TCA and SSRI Antidepressants Exert Selection Pressure for Efflux-Dependent Antibiotic Resistance Mechanisms in Escherichia coli

Non-antibiotic compounds associated with humans and the environment can promote horizontal transfer of antimicrobial resistance genes

Horizontal gene transfer plays a key role in the global dissemination of antimicrobial resistance (AMR). AMR genes are often carried on self-transmissible plasmids, which are shared amongst bacteria primarily by conjugation. Antibiotic use has been a well-established driver of the emergence and spread of AMR. However, the impact of commonly used non-antibiotic compounds and environmental pollutants on AMR spread has been largely overlooked. Recent studies found common prescription and over-the-counter drugs, artificial sweeteners, food preservatives, and environmental pollutants, can increase the conjugative transfer of AMR plasmids. The potential mechanisms by which these compounds promote plasmid transmission include increased membrane permeability, upregulation of plasmid transfer genes, formation of reactive oxygen species, and SOS response gene induction. Many questions remain around the impact of most non-antibiotic compounds on AMR plasmid conjugation in clinical isolates and the long-term impact on AMR dissemination. By elucidating the role of routinely used pharmaceuticals, food additives, and pollutants in the dissemination of AMR, action can be taken to mitigate their impact by closely monitoring use and disposal. This review will discuss recent progress on understanding the influence of non-antibiotic compounds on plasmid transmission, the mechanisms by which they promote transfer, and the level of risk they pose.

Core antibiotic resistance genes mediate gut microbiota to intervene in the treatment of major depressive disorder

INTRODUCTION

The relationship between depression and gut microbiota remains unclear, but an important role of gut microbiota has been verified. The relationship between gut microbiota and antibiotic resistance genes (ARGs) may be a potential new explanatory pathway.

METHODS

We collected samples from 63 depressed patients and 30 healthy controls for metagenomic sequencing. The two groups' microbiota characteristics, functional characteristics, and ARG differences were analyzed.

RESULTS

We obtained 30 differential KEGG orthologs (KOs) and their producers in 5 genera and 7 species by HUMAnN3. We found 6 KOs from Weissella_cibaria and Lactobacillus_plantaru are potentially coring functional mechanism of gut microbiota. Different metabolites including sphingolipids, pyrans, prenol lipids, and isoflavonoids also showed significance between MDD and HC. We detected 48 significantly different ARGs: 5 ARGs up-regulated and 43 ARGs down-regulated in MDD compared to HC. Based on Cox model results, Three ARGs significantly affected drug efficacy (ARG29, ARG105, and ARG111). Eggerthella, Weissella, and Lactobacillus were correlated with different core ARGs, which indicated different mechanisms in affecting MDD.

LIMITATIONS

The present study needs to be replicated in different ethnic groups. At the same time, a larger Chinese cohort study and detailed experimental verification are also the key to further discussion.

CONCLUSION

Our findings suggest that ARGs play a role in the interplay between major depressive disorder and gut microbiota. The role of ARGs should be taken into account when understanding the relationship between depression and gut microbiota.

Unveiling gut microbiota's role: Bidirectional regulation of drug transport for improved safety

Drug safety is a paramount concern in the field of drug development, with researchers increasingly focusing on the bidirectional regulation of gut microbiota in this context. The gut microbiota plays a crucial role in maintaining drug safety. It can influence drug transport processes in the body through various mechanisms, thereby modulating their efficacy and toxicity. The main mechanisms include: (1) The gut microbiota directly interacts with drugs, altering their chemical structure to reduce toxicity and enhance efficacy, thereby impacting drug transport mechanisms, drugs can also change the structure and abundance of gut bacteria; (2) bidirectional regulation of intestinal barrier permeability by gut microbiota, promoting the absorption of nontoxic drugs and inhibiting the absorption of toxic components; (3) bidirectional regulation of the expression and activity of transport proteins by gut microbiota, selectively promoting the absorption of effective components or inhibiting the absorption of toxic components. This bidirectional regulatory role enables the gut microbiota to play a key role in maintaining drug balance in the body and reducing adverse reactions. Understanding these regulatory mechanisms sheds light on novel approaches to minimize toxic side effects, enhance drug efficacy, and ultimately improve drug safety. This review systematically examines the bidirectional regulation of gut microbiota in drug transportation from the aforementioned aspects, emphasizing their significance in ensuring drug safety. Furthermore, it offers a prospective outlook from the standpoint of enhancing therapeutic efficacy and reducing drug toxicity, underscoring the importance of further exploration in this research domain. It aims to provide more effective strategies for drug development and treatment.

Computer-aided drug repurposing to tackle antibiotic resistance based on topological data analysis

The progressive emergence of antimicrobial resistance has become a global health problem in need of rapid solution. Research into new antimicrobial drugs is imperative. Drug repositioning, together with computational mathematical prediction models, could be a fast and efficient method of searching for new antibiotics. The aim of this study was to identify compounds with potential antimicrobial capacity against Escherichia coli from US Food and Drug Administration-approved drugs, and the similarity between known drug targets and E. coli proteins using a topological structure-activity data analysis model. This model has been shown to identify molecules with known antibiotic capacity, such as carbapenems and cephalosporins, as well as new molecules that could act as antimicrobials. Topological similarities were also found between E. coli proteins and proteins from different bacterial species such as Mycobacterium tuberculosis, Pseudomonas aeruginosa and Salmonella Typhimurium, which could imply that the selected molecules have a broader spectrum than expected. These molecules include antitumor drugs, antihistamines, lipid-lowering agents, hypoglycemic agents, antidepressants, nucleotides, and nucleosides, among others. The results presented in this study prove the ability of computational mathematical prediction models to predict molecules with potential antimicrobial capacity and/or possible new pharmacological targets of interest in the design of new antibiotics and in the better understanding of antimicrobial resistance.

Gut Microbiota and Microbial Metabolism in Early Risk of Cardiometabolic Disease

Cardiometabolic disease comprises cardiovascular and metabolic dysfunction and underlies the leading causes of morbidity and mortality, both within the United States and worldwide. Commensal microbiota are implicated in the development of cardiometabolic disease. Evidence suggests that the microbiome is relatively variable during infancy and early childhood, becoming more fixed in later childhood and adulthood. Effects of microbiota, both during early development, and in later life, may induce changes in host metabolism that modulate risk mechanisms and predispose toward the development of cardiometabolic disease. In this review, we summarize the factors that influence gut microbiome composition and function during early life and explore how changes in microbiota and microbial metabolism influence host metabolism and cardiometabolic risk throughout life. We highlight limitations in current methodology and approaches and outline state-of-the-art advances, which are improving research and building toward refined diagnosis and treatment options in microbiome-targeted therapies.

The Brain-Gut-Microbiota Interplay in Depression: a key to design innovative therapeutic approaches

Depression is the most prevalent mental disorder in the world associated with huge socio-economic consequences. While depressive-related symptoms are well known, the molecular mechanisms underlying disease pathophysiology and progression remain largely unknown. The gut microbiota (GM) is emerging as a key regulator of the central nervous system homeostasis by exerting fundamental immune and metabolic functions. In turn, the brain influences the intestinal microbial composition through neuroendocrine signals, within the so-called gut microbiota-brain axis. The balance of this bidirectional crosstalk is important to ensure neurogenesis, preserve the integrity of the blood-brain barrier and avoid neuroinflammation. Conversely, dysbiosis and gut permeability negatively affect brain development, behavior, and cognition. Furthermore, although not fully defined yet, changes in the GM composition in depressed patients are reported to influence the pharmacokinetics of common antidepressants by affecting their absorption, metabolism, and activity. Similarly, neuropsychiatric drugs may shape in turn the GM with an impact on the efficacy and toxicity of the pharmacological intervention itself. Consequently, strategies aimed at re-establishing the correct homeostatic gut balance (i.e., prebiotics, probiotics, fecal microbiota transplantation, and dietary interventions) represent an innovative approach to improve the pharmacotherapy of depression. Among these, probiotics and the Mediterranean diet, alone or in combination with the standard of care, hold promise for clinical application. Therefore, the disclosure of the intricate network between GM and depression will give precious insights for innovative diagnostic and therapeutic approaches towards depression, with profound implications for drug development and clinical practice.

Antimicrobial activity of antidepressants on normal gut microbiota: Results of the in vitro study

Currently, there is little published data on the effects of antidepressants on normal gut microbiota and the consequences of such effects on treatment outcomes. The aim of the study: was to evaluate the growth kinetics of normal human gut microorganisms with antidepressants most common in routine clinical practice. Materials and methods: Research objects were species of microorganisms representing normal gut microbiota: Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Candida albicans ATCC 24433, Bifidobacterium 791, Enterococcus faecalis ATCC 29212, Lactobacillus rhamnosus ATCC 53103. All microorganisms were cultivated in Schaedler broth (HiMedia) under aerobic/anaerobic conditions. The active substances of all studied antidepressants (fluvoxamine, fluoxetine, escitalopram, duloxetine, venlafaxine, mirtazapine) were extracted from ground preparations by dimethyl sulfoxide and centrifuged. Each solution of antidepressants was added to a Schaedler broth containing a certain microorganism's strain and diluted to final concentrations-200 μg/ml, 500 μg/ml, and 700 μg/ml. For a quantitative assessment of the effect, the specific growth rates (μ, h-1) of microorganisms were calculated as the slope of the initial part of the growth curve in coordinates (lnA, t). To evaluate the antidepressant effects on representatives of the normal microbiota in vitro, the following parameters were chosen: specific growth rate and IC50. Results: All antidepressants had an inhibitory effect on the growth of all studied microorganisms. Fluvoxamine and venlafaxine had the least effect on the growth activity of all studied microorganisms. Fluoxetine showed a pronounced effect on growth activity against E. coli, E. feacalis, S. aureus, and the least effect against C. albicans. Escitalopram had a greater effect on the growth rate of E. coli, E. feacalis, B. bifidum, L. rhamnosus, and C. albicans, which puts it among the leaders in terms of its effect on the growth activity of the microorganisms we studied. Mirtazapine, according to the results of our experiment, showed the greatest activity against L. rhamnosus and C. albicans. Conclusions: Our results confirm the effects of antidepressants on the growth activity of the normal gut microbiota individual strains. Further study of the antimicrobial activity of antidepressants may become one of the new directions for optimizing the personalized therapy of patients with depression.