16 research outputs found

    Rol de la microbiota en pacientes con bronquiectasias no asociadas a la fibrosis quística

    Get PDF
    [spa] El pulmón siempre se ha considerado estéril. Sin embargo, el campo de la microbiota pulmonar se ha visto revolucionado por el avance de las técnicas moleculares. Cada individuo tiene un perfil de microbiota único, definido como el conjunto de microorganismos presentes en un ambiente establecido, que ha coevolucionado con el huésped y coloniza sus tejidos mucosos, formando una relación mutualista y simbiótica. El término microbioma se utiliza para describir todo el hábitat, que incluye los microorganismos, sus genomas y las condiciones ambientales circundantes. La microbiota pulmonar es escasa, crece en un ambiente pobre en nutrientes y está en constante renovación, debido a la función pulmonar (tos, aclaramiento mucociliar, mecanismo de defensa del huésped) y la migración desde el tracto respiratorio superior y la dispersión de la mucosa. Además, la edad, la genética y el entorno contribuyen a la variabilidad individual y la constante evolución a lo largo de la vida. Los principales filos en pulmones sanos son Proteobacteria, Firmicutes y Bacteroidetes, mientras que a nivel de género predominan Streptococcus, Prevotella y Veillonella, esta última con menor contribución en el desarrollo, progresión y agudizaciones de las enfermedades pulmonares. De hecho, la estructura alterada del pulmón, el curso de la enfermedad y los tratamientos crónicos pueden desencadenar cambios en la microbiota pulmonar, lo que lleva a desequilibrios en la comunidad microbiana, también conocida como disbiosis. En este trabajo se ha estudiado en primer lugar cual era la combinación de regiones hypervariables del gen 16S rRNA ribosomal (V1V2, V3V4, V5V7, V7V9) con mayor sensibilidad y especificidad respecto a la identificación taxonómica en muestras de esputo. Se utilizó un control estándar de microbiota comercial para validar los resultados. Nuestro estudio confirma que cada región hipervariable 16S rRNA proporciona diferencias significativas en la identificación taxonómica en el esputo. En particular, nuestros resultados sugieren que V1V2 en lugar de V3V4 exhibe un mayor poder de resolución para la identificación de taxonomía. Por lo tanto, las plataformas de secuenciación de tercera generación de 16S rRNA de longitud completa están más disponibles y mejoran las tasas de error, V1V2 se puede usar para la identificación taxonómica en el esputo. El hallazgo puede permitir en futuros trabajos de microbiota respiratoria utilizar las regiones adecuadas para evitar sesgos en la información taxonómica resultante de estos. Una vez obtenida esta aproximación metodológica se ha demostrado que la alta carga bacteriana de P. aeruginosa se asocia con la aparición de un patobioma. Los resultados demuestran una asociación significativa entre la presencia de una alta carga de P. aeruginosa y la disminución de la diversidad, abundancia y variabilidad de la flora concomitante, posicionando la agrupación de la carga de P. aeruginosa como un biomarcador microbiano potencial en pacientes con bronquiectasias. Estos hallazgos brindan la base para extrapolar el estado del microbioma según la carga de P. aeruginosa mediante cultivos estándares en la rutina de la microbiología clínica y comprender mejor la gravedad del paciente no tan solo según el patógeno sino según la disbiosis que comporta el patógeno per se. Una vez encontrado este patobioma según la carga bacteriana de P. aeruginosa en la etapa final de este estudio se hipotetizó si clusterizando por fenotipo de P. aeruginosa (mucoide y no mucoide) encontraríamos el establecimiento de un patobioma. El fenotipo mucoide es típico de los biofilms bacterianos y se asocia a la colonización crónica. Los hallazgos fueron exitosos en relación con la hipótesis dado que, según el fenotipo, así como según la carga bacteriana anteriormente demostrada, se encontró un patobioma en pacientes con el fenotipo mucoide. El presente estudio nos ha permitido encontrar la región hipervariable más resolutiva para muestras de esputo, identificar el patobioma y como consecuencia la gravedad del paciente por la disbiosis provocada por este patiobioma según la carga bacteriana y según el fenotipo de P. aeruginosa.[eng] The lung has always been considered sterile. However, the field of lung microbiota has been revolutionized by the advance of molecular techniques. Each individual has a unique microbiota profile, defined as the assemblage of microorganisms present in an established environment, that has coevolved with the host and colonizes its mucosal tissues, forming a mutualistic and symbiotic relationship. The term microbiome is used to describe the entire habitat, that includes the microorganisms, their genomes and the surrounding environmental conditions. The lung microbiota is scarce, it grows in a nutrient poor environment, and it is in constant turnover, due to pulmonary function (cough, mucociliary clearance, host defense mechanism) and migration from the upper respiratory tract and mucose dispersion. Moreover, the age, genetics and environment contribute to the individual variability and the constant evolution through life. The main phyla in healthy lungs are Proteobacteria, Firmicutes and Bacteroidetes, while at the genus level Streptococcus, Prevotella and Veillonella predominate, with lesser contributions from Haemophilus and Neisseria. Besides, evidence is growing about the colonization of virus and fungi in the respiratory tract of both healthy and ill individuals. The airway microbiota plays a crucial role in the development, progression and exacerbation of lung diseases. Indeed, the altered structure of the lung, the disease course and the chronic treatments may trigger changes in regional growth conditions, leading to imbalances in the microbial community, also known as dysbiosis. In this work, we have studied, in the first place, which was the combination of hypervariable regions of the bacterial ribosomal 16S rRNA that allows a greater power of taxonomic identification with respect to the others in sputum samples. Our study confirms that each 16S rRNA hypervariable region provides significant differences in taxonomic identification.. Notably, our results suggest that V1V2 rather than V3V4 exhibits higher resolving power for sputum taxonomy identification. Therefore, meanwhile, full-length 16S rRNA third-generation sequencing platforms become more widely available and improve error rates, V1V2 can be used for taxonomic identification in sputum as it has the most resolving power. high among the other hypervariables regions. The finding may allow future respiratory microbiota studies to use the appropriate regions to avoid bias in the resulting taxonomic information. Once this methodological finding was obtained, it has been shown that the high bacterial load of P. aeruginosa is associated with the appearance of a pathobiome. The results demonstrate a significant association between the presence of a high P. aeruginosa load and decreased diversity, abundance, and variability of the concomitant flora, positioning P. aeruginosa load clustering as a potential microbial biomarker in patients with bronchiectasis. These findings provide the basis to extrapolate the state of the microbiome according to P. aeruginosa load using standard cultures in routine clinical microbiology and to better understand the severity of the patient not only according to the pathogen but also according to the dysbiosis caused by the pathogen per se. Once this pathobiome was found according to the bacterial load of P. aeruginosa in the final stage of this study, it was hypothesized whether, by culturing by P. aeruginosa phenotype (mucoid and non- mucoid), we would find the establishment of a pathobiome. The findings were successful in relation to the hypothesis since according to the phenotype, as well as according to the previously demonstrated bacterial load, a pathobiome was found in patients with the mucoid phenotype. The present study has allowed us to find the most resolving hypervariable region for sputum samples, identify the pathobiome and, consequently, the severity of the patient due to the dysbiosis caused by this patiobiome according to the P. aeruginosa load and according to the P. aeruginosa phenotype

    Improvement in detecting cytomegalovirus drug resistance mutations in solid organ transplant recipients with suspected resistance using next generation sequencing

    Get PDF
    Antiviral resistance; Solid organ transplant; Next-generation sequencingResistencia a los antivirales; Trasplante de órganos sólidos; Secuenciación de próxima generaciónResistència als antivirals; Trasplantament d'òrgans sòlids; Seqüenciació de pròxima generacióOBJETIVES: The aim of this study was to identify CMV drug resistance mutations (DRM) in solid organ transplant (SOT) recipients with suspected resistance comparing next-generation sequencing (NGS) with Sanger sequencing and assessing risk factors and the clinical impact of resistance. METHODS: Using Sanger sequencing as the reference method, we prospectively assessed the ability of NGS to detect CMV DRM in the UL97 and UL54 genes in a nationwide observational study from September 2013 to August 2016. RESULTS: Among 44 patients recruited, 14 DRM were detected by Sanger in 12 patients (27%) and 20 DRM were detected by NGS, in 16 (36%). NGS confirmed all the DRM detected by Sanger. The additional six mutations detected by NGS were present in <20% of the sequenced population, being located in the UL97 gene and conferring high-level resistance to ganciclovir. The presence of DRM by NGS was associated with lung transplantation (p = 0.050), the administration of prophylaxis (p = 0.039), a higher mean time between transplantation and suspicion of resistance (p = 0.038) and longer antiviral treatment duration before suspicion (p = 0.024). However, the latter was the only factor independently associated with the presence of DRM by NGS in the multivariate analysis (OR 2.24, 95% CI 1.03 to 4.87). CONCLUSIONS: NGS showed a higher yield than Sanger sequencing for detecting CMV resistance mutations in SOT recipients. The presence of DRM detected by NGS was independently associated with longer antiviral treatment.The present study was funded by Agency for Health Technology Assessment and Research and Ministerio de Economia y Competitividad, Instituto de Salud Carlos III (PS12/02131 and PI17/02150) and by the Agència de Gestió d'Ajuts Universitaris i de Recerca (AGAUR, FI-DGR 2017, Grant No. 00794), which is supported by the Secretaria d'Universitats i Recerca (Economy and Knowledge Department, Generalitat de Catalunya), and co-funded by the European Social Fund and by Fundacio Marato TV3 project (201824). The study sponsor had no role in the collection, analysis, or interpretation of the data

    Resistance mechanisms and molecular epidemiology of Pseudomonas aeruginosa strains from patients with bronchiectasis

    Get PDF
    Non-cystic fibrosis bronchiectasis (BE) is a chronic structural lung condition that facilitates chronic colonization by different microorganisms and courses with recurrent respiratory infections and frequent exacerbations. One of the main pathogens involved in BE is Pseudomonas aeruginosa.To determine the molecular mechanisms of resistance and the molecular epidemiology of P. aeruginosa strains isolated from patients with BE.A total of 43 strains of P. aeruginosa were isolated from the sputum of BE patients. Susceptibility to the following antimicrobials was analysed: ciprofloxacin, meropenem, imipenem, amikacin, tobramycin, aztreonam, piperacillin/tazobactam, ceftazidime, ceftazidime/avibactam, ceftolozane/tazobactam, cefepime and colistin. The resistance mechanisms present in each strain were assessed by PCR, sequencing and quantitative RT-PCR. Molecular epidemiology was determined by MLST. Phylogenetic analysis was carried out using the eBURST algorithm.High levels of resistance to ciprofloxacin (44.19%) were found. Mutations in the gyrA, gyrB, parC and parE genes were detected in ciprofloxacin-resistant P. aeruginosa strains. The number of mutated QRDR genes was related to increased MIC. Different ?-lactamases were detected: blaOXA50, blaGES-2, blaIMI-2 and blaGIM-1. The aac(3)-Ia, aac(3)-Ic, aac(6?)-Ib and ant(2?)-Ia genes were associated with aminoglycoside-resistant strains. The gene expression analysis showed overproduction of the MexAB-OprM efflux system (46.5%) over the other efflux system. The most frequently detected clones were ST619, ST676, ST532 and ST109.Resistance to first-line antimicrobials recommended in BE guidelines could threaten the treatment of BE and the eradication of P. aeruginosa, contributing to chronic infection.© The Author(s) 2022. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy

    Characteristics and Outcomes in Patients with Ventilator-Associated Pneumonia Who Do or Do Not Develop Acute Respiratory Distress Syndrome. An Observational Study

    Get PDF
    Ventilator-associated pneumonia (VAP) is a well-known complication of patients on invasive mechanical ventilation. The main cause of acute respiratory distress syndrome (ARDS) is pneumonia. ARDS can occur in patients with community-acquired or nosocomial pneumonia. Data regarding ARDS incidence, related pathogens, and specific outcomes in patients with VAP is limited. This is a cohort study in which patients with VAP were evaluated in an 800-bed tertiary teaching hospital between 2004 and 2016. Clinical outcomes, microbiological and epidemiological data were assessed among those who developed ARDS and those who did not. Forty-one (13.6%) out of 301 VAP patients developed ARDS. Patients who developed ARDS were younger and presented with higher prevalence of chronic liver disease. Pseudomonas aeruginosa was the most frequently isolated pathogen, but without any difference between groups. Appropriate empirical antibiotic treatment was prescribed to ARDS patients as frequently as to those without ARDS. Ninety-day mortality did not significantly vary among patients with or without ARDS. Additionally, patients with ARDS did not have significantly higher intensive care unit (ICU) and 28-day mortality, ICU, and hospital length of stay, ventilation-free days, and duration of mechanical ventilation. In summary, ARDS deriving from VAP occurs in 13.6% of patients. Although significant differences in clinical outcomes were not observed between both groups, further studies with a higher number of patients are needed due to the possibility of the study being underpowered

    SARS-CoV-2-induced Acute Respiratory Distress Syndrome: Pulmonary Mechanics and Gas-Exchange Abnormalities

    Full text link
    In January 2020, the first cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were reported in Europe. Multiple outbreaks have since then led to a global pandemic, as well as to massive medical, economic, and social repercussions. SARS-CoV-2 pneumonia can develop into acute respiratory distress syndrome (ARDS) when mechanical ventilation (MV) is needed (3, 4). ARDS produces abnormalities in gas exchange with a variable degree of shunt (5), high dead space ventilation (dead space volume [Vd]/tidal volume [Vt] ratio) (6), diminished pulmonary compliance (7), and alterations to the pulmonary circulation (8). The cornerstone of ARDS management is to provide adequate gas exchange without further lung injury as a result of MV. To date, information regarding the characteristics of SARS-CoV-2-induced ARDS is not completely known. However, this information is crucial to better apply MV and facilitate organ support strategies. We therefore present the characteristics of gas exchange, pulmonary mechanics, and ventilatory management of 50 patients with laboratory-confirmed SARS-CoV-2 infection, who developed ARDS and underwent invasive MV (IMV). Methods: Descriptive analysis included 50 consecutive patients with laboratory-confirmed SARS-CoV-2 infection who developed ARDS (9) and underwent IMV. These patients were admitted to the SARS-CoV-2-dedicated intensive care units (ICUs) at Hospital Clinic of Barcelona, Spain, between March 7 and March 25, 2020. Upon ICU admission, epidemiological characteristics, the severity of SARS-CoV-2 infection with the Acute Physiology and Chronic Health Evaluation II score, prognostic biomarkers of SARS-CoV-2 infection (described in Reference 4), time from hospital to ICU admission, time from ICU admission to intubation, oxygen therapy or noninvasive ventilation (NIV) use, and microbiology were investigated. On the day that criteria for ARDS diagnosis were met (9) and IMV was needed, the following assessments were performed: impairment in oxygenation was analyzed with the partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio, and abnormalities of CO2 metabolism were studied with the ventilatory ratio (VR), a surrogate parameter of Vd/Vt. In addition, adjunctive therapies and MV parameters related with ventilation-induced lung injury (VILI) described elsewhere (11-15) were investigated. Correlations of SARS-CoV-2 prognostic biomarkers (4), pulmonary mechanics, and gas-exchange data were performed. Twenty-eight-day and hospital mortality, ventilator- and ICU-free days at Day 28, hospital and ICU lengths of stay, and need for tracheostomy were also evaluated (16). Finally, a subanalysis assessing differences before and after prone positioning was performed. For additional detail on the method, see the online supplement. Results: By March 25th, 2020, 50 patients with laboratory-confirmed SARS-CoV-2 infection and ARDS had been admitted to our hospital. Table 1 shows the demographic and clinical characteristics of these patients. The median (interquartile range [IQR]) age was 66 (57-74) years. Thirty-six patients (72%) were men. Upon ARDS diagnosis, 44% of patients were initially classified as having moderate ARDS, whereas 24% were classified as having mild ARDS and 32% were classified as having severe ARDS. The outcomes of these patients are shown in Table 1. ICU and hospital lengths of stay were prolonged, and tracheostomy was performed in 30 (60%) patients. Hospital mortality was 34%

    Label-free plasmonic biosensor for rapid, quantitative, and highly sensitive COVID-19 serology: implementation and clinical validation

    Get PDF
    Serological tests are essential for the control and management of COVID-19 pandemic, not only for current and historical diagnostics but especially for surveillance, epidemiological, and acquired immunity studies. Clinical COVID-19 serology is routinely performed by enzymatic or chemiluminescence immunoassays (i.e., ELISA or CLIA), which provide good sensitivities at the expense of relatively long turnaround times and specialized laboratory settings. Rapid serological tests, based on lateral flow assays, have also been developed and widely commercialized, but they suffer from limited reliability due to relatively low sensitivity and specificity. We have developed and validated a direct serological biosensor assay employing proprietary technology based on Surface Plasmon Resonance (SPR). The biosensor offers a rapid -less than 15 min- identification and quantification of SARS-CoV-2 antibodies directly in clinical samples, without the need of any signal amplification. The portable plasmonic biosensor device employs a custom-designed multi-antigen sensor biochip, combining the two main viral antigens (RBD peptide and N protein), for simultaneous detection of human antibodies targeting both antigens. The SPR serology assay reaches detection limits in the low ng mL-1 range employing polyclonal antibodies as standard, which are well below the commonly detected antibody levels in COVID-19 patients. The assay has also been implemented employing the first WHO approved anti-SARS-CoV-2 immunoglobulin standard. We have carried out a clinical validation with COVID-19 positive and negative samples (n=120) that demonstrates the excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor device as an accurate, robust, and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the management of COVID-19 patients and for the evaluation of immunological status during vaccination, treatment or in front of emerging variants.H2020 Research and Innovation Programme of the European Commission Project, No. 101003544 Spanish Research Agency (AEI, grant no. SEV-2017-0706AEI, grant no. SEV-2017-0706) Spanish Ministry of Science and Innovation and the Spanish Research Agency and the European Social Fund (ESF)BES-2017-080527 GENCAT-DGRIS COVID EU H2020 Programme (644956) Plan Nacional de I+D+i 2013-2016 ISCIII- Ministerio de Ciencia e Innovación, Vall d’Hebron University Hospital Biobank PT17/0015/0047 European Virus Archive GLOBAL (EVA-GLOBAL) EU Horizon 2020 (grant agreement No. 871029) Fundació Glòria Soler for COVIDBANK collection Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0003)N

    Supporting information Label-Free Plasmonic Biosensor for Rapid, Quantitative, and Highly Sensitive COVID-19 Serology: Implementation and Clinical Validation

    Get PDF
    15 pages. -- Content: 1. Supplementary text: 1.1.Chemical and biological reagents; 1.2.SPR biosensor device; 1.3.Plasmonic sensor chip preparation; 1.4.Clinical samples collection; 1.5.Stratification of convalescent COVID patients. Samples collection from Clinic Hospital (Barcelona); 1.6. Standard analytical techniques (ELISA, CLIA and LFA); 1.7.Data analysis; 1.8.Diagnostic sensitivity and specificity. -- 2. Figures. -- Tables S1-S3. -- References.Serological tests are essential for the control and management of COVID-19 pandemic (diagnostics and surveillance, and epidemiological and immunity studies). We introduce a direct serological biosensor assay employing proprietary technology based on plasmonics, which offers rapid (<15 min) identification and quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in clinical samples, without signal amplification. The portable plasmonic device employs a custom-designed multiantigen (RBD peptide and N protein) sensor biochip and reaches detection limits in the low ng mL–1 range employing polyclonal antibodies. It has also been implemented employing the WHO-approved anti-SARS-CoV-2 immunoglobulin standard. A clinical validation with COVID-19 positive and negative samples (n = 120) demonstrates its excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor as an accurate and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the disease management and for the evaluation of immunological status during vaccination or treatment.Peer reviewe

    Detection of cytomegalovirus drug resistance mutations in solid organ transplant recipients with suspected resistance

    Get PDF
    BACKGROUND: Current guidelines recommend that treatment of resistant cytomegalovirus (CMV) in solid organ transplant (SOT) recipients must be based on genotypic analysis. However, this recommendation is not systematically followed. OBJECTIVES: To assess the presence of mutations associated with CMV resistance in SOT recipients with suspected resistance, their associated risk factors and the clinical impact of resistance. STUDY DESIGN: Using Sanger sequencing we prospectively assessed the presence of resistance mutations in a nation-wide prospective study between September 2013-August 2015. RESULTS: Of 39 patients studied, 9 (23%) showed resistance mutations. All had one mutation in the UL 97 gene and two also had one mutation in the UL54 gene. Resistance mutations were more frequent in lung transplant recipients (44% p=0.0068) and in patients receiving prophylaxis >/=6 months (57% vs. 17%, p=0.0180). The mean time between transplantation and suspicion of resistance was longer in patients with mutations (239 vs. 100days, respectively, p=0.0046) as was the median treatment duration before suspicion (45 vs. 16days, p=0.0081). There were no significant differences according to the treatment strategies or the mean CMV load at the time of suspicion. Of note, resistance-associated mutations appeared in one patient during CMV prophylaxis and also in a seropositive organ recipient. Incomplete suppression of CMV was more frequent in patients with confirmed resistance. CONCLUSIONS: Our study confirms the need to assess CMV resistance mutations in any patient with criteria of suspected clinical resistance. Early confirmation of the presence of resistance mutations is essential to optimize the management of these patients

    Molecular characterization of methicillin-resistant Staphylococcus aureus clinical strains from the endotracheal tubes of patients with nosocomial pneumonia

    Full text link
    Background: Among all cases of nosocomial pneumonia, Staphylococcus aureus is the second most prevalent pathogen (17.8%). In Europe, 29.9% of the isolates are oxacillin-resistant. The changing epidemiology of methicillinresistant Staphylococcus aureus (MRSA) nosocomial infections and the decreasing susceptibility to first-line antibiotics leave clinicians with few therapeutic options. The objective of our study was to determine the antimicrobial susceptibility, the associated molecular mechanisms of resistance and the epidemiological relatedness of MRSA strains isolated from the endotracheal tubes (ETT) of intubated critically ill patients in the intensive care unit (ICU) with nosocomial pneumonia caused by Staphylococcus aureus. Methods: The antimicrobial susceptibility to vancomycin, linezolid, ciprofloxacin, clindamycin, erythromycin, chloramphenicol, fusidic acid, gentamicin, quinupristin-dalfopristin, rifampicin, sulfamethoxazole/trimethoprim, and tetracycline were measured. Resistance mechanisms were then analyzed by polymerase chain reaction and sequencing. Molecular epidemiology was carried out by multi-locus sequence typing. Results: S. aureus isolates were resistant to ciprofloxacin, erythromycin, gentamicin, tetracycline, clindamycin, and fusidic acid. The most frequent mutations in quinolone-resistant S. aureus strains were S84L in the gyrA gene, V511A in the gyrB gene, S144P in the grlA gene, and K401R/E in the grlB gene. Strains resistant to erythromycin carried the ermC, ermA, and msrA genes; the same ermC and ermA genes were detected in strains resistant to clindamycin. The aac(6′)-aph(2″) gene was related to gentamicin resistance, while resistance to tetracycline was related to tetK (efflux pump). The fusB gene was detected in the strain resistant to fusidic acid. The most frequent sequence types were ST22, ST8, and ST217, which were distributed in four clonal complexes (CC5, CC22, CC45, and CC59). Conclusions: High levels of resistance to second-line antimicrobials threatens the treatment of nosocomial respiratory infections due to methicillin-resistant S. aureus with decreased susceptibility to linezolid and vancomycin. The wide genotypic diversity found reinforces the central role of ICU infection control in preventing nosocomial transmission

    Label-Free Plasmonic Biosensor for Rapid, Quantitative, and Highly Sensitive COVID-19 Serology: Implementation and Clinical Validation

    No full text
    Serological tests are essential for the control and management of COVID-19 pandemic, not only for current and historical diagnostics but especially for surveillance, epidemiological, and acquired immunity studies. Clinical COVID-19 serology is routinely performed by enzymatic or chemiluminescence immunoassays (i.e., ELISA or CLIA), which provide good sensitivities at the expense of relatively long turnaround times and specialized laboratory settings. Rapid serological tests, based on lateral flow assays, have also been developed and widely commercialized, but they suffer from limited reliability due to relatively low sensitivity and specificity. We have developed and validated a direct serological biosensor assay employing proprietary technology based on Surface Plasmon Resonance (SPR). The biosensor offers a rapid -less than 15 min- identification and quantification of SARS-CoV-2 antibodies directly in clinical samples, without the need of any signal amplification. The portable plasmonic biosensor device employs a custom-designed multi-antigen sensor biochip, combining the two main viral antigens (RBD peptide and N protein), for simultaneous detection of human antibodies targeting both antigens. The SPR serology assay reaches detection limits in the low ng mL-1 range employing polyclonal antibodies as standard, which are well below the commonly detected antibody levels in COVID-19 patients. The assay has also been implemented employing the first WHO approved anti-SARS-CoV-2 immunoglobulin standard. We have carried out a clinical validation with COVID-19 positive and negative samples (n=120) that demonstrates the excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor device as an accurate, robust, and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the management of COVID-19 patients and for the evaluation of immunological status during vaccination, treatment or in front of emerging variants.<br /
    corecore