The early identification of Mycobacterium tuberculosis infection can prevent tuberculosis (TB) transmission. A skin test with a tuberculosis recombinant allergen (Diaskintest) is a new method for identification that has been implemented in Russia. This study was performed to compare the performances of Diaskintest and QuantiFERON-TB Gold (QFT) in adults and children with suspected TB in Moscow, Russia. Adults (n=85) and children (n=96) were tested using Diaskintest and QFT. Concordance and comparative analyses were performed. Diaskintest and QFT were concordant in 84% of adults and 90% of children (overall concordance 87%, κ>0.6, Kc>0.5). The concordance between QFT, Diaskintest, and the final diagnosis was good in adults (86% and 81%, respectively) and moderate in children (77% and 79%, respectively). In adults, QFT had a higher sensitivity for detecting TB than Diaskintest (82% and 68%, respectively); in children, Diaskintest was more sensitive (73% and 65%, respectively). In patients with a confirmed TB diagnosis, negative Diaskintest/QFT results were associated with low disease activity. Combined Diaskintest/QFT results identified TB patients with higher sensitivity and specificity than each test separately. Diaskintest is a low-cost diagnostic tool that shows a test positivity rate similar to QFT and can be used in combination with QFT as an adjunctive test for TB diagnosis.

Background: Despite a reported cardiac injury in patients with new coronavirus infection, the possibility and specifics of genuine viral myocarditis in COVID-19 remains not fully clear. Purpose: To study the presence of SARS-CoV-2 in the myocardium and the morphological properties of myocarditis in patients with severe coronavirus infection (COVID-19). Methods: Autopsy data of eight elderly patients (75.6 ± 7.4 years), four male and four female, with severe new coronavirus infection were studied. The lifetime diagnosis of COVID-19 is based on a positive result of the PCR study. The inclusion criterion was the presence of morphological signs of myocarditis according to the Dallas criteria. A standard histological examination included staining by hematoxylin and eosin, toluidin blue and Van Gieson. An immunohistochemical study was performed using antibodies to CD3, CD 68, CD20, perforin, toll-like receptor (TLR) types 4 and 9. PCR in real-time was performed to determine the viral RNA in the myocardium. Results: All patients had severe bilateral viral pneumonia. In all cases, myocarditis was not clinically diagnosed. Morphological examination of the heart found signs of active lymphocytic myocarditis. PCR identified the SARS-Cov2 RNA in all cases. There were also signs of destructive coronaritis in all cases, thrombovasculitis, lymphocytic pericarditis (in 3 cases) and endocarditis (in 2 cases). The absence of neutrophils confirms the aseptic nature of inflammation. An immunohistochemical study showed the CD3-positive T lymphocytes in the infiltrates. Increased expression of TLR type 4 and less 9 was also detected. Conclusion: Morphological and immunohistochemical evidence of myocarditis in COVID-19 was presented. Lymphocytic infiltrations and positive PCR confirm the viral nature of inflammation. Myocarditis in COVID-19 is also characterized by coronaritis with microvascular thrombosis and associated with lymphocytic endo- and pericarditis.

Tuberculosis (TB) is currently the leading cause of death among bacterial infectious diseases. The spectrum of disease manifestations depends on both host immune responses and the ability of Mycobacterium tuberculosis to resist it. Small non-coding RNAs are known to regulate gene expression; however, their functional role in the relationship of M. tuberculosis with the host is poorly understood. Here, we investigated the effect of small non-coding sRNAs MTS1338 and MTS0997 on M. tuberculosis properties by creating knockout strains. We also assessed the effect of small non-coding RNAs on the survival of wild type and mutant mycobacteria in primary cultures of human alveolar macrophages and the virulence of these strains in a mouse infection model. Wild-type and mutants survived differentially in human alveolar macrophages. Infection of I/St mice with KO M. tuberculosis H37RV strains provided beneficial effects onto major TB phenotypes. We observed attenuated tuberculosis-specific inflammatory responses, including reduced cellular infiltration and decreased granuloma formation in the lungs. Infections caused by KO strains were characterized by significantly lower inflammation of mouse lung tissue and increased survival time of infected animals. Thus, the deletion of MTS0997 and MTS1338 lead to a significant decrease in the virulence of M. tuberculosis.

P-glycoprotein (encoded by the ABCB1 gene) has a dual role in regulating inflammation and reducing chemotherapy efficacy in various diseases, but there are few studies focused on pulmonary TB patients. In this study, our objective was to identify a list of genes that correlate with high and low levels of ABCB1 gene expression in the lungs of pulmonary TB patients with different activity of chronic granulomatous inflammation. We compared gene expression in two groups of samples (with moderate and high activity of tuberculomas) to identify their characteristic gene signatures. Gene expression levels were determined using quantitative PCR in samples of perifocal area of granulomas, which were obtained from 65 patients after surgical intervention. Subsequently, two distinct gene signatures associated with high inflammation activity were identified. The first signature demonstrated increased expression of HIF1a, TGM2, IL6, SOCS3, and STAT3, which correlated with high ABCB1 expression. The second signature was characterized by high expression of TNFa and CD163 and low expression of ABCB1. These results provide insight into various inflammatory mechanisms and association with P-gp gene expression in lung tissue of pulmonary TB patients and will be useful in the development of a host-directed therapy approach to improving the effectiveness of anti-TB treatment.

One of the key requirements for the diagnosis of pulmonary tuberculosis is the identification of M. tuberculosis in tissue. In this paper, we present the advantages of specific fluorescent antibody labelling, combined with laser scanning confocal microscopy (LSCM), for the detection of M. tuberculosis in histological specimens of lung tissues. We demonstrate that the application of LSCM allows: (i) The automatic acquisition of images of the whole slice and, hence, the determination of regions for subsequent analysis; (ii) the acquisition of images of thick (20–40 μm) slices at high resolution; (iii) single bacteria identification; and (iv) 3D reconstruction, in order to obtain additional information about the distribution, size, and morphology of solitary M. tuberculosis; as well as their aggregates and colonies, in various regions of tuberculosis inflammation. LSCM allows for the discrimination of the non-specific fluorescence of bacteria-like particles and their aggregates presented in histological lung samples, from the specific fluorescence of labelled M. tuberculosis, using spectrum emission analysis. The applied method was effective in the identification of M. tuberculosis in lung histological samples with weak Ziehl–Neelsen staining. Altogether, combining immunofluorescent labelling with the application of LSCM visualization significantly increases the effectiveness of M. tuberculosis detection.

The objective: to analyze the effectiveness of etiological verification of pulmonary mycobacteriosis when using various biological materials at different diagnostic stages.Subjects and Methods. In Center for Diagnosis and Rehabilitation of Respiratory Diseases, CTRI, the results of stage-by-stage examinations of 142 patients (from 2018 to 2022) were analyzed. A retrospective, prospective, cohort, open study was conducted. Inclusion criteria: pulmonary mycobacteriosis etiologically verified by comprehensive microbiological examinations (molecular genetic and cultural tests) (with retrospective analysis after all stages of examination). Exclusion criteria: HIV infection. 115 women and 27 men were enrolled in the study, the age ranged from 21 to 86 years, the mean age was 57,9 years.All patients referred to CTRI for examination due to newly detected changes in the lungs (bronchiectasis, focal changes, and cavities). For etiological verification of the diagnosis, microbiological sputum testing was performed (Stage 1 of the examination); when negative results were obtained, bronchoscopy was prescribed and bronchobiopsies were used for microbiological and molecular genetic diagnostics – Stage 2. In case of negative results of Stage 2, the patient was recommended to undergo a diagnostic resection of the lung – Stage 3 of the examination. At all stages, specimens were sent for comprehensive microbiological testing: fluorescent microscopy to detect acid-fact mycobacteria, real-time polymerase chain reaction (PCR-RV) to detect NTBM DNA. Identification of NTBMB was carried out by molecular genetic methods (PCR for the presence of MTB DNA/NTBM (SYNTOL, Russia), and on DNA strips (GenoType Mycobacterium CM\AS Hain Livescience, Germany)). Specimens were cultured on a liquid medium in the ВАСТЕС MGIT960 (BD, USA).The diagnosis of mycobacteriosis was established in accordance with the diagnostic criteria proposed in the guidelines of the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA) (2020): detection of NTBM in 2 sputum samples or in 1 sample of bronchobiopsy specimens or in 1 surgical specimens [15].The studied data were entered to the Microsoft Office Excel sheet (Microsoft, USA) for statistical processing; the level of statistical significance of differences was taken as 0.05.Results. It was found that slow-growing NTBM were identified as etiologically significant in 93.0%, of which 78.1% was M. avium, fast-growing NTBM were represented only by M. abscessus, 7% of observations. During X-ray examination, the bronchiectatic form – 52.1% (74/142) was detected more often compared to the abdominal – 30.9% (44/142) and focal forms – 16.9% (24/142) (p<0.001). When verifying mycobacteriosis in patients with a negative sputum test – Stage 2 of the examination – the effectiveness was 91.0% (80/88). Regardless of the radiological form of the disease and dissemination of the disease, bronchoscopy revealed pathology of the tracheobronchial tree in 85.2% of cases, mainly in the form of bronchitis with purulent secretions.