The incidence of diseases brought on by resistant strains of micro-organisms, including tuberculosis, is rising globally as a result of the rapid rise in pathogenic micro-organism resistance to antimicrobial treatments. Secondary metabolites with potential for antibacterial activity are produced by cyanobacteria and microalgae. In this study, gram-positive (S. aureus, E. faecalis) and gram-negative (K. pneumoniae, A. baumannii, P. aeruginosa) bacteria were isolated from pulmonary tuberculosis patients receiving long-term antituberculosis therapy. The antimicrobial potential of extracts from the cyanobacteria Leptolyngbya cf. ectocarpi, Planktothrix agardhii, Arthrospira platensis, Rohotiella mixta sp. nov., Nanofrustulum shiloi, and Tetraselmis (Platymonas) viridis Rouchijajnen was evaluated. On mouse splenocytes and peritoneal macrophages, extracts of cyanobacteria and microalgae had inhibitory effects. In vitro studies have shown that cyanobacteria and microalgae extracts suppress the growth of bacteria and mycobacteria. At the same time, it has been demonstrated that cyanobacterial and microalgal extracts can encourage bacterial growth in a test tube. Additionally, the enhanced fucoxanthin fraction significantly reduced the development of bacteria in vitro. In a mouse experiment to simulate tuberculosis, the mycobacterial load in internal organs was considerably decreased by fucoxanthin. According to the information gathered, cyanobacteria and microalgae are potential sources of antibacterial compounds that can be used in the manufacturing of pharmaceutical raw materials.

Microalgae are a source of carotenoids, phycocyanin, phenol, amino acids, polyunsaturated fatty acids, sulfated polysaccharides, pigments, and other bioactive molecules with antimicrobial, antioxidant, antiviral, antitumor, anti-inflammatory, and fat-burning properties. The increasing incidence of infectious processes, including tuberculosis, caused by antimicrobial resistant strains of microorganisms necessitates the search for alternative sources of compounds with antimicrobial activity, including microalgae. In this study, the antimicrobial properties of marine and freshwater microalgae extracts were evaluated against Gram-positive (Staphylococcus aureus, Enterococcus faecalis, and Streptococcus pyogenes) and Gram-negative (Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa), Mycobacterium tuberculosis strain H37Rv and Mycobacterium smegmatis. Water, dimethyl sulfoxide, and ethanol were used as extractants. The obtained microalgae extract exhibited cytotoxicity against splenocytes and, to a lesser extent, against peritoneal macrophages of CBA mice. The bacteriostatic effect of the microalgae extracts against bacteria and mycobacteria was demonstrated by MTT test. In addition, activation of bacterial and mycobacterial growth was observed in a number of cases with high levels of microalgae extracts in the medium. In an expression model of tuberculosis in mice, a decrease in mycobacterial load in the lungs and spleen was observed. Thus, microalgae have moderate to weak antimicrobial activity.

Objective. To investigate the bacterial and fungal microbiota of the lower respiratory tract in hospitalized patients with tuberculosis and HIV coinfection. Materials and Methods. A total of 378 sputum samples from 147 patients at the Novosibirsk Tuberculosis Research Institute (Ministry of Health of the Russian Federation) were collected and analyzed between 2021 and 2024. Sputum samples were obtained according to standardized protocols to minimize contamination with upper respiratory tract microflora and ensure representativeness of the lower respiratory tract biota. Samples were cultured on selective medium. Microbial identification was performed by MALDItof mass spectrometry using a Microflex instrument (Bruker Daltonics, Germany). Statistical analysis was conducted using SPSS software (version 19). Results. To differentiate lower respiratory tract isolates from potential contaminants, paired oropharyngeal (throat) and sputum samples were compared by quantitative culture (CFU/mL) according to established clinical criteria, with adjustments for HIV status. A total of 492 pathogenic and opportunistic microorganisms, belonging to 15 families, were isolated. Fungal microbiota accounted for 44.9% of isolates, predominantly of the family Saccharomycetaceae (mainly C. albicans). Bacterial microbiota constituted 51.1%, represented by Enterobacteriaceae (21.5%), Staphylococcaceae (9.96%), Pasteurellaceae (8.94%, and Pseudomonadaceae (5.69%). The spectrum of microorganisms varied depending on the clinical forms of tuberculosis and the type of drug resistance of mycobacterium. Conclusions. Conclusions.The lower respiratory tract microbiome in patients with active tuberculosis and HIV coinfection is characterized by severe dysbiosis, with a predominance of fungal taxa and Gram-negative facultative anaerobes. This dysbiosis may be associated with factors such as the drug resistance profile of Mycobacterium tuberculosis, disease duration, combination chemotherapy, and the immunosuppressive effects of HIV. These findings highlight the need for a comprehensive approach to the diagnosis and treatment of patients with pulmonary tuberculosis and concomitant HIV infection.

Infectious diseases of farm animals are one of the most pressing problems of current livestock sector. The commonly used specific vaccine prophylaxis is not always effective due to the genetic variability and mutational variability of pathogen antigens ("antigenic drift"), the widespread prevalence of mixed polyetiological infections, heterogeneity of the immune response and reduced immune resistance. Existent specific vaccines are aimed at protecting against a specific pathogen or, in the case of multivalency, against several specific pathogens, and are based on the induction of long-term adaptive, i.e. antigen-specific immunity due to the formation of Tand B-memory cells. In the last decade, it has been established that vaccines containing microorganisms, such as BCG, provide resistance not only to a specific pathogen (for example, in the case of BCG – against M. tuberculosis), but also to a wide range of other pathogens. The main mechanism of this broad heterologous resistance is the increased reactivity of the innate immune system cells, primarily monocytes-macrophages. In response to the primary stimulus ("training"), these cells undergo a number of epigenetic and metabolic rearrangements, become "sensitized" and, when confronted with a second stimulus, the same or another pathogen, provide long-term protection against many viral and bacterial infections. Metabolites of the mevalonate metabolic pathway play an important role in the formation of non-specific or "trained" immunological memory (“trained immunity”, TI). In the present work, the hypothesis of the ability of the farnesyl pyrophosphate synthase inhibitor, aminobisphosphonate (a blocker of the mevalonate pathway at the farnesyl pyrophosphate level), to potentiate BCG-induced TI was verified in in vitro and in vivo experiments. It has been found that the aminobisphosphonate zoledronate induces the TI phenotype in monocytes and causes nonspecific protection against staphylococcal infection in mice. In addition, zoledronate significantly enhances BCG-induced TI, causing a synergistic protective effect. The phenomenon of potentiated TI that we have discovered can form the basis for the development of fundamentally new powerful universal vaccines.