Efflux pumps are considered a major potential contributor to the development of various forms of resistance in Mycobacterium tuberculosis leading to the emergence of multidrug-resistant tuberculosis (TB). Verapamil (VER) and tricyclic chemosensitizers such as the phenothiazines are known to possess efflux pump inhibition properties and have demonstrated significant efficacy in various TB disease models. Novel hybrid molecules based on fusion of the VER substructure with various tricyclic, as well as nontricyclic, chemosensitizer cores or their structural motifs are described. These hybrid compounds were evaluated in vitro and ex vivo individually for their intrinsic activity and in combination for their potentiating potential with the frontline anti-TB drugs, rifampin and isoniazid. In addition, efflux pump inhibition was assessed in an ethidium bromide assay. This study led to the identification of novel compounds, termed hybrid efflux pump inhibitors, with intrinsic antimycobacterial activities (MIC ≤ 3.17 μg/mL) and intracellular activity in macrophages at a low concentration (≤6.25 μg/mL).
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http://dx.doi.org/10.1021/acsinfecdis.6b00111 | DOI Listing |
Arch Microbiol
January 2025
Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan, UMS, 88400, Kota Kinabalu, Sabah, Malaysia.
The agricultural productivity and world-wide food security is affected by different phytopathogens, in which Fusarium is more destructive affecting more than 150 crops, now got resistance against many fungicides that possess harmful effects on environment such as soil health, air pollution, and human health. Fusarium fungicide resistance is an increasing concern in agricultural and environmental contexts, requiring a thorough understanding of its causes, implications, and management approaches. The mechanisms of fungicide resistance in Fusarium spp.
View Article and Find Full Text PDFVet Med Sci
January 2025
Department of Veterinary Hygiene and Management, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
A major risk to the poultry industry is antimicrobial resistance (AMR), specifically with regard to Mycoplasma gallisepticum (MG) infections. The sensitivity patterns of 100 MG isolates to biocides and antibiotics were examined in this study to clarify the interactions between antimicrobial agents and resistance mechanisms. The antimicrobial activity against MG was assessed using broth microdilution, and the results are shown as the minimum inhibitory concentration (MIC) for each strain, the MIC distribution (range), the MIC, and/or the MIC.
View Article and Find Full Text PDFFEMS Microbiol Lett
January 2025
Rochester Institute of Technology, Thomas H. Gosnell School of Life Sciences, Rochester, NY, USA.
Commensal Neisseria are members of a healthy human oropharyngeal microbiome; however, they also serve as a reservoir of antimicrobial resistance for their pathogenic relatives. Despite their known importance as sources of novel genetic variation for pathogens, we still do not understand the full suite of resistance mutations commensal species can harbor. Here, we use in vitro selection to assess the mutations that emerge in response to ciprofloxacin selection in commensal Neisseria by passaging 4 replicates of 4 different species in the presence of a selective antibiotic gradient for 20 days; then categorized derived mutations with whole genome sequencing.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Normal University, Xi'an 710119, P. R. China.
High expression of drug efflux pump makes antibiotics ineffective against bacteria, leading to drug-resistant strains and even the emergence of "superbugs". Herein, we design and synthesize a dual functional o-nitrobenzene (NB)-modified conjugated oligo-polyfluorene vinylene (OPFV) photosensitizer, OPFV-NB, which can depress efflux pump activity and also possesses photodynamic therapy (PDT) for synergistically overcoming drug-resistant bacteria. Upon light irradiation, the OPFV-NB can produce aldehyde active groups to covalently bind outer membrane proteins, such as tolerant colicin (TolC), blocking drug efflux of bacteria.
View Article and Find Full Text PDFToxicol Sci
January 2025
Takeda Development Center Americas, Inc, Cambridge, MA, USA.
The frequency of drug-induced liver injury (DILI) in clinical trials remains a challenge for drug developers despite advances in human hepatotoxicity models and improvements in reducing liver-related attrition in preclinical species. TAK-994, an oral orexin receptor 2 agonist, was withdrawn from phase II clinical trials due to the appearance of severe DILI. Here, we investigate the likely mechanism of TAK-994 DILI in hepatic cell culture systems examined cytotoxicity, mitochondrial toxicity, impact on drug transporter proteins, and covalent binding.
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