Inactivation of Listeria monocytogenes and Salmonella spp. During Cooking of Country Ham and Fate of L. monocytogenes and Staphylococcus aureus During Storage of Country Ham Slices.

Thermal inactivation studies were undertaken on Listeria monocytogenes and Salmonella spp. inoculated on the surface of country ham. Hams (average = ca. 3.4 ± 0.5 kg each; average = ca. ≥18% shrinkage) were used as provided by the processor (i.e., "salted hams"), desalted in tap water (i.e., "desalted hams"), or dried for an additional period (i.e., "extra-dried hams"). Hams were surface inoculated (ca. 9.5 log CFU/ham) with a multistrain cocktail of L. monocytogenes or Salmonella spp. and cooked within a bag ina circulating water bath to an internal temperature of 130°F (54.4°C) instantaneous, 145°F (62.8°C) and held for 4 min, 153°F (67.2°C) and held for 34 s, or 160°F (71.1°C) instantaneous. Regardless of ham type, all four time and temperature combinations tested herein delivered a ≥6.7-log reduction of cells of L. monocytogenes or Salmonella spp. Differences in product pH, moisture content, or aw did not have an appreciable impact on the thermal inactivation of L. monocytogenes or Salmonella spp. on country ham. In addition, shelf-life studies were undertaken using slices of "salted" country ham that were surface inoculated (ca. 5.5 log CFU/slice) with a multistrain cocktail of L. monocytogenes or Staphylococcus aureus and then stored at 20°C. Levels of S. aureus increased by ca. ≤1.4 log CFU/slice during storage for 90 days, whereas levels of L. monocytogenes remained relatively unchanged (≤0.2 log CFU/slice increase). Our data validated that cooking parameters elaborated in the U.S. Department of Agriculture's Food Safety and Inspection Service Cooking Guideline for Meat and Poultry Products (Revised Appendix A) are sufficient to deliver significant reductions (ca. ≥6.8 log CFU/ham) in levels of L.monocytogenes and Salmonella spp. on country ham. In addition, in the event of postprocessing contamination, country ham may support the outgrowth of S. aureus or survival of L. monocytogenes during storage at 20°C for 90 days.

Minimum Concentrations of Slow Pyrolysis Paper and Walnut Hull Cyclone Biochars Needed to Inactivate Escherichia coli O157:H7 in Soil.

Antimicrobial properties of biochar have been attributed to its ability to inactivate foodborne pathogens in soil, to varying degrees. High concentrations of biochar have reduced E. coli O157:H7 in soil and dairy manure compost, based on alkaline pH. Preliminary studies evaluating 31 different biochars determined that two slow pyrolysis biochars (paper biochar and walnut hull cyclone biochar) were the most effective at inactivating E. coli in soil. A study was conducted to determine the lowest percentages of paper and walnut hull cyclone biochars needed to reduce E. coli O157:H7 in soil. A model soil was adjusted to 17.75% moisture, and the two types of biochar were added at concentrations of 1.0, 1.5, 2.0, 2.5, 3.5, 4.5, 5.5, and 6.5%. Nontoxigenic E. coli O157:H7 were inoculated into soil at 6.84 log CFU/g and stored for up to 6 weeks at 21°C. Mean E. coli O157:H7 counts were 6.01-6.86 log CFU/g at all weeks between 1 and 6 in soil-only positive control samples. Populations in all soil amended with 1.0 and 1.5% of either type of biochar (as well as 2.0% of the walnut hull biochar) resulted in ≤0.68 log reductions at week 6, when compared with positive controls. All other concentrations (i.e., ≥2.0% paper and ≥2.5% walnut hull) inactivated ≥2.7 log at all weeks between 1 and 6 (p < 0.05). At the end of 6 weeks, E. coli O157:H7 declined by 2.84 log in 2.0% paper biochar samples, while concentrations of between 2.5 and 6.5% paper biochar completely inactivated E. coli O157:H7, as determined by spiral plating, at weeks 5 and 6. In contrast, 2.0% walnut hull biochar lowered populations by only 0.38 log at week 6, although 2.5-6.5% concentrations of walnut hull biochar resulted in complete inactivation at all weeks between 3 and 6, as assessed by spiral plating. In summary, ≥2.5% paper or walnut hull biochar reduced ≥5.0 log of E. coli O157:H7 during the 6-week storage period, which we attribute to high soil alkalinity. Amended at a 2.5% concentration, the pH of soil with paper or walnut hull biochar was 10.67 and 10.06, respectively. Results from this study may assist growers in the use of alkaline biochar for inactivating E. coli O157:H7 in soil.

Large Iodine Variability in Retail Cows' Milk in the U.S.: A Follow-Up Study among Different Retail Outlets.

In a previous study, large variability in iodine content was found among samples of store brand retail milk at a single time point in a sampling taken from 24 nationwide U.S. locations for the USDA FoodData Central database, but the sampling plan was not designed to detect differences among locations. This follow-up study was carried out to evaluate iodine levels in retail milk across the U.S. over time. Milk samples (2% fat) were collected bimonthly in fourteen locations for one year and analyzed in duplicate. Control materials were used to support accuracy of results and ensure precision across analytical batches. The overall mean and standard error (SE) for iodine concentration were 82.5 (7.0) µg/240 mL serving, which was comparable to the previous national mean [85.0 (5.5) µg/240 mL]. A similar wide range among individual samples was detected (27.9-282 µg/240 mL). For some locations, the mean iodine concentration differed significantly from others, and differed from the national average by amounts ranging from -47 µg to +37 µg per serving. The between-sample range within location was large for some (up to 229 µg/serving) and minimal for others (as little as 13.2 µg/serving). These findings suggest iodine intake from some retail milk supplies could be over- or underestimated relative to the national average, even if the national average is suitable for population-wide intake estimates.

Fate of Listeria monocytogenes, Salmonella spp., and Shiga Toxin-Producing Escherichia coli on Slices of an All-Beef Soppressata during Storage.

Cells of Listeria monocytogenes, Salmonella spp., or Shiga toxin-producing Escherichia coli (STEC) were inoculated (ca. 4.0 log CFU/slice) onto slices (ca. 4 g each slice) of an all-beef soppressata (ca. pH 5.05 and aw 0.85). The storage of vacuum-sealed slices of inoculated soppressata at 4 °C or 20 °C for 90 days resulted in reductions of all three pathogens by ca. 2.2 to 3.1 or ca. ≥3.3 log CFU/slice, respectively. When pathogen levels decreased to below detection (≤1.18 log CFU/slice) by direct plating, it was possible to recover each of the target pathogens by enrichment, albeit more frequently from slices stored at 4 °C (p < 0.05) compared to 20 °C. In summary, the slices of the commercially produced beef soppressata selected for this study did not provide a favorable environment for either survival or outgrowth of surface-inoculated cells of L. monocytogenes, Salmonella spp., or STEC during storage.

Viability of Listeria monocytogenes and Salmonella spp. on Slices of a German-Style Bologna Containing Blends of Organic Acid Salts During Storage at 4 or 12°C.

Viability of cells of Listeria monocytogenes or Salmonella spp. was quantified on slices of a German-style bologna manufactured by a local butcher to contain no added antimicrobials or to include 0.9% or 1.3% of a blend of potassium acetate and sodium diacetate (K-Ace) or 2.5% of a blend of potassium lactate and sodium diacetate (K-Lac) as ingredients. After slicing (ca. 7.1 cm L by 6.7 cm W, ca. 0.5 cm thick, ca. 22.4 g each), a single slice of bologna was placed into a nylon-polyethylene bag and surface inoculated with 250 µL per side of a five-strain mixture of either cells of L. monocytogenes or Salmonella spp. to achieve an initial level of ca. 3.5-4.0 log CFU/slice. The packages were vacuum-sealed and then stored at 4 or 12°C for 90 and 30 days, respectively. Without antimicrobials added to the formulation, L. monocytogenes numbers increased by ca. 5.4 and 6.0 log CFU/slice at both 4 and 12°C during the entire 90- and 30-day storage period, respectively. Likewise, levels of Salmonella also increased by ca. 6.0 log CFU/slice at 12°C in the absence of added antimicrobials; however, levels of this pathogen decreased by ca. 1.7 log CFU/slice after 90 days at 4°C. With the inclusion of 0.9% or 1.3% K-Ace or 2.5% K-Lac in the bologna formulation, levels of L. monocytogenes decreased by ca. ≤0.7 log CFU/slice after 90 days at 4°C, whereas levels of Salmonella decreased by ca. 1.6-2.3 log CFU/slice. After 30 days at 12°C, levels of L. monocytogenes increased by ca. ≤3.4 log CFU/slice on product containing 0.9% K-Ace or 2.5% K-Lac but remained relatively unchanged on slices formulated with 1.3% K-Ace. For Salmonella, in the presence of 0.9% or 1.3% K-Ace or 2.5% K-Lac, pathogen levels decreased by ca. ≤0.7 log CFU/slice at 12°C after 30 days. Our data validate that the inclusion of K-Ace (0.9% or 1.3%) or K-Lac (2.5%) as ingredients is effective for controlling L. monocytogenes and Salmonella on slices of bologna during refrigerated storage.

Molecular Analysis and Sex-specific Response of the Hepcidin Gene in Yellow Perch (Perca Flavescens) Following Lipopolysaccharide Challenge.

Hepcidin antimicrobial peptide (hamp) is active in teleosts against invading pathogens and plays important roles in the stress and immune responses of finfish. The response of hamp gene was studied in yellow perch (yp) (Perca flavescens) challenged with lipopolysaccharides to understand if this immunity response is sex-specifically different. The cloned hamp gene consists of an open-reading frame of 273 bp and encodes a deduced protein of 90 amino acids (a.a.), which includes a signal peptide of 24 a.a., a pro-domain of 40 a.a. and a mature peptide of 26 a.a. Yp hamp involves 8 cysteine residues with 4 disulfide bonds, and a protein with an internal alpha helix flanked with C- and N-terminal random coils was modeling predicted. RT-qPCR was used to analyze the relative abundances (RAs) of hamp mRNA in the livers of juvenile female and male yellow perch challenged with lipopolysaccharide. The expression levels of hamp were significantly elevated by 3 h (RA = 7.3) and then peaked by 6 h (RA = 29.4) post-treatment in females but the peak was delayed to 12 h (RA = 65.4) post-treatment in males. The peak mRNA level of challenged males was shown 7.6-fold higher than females. The post-treatment responses in both genders decreased to their lowest levels by 24 h and 48 h. Overall, female perch had an earlier but less-sensitive response to the lipopolysaccharide challenge than male.

Annual and Seasonal Changes in Parasitism Rates by Hadronotus Pennsylvanicus (Hymenoptera: Scelionidae) on the Squash Bug Anasa Tristis (Hemiptera: Coreidae) in Squash Fields: Implications for Augmentative Releases.

This study evaluated parasitism rates by Hadronotus pennsylvanicus (Ashmead) (Hymenoptera: Scelionidae) on the squash bug Anasa tristis DeGeer (Hemiptera: Coreidae) over a six-year period in squash fields in Maryland. From 2016-2021, 2226 wild squash bug egg masses were collected, 2180 (98.0%) A. tristis egg masses and 46 (2.0%) A. armigera egg masses. The mean (±SE) parasitism rate was 10.9 ± 0.16%. Yearly parasitism rates were significantly different with rates in 2017 and 2018 that were significantly lower than in 2019, 2020, and 2021. The significant difference in parasitism rates based on planting date was primarily due to the high parasitism rate observed in 2021. These results suggest that the use of augmentative releases early in the season could result in effective control by increasing parasitism earlier in the season and by causing the parasitism rate in the field to peak at a higher number late in the season.

Viability of Shiga Toxin-Producing Escherichia coli, Salmonella spp., and Listeria monocytogenes during Preparation and Storage of Fuet, a Traditional Dry-Cured Spanish Pork Sausage.

ABSTRACT: The primary objective of this study was to monitor viability of Shiga toxin-producing Escherichia coli (STEC), Salmonella spp., and Listeria monocytogenes during preparation and storage of fuet. Regarding methodology, coarse-ground pork (ca. 35% fat) was mixed with salt (2.5%), dextrose (0.3%), starter culture (ca. 7.0 log CFU/g), celery powder (0.5%), and ground black pepper (0.3%) and then separately inoculated with a multistrain cocktail (ca. 7.0 log CFU/g) of each pathogen. The batter was stuffed into a ca. 42-mm natural swine casing and fermented at 23 ± 2°C and ca. 95% ± 4% relative humidity to ≤pH 5.3 (≤48 h). Sausages were then dried at 12 ± 2°C and ca. 80% ± 4% relative humidity to a water activity (aw) of 0.89 (within 33 days) or aw 0.86 (within 60 days). A portion of each batch of fuet was subjected to high-pressure processing (HPP; 600 MPa for 3 min) before chubs were vacuum packaged and stored for 30 days at 20 ± 2°C. The results revealed that pathogen numbers remained relatively unchanged after fermentation (≤0.35 log CFU/g reduction), whereas reductions of ca. 0.8 to 3.2 log CFU/g were achieved after drying fuet to aw 0.89 or 0.86. Regardless of whether fuet was or was not pressure treated, additional reductions of ca. 2.2 to ≥5.3 log CFU/g after drying were achieved following 30 days of storage at 20°C. For non-HPP-treated fuet dried to aw 0.89 and stored for 30 days at 20°C, total reductions of ≥5.3 log CFU/g in levels of STEC or Salmonella spp. were achieved, whereas levels of L. monocytogenes were reduced by ca. 3.6 log CFU/g. Total reductions of ≥5.3 log CFU/g in levels of all three pathogens were achieved after drying non-HPP-treated fuet to aw 0.86. For fuet dried to aw 0.89 or 0.86, that were pressure treated and then stored for 30 days at 20°C, total reductions of >6.2 log CFU/g in levels of all three pathogens were achieved. In conclusion, the processing parameters tested herein, with or without application of HPP, validated that reductions of ≥2.0 or ≥5.0 log CFU/g in levels of STEC, Salmonella spp., and L. monocytogenes were achieved during preparation and storage of fuet.

Spatial Heterogeneity of Sympatric Tick Species and Tick-Borne Pathogens Emphasizes the Need for Surveillance for Effective Tick Control.

Three tick species that can transmit pathogen causing disease are commonly found parasitizing people and animals in the mid-Atlantic United States: the blacklegged tick (Ixodes scapularis Say), the American dog tick (Dermacentor variabilis [Say]), and the lone star tick (Amblyomma americanum [L.]) (Acari: Ixodidae). The potential risk of pathogen transmission from tick bites acquired at schools in tick-endemic areas is a concern, as school-aged children are a high-risk group for tick-borne disease. Integrated pest management (IPM) is often required in school districts, and continued tick range expansion and population growth will likely necessitate IPM strategies to manage ticks on school grounds. However, an often-overlooked step of tick management is monitoring and assessment of local tick species assemblages to inform the selection of control methodologies. The purpose of this study was to evaluate tick species presence, abundance, and distribution and the prevalence of tick-borne pathogens in both questing ticks and those removed from rodent hosts on six school properties in Maryland. Overall, there was extensive heterogeneity in tick species dominance, abundance, and evenness across the field sites. A. americanum and I. scapularis were found on all sites in all years. Overall, A. americanum was the dominant tick species. D. variabilis was collected in limited numbers. Several pathogens were found in both questing ticks and those removed from rodent hosts, although prevalence of infection was not consistent between years. Borrelia burgdorferi, Ehrlichia chaffeensis, Ehrlichia ewingii, and Ehrlichia "Panola Mountain" were identified in questing ticks, and B. burgdorferi and Borrelia miyamotoi were detected in trapped Peromyscus spp. mice. B. burgdorferi was the dominant pathogen detected. The impact of tick diversity on IPM of ticks is discussed.

Parasitism and Predation on Sentinel Egg Masses of Three Stink Bug Species (Hemiptera: Pentatomidae) in Native and Exotic Ornamental Landscapes.

This study evaluated parasitism and predation on sentinel egg masses of three stink bug species, the spined soldier bug, Podisus maculiventris (Say), the brown stink bug, Euschistus servus (Say), and the invasive brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), in ornamental landscapes composed of either native or exotic plants. This study also compared the species composition of parasitoids attacking two native stink bug species (P. maculiventris and E. servus) with those attacking the invasive BMSB on the same tree species in the same habitat. Overall, egg parasitism and predation were much higher on the two native stink bug species compared with BMSB, with an average parasitism rate of 20.6% for E. servus, 12.7% for P. maculiventris, and only 4.2% for H. halys and an average predation rate of 8.2% for E. servus,17.7% for P. maculiventris, and 2.3% for H. halys. Egg predation was also significantly higher on P. maculiventris than on E. servus eggs. Eight parasitoid species attacked sentinel stink bug eggs in the ornamental landscaped plots. Trissolcus euschisti (Ashmead) (Hymenoptera: Scelionidae) was the predominant parasitoid for all three stink bug species. There were no significant differences in parasitism and predation rates on any of the stink bug species between native and exotic plots. Therefore, there is no evidence that ornamental landscapes composed of native plants increased parasitism or predation rates of sentinel egg masses of two native stink bug species or the invasive BMSB, compared with those composed entirely of exotic plants.

Temporal and Agricultural Factors Influence Escherichia coli Survival in Soil and Transfer to Cucumbers.

Biological soil amendments of animal origin (BSAAO) increase nutrient levels in soils to support the production of fruits and vegetables. BSAAOs may introduce or extend the survival of bacterial pathogens which can be transferred to fruits and vegetables to cause foodborne illness. Escherichia coli survival over 120 days in soil plots (3 m2) covered with (mulched) or without plastic mulch (not mulched), amended with either poultry litter, composted poultry litter, heat-treated poultry pellets, or chemical fertilizer, and transfer to cucumbers in 2 years (2018 and 2019) were evaluated. Plots were inoculated with E. coli (8.5 log CFU/m2) and planted with cucumber seedlings (Supremo). The number of days needed to reduce E. coli levels by 4 log CFU (dpi4log) was determined using a sigmoidal decline model. Random forest regression and one-way analysis of variance (ANOVA; P < 0.05) identified predictors (soil properties, nutrients, and weather factors) of dpi4log of E. coli and transfer to cucumbers. The combination of year, amendment, and mulch (25.0% increase in the mean square error [IncMSE]) and year (9.75% IncMSE) were the most prominent predictors of dpi4log and transfer to cucumbers, respectively. Nitrate levels at 30 days and soil moisture at 40 days were also impactful predictors of dpi4log. Differing rainfall amounts in 2018 (24.9 in.) and 2019 (12.6 in.) affected E. coli survival in soils and transfer to cucumbers. Salmonella spp. were recovered sporadically from various plots but were not recovered from cucumbers in either year. Greater transfer of E. coli to cucumbers was also shown to be partially dependent on dpi4log of E. coli in plots containing BSAAO.IMPORTANCE Poultry litter and other biological soil amendments are commonly used fertilizers in fruit and vegetable production and can introduce enteric pathogens such as Escherichia coli O157:H7 or Salmonella previously associated with outbreaks of illness linked to contaminated produce. E. coli survival duration in soils covered with plastic mulch or uncovered and containing poultry litter or heat-treated poultry litter pellets were evaluated. Nitrate levels on day 30 and moisture content in soils on day 40 on specific days were good predictors of E. coli survival in soils; however, the combination of year, amendment, and mulch type was a better predictor. Different cumulative rainfall totals from year to year most likely affected the transfer of E. coli from soils to cucumbers and survival durations in soil. E. coli survival in soils can be extended by the addition of several poultry litter-based soil amendments commonly used in organic production of fruits and vegetables and is highly dependent on temporal variation in rainfall.

Metagenomic Analysis of 16S Clostridium perfringens Amplicons Corroborates C. perfringens Counts on Select Agar and C. perfringens PCR Analyses of Bacteria in Broiler Farm Litter.

The purpose of this study was twofold-first, to determine whether analysis of bacterial 16S ribosomal RNA (rRNA) in poultry litter corroborated standard Clostridium perfringens counts and PCR assay, and second, to find whether a correlation between 16S rRNA analysis and netB or Tpel toxin PCR intensity with chick mortality existed. At three time points of growout (0, 2, and 4 wk) litter samples were collected from 23 broiler houses representing eight farms during a coccidiosis vaccine control program. DNA extracted from these samples was used for microbiota determination by sequencing the hypervariable V3-V4 region of bacterial 16s rRNA. Obtained sequences were analyzed by QIIME 2 and the Greengenes database for taxonomic composition and relative abundance of C. perfringens in the litter bacterial population. Clostridium perfringens counts on select agar and semiquantitative PCR for C. perfringens were compared with 16S analysis for equivalence testing. Relative abundance of C. perfringens estimated by 16S analysis and semiquantitative PCR for netB and Tpel toxin DNA were analyzed by Pearson linear correlation and statistical equivalence analyses with cumulative chick mortality at 4 and 9 wk growout. When data from all time points were combined, abundance estimates by C. perfringens 16S were statistically equivalent (α = 0.10) to both C. perfringens PCR and C. perfringens counts. Yet, no correlations were observed between any estimate of C. perfringens abundance and cumulative percent chick mortality at 4 or 9 wk growout. However, correlation analyses revealed a significant linear relationship between netB signal at 0 wk (r = 0.55) and 4 wk (r = 0.46) and cumulative mortality at 9 wk growout (P < 0.05). Similarly, abundance of Tpel at 0 and 2 wk showed a linear relationship with cumulative percent mortality at both 4 and 9 wk growout (0.44 ≤ r ≤ 0.54, P < 0.05). No correlations were observed between any other genera or species determined by 16S and cumulative percent chick mortality.

Ovipositional Behavior of the Egg Parasitoid Gryon pennsylvanicum (Hymenoptera: Scelionidae) on Two Squash Bug Species Anasa tristis (Hemiptera: Coreidae) and Anasa armigera: Effects of Parasitoid Density, Nutrition, and Host Egg Chorion on Parasitism Rates.

This study examined the ovipositional behavior of Gryon pennsylvanicum Ashmead (Hymenoptera: Scelionidae) on egg masses of two squash bug species Anasa tristis DeGeer and Anasa armigera Say (Hemiptera: Coreidae) by evaluating how parasitoid density and access to nutrition influenced percent parasitism on egg masses of different sizes in laboratory tests. When three parasitoids were exposed to A. tristis egg masses with only three to five eggs, 72.7% of parasitoids became trapped in the eggs and failed to emerge successfully. These results suggest that competition between larvae within the egg may have reduced the fitness of the surviving parasitoid. Continual access to honey water did not significantly influence parasitism rates on A. armigera egg masses and only increased parasitism on A. tristis egg masses with 20-25 eggs. Overall, parasitism rates were higher on A. armigera egg masses than on A. tristis egg masses, and parasitoids were more likely to emerge successfully from A. armigera eggs than from A. tristis eggs. Parasitoids spent the same amount of time probing eggs of the two species, but they spent significantly more time drilling into A. tristis eggs than A. armigera eggs. Measurements taken using transmission electron microscopy determined that the average combined width of the epicuticle and exocuticle of the egg chorion was significantly greater for A. tristis eggs than for A. armigera eggs. This difference may account for the lower rates of parasitism and parasitoid emergence and for the increased time spent drilling into A. tristis eggs compared with A. armigera eggs.

BMI Is Associated With Increased Plasma and Urine Appearance of Glucosinolate Metabolites After Consumption of Cooked Broccoli.

Introduction: Preclinical studies suggest that brassica vegetable diets decrease cancer risk, but epidemiological studies show varied effects, resulting in uncertainty about any health impact of brassicas. Factors controlling absorption of glucosinolate metabolites may relate to inconsistent results. We reported previously that subjects with BMI > 26 kg/m2 (HiBMI), given cooked broccoli plus raw daikon radish (as a source of plant myrosinase) daily for 17 days, had lower glucosinolate metabolite absorption than subjects given a single broccoli meal. This difference was not seen in subjects with BMI < 26 kg/m2 (LoBMI). Our objective in this current study was to determine whether a similar response occurred when cooked broccoli was consumed without a source of plant myrosinase. Methods: In a randomized crossover study (n = 18), subjects consumed no broccoli for 16 days or the same diet with 200 g of cooked broccoli daily for 15 days and 100 g of broccoli on day 16. On day 17, all subjects consumed 200 g of cooked broccoli. Plasma and urine were collected for 24 h and analyzed for glucosinolate metabolites by LC-MS. Results: There was no effect of diet alone or interaction of diet with BMI. However, absorption doubled in HiBMI subjects (AUC 219%, plasma mass of metabolites 202% compared to values for LoBMI subjects) and time to peak plasma metabolite values and 24-h urinary metabolites also increased, to 127 and 177% of LoBMI values, respectively. Conclusion: BMI impacts absorption and metabolism of glucosinolates from cooked broccoli, and this association must be further elucidated for more efficacious dietary recommendations. Clinical Trial Registration: This trial was registered at clinicaltrials.gov (NCT03013465).

Use of Flowering Plants to Enhance Parasitism and Predation Rates on Two Squash Bug Species Anasa tristis and Anasa armigera (Hemiptera: Coreidae).

A two-year study evaluated the effect of a flowering border of buckwheat Fagopyrum esculentum Moench on rates of egg parasitism, egg predation and adult parasitism on two squash bug species, Anasa tristis (DeGeer) and Anasa armigera Say, by comparing rates in squash fields with and without a flowering border. Furthermore, we evaluated whether there was an edge effect by comparing parasitism and predation rates in plots located in the corner of a squash field with plots located in the center of a squash field for fields with and without a flowering border. The egg parasitism rates were not affected by either treatment (flowering border or control) or plot location (edge or center). Anasa armigera egg masses only accounted for 4.3% of the total egg masses collected. The egg parasitism rates increased gradually throughout the season, peaking in the last week of August in 2017 at 45% for A. tristis egg masses. The most common egg parasitoid recovered was Gryon pennsylvanicum (Ashmead) followed by Ooencyrtus anasae (Ashmead). Adult parasitism was not affected by treatment, but A. tristis adult parasitism rates were higher in plots located on the edge of squash fields compared with plots located in the center of squash fields in 2016. Since adult parasitoid, Trichopoda pennipes (Fabricius) flies were observed visiting buckwheat flowers, future studies could explore the possibility that the flowering buckwheat may have a more impact on adult parasitism if there was a greater distance between fields with and without a flowering border.

Dynamic changes in the physicochemical properties of fresh-cut produce wash water as impacted by commodity type and processing conditions.

Organic materials in fresh-cut produce wash water deplete free chlorine that is required to prevent pathogen survival and cross-contamination. This research evaluated water quality parameters frequently used to describe organic load for their fitness to predict chlorine demand (CLD) and chemical oxygen demand (COD), which are major needs identified by the industry-led produce food safety taskforce. Batches of romaine lettuce, iceberg lettuce, or carrot of different cut sizes and shapes were washed in 40 liters of water. Physicochemical properties of wash water including CLD, COD, total organic carbon (TOC), total suspended solids (TSS), total dissolved solids (TDS), turbidity, total sugar content, and pH, were monitored. Results indicate that pH is primarily commodity dependent, while organic load is additionally impacted by cutting and washing conditions. Significant linear increases in COD, TOC, CLD, TDS, and turbidity resulted from increasing product-to-water ratio, and decreasing cut size. Physicochemical parameters, excluding pH, showed significant positive correlation across different cut sizes within a commodity. High correlations were obtained between CLD and COD and between COD and TOC for pooled products. The convenient measurement of TDS, along with its strong correlation with COD and CLD, suggests the potential of TDS for predicting organic load and chlorine reactivity. Finally, the potential application and limitation of the proposed models in practical produce processing procedures are discussed extensively.

Age-Associated Distribution of Antimicrobial-Resistant Salmonella enterica and Escherichia coli Isolated from Dairy Herds in Pennsylvania, 2013-2015.

Antimicrobial resistance has become a major global public health concern, and agricultural operations are often implicated as a source of resistant bacteria. This study characterized the prevalence of antimicrobial-resistant Salmonella enterica and Escherichia coli from a total of 443 manure composite samples from preweaned calves, postweaned calves, dry cows, and lactating cows from 80 dairy operations in Pennsylvania. A total of 1095 S. enterica and 2370 E. coli isolates were screened and tested for resistance to 14 antimicrobials on the National Antimicrobial Resistance Monitoring System Gram-negative (NARMS GN) panel. Salmonellae were isolated from 67% of dairy operations, and 99% of the isolates were pan-susceptible. Salmonella were isolated more frequently from lactating and dry cow samples than from pre- and postweaned calf samples. Overall, the most prevalent serotypes were Cerro, Montevideo, Kentucky, and Newport. E. coli were isolated from all the manure composite samples, and isolates were commonly resistant to tetracyclines, sulfonamides, and aminoglycosides. Resistance was detected more frequently in the E. coli isolates from pre- and postweaned calf samples than in isolates from dry and lactating cow samples (p < 0.05). Multidrug-resistant E. coli (i.e., resistant to >3 antimicrobial classes) were isolated from 66 farms (83%) with significantly greater prevalence in preweaned calves (p < 0.05) than in the older age groups. The blaCTX-M and blaCMY genes were detected in the cephalosporin-resistant E. coli from 4% and 35% of the farms, respectively. These findings indicate that dairy animals, especially the calf population, serve as significant reservoirs for antimicrobial-resistant bacteria. Additional research on the colonization and persistence of resistant E. coli in calves is warranted to identify potential avenues for mitigation.

Survival of Escherichia coli in Manure-Amended Soils Is Affected by Spatiotemporal, Agricultural, and Weather Factors in the Mid-Atlantic United States.

Untreated biological soil amendments of animal origin (BSAAO), such as manure, are commonly used to fertilize soils for growing fruit and vegetable crops and can contain enteric bacterial foodborne pathogens. Little is known about the comparative longitudinal survival of pathogens in agricultural fields containing different types of BSAAO, and field data may be useful to determine intervals between manure application and harvest of produce intended for human consumption to minimize foodborne illness. This study generated 324 survival profiles from 12 different field trials at three different sites (UMES, PA, and BARC) in the Mid-Atlantic United States from 2011 to 2015 of inoculated nonpathogenic Escherichia coli (gEc) and attenuated O157 E. coli (attO157) in soils which were unamended (UN) or amended with untreated poultry litter (PL), horse manure (HM), or dairy manure solids (DMS) or liquids (DML). Site, season, inoculum level (low/high), amendment type, management (organic/conventional), and depth (surface/tilled) all significantly (P < 0.0001) influenced survival duration (dpi100mort). Spatiotemporal factors (site, year, and season) in which the field trial was conducted influenced survival durations of gEc and attO157 to a greater extent than weather effects (average daily temperature and rainfall). Initial soil moisture content was the individual factor that accounted for the greatest percentage of variability in survival duration. PL supported greater survival durations of gEc and attO157, followed by HM, UN, and DMS in amended soils. The majority of survival profiles for gEc and attO157 which survived for more than 90 days came from a specific year (i.e., 2013). The effect of management and depth on dpi100mort were dependent on the amendment type evaluated.IMPORTANCE Current language in the Food Safety Modernization Act Produce Safety Rule states no objection to a 90- or 120-day interval between application of untreated BSAAO and harvest of crops to minimize transfer of pathogens to produce intended for human consumption with the intent to limit potential cases of foodborne illness. This regional multiple season, multiple location field trial determined survival durations of Escherichia coli in soils amended with manure to determine whether this interval is appropriate. Spatiotemporal factors influence survival durations of E. coli more than amendment type, total amount of E. coli present, organic or conventional soil management, and depth of manure application. Overall, these data show poultry litter may support extended survival of E. coli compared to horse manure or dairy manure, but spatiotemporal factors like site and season may have more influence than manure type in supporting survival of E. coli beyond 90 days in amended soils in the Mid-Atlantic United States.

Absorption and metabolism of isothiocyanates formed from broccoli glucosinolates: effects of BMI and daily consumption in a randomised clinical trial.

Sulphoraphane originates from glucoraphanin in broccoli and is associated with anti-cancer effects. A preclinical study suggested that daily consumption of broccoli may increase the production of sulphoraphane and sulphoraphane metabolites available for absorption. The objective of this study was to determine whether daily broccoli consumption alters the absorption and metabolism of isothiocyanates derived from broccoli glucosinolates. We conducted a randomised cross-over human study (n 18) balanced for BMI and glutathione S-transferase µ 1 (GSTM1) genotype in which subjects consumed a control diet with no broccoli (NB) for 16 d or the same diet with 200 g of cooked broccoli and 20 g of raw daikon radish daily for 15 d (daily broccoli, DB) and 100 g of broccoli and 10 g of daikon radish on day 16. On day 17, all subjects consumed a meal of 200 g of broccoli and 20 g of daikon radish. Plasma and urine were collected for 24 h and analysed for sulphoraphane and metabolites of sulphoraphane and erucin by triple quadrupole tandem MS. For subjects with BMI >26 kg/m2 (median), plasma AUC and urinary excretion rates of total metabolites were higher on the NB diet than on the DB diet, whereas for subjects with BMI <26 kg/m2, plasma AUC and urinary excretion rates were higher on the DB diet than on the NB diet. Daily consumption of broccoli interacted with BMI but not GSTM1 genotype to affect plasma concentrations and urinary excretion of glucosinolate-derived compounds believed to confer protection against cancer. This trial was registered as NCT02346812.

Comparative Study of Egg Parasitism by Gryon pennsylvanicum (Hymenoptera: Scelionidae) on Two Squash Bug Species Anasa tristis and Anasa armigera (Hemiptera: Coreidae).

This study evaluated how the size of the egg mass and the parasitoids prior exposure to eggs influenced parasitism rates by Gryon pennsylvanicum Ashmead (Hymenoptera: Scelionidae) on egg masses of two squash bug species, Anasa tristis DeGeer and Anasa armigera Say (Hemiptera: Coreidae). G. pennsylvanicum is the primary egg parasitoid of A. tristis. There were no published reports available on egg parasitism of A. armigera. In choice tests, there was no difference in host acceptance by G. pennsylvanicum of egg masses of the two squash bug species. In no-choice tests, overall parasitism rates were significantly higher on A. armigera egg masses than on A. tristis egg masses. Naive parasitoids had significantly higher parasitism rates than experienced parasitoids on egg masses of both squash bug species. In a comparison of parasitism rates of field-collected and laboratory-tested A. tristis egg masses of different sizes, parasitism rates were similar in the field and in the laboratory, with the exception of egg masses with > 25 eggs. Only 17.9% of eggs were parasitized in the laboratory, compared with 36.4% in the field. Results of this study indicate that transient egg limitation prevents G. pennsylvanicum from ovipositing in every available host egg in large squash bug egg masses. The low parasitism rate of G. pennsylvanicum on large egg masses may limit its effectiveness as a biological control agent of squash bugs.