Microbial Signature Present in Thrombotic Material of Acute Ischemic Stroke Patients Retrieved by Mechanical Thrombectomy

This study is done to examine the microbiota in thrombi retrieved from the middle cerebral artery after mechanical thrombectomy for symptomatic carotid plaque within 6 h of an acute ischemic stroke. To evaluate their role in atherosclerosis, thrombi were submitted to next-generation sequencing for a bacterial signature. In these studies, we are describing the types of bacteria found in thrombus samples that are associated with stroke. The microbial composition of all samples was compared using 16S rRNA gene amplicons and next-generation sequencing. All of the thrombi retrieved for bacterial DNA in qPCR from the fourteen patients who had thrombectomy for ischemic stroke were positive. The 14 thrombus samples had the majority of bacteria: Staphylococcus aureus and Staphylococcus pneumoniae, Bacillus cereus, Lactobacillus, and 30 other microorganisms were found in thrombus associated with stroke. The microbes present in thrombus also play a role in the formation of plaque, and bacteria have direct mechanisms such as acidification and local inflammation of the plaque milieu with Lactobacillus, biofilm dispersion leading to inflammation with Pseudomonas fluorescens or enterococci, or indirect mechanisms such as Toll-2-like signalling by the gut microbiota that could all lead to thromboembolic events and cause stroke. More research into the role of bacteria in thrombus formation in stroke pathophysiology and prognosis is warranted.