Systematic Review and Meta-analysis: Salmonella spp. prevalence in vegetables and fruits

In this study, a systematic review and a meta-analysis were conducted to analyse recent worldwide information about the prevalence of Salmonella spp. in vegetables and fruits to estimate the effect of the different processes such as washing, cutting or disinfection, and place of sampling. A systematic search was conducted for articles from 2014 to 2020 published to date regarding prevalence of Salmonella spp. in vegetables and fruits, without excluding material by location, or author. It was possible to determine eight categories for vegetables and fruits in comparison with the meta-analysis which showed five categories due to data availability. Results showed prevalence for Salmonella spp. of 0.1%, 0.2%, 13.7%, 0.1%, and 0% for fruits, leafy vegetables, mixed vegetables related to ready-to-eat salads (RTE), tubercles, and tomatoes, respectively. Moreover, categories such as fruits, tubercles, and tomatoes as associated with different types of preparations and places of sampling (Retail stores, fresh products wholesale, street markets, distribution centers, farms, and processing plants) did not present a significant combined effect on the prevalence of Salmonella spp. Likewise, leafy, and mixed vegetables showed differences associated with a type of processing, where leafy fresh unprocessed vegetables had a significant positive effect on the prevalence of the pathogen regarding the RTE products. These findings may be useful for the construction of a quantitative model of risk assessment as a means to characterize the differences among the sort of vegetable, fruit, type of processing, and place of sampling.

Effect of a Transtheoretical Model-based intervention on fruit and vegetable intake according to perception of intake adequacy: A randomized controlled community trial

Interventions based on the Transtheoretical Model (TTM) are usually effective at increasing fruit and vegetable (FV) intake, but it is not known whether individuals with misperceived intake [e.g., in pseudomaintenance (PM)] for FV intake also benefit from these interventions. This study aims to describe the effectiveness of a TTM-based intervention for FV intake according to baseline perception of intake adequacy. A randomized controlled community trial was carried out with 3414 users of a health promotion service in Belo Horizonte, Brazil, aged 20 years or over, in 2013-2014. FV intake was estimated using a validated instrument. PM was identified when participants had insufficient FV intake and thought their intake was adequate. The intervention group (IG) received a TTM-based intervention, and the control group (CG) received usual care. Baseline FV intakes were lower among individuals in PM compared to those with a concordant perception (CP). In both the IG and CG, FV intake increased among those in PM. Fruit intake remained stable, and vegetable intake decreased among those with CP. Generalized estimating equations revealed a significant effect of the intervention on fruit intake at follow-up, which was slightly higher among those in PM. We conclude that participants in PM were partially sensitive to the intervention and improved fruit intake at follow-up. We suggest that future studies emphasize vegetable intake and elucidate how TTM pillars (self-efficacy, decisional balance, processes of change) can be best used to increase FV intake.

Cucurbit[7]uril as a matrix solid-phase dispersion for the extraction of quaternary ammonium pesticides from vegetables and their determination using HPLC-UV

Cucurbit[7]uril (Q[7]) was first used as a dispersant sorbent material in a matrix solid-phase dispersion for the simultaneous extraction of four quaternary ammonium pesticides from vegetables before analysis using high-performance liquid chromatography with UV detection. Q[7] exhibited a better selectivity and adsorption capability for these compounds, which is due to its ability to bind selectively organic molecules into its hydrophobic cavity and to form stable host-guest inclusion complexes. Various parameters affecting the extraction were investigated and optimized, such as sorbent/sample mass ratio, grinding time, rinsing and eluting conditions. Under optimized conditions, the proposed method exhibited a linear response in the concentration range of 1-100 μg·kg^-1, satisfactory recoveries for eight types of vegetable samples (>70%), and high repeatability (RSD < 9.0%). The limits of quantification were between 0.43 μg·kg^-1 and 0.99 μg·kg^-1, which is nearly 50 times lower than the maximum residue limits established by the European Council.

Low field, time domain NMR in the agriculture and agrifood sectors: An overview of applications in plants, foods and biofuels

In this contribution, a selective overview of low field, time-domain NMR (TD-NMR) applications in the agriculture and agrifood sectors is presented. The first applications of commercial TD-NMR instruments were in food and agriculture domains. Many of these earlier methods have now been recognized as standard methods by several international agencies. Since 2000, several new applications have been developed, using state of the art instruments, new pulse sequences and new signal processing methods. TD-NMR is expected, in the coming years, to become even more important in quality control of fresh food and agricultural products, as well as for a wide range of food-processed products. TD-NMR systems provide excellent means to collect data relevant for use in the agricultural environment and the bioenergy industry. Data and information collected by TD-NMR systems thus may support decision makers in business and public organizations.

Anticholinesterase activity and antioxidant properties of Heinsia crinita and Pterocarpus soyauxii in Drosophila melanogaster model

Background

Plant alkaloids have become important sources of nutraceuticals owing to their pharmacological importance especially in the management of neurodegenerative diseases such as Alzheimer’s disease. In assessing the therapeutic potentials of plant phytochemicals, the fruit fly (Drosophila melanogaster) has emerged as a very veritable tool and has been largely accepted as an alternative model in biomedical research.

Objectives

In this study, alkaloid extracts from bush apple (Heinsia crinita (Afzel.) G. Taylor and padauk (Pterocarpus soyauxii Taub.) leaves were assessed on D. melanogaster exposed to aluminum toxicity.

Materials and methods

Alkaloid extracts were prepared by solvent extraction method. Thereafter, the extracts were evaluated for their in vitro antioxidant properties, Fe²⁺-chelating abilities and inhibitory effects on drosophila acetylcholinesterase (AChE) activity. The samples were also characterized for their constituent alkaloids via HPLC. Thereafter, effective safe dose of the extracts were determined in D. melanogaster (Harwich strain). Subsequently, flies assaulted with AlCl₃ were co-treated with the extracts (8.3 and 16.6 μg/g) for seven days, during which their survival rate was monitored. This was followed by assaying for the activities of AChE, antioxidant enzymes [superoxide dismutase (SOD), catalase and glutathione-S-transferase (GST)]. Also, the flies were assayed for levels of thiobarbituric acid reaction substance (TBARS) and reactive oxygen species (ROS).

Results

The results revealed that both extracts showed in vitro antioxidant properties with Padauk showing significantly higher antioxidant properties in vitro. However, there was no significant difference in their in vitro AChE inhibition. In vivo, Al-induced toxicity reduced survival rate, elevated AChE, SOD and GST activities, as well as TBARS and ROS levels which were ameliorated by the extracts. It was also revealed that piperine was predominant in PA, while 1-cyclohexen-1-yl-pyrrolidine was predominant in BA.

Conclusion

Our data suggest that the protective abilities of these extracts against Al-induced toxicity can be primarily associated with their anticholinesterase and metal chelating abilities. Thus, these vegetables can be potential sources of nutraceuticals against aluminum toxicity and associated diseases.

Retail fresh vegetables as a potential source of Salmonella infection in the Mekong Delta, Vietnam

From July 2017 to Jan 2019, a total of 572 retail fresh vegetables were collected to clarify the contamination of Salmonella in the Mekong Delta, Vietnam. Salmonella was isolated from 74 (12.9%) of 572 samples. The isolation rate of Salmonella from retail fresh vegetables in the rainy season (15.3%) was significantly higher than that in the dry season (7.6%) (P < 0.05). Of 74 Salmonella isolates, Salmonella Weltevreden was the most predominant serovar (35.1%) identified from retail fresh vegetables in all of the wet markets. All S. Weltevreden isolates (100%) were susceptible to nine antibiotics examined. Thus, retail fresh vegetables were considered as an important potential vehicle of Salmonella transmission to humans in the Mekong Delta. These results provide important data for preventing and controlling human salmonellosis in this area.

Source, transportation, bioaccumulation, distribution and food risk assessment of perfluorinated alkyl substances in vegetables: A review

Contamination of perfluoroalkyl substances (PFASs) in agricultural products have attracted more and more attentions recently. In this review, relationship between PFASs and vegetables is summarized comprehensively. PFASs could transfer to cultivation soils by irrigation water, bio-amended soil, and atmospheric deposition mainly from industrial emissions. Carbon chain length of PFASs, species of vegetables and so on are key factors for PFASs migration and bioaccumulation in soils, plants and vegetables. Studies on food risk assessment of PFOA and PFOS show low consumption risk for most vegetables, however researches on other substances are lacking. In the future, we need to pay more attention on novel pollution pathway in cultivation, traceability research for considerable contamination, dietary exposure levels for different vegetables and more substances, as well as more exact and scientific food risk assessments. Additionally, effective means for PFASs adsorption in soil and removal from soil are also expected.

First report of cucurbit chlorotic yellows virus infecting cucumber in South Korea

In October 2018, cucumber plants showing yellowing and chlorotic mottle symptoms were observed in a greenhouse in Chungbuk, South Korea. The observed symptoms were similar to those caused by cucurbit aphid-borne yellows virus (CABYV), which has been detected on cucumber plants in the region since it was reported on melon in Korea in 2015 (Lee et al 2015). To identify the potential agents causing these symptoms, 28 samples from symptomatic leaves and fruit of cucumber plants were subjected to total RNA extraction using the Plant RNA Prep Kit (Biocubesystem, Korea). Reverse transcription polymerase chain (RT-PCR) was performed on total RNA using CABYV specific primers and protocols (Kwak et al. 2018). CABYV was detected in 17 of the 28 samples, while 11 symptomatic samples tested negative. In order to identify the cause of the symptoms, RT-PCR was performed using cucurbit chlorotic yellows virus (CCYV) and cucurbit yellow stunting disorder virus (CYSDV) specific primers (Wintermantel et al. 2019). Eight of the 28 samples were positive using the CCYV specific primers while seven samples were infected with only CCYV and one contained a mixed infection of CABYV with CCYV. None of the samples tested positive for CYSDV. The expected 373 nt amplicons of CCYV were bi-directionally sequenced, and BLASTn analysis showed that the nucleotide sequences shared 98 to 100% identity with CCYV isolates from East Asia, including NC0180174 from Japan. Two pairs of primers for amplification of the complete coat protein and RNA-dependent RNA polymerase (RdRp) genes (Wintermantel et al., 2019) were used to amplify the 753bp coat protein and 1517bp RdRp genes, respectively. Amplicons of the expected sizes were obtained from a CCYV single infection and ligated into the pGEM T- Easy vector (Promega, WI, USA). Three clones from each amplicon were sequenced and aligned using Geneious Prime and found to have identical sequences (Genbank accession nos. MW033300, MW033301). The CP and RdRp sequences demonstrated 99% nucleotide and 100% amino acid identity with the respective genes and proteins of the CCYV isolates from Japan. This study documents the first report of CCYV in Korea. Since CCYV was first detected on melon in Japan, it has been reported in many other countries including those in East Asia, the Middle East, Southern Europe, North Africa, and recently in North America. CCYV has the potential to become a serious threat to production of cucurbit crops in Korea, particularly due to the increasing prevalence of the whitefly, Bemisia tabaci, in greenhouse production systems. It will be important to continue monitoring for CCYV and determine potential alternate hosts in the region to manage and prevent further spread of CCYV in Korea.

Occurrences of eight common-used pesticide adjuvants in ten vegetable species and implications for dietary intake in North China

Pesticide adjuvants (PAs) are important components of pesticide products. However, limited information is available regarding their occurrences in foodstuffs. Herein, eight common-used PAs were investigated in vegetables in North China in 2014-2016. The residue levels of total PAs in vegetables from markets and farms were 500 and 661 μg/kg, respectively. The highest residues of total PAs were found in cauliflowers (average: 1.53 × 10³ μg/kg, market vegetables) and spinaches (average: 3.72 × 10³ μg/kg, farm vegetables), respectively. In addition, Tristyrylphenol ethoxylates (TPE) dominated the total 8 PAs concentrations in most vegetable species. Moreover, the risk assessment showed that the human health risks associated with TPE and nonylphenol (NP) exposure via vegetables for adults were acceptable, and the estimated daily intakes (EDIs) of other six PAs were in the range of <0.010-0.89 μg/kg bw/day, which were less likely to pose a threat to human health.

Wide-scope screening for pharmaceutically active substances in a leafy vegetable cultivated under biogas slurry irrigation

The use of livestock waste for the production of biogas and the application of biogas slurry to agricultural soil can resolve livestock waste problems and reduce synthetic fertiliser use. However, the migration of veterinary drugs to land and crops resulting from biogas slurry irrigation is a potential food safety concern. This study employed an ultra-performance liquid chromatography coupled with quadrupole-time of flight high-resolution mass spectrometry system for wide-scope suspect screening of pharmaceutically active substances on crop cultivated under biogas slurry irrigation. Briefly, a total of 22 pak choi samples were obtained from a greenhouse farmed in tropical south Taiwan between March 2019 and March 2020. Molecular spectra and fragmented ions (between m/z 70 and 1100) were acquired. Ion features were searched and matched with a library consisting of 1068 compounds. The matrixes in the crop production environment including soil, livestock wastewater, biogas slurry, and groundwater were included in this study to elucidate potential sources of the pharmaceutically active substances. Results demonstrated 23 suspects were matched with high mass accuracy (mass error within ±5.0 ppm) in pak choi. The detection of both bufexamac and nandrolone were confirmed using standards, where a new system of identification points was applied. Nandrolone was detected throughout the pak choi samples as well as livestock wastewater. Tetracycline, macrolide, and sulfonamide antibiotics were presented in biogas slurry and soil but not pak choi. This is the first study to reveal the presence of multiclass pharmaceutically active substances in a crop supplied as food. Such findings suggest that anabolics and antibiotics should be closely monitored in the corps irrigated by biogas slurry in future.

Uptake of cephalexin by lettuce, celery, and radish from water

The introduction of pharmaceuticals into agricultural lands from the application of biosolids and animal manure, and irrigation with treated wastewater has led to concern for animal and human health after the ingestion of pharmaceutical-tainted agricultural products. In this study, the uptake and accumulation of cephalexin, a commonly prescribed antibiotic, was compared in three common vegetables (lettuce, celery, and radish) grown in nutrient solution for 144 h. During the uptake experiments, cephalexin concentration in the nutrient solution decreased in the order of radish > celery > lettuce, while the accumulation of cephalexin in vegetable roots followed the rank of lettuce > celery > radish. The accumulation of cephalexin was below the limit of detection in radish roots. No accumulation of cephalexin was observed in the shoots of all three vegetables. The behaviors of cephalexin in vivo were further elucidated using in vitro measurements of cephalexin sorption by vegetable roots and transformation in plant enzyme extracts. The affinity of cephalexin to lettuce > celery > radish roots, and the respective sorption coefficients of 687, 303, and 161 mL g-1, coupled to the transformation of cephalexin in root enzyme extracts with estimated reaction rate constants of 0.020, 0.027 and 0.024 hr-1 for lettuce, celery and radish, could help elucidate the accumulation observed in the in vivo experiments. Overall, sorption by plant roots (affinity) and reaction with plant enzymes could collectively influence the uptake and accumulation of cephalexin in vegetables.

Chemo-Preventive Effect of Vegetables and Fruits Consumption on the COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) is a new disease caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is a global pandemic that has claimed the death of 1,536,957 human beings worldwide including 287,842 deaths in the United States as of December 3, 2020. It has become a major threat to the medical community and the entire healthcare system in every part of the world. Recently, the Food and Drug Administration (FDA) has approved the emergency use of Pfizer and Moderna COVID-19 vaccine on December 12, 2020. However, there are concern about the new COVID-19 vaccine safety, efficacy, and immunity after the vaccination. In addition, both coronavirus and COVID-19 vaccine are new at this point and there is no scientific evidence to know whether people who are vaccinated can still carry the COVID 19 pathogens and pass them along to others. Therefore, many people all over the world have an increased interest in consuming more VF for the purpose of maintaining their health and boosting their immune system. Identifying novel antiviral agents for COVID-19 is of critical importance, and VF is an excellent source for drug discovery and therapeutic development. The objective of this study is to test the hypothesis that a high intake of vegetables and/or fruits prevents COVID-19 incidence and reduces the mortality rate. To achieve this objective, we collected the diet data of COVID-19 from Kaggle (https://www.kaggle.com/mariaren/covid19-healthy-diet-dataset), and used a machine-learning algorithm to examine the effects of different food types on COVID-19 incidences and deaths. Specifically, we used the feature selection method to identify the factors (e.g., diet-related factors) that contribute to COVID-19 morbidity and mortality. Data generated from the study demonstrated that VF intake can help to combat the SARS-CoV-2. Taken together, VF may be potential chemopreventive agents for COVID-19 due to their antiviral properties and their ability to boost the human body immune system.

CSA Partnerships for Health: outcome evaluation results from a subsidized community-supported agriculture program to connect safety-net clinic patients with farms to improve dietary behaviors, food security, and overall health

Safety-net clinic patients are at risk for food insecurity, which is associated with poor diet quality and negative health outcomes. Research on the impact of interventions addressing food insecurity in health care settings is limited. The primary aim of this study was to determine the preliminary effectiveness of Community-Supported Agriculture (CSA) Partnerships for Health, a 23 week grant-subsidized CSA program, in improving dietary behaviors, self-efficacy to eat vegetables, food security, and overall health among safety-net clinic patients. This single-group pretest-posttest study used interviewer-administered surveys. Study participants were 48 safety-net clinic patients. Outcomes included fruit and vegetable intake, frequency of dark green and orange vegetable intake, self-efficacy to eat vegetables, eating habits, food security status and ability to afford to eat healthy meals, emotional health, social health, and general health status. Differences in values at postintervention versus preintervention were examined using two-sided paired t-tests, McNemar's tests, and generalized estimating equation models. The difference between postintervention versus preintervention values was statistically significant for a number of outcomes, including vegetable intake (p = .030), orange vegetable intake (p = .004), eating habits (p = .039), food security (p = .039), ability to afford to eat healthy meals (p = .003), and general health status (p = .039). Generalized estimating equation models showed similar associations. CSA Partnerships for Health may have the potential to improve dietary behaviors, reduce food insecurity, and improve overall health among safety-net clinic patients.

Colon Cancer Risk of a Westernized Diet Is Reduced in Mice by Feeding Cruciferous or Apiaceous Vegetables at a Lower Dose of Carcinogen but Not a Higher Dose

Western-style diets (WD) are associated with greater risk of colon cancer. Exposure to 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), a food-borne carcinogen, is linked to increased colon cancer risk. In contrast, intake of apiaceous and cruciferous vegetables (APIs and CRUs) is associated with reduced risk. Here we evaluated effects of a WD alone or a WD containing API or CRU, relative to a purified diet (basal), on colon cancer risk in mice. All diets were fed at one of two concentrations of PhIP (100 or 400 ppm). The activity of the hepatic PhIP-activating enzyme, cytochrome P450 (CYP) 1A2, was examined at week 4 and colonic precancerous lesions (aberrant crypt foci, ACF) were enumerated at week 12. In low PhIP-fed groups, CYP1A2 activity was greater for CRU than all other groups, which did not differ from one another. WD had a significantly greater effect on the formation of ACF than the basal diet. In groups fed API or CRU, the ACF number was reduced to the level observed in the basal diet-fed group. In high PhIP-fed groups, all WD-based diets had greater CYP1A2 activity than the basal diet-fed group. Surprisingly, the basal diet group had more ACF than the WD group, and API and CRU groups did not differ from the WD alone group. Thus, at the lower dose of PhIP, the WD increased colon cancer risk in mice, compared to a purified diet, and APIs and CRUs reduced the risk of the WD. However, at the higher dose of PhIP, the enhancement of colon cancer risk by the WD was not evident, nor was the chemopreventive effect of these vegetables.

Organophosphate and carbamate pesticide residues and accompanying risks in commonly consumed vegetables in Kenya

The current study was conducted to assess the levels of organophosphates and carbamates in vegetables in Kenya and to examine potential consumer health risks. A total of 90 samples were analysed by liquid chromatography/high-resolution tandem mass spectrometry. Residues of acephate, chlorpyrifos, methamidophos, omethoate and profenofos were found in 22% of the samples, ranging from 10 to 1343 μg/kg. The EU MRL was exceeded in 21%, 10%, 8% and 22% of the samples of French beans, kales, spinach and tomatoes, respectively. Chlorpyrifos in spinach had an acute HQ of 3.3 and 2.2 for children and adults, respectively, implying that potential health risks with respect to acute dietary exposure cannot be excluded. For chronic dietary exposure, all chronic HQs were below 1. The HI for the pesticides was 0.54 and 0.34 for children and adults. Routine monitoring of OPs and carbamates in vegetables is recommended to minimise consumer's health risks.

First Report of Bacterial Leaf Spot of Cucurbita pepo Caused by Erwinia persicina in China

In February 2020, the common symptoms of water-soaked spots on Cucurbita pepo L. cotyledon were observed in Guangrao county in Shandong province, China. Field investigation showed that 40% of the Cucurbita pepo cotyledons in an area of approximately 0.8 ha were infected. The disease resulted in a severe loss in seedling production. Samples of C. pepo with water-soaked leaf spots were collected and prepared for pathogen analysis. Symptomatic cotyledon tissue was surface disinfested in 75% ethanol for 30 sec, then rinsed three times in sterilized water. Bacteria were released in sterile water in Petri dish for 2 min by cutting symptomatic tissue into small sections and stirring the plant tissue mixture fully. The diffusate was streaked onto plates containing nutrient agar (NA) and plates were incubated at 28℃ for 2 days. Three representative isolates were purified eventually from each of the plates. Colonies on NA were small, round and with smooth margins. All bacterial isolates characterized as gram-negative, white to cream color, and pink pigment was formed on the plates over long-term culture. The isolates were positive for catalase, Voges-Proskauer, potato rot, methyl red, acetoin production, nitrate utilization and citrate utilization, and acid production from maltose, glucose, melezitose, sucrose, D-arabinose, D-trehalose, cellobiose, lactose, raffinose, mannitol, D-sorbitol, melibiose and xylitol. KOH production was demonstrated according to strand formation within the potassium hydroxide test (Suslow et al. 1982). Isolates were negative for oxidase, arginine dihydrolase, phenylalanine deaminase, gelatinase, esculine, indole production and H2S production. Total genomic DNA was extracted from isolate XHL2002230201 with TIANamp Bacteria DNA Kit (TIANGEN). Universal primers 27F and 1492R (Monciardini et al. 2002) were used in PCR to amplify a 1,307-bp DNA fragment of the 16S rRNA region for molecular identification. Furthermore, four additional housekeeping genes (gyrB, atpD, rho, and rpoS) were selected and amplified using specially designed primers. The amplification products of 16S rRNA were sequenced and submitted to GenBank under accession number (MT568607.1). Sequence analysis showed 99% similarity to Erwinia persicina strains B57 (LM651373.1) and B64 (CI789_17875) by BLAST search in GenBank database (Gálvez et al. 2015; Cho et al. 2019). A phylogenetic tree was constructed, and the taxonomic position of strain XHL2002230201 was determined from the multilocus sequence analysis (MLSA) on 16S rRNA and other four housekeeping genes with E. persicina and not with other closely related Erwinia species. Pathogenicity tests and re-isolation and re-identification of the bacteria were performed to confirm the isolate and fulfill the Koch' postulates. The strain XHL2002230201 suspensions (108 CFU ml-1) were spray inoculated onto fifteen Cucurbita pepo seedlings with two true leaves, and the same number of control plants were inoculated with water. Experiments were repeated three times. All inoculated plants were kept in a moist chamber placed in a greenhouse at 28℃. Initial symptoms were observed on leaves of inoculated plants at 5 days post-inoculation, whereas no symptoms appeared on the plants inoculated with sterile distilled water. Based on morphological and biochemical characteristics, phylogenetic analysis, and Koch's postulates, the bacterial isolates were identified as E. persicina. To our knowledge, this is the first report of E. persicina causing leaf spot disease on Cucurbita pepo in China.

First report of lettuce necrotic leaf curl virus infecting cultivated lettuce in France

Lettuce necrotic leaf curl virus (LNLCV, genus Torradovirus, family Secoviridae) has a bipartite single-stranded RNA genome and has so far only been reported in the Netherlands in open field lettuce (Verbeek et al. 2014). It was the first Torradovirus described from non-tomato host and, contrary to whitefly-transmitted tomato torradoviruses, aphids are its natural vectors (Verbeek et al. 2017). In October 2019, a symptomatic lettuce (JG3, cv. "Tregoney") was collected in an open field in southwestern France. Symptoms included stunted and deformed leaves with light necrosis and yellow spotting along minor veins of older leaves. Double-stranded RNAs were purified from JG3 leaves as described (Marais et al. 2018) and a cDNA library prepared and analyzed by Illumina NovaSeq sequencing. Analysis of sequence data identified two nearly fully assembled RNAs integrating respectively 28.9% and 60.9% of the sequencing reads and sharing respectively 85.5% and 83.3% nucleotide (nt) identity with the RNAs 1 and 2 of the LNLCV reference isolate, (NC_035214 and NC_035219, respectively). To confirm the presence of LNLCV in the original JG3 plant, it was used to mechanically inoculate indicator Nicotiana benthamiana, Chenopodium quinoa and C. amaranticolor plants. Only N. benthamiana developed symptoms, in the form of smaller and yellowed leaves. All inoculated plants were tested one month post-inoculation for the presence of LNLCV. Total RNAs were extracted according to Foissac et al. (2005) and used for RT-PCR tests with primers designed from the alignment between NC_035214 and our RNA1 sequence (LNLCV-S 5'-ATATTTTCCAAGTTGGAGGCTC-3' and LNLCV-R 5'-AGTRACAAAGGGACTAACTG-3'). LNLCV was detected in 3 out of 4 inoculated N. benthamiana plants. The full length RNA1 sequence (7577 nt) and the near complete RNA2 (5286 nt, lacking 3 nt at the 5' end as compared to NC_035219) could be assembled from the JG3 sequencing data and have been deposited in GenBank (MW172270 and MW172271, respectively). The lettuce JG3 isolate RNA1 shows 86.5% nt identity with the reference isolate while the taxonomically informative protease-polymerase regions share 96.8% aa identity. JG3 RNA2 shares 84.8% nt identity with NC_035219 while the movement protein and capsid subunits share respectively 92.5% and 98.3% aa identity. The smaller upstream ORF that slightly overlaps with the large MP-CP1/2/3 ORF is also conserved and shows 94.8% aa identity with the reference isolate. To our knowledge, this represents the first report of a natural infection of LNLCV in cultivated lettuce in France and anywhere outside the Netherlands. Since no other viruses were detected in the sequence dataset, LNLCV is most likely responsible for the mild necrosis and leaf deformation symptoms observed on the JG3 plant that appear to be similar to those initially described for LNLCV (Verbeek et al. 2014). While the pathogenicity of LNLCV in lettuce appears to be firmly established, further studies are needed to establish its distribution and prevalence, to understand why this pathogenic and aphid-transmitted virus is not more widely reported and whether it has the potential to increase in impact as a potential emerging agent on field lettuce crops.

Incidence and genetic variability of Listeria monocytogenes isolated from vegetables in Poland

The aim of the present study is to investigate the prevalence and genetic diversity of Listeria monocytogenes in various fresh and frozen vegetable products available in Poland. The samples were collected at retail market within the framework of national official control and monitoring program. In the years 2016-2019 a total of 49 samples out of 8712 collected vegetable samples were positive for L. monocytogenes. Our findings demonstrated that the occurrence of L. monocytogenes in various vegetable products was generally low, on average only 0.56% in the studied years. All isolates were susceptible to 11 antimicrobial agents: penicillin, ampicillin, meropenem, erythromycin, sulfamethoxazole-trimethoprim, amoxicillin-clavulanic acid, ciprofloxacin, chloramphenicol, gentamicin, vancomycin, and tetracycline. All of them harbored virulence-associated genes (inlA, inlC, and lmo2672), 82% harbored inlJ gene and few of them (22%) also possessed the llsX gene. The majority of collected isolates (65%) belonged to molecular serogroup 1/2a-3a, followed by 4ab-4b-4d-4e (33%), and only one to serogroup 1/2b-3b-7 (2%). Isolates yielded 18 different restriction profiles, revealing a large cluster of contamination linked to frozen corn (21 strains) and distributed in 3 pulsotypes. MLST analysis classified selected isolates into nine clonal complexes (CCs). The obtained results contribute to characterizing the diversity of L. monocytogenes isolated from various vegetable products in Poland and their impact on food safety and public health.

Arbuscular mycorrhiza in combating abiotic stresses in vegetables: An eco-friendly approach

Vegetable production is hampered by several abiotic stresses which are very common in this era of climate change. There is a huge pressure on the plants to survive and yield better results even in the prevalence of various environmental stresses such as cold stress, drought, heat stress, salinity etc. This necessitates the need of robust plant growth which is possible with mycorrhizal association. Mycorrhiza improves plants tolerance to several abiotic stresses by various physiological, functional and biochemical changes in plants. The application of arbuscular mycorrhiza (AM) as vegetable biofertilizers doesn’t only influence the plant health, but moreover discursively it lowers the demand for harmful chemical fertilizers. Overall, it may be concluded that inoculation of vegetables with arbuscular mycorrhizal fungi can be used, as it easily guards plants against undesirable abiotic stresses. In this work, information is provided based on several examples from the literature based on the application of AM to combat harmful abiotic stresses in vegetable crops. This paper reviews the impacts of AM fungi on the plant parameters, its functional activities and molecular mechanisms which makes it more adaptable and underline the future prospects of using AM fungi as a biofertilizer in the stress condition.

First Report of Chaetomium globosum Causing Leaf Blight on Brassica oleracea L. in China

Cabbage (Brassica oleracea var. capitata L.) is widely cultivated in China and be of important economic value. In October 2019, all the plants of cabbage inbred line '2358' cultivated in greenhouses of the Chinese Academy of Agricultural Sciences (Beijing) were showing symptoms of leaf wilt. It usually took two weeks for the leaves to get completed wilted and the plants gradually died. It was approximately 550 plants affected, and 30 plants were collected and processed as samples. Symptomatic leaves were cut into small pieces (5×5 mm), surface sterilized with 75% ethanol for 30 s, and then sterilized with 8% NaClO for 3 mins, rinsed three times in sterile distilled water, plated on complete medium (CM: 3g Casein Enzymatic Hydrolysate + 3g Casein Acid Hydrolysate + 6g Yeast Extract+10g Sucrose + 15g Agar + 1L dH2O) and incubated at 27℃ for 6 days. Subsequently, the purified culture was obtained by tissue isolation and single-spored on CM. The colony on CM was up to about 50mm and 70mm in diameter after 4 and 7 days, respectively (Supplementary Fig. 2). At the same time, the edge of the colony gradually turned brown. Microscopic observation found that the diameter of the mycelium was about 5 µm (Supplementary Fig. 3). The conidia were transparent white and ovoid-shaped, about 0.3-0.5 µm in diameter (Supplementary Fig. 4). Fungus in liquid CM were spherical with surface hairs (Supplementary Fig. 1), which was consistent with the morphological characteristics of Chaetomium globosum. The rDNA internal transcribed spacer (ITS) of isolate ZM2019 was amplified using primers ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'- TCCTCCGCTTATTGATATGC-3') (Hong et al. 2013). The amplified product was sequenced and deposited in GenBank. The 573-bp amplicon (GenBank accession no. MN833403) showed a 100% homology to C. globosum isolate CES5 (MN173145). According to the morphological and molecular characterization, the fungus causing leaf blight on '2358' was identified as C. globosum. In order to further distinguish the pathogen species, the β-tubulin (tub2) gene region were amplified using primers T-F (5'-CCCCTGAACTACCCCACC-3') and T-R (5'-TATTTGACCCGACTGACC-3') and sequenced. Finally, we further identified this pathogen as C. globosum CBS 148.51 (Wang et al. 2016), according to the blast result of the sequence (GenBank accession no. MW252170) in National Center for Biotechnology Information (NCBI). To confirm the pathogenicity of this fungus, the leaves of 12 healthy seedlings of '2358' were inoculated by spraying 106 conidia/ml suspension and 12 seedlings inoculated with sterile water served as controls. All plants were incubated in a growth chamber maintained at 27℃. Ten days after inoculation, the leaves of all plants became wilted, which were consistent with the symptom in the natural state, while the control plants remained disease-free (Supplementary Fig. 6b and Fig. 6c). Subsequently, C. globosum was isolated from the inoculated seedlings again. The entire process from isolation to inoculation was repeated again and the same results were obtained. Re-isolation of C. globosum and inoculation of the host fulfiled Koch's postulates. C. globosum has been reported previously to occur on many horticulture plants such as Punica granatum (Guo et al. 2015) and Cannabis sativa (Chaffin et al. 2020); but no brassica species has been reported so far as susceptible to C. globosum. In this sense, this is the first report of leaf blight caused by C. globosum on cabbage in China, in greenhouse condition.

First report of rubbery rot of potato caused by Geotrichum candidum in the United States

Rubbery rot of potato caused by Geotrichum candidum Link is characterized by symptoms of damp, flaccid tubers that feel rubbery when squeezed (Humpreys-Jones 1969), similar in consistency to potato diseases such as pink rot (caused by Phytophthora erythroseptica) and Pythium leak (caused by species of Pythium). In November 2019, several symptomatic tubers of potato variety 'Ciklamen' that had been held in storage since harvest and originated from an over-head irrigated, sandy-loam production field in Bingham county, Idaho were submitted to the University of Idaho for diagnosis. Shipping-point inspection records indicated 4-9% of tubers were affected. External symptoms included irregularly shaped, randomly located sunken black-colored lesions on more severely affected rubbery-textured tubers. When cut, internal affected tissue developed a greyish appearance after several minutes. Lens-shaped cavities were apparent in two of the tubers, indicating an advanced infection. A sour-milk smell accompanied the sample. To isolate the pathogen, pieces of tuber tissue approximately 5 mm in diameter were collected from the margins of symptomatic areas and surface-sanitized in sodium hypochlorite (2%) for two minutes, rinsed twice in sterile water and plated onto tap water agar amended with penicillin G (0.2 g/liter) and streptomycin sulfate (0.8 g/liter). After three days at 21°C, colonies having distinct creamy white mycelia, a sweet, juniper-like odor, and hyaline hyphae were consistently associated with diseased tissue. Cylindrical to oval-shaped arthroconidia ranged in size from 6.6-11.0 × 3.2-5.9 μm (mean = 8.4 × 4.7, n=21), within dimensions as reported by Carmichael (1957). No other pathogens including species of Pythium and Phytophthora were recovered from the sample. Pure cultures were obtained by transferring hyphal tips to potato dextrose agar plates. Species identity was confirmed via rDNA ITS sequencing using primers ITS5/4 (White et al., 1990). DNA extraction and PCR conditions were as previously described (Woodhall et al., 2013). Resulting sequences (NCBI accession numbers MT893312 and MT893315) shared 99.4% identity with G. candidum Accession KY103453.1 on GenBank. To confirm pathogenicity, ten tubers (cv. Ciklamen) were inoculated by placing a 10mm2 plug of fully colonized PDA of G. candidum on the tuber surface, and ten tubers were mock inoculated with sterile PDA plugs. After 27 days at 21C in a dew chamber, tubers were examined for symptoms. Eight of the 10 inoculated tubers exhibited a rubbery texture and fluid leaking from tubers when cut, with two tubers also exhibiting a grey internal discoloration and the distinctive smell. Control tubers did not exhibit any symptoms. Isolations were attempted from four symptomatic tubers and G. candidum was successfully recovered from three tubers. The disease has been reported sporadically in the United Kingdom (Humphreys-Jones 1969) and Korea (Kim et al., 2011) and the pathogen occurs worldwide (Carmichael 1957). Though the fungus causes a tomato rot in the United States (US) (Pritchard and Porte, 1923; Bourret et al., 2013), and potatoes with rubbery rot originating from Australia were intercepted at a US port (Farr et al., 2020), the disease has not to our knowledge been documented on potato grown in the US. Because symptoms may be confused with pink rot and Pythium leak, it is critical for producers to obtain a correct diagnosis to facilitate appropriate management strategies.

Quality assessment and potential health risk of heavy metals in leafy and non-leafy vegetables irrigated with groundwater and municipal-waste-dominated stream in the Western Region, Ghana

Vegetables cultivated in soil irrigated with untreated groundwater and municipal-waste-dominated (MWD) stream can elevate the concentration of heavy metals (Cd, Fe, Zn, Hg, Cr, and Ni) in edible parts of the crop, affecting food safety and public health worldwide. This study assessed the quality, sources, and distribution of heavy metals in surface soils, MWD stream and groundwater, and edible tissues of leafy and non-leafy vegetables from a major urban farm in the Sekondi-Takoradi metropolis, Ghana. Human health risk due to exposure to the metals in frequently consumed vegetables were investigated. Indigenous leafy vegetables (Corchorus olitorious and Amaranthus spinosus), exotic leafy vegetables (Lactuca sativa, Brassica oleracea, and Brassica rapa), and non-leafy vegetables (Capsicum annum, Raphanus sativus, Daucus carota, and Allium cepa) were collected from the urban farm. The mean concentration of Cd, Hg, and Fe ranged from 0.008 - 0.027, 0.001-0.013, and 4.517-36.178 mg/kg fw in edible parts of non-leafy vegetables, respectively and 0.011-0.035, 0.002-0.011, and 3.617-13.695 mg/kg fw in exotic or indigenous leafy vegetables. The vegetables were less impacted with the metals if compared to similar vegetables produced from other urban farms, locally and in some countries in Africa, Asia, and Europe. Water resource on the farm were not suitable for vegetable crop irrigation since mean concentration of E. coli (200 cfu/mL), Hg (0.009 mg/L), and Cd (0.019 mg/L) in the MWD stream and 80 % of the groundwater sources exceeded the safe limits recommended by the Food and Agriculture Organization. Geo-accumulation index for each metal in soil was ≤0, however, enrichment factor indicated a high anthropic enriched soil for Cr and Ni. Principal component analysis-multiple linear regression of the metals in soil identified mixed household waste/fertilizer, fertilizer, and crustal material as main sources for the heavy metal load in soil for which geogenic sources accounted for 74.3 %. Preferentially, Cd and Hg accumulated in Amaranthus spinosus, Daucus carota, and Corchorus olitorious. The estimated daily intake of each metal in the vegetables were below local and international daily dietary intake levels. At the 95th percentile concentration of each metal, target hazard quotient and the hazard index was <1 for adult male or female who consume the vegetables. Finally, appropriate agri-horticultural practices must be enforced to mitigate Cd, Ni, Cr, and Hg accumulation in the soil-vegetable system since the metals have profound adverse effect on human health.

Investigation of parasitic contamination of salad vegetables sold by street vendors in city markets in Damascus, Syria

Monitoring parasitic contamination in raw vegetables used in salads is an important measure in controlling the occurrence of gastroenterological diseases, which may be life-threatening. This study aimed to inspect the parasitological contamination of some raw vegetables used in salads. Eight commonly consumed vegetable types were purchased from street vendors in the city markets. Vegetables were washed and the sediments were obtained for microscopic examination. Genomic DNA was isolated from contaminated samples. Our result showed that 34.4% of the studied samples were contaminated with one or more species of parasites. Lettuce was the most commonly contaminated vegetable type (29.5%), while tarragon leaves showed the lowest level of contamination (2.3%). The risk of contamination was significantly higher in lettuce samples in comparison with the other samples studied. Giardia duodenalis was the most prevalent parasite detected (38.6%) and was abundantly found in lettuce isolates (23.5%). Molecular typing revealed that all Giardia samples found in the contaminated specimens belonged to Assemblage B. Blastocystis spp. were the second most prevalent parasite in samples (29.5%), they were frequently detected in lettuce leaves (30.8%). Other parasites were found in low frequencies. The high level of parasitic contamination found in our study indicates an urgent need to identify the sources of contamination and to monitor irrigation water and ensure its cleanliness.

First report of 'Candidatus Liberibacter solanacearum' on carrot in Serbia

At the beginning of July 2020, three-month-old carrot plants (Daucus carota L. variety Maestro F1) grown in a commercial field 1.2 ha in size at the Begeč locality (45°14'30.38" N 19°36'44.82" E) in southern part of the Bačka region, Vojvodina, Serbia, exhibited symptoms of yellowing and reddish leaf discoloration. At the end of July, leaves on the infected plants became bronze and purplish, while their shoots and roots were stunted due to dehydration, with pronounced proliferation. In some cases, the damage was so extensive that it led to plant decay. The disease incidence of 0.5-1% recorded early in July rapidly escalated, reaching 10-15% in the first ten days of August. The observed symptoms resembled those caused by 'Candidatus Liberibacter solanacearum' (CaLso), a phloem-limited proteobacterium (1). To detect and identify CaLso, 15 symptomatic diseased and 5 asymptomatic healthy carrot plants were subjected to conventional polymerase chain reactions (PCR) using two primer sets specific to CaLso, and positive PCR products were further sequenced using commercial facilities (Macrogen Europe). Total DNA was extracted from petiole and root tissues using a commercial kit (Qiagen DNEasy Plant Mini Kit) following the manufacturer-recommended protocol. In the first PCR, using the Lso TX 16/23 F/R primer pair that targets the 16S-23S rRNA IGS region specific to CaLso (2), all 15 diseased samples yielded a band of 383 bp size. After sequencing, 100% homology was noted among tested isolates; therefore, one isolate coded as 1842/20 was chosen as representative and was deposited in NCBI GenBank under Accession number MT948144. BLAST analysis showed 99.70% identity of Serbian carrot isolates with those of the CaLso isolate 80022 originating from celery seed in Slovenia or Italy (Acc. no. KY619977) (3), as well as 99.41% identity with isolate GBBC_Clso_03 from carrot in Belgium (Acc. no. MH734515) and 98.22% identity with the sequence of the CaLso reference strain NZ082226 (Acc. no. EU834130) isolated from tomato in New Zealand (4). In the second PCR, species-specific forward primer LsoF empirically designed at the signature region of the 16S rRNA sequence of CaLso (5) in combination with the universal liberibacter reverse primer OI2c (6) yielded a target of 1163 bp size in all 15 diseased symptomatic carrot samples. Representative isolate 1842/20 was deposited in NCBI GenBank under Acc. no. MW187524. Based on the nucleotide BLAST analysis, the sequence of Serbian carrot isolate showed 100% identity with CaLso strains 16-004 and 16-011 originating from carrot in Finland (Acc. no. MG701014 and MG701015, respectively) and 99.64% identity with CaLso reference strain NZ082226 (Acc. no. EU834130). Five healthy asymptomatic carrot plant samples were negative for the presence of CaLso in both PCR tests employed in this work. To our knowledge, this is the first report of CaLso causing the disease in carrot in Serbia. These results suggest a wider distribution of this pathogen than previously reported in Europe. In 2014, Psyllid Bactericera trigonica (Hemiptera, Triozidae) was described for the first time as a potential vector for CaLso transmission in few localities, including Begeč (7). Considering that its vectors are presently unidentified, certain aspects of CaLso genomics, diversity, epidemiology and vector dynamics will be studied further in future investigations.

A Vegetable Dietary Pattern Is Associated with Lowered Risk of Gestational Diabetes Mellitus in Chinese Women

BACKGROUND

Identification of modifiable dietary factors, which are involved in the development of gestational diabetes mellitus (GDM), could inform strategies to prevent GDM.

METHODS

We examined the dietary patterns in a Chinese population and evaluated their relationship with GDM risk using a case-control study including 1,464 cases and 8,092 control subjects. Propensity score matching was used to reduce the imbalance of covariates between cases and controls. Dietary patterns were identified using factor analysis while their associations with GDM risk were evaluated using logistic regression models.

RESULTS

A "vegetable" dietary pattern was characterized as the consumption of green leafy vegetables (Chinese little greens and bean seedling), other vegetables (cabbages, carrots, tomatoes, eggplants, potatoes, mushrooms, peppers, bamboo shoots, agarics, and garlic), and bean products (soybean milk, tofu, kidney beans, and cowpea). For every quartile increase in the vegetables factor score during 1 year prior to conception, the first trimester, and the second trimester of pregnancy, the GDM risk lowered by 6% (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.89 to 0.99), 7% (OR, 0.94; 95% CI, 0.88 to 0.99), and 9% (OR, 0.91; 95% CI, 0.86 to 0.96).

CONCLUSION

In conclusion, our study suggests that the vegetable dietary pattern is associated with lower GDM risk; however, the interpretation of the result should with caution due to the limitations in our study, and additional studies are necessary to explore the underlying mechanism of this relationship.