates development of functional beige fat and extends healthy lifespan. Here we show that compositional and functional changes in the gut microbiota contribute to a number of CR-induced metabolic improvements and promote fat browning. Mechanistically, these effects are linked to a lower expression of the key bacterial enzymes necessary for the lipid A biosynthesis, a critical lipopolysaccharide (LPS) building component. The decreased LPS dictates the tone of the innate immune response during CR, leading to increased eosinophil infiltration and anti-inflammatory macrophage polarization in fat of the CR animals. Genetic and pharmacological suppression of the LPS-TLR4 pathway or transplantation with Tlr4-/- bone-marrow-derived hematopoietic cells increases beige fat development and ameliorates diet-induced fatty liver, while Tlr4-/- or microbiota-depleted mice are resistant to further CR-stimulated metabolic alterations. These data reveal signals critical for our understanding of the microbiota-fat signaling axis during CR and provide potential new anti-obesity therapeutics.