Objectives: Chronic infections and treatment failure are concerning issues in patients with Pseudomonas aeruginosa infections. Persister cell formation in biofilm is considered a key reason for antibiotic resistance and treatment failure. In this study, expression of type II toxin/antitoxin (TA) system genes (relBE, Xre-COG5654, vapBC and Xre-GNAT) in persister cells of biofilm was evaluated in the presence of the antibiotics ciprofloxacin and colistin during exponential and stationary phases.
Methods: The impact of antibiotics on biofilm persister cell formation during exponential and stationary phases of P. aeruginosa strains was examined by colony count at different time intervals in the presence of 5-fold minimum inhibitory concentration (MIC) of ciprofloxacin and colistin. Furthermore, expression of relBE, Xre-COG5654, vapBC and Xre-GNAT genes in P. aeruginosa strains undergoing antibiotic treatment for 3.5 h during exponential and stationary phases was examined by RT-qPCR.
Results: Formation of persister cells was observed in biofilms formed by P. aeruginosa strains in the presence of 5 × MIC of ciprofloxacin and colistin compared with the control group after 3.5 h of incubation both during exponential and stationary phases. The number of biofilm persister cells was higher in stationary phase than in exponential phase. According to the findings of RT-qPCR, ciprofloxacin and colistin may induce persister cell formation by enhancing the expression of type II TA systems during stationary and exponential phases.
Conclusion: The result of this study indicate that ciprofloxacin and colistin have the potential to increase persister cells formation in biofilms by influencing the expression of type II TA systems.
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http://dx.doi.org/10.1016/j.jgar.2021.11.009 | DOI Listing |
Gastroenterol Clin North Am
March 2025
Department of Gastroenterology, All India Institute of Medical Sciences, New Delhi 110029, India. Electronic address:
Organ failure (OF) is a sinister development in the clinical course of acute pancreatitis, and its prediction is crucial for triaging the patient. Persistent systemic inflammatory response syndrome and raised interleukin-6 levels have a good predictive accuracy. Pathophysiology involves the release of damage-associated molecular patterns as a consequence of pancreatic injury, recruitment of inflammatory cells, and the release of proinflammatory cytokines and chemokines causing cytokine storm.
View Article and Find Full Text PDFToxicol In Vitro
January 2025
School of Public Health, Nantong University, Nantong 226019, Jiangsu, China. Electronic address:
2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) belongs to the category of persistent environmental pollutants, and gestational exposure to TCDD can lead to cognitive, memory, and motor deficits, as well as altered neuron development in rodents. However, the molecular mechanisms underlying TCDD's neurotoxicity remine unclear. Neural stem cells (NSCs) possess the capacity for self-renewal and can generate various cell types within the brain, playing fundamental roles in brain development and regeneration.
View Article and Find Full Text PDFCell Metab
January 2025
Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA; Tumor Microenvironment Center, UPMC Hillman Cancer Center, Pittsburgh, PA, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. Electronic address:
Cellular therapies are living drugs whose efficacy depends on persistence and survival. Expansion of therapeutic T cells employs hypermetabolic culture conditions to promote T cell expansion. We show that typical in vitro expansion conditions generate metabolically and functionally impaired T cells more reliant on aerobic glycolysis than those expanding in vivo.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Department of Molecular Microbiology, Washington University in St. Louis, School of Medicine, St. Louis, MO 63130.
bradyzoites reside in tissue cysts that undergo cycles of expansion, rupture, and release to foster chronic infection. The glycosylated cyst wall acts as a protective barrier, although the processes responsible for formation, remodeling, and turnover are not understood. Herein, we identify a noncanonical chitinase-like enzyme TgCLP1 that localizes to micronemes and is targeted to the cyst wall after secretion.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
Kavli Institute for Systems Neuroscience and Centre for Algorithms in the Cortex, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.
Persistent homology applied to the activity of grid cells in the Medial Entorhinal Cortex suggests that this activity lies on a toroidal manifold. By analyzing real data and a simple model, we show that neural oscillations play a key role in the appearance of this toroidal topology. To quantitatively monitor how changes in spike trains influence the topology of the data, we first define a robust measure for the degree of toroidality of a dataset.
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