Monitoring monkeypox virus in saliva and air samples in Spain: a cross-sectional study

Background: The transmission of monkeypox virus occurs through direct contact, but transmission through saliva or exhaled droplets and aerosols has not yet been investigated. We aimed to assess the presence of monkeypox virus DNA and infectious virus in saliva samples and droplets and aerosols exhaled from patients infected with monkeypox virus. Methods: We did a cross-sectional study in patients with monkeypox confirmed by PCR who attended two health centres in Madrid, Spain. For each patient, we collected samples of saliva, exhaled droplets within a mask, and aerosols captured by air filtration through newly developed nanofiber filters. We evaluated the presence of monkeypox virus in the samples by viral DNA detection by quantitative PCR (qPCR) and isolation of infectious viruses in cell cultures. Findings: Between May 18 and July 15, 2022, 44 patients with symptomatic monkeypox attended two health centres in Madrid and were included in the study. All were cisgender men, with a median age of 35·0 years (IQR 11·3). We identified high loads of monkeypox virus DNA by qPCR in 35 (85%) of 41 saliva samples. Infectious monkeypox virus was recovered from 22 (67%) of 33 saliva samples positive for monkeypox virus DNA. We also found a significant association between the number of affected cutaneous areas or general symptoms and the viral load present in saliva samples. Droplets exhaled from patients with monkeypox, detected inside a mask, contained monkeypox virus DNA in 32 (71%) of 45 samples, with two of the 32 positive samples showing the presence of the infectious virus. Monkeypox virus DNA in aerosols, collected from the medical consultation room, were detected in 27 (64%) of 42 samples, despite patients wearing an FFP2 mask during the visit. Infectious virus was not recovered from aerosol samples. High levels of monkeypox virus DNA were identified in aerosols collected from a hospital isolation room housing a patient with monkeypox. Interpretation: The identification of high viable monkeypox virus loads in saliva in most patients with monkeypox and the finding of monkeypox virus DNA in droplets and aerosols warrants further epidemiological studies to evaluate the potential relevance of the respiratory route of infection in the 2022 monkeypox virus outbreak.This study was funded by the EU (Nextgeneration EU), Consejo Superior de Investigaciones Científicas (PTI Salud Global), and Ciberinfec (Acción estratégica MKPXV22). We thank Milagros Guerra and the Electron Microscopy Service at CBMSO for their support. We thank the contribution of Grupo Viruela Simio Madrid ISCIII/HCSC/Sandoval.S

Detection of Peanut Allergen by Real-Time PCR: Looking for a Suitable Detection Marker as Affected by Processing

Peanut (Arachis hypogaea) contains allergenic proteins, which make it harmful to the sensitised population. The presence of peanut in foods must be indicated on label, to prevent accidental consumption by allergic population. In this work, we use chloroplast markers for specific detection of peanut by real-time PCR (Polymerase Chain Reaction), in order to increase the assay sensitivity. Binary mixtures of raw and processed peanut flour in wheat were performed at concentrations ranging from 100,000 to 0.1 mg/kg. DNA isolation from peanut, mixtures, and other legumes was carried out following three protocols for obtaining genomic and chloroplast-enrich DNA. Quantity and quality of DNA were evaluated, obtaining better results for protocol 2. Specificity and sensitivity of the method has been assayed with specific primers for three chloroplast markers (mat k, rpl16, and trnH-psbA) and Ara h 6 peanut allergen-coding region was selected as nuclear low-copy target and TaqMan probes. Efficiency and linear correlation of calibration curves were within the adequate ranges. Mat k chloroplast marker yielded the most sensitive and efficient detection for peanut. Moreover, detection of mat K in binary mixtures of processed samples was possible for up to 10 mg/kg even after boiling, and autoclave 121 °C 15 min, with acceptable efficiency and linear correlation. Applicability of the method has been assayed in several commercial food products

Detection of Peanut Allergen by Real-Time PCR: Looking for a Suitable Detection Marker as Affected by Processing

15 Pág. Departamento de Tecnología de Alimentos​​Peanut (Arachis hypogaea) contains allergenic proteins, which make it harmful to the sensitised population. The presence of peanut in foods must be indicated on label, to prevent accidental consumption by allergic population. In this work, we use chloroplast markers for specific detection of peanut by real-time PCR (Polymerase Chain Reaction), in order to increase the assay sensitivity. Binary mixtures of raw and processed peanut flour in wheat were performed at concentrations ranging from 100,000 to 0.1 mg/kg. DNA isolation from peanut, mixtures, and other legumes was carried out following three protocols for obtaining genomic and chloroplast-enrich DNA. Quantity and quality of DNA were evaluated, obtaining better results for protocol 2. Specificity and sensitivity of the method has been assayed with specific primers for three chloroplast markers (mat k, rpl16, and trnH-psbA) and Ara h 6 peanut allergen-coding region was selected as nuclear low-copy target and TaqMan probes. Efficiency and linear correlation of calibration curves were within the adequate ranges. Mat k chloroplast marker yielded the most sensitive and efficient detection for peanut. Moreover, detection of mat K in binary mixtures of processed samples was possible for up to 10 mg/kg even after boiling, and autoclave 121 °C 15 min, with acceptable efficiency and linear correlation. Applicability of the method has been assayed in several commercial food products.This research was funded by the Spanish Ministerio de Ciencia e Innovación, Grant No.AGL2017-83082-R.Peer reviewe

Changes Induced by Pressure Processing on Immunoreactive Proteins of Tree Nuts

Tree nuts confer many health benefits due to their high content of vitamins and antioxidants, and they are increasingly consumed in the last few years. Food processing is an important industrial tool to modify allergenic properties of foods, in addition to ensuring safety and enhancing organoleptic characteristics. The effect of high pressure, without and with heating, on SDS-PAGE and immunodetection profile of potential allergenic proteins (anti-11S, anti-2S and anti-LTP) of pistachio, cashew, peanut, hazelnut, almond, and chestnut was investigated. Processing based on heat and/or pressure and ultra-high pressure (HHP, 300–600 MPa) without heating was applied. After treating the six tree nuts with pressure combined with heat, a progressive diminution of proteins with potential allergenic properties was observed. Moreover, some tree nuts proteins (pistachio, cashew, and peanut) seemed to be more resistant to technological processing than others (hazelnut and chestnut). High pressure combined with heating processing markedly reduce tree nut allergenic potential as the pressure and treatment time increases. HHP do not alter hazelnut and almond immunoreactivity

Effect of instant controlled pressure drop (DIC) treatment on the detection of nut allergens by real time PCR

13 Pág.Tree nuts show nutritional properties and human health benefits. However, they contain allergenic proteins, which make them harmful to the sensitised population. The presence of tree nuts on food labelling is mandatory and, consequently, the development of suitable analytical methodologies to detect nuts in processed foods is advisable. Real-Time PCR allowed a specific and accurate amplification of allergen sequences. Some food processing methods could induce structural and/or conformational changes in proteins by altering their allergenic capacity, as well as produce the fragmentation and/or degradation of genomic DNA. In this work, we analysed by means of Real-Time PCR, the influence of pressure and thermal processing through Instant Controlled Pressure Drop (DIC) on the detectability of hazelnut, pistachio and cashew allergens. The detection of targets in hazelnut, pistachio and cashew (Cor a 9, Pis v 1 and Ana o 1, respectively) is affected by the treatment to different extents depending on the tree nut. Results are compared to those previously obtained by our group in the analysis of different treatments on the amplificability of the same targets. Reduction in amplificability is similar to that reported for some autoclave conditions. Our assays might allow for the detection of up to 1000 mg/kg of hazelnut, pistachio and cashew flours after being submitted to DIC treatment in food matrices.This research was funded by the Spanish Ministerio de Ciencia e Innovación, grant number AGL2017-83082-RPeer reviewe

Application of real-time PCR for tree nut allergen detection in processed foods

18 Pág.Currently, food allergies are an important health concern worldwide. The presence of undeclared allergenic ingredients or the presence of traces of allergens due to accidental contamination during food processing poses a great health risk to sensitized individuals. Therefore, reliable analytical methods are required to detect and identify allergenic ingredients in food products. Real-time PCR allowed a specific and accurate amplification of allergen sequences. Some processing methods could induce the fragmentation and/or degradation of genomic DNA and some studies have been performed to analyze the effect of processing on the detection of different targets, as thermal treatment, with and without applying pressure. In this review, we give an updated overview of the applications of real-time PCR for the detection of allergens of tree nut in processed food products. The different variables that contribute to the performance of PCR methodology for allergen detection are also review and discussed.This work was supported by the Plan Nacional I + D + I research projects AGL 2008-03453, AGL 2012-39863 and AGL2017-83082. Ministerio de Ciencia e Innovación.Ojo! Los 2 primeros proyectos normaliza dos diferentes con la misma referencia.Peer reviewe

Effect of Instant Controlled Pressure Drop (DIC) Treatment on the Detection of Nut Allergens by Real Time PCR

Tree nuts show nutritional properties and human health benefits. However, they contain allergenic proteins, which make them harmful to the sensitised population. The presence of tree nuts on food labelling is mandatory and, consequently, the development of suitable analytical methodologies to detect nuts in processed foods is advisable. Real-Time PCR allowed a specific and accurate amplification of allergen sequences. Some food processing methods could induce structural and/or conformational changes in proteins by altering their allergenic capacity, as well as produce the fragmentation and/or degradation of genomic DNA. In this work, we analysed by means of Real-Time PCR, the influence of pressure and thermal processing through Instant Controlled Pressure Drop (DIC) on the detectability of hazelnut, pistachio and cashew allergens. The detection of targets in hazelnut, pistachio and cashew (Cor a 9, Pis v 1 and Ana o 1, respectively) is affected by the treatment to different extents depending on the tree nut. Results are compared to those previously obtained by our group in the analysis of different treatments on the amplificability of the same targets. Reduction in amplificability is similar to that reported for some autoclave conditions. Our assays might allow for the detection of up to 1000 mg/kg of hazelnut, pistachio and cashew flours after being submitted to DIC treatment in food matrices

Changes Induced by Pressure Processing on Immunoreactive Proteins of Tree Nuts

11 Pág.Tree nuts confer many health benefits due to their high content of vitamins and antioxidants, and they are increasingly consumed in the last few years. Food processing is an important industrial tool to modify allergenic properties of foods, in addition to ensuring safety and enhancing organoleptic characteristics. The effect of high pressure, without and with heating, on SDS-PAGE and immunodetection profile of potential allergenic proteins (anti-11S, anti-2S and anti-LTP) of pistachio, cashew, peanut, hazelnut, almond, and chestnut was investigated. Processing based on heat and/or pressure and ultra-high pressure (HHP, 300-600 MPa) without heating was applied. After treating the six tree nuts with pressure combined with heat, a progressive diminution of proteins with potential allergenic properties was observed. Moreover, some tree nuts proteins (pistachio, cashew, and peanut) seemed to be more resistant to technological processing than others (hazelnut and chestnut). High pressure combined with heating processing markedly reduce tree nut allergenic potential as the pressure and treatment time increases. HHP do not alter hazelnut and almond immunoreactivity.This research was funded by the Spanish Ministerio de Ciencia, Innovación y Universidades, grant number AGL2017-83082-RPeer reviewe

Chestnut allergen detection in complex food products: Development and validation of a real-time PCR method

7 Pág.Chestnut is gaining importance as food allergen, but a specific detection method has not been performed so far. For the first time, the development of a real-time PCR assay for chestnut allergen detection in processed foods is described. Initially, three sets of novel primers specific for allergen-encoding genes (Cas s 5, Cas s 9 and Cas s TLP) were designed and evaluated for chestnut detection. Primers for Cas s 9 and a TaqMan probe were finally selected for a sensitive and specific detection of chestnut in binary mixtures with a practical limit of detection (LOD) of 100 ppm. Effect of processing has been evaluated and sensitivity slightly reduced after boiling treatment. Amplification of Cas s 9 was importantly affected when heat and pressure were applied (autoclaving). Applicability of the method was tested by analysis of commercial food products. Consequently, the results support the development and validation of a real-time PCR method for accurate chestnut allergen detection and labelling.This study has been supported by the Plan Nacional I+D+I [grant numbers AGL2012-39863, AGL2017-83082]. AS is grateful to her Predoctoral contract from the Ministerio de Ciencia, Innovación y Universidades [reference BES2013-065833].Peer reviewe

Mitigation of peanut allergenic reactivity by combined processing: Pressured heating and enzymatic hydrolysis

11 Pág.Among food allergens, peanut is one of the most critical. This study evaluates peanut allergenic features after the combination of heat, pressure, and enzymatic digestion under sonication, by immunodetection using serum IgE of sensitized patients and mass-spectroscopy. In the studied population, there was a predominance of patients with sensitization to Ara h 9 (nsLTP) followed by sensitization to seed storage proteins (Sprot, Ara h 1, 2, 3, and 6). The Sprot sensitized patients showed higher reactivity. The enzyme E5 was efficient for inducing protein fragmentation and allergenic reactivity reduction when it was used combined with pressured heating treatments such as autoclave and Controlled Instantaneous Depressurization (DIC). Only a few Ara h 1 and Ara h 3 peptides were identified after enzymatic digestion of DIC peanut samples. The combination of pressured heating treatments and enzymatic hydrolysis was the most efficient method to strongly mitigate or even eliminate the allergenic potential of peanut. Our findings set a possibility for a group of patients in which their allergy could be treated with a processed less-allergenic peanut and consequently less risky, more easy and quicker desensitization treatment. Industrial relevance: The findings identify innovative thermal, pressure and enzymatic processing conditions highly effective to mitigate or even abolish the allergenic potency of peanut, which may be relevant for consumers, clinicians, regulatory agencies and the food industry. The applications of processed peanut with reduced IgE binding potency for tolerance induction might be a convenient strategy.This work was supported by Plan Nacional I + D + i research projects [AGL2017–83082-R and PID2021-122942OB-I00].Peer reviewe