With the increased consumption of fresh produce, a proportional increase in numbers of produce-related foodborne illness has been observed. An estimate of foodborne illness during 1998 to 2008 attributed ∼46% of the incidences to produce. Any foodborne illness associated with produce can have devastating consequences to the industry. The most recent data from the Centers for Disease Control and Prevention implicate leafy vegetables, vine-stalk vegetables, root vegetables, and sprouts as the most common cause of produce-related foodborne outbreaks. Excess rainfall or flooding, mainly by altering levels of soil moisture and oxygen content, affects the microbial community in soil. The goal of this research was to determine the survivability of a three-serovar Escherichia coli and a five-serovar Salmonella enterica cocktail in microcosms prepared with Candler sand (CS) and Orangeburg sandy loam (OSL) soils. Microcosms were prepared with low, medium, and high volumetric water contents and were incubated at 20 and 30°C. Serotyping was used to determine which E. coli or Salmonella serovar(s) from each cocktail persisted. Microcosm inoculation levels were ∼7.0 log CFU/g. Sampling for CS and OSL microcosms incubated at 20°C ended on day 364 and 357, respectively. The reduction of Salmonella and E. coli to below the limit of detection (extinction) in CS microcosms (incubated at 30°C at all volumetric water content [VWC] levels) was reached on day 168 and 56, respectively. Extinction of Salmonella and E. coli in OSL microcosms (incubated at 30°C at all VWCs) was reached on day 168 and 224, respectively. Of the Salmonella and E. coli serovars analyzed, Salmonella Javiana persisted the longest in both soil types, whereas E. coli O104:H4 and E. coli O145 persisted the longest in CS and OSL microcosms, respectively. Results from the current study suggest that soil type and temperature influenced pathogen persistence in CS and OSL soils more than moisture level and pathogen type.

For over a decade, Salmonella contamination has increasingly led to outbreaks of foodborne illness associated with fresh produce. The use of untreated animal manures, or biological soil amendments of animal origin (BSAAO), to amend agricultural soils holds a risk of contamination from foodborne pathogens, such as Salmonella . This study was conducted to determine the prevalence, concentration, serotypes, and antimicrobial resistance (AMR) profiles of Salmonella in poultry litter from Florida farms. Litter pH, total Kjeldahl nitrogen (TKN), total ammonia nitrogen (TAN), total phosphorus (P 2 O 5 ), total potassium (K 2 O), moisture content, total solids, total ash, organic matter, and aerobic plate count (APC) were also measured. Litter samples (n = 54) were collected from 18 broiler farms across three seasons (spring, summer, and winter). Salmonella concentrations were enumerated using a most probable number (MPN) method and antimicrobial susceptibility testing (AST) was performed. The prevalence of Salmonella in litter samples was 61.1%, with a geometric mean of 0.21 ± 20.7 MPN/g. Across all seasons, Salmonella concentrations were not influenced by the chemical, physical, or microbial properties measured. Recovered Salmonella isolates (n = 290) were grouped into serogroups O:4 (43.1%), O:7 (26.9%), O:8 (11.0%), O:1,3,10,19 (7.9%), and O:9,46 (7.2%). Serotyping select Salmonella isolates (n = 47) resulted in 12 serotypes, with the most common being Typhimurium (27.7%), Kentucky (17.0%), Enteritidis (14.9%), and Mbandaka (14.9%). Antimicrobial resistance to tetracycline (29.8%), sulfisoxazole (23.4%), and streptomycin (14.9%) was observed. No isolates were resistant to more than two antimicrobial agents. This study provides valuable information towards future risk assessments for the use of poultry litter as an untreated BSAAO.

An important consideration in virus contact transmission is the transfer rate between hands and surfaces, which is driven by several factors, including virus persistence on inanimate surfaces. This research characterized Φ6 persistence on surfaces commonly encountered in public settings based on various factors.

TGFβ signaling is associated with non-response to immune checkpoint blockade in patients with advanced cancers, particularly in the immune-excluded phenotype. While previous work demonstrates that converting tumors from excluded to inflamed phenotypes requires attenuation of PD-L1 and TGFβ signaling, the underlying cellular mechanisms remain unclear. Here, we show that TGFβ and PD-L1 restrain intratumoral stem cell-like CD8 T cell (TSCL) expansion and replacement of progenitor-exhausted and dysfunctional CD8 T cells with non-exhausted T effector cells in the EMT6 tumor model in female mice. Upon combined TGFβ/PD-L1 blockade IFNγhi CD8 T effector cells show enhanced motility and accumulate in the tumor. Ensuing IFNγ signaling transforms myeloid, stromal, and tumor niches to yield an immune-supportive ecosystem. Blocking IFNγ abolishes the anti-PD-L1/anti-TGFβ therapy efficacy. Our data suggest that TGFβ works with PD-L1 to prevent TSCL expansion and replacement of exhausted CD8 T cells, thereby maintaining the T cell compartment in a dysfunctional state.

Salmonella has been reported to be involved in several foodborne illness outbreaks, many of which resulted from consumption of raw tomatoes. This research aimed to optimize and evaluate the concentration of free chlorine (hypochlorous acid [HOCl]) used as a sanitizer to prevent cross-contamination of tomatoes inoculated with a cocktail of five rifampin-resistant Salmonella enterica serovars in a laboratory-based model flume system. Organic load, prepared using sterilized Scotts Premium Topsoil, was added in different quantities to the flume wash water to simulate real-world packinghouse conditions. In a typical packinghouse operation utilizing a recirculating flume system, the organic matter washed from tomato surfaces accumulates over time. In this study, different concentrations (0, 25, 50, 75, and 100 ppm) of HOCl were used as sanitizers under three organic load conditions (0, 650, and 1,000 mg/L chemical oxygen demand). Results showed that 100 ppm of HOCl was necessary to prevent Salmonella cross-contamination of uninoculated tomatoes in the model flume system in the presence of organic loading. Also, when treated with 100 ppm of HOCl, Salmonella levels were reduced by>4.5 log CFU per tomato from inoculated tomatoes in the presence of organic load. At 75 ppm of HOCl, Salmonella cross-contamination was prevented, but only in the absence of organic loading. In studies in which plate counts were negative, whole tomato enrichment studies were performed. No cross-contamination of uninoculated tomatoes was recorded when 100 ppm of HOCl was used, even in the presence of high organic load (1,000 mg/L chemical oxygen demand). Although sanitizer application reduces contamination on tomato surfaces, the primary function of sanitizers in the wash water is to prevent cross-contamination.

Florida peaches (Prunus persica) typically are picked and placed in a cold room on the day of harvest, then packed and shipped the next day. This room cooling (RC) is slow, requiring ≈24 hours or more for the fruit to reach optimal temperature (6 to 7 °C). There is currently limited research on the effect of cooling practices on microbial quality of peaches, yet this study is essential for decision making in areas such as upgrading packing house facilities and the implementation of improved handling procedures. This research compared the efficacies of postharvest cooling by RC, forced-air cooling (FAC), and hydrocooling with sanitizer (HS) treatment of peaches to reduce their surface microbial population and to determine the effect on shelf life and microbial quality. Three trials for RC and two trials each for FAC and HS were performed. Following cooling, fruit were stored at 1 °C. The average aerobic plate count (APC) from field samples was 5.29 log cfu/peach, which remained unchanged after RC or FAC but was reduced significantly (P < 0.05) to 4.63 log cfu/peach after HS. The average yeast and mold counts (Y&M) from field samples (6.21 log cfu/peach) were reduced highly significantly (P < 0.001) to 4.05 log cfu/peach after HS. Hydrocooling significantly (P < 0.05) reduced the APC and Y&M counts from the peaches and showed promise in maintaining the microbiological quality of the fruit throughout storage. However, at the end of the 21-day storage period, there was no significant difference in APC or Y&M counts from peaches, irrespective of the cooling methods. Peaches that went through the hydrocooling process and were subsequently packed showed an increase (P < 0.05) in both APC and Y&M counts, while fruit that were not hydrocooled showed no such increase. Information obtained will be used to recommend the best temperature management practices for maintaining the postharvest quality of peaches. A detailed cost-benefit analysis of different cooling methods and the time interval between harvest and shipment are both necessary for a more conclusive recommendation.

Poultry litter is a widely used biological soil amendment in the production of fresh produce. However, poultry litter may contain human pathogens, such as Salmonella , which introduces the risk of preharvest produce contamination in agricultural fields.

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