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] Pneumocystis pneumonia (PcP) is a disease produced by the opportunistic infection of the fungus Pneumocystis jirovecii. As delayed or unsuitable treatments increase the risk of mortality, the development of rapid and accurate diagnostic tools for PcP are of great importance. Unfortunately, current standard methods present severe limitations and are far from adequate. In this work, a time-competitive, sensitive and selective biosensor based on DNA-gated nanomaterials for the identification of P. jirovecii is presented. The biosensor consists of a nanoporous anodic alumina (NAA) scaffold which pores are filled with a dye reporter and capped with specific DNA oligonucleotides. In the presence of P. jirovecii genomic DNA, the gated biosensor is open, and the cargo is delivered to the solution where it is monitored through fluorescence spectroscopy. The use of capping oligonucleotides able to form duplex or triplex with P. jirovecii DNA is studied. The final diagnostic tool shows a limit of detection (LOD) of 1 nM of target complementary DNA and does not require previous amplification steps. The method was applied to identify DNA from P. jirovecii in unmodified bronchoalveolar lavage, nasopharyngeal aspirates, and sputum samples in 60 min. This is a promising alternative method for the routinely diagnosis of Pneumocystis pneumonia. ; This research was funded by the Spanish Government, (projects RTI2018-100910-B-C41 (MCUI/AEI/FEDER, UE) and CTQ2017-84415-R), the Generalitat Valenciana (project PROMETEO/2018/024) and CIBER-BBN (projects NANOPATH and CANDI-EYE). ; Pla, L.; Aviñó, A.; Eritja, R.; Ruiz-Gaitán, A.; Pemán, J.; Friaza, V.; Calderón, EJ. (2020). Triplex hybridization-based nanosystem for the rapid screening of pneumocystis pneumonia in clinical samples. Journal of Fungi. 6(4):1-14. https://doi.org/10.3390/jof6040292 ; S ; 1 ; 14 ; 6 ; 4 ; Fauchier, T., Hasseine, L., Gari-Toussaint, M., Casanova, V., Marty, P. M., & Pomares, C. (2016). Detection of Pneumocystis jirovecii by Quantitative PCR To ...