A Novel Approach for Detecting Unique Variations among Infectious Bacterial Species in Endocarditic Cardiac Valve Vegetation

Abstract

Infectious endocarditis (IE) remains one of the deadliest heart diseases with a high death rate, generally following thrombo-embolic events. Today, therapy is based on surgery and antibiotic therapy. When thromboembolic complications in IE patients persist, this is often due to our lack of knowledge regarding the pathophysiological development and organization of cells in the vegetation, most notably the primordial role of platelets and further triggered hemostasis, which is related to the diversity of infectious microorganisms involved. Our objective was to study the organization of IE vegetations due to different bacteria species in order to understand the related pathophysiological mechanism of vegetation development. We present an approach for ultrastructural analysis of whole-infected heart valve tissue based on scanning electron microscopy and energy-dispersive X-ray spectroscopy. Our approach allowed us to detect differences in cell organization between the analyzed vegetations and revealed a distinct chemical feature in viridans Streptococci ones. Our results illustrate the benefits that such an approach may bring for guiding therapy, considering the germ involved for each IE patient.

Analysis of Risk Factors and Clinical Indicators in Bloodstream Infections Among Patients with Hematological Malignancy

“… 22 Platelets have a direct antibacterial defense effect by recognizing microbial antigens and secreting antimicrobial peptides and kinocidins, enhancing innate immune effectors (including complement, neutrophils) and adaptive coordinate immunity (APS, T cells, and B cells). 23 However, in our study, PLT levels decreased in the blood culture-positive group compared with the blood culture-negative group with an AUC of 0.5803 to differentiate these two groups, and the specificity was too low, which needs further research.…”

Scanning Electron Microscope: A New Potential Tool to Replace Gram Staining for Microbe Identification in Blood Cultures

“…Thus, SEM could advantageously replace optical microscopes and Gram staining in the preliminary identification of bacteria in blood cultures or other body fluids. We have already developed other applications for these SEMs in the rapid detection of respiratory viruses [31], rapid antibiotic susceptibility testing of bacteria [32], detection of bacteria in endocarditic cardiac valve vegetations [33], and identification of several parasites. These various uses of SEM will shift the paradigm of the early diagnosis of infectious diseases, especially in critical cases that have a direct effect on the management of bloodstream infections, the treatment choice, and the patients' prognosis [15,34,35].…”

Native valve, prosthetic valve, and cardiac device-related infective endocarditis: A review and update on current innovative diagnostic and therapeutic strategies

“…Transcatheter interventions were (Schwarz et al, 2022). (B) SEM image visualizing bacteria including a platelet-containing fibrin network (Hannachi et al, 2020). (C) Three-dimensional reconstruction of phagocytic cells (green) infected by bacteria (yellow) using FIB-SEM (Oberbach et al, 2017).…”