In the present article, the possible mitigation of the toxic effect of imidacloprid low-concentration chronic exposure on Danio rerio by the probiotic strain Lactobacillus brevis 47f (1 × 10⁸ CFU/g) was examined. It was found that even sublethal concentration (2500 µg/L) could lead to the death of some fish during the 60-day chronic experiment. However, the use of Lactobacillus brevis 47f partially reduced the toxic effects, resulting in an increased survival rate and a significant reduction of morphohistological lesions in the intestines and kidneys of Danio rerio. The kidneys were found to be the most susceptible organ to toxic exposure, showing significant disturbances. Calculation of the histopathological index, measurement of morphometric parameters, and analysis of principal components revealed the most significant parameters affected by the combined action of imidacloprid and Lactobacillus brevis 47f. This effect of imidacloprid and the probiotic strain had a multidirectional influence on various pro/anti-inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-8). Therefore, the results suggest the possibility of further studying the probiotic strain Lactobacillus brevis 47f as a strain that reduces the toxic effects of xenobiotics. Additionally, the study established the possibility of using imidacloprid as a model toxicant to assess the detoxification ability of probiotics on the kidney and gastrointestinal tract of fish.

In this study, the results of evaluating the acute toxicity of Bisphenol A on Danio rerio are presented, encompassing peripheral blood parameters, the composition of hematopoietic cells of erythroid and myeloid lines in the head kidney, and data from histological studies. The LC50 values of Bisphenol A for adult zebrafish individuals for 12, 24, and 48–96 h were determined, which were 18.04, 7.55, and 6.22 mg/L, respectively. The study includes data on the morphology and quantitative frequency of specific cells in the hematopoietic tissue of the head kidney, along with the consideration of adaptive mechanisms in hematopoiesis under BPA exposure. The application of polynomial regression analysis to reveal the concentration–effect relationship for some hematological and histological parameters was demonstrated. Significant increases in the frequency of erythrocyte nuclear abnormalities were observed at BPA concentrations of 6 and 8 mg/L, which indicates a genotoxic effect. BPA’s impact on fish peripheral blood parameters manifested as an increase in the number of erythrocytes (RBC) and immature erythrocytes, as well as a decrease in the number of lymphocytes. The most notable pathological changes in the head kidney’s hematopoietic tissue included circulatory disturbances and the formation of inflammation/degradation foci, as confirmed by histopathologic indices. At BPA concentrations of 2 and 4 mg/L, the observed changes were compensated for by hematopoietic adaptation mechanisms; however, at concentrations of 6 and 8 mg/L, acute systemic toxicity was evident.

The emergence and spread of drug-resistant Mycobacterium tuberculosis strains (including MDR, XDR, and TDR) force scientists worldwide to search for new anti-tuberculosis drugs. We have previously reported a number of imidazo[1,2-b][1,2,4,5]tetrazines – putative inhibitors of mycobacterial eukaryotic-type serine-threonine protein-kinases, active against M. tuberculosis. Whole genomic sequences of spontaneous drug-resistant M. smegmatis mutants revealed four genes possibly involved in imidazo[1,2-b][1,2,4,5]tetrazines resistance; however, the exact mechanism of resistance remain unknown. We used different approaches (construction of targeted mutants, overexpression of the wild-type (w.t.) and mutant genes, and gene-expression studies) to assess the role of the previously identified mutations. We show that mutations in MSMEG_1380 gene lead to overexpression of the mmpS5-mmpL5 operon in M. smegmatis, thus providing resistance to imidazo[1,2-b][1,2,4,5]tetrazines by increased efflux through the MmpS5-MmpL5 system, similarly to the mechanisms of resistance described for M. tuberculosis and M. abscessus. Mycobacterial MmpS5-MmpL5 transporters should be considered as an MDR-efflux system and they should be taken into account at early stages of anti-tuberculosis drug development.

Soil health is a critical determinant of agricultural productivity and environmental sustainability. Traditional assessment methods often fail to provide a comprehensive understanding of soil microbial communities and their functions. This study addresses this challenge by employing metagenomic techniques to assess the functionality of soil microbiomes in Russian black soil, renowned for its high fertility. We utilized shotgun metagenomic sequencing to analyze soil samples from Western Siberia subjected to different degrees of agro-soil disturbance. We identified functional genes involved in carbon (accA, argG, acsA, mphE, miaB), phosphorus (phoB, ppa, pstB, pnp, phnJ), and nitrogen (queC, amiF, pyrG, guaA, guaB, napA) metabolic pathways and associated with changes in microbial diversity, in general, and higher representation of certain bacterial species—Bradyrhizobium spp. The results demonstrated significant differences in microbial composition and functional potential between tillage treatments. No-Till technology and conventional tillage practices promoted beneficial microbial communities and enhanced soil health compared to long-term fallow soil. This work underscores the potential of metagenomic analysis in providing a comprehensive understanding of soil health, marking a significant advancement in the field.

Obesity, along with metabolic disorders such as dyslipidemia and insulin resistance, increases the risk of cardiovascular disease, diabetes, various cancers, and other non-communicable diseases, thereby contributing to higher mortality rates. The intestinal microbiome plays a crucial role in maintaining homeostasis and influencing human metabolism. This study enrolled 82 young obese individuals, who were stratified into groups with or without metabolic disturbances. No significant differences in the alpha or beta diversity of the microbiota were observed among the groups. Insulin resistance was characterized by an increase in the number of Adlercreutzia and Dialister as well as a decrease in Collinsella, Coprococcus and Clostridiales. The dyslipidemia and dyslipidemia+insulin resistance groups had no significant differences in the gut microbiota. Dietary patterns also influenced microbial composition, with high protein intake increasing Leuconostoc and Akkermansia, and high fiber intake boosting Lactobacillus and Streptococcus. The genus Erwinia was associated with increases in visceral fat and serum glucose as well as a decrease in high-density lipoprotein cholesterol. Our findings highlight a significant association between gut microbiota composition and metabolic disturbances in young obese individuals, and they suggest that dietary modifications may promote a healthy microbiome and reduce the risk of developing metabolic disorders.

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is a global burden, responsible for over 1 million deaths annually. The emergence and spread of drug-resistant M. tuberculosis strains (MDR-, XDR- and TDR-TB) is the main challenge in global TB-control, requiring the development of novel drugs acting on new biotargets, thus able to overcome the drug-resistance. Tryptanthrin is a natural alkaloid, with great therapeutic potential due to its simple way of synthesis and wide spectrum of biological activities including high bactericidal activity on both drug-susceptible and MDR M. tuberculosis strains. InhA was suggested as the target of tryptanthrins by in silico modeling, making it a promising alternative to isoniazid, able to overcome drug resistance provided by katG mutations. However, neither the mechanism of action of tryptanthrin nor the mechanism of resistance to tryptanthrins was ever confirmed in vitro. We show that the MmpS5-MmpL5 efflux system is able to provide resistance to tryptanthrins using an in-house test-system. Comparative genomic analysis of spontaneous tryptanthrin-resistant M. smegmatis mutants showed that mutations in MSMEG_1963 (EmbR transcriptional regulator) lead to a high-level resistance, while those in MSMEG_5597 (TetR transcriptional regulator) to a low-level one. Mutations in an MFS transporter gene (MSMEG_4427) were also observed, which might be involved in providing a basal level of tryptanthrins-resistance.