Repositioning of antidepressant drugs and synergistic effect with ciprofloxacin against multidrug-resistant bacteria

Risk factors for Pseudomonas aeruginosa VIM colonization/infection in the ICU: Case control study

BACKGROUND

Carbapenem-resistant strains of Pseudomonas aeruginosa (CRPA) have become a major healthcare concern in many countries, against which anti-infective strategies are limited and which require adequate infection control interventions. Knowing the different modes of transmission of CRPA in intensive care units (ICUs) would be helpful to adapt the means of prevention.

METHODS

The aim of this retrospective case-control study was conducted between 01/01/2017 and 02/28/2022 to identify the risk factors for the acquisition of CRPA in ICUs.

RESULTS

During the study period, 147 patients were included (49 cases and 98 controls). Among the 49 patients, 31 (63%) acquired CRPA in clusters and 18 (37%) sporadically. An univariate analysis showed that five variables were associated with CRPA acquisition including (i) prior antibiotic prescriptions, (ii) admission to rooms 203 and 207, (iii) severity of illness at admission, and (iv) use of mechanical ventilation. Multivariate analysis identified three factors of CRPA acquisition including admission to room 203 (OR = 29.5 [3.52-247.09]), previous antibiotic therapy (OR = 3.44 [1.02 - 11.76]) and severity of condition at admission (OR = 1.02 [1 - 1.04]).

CONCLUSION

Our study suggests the role of a contaminated environment in the acquisition of CRPA in the ICU, along with antibiotic use.

Improving the treatment of bacterial infections caused by multidrug-resistant bacteria through drug repositioning

Drug repurposing (repositioning) is a dynamically-developing area in the search for effective therapy of infectious diseases. Repositioning existing drugs with a well-known pharmacological and toxicological profile is an attractive method for quickly discovering new therapeutic indications. The off-label use of drugs for infectious diseases requires much less capital and time, and can hasten progress in the development of new antimicrobial drugs, including antibiotics. The use of drug repositioning in searching for new therapeutic options has brought promising results for many viral infectious diseases, such as Ebola, ZIKA, Dengue, and HCV. This review describes the most favorable results for repositioned drugs for the treatment of bacterial infections. It comprises publications from various databases including PubMed and Web of Science published from 2015 to 2023. The following search keywords/strings were used: drug repositioning and/or repurposing and/or antibacterial activity and/or infectious diseases. Treatment options for infections caused by multidrug-resistant bacteria were taken into account, including methicillin-resistant staphylococci, multidrug-resistant Mycobacterium tuberculosis, or carbapenem-resistant bacteria from the Enterobacteriaceae family. It analyses the safety profiles of the included drugs and their synergistic combinations with antibiotics and discusses the potential of antibacterial drugs with antiparasitic, anticancer, antipsychotic effects, and those used in metabolic diseases. Drug repositioning may be an effective response to public health threats related to the spread of multidrug-resistant bacterial strains and the growing antibiotic resistance of microorganisms.

Hypidone hydrochloride (YL-0919) protects mice from meningitis via Sigma1R-STAT1-NLRP3-GSDMD pathway

BACKGROUND

A growing number of studies have found that antidepressants have anti-inflammatory effects while protecting nerves. Hypidone hydrochloride (YL-0919) is a novel highly selective 5-HT reuptake blocker. Our previous studies have demonstrated that YL-0919 exerts notable antidepressant- and anxiolytic-like as well as procognitive effects. However, whether YL-0919 can be used to treat inflammatory and infectious diseases remain unknown. In this study, we aimed to verify the anti-inflammatory effect of YL-0919 on bacterial meningitis and further explore the potential molecular mechanisms.

METHODS

We performed the experiments on pneumococcal meningitis mice in vivo and S. pneumoniae infected macrophages/microglia in vitro, with or without YL-0919 treatment. Cognitive function was evaluated by open-field task, Morris water maze test, and novel object recognition test. Histopathological staining and immunofluorescence staining were used to detect the pathological damage of meningitis and NLRP3 inflammasome activation in microglia/macrophages. The expression of the STAT1/NLRP3/GSDMD signal pathway was measured by western blots. Proinflammatory cytokines associated with pyroptosis were detected by ELISA.

RESULTS

YL-0919 protected mice from fatal pneumococcal meningitis, characterized by attenuated cytokine storms, decreased bacterial loads, improved neuroethology, and reduced mortality. NLRP3 plays a key role in the regulation of inflammation. When the underlying mechanisms were investigated, we found that YL-0919 inhibited the activation of NLRP3 via STAT1, and thus inhibited macrophages/microglia pyroptosis, resulting in downregulation of proinflammatory cytokines. In addition, Sigma1R was identified as a pivotal receptor that can be engaged by YL-0919 to inhibit NLRP3 activation and pyroptosis pathway in microglia/macrophages.

CONCLUSIONS

These results provide new insights into the mechanisms of inflammation regulation mediated by the antidepressant YL-0919. Moreover, targeting the STAT1/NLRP3 pyroptosis pathway is a promising strategy for the treatment of infectious diseases like bacterial meningitis.

AADB: A Manually Collected Database for Combinations of Antibiotics With Adjuvants

Antimicrobial resistance is a global public health concern. The lack of innovations in antibiotic development has led to renewed interest in antibiotic adjuvants. However, there is no database to collect antibiotic adjuvants. Herein, we build a comprehensive database named Antibiotic Adjuvant DataBase (AADB) by manually collecting relevant literature. Specifically, AADB includes 3,035 combinations of antibiotics with adjuvants, covering 83 antibiotics, 226 adjuvants, and 325 bacterial strains. AADB provides user-friendly interfaces for searching and downloading. Users can easily obtain these datasets for further analysis. In addition, we also collected related datasets (e.g., chemogenomic and metabolomic data) and proposed a computational strategy to dissect these datasets. As a test case, we identified 10 candidates for minocycline, and 6 of 10 candidates are the known adjuvants that synergize with minocycline to inhibit the growth of E. coli BW25113. We hope that AADB can help users to identify effective antibiotic adjuvants. AADB is freely available at http://www.acdb.plus/AADB.

Antibacterial activity of paroxetine against Staphylococcus aureus and possible mechanisms of action

Aim: To evaluate the antibacterial activity of paroxetine alone and associated with oxacillin against isolates of methicillin-sensitive and -resistant Staphylococcus aureus. Materials & methods: The broth microdilution and checkerboard techniques were used, with investigation of possible mechanisms of action through flow cytometry, fluorescence microscopy and molecular docking, in addition to scanning electron microscopy for morphological analysis. Results: Paroxetine showed a MIC of 64 μg/ml and bactericidal activity, mostly additive interactions in combination with oxacillin, evidence of action on genetic material and membrane, morphological changes in microbial cells and influence on virulence factors. Conclusion: Paroxetine has antibacterial potential from the perspective of drug repositioning.

Role of the Intestinal Microbiota in the Genesis of Major Depression and the Response to Antidepressant Drug Therapy: A Narrative Review

A major depressive disorder is a serious mental illness characterized by a pervasive low mood that negatively concerns personal life, work life, or education, affecting millions of people worldwide. To date, due to the complexity of the disease, the most common and effective treatments consist of a multi-therapy approach, including psychological, social, and pharmacological support with antidepressant drugs. In general, antidepressants are effective in correcting chemical imbalances of neurotransmitters in the brain, but recent evidence has underlined the pivotal role of gut microbiota (GM) also in the regulation of their pharmacokinetics/pharmacodynamics, through indirect or direct mechanisms. The study of these complex interactions between GM and drugs is currently under the spotlight, and it has been recently named "pharmacomicrobiomics". Hence, the purpose of this review is to summarize the contribution of GM and its metabolites in depression, as well as their role in the metabolism and activity of antidepressant drugs, in order to pave the way for the personalized administration of antidepressant therapies.

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

Microbial diversity is reduced in the gut microbiota of animals and humans treated with selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs). The mechanisms driving the changes in microbial composition, while largely unknown, is critical to understand considering that the gut microbiota plays important roles in drug metabolism and brain function. Using Escherichia coli, we show that the SSRI fluoxetine and the TCA amitriptyline exert strong selection pressure for enhanced efflux activity of the AcrAB-TolC pump, a member of the resistance-nodulation-cell division (RND) superfamily of transporters. Sequencing spontaneous fluoxetine- and amitriptyline-resistant mutants revealed mutations in marR and lon, negative regulators of AcrAB-TolC expression. In line with the broad specificity of AcrAB-TolC pumps these mutants conferred resistance to several classes of antibiotics. We show that the converse also occurs, as spontaneous chloramphenicol-resistant mutants displayed cross-resistance to SSRIs and TCAs. Chemical-genomic screens identified deletions in marR and lon, confirming the results observed for the spontaneous resistant mutants. In addition, deletions in 35 genes with no known role in drug resistance were identified that conferred cross-resistance to antibiotics and several displayed enhanced efflux activities. These results indicate that combinations of specific antidepressants and antibiotics may have important effects when both are used simultaneously or successively as they can impose selection for common mechanisms of resistance. Our work suggests that selection for enhanced efflux activities is an important factor to consider in understanding the microbial diversity changes associated with antidepressant treatments. IMPORTANCE Antidepressants are prescribed broadly for psychiatric conditions to alter neuronal levels of synaptic neurotransmitters such as serotonin and norepinephrine. Two categories of antidepressants are selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs); both are among the most prescribed drugs in the United States. While it is well-established that antidepressants inhibit reuptake of neurotransmitters there is evidence that they also impact microbial diversity in the gastrointestinal tract. However, the mechanisms and therefore biological and clinical effects remain obscure. We demonstrate antidepressants may influence microbial diversity through strong selection for mutant bacteria with increased AcrAB-TolC activity, an efflux pump that removes antibiotics from cells. Furthermore, we identify a new group of genes that contribute to cross-resistance between antidepressants and antibiotics, several act by regulating efflux activity, underscoring overlapping mechanisms. Overall, this work provides new insights into bacterial responses to antidepressants important for understanding antidepressant treatment effects.

Anti-infective properties of proton pump inhibitors: perspectives

Infectious diseases are among the main causes of morbidity and mortality today. In facing this crisis, the development of new drug options and combat strategies is necessary. In this sense, drug repositioning or drug redirection has emerged for the faster identification of effective drugs. In this “Commentary,” the anti-infective properties of the class of proton pump inhibitors (PPIs) are emphasized. Studies report activities against bacterial, fungal, parasitic, and viral agents. In addition, we have provided in a table a summary of the specific characteristics of PPIs and some of their anti-infective activities.