Suchergebnisse

[EN] The development of new detection systems for an accurate and rapid identification of pathogens has become an essential challenge in the biomedical field. Herein a highly selective platform based on aptamer-gated nano materials for specific Staphylococcus aureus detection is presented. In the proposed design, a nanoporous anodic alumina (NAA) scaffold is loaded with the fluorescent indicator rhodamine B, while pores entrances are capped by a DNA aptamer which selectively recognizes S. aureus cells in less than 1 h. When S. aureus cells are present, the solid is selectively uncapped, and the dye is released to the medium. This nanodevice allows the detection of bacterial concentrations between 2 and 5 CFU mL-1 (in buffer and blood, respectively) and it has demonstrated excellent behavior in terms of specificity and robustness. A set of 25 different clinical samples are analyzed using this simple procedure obtaining excellent results, which agree with conventional hospital reference techniques for the identification of S. aureus. This new method is sensitive, rapid and low cost, and avoids steps such as polymerase chain amplification reaction, which makes it suitable for use in point-of-care detection systems. ; This study was supported by the Spanish Government (projects RTI2018-100910-B-C41 and SAF2017-82251-R (MCUI/AEI/FEDER, UE)), the Generalitat Valenciana (project PROMETEO/2018/024), the Universitat Politecnica de Valencia-Instituto de Investigacion Sanitaria La Fe (B02-MIRSA project) and CIBER-BBN (NANOPATH and valorization project CANDI-EYE). It has been also co-financed by the EU through the Valencian Community ERDF PO 2014-2020. S.S. thanks the Instituto de Salud Carlos III and the European Social Fund for the financial support "Sara Borrell" (CD16/000237). L.P. thanks to Ministerio de Economia, Industria y Competitividad for his FPI grant. The authors are grateful for the professional English language editing to Mr. Arash Javadinejad, English Instructor and pubication Editor at the Instituto de ...

[EN] In recent times, many approaches have been developed against drug resistant Gram-negative bacteria. However, low-cost high effective materials which could broaden the spectrum of antibiotics are still needed. In this study, enhancement of linezolid spectrum, normally active against Gram-positive bacteria, was aimed for Gram-negative bacteria growth inhibition. For this purpose, a silica xerogel prepared from a low-cost precursor is used as a drug carrier owing to the advantages of its mesoporous structure, suitable pore and particle size and ultralow density. The silica xerogel is loaded with linezolid and capped with epsilon-poly-l-lysine. The developed nano-formulation shows a marked antibacterial activity against to Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. In comparison to free linezolid and epsilon-poly-l-lysine, the material demonstrates a synergistic effect on killing for the three tested bacteria. The results show that silica xerogels can be used as a potential drug carrier and activity enhancer. This strategy could provide the improvement of antibacterial activity spectrum of antibacterial agents like linezolid and could represent a powerful alternative to overcome antibiotic resistance in a near future. ; We thank the Spanish Government (projects RTI2018-100910-B-C41, RTI2018-101599-B-C22-AR and SAF2017-82251-R (MCUI/AEI/FEDER, UE)) and the Generalitat Valenciana (project PROMETEO/2018/024) for support. G.G.K. would like to thank Academic Staff Training Program (2016-OYP-071) and TUBITAK for 2214-A International Research Fellowship Program for PhD Students. S.M. thanks Generalitat Valenciana for her Santiago Grisolia fellowship. V.C.-N. thanks Spanish Ministerio de Educacion for his FPU grant (FPU15/02753). ; Guzel Kaya, G.; Medaglia, S.; Candela-Noguera, V.; Tormo-Mas, MÁ.; Marcos Martínez, MD.; Aznar, E.; Deveci, H. (2020). Antibacterial Activity of Linezolid against Gram-Negative Bacteria: Utilization of E-Poly-l-Lysine Capped Silica Xerogel as an Activating Carrier. ...