Plasma-induced nanoparticle aggregation for stratifying COVID-19 patients according to disease severity.

Stratifying patients according to disease severity has been a major hurdle during the COVID-19 pandemic. This usually requires evaluating the levels of several biomarkers, which may be cumbersome when rapid decisions are required. In this manuscript we show that a single nanoparticle aggregation test can be used to distinguish patients that require intensive care from those that have already been discharged from the intensive care unit (ICU). It consists of diluting a platelet-free plasma sample and then adding gold nanoparticles. The nanoparticles aggregate to a larger extent when the samples are obtained from a patient in the ICU. This changes the color of the colloidal suspension, which can be evaluated by measuring the pixel intensity of a photograph. Although the exact factor or combination of factors behind the different aggregation behavior is unknown, control experiments demonstrate that the presence of proteins in the samples is crucial for the test to work. Principal component analysis demonstrates that the test result is highly correlated to biomarkers of prognosis and inflammation that are commonly used to evaluate the severity of COVID-19 patients. The results shown here pave the way to develop nanoparticle aggregation assays that classify COVID-19 patients according to disease severity, which could be useful to de-escalate care safely and make a better use of hospital resources.

Colorimetric Detection of Sepsis-Derived Hyperdegranulation with Plasmonic Nanosensors.

Hyperdegranulation of neutrophilic granulocytes is a common finding in sepsis that directly contributes to the heightened immune response leading to organ dysfunction. Currently, cell degranulation is detected by flow cytometry, which requires large infrastructure that is not always available at the point of care. Here, we propose a plasmonic assay for detecting the degranulation status of septic cells colorimetrically. It is based on triggering the aggregation of gold nanoparticles with cationic granule proteins. Cells from septic patients contain fewer granules and therefore release less cationic proteins than healthy cells. This results in red-colored assays than can be easily detected by eye. The assay can selectively detect cationic granule proteins even in the presence of an excess of unrelated proteins, which is key to detect degranulation with high specificity. Coupling this signal generation mechanism with a magnetic purification step enabled the identification of septic cells with the same performance as flow cytometry. This makes the proposed method a promising alternative for diagnosing sepsis in decentralized healthcare schemes.

Optimized detection of lung IL-6 via enzymatic liquefaction of low respiratory tract samples: application for managing ventilated patients.

Lung IL-6 is a promising biomarker for predicting respiratory failure during pulmonary infections. This biomarker is found in respiratory samples which need to be liquefied prior to analysis. Traditional liquefying methods use reducing agents such as dithiothreitol (DTT). However, DTT impairs immunodetection and does not liquefy highly viscous samples. We propose an enzymatic method that liquefies samples by means of generating O2 bubbles with endogenous catalase. Low respiratory tract specimens from 48 mechanically ventilated patients (38 with SARS-CoV-2 infection) were treated with DTT or with the enzymatic method. We used turbidimetry to compare the liquefaction degree and IL-6 was quantified with ELISA. Finally, we used AUC-ROC, time-to-event and principal component analysis to evaluate the association between respiratory compromise or local inflammation and IL-6 determined with both methods. Enzymatically treated samples were better liquefied than those reduced by DTT, which resulted in higher ELISA signals. Lung IL-6 levels obtained with the enzymatic procedure were negatively correlated with the oxygenation index (PaO2/FiO2) and the time of mechanical ventilation. The proposed enzymatic liquefaction method improves the sensitivity for lung IL-6 detection in respiratory samples, which increases its predictive power as a biomarker for evaluating respiratory compliance.

Nanoparticle transfer biosensors for the non-invasive detection of SARS-CoV-2 antigens trapped in surgical face masks.

Detecting SARS-CoV-2 antigens in respiratory tract samples has become a widespread method for screening new SARS-CoV-2 infections. This requires a nasopharyngeal swab performed by a trained healthcare worker, which puts strain on saturated healthcare services. In this manuscript we describe a new approach for non-invasive COVID-19 diagnosis. It consists of using mobile biosensors for detecting viral antigens trapped in surgical face masks worn by patients. The biosensors are made of filter paper containing a nanoparticle reservoir. The nanoparticles transfer from the biosensor to the mask on contact, where they generate colorimetric signals that are quantified with a smartphone app. Sample collection requires wearing a surgical mask for 30 min, and the total assay time is shorter than 10 min. When tested in a cohort of 27 patients with mild or no symptoms, an area under the receiving operating curve (AUROC) of 0.99 was obtained (96.2 % sensitivity and 100 % specificity). Serial measurements revealed a high sensitivity and specificity when masks were worn up to 6 days after diagnosis. Surgical face masks are inexpensive and widely available, which makes this approach easy to implement anywhere. The excellent sensitivity, even when tested with asymptomatic patient samples, along with the mobile detection scheme and non-invasive sampling procedure, makes this biosensor design ideal for mass screening.

Low Albumin Levels Are Associated with Poorer Outcomes in a Case Series of COVID-19 Patients in Spain: A Retrospective Cohort Study.

There is limited information available describing the clinical and epidemiological features of Spanish patients requiring hospitalization for coronavirus disease 2019 (COVID-19). In this observational study, we aimed to describe the clinical characteristics and epidemiological features of severe (non-ICU) and critically patients (ICU) with COVID-19 at triage, prior to hospitalization. Forty-eight patients (27 non-ICU and 21 ICU) with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were analyzed (mean age, 66 years, [range, 33-88 years]; 67% males). There were no differences in age or sex among groups. Initial symptoms included fever (100%), coughing (85%), dyspnea (76%), diarrhea (42%) and asthenia (21%). ICU patients had a higher prevalence of dyspnea compared to non-ICU patients (95% vs. 61%, p = 0.022). ICU-patients had lymphopenia as well as hypoalbuminemia. Lactate dehydrogenase (LDH), C-reactive protein (CRP), and procalcitonin were significantly higher in ICU patients compared to non-ICU (p < 0.001). Lower albumin levels were associated with poor prognosis measured as longer hospital length (r = -0.472, p < 0.001) and mortality (r = -0.424, p = 0.003). As of 28 April 2020, 10 patients (8 ICU and 2 non-ICU) have died (21% mortality), and while 100% of the non-ICU patients have been discharged, 33% of the ICU patients still remained hospitalized (5 in ICU and 2 had been transferred to ward). Critically ill patients with COVID-19 present lymphopenia, hypoalbuminemia and high levels of inflammation.

Protocolo informático de manejo integral de la sepsis. Descripción de un sistema de identificación precoz / Computerised sepsis protocol management. Description of an early warning system

Introducción: Es preciso desarrollar nuevas estrategias que permitan una identificación precoz y una inmediata instauración de medidas efectivas en el abordaje de la sepsis. La unidad multidisciplinar de sepsis (UMS) desarrolló una herramienta: el Protocolo Informático de Manejo Integral de la Sepsis (PIMIS). El objetivo de este estudio es evaluar la intervención de la UMS y la utilidad del PIMIS. Métodos: Se analizaron las intervenciones según fueran realizadas por consulta directamente solicitada (activación de PIMIS o consulta telefónica) o no solicitada (aislamientos microbiológicos y el Sistema Informático de Detección de Constantes Vitales [SIDCV]), los servicios, el tipo de infección, la recomendación de cambio de antibiótico y el grado de aceptación. Resultados: De las 1.581 consultas, el 65,1% se solicitaron directamente: un 84,1% por activación del PIMIS por el médico responsable y un 15,9% por contacto telefónico directo. Entre las consultas no solicitadas, el 95,2% procedían de microbiología y el 4,8% del SIDCV. Las consultas directamente solicitadas se realizaron más precozmente que las no solicitadas (5,63días vs. 8,47días; p<0,001) y la frecuencia fue mayor en los servicios médicos frente a los quirúrgicos (73,0% vs. 39,1%; p<0,001). Se recomendó un cambio de antibiótico en el 32% de las primeras consultas y se aceptó en el 78,1% de los casos. Conclusiones: La elevada proporción de consultas directamente solicitadas y aceptación de las recomendaciones demuestra que la intervención de la UMS es valorada y respetada. El PIMIS es el principal mecanismo de consulta, lo que lo convierte en una herramienta útil y conveniente para la identificación precoz y el abordaje de la sepsis (AU)

Introduction: New strategies need to be developed for the early recognition and rapid response for the management of sepsis. To achieve this purpose, the Multidisciplinary Sepsis Team (MST) developed the Computerised Sepsis Protocol Management (PIMIS). The aim of this study was to evaluate the convenience of using PIMIS, as well as the activity of the MST. Methods: An analysis was performed on the data collected from solicited MST consultations (direct activation of PIMIS by attending physician or telephone request) and unsolicited ones (by referral from the microbiology laboratory or an automatic referral via the hospital vital signs recording software [SIDCV]), as well as the hospital department, source of infection, treatment recommendation, and acceptance of this. Results: Of the 1,581 first consultations, 65.1% were solicited consultations (84.1% activation of PIMIS and 15.9% by telephone). The majority of unsolicited consultations were generated by the microbiology laboratory (95.2%), and 4.8% from the SIDCV. Referral from solicited consultations were generated sooner (5.63days vs 8.47days; P<.001) and came from clinical specialties rather than from the surgical ward (73.0% vs 39.1%; P<.001). A recommendation was made for antimicrobial prescription change in 32% of first consultations. The treating physician accepted 78.1% of recommendations. Conclusions: The high rate of solicited consultations and acceptance of recommended prescription changes suggest that a MST is seen as a helpful resource, and that PIMIS software is perceived to be useful and convenient to use, as it is the main source of referral (AU)

Computerised sepsis protocol management. Description of an early warning system. / Protocolo informático de manejo integral de la sepsis. Descripción de un sistema de identificación precoz.

INTRODUCTION: New strategies need to be developed for the early recognition and rapid response for the management of sepsis. To achieve this purpose, the Multidisciplinary Sepsis Team (MST) developed the Computerised Sepsis Protocol Management (PIMIS). The aim of this study was to evaluate the convenience of using PIMIS, as well as the activity of the MST. METHODS: An analysis was performed on the data collected from solicited MST consultations (direct activation of PIMIS by attending physician or telephone request) and unsolicited ones (by referral from the microbiology laboratory or an automatic referral via the hospital vital signs recording software [SIDCV]), as well as the hospital department, source of infection, treatment recommendation, and acceptance of this. RESULTS: Of the 1,581 first consultations, 65.1% were solicited consultations (84.1% activation of PIMIS and 15.9% by telephone). The majority of unsolicited consultations were generated by the microbiology laboratory (95.2%), and 4.8% from the SIDCV. Referral from solicited consultations were generated sooner (5.63days vs 8.47days; P<.001) and came from clinical specialties rather than from the surgical ward (73.0% vs 39.1%; P<.001). A recommendation was made for antimicrobial prescription change in 32% of first consultations. The treating physician accepted 78.1% of recommendations. CONCLUSIONS: The high rate of solicited consultations and acceptance of recommended prescription changes suggest that a MST is seen as a helpful resource, and that PIMIS software is perceived to be useful and convenient to use, as it is the main source of referral.

Diseminación nosocomial de Staphylococcus hominis resistente al linezolid en dos hospitales de Mallorca / Nosocomial spread of linezolid-resistant Staphylococcus hominis intwohospitals in Majorca

Introducción A partir del 2008 se detectaron varios aislados de Staphylococcus hominis (S. hominis) multirresistentes, incluyendo resistencia al linezolid y a la teicoplanina, en pacientes ingresados en dos hospitales de Mallorca. Por ello, se inició un estudio para determinar la epidemiología molecular y el mecanismo de resistencia al linezolid. Métodos El estudio de epidemiología molecular se realizó mediante electroforesis en campo pulsado (ECP), tras digestión con ApaI. Se efectuó amplificación de un fragmento de los genes ARNr 23S (con secuenciación posterior) y cfr. Resultados Desde marzo de 2008 hasta febrero de 2009 se detectaron 15 aislados de S. hominis resistentes al linezolid y a la teicoplanina, procedentes de 14 pacientes. Todos ellos excepto uno habían ingresado en las Unidades de Cuidados Intensivos de alguno de los dos hospitales. La mayoría de los aislados (9) se obtuvieron en hemocultivos. Gran parte de los pacientes infectados (12 de los 15 episodios infecciosos, el 80,0%) recibieron pautas de linezolid antes de la detección del aislado resistente. La ECP reveló la presencia de un único clon entre los aislados de S. hominis resistentes al linezolid. Se detectó la mutación G2576T en todas las cepas resistentes, mientras que la PCR del gen cfr fue negativa en las mismas. Todos los aislados fueron también resistentes a la penicilina, oxacilina, trimetoprim-sulfametoxazol, ciprofloxacino, levofloxacino y tobramicina; y sensibles a la eritromicina, tetraciclina, gentamicina y daptomicina. La CMI a la vancomicina fue de 4μg/ml en todos ellos. Conclusiones La detección de cepas de estafilococos resistentes al linezolid resalta la necesidad de racionalizar el uso del linezolid y mantener un control activo de dicha resistencia con objeto de preservar la utilidad clínica de este antimicrobiano (AU)

Objective: Since March 2008, several linezolid and teicoplanin-resistant Staphylococcus hominis (S. hominis)isolates have been recovered from patients admitted to the two major hospitals on the island of Majorca, Spain. For this reason, a study was conducted to determine the molecular epidemiology of these isolates and the mechanism of linezolid resistance. Methods: The molecular epidemiology study was performed by pulsed-field gel electrophoresis (PFGE)analysis, after digestion with ApaI. Linezolid resistance mechanisms were evaluated by PCR amplification of a fragment of the domain V of the 23S rRNA gene (followed by sequencing) and cfr gene. Results: From March 2008 to February 2009, 15 linezolid and teicoplan in-resistant S. hominis isolates were recovered from 14 patients. All of them, except one, were hospitalised in the intensive care units of either of the two institutions. Isolates were obtained mainly from blood cultures (9). The majority of infected patients (12 of 15 infectious episodes, 80.0%) had received courses of linezolid prior to detection of the resistant isolate. PFGE analysis revealed the presence of a unique clone among linezolid resistant S. hominisisolates. The G2576T mutation was detected in all the linezolid resistant strains. None of the resistant isolates showed a positive PCR for the cfr gene. All of the isolates were also resistant to penicillin, oxacillin, trimethoprim-sulfamethoxazole, ciprofloxacin, levofloxacin, and tobramicin; whereas all of them were susceptible to erythromycin, tetracycline, gentamicin, and daptomycin. The MIC of vancomycin was4 g/ml for all the strains. Conclusions: The detection of linezolid resistant Staphylococci highlights the need to rationalise the use of linezolid, and maintain an active surveillance of its resistance to preserve the clinical usefulness of this antimicrobial (AU)

[Nosocomial spread of linezolid-resistant Staphylococcus hominis in two hospitals in Majorca]. / Diseminación nosocomial de Staphylococcus hominis resistente al linezolid en dos hospitales de Mallorca.

OBJECTIVE: Since March 2008, several linezolid and teicoplanin-resistant Staphylococcus hominis (S. hominis) isolates have been recovered from patients admitted to the two major hospitals on the island of Majorca, Spain. For this reason, a study was conducted to determine the molecular epidemiology of these isolates and the mechanism of linezolid resistance. METHODS: The molecular epidemiology study was performed by pulsed-field gel electrophoresis (PFGE) analysis, after digestion with ApaI. Linezolid resistance mechanisms were evaluated by PCR amplification of a fragment of the domain V of the 23S rRNA gene (followed by sequencing) and cfr gene. RESULTS: From March 2008 to February 2009, 15 linezolid and teicoplanin-resistant S. hominis isolates were recovered from 14 patients. All of them, except one, were hospitalised in the intensive care units of either of the two institutions. Isolates were obtained mainly from blood cultures (9). The majority of infected patients (12 of 15 infectious episodes, 80.0%) had received courses of linezolid prior to detection of the resistant isolate. PFGE analysis revealed the presence of a unique clone among linezolid resistant S. hominis isolates. The G2576T mutation was detected in all the linezolid resistant strains. None of the resistant isolates showed a positive PCR for the cfr gene. All of the isolates were also resistant to penicillin, oxacillin, trimethoprim-sulfamethoxazole, ciprofloxacin, levofloxacin, and tobramicin; whereas all of them were susceptible to erythromycin, tetracycline, gentamicin, and daptomycin. The MIC of vancomycin was 4µg/ml for all the strains. CONCLUSIONS: The detection of linezolid resistant Staphylococci highlights the need to rationalise the use of linezolid, and maintain an active surveillance of its resistance to preserve the clinical usefulness of this antimicrobial.

The ventilator-associated pneumonia PIRO score: a tool for predicting ICU mortality and health-care resources use in ventilator-associated pneumonia.

BACKGROUND: No score is available to assess severity and stratify mortality risk in ventilator-associated pneumonia (VAP). Our objective was to develop a severity assessment tool for VAP patients. METHODS: A prospective, observational, cohort study was performed including 441 patients with VAP in three multidisciplinary ICUs. Multivariate logistic regression was performed to identify variables independently associated with ICU mortality. Results were converted into a four-variable score based on the PIRO (predisposition, insult, response, organ dysfunction) concept for ICU mortality risk stratification in VAP patients. RESULTS: Comorbidities (COPD, immunocompromise, heart failure, cirrhosis, or chronic renal failure); bacteremia; systolic BP < 90 mm Hg; and ARDS. A simple, four-variable VAP PIRO score was obtained at VAP onset. Mortality varied significantly according to VAP PIRO score (p < 0.001). On the basis of observed mortality for each VAP PIRO score, patients were stratified into three levels of risk: (1) mild, 0 to 1 points; (2) high, 2 points; (3) very high, 3 to 4 points. VAP PIRO score was associated with higher risk of death in Cox regression analysis in the high-risk group (hazard ratio, 2.14; 95% confidence interval [CI], 1.19 to 3.86) and the very-high-risk group (hazard ratio, 4.63; 95% confidence interval, 2.68 to 7.99). Moreover, medical resource use after VAP diagnosis was higher in high-risk and very-high-risk levels compared to patients at mild risk, evaluated using length of ICU stay (mean +/- SD, 22.0 +/- 10.6 d vs 18.7 +/- 12.8 d, p < 0.05) and duration of mechanical ventilation (18.3 +/- 10.1 d vs 15.1 +/- 11.5 d, p < 0.05). CONCLUSIONS: VAP PIRO score is a simple, practical clinical tool for predicting ICU mortality and health-care resources use that is likely to assist clinicians in determining VAP severity.