Predicting concentrations of volatile and semi-volatile compounds in indoor areas through analysis of condensed water samples. A proof of concept.

Atmospheres from indoor areas contain a range of volatile and semi-volatile compounds to which inhabitants are exposed through breathing. Despite different qualitative approaches have been proposed for the identification of compounds associated to the vapor phase of confined areas, active sampling remains as the preferred technique when quantitative data is required. Herein, we investigate the correlations existing between concentrations in air and water condensates obtained from indoor areas. To this end, samples of both matrices were simultaneously collected and analyzed by gas chromatography mass spectrometry. After validation of sample concentration approaches for a selection of compounds, the effect of different operational conditions, and environmental variables, in their concentrations in condensed water was assessed. Levels in this matrix were hardly affected by sampling time, air flow through the dehumidifier device, and the environmental temperature and humidity. Thus, air water distribution coefficients (Kaw) could be estimated for fourteen out of sixteen pre-selected compounds. These values permitted a semiquantitative evaluation of their concentrations existing in air from different areas. In case of semi-volatile compounds (i.e. phenol, benzothiazole, phthalates), with log Kaw below -4.8, analysis of 50 mL water samples permitted to achieve lower limits of quantification than active air sampling for 3 h at a flowrate of 1 m3 h-1.

Assessment of the occurrence and interaction between pesticides and plastic litter from vineyard plots.

In this research, aged plastic fragments collected from vineyards were characterized in terms of composition, residues of pesticides, and their potential to exchange these compounds with the aquatic media. To this end, we employed the qualitative and quantitative information provided by complementary analytical techniques, including chromatography, organic and inorganic mass spectrometry, infrared spectroscopy and electronic microscopy. Debris of weathered plastics were identified as polypropylene and polyethylene, containing different types of additives, from organic UV stabilizers to inorganic fillers, such as calcium salts. Regardless of polymer type, plastic litter collected from vineyards contained residues of pesticides, and particularly of fungicides, with total concentrations in the range of values from 114 ng g-1 to 76.4 µg g-1. Data obtained under different extraction conditions suggested that a fraction of these compounds was absorbed in aged polymers, penetrating inside the material. The parallel analysis of plastic litter and vineyard soils reflected higher pesticide residues in the former matrix. Furthermore, several fungicides, considered as labile in vineyard soils (i.e. zoxamide and folpet), were those showing the highest levels in plastic litter. Simulated sorption-desorption studies, with plastic debris in contact with surface water, demonstrated the higher affinity of aged materials by moderately polar pesticides than their new counterparts. For the first time, the manuscript highlights the presence of plastic litter in vineyards soils, reflecting the accumulation of several fungicides in this matrix, in some cases, with a different stability pattern to that observed in the soil from same vineyards.

Occurrence and risk assessment of pesticides and pharmaceuticals in viticulture impacted watersheds from Northwest Spain.

An automated analytical methodology was developed, validated and applied to monitor 73 organic pollutants (pesticides and pharmaceuticals) in surface and groundwater samples obtained in watersheds from an intensive viticulture, rural region, in the Northwest of Spain. Filtered samples were concentrated using a reusable solid-phase extraction sorbent, on-line combined with liquid chromatography tandem mass spectrometry (LC-MS/MS). The analytical procedure achieved limits of quantification between 1 ng L-1 and 10 ng L-1, with a throughput of 2 samples hour-1, providing accurate recoveries for more than 90% of the 73 selected compounds, using calibration solutions prepared in ultrapure water (in presence of methanol and formic acid) as neat solvent. The distribution and the concentrations of pesticides in small streams impacted by discharges of treated municipal wastewaters were different in rural and residential areas. On the other hand, pharmaceuticals showed a similar distribution in both streams. In surface waters from viticulture impacted watersheds, with a limited influence of municipal wastewaters, pulses of pesticides were noticed, with values above 100 ng L-1 for several fungicides. Cardiovascular pharmaceuticals, psychiatric drugs and/or their transformation products were also ubiquitous in these samples, with low, but relatively stable concentrations among sampling campaigns. Within the suite of investigated compounds, maximum pesticide residues remained below their predicted-non effect concentration (PNEC) in all samples. On the other hand, the environmental concentrations of the cardiovascular drug olmesartan stayed systematically above its PNEC in fresh water samples.

Basic micro-pollutants in sludge from municipal wastewater treatment plants in the Northwest Spain: Occurrence and risk assessment of sludge disposal.

Sludge is one of the most problematic residues generated during wastewater treatment. Herein, we validate a single-step, sensitive procedure for the determination of a selection of 46 basic micro-pollutants, either used as pharmaceuticals or pesticides, in sludge from municipal sewage treatment plants (STPs), using liquid chromatography tandem mass spectrometry as determination technique. The proposed method permitted to achieve accurate recoveries (values from 70% to 120%, for samples spiked at different concentration levels) using solvent-based calibration standards. This feature, combined with limits of quantification lower than 5 ng g-1 (dry weight), allowed the rapid and sensitive quantification of target compounds in freeze-dried sludge samples. Out of 46 investigated pollutants, 33 species showed detection frequencies above 85% in a group of 48 sludge samples, obtained from 45 STPs located in the Northwest of Spain. The assessment of eco-toxicological risks associated to sludge disposal as fertilizer in agriculture and/or forestry, considering average concentrations found in sludge samples, highlighted eight pollutants (sertraline, venlafaxine, N-desethyl amiodarone, amiodarone, norsertraline, trazodone, amitriptyline and ketoconazole) representing an environmental hazard based on ratios between predicted soil levels and non-effect concentrations estimated using the equilibrium partition method.

Comprehensive characterization of volatile and semi-volatile compounds in e-liquids for electronic cigarette using gas chromatography accurate mass spectrometry.

The consumption of electronic cigarettes is a habit with an increasing prevalence, particularly among youths. Knowing the composition of e-liquids used in these devices represents the first step to understand the potential impact of e-smoking in the health of consumers. Herein, a non-target screening methodology was applied to the identification of volatile and semi-volatile compounds in a set of e-liquids from different suppliers, with different flavors, and containing different kinds of additives, such as nicotine or cannabidiol. To this end, samples were characterized by gas chromatography accurate mass spectrometry, using a time-of-flight mass analyzer. Combination of deconvoluted electronic ionization mass spectra with linear retention index values, obtained for two columns with different selectivity, permitted the identification of more than 250 chemicals with different confidence levels. Among them, respiratory pro-inflammatory compounds, acetals of propylene glycol and glycerin with aldehydes, nicotine-related and non-related alkaloids, and psychoactive cannabinoids were confirmed as concerning compounds in e-liquid samples. Concentration ratios between propylene glycol acetals and parent aldehydes varied in the range from 2% (ethyl vanillin) to more than 80% (case of benzaldehyde). The ratios between the concentrations of delta-9-tetrahydrocannabinol and cannabidiol in e-liquids stayed in the range from 0.02% to 0.3%.

Supercritical fluid chromatography time-of-flight mass spectrometry enantiomeric determination of basic drugs in sewage samples.

Many pharmacologically active compounds are chiral species, and their therapeutic or toxicological effects might differ between isomers. Herein, we develop a fast and sensitive chiral analysis methodology for the determination of eight pharmaceuticals, considered as emerging environmental pollutants and belonging to two different chemical classes, in wastewater and sludge samples. Compounds were separated using supercritical fluid chromatography (SFC) combined with time-of-flight mass spectrometry (TOF-MS) detection. The stationary phase, the modifier and the additive combined with supercritical carbon dioxide (CO2), in the SFC mobile phase, played a major effect in the enantiomeric resolution of selected compounds. Moreover, the composition of the mobile phase affected their ionization efficiency in the electrospray ionization source. Methanol (MeOH), containing a 0.1% of ammonia, was used as CO2 modifier for the separation of compounds in a polysaccharide-type column. Total analysis time was 15.5 min, achieving resolution factors between 1.03 and 2.49 for the eight pairs of enantiomers. In combination with mixed-mode solid-phase extraction and matrix solid-phase dispersion protocols, compounds were determined in wastewater and sludge samples, with limits of quantification in the range of 0.010-0.020 µg L-1 and 3.7-11.1 ng g-1, for aqueous and solid samples, respectively. The amine-type drugs (tramadol, propranolol and venlafaxine) were mostly found in wastewater samples, whilst azolic antimycotics were mainly quantified in sludge. The first group of compounds showed enantiomeric fractions significantly different to those existing in the commercial counterpart pharmaceuticals.

Solid-phase extraction and fractionation of multiclass pollutants from wastewater followed by liquid chromatography tandem-mass spectrometry analysis.

Herein, we describe a modular solid-phase extraction (SPE) setup, combining three sorbents, for the effective extraction of neutrals, acidic, and basic micropollutants from wastewater, followed by their further elution in three independent extracts. The performance of this approach was demonstrated for a suite of 64 compounds, corresponding to different chemical families, using liquid chromatography tandem-mass spectrometry (LC-MS/MS). Target compounds were effectively extracted from wastewater samples; moreover, 62 out of 64 species were isolated in just one of the three fractions (neutrals, acids, and bases) obtained from the combination of sorbents. Globally, the efficiency and the selectivity of the SPE methodology improved the features obtained using generic SPE polymers, displaying just reversed-phase interactions. The overall recoveries of the analytical method, calculated against solvent-based calibration standards, stayed between 80 and 120% for 57 and 60 compounds, in raw and treated wastewater, respectively. Procedural limits of quantification (LOQs) varied from 1 to 20 ng L-1. Analysis of urban wastewater samples identified a group of 19 pollutants showing either negligible median removal efficiencies (± 20%) during wastewater treatment, or even a noticeable enhancement (case of the biodegradation product of the drug valsartan), which might be useful as markers of wastewater discharges in the aquatic environment.

Approaches to liquid chromatography tandem mass spectrometry assessment of glyphosate residues in wine.

The performance of two different analytical methodologies to investigate the presence of glyphosate (GLY) and aminomethylphosphonic acid (AMPA) residues in wine samples was evaluated. Transformation of compounds in their fluorene-9-methyloxycarbonyl derivatives permitted their separation under reversed-phase liquid chromatography with tandem mass spectrometry (LC-MS/MS) determination. Although the wine matrix severely impaired the efficiency of GLY derivatization, this drawback was solved using a molecularly imprinted sorbent for the previous, selective extraction of GLY and AMPA from wine. Alternatively, the use of a strong anionic exchange, polyvinyl alcohol-based LC column, turned to be the most effective alternative for direct determination of both compounds in diluted wine samples. The chromatographic behavior of this column and the magnitude of matrix effects observed during analysis of diluted wine samples were significantly affected by the composition of the mobile phase. Under final working conditions, this column permitted the separation of AMPA and the fungicide fosetyl (which shows common transitions in tandem MS/MS methods), it improved significantly the sample throughput versus extraction-derivatization-purification method, and it allowed the use of solvent-based calibration standards. Both analytical procedures provided similar limits of quantification (LOQs) for GLY (0.5-1.0 ng mL-1), while the multistep method was 8 times more sensitive to AMPA than the direct procedure. GLY residues stayed above method LOQs in 70% of the processed wines; however, concentrations measured in 95% of positive samples remained 100 times below the maximum residue limit (MRL) set for GLY in vinification grapes.

Assessment of direct analysis in real time accurate mass spectrometry for the determination of triclosan in complex matrices.

In this work, the applicability of direct analysis in real time coupled to accurate mass spectrometry (DART-MS) to the quantitative determination of triclosan (TCS) in samples with increasing complexity, from personal care products to extracts from sewage, is investigated. In the first term, DART-MS spectra of TCS as free phenol and as derivatized species are characterized; thereafter, the effects of several instrumental variables in the detectability of TCS (i.e., temperature, solvent, and compound holder) are discussed. Under final selected conditions, TCS was determined from its [M-H]- ions, without need of derivatization, attaining an instrumental limit of quantification of 5 ng mL-1, with a linear response range up to 1000 ng mL-1. Complex matrices, such as solid-phase extracts obtained from environmental water samples, moderately inhibited the ionization efficiency of TCS, with signal attenuation percentages in the range of 6 to 57%, depending on the sample type and on the concentration factor provided by the SPE procedure. The accuracy of results obtained by DART-MS was evaluated using liquid chromatography (LC) with MS detection; in both cases, a time-of-flight (TOF) MS instrument was employed for the selective determination of the [M-H]- ions of TCS (m/z values 286.9439 and 288.9410) using a mass window of 20 ppm. DART-MS did not only provide enough sensitivity to detect the presence of TCS in environmental samples (raw and treated wastewater as well as freeze-dried sludge), but also measured concentrations matched those determined by LC-ESI-TOF-MS, with only slightly higher standard deviations. During analysis of personal care products, containing much higher concentrations of TCS in a less complex matrix, both techniques were equivalent in terms of accuracy and precision. Graphical abstract.

Supercritical fluid chromatography-mass spectrometric determination of chiral fungicides in viticulture-related samples.

Supercritical fluid chromatography (SFC), combined with mass spectrometry (MS), was employed for the determination of five chiral fungicides, from two different chemical families (acylalanine and triazol) in wine and vineyard soils. The effect of different SFC parameters (stationary phase, chiral selector, mobile phase modifier and additive) in the resolution between enantiomers and in the efficiency of compounds ionization at the electrospray source (ESI) was thorougly described. Under final working conditions, chiral separations of selected fungicides were achieved using two different SFC-MS methods, with an analysis time of 10 min and resolution factors from 1.05 to 2.45 between enantiomers. In combination with solid-phase extraction and pressurized liquid extraction, they permitted the enantiomeric determination of target compounds in wine and vineyard soils with limits of quantification in the low ppb range (between 0.5 and 2.5 ng mL-1, and from 1.3 to 6.5 ng g-1, for wine and soil, respectively), and overall recoveries above 80%, calculated using solvent-based standards. For azolic fungicides (tebuconazole, myclobutanil and penconazole) soil dissipation and transfer from vines to wines were non-enantioselective processes. Data obtained for acylalanine compounds confirmed the application of metalaxyl (MET) to vines as racemate and as the R-enantiomer. The enantiomeric fractions (MET-S/(MET-S+MET-R)) of this fungicide in vineyard soils varied from 0.01 to 0.96; moreover, laboratory degradation experiments showed that the relative dissipation rates of MET enantiomers varied depending on the type of soil.

Identification and determination of emerging pollutants in sewage sludge driven by UPLC-QTOF-MS data mining.

Sludge from sewage treatment plants (STPs) is recognized as a sink of moderate to high lipophilic compounds resistant to biodegradation. Herein, we investigate the presence of emerging pollutants in sewage sludge combining the information provided by mass spectrometry detection, following ultra-performance liquid chromatography (UPLC), with the use of an accurate spectral database of pesticides and pharmaceuticals. In a first step, the performance of matrix solid-phase dispersion, as sample preparation technique, and two non-target data acquisition strategies (data dependent, DDA, and data independent analysis modes, DIA), used in combination with a UPLC quadrupole time-of-flight system, are assessed using a selection of deuterated compounds added either to freeze-dried sludge samples, or to sludge extracts. Possibilities and limitations of both modes are discussed. Following the DDA approach, a group of 68 micropollutants was identified in sludge from different STPs. Some of them are reported in this compartment for the first time. Finally, semi-quantitative concentration data are reported for a group of 37 pollutants in samples obtained from 16 STPs. Out of them, 10 pharmaceuticals, showing detection frequencies and median sludge residues above 50% and 100 ng g-1, respectively; are highlighted as pollutants to be monitored in sludge in order to understand their behaviour during the wastewater treatment.

Assessment of UV combined with free chlorine for removal of valsartan acid from water samples.

Valsartan acid (VALA) is a persistent and mobile pollutant, ubiquitously distributed in the aquatic environment. Herein, we assessed the efficiency of UV/free chlorine for the removal of this pollutant. Degradation experiments were performed using different water samples, considering several pH values and concentrations of inorganic anions. Time-course of VALA was measured by injection of different reaction time aliquots in a liquid chromatography (LC) triple quadrupole (QqQ) mass spectrometry (MS) system, whilst the study of potential transformation products (TPs) was evaluated by LC combined with a hybrid quadrupole time-of-flight (QTOF) MS system. Formation of volatile disinfection by-products (DBPs) was investigated by gas chromatography (GC) with TOF-MS detection. Compared to free chlorine treatment and UV photolysis, the combination of both parameters significantly enhanced the degradability of VALA. At neutral pH, UV/free chlorine was also more effective than UV/H2O2 to remove VALA from spiked water solutions. Three TPs of VALA were tentatively identified by LC-QTOF-MS, although only one was stable in the UV/free chlorine media. As regards volatile DBPs, the formation of chloroform, dichloroacetonitrile, di- and trichloroacetic acid was noticed. The mass yield of DBPs formation from VALA varied from 0.3% (dichloroacetonitrile) to 1.1% (chloroform). The efficiency of UV/free chlorine was first investigated in spiked solutions with increasing complexities: ultrapure, river and treated wastewater. Thereafter, the feasibility of reducing VALA levels in polluted river water was demonstrated.

Multiresidue procedure to assess the occurrence and dissipation of fungicides and insecticides in vineyard soils from Northwest Spain.

The presence of fungicide and insecticide residues in wine has been largely investigated. However, few studies have addressed the persistence of these compounds in vineyard soils. In this research, we investigate the residues of a relevant number of fungicides and insecticides in vineyard soils, obtained in the Northwest of Spain, at the beginning of each agriculture campaign. Moreover, the dissipation of species showing high concentrations were monitored during the non-vegetative period of vines, in order to understand their soil evolution between application campaigns. To this end, a multiresidue analytical procedure based on pressurized liquid extraction (PLE) followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) determination was first optimized. Under final working conditions, absolute recoveries in the range from 70 to 130% were achieved for 44 out of 51 selected compounds. The method LOQs remained at the low ng g-1 level (0.2-13 ng g-1) with a linear response range up to 500 ng g-1. Analysis of vineyard soils, collected during a 2-year period, from a geographic area with a high incidence of fungal diseases, demonstrated the presence of relevant concentrations of several fungicides and the insecticide imidacloprid (IMI) in this compartment. Most compounds detected at the end of the application season remained in soil at the beginning of the next year campaign. Among them, six fungicides (dimethomorph, boscalid, myclobutanil, penconazole, pyraclostrobin and pyrimethanil) and IMI showed average dissipation efficiencies below 50%, so they pose a potential to accumulate in this kind of soils.

Residues of anilinopyrimidine fungicides and suspected metabolites in wine samples.

The coexistence of the anilinopyrimidine fungicides pyrimethanil (PYR) and cyprodinil (CYP), and suspected metabolites in wine samples was investigated by liquid chromatography (LC) with tandem mass spectrometry (MS/MS), based on triple quadrupole (QqQ) and quadrupole time-of-flight (QTOF) MS instruments. For the first time, quantitative data obtained after solid-phase extraction (SPE) of wine samples have demonstrated the systematic presence of 4-hydroxyanilino derivatives of PYR and CYP in wines containing residues of parent fungicides, at concentrations from 0.2 to 58 ng mL-1. Higher concentration ratios (hydroxylated derivative/active fungicide) were measured in red than in white wines, particularly in case of PYR. On average, the concentrations of PYR-4OH were twice those measured for PYR in red wines. A targeted search of hydroxyl derivatives in wine extracts by LC-QTOF-MS showed the existence of additional hydroxylation positions in the pyrimidine ring and/or in the alkyl substituents bond to this cycle in the structure of both anti-botrytis fungicides. Moreover, free and glycosylated forms of the hydroxylated metabolites for both fungicides coexist in wine samples. In case of CYP, it is proved that hydroxylated and glycosylated metabolites are already present in grapes before vinification.

Generation and characterization of human induced pluripotent stem cells (iPSCs) from hand osteoarthritis patient-derived fibroblasts.

Knowledge and research results about hand osteoarthritis (hOA) are limited due to the lack of samples and animal models of the disease. Here, we report the generation of two induced pluripotent stem cell (iPSC)-lines from patients with radiographic hOA. Furthermore, we wondered whether these iPSC-lines carried single nucleotide polymorphisms (SNPs) within genes that have been associated with hOA. Finally, we performed chondrogenic differentiation of the iPSCs in order to prove their usefulness as cellular models of the disease. We performed a non-integrative reprogramming of dermal fibroblasts obtained from two patients with radiographic rhizarthrosis and non-erosive hOA by introducing the transcriptional factors Oct4, Sox2, Klf4 and c-Myc using Sendai virus. After reprogramming, embryonic stem cell-like colonies emerged in culture, which fulfilled all the criteria to be considered iPSCs. Both iPSC-lines carried variants associated with hOA in the four studied genes and showed differences in their chondrogenic capacity when compared with a healthy control iPSC-line. To our knowledge this is the first time that the generation of iPSC-lines from patients with rhizarthrosis and non-erosive hOA is reported. The obtained iPSC-lines might enable us to model the disease in vitro, and to deeper study both the molecular and cellular mechanisms underlying hOA.

Portable dehumidifiers condensed water: A novel matrix for the screening of semi-volatile compounds in indoor air.

The comprehensive identification of organic species existing in indoor environments is a key issue to understand their impact in human health. This study proposes the analysis of condensed water samples, collected with portable dehumidifiers, to characterize semi-volatile compounds in the gas phase of confined areas. Water samples are concentrated by solid-phase extraction (SPE). The obtained extracts are analysed by gas chromatography (GC) time-of-flight mass spectrometry (TOF-MS), following a non-target screening data mining approach. In first term, spectra of deconvoluted compounds are compared with those in NIST low resolution library; thereafter, tentative identifications are verified using an in-house database of accurate electron ionization (EI) MS spectra. Chromatographic (retention index) and spectral data are combined for unambiguous species identification. The potential of condensed water samples to reflect changes in the composition of indoor atmospheres, the match between data obtained using different dehumidifiers, and the relative concentration efficiency of condensed water compared to that attained by active sampling of moderate air volumes are discussed. A total of 141 semi-volatile compounds were identified (98 confirmed against authentic standards) in a set of 21 samples obtained from different homes and working places. This list contains more than 40 fragrances (including several potential allergens), solvents and intermediates in the production of polymeric materials, plasticizers and flame retardants.

Evaluation of supercritical fluid chromatography accurate mass spectrometry for neonicotinoid compounds determination in wine samples.

The suitability of supercritical fluid chromatography, coupled to accurate mass spectrometry (SFC-MS), for the determination of seven commercial neonicotinoid pesticides and one transformation product in wine samples has been investigated. Thorough optimization of the different parameters (column, modifier, back-flush pressure, make up, etc.) affecting the SFC-MS selectivity and sensitivity was carried out. Under final conditions, a 2 mL volume of either red or white wine was extracted by SPE and analysed using external standard calibration achieving limits of quantification from 1 to 11 ng mL-1. Global recoveries ranged between 63 and 118%, depending on the compound and the spiked amount. When compared to UPLC performance, SFC resulted in a better separation of compounds, narrower peaks, comparable sensitivity and significantly lower matrix effects. The developed method allowed the quantification of imidacloprid in around half of the 25 commercial wine samples processed, all of them proceeding from grapes cultivated in year 2018 in the Northwest of Spain, with a maximum concentration of 33 ng mL-1. Acetamiprid was also detected in some white wine samples.

Extended short-range order determines the overall structure of liquid gallium.

Polyvalent metal melts (gallium, tin, bismuth, etc.) have microscopic structural features, which are detected by neutron and X-ray diffraction and which are absent in simple liquids. Based on neutron and X-ray diffraction data and the results of ab initio molecular dynamics simulations for liquid gallium, we examine the structure of this liquid metal at the atomistic level. Time-resolved cluster analysis allows one to reveal that the short-range structural order in liquid gallium is determined by a range of the correlation lengths. This analysis, performed on a set of independent samples corresponding to equilibrium liquid phase, discloses that there are no stable crystalline domains and molecule-like Ga2 dimers typical for crystal phases of gallium. The structure of liquid gallium can be reproduced by the simplified model of the close-packed system of soft quasi-spheres. The results can be applied to analyze the fine structure of other polyvalent liquid metals.

Generation of a human control iPS cell line (ESi080-A) from a donor with no rheumatic diseases.

Here, we report the establishment of the human iPS cell line N1-FiPS4F#7 generated from skin cells of a patient with no rheumatic diseases, thus obtaining an appropriate control iPS cell line for researchers working in the field of rheumatic diseases. The reprogramming factors Oct4, Sox2, Klf4 and c-Myc were introduced using a non-integrating reprogramming strategy involving Sendai Virus.

Mechanisms of Plant Tolerance to RNA Viruses Induced by Plant-Growth-Promoting Microorganisms.

Plant viruses are globally responsible for the significant crop losses of economically important plants. All common approaches are not able to eradicate viral infection. Many non-conventional strategies are currently used to control viral infection, but unfortunately, they are not always effective. Therefore, it is necessary to search for efficient and eco-friendly measures to prevent viral diseases. Since the genomic material of 90% higher plant viruses consists of single-stranded RNA, the best way to target the viral genome is to use ribonucleases (RNase), which can be effective against any viral disease of plants. Here, we show the importance of the search for endophytes with protease and RNase activity combined with the capacity to prime antiviral plant defense responses for their protection against viruses. This review discusses the possible mechanisms used to suppress a viral attack as well as the use of local endophytic bacteria for antiviral control in crops.