Background. If infective endocarditis (IE) is suspected, the determination of the etiology is of fundamental importance for the verification of the disease and the appointment of effective therapy. Microbiological diagnostic features are important, but they often need to be supplemented by culture-independent studies of pathological agents. Aim. To investigate of the diagnostic advantage and value of quantitative analysis of molecular biological methods (polymerase chain reaction - PCR, sequencing) in addition to microbiological examination of whole venous blood in IE. Materials and methods. We examined 124 patients with suspected or significant IE (DUKE 2015) hospitalized in the Vinogradov City Clinical Hospital (2015-2021). All patients underwent parallel microbiological (cultural) and molecular biological (PCR or PCR followed by sequencing) examination of venous whole blood samples. Results. The introduction of an early parallel PCR study into the algorithm for the etiological diagnosis of IE made it possible to obtain an additional advantage in 43/124 (34.7%) patients, which made it possible to exclude unreliable results in the determination of CoNS skin commensals and pathogens atypical for IE or contamination and identify the true pathogens, and also for the first time to isolate the etiopathogenetic pathogen with a negative microbiological study. It was shown that in IE associated with CoNS, the association with the disease was confirmed by PCR in 21.4% (3/14) and refuted in 71.4% (10/14). The coincidence of the results of microbiological and PCR studies of blood samples was obtained only in 35/95 (36.8%). Positive results of PCR analysis of blood of biological material with negative results of culture were obtained in 22/51 (43.1%), of which 2/22 (9.0%) were able to confirm the presence of Bartonella spp DNA. The presented complex algorithm made it possible to significantly increase the possibility of intravital identification of the pathogen in the blood from 58.9 to 76.6%. IE with unknown etiology was present in 29/124 (23.4%) patients. A parallel PCR study allowed timely correction of antibiotic therapy in 43/124 (34.7%) patients. Conclusion. Expansion of indications for the use of PCR studies, primarily whole venous blood samples, is justified, not only in IE with negative results of microbiological examination, but also as a control method for the reliability of the results of traditional (cultural) diagnostic methods.

A clinical observation of the treatment non-compliance consequences with clinical guidelines and principles of empirical therapy selection in a female patient with intravenous drug abuse, viral hepatitis C and HIV infection, with a history of a COVID-19 and the development of uncontrolled staphylococcal infective endocarditis (IE) of the tricuspid valve, complicated recurrence of early prosthetic IE is presented. Successful treatment was achieved only by a combination of tricuspid valve replacement and the appointment of etiotropic therapy for S. aureus (MSSA). The typical clinical scenario was not accompanied by the choice of adequate empirical antibiotic therapy, despite the high suspicion of association with MSSA, which determined the complicated course of IE. Only the polymerase chain reaction of the heart valve tissue played a key role in the etiological diagnosis. The use of valve tissue polymerase chain reaction in addition to traditional microbiological methods is a valuable diagnostic study.

Chickenpox is a common disease leading to a large number of clinical manifestations, ranging from mild spontaneously resolving forms to severe complicated cases requiring hospitalization and parenteral therapy. Despite the fact that this infection is benign in the majority of cases, it can lead to disseminated life-threatening processes in pregnant women and unimmunized newborns infected during the perinatal period, as well as it can cause intrauterine death and fetal abnormalities.Currently, there are no unified therapeutic approaches in the management of pregnant women with chickenpox. The nature and severity of infection in children depends on the moment of infection (before or after birth, intrapartum), the immune status of the mother against the human herpesvirus type 3 (HHV-3), the gestational age of the fetus and the presence of concomitant conditions.

BACKGROUND. The number of organ transplantation surgeries is growing every year, including heart transplantion. The full spectrum of infections in heart transplant recipients is not well understood. One of the infectious agents that is particularly difficult to recognize is Toxoplasma gondii (T. gondii). AIM: This work determines the informative value of detecting laboratory markers of toxoplasmosis in patients after heart transplantation to identify active forms of invasion. MATERIALS AND METHODS: This investigation studied 121 heart recipients (95 men and 26 women) at different times after transplantation (several days to 12 years). Markers of Toxoplasma invasion were determined in blood sera, namely antibodies of the IgG, IgM, and IgA classes to T. gondii, avidity index of IgG antibodies to T. gondii, and DNA of the pathogen. RESULTS: In 60 patients (49.64.5%) after heart transplantation, markers of Toxoplasma invasion were identified. In 20 (16.53.6%) cases, markers of active invasion were revealed, namely IgM and IgA antibodies to T. gondii in six and 11 patients, respectively, low-grade IgG antibodies to T. gondii in three patients, and DNA of the pathogen in two cases. Based on the totality of studies, it was determined that the disease activity in 75% of cases was due to its reactivation, whereas in the other cases, it was a recent infection. Laboratory signs of toxoplasmosis reactivation occurred mainly during the first year after transplantation, which was probably associated with the intensity of immunosuppressive therapy. CONCLUSIONS: It was revealed that the most compelling studies indicating early signs of toxoplasmosis reactivation include detection of IgA antibodies to T. gondii and DNA of the pathogen. Further joint research is required by clinicians, epidemiologists, and laboratory diagnostics specialists to study the aspects of toxoplasmosis and disease diagnostics and preventionin patients after heart transplantation.

In this article, we discuss some aspects of investigating characteristics of infections caused by Human betaherpesvirus 6A/B (HHV-6A/B) and report a case of laboratory confirmed chromosomally integrated HHV-6B (iciHHV-6B) in a 35-year-old woman with herpesvirus infection and secondary immunodeficiency of unknown origin. We have also described an algorithm for the diagnosis and management of patients with positive iciHHV-6A/B status. Key words: HHV-6-infection, diagnostics, human betaherpesvirus 6B, human herpesvirus 6B, chromosomal integration, inheritance, iciHHV-6B, algorithm

The outbreak of shigellosis caused by Shigella. flexneri 2a which affected a total of 42 persons was revealed by epidemiological analysis and microbiological testing in a nursing home for disabled children with a severe pathology of the nervous system. At the same time, four fatal cases among children were registered. The main purpose of our study was to perform an enhanced investigation to find potentially novel etiological agent among affected persons especially in cases with fatal outcome. We applied a broad range of commercial kits based on the nucleic acid amplification techniques as well as bacteriological methods for etiological diagnosis. Additionally, several S. flexneri 2a isolates and revealed bacterial pathogens were subjected to pulsed-field gel electrophoresis (PFGE) and Whole Genome Sequencing (WGS) for expanded genetic characterization as well as demonstration of their clonality and the presents/absence of unusual pathogenic determinants. Genetic relationship between viral pathogens was characterized by Sanger sequencing of phylogenetically informative regions. Epidemiological data and lab testing allowed considering the generalized herpes simplex virus type 1 infection (HSV-1) to be a possible cause of fatal cases.

Objectives: Myalgic encephalomyelitis (ME) is a polymorphic clinical entity. In some patients, chronic infection with Epstein–Barr virus (EBV), human herpesvirus 6 (HHV-6), and human herpesvirus 7 (HHV-7) is regarded as an important pathogenetic factor that contributes to chronic neuroinflammation. We determined a relationship between EBV, HHV-6 and HHV-7 viral load in the saliva and serum levels of pro-inflammatory cytokines (IFNalpha, IFNgamma, IL-1, IL-2) in a group of ME patients.