We conducted microbiological characterization and secondary analysis of longitudinal prospective data to understand the species distribution of vancomycin-resistant Enterococcus faecalis and Enterococcus faecium (VRE) and association with methicillin-resistant Staphylococcus aureus (MRSA) in patient and environmental samples collected in post-acute care, an important but little studied healthcare setting. Multisite longitudinal screening of 197 patients and their immediate environment in three Veterans Affairs Community Living Centers. Species-level identification of sample MRSA and VRE isolates. Measures of association and potential risk factors were evaluated using univariable and multivariable logistic regression at the isolate, visit, and patient level separately for patient and environmental contamination. A total of 689 VRE isolates were identified to the species level from 122 patients and their rooms. The ratio of E. faecium versus E. faecalis colonization and contamination differed significantly across the three facilities (6.0, 11.7 and 0.85, respectively, p < 0.001). In addition to antibiotic use, facility of stay was a significant independent risk factor for E. faecium colonization and contamination. Co-colonization and co-contamination with MRSA were higher-than-expected and significantly different by species (35.5

Soilless substrates used in hydroponic lettuce systems may differentially support the persistence of human pathogens. This study evaluated the impact of soilless substrate type with and without plants on the persistence of Salmonella and Listeria monocytogenes in an indoor hydroponic lettuce production system over 14 days. On day 0, rockwool (RW), low-density foam (LDF), peat moss (PM), and coco coir (CC) substrates in sub-irrigated nutrient solution were inoculated with Salmonella or L. monocytogenes cocktail at an initial concentration of ~6 log colony forming units (CFU) per milliliter. Treatments included planted and non-planted substrates in a factorial randomized complete block design with three biological replicates. Samples were collected on days 0, 3, 5, 7,10, and 14. Samples were processed, and bacteria were enumerated on selective media. A generalized linear mixed model with negative binomial distribution was used to assess the effect of planting status, substrate type, bacteria type, and their interactions, with nutrient solution temperature, pH, and electrical conductivity as covariates. Bacteria concentration (log₁₀ CFU/substrate) reduced significantly over time (p < 0.001). Substrate type had a substantial effect on pathogens, with higher concentrations in CC compared to the other substrate types (p < 0.001). L. monocytogenes and Salmonella also show distinct persistence patterns (p < 0.001). Significant interactions (p < 0.001) were observed between substrate type and bacteria type; and substrate type and planting status, indicating differential persistence dynamics across substrates over time under controlled indoor conditions for hydroponic lettuce production.

Human intestinal enteroid (HIE) and zebrafish larva (ZF) models support the replication of certain strains of human norovirus (HuNoV), the leading cause of viral gastroenteritis worldwide. The replication of 17 HuNoV-positive stool specimens (nine genotypes) from patients ranging from 5 months to 83 years old was evaluated in both HIE and ZF models. The yolk of 3-day post-fertilization ZF larvae was microinjected with 3 nL 10% clarified stool suspension. Each day post-infection (dpi), 10 larvae were pooled as one sample, and two specimens were collected daily until 5 dpi. Viral RNA was extracted from harvested larvae and quantified using reverse transcription (RT) droplet digital PCR. For the HIE model, J4FUT2 K1 enteroid monolayers were inoculated with 100-fold dilution of each stool specimen. Viral RNA levels were quantified at 1 and 72 h post-infection using RT real-time PCR. All genogroup (G) I specimens (n = 5) replicated in both models showing a 1-2.5 log increase in HuNoV RNA. Of the 12 GII specimens tested, 8 replicated in the ZF model, and 7 replicated in the HIE model. Specimens that failed to replicate in each model were not the same, although most of them were GII.4 Sydney [P16]. One additional strain, GII.17[P17], replicated only in the ZF model. Across GII strains, viral RNA increases ranged from 1.6 to 3.3 log in the ZF model and from 0.4 to 3.68 log in the HIE model. These data highlight variability in HuNoV replication efficiency across models, potentially indicating the influence of model-specific factors on replication.IMPORTANCEHuman intestinal enteroid and zebrafish larva models have been independently shown to support replication of different strains of human norovirus (HuNoV), the leading cause of viral gastroenteritis worldwide. However, whether the same HuNoV-positive stool specimens replicate similarly in both systems has not been examined. In this study, stool specimens positive for a range of HuNoV genotypes were tested in both models. While specimens from the genogroup I (GI) genogroup consistently replicated in both systems, specimens from the GII genogroup showed variable replication, with some replicating in only one model and a couple of specimens not replicating in either model. These findings demonstrate that model-specific biological factors influence HuNoV replication and highlight the significance of using complementary model systems to better understand HuNoV pathogenesis.

Ensuring food safety in produce packinghouses is vital for preventing foodborne illnesses and safeguarding public health. This study identifies cleaning and sanitation challenges within packinghouse environments through thematic analysis of interviews with produce safety educators (N = 21) and packinghouse operators (N = 15). Key challenges include resource limitations, knowledge gaps, outdated equipment, language barriers, and reluctance to invest in change. Small-scale growers often struggle with access to essential tools and supplies, while others may lack foundational knowledge regarding proper cleaning and sanitizing techniques. High employee turnover further complicates consistent training efforts. Language barriers hinder effective communication, particularly among non-English speaking workers and growers. In addition, reluctance or even the inability to invest in change can obstruct the adoption of improved practices. The study highlights specific contamination risks linked with common food-contact surfaces, such as wood, plastic, and stainless steel along with foam rollers, brushes, and rubber surfaces. Cleaning practices vary significantly, ranging from power washing and alcohol wipes to scrubbing with dish soap and steam cleaning. Sanitizers including chlorine, quaternary ammonium compounds, and peroxyacetic acid are frequently employed. Verification of cleaning effectiveness often relies on visual inspection rather than standardized methods such as environmental monitoring or Adenosine Triphosphate (ATP) testing. Recommendations based on these findings include developing clear, accessible training materials, enhancing communication for consistent messaging regarding cleaning and sanitation practices, and investing in research for more effective cleaning technologies and durable food-contact surfaces.

Enveloped and non-enveloped virus transmission can occur via person-to-person contact and potentially through contaminated surfaces with human hands. Establishing the efficacy of hand sanitizers, including gel and foam formats, is crucial in reducing the transmission of viruses of human health concern, yet foam hand sanitizers are generally underexplored despite being widely used. Following American Society for Testing and Materials (ASTM) E1052-20, the efficacy of foam-based hand sanitizers—one non-alcohol-based hand sanitizer and four alcohol-based hand sanitizers with benzalkonium chloride and ethanol as active ingredients, respectively—were explored using bacteriophage phi6 (Φ6) as a surrogate for enveloped viruses and bacteriophage MS2 (Emesvirus zinderi) and Tulane virus (TuV) as surrogates for non-enveloped viruses. Significant differences in log reduction were observed among viruses (P ≤ 0.05). After a 10 s exposure, a 5.23 ± 1.64 log reduction was observed for Φ6 while MS2 remained resistant (0.04 ± 0.08 log10 reduction). Conversely, significant log reductions (P ≤ 0.05) were observed for TuV across all foam-based hand sanitizer products ranging from 0.07 ± 0.1 to 1.09 ± 0.22. An exposure time of 10 s (i.e., the typical rubbing time in real-world scenarios following hand sanitizer application) is likely sufficient for enveloped virus inactivation based on the inactivation of bacteriophage Φ6 by the tested commercially available products. However, longer exposure times or different hand sanitizer formulations may be required to achieve similar log reductions against non-enveloped viruses such as human norovirus based on the surrogates (MS2, TuV) tested.

ABSTRACT Effective hand hygiene, such as hand washing and hand sanitizer use, is crucial in reducing infectious disease transmission via the hands. The efficacy of hand washing has been well-documented; however, relatively less is known regarding foam-based hand sanitizer efficacy, which is considered an effective alternative to washing hands with soap and water. Hand sanitizers are recommended by both the United States Centers for Disease Control and Prevention and the World Health Organization when the hands are not visibly dirty or greasy. This study examined the efficacy of five commercially available foam hand sanitizers—four alcohol-based and one non-alcohol-based—against enveloped and non-enveloped viruses using bacteriophage phi6 (Φ6) and bacteriophage MS2 as surrogates, respectively. A cocktail of MS2 and Φ6 (8 log PFU/mL) was inoculated on the hands and exposed to 3 or 6 mL of hand sanitizer product followed by rubbing the palmar surface of the hands together for 10 s or until dry. The results showed significant log reduction among the virus surrogates ( P ≤ 0.05), with Φ6 consistently showing higher susceptibility across all factors compared with MS2 with log reductions of 2.83 ± 1.98 and 0.50 ± 0.53 log reduction, respectively. Although dosing volume did not significantly impact log reduction ( P = 0.31), rubbing time significantly affected bacteriophage inactivation ( P ≤ 0.05). Higher log reduction was observed when hands were rubbed until dry (2.69 ± 2.06), compared with the typical 10 s rubbing time (0.65 ± 0.75). This study revealed that the efficacy of commercially available foam hand sanitizers depends on rubbing time and overall product formulation, rather than exclusively on active ingredient concentration. IMPORTANCE Human hands are a key factor in the transmission of viral diseases, and proper hand hygiene is regarded as the gold standard against the spread of such diseases. This study examined the effectiveness of a hand hygiene technique, that is, the application of foam-based hand sanitizers, against the inactivation of enveloped and non-enveloped virus surrogates on the hands. Factors such as virus type, rubbing time, volume of product used, and product formulation can significantly influence the efficacy of hand sanitizers. To assess these effects, we tested different rubbing times and product volumes across alcohol- and non-alcohol-based, foam hand sanitizer formulations, each with varying active ingredient concentrations and inactive ingredients. The study was performed on the palmar surface of human hands to realistically simulate real-world conditions, providing valuable evidence to inform future hand sanitizer practices aimed at maximizing the reduction of infectious viral pathogens on the hands.

The persistence and localization of Salmonella Javiana and Listeria monocytogenes in recirculating deep water culture (DWC) hydroponic systems during lettuce production were investigated. Recirculating DWC systems containing modified Hoagland's nutrient solution (NS) were utilized. The NS reservoirs of DWC systems containing 25-day old butterhead lettuce (cv. Rex) seedlings were inoculated separately with 6 log CFU/mL of S. Javiana or rifampicin resistant L. monocytogenes. Pathogens were enumerated in NS, rockwool + roots, roots, and leaves post inoculation from day 0 (lettuce seedling) to day 21 (mature lettuce head) via culture on selective media. Four experimental trials were completed for each pathogen with 2 treated and 2 control systems in each trial. Temperature, pH, and electrical conductivity data were collected and considered covariates during Analysis of Covariance (ANCOVA). The data were analyzed using a mixed model to compare mean log bacteria concentration by pathogen type based on sample type and sampling day followed by calculation of least-squares means where values were compared with Tukey-Kramer honest significant difference test at P = 0.05. A two-way interaction between sampling day and sample type (P < 0.0001) had a significant effect on S. Javiana and L.monocytogenes concentrations. The ANCOVA indicated that the interaction effect of NS pH and sample type had a significant effect on S. Javiana (P = 0.0054) and L. monocytogenes (P < 0.0001) concentrations. Salmonella Javiana and L.monocytogenes persisted in roots, rockwool + roots, and NS throughout the 21-day sampling period. No pathogens were detected in the edible portion of the lettuce. This study indicates that human pathogens can survive until harvest in DWC hydroponics systems used for lettuce production.

Nursing home (NH) residents in the United States routinely attend interactive visits for services such as therapy or dialysis, creating opportunities for pathogen transmission. A paucity of studies exist which delineate spread of pathogens beyond residents' in-room environment. In this prospective cohort study, we recruited 197 newly-admitted residents across three Veterans Affairs NHs to characterize multidrug-resistant organism (MDRO) prevalence, acquisition, and transmission. Participant hands, nares, groin, and seven environmental surfaces were swabbed during 758 regularly scheduled in-room visits; participant hands, healthcare personnel hands, and equipment were swabbed during 345 unscheduled interactive visits. We demonstrate that baseline MDRO colonization and new acquisition is common, and one in six interactive visits result in MDRO transmission. Whole genome sequencing on a subset of participants enabled us to identify sources of transmission where it was unknown using microbiologic methods alone. Our results illustrate MDRO transmission pathways and highlight the need for innovative, multidisciplinary interventions.

Chemical sanitizers are applied to food processing surfaces to inactivate bacterial pathogens. Pathogen type, surface type along with sanitizer type, concentration, and contact time are important factors potentially impacting sanitation efficacy. Numerous studies on chemical agents and lab-generated biofilms have been published; however, cross-study comparisons can be difficult. A systematic literature review (SLR) and meta-analysis were conducted to evaluate chemical sanitizer efficacy against Listeria monocytogenes, Salmonella spp., and Shiga toxin-producing Escherichia coli (STEC) within lab-generated biofilms on food contact surfaces (FCSs). The SLR included 13 peer-reviewed articles published between 2000 and 2020. Sanitizer concentration, type, contact time, surface type, and bacteria type were explored using multilevel mixed effects models to determine their impact on bacterial log reduction on FCS. The overall estimated log reduction was 2.90 (effect size [ES]) with a 95% CI = 2.40, 3.39 (p < 0.0001). The multilevel mixed effects model estimated log reductions of 2.67-3.82 for peracetic acid (PAA), quaternary ammonium compounds, sodium hypochlorite, hydrogen peroxide + PAA, and calcium hypochlorite, with significant differences across sanitizers. No significant differences were found between L. monocytogenes and STEC; however, both pathogens were significantly different from Salmonella spp. All pathogens were significant predictors of mean log reduction (p < 0.0001). No significant differences were found between surface types, while all were significant predictors of mean log reduction (p < 0.0001). Neither sanitizer concentration (p = 0.5554) nor sanitizer contact time (p = 0.1800) were found to be significant predictors of estimated mean log reduction. These findings highlight the importance of specific sanitizers and tailored approaches based on surface types and pathogen considerations.

The transmission and infection of enteric viruses can be influenced by co-existing bacteria within the environment and host. However, the viral binding ligands on bacteria and the underlying interaction mechanisms remain unclear. This study characterized the association of norovirus surrogate Tulane virus (TuV) and murine norovirus (MNV) as well as the human enteric virus Aichi virus (AiV) with six bacteria strains (Pantoea agglomerans, Pantoea ananatis, Bacillus cereus, Enterobacter cloacae, Exiguobacterium sibiricum, Pseudomonas spp.). At room temperature, the viruses bound to all bacteria in strain-dependent rates and remained bound for at least 2 h. The virus association with two gram-positive bacteria B. cereus and E. sibiricum was less efficient than gram-negative bacteria. Next, the bacterial envelope components including lipopolysaccharides (LPS), extracellular polymeric substances (EPS), and peptidoglycan (PG) from selected strains were co-incubated with viruses to evaluate their effect on virus infectivity. All the tested bacteria components significantly increased virus infection to variable degrees as compared to PBS. The LPS of E. coli O111:B4 resulted in the greatest increases of infection by 0.19 log PFU for TuV as determined by plaque assay. Lastly, bacterial whole cell lysate of B. cereus and E. cloacae was examined for their impact on the infectivity of MNV and TuV. The co-incubation with whole cell lysates significantly increased the infectivity of TuV by 0.2 log PFU but not MNV. This study indicated that both the individual bacteria components and whole bacterial cell lysate can enhance virus infectivity, providing key insights for understanding virus–bacteria interaction.

3D food printers (3DFPs) allow for the customization of physicochemical properties of foods in new ways. Storage conditions for food ink capsules and printed food inks have not been investigated. This study aimed to determine the impact of storage temperature, time, and method (pre- vs. postprinting) on Salmonella enterica and Listeria monocytogenes. A bacterial cocktail was cultured in minimal media and added to a protein cookie food ink at similar to 6.5 log CFU/g. The inoculated food ink was divided into 18 capsules (50 g/capsule); half were 3D printed. The remaining capsules and printed products were stored at three temperatures [20 degrees C, 4 degrees C, -18 degrees C]. Selective media (XLT-4 and CHROMagar Listeria) were used for pathogen enumeration. Aerobic plate count and yeast counts were performed at each time point. The pH and water activity (a(w)) of the food ink were measured at the initial and final timepoints. A significant four-way interaction effect was observed between microorganism type (L. monocytogenes/Salmonella), time, temperature, and storage method (capsule/print) (p = 0.014). Significant findings include (1) at -18 degrees C, concentrations of L. monocytogenes decreased between Day 0 and Day 1, (2) at 20 degrees C, concentrations of S. enterica were significantly higher in the capsule than in the printed food on Day 1 (p < 0.0001), and (3) at 4 degrees C, concentrations of S. enterica were significantly higher in the printed food on Day 5 compared to Day 1 (p < 0.0001) with a 0.9 (95% CI: 0.89, 0.91) log increase. In addition, a significant three-way interaction effect was found between microorganism type (yeast/aerobic counts), time, and temperature (p = 0.024). Yeast counts remained steady at all temperatures, while aerobic counts increased at 4 degrees C. Minimal differences were observed between Listeria and Salmonella and their responses to varying storage conditions over time indicating that storage method and temperature may be less important for a low-water activity product such as protein cookie food ink.

Surfaces contaminated with enveloped viruses, such as severe acute respiratory syndrome coronavirus 2 and influenza virus, can potentially spread illness via hand contact. Often, the efficacy of hand hygiene interventions relies on virus recovery from hands. However, the recovery of bacteriophage phi6 (Φ6), a recommended surrogate for enveloped viruses, from the entire hands using the ASTM E2011-21 standard has not been optimized. For Φ6 recovery from the hands, three eluents [lysogeny broth (LC), tryptic soy broth (TSB), and 1.5% beef extract (BE)] and three recovery methods [glove juice method (GJM), hand rinsing, and modified dish method] were examined. The effects of inoculum application on either the palmar surface or the whole hand were compared, and virus recovery was assessed under wet and dry conditions to identify the optimal combinations for maximizing Φ6 recovery. Statistical differences among methods, inoculum application, and recovery types were identified. While no statistical difference was observed among the eluents ( P = 0.281), LC demonstrated the highest Φ6 recovery efficiency, while TSB and BE had comparable recoveries. Two-way interaction effects were observed between method type vs. application type ( P ≤ 0.05), method type vs. recovery type ( P ≤ 0.05), and application type vs. recovery type ( P ≤ 0.05), indicating these factors influencing one another. Additionally, no Φ6 recovery was obtained for the dry basis recovery type and the GJM method type. Based on the present study, to maximize Φ6 recovery from the hands during hand hygiene studies, inoculum should be applied to the palmar surface and recovered while it is still wet using LC.

Surface sampling devices ranging in material composition and size can be used in environmental monitoring programs. This study aimed to compare the bacterial recovery efficiency of surface samplers on stainless steel (SS) and polypropylene (PP) surfaces. Separate cocktails of Listeria monocytogenes and Salmonella enterica strains were spot inoculated (1 mL; 40 spots × 25 μL) on SS and PP surfaces at high (7 log) and low (4 log) concentrations. A cellulose sponge sampler, polyurethane foam sponge sampler, and polyolefin nonwoven fabric sampler were utilized for bacteria recovery from SS and PP surfaces at two surface areas: 1× [929 cm2 (144 in2)] and 2× [1858 cm2 (288 in2)]. The effect of prewet volume (5 mL, 10 mL) on bacteria recovery from PP and SS was also investigated with the nonwoven fabric sampler at high inoculum level and 1× surface area. Three experimental trials were conducted totaling 336 samples, and recovery percentages were based on the CFU recovered divided by the initial CFU added to each surface. Statistical analysis was performed to determine whether sampler type, pathogen type, inoculum concentration, surface type, and surface area were significant predictors of recovery percentage. A significant five-way interaction (P = 0.0015) was observed between the predictor variables; therefore, no conclusions can be made regarding the main effects. The recovery percentage of L. monocytogenes was significantly higher than Salmonella from PP surfaces across all three sampler types. For the nonwoven fabric sampler, the 5 mL prewet volume yielded significantly higher recovery (P ≤ 0.05) for both bacteria combined at 10.66% (95% CI: 9.93, 11.44) compared to 3.09% (95% CI: 2.71, 3.52) recovery with the 10 mL prewet volume. However, the effect of volume on recovery depended on the interaction between surface type and inoculum level.

Background: The COVID-19 pandemic significantly affected high school students. Little is known about the mediators of student perceptions of infection prevention and public health entities. We piloted a survey to evaluate the relationship between student perceptions of COVID-19 topics and satisfaction with their most recent health class. Methods: Students from one private high school in southeast Michigan completed a survey in early 2022. The primary outcomes were 4 domains: vaccination knowledge, intervention effectiveness, intervention impact, and willingness to readopt an intervention. We assessed the associations between health class satisfaction and these outcomes using multiple linear regression. Results: One-hundred ninety students reported their health class satisfaction and were eligible for analysis. Students reported high confidence in vaccines (93%) but limited knowledge of COVID-19 vaccination (45%). Students perceived COVID-19 interventions as highly effective (range, 72% [hand hygiene]-93% [vaccination]) and reported a willingness to readopt them (range, 73% [stay-at-home orders]-96% [vaccination]). Health class satisfaction (54%) was positively associated with composite scores on vaccination knowledge and intervention effectiveness. Discussion: Assessing students' intrapandemic perspectives on infection prevention illuminated areas of strength (ie, intervention confidence) and areas for improvement (ie, intervention knowledge and institutional confidence). Conclusions: Students reported favorable perceptions regarding common infection prevention interventions. Future work should investigate the role of educational satisfaction in mediating confidence in public health interventions and institutions. (c) 2024 The Author(s). Published by Elsevier Inc. on behalf of Association for Professionals in Infection Control and Epidemiology, Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

OBJECTIVE:Patient hands' contribution to disease transmission in healthcare settings is an important, understudied topic. We assessed correlation between patient functional dependence and hand contamination with multi-drug resistant organisms (MDROs) in acute-care settings. DESIGN, SETTING, AND PATIENTS:Secondary, cross-sectional analyses of 399 general medicine patients enrolled in two tertiary-care hospitals over a six-month period. Our predictor was patient functional status evaluated using Katz Activities of Daily Living scale, scored as follows: functionally independent (scored 0), moderately dependent (score 1-3), and severely dependent (score of 4 or more). Our outcome was patient hand contamination with MDROs, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus, and resistant gram-negative bacteria. RESULTS:Of 399 patients, 298 were functionally independent, 45 were moderately dependent, and 56 were severely dependent. Odds of MDRO hand contamination were 2.63 (95% CI, 1.21-5.72) times higher in the severely dependent category compared to the independent category. Patients with feeding dependence had the highest odds of hand contamination with MDROs (OR 4.76, 95% CI, 1.54-14.71), followed by continence, dressing, and toileting. In addition to patient colonization, environmental contamination with MRSA was associated with patient function, with odds 2.60 (95% CI, 1.16-5.82) times higher in severely dependent patients. CONCLUSIONS:Patients with severe functional dependence are more likely to harbor MDROs on their hands and less likely to be able to cleanse them independently. Functionally dependent patients have high room contamination with MDROs. Patient hand hygiene interventions in the hospital should target this high-risk group.

3D food printers facilitate novel customization of the physicochemical properties of food. This study aimed to investigate the impact of storage conditions on the inactivation of the human norovirus surrogate, Tulane virus (TuV), within 3D printed foods. TuV-inoculated protein cookie food ink (~4 log PFU/g) was distributed into 18 3D food printer capsules (50g each); half immediately underwent extrusion. Storage of the capsules and printed food products at 20°C (0, 6, 12, and 24h), 4°C (0, 1, 3, and 5d), and -18°C (0, 1, 3, and 5d) was completed before analysis for TuV via plaque assays in addition to aerobic plate count, yeast and mold counts, and pH and water activity (aw) measurements. A significant 3-way interaction effect was observed between time, temperature, and storage method (capsule/print) (p = 0.006). Significant findings include: (1) a greater reduction in virions was observed in capsules after 24h at 20°C and (2) a substantial reduction in virions at 4°C from day 0 to day 1 was observed, independent of storage method. Microbial indicators remained steady across temperatures, with storage temperature significantly impacting pH and aw. A significant two-way interaction effect (p = 0.006) was found between microorganism type (yeast/aerobic counts), and temperature. This research seeks to provide insights for the food industry and regulatory bodies in crafting guidelines for the safe storage and handling of 3D printed foods and inks.

This study evaluated the impact of different food residues on the recovery of Listeria monocytogenes and Salmonella Typhimurium from stainless steel surfaces. Food residues tested include lettuce rinsate, blended lettuce, low-fat milk, and whole milk for Listeria monocytogenes, and powdered infant formula, all-purpose flour, and whole milk dairy powder for Salmonella Typhimurium. Bacterial suspensions were inoculated on stainless steel surfaces with or without food residues and held for different time periods. Significant differences (P < 0.0001) in Salmonella Typhimurium recovery were observed between the no food residue control and all food residues over 24 hours. For Listeria monocytogenes, minimal variability in recovery was observed among food residue types, with significant differences from the no food residue control (P < 0.05) observed after 24 hours. The study also found that surface sampling can spread Listeria monocytogenes and Salmonella Typhimurium on stainless steel surfaces, suggesting that food residue type may affect microbial recovery during environmental monitoring.

Farmers markets offer an apparently easy way for small-scale or hobbyist food producers to sell fresh produce, meat, and poultry from their farms or dis­tribute value-added products, but they may be unaware of the foodborne illness risks associated with both fresh produce and derivative products, as well as of their local food safety requirements. Food guidance and rules vary from state to state and market to market, making it difficult for indi­viduals to navigate the various regulatory levels. Even if a local food producer is exempt from these rules due to their amount of sales, they will still benefit greatly from resources and educational tools that increase awareness and knowledge of food safety best practices. This review discusses current knowledge of and guidelines for food safety in farmers markets based on peer-reviewed and grey literature as well as published guidelines and recommendations. We examine facilities and supplies, regulatory measures, education and train­ing, and Good Farmers Market Practices as pre­ventive measures to enhance food safety in farmers markets, which are critical to local and regional food systems. Overall, we identified various barri­ers to implementing farmers market food safety standards and practices in this scoping review; removing these barriers will require the participa­tion of local regularity authorities, market managers, vendors, and consumers.

3D food printers facilitate novel customization of the physicochemical properties of food. This study aimed to investigate the impact of storage conditions on the inactivation of the human norovirus surrogate, Tulane virus (TuV), within 3D printed foods. TuV-inoculated protein cookie food ink (∽ 4 log PFU/g) was distributed into 18 3D food printer capsules (50 g each); half immediately underwent extrusion. Storage of the capsules and printed food products at 20 °C (0, 6, 12, and 24 h), 4 °C (0, 1, 3, and 5d), and − 18 °C (0, 1, 3, and 5d) was completed before analysis for TuV via plaque assays in addition to aerobic plate count, yeast and mold counts, and pH and water activity (aw) measurements. A significant 3-way interaction effect was observed between time, temperature, and storage method (capsule/print) (p = 0.006). Significant findings include: (1) A greater reduction in virions was observed in capsules after 24 h at 20 °C and (2) a substantial reduction in virions at 4 °C from day 0 to day 1 was observed, independent of storage method. Microbial indicators remained steady across temperatures, with storage temperature significantly impacting pH and aw. A significant two-way interaction effect (p = 0.006) was found between microorganism type (yeast/aerobic counts) and temperature. This research seeks to provide insights for the food industry and regulatory bodies in crafting guidelines for the safe storage and handling of 3D printed foods and inks.

The rapid advancement of three-dimensional (3D) printing (i.e., a type of additive manufacturing) technology has brought about significant advances in various industries, including the food industry. Among its many potential benefits, 3D food printing offers a promising solution to deliver products meeting the unique nutritional needs of diverse populations while also promoting sustainability within the food system. However, this is an emerging field, and there are several aspects to consider when planning for use of 3D food printing for large-scale food production. This comprehensive review explores the importance of food safety when using 3D printing to produce food products, including pathogens of concern, machine hygiene, and cleanability, as well as the role of macronutrients and storage conditions in microbial risks. Furthermore, postprocessing factors such as packaging, transportation, and dispensing of 3D-printed foods are discussed. Finally, this review delves into barriers of implementation of 3D food printers and presents both the limitations and opportunities of 3D food printing technology.