المؤلفون: Giovanni Beccari, Francesco Tini, Nora A. Foroud, Luisa Ederli, Donald M. Gardiner, Aurelie H. Benfield, Linda J. Harris, Michael Sulyok, Roberto Romani, Ilaria Bellezza, Lorenzo Covarelli

المصدر: BMC Plant Biology, Vol 24, Iss 1, Pp 1-17 (2024)

مصطلحات موضوعية: Fusarium, Cereals, Mycotoxins, Secondary metabolites, Fusarium head blight, Botany, QK1-989

الوصف: Abstract Background Fusarium graminearum and Fusarium avenaceum are two of the most important causal agents of Fusarium head blight (FHB) of wheat. They can produce mycotoxins that accumulate in infected wheat heads, including deoxynivalenol (DON) and enniatins (ENNs), produced by F. graminearum and F. avenaceum, respectively. While the role of DON as a virulence factor in F. graminearum toward wheat is well known, ENNs in F. avenaceum has been poorly explored. Results obtained to-date indicate that ENNs may confer an advantage to F. avenaceum only on particular hosts. Results In this study, with the use of ENN-producing and ENN non-producing F. avenaceum strains, the role of ENNs on F. avenaceum virulence was investigated on the root, stem base and head of common wheat, and compared with the role of DON, using DON-producing and DON non-producing F. graminearum strains. The DON-producing F. graminearum strain showed a significantly higher ability to cause symptoms and colonise each of the tested tissues than the non-producing strain. On the other hand, the ability to produce ENNs increased initial symptoms of the disease and fungal biomass accumulation, measured by qPCR, only in wheat heads, and not in roots or stem bases. LC-MS/MS analysis was used to confirm the presence of ENNs and DON in the different strains, and results, both in vitro and in wheat heads, were consistent with the genetics of each strain. Conclusion While the key role of DON on F. graminearum virulence towards three different wheat tissues was noticeable, ENNs seemed to have a role only in influencing F. avenaceum virulence on common wheat heads probably due to an initial delay in the appearance of symptoms.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1471-2229Test

الوصول الحر: https://doaj.org/article/ed0abde0ad48410c9be8dca439c96e8cTest

المؤلفون: Yucen Xie, Xiaonuo Long, Yoonbin Kim, Linda J. Harris, Nitin Nitin

المصدر: Journal of Food Protection, Vol 87, Iss 7, Pp 100292- (2024)

مصطلحات موضوعية: Desiccation stability, Dry environment, Food contact surfaces, Pathogens, Produce extract, Food processing and manufacture, TP368-456, Nutrition. Foods and food supply, TX341-641

الوصف: Currently, there is limited knowledge on the survival of bacteria on surfaces during postharvest handling of dry products such as onions. Extended survival of microorganisms, coupled with a lack of established and regular, validated cleaning or sanitation methods could enable cross-contamination of these products. The aim of the study was to evaluate the survival of a potential surrogate, Enterococcus faecium, and Salmonella enterica on typical onion handling surfaces, polyurethane (PU), and stainless steel (SS), under low relative humidity. The influence of onion extract on the survival of E. faecium and Salmonella on PU and SS was also investigated. Rifampin-resistant E. faecium NRRL B-2354 and a five-strain cocktail of Salmonella suspended in 0.1% peptone or onion extract were separately inoculated onto PU and SS coupons (2 × 2 cm), at high, moderate, or low (7, 5, or 3 log CFU/cm2) levels. The inoculated surfaces were stored at ∼34% relative humidity and 21°C for up to 84 days. Triplicate samples were enumerated at regular intervals in replicate trials. Samples were enriched when populations fell below the limit of detection by plating (0.48 log CFU/cm2). Scanning electron microscopy was used to observe the cell distribution on the coupons. Reductions of E. faecium of less than ∼2 log were observed on PU and SS over 12 weeks at all inoculum levels and with both inoculum carriers. In 0.1% peptone, Salmonella populations declined by 2 to 3 log over 12 weeks at the high and moderate inoculum levels; at the low inoculum level, Salmonella could not be recovered by enrichment at 84 days. Survival of E. faecium and Salmonella was significantly (P

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0362028X24000760Test; https://doaj.org/toc/0362-028XTest

الوصول الحر: https://doaj.org/article/af09f35c380f4af99d7453500d45c4c5Test

المؤلفون: Erika M. Estrada, Linda J. Harris

المصدر: Journal of Food Protection, Vol 87, Iss 5, Pp 100268- (2024)

مصطلحات موضوعية: Biofilm formation, CHASRI, Desiccation, Rdar morphotype, Storage survival, Food processing and manufacture, TP368-456, Nutrition. Foods and food supply, TX341-641

الوصف: Salmonella enterica subsp. enterica strain diversity in California pistachios is limited; some strains have persisted in the pistachio supply chain for ≥10 years. Representative isolates of six persistent strains and three sporadic strains isolated from California pistachios were selected to evaluate copper resistance, growth in pistachio hull slurry, biofilm formation, desiccation tolerance, and survival during subsequent storage. The presence of a copper homeostasis and silver-resistance island sequence in three of the persistent strains was associated with an increase in tolerance to CuSO4 from 7.5 mM to 15 mM under anaerobic but not aerobic conditions; all isolates were resistant to ≥120 mM Cu-EDTA under both anerobic and aerobic conditions. When inoculated into pistachio hull slurry at 2.75 ± 0.04 log CFU/mL and incubated at 30 °C, the populations of Salmonella Enteritidis strain A (sporadic) increased to significantly lower levels than the other strains at 16, 20, 24, and 28 h but not at 40 and 48 h. Maximum populations of 8.70–8.85 log CFU/mL were observed for all strains at ≥40 h of incubation. All nine Salmonella strains produced weak to strong biofilms after 4 days at 25 °C; seven strains, including two sporadic strains, produced moderate biofilms, and Salmonella Liverpool strain A (persistent) produced a strong biofilm. The rdar+ and rdar- morphotypes were observed in both persistent and sporadic Salmonella strains. Population declines of 5.03 log were observed for Salmonella Enteritidis strain A within 18 h of drying on filter paper whereas reductions of 0.50–1.25 log were observed for the other eight Salmonella strains. Population reductions (3.98–5.12 log) of these eight strains were not significantly different after storage at 25 ± 1 °C and 35% relative humidity for 50 days. The phenotypic characteristics evaluated here do not independently account for the persistence of a small number of Salmonella strains associated with the California pistachio production chain.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0362028X24000528Test; https://doaj.org/toc/0362-028XTest

الوصول الحر: https://doaj.org/article/86f4fe81fd994fcb8db3c46b04f9c7b2Test

المؤلفون: Hanna S. Louvau, Hongye Wang, Maria M. Shaposhnikov, Linda J Harris

المصدر: Journal of Food Protection, Vol 87, Iss 8, Pp 100311- (2024)

مصطلحات موضوعية: Dairy analog, Fermentation, Pathogen, Plant-based, Food processing and manufacture, TP368-456, Nutrition. Foods and food supply, TX341-641

الوصف: Between 2013 and 2021, there were three reported salmonellosis outbreaks in North America linked to the consumption of cashew cheese analogs that were prepared from soaked and fermented cashews. The behavior of Salmonella was evaluated during fermentation of cashews to better understand the risks associated with plant-based fermentations. Single or seven-strain rifampin-resistant Salmonella-inoculated cashews (1–2 log CFU/g) were soaked 1:1 (w/v) in sterile ultrapure water at 4 °C for 24 ± 1 h, drained, and then blended with additional water. Salmonella-inoculated or uninoculated cashews with or without added commercial Lactococcus lactis starter culture (LAB), and with LAB and NaCl (0.8% and 1.6% w/w), citric acid (0.4% w/w), or a combination of NaCl and citric acid, were held at 24 ± 1 °C for up to 72 h. The pH, aerobic plate counts (M17 agar), and Salmonella populations (CHROMagar Salmonella with 50 µg/mL of rifampin) were measured at 0, 24, 48, and 72 h in replicate experiments. When LAB was present, aerobic plate counts increased from ∼8 log CFU/g to ∼9 log CFU/g after 24 h. The pH decreased from an initial pH ∼6 to pH 4.5–5.0 at 24 h in the presence of LAB or at 48 h in the absence of LAB. The presence of LAB significantly (P

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0362028X24000954Test; https://doaj.org/toc/0362-028XTest

الوصول الحر: https://doaj.org/article/35376dab23954a16809228b70825613bTest

المؤلفون: Hongye Wang, Lina Sheng, Zhuosheng Liu, Xiran Li, Linda J. Harris, Luxin Wang

المصدر: Journal of Food Protection, Vol 87, Iss 4, Pp 100255- (2024)

مصطلحات موضوعية: Citrus wax, Enterococcus faecium NRRL B-2354, Listeria monocytogenes, Salmonella, Storage, Food processing and manufacture, TP368-456, Nutrition. Foods and food supply, TX341-641

الوصف: After finishing waxes are applied, citrus fruits are typically dried at 32–60°C for 2–3 min before final packing. The survival of Listeria monocytogenes, Salmonella, and Enterococcus faecium NRRL B-2354 was evaluated under laboratory conditions on lemons after applying one of four finishing waxes (F4, F6, F8, and F15) followed by an ambient hold or heated (50 or 60°C) drying step. The reduction of inoculated microorganisms during drying was significantly influenced by wax type and temperature, with greater reductions at higher temperatures. Greater reductions after waxing and drying at 60°C were observed with L. monocytogenes (2.84–4.44 log) than with Salmonella (1.65–3.67 log), and with Salmonella than with E. faecium (0.99–2.93 log). The survival of Salmonella inoculated at 5.8–5.9 log/fruit on lemons and oranges after applying wax F6 and drying at 60°C was evaluated during storage at 4 and 22°C. The reductions of Salmonella after waxing and drying were 1.7 log; additional reductions during storage at 4 or 22°C were 1.40–1.43 or 0.18–0.29 log, respectively, on waxed lemons, and 0.56–1.02 or 0.54–0.57 log, respectively, on waxed oranges. Under pilot-scale packinghouse conditions with wax F4, mean and minimum reductions of E. faecium ranged from 2.15 to 2.89 and 1.64 to 2.12 log, respectively. However, E. faecium was recovered by whole-fruit enrichment (limit of detection: 0.60 log CFU/lemon) but not by plating (LOD: 1.3 log CFU/lemon) from uninoculated lemons run with or after the inoculated lemons. The findings should provide useful information to establish and implement packinghouse food safety plans.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0362028X24000395Test; https://doaj.org/toc/0362-028XTest

الوصول الحر: https://doaj.org/article/ccd7aaebd3804a30bfcde22a7458ed47Test

المؤلفون: Erika M. Estrada, Anne-laure Moyne, Linda J. Harris

المصدر: Journal of Food Protection, Vol 86, Iss 10, Pp 100143- (2023)

مصطلحات موضوعية: Foodborne Pathogen, Persistence, SNP Analysis, Tree Nuts, Food processing and manufacture, TP368-456, Nutrition. Foods and food supply, TX341-641

الوصف: The genetic diversity of 169 Salmonella isolates from pistachios collected from California storage silos during the 2010, 2011, and 2012 harvests (silo survey isolates) was determined by analyzing the whole genome sequence data using the CFSAN SNP pipeline developed by the U.S. Food and Drug Administration’s Center for Food Safety and Applied Nutrition. Salmonella isolates clustered by serovars Agona, Enteritidis, Montevideo, Sandiego, Senftenberg, Liverpool, Tennessee, and Worthington in the phylogenetic tree. Within each serovar, isolates grouped into one or two clusters (≤14 SNPs). Two distinct clusters (>14 SNPs; A and B) were identified for Salmonella Enteritidis, Montevideo, and Liverpool for a total of 11 unique strains. Sequences of representative silo survey isolates clustered with sequences of Salmonella strains isolated from U.S. pistachio-associated samples collected between 2008 and 2018 available on the National Center for Biotechnology Information database, and, in all but two cases, not with sequences of Salmonella strains recovered from raw California almonds from 2001 through 2013. The genomic evidence suggests that strains of Salmonella Agona, Liverpool Cluster A, Montevideo Clusters A and B, Senftenberg, and Worthington have persisted in the California pistachio environment for ≥3 years and some of these strains have been reported exclusively in association with pistachios.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0362028X23068278Test; https://doaj.org/toc/0362-028XTest

الوصول الحر: https://doaj.org/article/f8c2478f55404ea689a6a9afba9cbfaaTest

المؤلفون: Maeve Swinehart, Linda J. Harris, Nathan M. Anderson, Yaohua Feng

المصدر: Journal of Food Protection, Vol 86, Iss 9, Pp 100132- (2023)

مصطلحات موضوعية: Fermentation, Food safety, Low-moisture foods, Needs assessment, Survey, Tree nuts, Food processing and manufacture, TP368-456, Nutrition. Foods and food supply, TX341-641

الوصف: Tree nuts, a low-moisture food, are typically perceived as being a low risk for foodborne illness. In the past five decades, the consumption of tree nuts (dry, soaked, or as nut-based dairy analogs [NBDA]) has increased along with corresponding foodborne illness outbreaks and recalls associated with these products. We developed an online survey to assess tree nut handling practices of U.S. consumers, and to select study participants who have soaked tree nuts and/or made NBDA at home. We distributed our initial survey questions in October 2021 to a convenience sample (n = 12) to test for clarity and comprehension. In January 2022, participants (n = 981) who met the criteria completed the survey. The most popular soaked tree nuts were almonds (54%), followed by cashews (36%), walnuts (32%), and pistachios (22%). Participants soaked tree nuts for direct consumption (67%) and during the preparation of NBDA (80%). Participants soaked tree nuts under refrigerated conditions for 1–24 h (22%), on the countertop at room temperature (est. 65–75°F [18–24°C]) for 1–5 h (21%), or at room temperature for 12 h or more (6%); 16% used a hot or boiling water, short time treatment. Some participants added acid (28%) or salt (25%) to the soaking water. Among those participants who dried their tree nuts after soaking (63%), 89% reported drying at a temperature lower than 46°C (115°F). Some participants (34%) used their tree nuts to make fermented dairy analogs (e.g., “cheese” or “yogurt”) by adding “probiotics” (56–86%) or a yogurt starter culture (37–99%), respectively, and then, most frequently, holding at or below 20°C (68°F) for 12 h or less (29%). The safety of many of these practices has not been adequately investigated, but the findings of this study will inform future risk assessment and risk modeling studies on tree nut food safety in home kitchen settings.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0362028X23068163Test; https://doaj.org/toc/0362-028XTest

الوصول الحر: https://doaj.org/article/dc7e312419d54d3aa5646e897f495ad0Test

المؤلفون: Hanna Louvau, Linda J. Harris

المصدر: Journal of Food Protection, Vol 86, Iss 8, Pp 100109- (2023)

مصطلحات موضوعية: Low moisture, Most probable number, Outbreak, Pathogen, Prevalence, Tree nuts, Food processing and manufacture, TP368-456, Nutrition. Foods and food supply, TX341-641

الوصف: Raw materials associated with foodborne illness outbreaks are rarely available for evaluation. The levels and distribution of Salmonella were determined in naturally contaminated raw cashews linked to a salmonellosis outbreak associated with a fermented cashew cheese analog. Two unopened 22.7-kg boxes from a single lot of cashew kernel pieces were each divided into seven approximately equal units, 14 in total. Three 10-g subsamples per unit (n = 21) were evaluated for aerobic plate count (APC), coliform counts, and Escherichia coli counts, and 10 50-g subsamples per unit (n = 70) were enriched for the presence of Salmonella. Presumptive Salmonella-positive colonies were confirmed using CHROMagar Salmonella and real-time PCR (invA) and then serotyped using antigenic methods and genome sequencing prediction tools. APC and coliform counts ranged from 1.81 to 5.47 (mean 2.44 ± 0.63) log CFU/g and 0.60 to 5.20 (mean 1.74 ± 0.80) log CFU/g, respectively. Salmonella was recovered from four units in Box 1 and all seven units in Box 2. One of the 10 subsamples was positive in all but four of the positive units; one (Box 1) and three (Box 2) units had two positive subsamples. The level of Salmonella in the two boxes combined was 0.0023 most probable number/g (95% confidence interval [0.0014, 0.0038]). Salmonella Urbana was isolated from three of five positive subsamples in Box 1 and eight of 10 positive subsamples in Box 2. Salmonella Fresno and Vinohrady were unique to single subsamples from Box 1, and Salmonella Nima was isolated from two subsamples from Box 2. Of the four serovars recovered, Salmonella Urbana and Salmonella Vinohrady were in common with outbreak-associated clinical or product isolates. Understanding the distribution and concentration of Salmonella in naturally contaminated cashews provides important information for hazard analysis and risk assessments for soaked and fermented cashew products.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S0362028X23067819Test; https://doaj.org/toc/0362-028XTest

الوصول الحر: https://doaj.org/article/bd5d1af89be04d98b9bd66ce34bc8149Test

المؤلفون: Xi Wu, Anne-laure Moyne, Thais De Melo Ramos, Linda J. Harris, Erin DiCaprio

المصدر: Frontiers in Plant Science, Vol 14 (2023)

مصطلحات موضوعية: norovirus, produce, irrigation water, soil, tulane virus (TV), murine norovirus (MNV), Plant culture, SB1-1110

الوصف: IntroductionThe impact of water quality on the survival of human norovirus (NoV) was determined in irrigation water field run-off (tail water) and well water from a representative Central Coast vegetable production site in the Salinas Valley, California.MethodsTail water, well water, and ultrapure water samples were inoculated separately with two surrogate viruses for human NoV—Tulane virus (TV) and murine norovirus (MNV)—to achieve a titer of 1×105 plaque forming units (PFU)/ml. Samples were stored at 11, 19, and 24°C for 28 days. Additionally, inoculated water was applied to soil collected from a vegetable production site in the Salinas Valley or to the surface of growing romaine lettuce leaves, and virus infectivity was evaluated for 28 days in a growth chamber.ResultsVirus survival was similar for water stored at 11, 19, and 24°C and there was no difference in infectivity based on water quality. After 28 days, a maximum 1.5 log reduction was observed for both TV and MNV. TV decreased by 1.97-2.26 log and MNV decreased by 1.28- 1.48 logs after 28 days in soil; infectivity was not influenced by water type. Infectious TV and MNV were recovered from lettuce surfaces for up to 7 and 10 days after inoculation, respectively. Across the experiments there was no significant impact of water quality on the stability of the human NoV surrogates.DiscussionOverall, the human NoV surrogates were highly stable in water with a less than 1.5 log reduction over 28 days and no difference observed based on the water quality. In soil, the titer of TV declined by approximately 2 logs over 28 days, while MNV declined by 1 log during the same time interval, suggesting surrogate-specific inactivation dynamics in the soil tested in this study. A 5-log reduction in MNV (day 10 post inoculation) and TV (day 14 post inoculation) was observed on lettuce leaves, and the inactivation kinetics were not significantly impacted by the quality of water used. These results suggest that human NoV would be highly stable in water, and the quality of the water (e.g., nutrient content, salinity, and turbidity) does not significantly impact viral infectivity.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2023.1128579/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/8a7dee04acac4ab1a7a786fd2881b760Test

المؤلفون: Anne-Laure Moyne, Opeyemi U Lawal, Jeff Gauthier, Irena Kukavica-Ibrulj, Marianne Potvin, Lawrence Goodridge, Roger C Levesque, Linda J Harris

المصدر: PLoS ONE, Vol 18, Iss 9, p e0291109 (2023)

مصطلحات موضوعية: Medicine, Science

الوصف: A comparative genomic analysis was conducted for 171 Salmonella isolates recovered from raw inshell almonds and raw almond kernels between 2001 and 2013 and for 30 Salmonella Enteritidis phage type (PT) 30 isolates recovered between 2001 and 2006 from a 2001 salmonellosis outbreak-associated almond orchard. Whole genome sequencing was used to measure the genetic distance among isolates by single nucleotide polymorphism (SNP) analyses and to predict the presence of plasmid DNA and of antimicrobial resistance (AMR) and virulence genes. Isolates were classified by serovars with Parsnp, a fast core-genome multi aligner, before being analyzed with the CFSAN SNP Pipeline (U.S. Food and Drug Administration Center for Food Safety and Applied Nutrition). Genetically similar (≤18 SNPs) Salmonella isolates were identified among several serovars isolated years apart. Almond isolates of Salmonella Montevideo (2001 to 2013) and Salmonella Newport (2003 to 2010) differed by ≤9 SNPs. Salmonella Enteritidis PT 30 isolated between 2001 and 2013 from survey, orchard, outbreak, and clinical samples differed by ≤18 SNPs. One to seven plasmids were found in 106 (62%) of the Salmonella isolates. Of the 27 plasmid families that were identified, IncFII and IncFIB plasmids were the most predominant. AMR genes were identified in 16 (9%) of the survey isolates and were plasmid encoded in 11 of 16 cases; 12 isolates (7%) had putative resistance to at least one antibiotic in three or more drug classes. A total of 303 virulence genes were detected among the assembled genomes; a plasmid that harbored a combination of pef, rck, and spv virulence genes was identified in 23% of the isolates. These data provide evidence of long-term survival (years) of Salmonella in agricultural environments.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/1932-6203Test

الوصول الحر: https://doaj.org/article/75dc535270b04cac91408e02fca22a7bTest