Association of fresh vegetable and salt-preserved vegetable consumptions with estimated glomerular filtration rate.

OBJECTIVE: This study aimed to investigate the relationship between the consumption of fresh and salt-preserved vegetables and the estimated glomerular filtration rate (eGFR), which requires further research. METHODS: For this purpose, the data of those subjects who participated in the 2011-2012 and 2014 surveys of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and had biomarker data were selected. Fresh and salt-preserved vegetable consumptions were assessed at each wave. eGFR was assessed using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on plasma creatinine. Furthermore, a linear mixed model was used to evaluate associations between fresh/salt-preserved vegetables and eGFR. RESULTS: The results indicated that the median baseline and follow-up eGFRs were 72.47 mL/min/1.73 m² and 70.26 mL/min/1.73 m², respectively. After applying adjusted linear mixed model analysis to the data, the results revealed that compared to almost daily intake, occasional consumption of fresh vegetables was associated with a lower eGFR (ß=-2.23, 95% CI: -4.23, -0.23). Moreover, rare or no consumption of salt-preserved vegetables was associated with a higher eGFR (ß = 1.87, 95% CI: 0.12, 3.63) compared to individuals who consumed salt-preserved vegetables daily. CONCLUSION: Fresh vegetable consumption was direct, whereas intake of salt-preserved vegetables was inversely associated with eGFR among the oldest subjects, supporting the potential benefits of diet-rich fresh vegetables for improving eGFR.

Occurrence of Aliarcobacter spp. in fresh and pre-cut vegetables of common use in San José, Costa Rica.

Aliarcobacter is a Gram-negative rod that can cause disease in both animals and humans. Several studies have evidenced its presence in a wide variety of foods. Given that the number of foodborne illness outbreaks linked to the consumption of vegetables has increased worldwide and that there is a lack of information about the occurrence of Aliarcobacter spp. in these, the aim of this study was to evaluate its presence and the occurrence of virulence factors in both fresh and ready-to-eat vegetable samples. 180 vegetable samples from Costa Rica were analyzed for the presence of Aliarcobacter spp., including 90 pre-cut vegetable packages and 90 fresh vegetables. Two (2.2%) of the isolates from pre-cut vegetables and 19 (21.1%) of the isolates obtained from fresh vegetables were confirmed as Aliarcobacter spp. One of the isolates from the pre-cut vegetable samples was identified as A. butzleri. For the fresh vegetables, 11 isolates were identified as A. skirrowii, one as A. butzleri, and the 7 remaining isolates could not be identified at a species level. There is an 87.5% positivity for hecA and 93.8% for pldA, virulence genes in strains isolated from fresh produce, contrasting with an absolute absence from pre-cut vegetable-isolated strains. These results evidence the presence of Aliarcobacter on fresh and pre-cut vegetables from Costa Rica and the potential hazard it might represent for public health.

Development of a qPCR detection approach for pathogenic Burkholderia cenocepacia associated with fresh vegetables.

Natural environment serves as a reservoir for Burkholderia cepacia complex organisms, including the highly transmissible opportunistic human pathogen B. cenocepacia. Currently, there is a lack of an effective and quantitative method for B. cenocepacia detection in fresh food and other environmental niches. A quantitative real-time PCR (qPCR) detection method for B. cenocepacia bacteria was established in this study and validated using artificially inoculated fresh vegetable samples. Genome-wide comparative methods were applied to identify target regions for the design of species-specific primers. Assay specificity was measured with 12 strains of closely related Burkholderia bacteria and demonstrated the primer pair BCF6/R6 were 100% specific for detection of B. cenocepacia. The described qPCR assay evaluated B. cenocepacia with a 2 pg µl-1 limit of detection and appropriate linearity (R2 = 0.999). In 50 samples of experimentally infected produce (lettuce, onion, and celery), the assay could detect B. cenocepacia as low as 2.6 × 102 cells in each sample equal to 1 g. The established qPCR method quantitatively detects B. cenocepacia with high sensitivity and specificity, making it a promising technique for B. cenocepacia detection and epidemiological research on B. cepacia complex organisms from fresh vegetables.

Widespread Multidrug Resistance of Arcobacter butzleri Isolated from Clinical and Food Sources in Central Italy.

The Arcobacter genus comprises a group of bacteria widely distributed in different habitats that can be spread throughout the food chain. Fluoroquinolones and aminoglycosides represent the most common antimicrobial agents used for the treatment of Arcobacter infections. However, the increasing trend of the antimicrobial resistance of this pathogen leads to treatment failures. Moreover, the test implementation and interpretation are hindered by the lack of reference protocols and standard interpretive criteria. The purpose of our study was to assess the antibiotic resistance pattern of 17 A. butzleri strains isolated in Central Italy from fresh vegetables, sushi, chicken breast, and clinical human samples to provide new and updated information about the antimicrobial resistance epidemiology of this species. Antimicrobial susceptibility testing was carried out by the European Committee on Antimicrobial Susceptibility Testing (EUCAST)'s disc diffusion method. All the strains were multidrug resistant, with 100% resistance to tetracyclines and cefotaxime (third generation cephalosporins). Some differences were noticed among the strains, according to the isolation source (clinical isolates, food of animal origin, or fresh vegetables), with a higher sensitivity to streptomycin detected only in the strains isolated from fresh vegetables. Our data, together with other epidemiological information at the national or European Union (EU) level, may contribute to developing homogeneous breakpoints. However, the high prevalence of resistance to a wide range of antimicrobial classes makes this microorganism a threat to human health and suggests that its monitoring should be considered by authorities designated for food safety.

Salmonella and other Enterobacteriaceae in conventional and organic vegetables grown in Brazilian farms.

This study aimed to assess the microbiological profile of conventional and organic vegetables grown in Brazilian farms through the detection of Salmonella and other Enterobacteriaceae. A total of 200 samples (100 conventional and 100 organic), including leafy greens, spices/herbs, and other unusual vegetables, were submitted to the enumeration of Enterobacteriaceae by plating on VRBG agar. Moreover, colonies of Enterobacteriaceae were randomly selected and submitted to identification by MALDI-TOF MS. Samples were also tested for Salmonella, using culture-based and PCR-based enrichment methods. The mean counts of Enterobacteriaceae in conventional and organic vegetables were 5.1 ± 1.5 and 5.4 ± 1.4 log CFU/g, respectively (P > 0.05). A total of 18 genera (including 38 species) of Enterobacteriaceae were identified, and the most frequent ones found in samples from both farming systems were Enterobacter (76%) and Pantoea (68%). Salmonella was identified in 17 samples (8.5%): nine (4.5%) in conventional and eight (4.0%) in organic vegetables. These results indicate that the farming system had no impact on the Enterobacteriaceae populations and rates of Salmonella and revealed unsatisfactory microbiological safety of some samples, mainly due to the presence of Salmonella. These findings highlight the need for control measures during vegetable production, regardless of the farming system, to reduce microbial contamination and the risks of foodborne illnesses.

Microbiological analysis and characterization of Salmonella and ciprofloxacin-resistant Escherichia coli isolates recovered from retail fresh vegetables in Shaanxi Province, China.

Fresh vegetables are closely associated with foodborne disease outbreaks; however, systematic analysis of the microbiological quality of fresh vegetables and molecular information on foodborne pathogens in fresh produce are poorly reported in China. Here, we evaluated the epidemiological prevalence of coliforms via the most probable number method and characterized Salmonella and ciprofloxacin-resistant (CIPR) Escherichia coli isolates recovered from retail fresh vegetables in Shaanxi Province, China. Antimicrobial susceptibility testing, serotype determination, multilocus sequence typing (MLST), core genome multilocus sequence typing (cgMLST), antibiotic resistance encoding gene (ARG) annotation, virulence factor prediction, and functional classification were performed. Between October 2020 and September 2021, 576 samples (i.e., tomatoes, lettuces, spinaches, and cabbages) were found to be positive for coliforms, and the prevalence of coliforms showed a seasonal trend. Coliform counts of vegetables in supermarkets in Xi'an were significantly lower (P < 0.01) than that in other cities. The detection rates of Salmonella and CIPRE. coli-positive vegetables were 1 % (6/576) and 0.7 % (4/576), respectively. All isolates exhibited resistance to ≥1 antibiotics, and 92.9 % (13/14) were multidrug-resistant. One extended spectrum ß-lactamase (ESBL)-producing CIPRE. coli isolate in spinach was resistant to not only three third-generation cephalosporins but also to two polymyxins. Among nine Salmonella isolates, five different serovars (S. Enteritidis, S. Indiana, monophasic variant of S. Typhimurium, S. Agona, and S. Gallinarum), four sequence types (STs; ST11, ST13, ST17, and ST34), and seven core genome STs (cgSTs) were identified. Five CIPRE. coli strains were assigned to three serovars (O101:H4, O8:H18, and O11:H25), three STs (ST44, ST48, and ST457), and four cgSTs. Coexisting amino acid mutations of Thr57Ser/Ser80Arg in ParC and Ser83Phe/Asp87Gly in GyrA in quinolone resistance-determining regions (QRDRs) might be causes for nalidixic acid resistance. Eight definite virulence profiles in eight serovars were identified. Notably, cdtB and pltA only encoded typhoid toxins and were just detected from S. Typhoid isolates were also detected from S. Indiana and monophasic S. Typhimurium, which are closely associated with swine food chain were first detected in fresh vegetables. In conclusion, our findings suggest that coliform contamination on fresh vegetables is prevalent in this province. Most Salmonella and CIPRE. coli isolates were phenotypically and genetically diverse and could resist multiple antibiotics by carrying multiple ARGs and virulence genes.

Transmission of Cryptosporidium by Fresh Vegetables.

ABSTRACT: Consumption of fresh fruits and vegetables is increasing thanks to a greater awareness of the human health benefits. Vegetables may become contaminated by enteric pathogens (protozoan parasites, bacteria, and viruses) by irrigation with contaminated water, fertilization with fresh animal manure, or by infected food handlers. Cryptosporidium spp. are fecal-oral protozoan parasites, known to be highly persistent in the environment. Efficient methods were developed for releasing and concentrating Cryptosporidium oocysts from leafy vegetables, and sensitive and specific methods were applied for detection. The aims of this review are to discuss the development and optimization of methods applied to elute, concentrate, and detect oocysts from leafy vegetables, to review the prevalence of Cryptosporidium oocysts on fresh leafy vegetables from various parts of the world, and to discuss cryptosporidiosis outbreaks resulting from the consumption of leafy vegetables. Three solutions were used with comparable efficiency to release oocysts from leafy vegetables: 1 M glycine solution; 0.1% Alconox; and filter elution buffer, with an efficiency of 36.2, 72.6, and 44%, respectively. The prevalence of Cryptosporidium oocysts was reported in developed, as well as from developing countries, although simple detection methods were applied. Most of the cryptosporidiosis outbreaks were reported in developed countries, which can be related to the efficient surveillance system. Transmission of infectious pathogens, such as Cryptosporidium, may be facilitated by fresh vegetables, which are imported and transferred from less developed to highly developed countries and consumed uncooked. Monitoring of Cryptosporidium oocysts by sensitive detection methods may enhance measures to prevent transmission by freshly consumed vegetables.

Control of postharvest fungal diseases in fruits using external application of RNAi.

Contamination with a variety of filamentous fungi can cause deterioration of food and agricultural products. Fungal contaminations reduce the quality and the shelf life of fresh fruits and are one of the main causes of economic loss in the global fresh fruit industry. Although chemical fungicides are effective and traditionally used to control postharvest fungal diseases, they are harmful to human health. In this context, use of RNA interference (RNAi)-based fungicides is a promising alternative strategy. Spray-induced gene silencing (SIGS) is an innovative RNAi-based approach for silencing target genes in phytopathogens. This review aims to discuss the recent findings on the use of RNAi-based fungicides to control the postharvest spoilage of fresh fruits. PRACTICAL APPLICATION: Control of postharvest fungal diseases is one of the most important strategies to make food available to consumers longer. In this sense, the external application of RNAi seems to be technologically advantageous and efficient as it helps to maintain the characteristics of plant products. In this sense, this review discussed what is possible to find in the literature regarding this new technology.

[Status of fresh vegetables and fruit consumption among Chinese aged 60 years old and above in 2015].

OBJECTIVE: To analysis the fresh vegetables and fresh fruit consumption among the elders aged 60 and above of China in 2015. METHODS: The consumption of fresh vegetables and fresh fruits in the past 12 months was calculated by using the food frequency questionnaire data of 58 335 elderly people aged 60 and above from "China National Chronic Diseases and Nutrition Surveillance of Adults(2015)", and the intake status was evaluated according to the recommended intake of Dietary Guidelines for Chinese Residents(2016). RESULTS: The consumption rate of fresh vegetables among the elderly in China was 98. 7%, the median intake of the whole population was 270. 0 g, the median intake of the consumer population was 300. 0 g, and the proportion of under-intake was 49. 6%. The fresh fruit consumption rate was 84. 2%, the median intake of the whole population was 30. 0 g, and the median intake of the consumer population was 50. 0 g. The proportion of insufficient intake of fresh fruits reached 85. 2%. The frequency of intake of fresh vegetables was mainly 2 times/day, accounting for 45. 9%; fresh vegetables intake 1-3 times/week and ≥2 times/day were 38. 7% and 35. 6%, respectively. The consumption rate and intake of fresh vegetables and fruits were both higher in urban areas than in rural areas, and decrease significantly with increasing age, lower educational background and lower income. In addition, the consumption rate and intake were lower in elderly living alone. CONCLUSION: China& apos; s elderly people aged 60 and above have insufficient intake of vegetables and fruits. Health education and dietary guidance should be carried out, and intervention measures should be taken for key populations to effectively promote a reasonable diet for the elderly.

ONE HEALTH: ANTIBIOTIC-RESISTANT BACTERIA CONTAMINATION IN FRESH VEGETABLES SOLD AT A RETAIL MARKETS IN KYIV, UKRAINE.

OBJECTIVE: The aim: To obtain the first estimates data on the occurrence of antibiotic-resistant bacteria in a wide range of fresh vegetables available in the Kyiv city markets. PATIENTS AND METHODS: Materials and methods: We performed a multicenter study. Fresh vegetables samples were collected of the six different commodity groups from eleven of retail stores locatedin Kyiv, Ukraine. Samples were tested for up to eight bacteria of concern. The susceptibility to antibiotics was determined by disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing. RESULTS: Results: The antibiotic-resistant bacteria contamination in the fresh vegetables was 24.3%. The contamination among organic produce was significantly higher than in conventionally products. Contamination was found to be higher in leafy vegetables. The predominant contaminated bacteria were: Escherichia coli, Enterobacter spp. And Enterococcus faecalis, followed by Klebsiella pneumoniae, Pseudomonas aeruginosa, E. faecium, Staphylococcus aureus and Acinetobacter spp. The overall proportion of extended spectrum beta-lactamase (ESBL) production among Enterobacteriaceae was 36.8% and of methicillin-resistance in S. aureus (MRSA) 10.7%. The prevalence of ESBL production among E. coli isolates was significantly higher than in K. pneumoniae. Vancomycin resistance was observed in 3.1% of isolated enterococci (VRE). Carbapenem resistance was identified in 35.3% of P.aeruginosa isolates and 66.8% of Acinetibacter spp. isolates. Resistance to third-generation cephalosporins was observed in 9.7% K. pneumoniae and E.coli in 14.2% isolates. CONCLUSION: Conclusions: Research has shown that the majority of fresh vegetables available in Kiev markets is contaminated with antibiotic-resistant bacteria and is a potential vehicle for the transmission of these pathogens to consumers.

Ozone Treatments for Preserving Fresh Vegetables Quality: A Critical Review.

Ozone is recognized as an antimicrobial agent for vegetables storage, washing, and processing. This strong disinfectant is now being used in the food industry. In this review, the chemical and physical properties of ozone, its generation, and factors affecting ozone processing efficiency were explained as well as recent regulatory developments in the food industry. By then selecting three vegetables, we show that ozone avoids and controls biological growth on vegetables, keeping their attractive appearance and sensorial qualities, assuring nutritional characteristics' retention and maintaining and increasing the shelf-life. In liquid solution, ozone can be used to disinfect processing water and vegetables, and in gaseous form, ozone helps to sanitize and preserve vegetables during storage. The multifunctionality of ozone makes it a promising food processing agent. However, if ozone is improperly used, it causes some deleterious effects on products, such as losses in their sensory quality. For an effective and a safe use of ozone, specific treatment conditions should be determined for all kinds of vegetables. In a last step, we propose highlighting the different essential characteristics of ozone treatment in order to internationally harmonize the data relating to the treatments carried-out.

Sustainability assessment with structural equation modeling in fresh food supply chain management.

The aim of this study is to determine the dimensions that affect the sustainability performance of the fresh vegetable and fruit supply chain and to determine the performance that occurs along the chain line. In this study conducted for the fresh fruit and vegetable sector, it is desirable to measure each dimension by finding the performance indices of sustainable supply chain management. Dimensions of this study include supply chain management, resource management, food safety, packaging, and waste management. For these five dimensions gathered from the literature and expert opinions, 26 sub-criteria are determined for use in performance evaluation. Structural equation modeling (SEM) and analytical hierarchy process (AHP) methods are used together to calculate the performance index of each dimension and then to obtain a final fresh vegetable and fruit supply chain performance score. This study has been performed in Turkey. Turkey, between the countries of the world, is located in the top 5 in the fruit and vegetable production. The performance of the five different dimensions is calculated. In this performance assessment, supply chain management dimension is calculated as the highest performance with a score of 91.22%. The lowest performance index score as 66.77% is the waste management dimension. The final sustainable fresh fruit and vegetable supply chain performance score is calculated as 79.96%. In addition to the limited performance evaluation studies in the sustainable supply chain, the fact that this study deals with the food chain, modeling and creating a final performance demonstrates the innovative aspect of the study. Attention is also drawn to the parameters that need to be addressed for more sustainable food.

Detection of Infectious Cryptosporidium parvum Oocysts from Lamb's Lettuce: CC-qPCR's Intake.

Cryptosporidium spp. is responsible for several food and waterborne disease outbreaks worldwide. Healthier lifestyles attract consumers to eat, notably, fresh food like fruits and vegetables. The consumption of raw or under-cooked food increases the risk of foodborne transmission of Cryptosporidiosis. The assessment of the consumer's exposure to Cryptosporidium danger is crucial for public health. Still, the standardized method to detect this parasite in fresh leafy greens and berry fruits has only been available since 2016 and suffers from weaknesses. Consequently, in this study, we propose a method with minimum processing steps that combines cell culture and the quantitative PCR (CC-qPCR) for detecting infectious C. parvum oocysts recovered from lamb's lettuce. This CC-qPCR is a rapid and easy method that can detect up to one oocyst, whereas it is undetectable by classic qPCR.

Prevalence of ESBL, AmpC and Carbapenemase-Producing Enterobacterales Isolated from Raw Vegetables Retailed in Romania.

(1) Background: As ß-lactamase-producing Enterobacterales are no longer exclusively associated with the health care system, investigating the potential risk they pose to the integrity of the environment and food safety has become of utmost importance. This study aimed to determine the prevalence of extended-spectrum ß-lactamase (ESBL), AmpC, and carbapenemase-producing Enterobacterales isolates from retailed raw vegetables and to determine if household washing is an effective method of lowering bacterial load; (2) Methods: Seasonal vegetables (n = 165) were acquired from supermarkets (n = 2) and farmer markets (n = 2) in Romania. Following sample processing and isolation, identification of Enterobacterales was performed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF). Polymerase chain reaction (PCR) multiplex was used to ascertain the presence of the main ESBL, AmpC, and Carbapenemase genes. Phenotypic antibiotic resistance profiles of isolates were determined by extended antibiograms. Enterobacteriaceae colony-forming units (CFU) counts were compared between vegetable types; (3) Results: Beta-lactamase producing bacteria were observed on 7.9% of vegetables, with 5.5% displaying ESBL/AmpC phenotype and 2.4% identified as Carbapenemase producers. The most frequently detected ß-lactamase genes were blaSHV (n = 4), followed by blaCTX-M and blaTEM (each with n = 3). Phenotypic antibiotic resistance analysis showed that 46% of isolates were multiple drug resistant, with aminoglycosides (38.5%) the most prevalent non-ß-lactam resistance, followed by first-generation quinolones (38.5%). (4) Conclusions: The present study has described for the first time the presence of ß-lactamase producing Enterobacterales in fresh produce retailed in Romania.

The effect of essential oils and their combinations on bacteria from the surface of fresh vegetables.

During the study, we determined the antimicrobial activity of different selected essential oils (thyme, lemongrass, juniper, oregano, sage, fennel, rosemary, mint, rosehips, dill) on some pathogenic and spoilage bacteria isolated from the surface of various fresh vegetables. At the same time, in the case of some volatile oil combinations we followed the phenomena of synergism and antagonism. The identification of the isolated bacterial strains was made using 16S rDNA gene sequence analysis. The most resistant isolates appeared to be Curtobacterium herbarum, Achromobacter xylosoxidans, and Enterobacter ludwigii, while Pseudomonas hibiscicola was the most sensitive. Of the chosen plant essential oils, the most pronounced antimicrobial effect was detected in the case of oregano. The essential oils of thyme and mint also showed elevated antimicrobial activity. A synergistic effect was observed in case of five combinations of essential oil. Based on the results, we find that some individual essential oils and mixture compositions (due to synergic effect) could be good candidates for the preservation of fresh vegetables. These preliminary findings suggest that essential oils from locally grown spices could contribute to decreasing the health risk and also to the suppression of emergence of antibiotic resistance.

Handling of Fresh Vegetables: Knowledge, Hygienic Behavior of Vendors, Public Health in Maputo Markets, Mozambique.

In developing countries, markets are the main supply of horticultural products to populations, but this can pose a public health challenge due to the risk of the fecal-oral transmission of gut pathogens. This transmission is strongly associated with inadequate public sanitation or low standards of personal and domestic hygiene, and their prevalence can cause gastrointestinal diseases, which are the third leading cause of death in Mozambique. This study aims at assessing the risk for public health of horticultural products supply chain, from the farmers-vendors to the consumers, in municipal markets in Maputo-City, Mozambique. Surveys (75) were conducted on vendors and an observational analysis was performed in the markets under study. The results showed that 62% of the vendors had access to water from boreholes or artisanal sources and the issue "access to water" was significantly different between markets (p = 0.004). Of the vendors who wash their products (53.3%), only 7.5% use tap-water for this purpose, with the difference in attitudes being statistically significant between vendors in the markets (p = 0.035). The majority (60.4%) said that vegetables and fruits can cause diseases due to pesticides and only 31.3% believe that the diseases may be related to poor hygiene. Despite the vendors' low knowledge of Good Hygiene Practices (GHP), we noticed that women have better practical assimilation of GHP when compared to men (p = 0.008). Although Maputo's markets are struggling to achieve quality hygiene standards in a reliable and sustainable manner, their resources are limited and significantly different (p = 0.044) from market to market, and this problem remains a concern for the public-health authorities of the city. In conclusion, the provision of adequate drinking water and sewage disposal systems, together with education for health of vendors, can reduce the risk of contamination of fresh food by the more common organisms causing diarrhea in children, including intestinal parasites.

Cryptosporidium spp., Giardia duodenalis and Toxoplasma gondii detection in fresh vegetables consumed in Marrakech, Morocco.

BACKGROUND: Protozoan parasites such as Toxoplasma gondii, Giardia duodenalis, and Cryptosporidium spp., can be transmitted to humans via accidental consumption of contaminated water, fresh produce and foodstuffs. There is a lack of epidemiological data about these pathogens in Morocco. Hence the aim of this study, which is the determination of their prevalence in some leafy greens and root vegetables sold in Marrakech. METHODS: A total of 132 vegetable samples including carrot, coriander, lettuce, parsley and radish were purchased monthly from three different markets in Marrakech from March 2017 to January 2018, pre-treated and subjected to microscopic and molecular analyses. RESULTS: Of the 132 samples of vegetables analyzed by qPCR, the overall rate of protozoan was 21.21% (28/132); 22 samples were found to be contaminated with T. gondii, 6 with G. duodenalis, and none was positive for C. parvum/hominis. Whereas, modified Ziehl-Neelsen staining allowed the detection of Cryptosporidium spp. in 3% (4/132) of examined samples. CONCLUSION: This survey on the presence of protozoan parasites in fresh vegetables revealed that vegetables sold in Marrakech are contaminated by these protozoan parasites, as it showed that leafy green vegetables were more susceptible for parasitic contamination than root ones.

Biopreservation approaches to reduce Listeria monocytogenes in fresh vegetables.

Two biopreservation approaches for fresh lettuce, rocket salad, parsley and spinach were studied. The potential of Pediococcus pentosaceus DT016, as a protective culture, to suppress Listeria monocytogenes in vegetables during storage was evaluated. The pathogen numbers in the vegetables inoculated with P. pentosaceus DT016 were significantly (p < 0.01) lower throughout the storage period and, at the last storage day, a minimum difference of 1.4 log CFU/g was reported when compared with the vegetables without the protective culture. Moreover, by using two levels of L. monocytogenes (about 6 and 4 log CFU/g), it was observed that the antagonist effect of P. pentosaceus was higher for the lower pathogen numbers. The second approach evaluated a pediocin DT016 solution to inactivate and control L. monocytogenes proliferation. The pathogen load was studied after washing with: water, chlorine and the pediocin solution and along storage at 4  °C. Comparing the various washing solutions, the vegetables washed with pediocin presented significantly (p < 0.01) lower pathogen numbers throughout storage, by a minimum of 3.2 and 2.7 log CFU/g, than in vegetables washed with water and chlorine, respectively. The proposed methodologies are promising alternatives to maintain the safety of fresh vegetables during extended storage at refrigeration temperature.

Experimentation on artificial inoculation studies for persistence of shiga-like toxin-producing Escherichia coli (E. coli O157) in agricultural soils and vegetables using real-time PCR.

Diarrheagenic Escherichia coli O157 is an important reason for largest food borne inflectional outbreaks. E. coli O157 invades into the food chain through contaminated irrigation water and soil causing infectious diseases to humans. In our previous study, we have evaluated the persistence of E. coli O157 through plate count methods. However, conventional cultural procedures are less sensitive to discriminate the pathogenic strain and are time consuming. Therefore, in the present study we have enumerated the persistence of E. coli O157 in soil and vegetables using specific shiga toxin genes (stx1, stx2) through quantitative PCR. Initially, we have standardized a simple Sephadex-based DNA extraction protocol that could detect 2-3 cells/25g of vegetables. Further, quantitative PCR analysis showed a 103 fold difference in the enumeration of persistence as compared to simple plating techniques. Thus, qPCR-based persistence study can be used for rapid and accurate detection techniques for analyzing E. coli O157 contamination. PRACTICAL APPLICATIONS: Our experiment on E. coli O157 expression could be used as a scale for further studies on E. coli O157 pollution in the cropped soils, additionally the DNA extraction protocol experimented by us could be used in all sensitive quantitative assays, as it could detect the expression in lowest cell loads. However, our methodology is a more reliable and sensitive assay compared to normal cultural methods. Our experiment provides a strong evidence of persistence of E. coli O157 prevailing up to half or full cropping season.

Prevalence of Extended-Spectrum ß-Lactamase-Producing Bacteria on Fresh Vegetables in Japan.

Extended-spectrum ß-lactamase (ESBL)-producing bacteria are spreading rapidly, posing a threat to human and animal health. Contamination of vegetables with antimicrobial-resistant bacteria or those harboring antimicrobial resistance genes or a combination of both presents a potential route of transmission to humans. Therefore, the aim of this study was to determine the prevalence of these bacteria in fresh vegetables in Japan. A total of 130 samples of fresh vegetables were collected from seven supermarkets in Japan. The predominant genus detected was Pseudomonas spp., including 10 ESBL-producing strains, isolated from 10 (7.7%) of the vegetable samples. Two ESBL genes were detected, blaTEM-116 (n = 7) and blaSHV-12 (n = 3), and some of these strains were resistant to multiple antibiotics. Because vegetables are often consumed raw, those contaminated with ESBL producers could represent an important route of transmission to humans in Japan. Thus, more stringent hygiene measures and monitoring are required to prevent transmission via this source.