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Biofunctionalization of nylon nanofibers to be used in immunobiosensor for biological warfare agents detecting
(Formatex Research Center, 2018) Peraile, Inés; Lorenzo Lozano, P.; Murillo, N.; Maudes, J.; Rozas Sanz, Gabriel; Pérez Márquez, Ana; González López, L.; Cabria Ramos, Juan Carlos; Gil García, M.
The use of biological warfare agents involves a growing threat to society. Thus, the most countries have been forced to increase resources in research for their detection and identification. One of the critical points in the effective fight against these agents is the development of devices that allow their detection and early identification. The best choice is the immunobiosensors easy to use on-site. However, how the antibody is attached to the biosensor surface, in terms of density and orientation, will determine the diagnosis capability of the device. In this study, both a functional nanofiber able to increase the surface / volume relation, and a chemicallysimilar planar membrane were used as support for the immobilization of antibodies. Different antibody immobilization systems were carried out to biofunctionalize both surfaces: passive adsorption, covalent bond by glutaraldehyde and well-oriented immobilization by protein A/G. Our results showed that nanofibers in combination with protein A/G were a very effective immunocapture system for being used in a biosensor.
lnactivation and identification of Bacillus anthracis spores
(Wageningen Academic Publishers, 2013-12) Gil García, M.; Peraile, Inés; Jiménez Pérez, M. V.; Cabria Ramos, Juan Carlos; Lorenzo Lozano, P.
Bacillus anthracis endospores must be handled ata biosafety level-3 (BSL-3} eontainment facility, therefore an appropriate inaetivation procedure is essential in order to both detect thcm in a reliable and rapid way and to avoid human infections from antrax-contamined samples if a biosafety level-3 laboratory is not availablc. Unfortunatcly, donnant spores exhibit incredible hardiness against gennicidal agents. The most effective methods for inactivating spores are usually the chemical treatment, heat inactivation (boiling, moist hcat, dry heat) and irTadiation (microwave, UV, gamma, electron beam). The inactivation method used must alter thc cell structure as little as possible in order to ensure a corree! diagnosis by diferent techniques. Several kinds ofphysical and chemical inactivation methods wcrc assessed in order to define the conditions that ensure inactivation of endospores of B. anthracis 34F2 Sterné and pcrmit, at the same time, its identification by PCR and immunoassays techniques.
Reuse of nanofibers in a Biological Warfare Agent detection nanophotonic sensing device
(CBRNE Research and Inovation, 2019-05-29) Peraile, Inés; Lorenzo Lozano, P.; González López, L.; Murillo, Nieves; Dabbagh Escalante, Nushin Alba; Rozas Sanz, Gabriel; Cabria Ramos, Juan Carlos; Gil García, M.
"The use of biological injurious agent ravages not only at human population but also at livestock and crops [1], causing effects both on human health and on the economy [2]. Therefore, the fast and specific detection of these biological injurious agents is necessary in many fields such as environmental control, clinic diagnostic, food industry, Security and Defence. Therefore, much effort has been devoted to the development of new technologies for their detection and identification. The priority objective is to carry out a low cost, easy-of-use and specific device to be used on site and able to be miniaturized [3]. In order to meet this need, the specificity of the antigen-antibody binding is applied in a multitude of biosensors. Among these immuno-biosensors, biological warfare agent detection equipment stands out. Provided both the high costs for this equipment and the need for the first responders to move into the CBRN accident area, it could be desirable to have reusable detection devices.
In the OPTONANOSENS project, an immuno-biosensor with nanophotonic sensing has been developing. In this device, nylon nanofibers with 5% pyridine, manufactured by Tecnalia laid on a metallic support is used to immobilized antibodies [4,5]. The aims of this work are both to make a comparison between several procedures which let these nanofibers to be reused in different detection events and the optimisation of the more suitable procedure which allows a repetitive use and reliable of the biofunctionalized nanofibers in the final sensing device."
Rapid identification of Bacillus anthracis by real-time PCR with dual hybridization probes in environmental swabs
(Elsevier, 2017-11-04) Bassy Alvarez, Olga; Jiménez, Oscar; Ortega García, María Victoria; Granja, Carmen; Cabria Ramos, Juan Carlos
In the present study, we report the development of a real-time PCR assay for the identification of Bacillus anthracis, based on the amplification of a unique chromosomal marker, the E4 sequence, with dual hybridization probes. The assay was evaluated using a panel of ten B. anthracis strains, two B. anthracis isolates from human clinical samples, 12 B. anthracis environmental swabs and 40 non- B. anthracis strains. All 12 B. anthracis strains and clinical isolates were correctly detected, and the method did not show cross-reactions with other micro-organisms. Likewise, the E4 sequence was not found in those strains of B. thuringiensis and B. cereus closely related (homology > 90%) to B. anthracis by computer analysis. On the other hand, this molecular assay showed a high analytical sensitivity, 3.5 genome equivalents per reaction at 95% probability. Furthermore, the real-time PCR assay allowed sequence-specific detection of the amplicon (melting peak with a Tm of 63.5 °C ± 0.5 °C) without post-amplification procedures, which offers an additional advantage over other qPCR assays for B. anthracis detection. Finally, the performance of the method was successfully evaluated in 12 environmental samples. In summary, we have developed a rapid and specific method for the molecular identification of Bacillus anthracis in environmental samples.
Recovery of Francisella tularensis from soil samples by filtration and detection by real-time PCR and cELISA
(Royal Society of Chemistry, 2008-01-17) Sellek Cano, Ricela; Jiménez, Oscar; Aizpurua, Carmen; Fernández Frutos, Begoña; De León, Patricia; Camacho, Maite; Fernández Moreira, Daniel; Ybarra, Carmen; Cabria Ramos, Juan Carlos
The aim of this study was to develop a specific and highly sensitive method able to detect very low concentrations of Francisella tularensis in soil samples by real-time PCR (qPCR) with SYBR Green I. tul4gene, which encodes the 17-kDa protein (TUL4) in F. tularensis strains, was amplified using a LightCycler (LC) device. We achieved a detection limit of 0.69 fg of genomic DNA from F. tularensis subp. holarctica live vaccine strain (LVS), corresponding to a value less than 3.4 genome equivalents per reaction. The qPCR was shown to be specific, highly sensitive and reproducible. In addition, we evaluated 2 new methods for recovering bacteria from soil based on 1-step filtration using glass fiber filters and PVDF filters. These filtration methods enabled us to recover F. tularensis efficiently from soil samples. As few as 50 CFU per 0.5 g of soil were detected by qPCR. Capture enzyme-linked immunosorbent assay (cELISA) allowed us to detect and quantify the amount of bacteria recovered from soil by an immunological method. Although qPCR was more sensitive than cELISA, we did not observe substantial differences in the amount of bacteria quantified by both methods.
Preliminary validation of real-time PCR assays for the identification of Yersinia pestis
(De Gruyter Brill, 2008-07-21) Tomaso, Herbert; Jacob, Daniela; Eickhoff, Meike; Scholz, Holger; Al Dahouk, Sascha; Kattar, Mireille; Reischl, Udo; Plicka, Helga; Strand Olsen, Jaran; Nikkari, Simo; Matero, Pirjo; Beuret, Christian; Ciammaruconi, Andrea; Lista, Florigio; Gala, Jean Luc; Broll, Hermann; Appel, Bernd; Sellek Cano, Ricela; Ybarra, María del Carmen; Broekhuijsen, Martien; Indra, Alexander; Petersen, Roger; Neubauer, Heinrich
Background: Yersinia pestis (Y. pestis) is a zoonotic bacterium mainly circulating among rodents and their fleas. Transmission to humans can cause bubonic, pneumonic or septicemic plague with a high case-fatality rate. Therefore, rapid and reliable diagnostic tools are crucial. The objective of this study was to assess the inter-laboratory reproducibility of in-house developed real-time PCR assays for the identification of Y. pestis.
Methods: A total of four samples of quantified Y. pestis DNA and two blank samples were sent blinded to 14 laboratories. To standardize the procedures, oligonucleotides were provided and the same instrument platform and a commercial mastermix were used. The participants were requested to report their results including cycle threshold and melting temperature values.
Results: All participating laboratories were able to perform the real-time PCR assays according to the protocols provided and identified the samples containing Y. pestis DNA correctly. Significant differences between the reference laboratory and participating laboratories were observed in cycle threshold values and melting temperatures. This, however, did not adversely affect the interpretation of results.
Conclusions: Our real-time PCR system proved to be highly reproducible and has the potential of complementing the diagnostic tools for rapid identification of Y. pestis isolates. Further steps of validation are needed to determine diagnostic accuracy and predictive values with clinical samples.
