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Imported berries have contributed to U.S. hepatitis A virus (HAV) infections. Minimal processing by freeze-drying is preferred by industry for preserving food quality, but virus inactivation by this process may be limited. This study investigated HAV survival on strawberries during 24-h freeze-drying followed by 22°C storage. The outer surfaces of strawberry slices were prepared and each inoculated with 5 to 6 log PFU HAV, air dried for 20 min, frozen for 1 h at -80°C, and freeze-dried for 24 h with radiant heating up to 36°C. Infectious HAV levels eluted from berry slices were quantified on FRhK-4 cells grown onto six-well dishes. Freeze-drying trials (n = 17) with radiant heating inactivated ≤1 log PFU per trial, although HAV inactivation was significantly (P < 0.01) greater at 36°C than at 15°C heating. Average HAV reduction rate on dried berries continuously decreased as storage time increased: 0.2-, 0.09-, 0.08-, 0.04-, 0.04-, and 0.03-log reduction per day at day 2, 7, 14, 28, 42, and 56, respectively, with the cumulated log reduction divided by storage days. Therefore, the best-fit regression for the total or cumulative virus reduction (Y) at any given day (X) is Y = 0.2882X0.4503 (r2 = 0.97), with a maximum 2.7-log reduction on berries throughout the drying and subsequent 2-month storage. HAV showed the greatest decline within the first 14 days of storage of dried berries (ca. 70% weekly reduction from its previous week's level), but the HAV reduction rates were still lower than that occurring on fresh produce. HIGHLIGHTS

Preventing nosocomial infection is a major unmet need of our times. Existing air decontamination technologies suffer from demerits such as toxicity of exposure, species specificity, noxious gas emission, environment-dependent performance and high power consumption. Here, we present a novel technology called “ZeBox” that transcends the conventional limitations and achieves high microbicidal efficiency. In ZeBox, a non-ionizing electric field extracts naturally charged microbes from flowing air and deposits them on engineered microbicidal surfaces. The surface’s three dimensional topography traps the microbes long enough for them to be inactivated. The electric field and chemical surfaces synergistically achieve rapid inactivation of a broad spectrum of microbes. ZeBox achieved near complete kill of airborne microbes in challenge tests (5–9 log reduction) and $$>90\%$$ > 90 % efficiency in a fully functional stem cell research facility in the presence of humans. Thus, ZeBox fulfills the dire need for a real-time, continuous, safe, trap-and-kill air decontamination technology.

Background The hospital environment has got more attention as evidence as source for bacterial transmission and subsequent hospital-acquired infection increased. Regular cleaning and disinfection have been proposed to lower the risk of infection, in particular for gram-positive bacteria. Auto-disinfecting surfaces would allow to decrease survival of pathogens, while limiting resource to achieve a safe environment in patient rooms. Methods A controlled trial to evaluate the antimicrobial effectiveness of a polyvinyl chloride foil containing an integrated silver-based agent (containing silver ions 2%) on high-touch surfaces in patient rooms. Results The overall log reduction of the mean values was 1.8 log10 CFU, the median 0.5 log10 CFU comparing bioburden of control vs antimicrobial foil (p Conclusions A foil containing an integrated silver-based agent applied to high-touch surfaces effectively results in lower recovery of important pathogens from such surfaces over a 6-month study period.

Bovine blood samples were treated with high hydrostatic pressure (HHP) to examine the changes that may occur in the blood related to its colour, microbiological characteristics, protein denaturation, and dynamic viscosity. Pressure treatments were carried out from 100 to 600 MPa in 100 MPa scale up, with 5 min holding time. The blood samples were treated with anticoagulant (EDTA) to eliminate the possible measurement distorting effects. We found that 2 log reduction in the microbial load could be achieved with a pressure treatment above 400 MPa. According to the protein denaturation measurements (DSC), blood proteins were resistant to pressure treatment, even at 300–400 MPa a substantial part of proteins remained in native state. The colour of the samples got darker with the rising pressure, however, visible colour change was observed only above 400 MPa. It can be established, that the HHP treatment was suitable to increase the microbiological stability of blood, without significantly changing its techno-functional properties.

The purposes of this study were to evaluate the inactivation effects of intense pulsed light (IPL) on indigenous and inoculated microorganisms in fresh and minimally processed foods and the industrial applicability of this nonthermal sterilization method. The samples were treated with IPL by varying the treatment time and voltage. The inactivation effect tended to increase as the treatment conditions increased. Further, indigenous microorganisms showed a lower inactivation level than inoculated microorganisms, E. coli ATCC 25922, due to the variability of indigenous microorganisms and their properties. Chopped garlic showed a higher E. coli inactivation effect (2.65 log reduction after 0.185 J/cm(2) of IPL) than peeled garlic (1.21 log reduction) due to its larger surface area. The manila clam showed a lower E. coli inactivation (0.93 log reduction) effect than squid (1.84 log reduction) due to its rougher surface. After the IPL treatment, there was no significant difference in temperature, moisture content, and color.

In recent years, high temperature short time (HTST) treatment technology has been increasingly adopted for medium treatment to mitigate the potential risk of viral contamination in mammalian cell culture GMP manufacturing facilities. Mouse minute virus (MMV), also called minute virus of mice (MVM), implicated in multiple viral contamination events is commonly used as a relevant model virus to assess the effectiveness of HTST treatment of cell culture media. However, results from different studies vary broadly in inactivation kinetics as well as log reduction factors (LRFs) achieved under given treatment conditions. To determine whether the reported discrepancies stemmed from differences in MMV strains, laboratory-scale HTST devices, medium matrices, and/or experimental designs, we have taken a collaborative approach to systematically assess the effectiveness of HTST treatment for MMV inactivation. This effort was conceptualized based on a media treatment gap analysis conducted by the Consortium on Adventitious Agent Contamination in Biomanufacturing (CAACB) under the MIT Center for Biomedical Innovation (CBI). Specifically, two different MMV strains were used to evaluate the effectiveness of HTST at various treatment conditions with regard to exposure temperature and hold time duration by two independent laboratories within two different companies. To minimize experimental variations, the two sites used the same batches of MMV stocks, the same commercially purchased medium, and the same model of thermocyclers as the laboratory-scale HTST device. The two independent laboratories yielded similar MMV inactivation kinetics and comparable LRF. No significant differences were observed between the two MMV strains evaluated, suggesting that the variations from prior studies were likely due to differences in equipment, medium matrices, or other factors. The data presented here indicate that MMV inactivation by HTST treatment obeys first-order kinetics and can be mathematically modeled using an Arrhenius equation. The model-based extrapolation provides a quantitative estimate of MMV inactivation by the current industry standard HTST condition (102°C for a hold time of 10 s) used for medium treatment. Finally, based on the data from the current study and the industry experience, it is recommended that any alternative virus barrier technologies adopted for medium treatment should provide a clearance of at least 3.0 LRF based on a worst-case model virus to effectively mitigate potential risks of viral contamination.

Mobile whole‐room UVGI devices are used in healthcare settings to control surface‐borne pathogens. Unfortunately, no standard method comparing the efficacy of these devices is available. We accessed the effect of shadows on UVC 254 nm inactivation. The evaluation of a mobile whole‐room UVGI device used spores of Bacillus atrophaeus as a surrogate for Clostridium difficile and Staphylococcus aureus as a surrogate for MSRA. Inactivation after 10 min of exposure varied significantly depending on whether the spores received direct UV exposure (4.3 log reduction), both direct and reflected UV exposure (3.0–4.0 log reduction) or reflected UV exposure alone (, Mobile whole‐room UVGI devices are used to control surface‐borne pathogens. No standard method comparing the efficacy of these devices is available. We accessed the effect of shadows on UVC (254 nm) inactivation. Our evaluation used spores of B. atrophaeus, surrogate for C. difficile, and S. aureus surrogate for MSRA. Inactivation after 10 min of exposure varied significantly depending on whether the spores received direct UV exposure, both direct and reflected UV exposure or reflected UV exposure alone. Reflected dose ranged from 0.46% to 1.47%. Based on our findings, B. atrophaeus spores should be considered as a model organism for testing.

Although total duration of tyrosine kinase inhibitor (TKI) therapy and of molecular response at 4 log reduction or deeper (MR4) correlates with treatment-free remission (TFR) success after TKI discontinuation, the optimal cut-off values of the duration remain unresolved. Thus, 131 patients were enrolled into the Canadian TKI discontinuation study. The molecular relapse-free survival (mRFS) was defined from imatinib discontinuation till molecular recurrence, that is, major molecular response (MMR) loss and/or MR4 loss. We evaluated mRFS at 12 months after imatinib discontinuation, analyzed it according to the imatinib treatment duration and MR4 duration, and calculated P value, positive (PPV) and negative predictive value (NPV) in the yearly cut-off period of time. The shortest cut-off was sought that met the joint criteria of a P value ≤ 0·05, PPV ≥ 60% and NPV ≥ 60%. We propose six years as the shortest imatinib duration cut-off with a P value 0·01, PPV 68% and NPV 62%: The patients treated with imatinib duration ≥ 6 years showed a superior mRFS rate (61·8%) compared to those with less treatment (36·0%). Also, 4·5 years MR4 duration as the shortest cut-off with a P value 0·003, PPV 63% and NPV 61%: those with MR4 duration ≥ 4·5 years showed a higher mRFS rate (64·2%) than those with a shorter MR4 duration (41·9%).

Seeking a means of sanitizing berries, the effectiveness of steady state levels of gaseous chlorine dioxide (ClO2) against hepatitis A virus (HAV) on laboratory-contaminated berries was determined. The generated ClO2 was maintained with 1 or 2 mg/l air inside a 269-l glove box to treat 50 g batches of blueberries, raspberries, and blackberries, and 100 g batches of strawberries that were immersion coated with HAV. Normalized data for ClO2 (ppm-h/g product) is reported as a function of ClO2 concentration, treatment time, and weight of treated product. Treatments of ClO2 ranging from 1.00 to 6.27 ppm-h/g berry were evaluated. When compared to untreated HAV-contaminated berries, log reductions of HAV were > 2.1 for all berry types and conditions tested indicating the gaseous ClO2 was effective. The average log reduction with strawberries, raspberries, blueberries and blackberries treated with 1.00 ppm-h/g, the lowest ClO2 treatment tested, were 2.44, 2.49, 3.23, and 3.45, respectively. The highest treatment of 6.27 ppm-h/g was applied at two different gas concentrations of 1 mg/l and 2 mg/l. Average log reductions for blueberries and strawberries treated with 6.27 ppm-h/g were 4.34 and 4.42, and 4.03 and 3.51, applied at 1 mg/l and 2 mg/l, respectively. For blackberries and raspberries 3.20 and 3.24, and 3.23 and 3.97 log reductions were observed for 6.27 ppm-h/g treatments applied at 1 mg/l and 2 mg/l, respectively. Results indicate that HAV contamination of berries can be substantially reduced by gaseous ClO2 and offer industry a waterless means of sanitizing berries against HAV.

The aim of this work was to assess the effectiveness of dipping chicken breast in lactic, malic and fumaric acid 3% solutions for 15 s on Salmonella counts, as well as on chicken meat quality and sensory characteristics. All three treatments effectively reduced Salmonella counts. The values of Salmonella log reduction were 2.22, 1.55 and 1.30 log CFU/g for fumaric, malic and lactic treatments, respectively. Although fumaric acid was the most effective for reducing Salmonella counts, chicken meat quality and sensory characteristics were significantly affected, even in cooked samples. Conversely, malic and lactic acids treatments caused minimal changes in chicken meat quality and sensory characteristics compared to control samples. This study shows effective alternatives to reduce Salmonella contamination on chicken breast fillets, although further studies should be considered to improve the effects on quality and sensory attributes.

This study aimed to compare the thermal resistance of Salmonella Senftenberg 775 W with other serovars of Salmonella in nonfat dry milk (NDM) and hydrated NDM. The scientific literature suggests that Salmonella Senftenberg 775 W is the most heat-resistant serovar in high-water-activity foods such as milk, but little is known about the heat resistance of Salmonella Senftenberg 775 W compared with other Salmonella serovars in low-water-activity foods such as NDM. The 5 serovars of Salmonella used in this study were Enteritidis, Montevideo, Newport, Senftenberg, and Typhimurium. The hydration of NDM was conducted at 13% (wt/vol) total solids. The NDM was inoculated with the 5 individual serovars of Salmonella and dried again to its original pre-inoculation water activity. Hydrated NDM was prepared from individually inoculated NDM. The surviving Salmonella population at predetermined time-temperature intervals were enumerated using injury-recovery medium, and the average log reductions for the individual serovars were calculated. As expected, Salmonella Senftenberg 775 W was the most heat-resistant serovar in hydrated NDM at 59°C and 65°C. However, the heat resistance of Salmonella Senftenberg 775 W was found to be lower than or comparable to that of other serovars in low-water-activity NDM at 80°C and 90°C.

BACKGROUND: Circulation of hepatitis E virus (HEV) in areas where plasma is sourced for the manufacture of plasma-derived medicinal products (PDMPs) has prompted verification of HEV clearance. HEV exists as quasi lipid-enveloped (LE) and non–lipid-enveloped (NLE) forms, which might be of relevance for HEV clearance from manufacturing processes of antibody-containing PDMPs with solvent/detergent (S/D) treatment upstream of further clearance steps. STUDY DESIGN AND METHODS: Presence of different HEV particles in stocks used in clearance studies was investigated, with nanofilters graded around the assumed HEV particle sizes and by gradient centrifugation. HEV removal by 35-nm nanofiltration was investigated in the presence or absence of HEV antibodies, in buffer as well as in immunoglobulin (IG) manufacturing process intermediates. RESULTS: HEV particles consistent with LE, NLE, and an “intermediate” (IM) phenotype, obtained after S/D treatment, were seen in different HEV stocks. In the absence of HEV antibodies, log reduction factors (LRFs) of 4.0 and 2.5 were obtained by 35-nm nanofiltration of LE and IM HEV, consistent with the larger and smaller sizes of these phenotypes. Addition of HEV antibodies enhanced IM HEV removal around 1000-fold (LRF, 5.6). Effective (LRF, >4.8 and >4.0) HEV removal was obtained for the nanofiltration processing step for IG intermediates with varying HEV antibody content. CONCLUSION: HEV spikes used in clearance studies should be carefully selected, as differences in physicochemical properties might affect HEV clearance. Antibody-mediated enhancement of HEV nanofiltration was demonstrated in IG process intermediates even at low HEV antibody concentration, illustrating the robustness of this manufacturing step.

The current study was conducted to elucidate the impact of encapsulation on the stability and viability of probiotic bacteria (Bifidobacterium bifidum) in cheddar cheese and in vitro gastrointestinal conditions. Purposely, probiotics were encapsulated in two hydrogel materials (kepa carrageenan and sodium alginate) by using an internal gelation method. Cheddar cheese was supplemented with unencapsulated/free and encapsulated probiotics. The product was subjected to physicochemical (pH, titrable acidity, moisture, and protein) and microbiological analysis for a period of 35 days of storage. Furthermore, the probiotics (free and encapsulated) were subjected to simulated gastrointestinal conditions. The initial probiotic count in cheese containing encapsulated probiotic was 9.13 log CFU/g and 9.15 log CFU/g which decreased to 8.10 log CFU/g and 7.67 log CFU/g while cheese containing unencapsulated probiotic initially 9.18 log CFU/g decreased to 6.58 log CFU/g over a period of 35 days of storage. The incorporation of unencapsulated and encapsulated probiotic affected the physicochemical, microbiological, and sensory attributes of the cheese. The encapsulated probiotic bacteria exhibited better survival as compared to unencapsulated probiotic. A 2.60 CFU/g log reduction in unencapsulated cells while just 1.03 CFU/g and 1.48 CFU/g log reduction in case of sodium alginate and K‐carrageenan, respectively, was recorded. In short, encapsulation showed protection and stability to probiotic in hostile conditions.

Background Cutibacterium acnes is the most common pathogen in shoulder prosthetic joint infections. Short-contact benzoyl peroxide (BPO) solutions effectively reduce C acnes loads on the shoulder preoperatively. It is unknown how long the effect of BPO lasts. We evaluated C acnes counts 1 week after BPO application. We hypothesized that BPO would decrease C acnes burden with a rebound after 1 week. Methods Screening of 102 healthy volunteers with no history of shoulder surgery or C acnes infection was performed to establish bacterial counts. Thirty-four participants were selected based on an established threshold. Each was given BPO 5% for 3 consecutive days of application on either the left or right shoulder as indicated by a random number generator. Deep sebaceous gland cultures were obtained with a detergent scrub technique before BPO application, after 3 days of use, and 1 week after BPO treatment commenced. Results The differences between the logarithmic reduction and the logarithmic rebound at the anterior, lateral, and posterior sites were statistically significant. Anteriorly, the average log reduction was −0.44 and the average log rebound was 0.69 (P = .003). Laterally, reduction was −0.64 and rebound was 0.74 (P = .003). Posteriorly, reduction was −0.63 and rebound was 0.78 (P = .008). At the axilla, reduction was −0.40 and rebound was 0.31 (P = .10). The differences in C acnes burden between pretreatment and 1-week counts at all sites were not statistically significant. Conclusion A significant decrease in C acnes burden occurred after BPO application but was not permanent. Significant rebound occurred just 1 week later.

The aim of the present study was to evaluate the upshot of microencapsulation on the stability and viability of probiotics in carrier food (ice cream) and simulated gastrointestinal (GIT) conditions. Purposely, Lactobacillus casei was encapsulated with two different hydrocolloids, that is, calcium alginate (Ca‐ALG) and whey protein concentrate (WPC) by using encapsulator. The obtained microbeads were characterized in terms of encapsulation efficiency and morphological features. Afterward, the probiotics in free and encapsulated form were incorporated into ice cream. The product was subjected for physicochemical, microbiological, and sensory attributes over a storage period of 80 days. Microencapsulation with both hydrogels significantly (p, Encapsulation technology allows effective delivery of probiotics and sensitive ingredients through food systems/Carrier ice cream is an potential vehicle for probiotic carrier.

Two novel Sn(iv) tetraisopropylphenylporphyrins have been synthesized to explore the effect of octabromination at the β-pyrrole positions on their photophysical properties and photodynamic activity. The lower energy Q band of an octabrominated complex lies at 675 nm well within the therapeutic window. The octabrominated dye has a relatively high singlet oxygen quantum yield of 0.78 in DMF and exhibits favorable photodynamic activity against MCF-7 cells with an IC50 value of 10.7 μM and a 5.74 log reduction value (5 μM) towards S. aureus under illumination at 660 nm for 60 min with a Thorlabs M660L3 LED (280 mW cm-2).

Huanglongbing (HLB) or greening currently is the most devastating citrus disease worldwide. The fastidious phloem-colonizing bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) is the causal agent of citrus HLB in Florida. Bactericides containing the active ingredient oxytetracycline (OTC) have been used in foliar spray to control citrus HLB in Florida since 2016. However, the minimum concentration of OTC required to suppress CLas in planta remains unknown. We developed a new method for evaluating the effects of OTC treatment on CLas titers in infected plants and determined the relationship between OTC residue levels and control levels achieved for CLas using mathematical modeling in greenhouse and field experiments. In both greenhouse and field, OTC spray did not reduce the titers of CLas, and it produced undetectable or mild levels of OTC residue in leaves within 7 days post-application (DPA). In greenhouse, OTC injection at 0.05 g per tree decreased CLas titers to an undetectable level (cycle threshold value ≥ 36.0) from 7 to 30 DPA and produced a residue level of OTC at 0.68 to 0.73 µg/g of fresh tissue over this period. In the field, OTC injection at 0.50 g per tree resulted in the decline of CLas titers by 1.52 log reduction from 14 to 60 DPA, with residue levels of OTC at 0.27 to 0.33 µg/g of fresh tissue. In both trials, a first-order compart model of OTC residue dynamics in leaves of trunk-injected trees was specified for estimating the retention of effective concentrations. Furthermore, nonlinear modeling revealed significant positive correlations between OTC residue levels in leaves and the control levels for CLas achieved. The results suggested that the minimum concentrations of OTC required to suppress CLas populations in planta to below the detection limit are 0.68 and 0.86 µg/g and that the minimum concentrations of OTC required for initial inhibition of CLas growth in planta are ∼0.17 and ∼0.215 µg/g in leaf tissues under greenhouse and field conditions, respectively. This finding highlights that a minimum concentration of OTC should be guaranteed to be delivered to target CLas in infected plants for effective control of citrus HLB.

Salmonella enteritidis (S. enteritidis) infection has been recognized as one of the most common bacterial causes of human gastroenteritis worldwide and is closely associated with eggs. Slightly acidic electrolyzed water (SAEW) is an emerging environmentally friendly technology for disinfecting eggshell surfaces to remove dirt and pathogenic microorganisms. However, the efficiency of SAEW could be affected by the presence of manure. UV-based advanced oxidation processes have been studied to improve the microorganism's inactivation effect of disinfection. Therefore, in this study, the synergistic bactericidal efficacy of SAEW and UV-C light (ultraviolet lamp, λ = 254 nm) for inactivation of S. enteritidis on artificially inoculated eggshells with or without manure was evaluated, and the bactericidal efficacy of different combination treatments of SAEW and UV-C light was compared. Without manure interference, complete inactivation (reduction of 6.54 log10 CFU/g) of S. enteritidis on the surface of eggshells was achieved following a 4-min treatment with SAEW+UV at an available chlorine concentration (ACC) of 20 mg/L. In the presence of manure, a 3.02 log reduction was achieved following a 4-min treatment with SAEW+UV at an ACC of 30 mg/L. Simultaneous treatment with SAEW and UV light exhibits higher bactericidal activity for eggshells than other combination process methods with UV and SAEW. The results suggest that the combined treatment of SAEW+UV is a novel method to enhance the microbial safety of eggshells.

Although SARS-CoV-2 is primarily an airborne risk, the COVID-19 pandemic also highlighted the need for self-disinfection surfaces that could withstand the demand of high occupant densities characteristic of public transportation systems. The aim of this study was to evaluate the durability and antiviral activity of a copper film deployed for 90 days in two high touch locations within an active metropolitan bus and railcar. The antiviral efficacy of this copper film after being deployed in transit vehicles for 90 days (deployed copper film) was then compared to new (unused) copper film to determine if frequent touches and cleaning protocols could decrease the efficacy of the copper films. Deployed copper film, new copper film, and aluminium foil (positive control) coupons were inoculated with ~1 × 106 MS2 virus particles, allowed a contact time of either 5- or 10-min, and analysed for residual viral infectiousness. On both new and deployed copper films, MS2 was completely inactivated (≥5 log reduction) at both time points. These results suggest that the copper film may provide the durability demanded by high touch public spaces while maintaining the antiviral activity necessary to reduce exposure risk and viral transmission via surfaces in public transportation settings.

Understanding and managing the risk posed by helminth eggs (HE) is a key concern for wastewater engineers and public health regulators. The treatment processes that produce recycled water from sewage at wastewater treatment plants (WWTPs) rely on achieving a defined log10 reduction value (LRV) in HE concentration during the production of recycled water from sewage to achieve the guideline concentration of ≤1.0 HE/L. The total concentration of HE in sewage reaches thousands of HE/L in developing countries and therefore, an LRV of 4.0 is generally accepted to achieve a safe concentration in recycled water, as this will meet the guideline value. However, in many developed countries with good sanitation and public health standards, the HE concentration in sewage is generally

The design of bioaffinity-based targeted delivery systems for biofilm inactivation may require a comprehensive understanding of physicochemical and biochemical properties of biobased antimicrobial particles and their interactions with biofilm. In this study, Escherichia coli biofilm inactivation by chlorine-charged yeast microparticles was numerically simulated, and the roles of chemical stability, binding affinity, and controlled release of this targeted delivery system were assessed using this numerical simulation. The simulation results were experimentally validated using two different types of yeast microparticles. The results of this study illustrate that chorine stability achieved by yeast microparticles was a key factor for improved biofilm inactivation in an organic-rich environment (>6 additional log reduction in 20 min compared to the free chlorine treatment). Moreover, the binding affinity of yeast microparticles to E. coli biofilms was another key factor for an enhanced inactivation of biofilm, as a 10-fold increase in binding rate resulted in a 4.2-fold faster inactivation. Overall, the mechanistic modeling framework developed in this study could guide the design and development of biobased particles for targeted inactivation of biofilms.

ImportanceParticulate respirators such as N95 masks are an essential component of personal protective equipment (PPE) for front-line workers. This study describes a rapid and effective UVC irradiation system that would facilitate the safe re-use of N95 respirators and provides supporting information for deploying UVC for decontamination of SARS-CoV-2 during the COVID19 pandemic.ObjectiveTo assess the inactivation potential of the proposed UVC germicidal device as a function of time by using 3M® 8211 - N95 particulate respirators inoculated with SARS-CoV-2.DesignA germicidal UVC device to deliver tailored UVC dose was developed and snippets (2.5cm2) of the 3M-N95 respirator were inoculated with 106 plaque-forming units (PFU) of SARS-CoV-2 and were UV irradiated. Different exposure times were tested (0-164 seconds) by fixing the distance between the lamp (10 cm) and the mask while providing an exposure of at least 5.43 mWcm-2.SettingThe current work is broadly applicable for healthcare-settings, particularly during a pandemic such as COVID-19.ParticipantsNot applicable.Main Outcome(s) and Measure(s)Primary measure of outcome was titration of infectious virus recovered from virus-inoculated respirator pieces after UVC exposure. Other measures included the method validation of the irradiation protocol, using lentiviruses (biosafety level-2 agent) and establishment of the germicidal UVC exposure protocol.ResultsAn average of 4.38×103 PFUml-1(SD 772.68) was recovered from untreated masks while 4.44×102 PFUml-1(SD 203.67), 4.00×102 PFUml-1(SD 115.47), 1.56×102 PFUml-1(SD 76.98) and 4.44×101 PFUml-1(SD 76.98) was recovered in exposures 2s,6s,18s and 54 seconds per side respectively. The germicidal device output and positioning was monitored and a minimum output of 5.43 mWcm-2 was maintained. Infectious SARS-CoV-2 was not detected by plaque assays (minimal level of detection is 67 PFUml-1) on N95 respirator snippets when irradiated for 120s per side or longer suggesting 3.5 log reduction in 240 seconds of irradiation.Conclusions and RelevanceA scalable germicidal UVC device to deliver tailored UVC dose for rapid decontamination of SARS-CoV-2 was developed. UVC germicidal irradiation of N95 snippets inoculated with SARS-CoV-2 for 120s per side resulted in 100% (3.5 log in total) reduction of virus. These data support the reuse of N95 particle-filtrate apparatus upon irradiation with UVC and supports use of UVC-based decontamination of SARS-CoV-2 virus during the COVID19 pandemic.

This study investigated how the following four intense pulsed light (IPL) treatment factors affect the inactivation of Bacillus subtilis (KCCM 11,315) spores: distance between the sample and IPL lamp (8, 13, and 18 cm), pulse width (0.5, 1.3, and 2.1 ms), charging voltage (1000, 1200, and 1400 V), and processing time (10, 20, and 30 s). The results showed that all four factors considerably influenced the spore inactivation rate in different ways. Excluding processing time, which does not affect the pulse itself, the effect was largest for pulse width, followed by distance, and charging voltage. The optimal treatment condition that maximized the inactivation rate was a distance of 8 cm, a pulse width of 2.1 ms, a charging voltage of 1000 V, and a processing time of 30 s, which together produced a 6 log reduction. It revealed that individual factors need to be investigated together for achieving the optimal condition of IPL.

Consumers' quest for healthier, locally produced foods, renders the demand for these products increasingly prominent. The purpose of the present work was to evaluate the impact of a non-thermal multi-hurdle approach, which associated mild high hydrostatic pressure (HHP, 300 MPa), the bacteriophage Listex™ P100, and the pediocin PA-1 producing Pediococcus acidilactici HA 6111-2, as a novel minimal processing towards Listeria monocytogenes eradication in Alheira (a traditional fermented meat sausage from Northern Portugal). The combination of the three hurdles achieved the USDA-FSIS 5 log reduction (in accordance with the standard guidelines for ready-to-eat foods), being the only treatment to elicit the absence of L. monocytogenes immediately following processing (p 0.05) in the pH values were observed, and the semi-quantification of the in situ biosynthesized pediocin PA-1 was documented for the first time in a fermented meat sausage model. published