Integrated 16S rRNA Gene Sequencing and LC-MS Analysis Revealed the Interplay Between Gut Microbiota and Plasma Metabolites in Rats With Ischemic Stroke.

Gut microbiome and plasma metabolome serve a role in the pathogenesis of ischemic stroke (IS). However, the relationship between the microbiota and metabolites remains unclear. This study aimed to reveal the specific asso-ciation between the microbiota and the metabolites in IS using integrated 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MS) analysis. Male Sprague Dawley (SD) rats were divided into three groups: normal group (n = 8, Normal), model group (n = 9, IS), and sham-operated group (n = 8, Sham). Rats in the IS group were induced by middle cerebral artery occlusion (MCAO), and rats in the Sham group received an initial anesthesia and neck incision only. A neurological function test and 2,3,5-triphenyltetrazolium chloride (TTC) staining were used to assess the IS rat model. Then, the plasma samples were analyzed using untargeted LC-MS. The cecum samples were collected and analyzed using 16S rRNA sequencing. Pearson correlation analysis was performed to explore the association between the gut microbiota and the plasma metabolites. The 16S rRNA sequencing showed that the composition and diversity of the microbiota in the IS and control rats were significantly different. Compared with the Sham group, the abundance of the Firmicutes phylum was decreased, whereas Proteobacteria and Deferribacteres were increased in the IS group. Ruminococcus_sp_15975 and Lachnospiraceae_UCG_001 might be considered as biomarkers for the IS and Sham groups, respectively. LC-MS analysis revealed that many metabolites, such as L-leucine, L-valine, and L-phenylalanine, displayed different patterns between the IS and Sham groups. Pathway analysis indicated that these metabolites were mainly involved in mineral absorption and cholinergic synapse. Furthermore, integrated analysis correlated IS-related microbes with metabolites. For example, Proteobacteria were positively correlated with L-phenylalanine, while they were negatively correlated with eicosapentaenoic acid (EPA). Our results provided evidence of the relationship between the gut microbiome and plasma metabolome in IS, suggesting that these microflora-related metabolites might serve as potential diagnostic and therapeutic markers.

An unusual ischaemic presentation of thrombosed intracranial mycotic aneurysm with subsequent subarachnoid haemorrhage.

We present an unusual case of acute ischaemic stroke secondary to thrombosed mycotic aneurysm with subsequent early aneurysmal rupture and subarachnoid haemorrhage, successfully treated with endovascular coil embolisation of the thrombosed segment. Imaging correlates are presented demonstrating successful endovascular management despite vessel occlusion precluding angiographic visualisation of the aneurysmal segment. Imaging and clinical follow-up is provided demonstrating durable occlusion and excellent clinical outcome with full functional recovery.

Candida parapsilosis endocarditis in an intravenous drug abuser: an autopsy report.

Candida parapsilosis is a rare cause of endocarditis, which is seen to affect the native valves in patients who are known intravenous drug abusers or following contamination during surgery for prosthetic valves. We discuss a unique constellation of autopsy findings in a 35-year-old chronic opium abuser who presented with left-sided weakness followed by low-grade fever. He was diagnosed to have C. parapsilosis native valve endocarditis with septic emboli involving the myocardial vessels, left middle cerebral artery, spleen, and common iliac artery. In addition, autopsy highlighted a right basal ganglia infarct, focal segmental glomerulonephritis, and talc granulomatosis in the lungs and liver.

Successful coil embolization of a ruptured mycotic aneurysm that developed three days after septic embolic infarction: Case report and review of the literature.

BACKGROUND: Infectious intracranial aneurysms (IIAs) are rare entities and are often associated with septic embolus from infectious endocarditis. They may develop rapidly and carry a higher risk of rupture and mortality compared to noninfectious aneurysms. However, the development and rupture of an IIA within 48h in a patient with septic infarction patient is exceedingly rare. CASE DESCRIPTION: In this report, we describe a 25-year-old male who presented with left-sided hemiparesis and dysarthria from septic embolus to the right middle cerebral artery. Thirty-nine hours after presentation, he became encephalopathic following a witnessed seizure. Angiography demonstrated a new, ruptured aneurysm, which was successfully treated with endovascular coil embolization. Our study documents the first report of coil embolization in a rapidly developed infectious aneurysm. CONCLUSIONS: Importantly, this case demonstrates that septic infarction may precede and herald IIA development and rupture. If IIA is detected due to rupture, coil embolization can be a safe and effective therapy.

Depletion of Cultivatable Gut Microbiota by Broad-Spectrum Antibiotic Pretreatment Worsens Outcome After Murine Stroke.

BACKGROUND AND PURPOSE: Antibiotics disturbing microbiota are often used in treatment of poststroke infections. A bidirectional brain-gut microbiota axis was recently suggested as a modulator of nervous system diseases. We hypothesized that gut microbiota may be an important player in the course of stroke. METHODS: We investigated the outcome of focal cerebral ischemia in C57BL/6J mice after an 8-week decontamination with quintuple broad-spectrum antibiotic cocktail. These microbiota-depleted animals were subjected to 60 minutes middle cerebral artery occlusion or sham operation. Infarct volume was measured using magnetic resonance imaging, and mice were monitored clinically throughout the whole experiment. At the end point, tissues were preserved for further analysis, comprising histology and immunologic investigations using flow cytometry. RESULTS: We found significantly decreased survival in the middle cerebral artery occlusion microbiota-depleted mice when the antibiotic cocktail was stopped 3 days before surgery (compared with middle cerebral artery occlusion specific pathogen-free and sham-operated microbiota-depleted mice). Moreover, all microbiota-depleted animals in which antibiotic treatment was terminated developed severe acute colitis. This phenotype was rescued by continuous antibiotic treatment or colonization with specific pathogen-free microbiota before surgery. Further, infarct volumes on day one did not differ between any of the experimental groups. CONCLUSIONS: Conventional microbiota ensures intestinal protection in the mouse model of experimental stroke and prevents development of acute and severe colitis in microbiota-depleted mice not given antibiotic protection after cerebral ischemia. Our experiments raise the clinically important question as to whether microbial colonization or specific microbiota are crucial for stroke outcome.

Commensal microbiota affects ischemic stroke outcome by regulating intestinal γδ T cells.

Commensal gut bacteria impact the host immune system and can influence disease processes in several organs, including the brain. However, it remains unclear whether the microbiota has an impact on the outcome of acute brain injury. Here we show that antibiotic-induced alterations in the intestinal flora reduce ischemic brain injury in mice, an effect transmissible by fecal transplants. Intestinal dysbiosis alters immune homeostasis in the small intestine, leading to an increase in regulatory T cells and a reduction in interleukin (IL)-17-positive γδ T cells through altered dendritic cell activity. Dysbiosis suppresses trafficking of effector T cells from the gut to the leptomeninges after stroke. Additionally, IL-10 and IL-17 are required for the neuroprotection afforded by intestinal dysbiosis. The findings reveal a previously unrecognized gut-brain axis and an impact of the intestinal flora and meningeal IL-17(+) γδ T cells on ischemic injury.

Mitral valve repair in active infective endocarditis with cerebral infarction.

A 19-year-old woman, who had a recent extensive cerebral infarction caused by a septic embolization in the left-sided territory of the middle cerebral artery, successfully underwent mitral valve repair for severe mitral regurgitation caused by active infective endocarditis, 24 h after the onset of stroke. Anticoagulation during cardiopulmonary bypass was maintained with low-dose heparin and additional nafamostat mesilate. She had no further aggravation of the brain complication and recovered well with midterm mitral valve durability.

Combined endovascular and open operative approach for mycotic carotid aneurysm.

Mycotic aneurysms of the extracranial carotid artery are rare and warrant surgical intervention. Management involves open and endovascular approaches. We report the case of a 67-year-old woman with an Escherichia coli soft-tissue infection of the right retropharyngeal space and subsequent mycotic carotid aneurysm and thrombosis of the internal jugular vein. The patient presented with a pulsatile mass and right middle cerebral artery stroke. Our surgical management involved coil embolization of the aneurysm to provide for vascular control, with resection of the common carotid artery, internal carotid artery, and extracranial carotid artery branches, along with the internal jugular vein.

Necrobacillosis resulting in isolated carotid thrombosis and massive stroke: a unique Lemierre variant?

We describe a healthy, young adult male patient who developed isolated carotid artery thrombosis and occlusion following acute pharyngitis due to Fusobacterium necrophorum. We believe this is the first case of isolated occlusion of internal carotid artery (ICA) with F.necrophorum without associated internal jugular vein (IJV) thrombosis. Lemierre's syndrome (LS) is characterized by a history of recent oropharyngeal infection in previously healthy individuals, clinical or radiological evidence of internal jugular vein thrombosis, and isolation of anaerobic pathogens, mainly F.necrophorum. We discuss literature on this rare, previously unreported, variant of LS.

[Middle cerebral artery ischemic stroke presentation of miliar tuberculosis]. / Infarto de la arteria cerebral media como forma de presentación de la tuberculosis miliar.

Presence of central nervous system by extrapulmonary tuberculosis is an infrequent disease specially among non HIV infected patients, and it is associated with poor prognosis and high mortality rates. We report a case with a middle cerebral artery ischemic strocke as a first symptom of miliar tuberculosis.

Streptococcus oralis as a risk factor for middle cerebral artery thrombosis.

We reported a case of an 8-year-old boy who was presented to the emergency department with left-sided hemiparesis. Computed tomography showed hypodense areas in the territory of the right middle cerebral artery, indicating acute cerebral infarct. Diagnostic evaluation was performed to identify the etiology. On the eighteenth day of hospitalization, cerebrospinal fluid cultures yielded Streptococcus oralis. We hypothesized that the source of the oral pathogen was an abscess belonging to his upper left fourth tooth, which, by a transient bacteremia, had invaded the central nervous system, and skipping the meninges caused local inflammatory arteritis of the carotid artery, leading to cerebral infarction. Sulbactam-ampicillin therapy was initiated for 14 days, and he was discharged with anticoagulation therapy.

[Rhinocerebral mucormycosis]. / Une mucormycose rhinocérébrale.

INTRODUCTION: Mucormycosis is a rare and acute fungal infection which is frequently lethal. The rhinocerebral form is usually seen in diabetics, but other localizations may occur in severely immunocompromised subjects. OBSERVATION: We report the case of a sphenoidal sinusitis associated with a probable cavernous sinus thrombosis and carotid artery thrombosis with middle cerebral artery territory infarction. Diagnosis was made on histological examination following sphenoidotomy. Early medical and surgical treatment led to a good outcome. CONCLUSION: The diagnosis of rhinocerebral mucormycosis should be considered in the clinical setting of necrotic sinusitis and acute neurologic deficit in diabetic patients. Early diagnosis and treatment are crucial factors leading to a good outcome.

Infarto maligno de la arteria cerebral media en una paciente con meningitis bacteriana / Malignant infarct of the middle cerebral artery in a patient with bacterial meningitis

The mortality of acute bacterial meningitis (BM) has remained stable in the last decades in spite of the use of new antibiotics, probably due to vascular complications. We report a 68-year-old woman with BM who had a malignant infarction of left middle cerebral artery territory 72 hours after admission to the hospital. The patient experienced a bad evolution and died four days after admission. The arterial involvement in patients with BM is explained by vasospasm of large arteries and vasculitis of small arteries. The medical treatment of a malignant middle cerebral artery infarct has a high mortality.