Pseudomonas aeruginosa is an opportunistic pathogen that causes acute and chronic infections in humans. Pyocins are bacteriocins produced by P. aeruginosa that are usually released through lysis of the producer strains. Expression of pyocin genes is negatively regulated by PrtR, which gets cleaved under SOS response, leading to upregulation of pyocin synthetic genes. Previously, we demonstrated that PrtR is required for the expression of type III secretion system (T3SS), which is an important virulence component of P. aeruginosa. In this study, we demonstrate that mutation in prtR results in reduced bacterial colonization in a mouse acute pneumonia model. Examination of bacterial and host cells in the bronchoalveolar lavage fluids from infected mice revealed that expression of PrtR is induced by reactive oxygen species (ROS) released by neutrophils. We further demonstrate that treatment with hydrogen peroxide or ciprofloxacin, known to induce the SOS response and pyocin production, resulted in an elevated PrtR mRNA level. Overexpression of PrtR by a tac promoter repressed the endogenous prtR promoter activity, and electrophoretic mobility shift assay revealed that PrtR binds to its own promoter, suggesting an autorepressive mechanism of regulation. A high level of PrtR expressed from a plasmid resulted in increased T3SS gene expression during infection and higher resistance against ciprofloxacin. Overall, our results suggest that the autorepression of PrtR contributes to the maintenance of a relatively stable level of PrtR, which is permissive to T3SS gene expression in the presence of ROS while increasing bacterial tolerance to stresses, such as ciprofloxacin, by limiting pyocin production.
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http://dx.doi.org/10.1128/IAI.01388-13 | DOI Listing |
Sensors (Basel)
December 2024
Electronics Departament, University of Alcalá (UAH), 28805 Alcalá de Henares, Madrid, Spain.
The use of Deep Learning algorithms in the domain of Decision Making for Autonomous Vehicles has garnered significant attention in the literature in recent years, showcasing considerable potential. Nevertheless, most of the solutions proposed by the scientific community encounter difficulties in real-world applications. This paper aims to provide a realistic implementation of a hybrid Decision Making module in an Autonomous Driving stack, integrating the learning capabilities from the experience of Deep Reinforcement Learning algorithms and the reliability of classical methodologies.
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December 2024
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Foods
December 2024
Department of Food Technology, Nutrition and Food Science, Veterinary Faculty, University of Murcia, Regional Campus of International Excellence "Campus Mare Nostrum", 30100 Murcia, Spain.
Dietary fiber (DF), and especially soluble dietary fiber (SDF), is a nutrient of particular interest today because of its anti-inflammatory role and its ability to reduce cardiovascular risk. Therefore, the enhancement of SDF in foods using different techniques has become a promising field of research. In order to prove the possibility of increasing this SDF content, the effects of different commercial enzymes (Pectinex Ultra SP-L, Viscozyme L and Celluclast 1.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
NanoMag Lab, Department of Applied Physics, Faculty of Science University of Granada, Planta-1, Edificio I+D Josefina Castro, Av. de Madrid, 28, 18012 Granada, Spain.
Local hyperthermia is gaining considerable interest due to its promising antitumor effects. In this context, dual magneto-photothermal cancer therapy holds great promise. For this purpose, the use of nanomaterials has been proposed.
View Article and Find Full Text PDFEnviron Monit Assess
January 2025
EKOPOL, Research Group On Ecological Economics and Political Ecology, Faculty of Social Sciences and Communication, University of the Basque Country (UPV/EHU), Sarriena S/N, 48940, Leioa, Basque Country, Spain.
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