Comparison of microflora isolated from peripheral blood and valvular structures of the heart in patients with infective endocarditis

Abstract

Background. Infective endocarditis (IE) is defined as an infection of a native or prosthetic heart valve, endocardial surface, or permanent cardiac apparatus. Currently, the determination of microorganisms that induce a disease or are involved in the process of pathogenesis by PCR is one of the most modern and rapid tests.The aim. To determine and to compare the spectrum of infectious pathogens in homogenate samples of native heart valves and blood of patients with IE.Materials and methods. Twenty patients with confirmed IE diagnose were examined, admitted for hospitalization at the Research Institute for Complex Issues of Cardiovascular Diseases (Kemerovo, Russia) in 2019. The range of tests used in the study was aimed at detecting such microorganisms as Streptococcus pyogenes, Streptococcus agalactiae, Enterobacter spp., Klebsiella spp., Staphylococcus spp., Streptococcus spp., Bacteroides fragilis, Bacteroides vulgatus, Bacteroides thetaiotaomicron, and Bacteroides ovatus.Results. The study found that 19 samples of heart valves were characterized by the presence of microorganisms from the genus Streptococcus spp., wherein Streptococcus agalactiae was found in two patients. Staphylococcus spp. Were found in 16 samples of valve homogenate. Detection of other pathogens revealed only two cases of Enterobacter spp., Klebsiella spp. When analyzing blood samples from patients with IE, not a single infectious agent was identified. The study revealed a statistically significant difference (p < 0.001) between the incidence of Staphylococcus spp. in samples of valve homogenate and peripheral blood of patients with IE. There was also a statistically significant difference (p < 0.001) for Streptococcus spp. both in samples of valve homogenate and peripheral blood from patients with IE.Conclusion. Molecular genetic research using PCR technologies has low efficiency in detecting the pathogen in the circulating bloodstream, as well as in blood culture. However, the study of homogenized biopsy specimens of the heart valve structures removed during surgery may allow correcting antimicrobial tactics in the early postoperative period of prosthetics.