Assessment of pesticide residues and microbial contamination in raw leafy green vegetables marketed in Italy

The role of market in motivating farmers to reduce pesticide use: Evidence from vegetable farms in Shiraz

The overuse of pesticides has harmful impacts on both the environment and human health. Implementing efficient techniques is crucial to manage pesticides and reduce negative impacts effectively. In order to achieve this objective, we evaluated the harm of pesticide application in vegetable fields in Shiraz and identified the factors that impact farmers' behavior in using pesticides. The Environmental Impact Quotient (EIQ) indicator was initially utilized to evaluate the effects of pesticide residues on both human health and the environment. Afterwards, the Logit model was employed to investigate the likelihood of excessive pesticide usage among farmers. Our findings suggest that farmers may not give high importance to environmental and human health considerations when deciding on pesticide usage. Market incentives, such as the quantity and price of vegetables produced without pesticide use, play a significant role in reducing pesticide use in Shiraz vegetable farms. The results of the study can help policy makers in implementing pesticide-free agricultural practices.

The Effect of Washing, Blanching and Frozen Storage on Pesticide Residue in Spinach

Spinach (Spinacia oleracea L.) is a representative green leafy vegetable commonly consumed fresh or as a ready-to-cook frozen product, with increasing consumption because of its many health-related properties. Among leafy vegetables, spinach poses a major concern in terms of pesticide residue detection due to common phytotechnical practices. In this study, spinach leaves were treated in the open field with three commercial pesticide formulations containing propamocarb, lambda-cyhalothrin, fluopicolide and chlorantraniliprole at the highest concentration. The effects of the successive processing steps of washing, blanching, freezing and frozen storage were evaluated on the levels of the four pesticide residues and the degradation product (propamocarb n-desmethyl). The washing step caused a reduction of fluopicolide and chlorantraniliprole of -47% and -43%, respectively, while having a mild effect on lambda-cyhalothrin content (+5%). A two-minute blanching step allowed for the reduction of pesticides content ranging from -41% to -4% with respect to the washed sample. Different behaviors were depicted for longer blanching times, mainly for propamocarb, reaching -56% after 10 min of treatment. Processing factors higher than 1 were reported mainly for lambda-cyhalothrin and fluopicolide. Frozen storage led to a slight increase in the pesticide content in samples treated for 6 and 10 min. The optimal blanching treatment for spinach, submitted to freezing and frozen storage, seems to be 2 min at 80 °C.

Characterization and Genome Study of a Newly Isolated Temperate Phage Belonging to a New Genus Targeting Alicyclobacillus acidoterrestris

The spoilage of juices by Alicyclobacillus spp. remains a serious problem in industry and leads to economic losses. Compounds such as guaiacol and halophenols, which are produced by Alicyclobacillus, create undesirable flavors and odors and, thus, decrease the quality of juices. The inactivation of Alicyclobacillus spp. constitutes a challenge because it is resistant to environmental factors, such as high temperatures, and active acidity. However, the use of bacteriophages seems to be a promising approach. In this study, we aimed to isolate and comprehensively characterize a novel bacteriophage targeting Alicyclobacillus spp. The Alicyclobacillus phage strain KKP 3916 was isolated from orchard soil against the Alicyclobacillus acidoterrestris strain KKP 3133. The bacterial host's range and the effect of phage addition at different rates of multiplicity of infections (MOIs) on the host's growth kinetics were determined using a Bioscreen C Pro growth analyzer. The Alicyclobacillus phage strain KKP 3916, retained its activity in a wide range of temperatures (from 4 °C to 30 °C) and active acidity values (pH from 3 to 11). At 70 °C, the activity of the phage decreased by 99.9%. In turn, at 80 °C, no activity against the bacterial host was observed. Thirty minutes of exposure to UV reduced the activity of the phages by almost 99.99%. Based on transmission-electron microscopy (TEM) and whole-genome sequencing (WGS) analyses, the Alicyclobacillus phage strain KKP 3916 was classified as a tailed bacteriophage. The genomic sequencing revealed that the newly isolated phage had linear double-stranded DNA (dsDNA) with sizes of 120 bp and 131 bp and 40.3% G+C content. Of the 204 predicted proteins, 134 were of unknown function, while the remainder were annotated as structural, replication, and lysis proteins. No genes associated with antibiotic resistance were found in the genome of the newly isolated phage. However, several regions, including four associated with integration into the bacterial host genome and excisionase, were identified, which indicates the temperate (lysogenic) life cycle of the bacteriophage. Due to the risk of its potential involvement in horizontal gene transfer, this phage is not an appropriate candidate for further research on its use in food biocontrol. To the best of our knowledge, this is the first article on the isolation and whole-genome analysis of the Alicyclobacillus-specific phage.

Food risk associated with vegetable consumption, exposure to antimicrobial-resistant strains and pesticide residues

This preliminary study aimed to detect biological and chemical contaminants in vegetables sold in Sicily for human consumption, assess the spread of antimicrobial-resistant (AMR) strains in these foods, and characterize their antimicrobial-resistance genes. A total of 29 fresh and ready-to-eat samples were analyzed. Microbiological analyses were performed for the detection of Salmonella spp. and the enumeration of Enterococci, Enterobacteriaceae, and Escherichia coli. Antimicrobial resistance was assessed by the Kirby-Bauer method, according to the Clinical and Laboratory Standards Institute guidelines. Pesticides were detected by high-performance liquid chromatography and gas chromatography coupled with mass spectrometry. No samples were contaminated by Salmonella spp., E. coli was detected in 1 sample of fresh lettuce at a low bacterial count (2 log cfu/g). 17.24% of vegetables were contaminated by Enterococci and 65.5% by Enterobacteriaceae (bacterial counts between 1.56 log cfu/g and 5.93 log cfu/g and between 1.6 log cfu/g and 5.48 log cfu/g respectively). From 86.2% of vegetables, 53 AMR strains were isolated, and 10/53 isolates were multidrug resistant. Molecular analysis showed that the blaTEM gene was detected in 12/38 β-lactam-resistant/intermediate-resistant isolates. Genes conferring tetracycline resistance (tetA, tetB, tetC, tetD, tetW) were detected in 7/10 isolates. The qnrS gene was detected in 1/5 quinolone-resistant isolates, the sulI gene was detected in 1/4 sulfonamide- resistant/intermediate-resistant isolates and the sulIII gene was never detected. Pesticides were detected in 27.3% of samples, all of which were leafy vegetables. Despite the satisfactory hygienic status of samples, the high percentage of AMR bacteria detected stresses the need for an effective monitoring of these foods as well as adequate strategies to counteract the spread of AMR bacteria along the agricultural chain. Also, the chemical contamination of vegetables should not be underestimated, especially considering that leafy vegetables are commonly consumed raw and that no official guidelines about maximum residue limits of pesticides in ready-to-eat vegetables are available.

Heavy metal, microbial and pesticides residue contaminations are limiting the potential consumption of green leafy vegetables in Ghana: An overview

Green leafy vegetables (such as cocoyam (Colocasia spp) leaves, spinach (Spinach spp), amaranths (Amaranthus spp), roselle leaves (Hibiscus spp), and lettuce (Lactuca spp)) form a major part of Ghanaian meals providing essential vitamin such as A, B and C and minerals including iron and calcium as well as essential bioactive compounds. However, the practices involved in the production, distribution and handling of these nutrient rich vegetables, by most value chain actors in Ghana, unfortunately pre-dispose them to contamination with pathogens, heavy metals and pesticides residues. These have therefore raised public health concerns regarding the safety and quality of these green leafy vegetables. Understanding the current perspectives of the type of pathogens, heavy metals and pesticide contaminants that are found in leafy vegetables and their health impacts on consumers will go a long way in helping to identify appropriate mitigation measures that could be used to improve the practices involved and thereby help safeguard human health. This review examined reported cases of microbial, heavy metal and pesticides residue contamination of green leafy vegetables in Ghana from 2005 to 2022. Notable pathogenic microorganisms were Ascaris eggs and larvae, faecal coliform, Salmonella spp., Staphylococcus aureus Streptococci, Clostridium perfringes, and Escherichia coli. In addition, Lead (Pb), Cadmium (Cr), Chromium (Cr), Zinc (Zn), Iron (Fe), Copper (Cu) and Manganese (Mn) have been detected in green leafy vegetables over the years in most Ghanaian cities. Pesticides residues from organochlorine, organophosphorus and synthetic pyrethroid have also been reported. Overall, microbial, heavy metals and pesticide residue contamination of Ghanaian green leafy vegetables on the farms and markets were significant. Hence, mitigation measures to curb the contamination of these vegetables, through the food chain, is urgently required to safeguard public health.

Quantification of 363 Pesticides in Leafy Vegetables (Dill, Rocket and Parsley) in the Turkey Market by Using QuEChERS with LC-MS/MS and GC-MS/MS

Contamination of agricultural products with pesticide residues is a growing concern due to their adverse health effects and increasing worldwide usage of pesticides. In 2021 a total of 200 samples of green leafy vegetables, including 80 dill, 80 rocket and 40 parsley, purchased from greengrocer shops, markets and bazaars in Corum Province, Turkey, were monitored for pesticide residues. In green leafy vegetables, 363 pesticides were analyzed using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation, followed by liquid chromatography coupled to mass spectrometry (LC-MS/MS) for 311 residues and gas chromatography coupled to mass spectrometry (GC-MS/MS) for 52 residues. The method was in-house validated at two fortification levels, and satisfactory recoveries and precisions were achieved for all residues. No quantifiable residues were found in 35% of the samples, whereas 43 residues belonging to 24 different chemical classes were detected in 130 green leafy vegetables. Among the green leafy vegetables, the highest occurrence frequency was recorded in the rocket, followed by dill and parsley. In 46% of the green leafy vegetables, the residue levels exceeded European Union Maximum Residue Levels (EU MRLs). The most frequently detected pesticides were pendimethalin (22.5%), diuron (38.7%) and pymetrozine (52.5%) in dill, rocket and parsley, respectively.

Residual characteristics and potential integrated risk assessment of synthetic pyrethroids in leafy vegetables from Zhejiang in China - Based on a 3-year investigation

Leafy vegetables have high nutritional value and are very popular in China. However, the long-term variation in residues and integrated risks of synthetic pyrethroids (SPs) in these vegetables have not been well examined. In this study, a total of 1005 samples were collected from 55 markets during 2017-2019. The cumulative exposure to nine kinds of SPs in Zhejiang, China, through the consumption of nine leafy vegetables was analyzed, and the potential integrated risk was assessed by the relative potency factor. A total of 191 samples were detected with SPs residues. The most frequently detected SPs were λ-cyhalothrin and cypermethrin. The integrated risk assessment results revealed that the dietary risk for these SPs via leafy vegetable exposure is acceptable for children, adults and elderly individuals. The data provided here will be helpful for the government to formulate food policies in China.

Chemical Contamination Pathways and the Food Safety Implications along the Various Stages of Food Production: A Review

Historically, chemicals exceeding maximum allowable exposure levels have been disastrous to underdeveloped countries. The global food industry is primarily affected by toxic chemical substances because of natural and anthropogenic factors. Food safety is therefore threatened due to contamination by chemicals throughout the various stages of food production. Persistent Organic Pollutants (POPs) in the form of pesticides and other chemical substances such as Polychlorinated Biphenyls (PCBs) have a widely documented negative impact due to their long-lasting effect on the environment. This present review focuses on the chemical contamination pathways along the various stages of food production until the food reaches the consumer. The contamination of food can stem from various sources such as the agricultural sector and pollution from industrialized regions through the air, water, and soil. Therefore, it is imperative to control the application of chemicals during food packaging, the application of pesticides, and antibiotics in the food industry to prevent undesired residues on foodstuffs. Ultimately, the protection of consumers from food-related chemical toxicity depends on stringent efforts from regulatory authorities both in developed and underdeveloped nations.

Dynamics of the Degradation of Acetyl-CoA Carboxylase Herbicides in Vegetables

(1) Background: Aryloxyphenoxy-propionates and cyclohexanediones are herbicides most widely used in dicot crops worldwide. The main objective of the study was to determine the dynamics of herbicide residues in carrot, lettuce, cauliflower, and onion in order to suggest a low level of residues in harvested vegetables. (2) Methods: Small plot field trials were carried out in four vegetables in the Czech Republic. The samples of vegetables were collected continuously during the growing season. Multiresidue methods for the determination of herbicide residues by LC-MS/MS were used. Non-linear models of degradation of individual herbicides in vegetables were calculated using the exponential decay formula. Action GAP pre-harvest intervals for the 25% and 50% maximum residue limit (MRL) and 10 µg kg⁻¹ limit (baby food) were established for all tested herbicides. (3) Results: The degradation dynamics of fluazifop in carrot, onion, and cauliflower was significantly slower compared to quizalofop and haloxyfop. The highest amount (2796 µg kg⁻¹) of fluazifop residues was detected in cauliflower 11 days after application. No residue of propaquizafop and cycloxydim was detected in any vegetable samples. (4) Conclusions: Aryloxyphenoxy-propionate herbicide (except propaquizafop) could contaminate vegetables easily, especially vegetables with a short growing season. Vegetables treated with fluazifop are not suitable for baby food. Lettuce and cauliflower treated by quizalofop are not suitable for baby food, but in onion and carrot, quizalofop could be used. Propaquizafop and cycloxydim are prospective herbicides for non-residual (baby food) vegetable production.

Non-thermal technologies: Solution for hazardous pesticides reduction in fruits and vegetables

Pesticide residues in the food above the maximum permissible residual limit (MRL) for safe consumption are a severe concern today. Though unit operations employed in domestic and industrial-scale processing of foods such as high-temperature decontamination and chemical washings degrade the agrochemicals and reduce toxicity, eliminating pesticides from the fresh and raw fruits and vegetables with the retainment of nutritional and organoleptic attributes demand appropriate non-thermal technologies. In this review, the potential of novel technologies like the pulsed electric field, high-pressure processing, irradiation, ozone, ultrasonication, and cold plasma for the reduction of pesticides in fruits and vegetables have been discussed in terms of their mechanism of action, playing around factors, advantages, and limitations. All the reviewed non-thermal technologies exhibited promising effects on pesticide degradation with their unique mechanism of action. Also, these techniques' potential to reduce the pesticides below MRLs and yield nontoxic metabolites in fruits and vegetables were analyzed. However, investigating the impact of the technologies on the nutritional and organoleptic quality profile of the commodities at the processing conditions causing noticeable pesticide reduction and the pathways of degradation reactions of various pesticides with each emerging technology should be studied to enhance the applicability.

Evaluation of Chemical and Microbiological Contaminants in Fresh Fruits and Vegetables from Peasant Markets in Cundinamarca, Colombia

ABSTRACT

In this study, chemical and microbiological contaminants were detected in fresh fruits and vegetables in peasant markets in the Department of Cundinamarca to assess food safety. At least one pesticide was detected in 63% of the samples evaluated (n = 100, including fruits and vegetables), and in 41% of these, pesticides exceeded the maximum residue limit. Within the pesticides found, 60% do not use a registry from the Instituto Colombiano Agropecuario to be applied on the crops where they were detected and are included in the toxicological categories "highly toxic" (category IB) and "moderately toxic" (category II). Heavy metals were found in 45% of the samples, with cadmium (38%) and lead (14%) being the most frequent. The pathogenic microorganisms Escherichia coli O157:H7, Listeria monocytogenes, Salmonella, and Campylobacter sp. were detected in 4, 2, 1, and 0% of the samples, respectively. Factors concerning integrated crop management, contaminated inputs with chemicals and microorganisms, and the lack of hygiene in the postharvest stage favor the presence of pesticide residues, heavy metals, and the appearance of pathogenic microorganisms. The results suggest the need to strengthen the implementation of integrated management strategies that guarantee the safety of fresh fruits and vegetables in the country.

HIGHLIGHTS

Co-exposure risks of pesticides residues and bacterial contamination in fresh fruits and vegetables under smallholder horticultural production systems in Tanzania

This study was carried out to investigate the risks of simultaneous exposure to pesticide residues and bacteria contaminants in locally produced fresh vegetables and vegetables in Tanzania. A total of 613 samples were analyzed for pesticide residues, out of which 250 were also analyzed for bacterial contamination. Overall, 47.5% had pesticide residues, 74.2% exceeded Maximum Residue Levels (MRLs). Organophosphorus (95.2%), organochlorines (24.0%), pyrethroids (17.3%), and carbamates (9.2%) residues dominated. MRL values were mostly exceeded in tomatoes, onions, watermelons, cucumbers, Chinese cabbage, and sweet paper. Tetramethrin (0.0329-1.3733 mg/kg), pirimiphos-methyl (0.0003-1.4093 mg/kg), permethrin (0.0009-2.4537 mg/kg), endosulfan (beta) (0.0008-2.3416 mg/kg), carbaryl (0.0215-1.5068 mg/kg), profenofos (0.0176-2.1377 mg/kg), chlorpyrifos (0.0004-1.2549 mg/kg) and dieldrin (0.0011-0.5271 mg/kg) exceeded MRLs. The prevalence of bacteria contamination was high (63.2%). Enterobacter (55.6%) Pseudomonas aeruginosa (32.4%), E. coli (28.2%), Citrobacter (26.8%), Klebsiella oxytoca (14.8%), and Salmonella (7.7%) were isolated. Furthermore, 46.4% tested positive for both pesticide residues and bacterial contaminants. Vegetables from farms (60.7%) contained more dual contaminants than market-based vegetables (41.8%). This may have resulted from excessive pesticide use and unhygienic handling of fresh fruits and vegetables at production level. Binary logistic regression showed that fresh fruits and vegetables with pesticide residues were 2.231 times more likely to have bacteria contaminants (OR: 2.231; 95% CI: 0.501, 8.802). The contamination levels of pesticide residues and bacterial contaminants could be perceived as a serious problem as most fresh fruits and vegetables recorded values of pesticide residues far above the MRLs with pathogenic bacteria isolated in higher proportions. MRLs was higher in most vegetables consumed raw or semi-cooked such as watermelons, carrots, cucumber, tomatoes, onion and sweet paper. There is an urgent need to develop pesticide monitoring and surveillance systems at farmer level, educating farmers and promoting the use of greener pesticides to mitigate the health effects of pesticides and bacterial contaminants.

Synthetic fresh-cut wastewater disinfection and decontamination by ozonation at pilot scale

In this research, the capability of ozonation and peroxone treatment for the simultaneous disinfection and decontamination of wash water from the fresh-cut industry has been investigated at pilot plant scale (10 L). The removal efficiency of six organic microcontaminants (OMCs) (four of them priority substances) and the inactivation of two foodborne pathogens (Escherichia coli O157:H7 and Salmonella enteritidis) in synthetic fresh-cut wastewater (SFCWW) has been assessed. Ozonation and peroxone (O₃ with 20 mgL^-1 of H₂O₂) process has been investigated under several operational conditions: natural SFCWW pH (6.25) and basic pH (11), and two different initial ozone production (0.09 and 0.15 gO₃ L^-1 h^-1). Results showed that the highest efficiency for OMCs removal (85%) and pathogen inactivation (>5-Log) were obtained with ozonation treatment at natural pH. OMCs degradation was obtained after 120 min of treatment with an ozone dose of 27.4 mgO₃ L^-1. First order kinetic constant of each OMC degradation was obtained, and two clear different groups have been identify based on their degradation profiles, which have been correlated with their chemical structure. G₁-OMC [terbutryn > buprofezin > azoxystrobin] > G₂-OMC [imidacloprid > simazine > thiamethoxam]. As for bacterial inactivation, up to 10 min of treatment time and an ozone dose of <8.6 mgO₃ L^-1 were required to reach the detection limit (2 CFU mL^-1), showing E. coli O157:H7 a higher susceptibility to be inactivated (k: 2.79 min^-1) than S. enteritidis (k: 1.47 min^-1). Moreover, from the techno-economical and toxicological assessment of the treated water with the best operational condition, can be highlighted: i) a slight acute toxicity for V. fischeri (47 ± 2.3% of luminescence inhibition), ii) an acute toxicity for Daphnia magna (100% of immobilization) and iii) a total cost of the treatment of 1.16 € m^-3.

Effects of the cooking modes on commonly used pesticides residue in vegetables and their chronic dietary exposure risk in South China

Effects of cooking modes on the real intake and chronic exposure risk of pesticide residues in vegetables are usually neglected and largely unknown. Four modes of daily meal preparation; chafing dish, soup, salad and stir-frying were studied in this work to clarify their impact on the residual pesticides in foods. A detection method for 14 types of pesticide residues in different cuisines was developed. In this work, chronic exposure risks of four pesticides were analysed by probabilistic assessment based on data from public health and a pesticide residues investigation conducted. The results showed that chafing dish and soup methods greatly lowered the types, contents and exposure risks from residue pesticides. Salad preserved almost all the pesticide residues, and the risks were also relatively high in the stir-frying method. In chafing dish and soup, pesticide residues were dispersed in the media and posed quite low threats to humans. Considering the age, infants and children were at a higher risk of exposure than other populations. Reassuringly, all of the risks were at acceptable levels. This study clarified how the cooking modes affect chronic exposure risks to pesticide residues in the vegetables. The outcomes also show the effects of cooking method on healthy daily diets.

Occurrence and level of emerging organic contaminant in fish and mollusk from Klang River estuary, Malaysia and assessment on human health risk

The occurrence, level, and distribution of multiclass emerging organic contaminants (EOCs) in fish and mollusks from the Klang River estuary were examined. The targeted EOCs for this assessment were phenolic endocrine disrupting compounds (bisphenol A, 4-OP, and 4-NP), organophosphorous pesticides (quinalphos, chlorpyrifos, and diazinon), estrogenic hormones (E2, E1, and EE2), and pharmaceutically active chemicals (primidone, sulfamethoxazole, dexamethasone, diclofenac, amoxicillin, progesterone, and testosterone). Results from this study showed that the prevalent contamination of the Klang River estuary by EOCs with diclofenac, bisphenol A, progesterone, and amoxicillin were predominantly detected in fish and mollusks. Among the EOCs, diclofenac and progesterone had the highest concentrations in fish and mollusk samples, respectively. The concentrations of diclofenac and progesterone in fish and mollusk samples range from 1.42 ng/g to 10.76 ng/g and from 0.73 ng/g to 9.57 ng/g, respectively. Bisphenol A should also be highlighted because of its significant presence in both fish and mollusks. The concentration of bisphenol A in both matrices range from 0.92 ng/g to 5.79 ng/g. The calculated hazard quotient (HQ) for diclofenac, bisphenol A, and progesterone without consideration to their degradation byproduct were less than one, thus suggesting that the consumption of fish and mollusks from the Klang River estuary will unlikely pose any health risk to consumers on the basis of the current assessment. Nonetheless, this preliminary result is an important finding for pollution studies in Malaysian tropical coastal ecosystems, particularly for organic micropollutant EOCs, and can serve as a baseline database for future reference.

A multifaceted approach to harness probiotics as antagonists on plant based foods, for enhanced benefits to be reaped at a global level

Investigations into probiotics have focused on their health benefits thus far, with some of the findings finally reaching the food and pharmaceutical industries, which have used them for commercial purposes. In biocontrol research some microbes, mainly isolated from plants, have shown antagonism towards both enteric and plant pathogens, and some of them represent probiotic species. Fresh fruits and vegetables are regarded as health-promoting dietary constituents, and if probiotics could be used to control the pathogens on them then they could turn out to be even healthier. The fresh produce industry still depends on agrochemicals and the increase in the demand for high-priced organically grown produce indicates consumer concerns regarding the use of agrochemicals. If the potential of probiotic organisms to serve as biocontrol agents for fresh produce is exploited, all fresh produce can be made as safe as organically grown produce, and much more wholesome. This review appraises the feasibility of such a move by evaluating how research has progressed in both disciplines (probiotic and biocontrol) and suggests sharing results from research via information technology, efficient collaboration, and the use of novel molecular biological tools to achieve the objective of probiotic antagonists. © 2018 Society of Chemical Industry.

Key characteristics of foods with an elevated risk for viral enteropathogen contamination

Viral enteropathogens are one of the leading causative agents of foodborne illnesses in both the United States and the European Union. While human noroviruses and hepatitis A virus cause the vast majority of outbreaks and illnesses, there are handful of human enteric viruses that contribute to sporadic outbreaks worldwide including astrovirus, sapovirus, rotavirus, enterovirus and Aichi virus. In addition, hepatitis E virus is increasingly being recognized as an emerging zoonotic threat within the food supply. This review aims to briefly describe the primary human enteric viruses of concern with respect to foodborne transmission. Next, we focus on the contamination and persistence of these viruses within three high-risk food commodities-leafy greens, soft red fruits and bivalve mollusks. As opposed to detailing the specific routes by which these foods can be contaminated with enteric viruses, we have chosen to focus on their persistence and specific interactions within the food itself. Therefore, the processes of attachment and internalization of the viruses in foods have been emphasized. Looking forward, the implications of these specific interactions of human enteric viruses with leafy greens, soft red fruits and bivalve mollusks are briefly considered within the context of future prevention and control strategies.

Hepatitis E virus in lettuce and water samples: A method-comparison study

The hepatitis E virus (HEV), which is an increasing cause of acute viral hepatitis in Europe, is a zoonotic virus that is mainly transmitted through contaminated water, consumption of raw or undercooked meat from pigs or wild boar, blood transfusion, and organ transplantation. Although the role of HEV transmission through contaminated produce has not been confirmed, the presence of HEV has been reported in irrigation waters and in vegetables. The present study used a World Health Organization (WHO) international standard and clinical samples to evaluate the performance characteristics of three RT-qPCR assays for detection and quantification of HEV. Two of the evaluated assays provided good analytical sensitivity, as 250 international units (IU) per ml could be detected. Then, experiments focused on evaluating the elution conditions suitable for HEV release from vegetables, with the method proposed by the ISO 15216:2017 selected for evaluation in three types of fresh vegetables. The concentration method proposed by the ISO 15216:2017 combined with the RT-qPCR described by Schlosser et al. (2014) resulted in average HEV recoveries of 1.29%, 0.46%, and 3.95% in lettuce, spinach, and pepper, respectively, with an average detection limit of 1.47 × 105 IU/25 g. In naturally contaminated samples, HEV was detected in sewage only (10/14), while no detection was reported in lettuce (0/36) or in irrigation water samples (0/24).