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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.

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 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.

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.

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

Objective Microbial analysis in milk preserved using heat-assisted Pulsed Electric Field (PEF) need to be assessed. In this study we analyze the microbial quality and virulence-associated genes in milk samples preserved using heat-assisted PEF from several producers in Indonesia. Results Milk samples were collected consisting of raw milk, milks taken after the heating, PEF, mixing, cooling, and packaging. Microbiological and Polymerase Chain Reaction (PCR) detection for virulence genes were performed. Heat-assisted PEF treatment gave 2.7–7.47 log reduction for TPC; 1.6–2.56 log reduction for MPN number; 3.13–6.48 log reduction for S. aureus; and for B. cereus there was an increase of 0.76 log and a reduction of 0.46 log. While milk samples from thermal pasteurization gave log reduction numbers of TPC, MPN, and S. aureus respectively 5.28; 2.56; and 4.73, for B. cereus was increasing 2.4 log. Producer C performed the best results with significant reduction compared with others (p L. monocytogenes found in all of the samples. PCR results showed that milk samples possessed virulence genes 17.5% (10/57) of invA genes, 54.4% (31/57) of nheA genes, 68.4% (39/57) of cytK genes, 38.6% (22/57) of nuc genes, 63.2% (36/57) of ileS genes, while hly and actA genes were not detected.

A preliminary quantitative microbial risk assessment of Vibrio parahaemolyticus in short mackerels was conducted from retail to consumption levels in a stochastic model. The key uncertainties included of growth during retail display, transportation duration, and microbial log reduction after the preparation and cooking steps were taken into consideration in the exposure assessment. Human health risk associated with the consumption of short mackerels contaminated with pathogenic V. parahaemolyticus was predicted by fitting the number of cells ingested into a Beta-Poisson dose-response model. Advanced sensitivity analysis was performed to determine the predictive factors most highly correlated with risk illness. The model evaluated through Monte Carlo simulation revealed an estimated number of illness ranged from 1.34 × 10−4 to 12.80 with an average incidence of 2.07 cases per annum. The rates per 100,000 population were predicted at 6.53 × 10−3 cases per year in Malaysia. In this study, the development of quantitative microbial risk assessment of V. parahaemolyticus in short mackerels provides valuable information such as the probability of illness associated with the consumption of short mackerels and the primary factor quantitatively important for risk illness.

A gap exists between good laboratory practices with axenic animals and the procedures applied. This work examined the efficacy of sodium dichloroisocyanurate (MB-10) and potassium peroxymonosulfate (Virkon™) disinfectants, as well as the appropriate soaking time for materials used with the ISOcage Biosafety Station™. We also compared the microbial load in cage systems hosting mice over 2 weeks in axenic rooms (ARs) and in typical specific-pathogen-free (SPF) non-axenic rooms (NARs) to identify resistant microorganisms, targeted for longer soaking disinfection, and evaluated the necessary procedures for reducing the microbial load in AR. Staphylococcus was the most frequently isolated genus (in both ARs and NARs). An average of three spore-forming microorganisms per cage were counted from AR. The disinfection time to reach 1 log reduction for Bacillus atrophaeus spores varied from 138 s (100 ppm MB-10) to 290 (Virkon™) to

There is increasing interest in wastewater-based epidemiology (WBE) of SARS-CoV-2 RNA to serve as an early warning system for a community. Despite successful detection of SARS-CoV-2 RNA in wastewaters sampled from multiple locations, there is still no clear idea on the minimal number of cases in a community that are associated with a positive detection of the virus in wastewater. To address this knowledge gap, we sampled wastewaters from a septic tank (n = 57) and biological activated sludge tank (n = 52) located on-site of a hospital. The hospital is providing treatment for SARS-CoV-2 infected patients, with the number of hospitalized patients per day known. It was observed that depending on which nucleocapsid gene is targeted by means of RT-qPCR, a range of 253–409 positive cases out of 10,000 persons are required prior to detecting RNA SARS-CoV-2 in wastewater. There was a weak correlation between N1 and N2 gene abundances in wastewater with the number of hospitalized cases. This correlation was however not observed for N3 gene. The frequency of detecting N1 and N2 gene in wastewater was also higher than that for N3 gene. Furthermore, nucleocapsid genes of SARS-CoV-2 were detected at lower frequency in the partially treated wastewater than in the septic tank. In particular, N1 gene abundance was associated with water quality parameters such as total organic carbon and pH. In instances of positive detection, the average abundance of N1 and N3 genes in the activated sludge tank were reduced by 50 and 70% of the levels detected in septic tank, suggesting degradation of the SARS-CoV-2 gene fragments already occurring in the early stages of the wastewater treatment process., Graphical abstract Image 1, Highlights • 253 to 409 positive cases out of 10,000 persons are required prior to detecting SARS-CoV-2 RNA in wastewater. • N1 and N2 gene abundance exhibit weak positive correlation with number of patients. • N1 gene provides better sensitivity and correlation for use as monitoring marker. • Abundance of N1 gene associated with total organic carbon and pH. • N1 and N3 genes were reduced by > 50% in partially treated wastewater but N2 genes abundance increased.

Bivalve mollusk contamination by enteric viruses, especially human noroviruses (HuNoV) and hepatitis A virus (HAV), is a problem with health and economic implications. The aim of the study was the evaluation of the effect of heat treatment in clams (Tawera gayi) experimentally contaminated with HuNoV using a PMA-viability RTqPCR assay to minimize measurement of non-infectious viruses, and used HAV as a model to estimate infectivity loss. Spiked clams were immersed in water at 90°C to ensure that internal meat temperature was maintained above 90°C for at least 5 min. The treatment resulted in >3.89 ± 0.24 log10TCID50/g reduction of infectious HAV, confirming inactivation. For HuNoV, RTqPCR assays showed log10reductions of 2.96 ± 0.79 and 2.56 ± 0.56, for GI and GII, respectively, and the use of PMA resulted in an additional log10reduction for GII, providing a better correlation with risk reduction. In the absence of a cell culture system which could be used to determine HuNoV infectivity reduction, a performance criteria based on PMA-RTqPCR log reduction could be used to evaluate food product safety. According to data from this study, heat treatments of clams which cause reductions >3.5 log10for GII as measured by PMA-RTqPCR assay may be regarded as an acceptable inactivation treatment, and could be set as a performance criterion to test the effectiveness of other time-temperature inactivation processes.

Listeria monocytogenes has caused outbreaks of foodborne illness from apples in the USA, and is also a major issue for regulatory compliance worldwide. Due to apple's significance as an important export product from New Zealand, we aimed to determine the effect of long-term, low-temperature sea-freight from New Zealand to the USA (July) and Europe (March–April), two key New Zealand markets, on the survival and/or growth of L. monocytogenes on fresh apples. Temperature and humidity values were recorded during a shipment to each market (USA and Europe), then the observed variations around the 0.5 °C target temperature were simulated in laboratory trials using open (‘Scired’) and closed (‘Royal Gala’ for the USA and ‘Cripps Pink’ for Europe) calyx cultivars of apples inoculated with a cocktail of 107–108 cells of seven strains of L. monocytogenes. Samples were analysed for L. monocytogenes quantification at various intervals during the simulation and on each occasion, an extra set was analysed after a subsequent 8 days at 20 °C. When both the sea-freight simulations concluded, L. monocytogenes showed 5 log reductions on the equatorial surface of skin of apples, but only about 2.5 log reduction for USA and about 3.3 log reduction for Europe in the calyx. Cultivar type had no significant effect on the survival of L. monocytogenes for both sea-freight simulations, either in the calyx or on the skin (P > 0.05). Most of the reduction in the culturable cells on the skin occurred during the initial 2 weeks of the long-term storage simulations. There was also no significant difference in the reduction of L. monocytogenes at 0.5 or 20 °C. No correlation was observed between firmness or total soluble solids and survival of L. monocytogenes. Because the inoculated bacterial log reduction was lower in the calyx than on the skin, it is speculated that the risk of causing illness is higher if contaminated apple cores are eaten. The result suggested that the international sea-freight transportation does not result in the growth of L. monocytogenes irrespective of time and temperature. The results of this study provide useful insights into the survival of L. monocytogenes on different apple cultivars that can be used to develop effective risk mitigation strategies for fresh apples during long-term, low-temperature international sea-freight transportation.

Hepatitis E virus (HEV) causes acute hepatitis with approximately 20 million cases per year globally. While HEV is endemic in certain regions of Asia, Africa and South America, it is considered an emerging foodborne pathogen in developed countries. Based on genetic diversity, HEV is classified into different genotypes, with genotype 3 (HEV-3) being most prevalent in Europe and North America. The transmission of HEV-3 has been shown to be zoonotic and mainly associated with the consumption of raw or undercooked pork products. Herein, we investigated the efficacy of high-pressure processing (HPP) in the inactivation of HEV-3 using a cell culture system. HPP has been indicated as a promising nonthermal pathogen inactivation strategy for treatment of certain high-risk food commodities, without any noticeable changes in their nature. For this purpose, we treated HEV-3 in media as well as in artificially inoculated pork pâte, with different conditions of HPP: 400 MPa for 1 and 5 minutes, as well as 600 MPa for 1 and 5 minutes, at ambient temperature. In general, we observed approximately a 2-log reduction in HEV load by HPP treatments in media; however, similar treatment in the pork pâte resulted in a much lower reduction in viral load. Therefore, the efficacy of HPP treatment in the inactivation of HEV-3 is matrix-dependent. Importance HEV is an emerging foodborne pathogen in industrialized countries, and its transmission is associated with the consumption of contaminated undercooked pork product. In this work, we employed an infectivity assay to investigate the potential of high-pressure in inactivation of HEV in media and ready-to-eat pork pâte. We demonstrated that the effect of HPP on inactivation of HEV depends on the surrounding matrix.

Dry-cured ham is a shelf-stable product that can be contaminated with Listeria monocytogenes due to post-processing operations, compromising the compliance of zero tolerance policies (e.g. US Listeria rule). The present study quantifies the behavior of L. monocytogenes in sliced Spanish dry-cured ham of different water activity (aw) during storage at different temperatures. Inactivation kinetics were estimated by fitting primary models to the experimental data. The effect of temperature and aw on kinetic parameters was characterized through secondary polynomial models. L. monocytogenes viability decreased in all the assayed conditions, confirming that dry-cured ham is not only listeriostatic but listericidal. The fastest and highest reductions were observed at 25 °C, with 1 Log reduction after 6 and 9 days in Iberian and Serrano ham respectively. The work provides scientifically-based data and models to design a low-cost control measure based on a corrective storage as a post-lethality treatment to enhance the accomplishment of zero-tolerance requirements. info:eu-repo/semantics/acceptedVersion

Objective Reprocessing reusable medical devices is crucial in the healthcare industry. To ensure patient safety, strict standards are dictated to validate thermal disinfection in automated washer-disinfectors. The United States Food and Drug Administration (FDA) has specific recommendations on the vegetative bacterial challenge but comparatively vague guidance on the use of a thermophilic Mycobacterium strain for thermal disinfection studies. This study aims to compare thermal resistance of Mycobacterium hassiacum and Mycobacterium terrae and determine which strain is suitable for medical device thermal disinfection validation testing in automated washer-disinfectors. Results Thermal resistance was demonstrated in vitro by calculating D-values for each strain at different exposure temperatures, and correlated with actual in situ processing conditions. M. terrae was completely killed (> 7 log reduction) at temperatures above 68 °C, with D-values between 46.6 and 27.8 s at temperatures between 59.5 and 67.2 °C. M. hassiacum was completely killed (> 8 log reduction) at temperatures above 75 °C, with D-values between 82.1 and 21.7 s at temperatures ranging between 69.2 and 73.6 °C. In vitro results were correlated in a washer-disinfector performance validation setup.

The present study investigated skimmed milk and alginate-based encapsulation for protection of a probiotic strain, Lactobacillus gastricus BTM7 during storage and exposure to simulated gastrointestinal conditions. The investigations have revealed that coating with skimmed milk and alginate in a ratio of 1:1 resulted in highest encapsulation efficiency of 94% (p

Suspensions of non-pathogenic Listeria innocua ATCC 33090 in water were exposed to different combinations of high hydrostatic pressure (HPP), pulsed electric field (PEF) and sonication treatments. Treatments were conducted individually, or in various combinations – sequential HPP-PEF; sequential PEF-HPP, simultaneous HPP-PEF, sequential HPP-sonication and sequential sonication-HPP. The greatest reduction by an individual treatment was obtained with HPP, wherein exposure to 400 MPa for 100 s resulted in an 8 log reduction in CFU. Both PEF (30 kV, 10−3 s) and sonication (250s) treatments gave about 2 log reduction in the Listeria population. Sequentially applied HPP-PEF, and PEF-HPP treatments demonstrated mostly additive effects. Notably, however, a synergistic effect was observed when PEF and HPP were applied simultaneously. Combinations of HPP and sonication treatments demonstrated synergistic effects when HPP treatment was followed by sonication, but additive effects when sonication was followed by HPP. A relationship between Listeria innocua inactivation and increase in the suspension zeta potential was observed. However, protein content of the supernatant was found insignificant, indicating that leakage from cells were non-protein cell constituents.

Plasma activated water (PAW) has rapidly emerged as a promising alternative to traditional sanitizers applied in the fresh produce industry. In the present study, PAW chemistry and storage stability were assessed as a function of plasma operating conditions. Increasing plasma exposure time (5, 12.5, 20 min) and power (16, 26, 36 W) led to a significant drop in pH (2.4) and higher nitrates and nitrites levels (320 and 7.2 mg/L, respectively) in the PAW. Non-detectable hydrogen peroxide concentration, irrespective of the treatment conditions, was attributed to its instability in acidic environments and the remote PAW generation mode. pH, nitrates and nitrites levels in the PAW remained unaffected after two weeks at 4 &deg, C. The potential of PAW for microbial inactivation and quality retention was demonstrated on baby spinach leaves. Rinsing steps influenced colour development during chilled storage to a greater extent than PAW treatment itself. About 1 log reduction in total bacterial counts (5 log CFU/g) was achieved through PAW rinsing, with no variability after eight days at 4 &deg, C (typical shelf-life at retailers). Moreover, microbial levels on PAW-treated samples after storage were significantly lower than those on control samples, thus contributing to extended product shelf-life and reduced food waste generation.

The use of sulphur dioxide (SO2), high pressure processing (HPP) and pulsed electric fields (PEF) for wine preservation was compared. The difference between HPP and PEF wines and untreated wine after one year's storage, in terms of sensory quality, B. bruxellensis inactivation, colour density, total phenolic content and volatile phenol concentration, was determined. SO2 and HPP led to >5 log inactivation of B. bruxellensis, however SO2 treated cells were able to recover after 10 months storage. PEF treatment provided insufficient inactivation (0.8 log reduction). HPP was the only treatment which prevented Brettanomyces growth and the formation of off-flavours and –odours after storage. SO2 and PEF treatments had no significant effect on wine quality, while the colour and phenolic quality of HPP treated wine deteriorated after six months. HPP and PEF also had no effect on the overall sensory quality of the wines. Overall, HPP was able to produce a microbiologically stable wine, with no effect on the taste of the wine. Industrial relevance Brettanomyces is a spoilage concern in the wine industry, conventionally controlled using SO2. Due to its adverse effects on some consumers, the use of emerging non-thermal technologies has started to garner great interest in the food and beverage industry. The results show that HPP is a non-thermal treatment with the potential to reduce the use of SO2 for the preservation of wine in the industry. However, to extend the quality of HPP treated wine beyond six months storage and retain wine colour and total phenolic content, small doses of SO2 may be required. Since, PEF is a continuous process, integration of this technology into current wine production practices would be less challenging than for HPP. This study also underscores the importance on conducting regular tests for B. bruxellensis contamination in the wine industry, because even when plate counts are negligible this yeast has the ability to recover when conditions become favourable again.

USDA, FSIS thermal processing guidelines (e.g. Appendix A for cooked beef, roast beef, and cooked corned beef, and Time-Temperature Tables for Cooking Ready-to-Eat Poultry Products) are widely used as validation support for cooking processes, but these procedures were developed and validated only for Salmonella in a limited number of products. To determine the extent to which Appendix A can safely be applied to other pathogens and products, a study was conducted to compare the thermal-death times of Salmonella, Listeria monocytogenes, and shiga toxin-producing E. coli (STEC) in model products representing roast beef, turkey breast, and boneless ham. Raw batter for each of the 3 products was inoculated with 8 log CFU/g of a multi-strain mixture of L. monocytogenes, Salmonella, or STEC. One-gram portions of inoculated roast beef, turkey breast, or ham batter were flattened into a thin film in moisture-impermeable pouches, vacuum-packaged, and heated at 54.4, 60.0, 65.6, or 71.1°C in a water bath. Triplicate samples were removed at predetermined time points and enumerated for surviving pathogens. The time needed to yield a 6.5-log reduction of Salmonella and STEC at 60.0, 65.6, or 71.1°C for the three product types was comparable to the times prescribed by USDA, FSIS Appendix A for Salmonella inactivation; however, at 54.4°C similar inactivation levels were not observed. L. monocytogenes showed greater thermotolerance than Salmonella and STEC for all 3 product types. These data suggest that current USDA, FSIS thermal processing guidelines are acceptable tools for ensuring the safety of cooking processes at 60.0°C or higher to inactivate Salmonella and STEC in the product types, but longer dwell times may be necessary to yield comparable log reduction of L. monocytogenes.

Plasma activated water (PAW) generated by atmospheric-pressure air microplasma arrays is a solution containing a variety of reactive species. Here we investigate the effects of different applied voltage and water-activated time on bactericidal activities against Shewanella putrefaciens (S. putrefaciens). Our measurements showed that the sterilization efficiency of S. putrefaciens by PAW could be up to 2.0 Log Reduction. Scanning electron microscopy image and DNA concentration measurement showed that the S. putrefaciens cells were damaged and deformed due to the PAW treatment. The physicochemical properties of PAW treated by different applied voltage and water-activated time were evaluated, including pH value, initial PAW temperature, and the concentrations of plasma-activated species, such as H2O2, NO 3 − , NO 2 − , and O3. Analysis indicates that the sterilization efficiency of S. putrefaciens treated by PAW was mainly determined by H2O2 concentration and pH value of PAW. This study provides a basis for the PAW potential applications in the disinfection of rotten food.

The failure of endodontic treatment is linked to the presence of Enterococcus faecalis in the root canals. The scope of this study was to evaluate the influence of the energy dose and frequency of photodynamic therapy (PDT cycles), as well as the volume of bacterial suspensions (BS) in the elimination of Enterococcus faecalis in planktonic form.In four successive assays BS of Enterococcus faecalis ATCC 19433 were irradiated with a diode laser (40 mW) using the photosensitizer (PS) methylene blue (MB) (0.005 μg/mL). Group 1 - Effect of energy dose: 100 μ L of BS and 100 μ L of PS were irradiated by 1, 2.5, 5, 7.5 and 10 minute s. Group 2 - Effect of PDT cycles: The BS received 1, 2, 3 or 4 PDT cycles (in each cycle 100 m L of PS was added and irradiated by 2.5 minutes). Group 3 - Effect of energy dose and bacterial suspension volume: 10 μ L of BS and 10 μ L of PS were irradiated similar to group 1. Group 4 - Effect of energy dose, bacterial suspension volume and PDT cycles: 10 μ L of BS and 10 μL of PS were irradiated according to group 2. The laser source and MB isolated represented the controls.The mean log reduction after separate applying laser light and MB were 0.01 and 0.07, respectively. It was found that wells with 100 μ L of BS irradiated with 2.4 to 24 J of energy did not cause significant bacterial elimination (p 0.05), on the other hand PDT cycles above 12 J increased significantly bacterial elimination (p 0.05). In 10 μ L wells irradiation from 12 J of energy provided higher bacterial elimination (p 0.05) which combined with PDT cycle resulted in the logarithmic elimination of E. faecalis (p 0.05).The energy dose, the volume of the bacterial suspension and, especially, the PDT cycles optimized the bacterial elimination of Enterococcus faecalis in planktonic form.

Mycoplasma bovis is an important cause of mastitis in dairy cattle, and pneumonia, arthritis, and otitis in calves. Milk and colostrum are considered important sources of infection for calves. knowledge on the effect of on-farm freezing (-18°C) and thawing methods on the recovery of M. bovis from colostrum samples is missing. In this study, 2 separate experiments were performed. The first experiment consisted of a longitudinal study examining the survival [as measured by log(10) reduction] of 2 M. bovis strains in frozen colostrum over 14 wk. The second experiment examined the effect of different thawing temperatures (45 and 20°C), thawing frequencies (once or twice), and initial colostrum titer (104 or 106 cfu/mL) on M. bovis survival. A single freeze-thaw cycle led to an approximate 1 log reduction of M. bovis titer, independent of the thawing temperature. Freezing for 14 wk did not significantly further reduce the titer of bacteria compared with freezing for 2 wk. A second freeze-thaw cycle further reduced the M. bovis count by approximately 0.5 log compared with a single freeze-thaw cycle. Thawing temperature and initial bacterial concentration did not significantly affect M. bovis reduction. In conclusion, storage of colostrum samples in the freezer at -18°C during epidemiological studies, herd monitoring, or test and cull programs will probably have little influence on qualitative bacteriological test results for M. bovis. The epidemiological or clinical relevance of an approximate 1 log reduction of M. bovis in colostrum is currently unclear.

Slightly acidic electrolyzed water (SAEW) is an effective disinfectant used to control food poisoning bacteria. In this study, we evaluated the sterilization effect of an SAEW stock solution and 5–90% SAEW solutions, and the potential for bacterial reactivation after disinfection. SAEW stock solution at ACC of 31.2 ± 0.22 mg/L, pH of 5.51 ± 0.01, ORP of 895 ± 6 mV for disinfection effect assessment was used. SAEW at a concentration of 40% resulted in a >6 log reduction in Yersinia enterocolitica in a suspension test and on cabbage. Analysing the bactericidal efficacies of 5–90% SAEW indicated that a concentration of >70% SAEW thoroughly eliminated Y. enterocolitica. Additionally, SAEW-sterilized cabbage was stored at 5 °C, 10 °C, 20 °C, and 30 °C for one week to investigate the resilience of the damaged bacteria. Following the disinfection with 40% SAEW, cabbage must be stored at a low temperature of 70% SAEW and indicate that the storage temperature of cabbage following the disinfection and washing are important for ensuring food safety.

Recent multistate outbreaks of salmonellosis associated with fresh cucumbers underscore the importance of understanding Salmonella behavior on cucumbers under different conditions. This study developed mathematical models to predict the survival of four-strain cocktail of Salmonella on whole cucumbers at different temperature and relative humidity (RH) conditions. The strains were Salmonella Newport H1275 and Stanley H0558 (sprout outbreaks), Montevideo G4639 (tomato outbreak), and Saintpaul 02-517-1 (cantaloupe outbreak). Inoculated cucumbers were placed in desiccators containing saturated salt solution to create controlled RH environments (~15, 50, 100% RH) at 7, 14, and 21 °C, and enumerated at time intervals ranging from 0 to 240 h. Predictive models were developed using Baranyi and Roberts equation as a primary model and estimated kinetic parameters were fitted into a polynomial equation for secondary models. Reduced model polynomial equations which describe the maximum death rate and the log reduction of Salmonella on whole cucumber as a function of temperature and RH had high R2 values (>0.95). Validation results verified the performance and reliability of the predictive models. The models in this study will be useful for future microbial risk assessments and predictions of Salmonella behavior in the cucumbers to manage the risk of Salmonella on whole cucumbers.

Infant Milk Formula (IMF) is an instant alternative to breastfeeding which is being investigated continuously to mimic the composition of human milk. Hypoallergenic IMF is recommended for infants who cannot tolerate cow milk due to allergy. Paediatric obesity resulted in burgeoning demand for low protein infant formula, especially in Asia. Beta-lactoglobulin (β-Lg), a major cow milk allergen to infants, is present in cow milk as 3–4 g/L, whereas, interestingly, it is absent in human milk. Besides, human milk contains Fe3+ binding lactoferrin (LF) and Ca2+ binding alpha-lactalbumin (α-Lac) about 10 and 3 times, respectively, higher than cow milk. Therefore, a mechanism to formulate a hypoallergenic IMF with low protein content could be the addition of LF and α-Lac and reducing β-Lg at the same time using an appropriate processing method. Hence, as a pragmatic approach, this study considered a pasteurized form of ready-to-feed (RTF) by applying Pressure Assisted Thermal Pasteurization (PATP) achieved from HPP of 600 MPa for 15 s applied at 57.1 °C to attain 72.3 °C after pressurization. In parallel, conventional HTST was also applied at 72 °C for both 15 and 30 s to compare PATP's effect. HTST and PATP retained >90% and > 75% LF respectively whereas PATP induced higher retention of α-Lac compared to HTST. However, HTST retained >60% β-Lg while PATP induced a high denaturation of β-Lg with 28% retention only. Moreover, both PATP and HTST induced around 5 log reduction of E. coli (ATCC 8739) in IMF. Therefore, the current investigation potentially indicates a route to develop a PATP-processed hypoallergenic and low protein RTF formula, a niche product.

Background Schistosomiasis is a parasitic disease that is transmitted by skin contact with waterborne schistosome cercariae. Mass drug administration with praziquantel is an effective control method, but it cannot prevent reinfection if contact with cercariae infested water continues. Providing safe water for contact activities such as laundry and bathing can help to reduce transmission. In this study we examine the direct effect of UV light on Schistosoma mansoni cercariae using ultraviolet light-emitting diodes (UV LEDs) and a low-pressure (LP) mercury arc discharge lamp. Methodology S. mansoni cercariae were exposed to UV light at four peak wavelengths: 255 nm, 265 nm, 285 nm (UV LEDs), and 253.7 nm (LP lamp) using bench scale collimated beam apparatus. The UV fluence ranged from 0–300 mJ/cm2 at each wavelength. Cercariae were studied under a stereo-microscope at 0, 60, and 180 minutes post-exposure and the viability of cercariae was determined by assessing their motility and morphology. Conclusion Very high UV fluences were required to kill S. mansoni cercariae, when compared to most other waterborne pathogens. At 265 nm a fluence of 247 mJ/cm2 (95% confidence interval (CI): 234–261 mJ/cm2) was required to achieve a 1-log10 reduction at 0 minutes post-exposure. Cercariae were visibly damaged at lower fluences, and the log reduction increased with time post-exposure at all wavelengths. Fluences of 127 mJ/cm2 (95% CI: 111–146 mJ/cm2) and 99 mJ/cm2 (95% CI: 85–113 mJ/cm2) were required to achieve a 1-log10 reduction at 60 and 180 minutes post-exposure at 265 nm. At 0 minutes post-exposure 285 nm was slightly less effective, but there was no statistical difference between 265 nm and 285 nm after 60 minutes. The least effective wavelengths were 255 nm and 253.7 nm. Due to the high fluences required, UV disinfection is unlikely to be an energy- or cost-efficient water treatment method against schistosome cercariae when compared to other methods such as chlorination, unless it can be demonstrated that UV-damaged cercariae are non-infective using alternative assay methods or there are improvements in UV LED technology., Author summary Schistosomiasis is a waterborne disease that affects approximately 200 million people globally. It is transmitted through contact with freshwater that contains parasitic larvae known as cercariae and is prevalent in communities that do not have access to safe water supplies. Treatment with the drug praziquantel is effective against adult worms, but this cannot prevent reinfection if contact with contaminated water continues. Providing safe water for laundry and bathing can prevent transmission of the disease and the emerging technology of ultraviolet light-emitting diodes could offer a chemical free option for point-of-use water treatment, but there is insufficient published data to determine the UV fluence-response of schistosome cercariae. In this study we investigate the effectiveness of UV disinfection at four wavelengths against Schistosoma mansoni cercariae. The results show that high UV fluences are required to kill S. mansoni cercariae at all wavelengths, but they are visibly damaged at lower fluences. This suggests UV disinfection alone is unlikely to be an efficient method for providing cercariae-free water unless there are improvements in UV-LED technology or further research can demonstrate UV-damaged cercariae are non-infective.

In this study, thermal processes were developed for cocoa powder against Salmonella and Listeria monocytogenes in a pilot Radiofrequency (RF) unit and validated using their respective surrogates Enterococcus faecium NRRL B-2354 and Listeria innocua. For 1.0 kg cocoa powder samples, RF heating to 90 °C provided 1.74–1.84 log reduction of E. faecium. A 48 min holding post-RF heating provided an additional 3.65 and 2.24 log10 CFU/g reduction of E. faecium for insulated and non-insulated samples, respectively. Compared to E. faecium, L. innocua was less resistant to RF heating in aw 0.45 cocoa powder; RF heating to 75 °C coupled with 24 min insulated holding resulted in an additional 5.64 log10 CFU/g reduction. These data suggested that E. faecium was a conservative surrogate strain for controlling Salmonella and L. monocytogenes during RF processing of cocoa powder. To achieve maximal microbial reduction and improve energy efficiency, an insulated holding following RF heating is highly recommended. According to the predictive line obtained from the Bigelow model, a 7.6 min RF heating plus 48 min insulated holding attained a 5-log reduction of E. faecium without a negative impact on the color of cocoa powder.

Water can be activated by applying plasma to water, for instance, by creating plasma inside (bubbles in) the water, or along a water surface. Plasma-activated water (PAW) typically contains hydrogen peroxide, nitrates, nitrites, and peroxynitrite, and typically has a pH ranging from 2 to 4. The components of PAW and the low pH have proven synergistic antimicrobial effects against bacteria, biofilms, yeasts, and other microorganisms. This paper describes a power modulator and a plasma reactor system for high-yield production of PAW at high production rate. A compact and solid-state dual resonant system has been realized and successfully demonstrated for industrial PAW production. The system generates up to 80-kV (theoretical 120 kV is possible) dual-resonant high-voltage pulses with an oscillation frequency up to 2 MHz, pulse repetition rate > 20 kHz, and an average power of 800-W continuous. In addition to the power modulator, the PAW production system consists of a transient arc plasma reactor and a loop system. Depending on the application, the system is able to activate 10–100 L/h. The disinfecting properties of the PAW production system have been verified by experiments on the reduction of Staphylococcus Epidermidis. Directly after its production, the log reduction of S. Epidermidis can be as high as >8 log. During a period of at least 40 min after its production, the PAW has “mild” disinfecting properties, being able to deactivate S. Epidermidis by 3–4.1 log

Poultry meat is the main source of Campylobacter jejuni foodborne disease. Currently, no effective control measures prevent C. jejuni from contaminating poultry meat. However, post-harvest phage treatment is a promising biocontrol strategy that has not yet been explored. Here we identified phages capable of reducing C. jejuni at chilled temperature by a systematic screening of unique phages of our collection consisting of flagellotropic phages and phages dependent on capsular polysaccharides (CPSs) for infection. Interestingly, CPS phages showed varied killing efficiencies at 5 °C in vitro , ranging from insignificant reduction to 0.55 log reduction. In contrast, none of the flagellotropic phages significantly reduced C. jejuni counts at low temperature. Phage adsorption at 5 °C showed that flagellotropic phages bind reversibly and less efficiently to C. jejuni than CPS phages, which may explain why flagellotropic phages did not reduce C. jejuni . The CPS phages tested showed similar binding capacities. Thus, the varying effectiveness of CPS phages to reduce C. jejuni counts may be attributed to other stages of the phage life cycle than phage binding. Finally, a phage cocktail of the two most effective phages (F356 showing 0.49 and F357 showing 0.55 log reductions, respectively) led to a 0.73 log reduction of C. jejuni on artificially contaminated chicken skin. Our study shows that poly-phage treatment at 5 °C can be more effective against C. jejuni compared to single phage application. A thorough understanding of phage-host interactions is prerequisite to further advance phage application as a post-harvest biocontrol strategy against C. jejuni.

Aims The goal of this study was to explore various models for describing viral persistence (infectivity) on fomites and identify the best fit models. Methods and Results The persistence of poliovirus over time was studied on three different fomite materials: steel, cotton, and plastic. Known concentrations of poliovirus type 1 were applied to the surface coupons in an indoor environment for various lengths of time. Viruses were recovered from the surfaces by vortexing in phosphate buffer. Seven different mathematical models of relative persistence over time were fit to the data, and the preferred model for each surface was selected based on the Bayesian Information Criterion. Conclusions While the preferred model varied by fomite type, the virus showed a rapid initial decay on all of the fomite types, followed by a transition to a more gradual decay after about 4 to 8 days. Estimates of the time for 99% reduction ranged from 81 hours for plastic to 143 hours for cotton. A 6 log reduction of recoverable infectivity of poliovirus did not occur during the 3 week duration of the experiment for any of the fomites. Significance and Impact In protected indoor environments poliovirus can remain infective for weeks. The models identified by this study can be used in risk assessments to identify appropriate strategies for managing this risk. This article is protected by copyright. All rights reserved.

International audience; A well-known probiotic strain, L. rhamnosus GG, was encapsulated by spray-drying in milk water insoluble matrices upon reconstitution in hot water by exploiting and controlling the clotting reaction of milk proteins during the process. The feed solution, composed of probiotic bacteria and milk proteins, was or not subjected to the action of chymosin, a proteolytic enzyme. To optimize microencapsulation efficiency, different outlet air temperatures were tested (55, 70 and 85 degrees C). After spray-drying, small microparticles were recovered for further characterization. All drying conditions led to excellent bacterial survival rates (

This study aimed to evaluate the impacts of morphological-controlled ZnO nanoarchitectures on aerobic microbial communities during real wastewater treatment in an aerobic-photocatalytic system. Results showed that the antibacterial properties of ZnO nanoarchitectures were significantly more overwhelming than their photocatalytic properties. The inhibition of microbial activities in activated sludge by ZnO nanoarchitectures entailed an adverse effect on wastewater treatment efficiency. Subsequently, the 16S sequencing analysis were conducted to examine the impacts of ZnO nanoarchitectures on aerobic microbial communities, and found the significantly lower microbial diversity and species richness in activated sludge treated with 1D-ZnO nanorods as compared to other ZnO nanoarchitectures. Additionally, 1D-ZnO nanorods reduced the highest proportion of Proteobacteria phylum in activated sludge due to its higher proportion of active polar surfaces that facilitates Zn2+ ions dissolution. Pearson correlation coefficients showed that the experimental data obtained from COD removal efficiency and bacterial log reduction were statistically significant (p-value

This study aimed to identify the bacterial community in two wastewater treatment plants (WWTPs) and to determine the occurrence and reduction of Arcobacter, along with virulence genes (ciaB and pldA). A total of 48 samples (24 influent and 24 effluent) were collected at two WWTPs in southern Arizona in the United States, monthly from August 2011 to July 2012. Bacterial DNA extract was utilized for 16S rRNA metagenomic sequencing. Quantification of Arcobacter 16S rRNA gene was conducted using a recently developed SYBR Green-based quantitative PCR assay. Among 847 genera identified, 113 (13%) were identified as potentially pathogenic bacteria. Arcobacter 16S rRNA gene was detected in all influent samples and ten (83%) and nine (75%) effluent samples at each plant, respectively. Log reduction ratios of Arcobacter 16S rRNA gene in Plant A and Plant B were 1.7 &plusmn, 0.9 (n = 10) and 2.3 &plusmn, 1.5 (n = 9), respectively. The ciaB gene was detected by quantitative PCR in eleven (92%) and twelve (100%) of 12 influent samples from Plant A and Plant B, respectively, while the pldA gene was detected in eight (67%) and six (50%) influent samples from Plant A and Plant B, respectively. The prevalence of potentially pathogenic bacteria in WWTP effluent indicated the need for disinfection before discharge into the environment.

The effect of low dose irradiation on the chilled storage life of saucer scallops ( Amusium balloti ) was investigated. Scallops were packed in polythene bags and treated with doses of 1, 0.5, 1.5, and 3 kGy, then stored at 0°C. Sensory assessment indicated that nonirradiated scallops had a storage life of 13 d and this was extended to 18, 23 and 42 d when scallops were treated with 0.5, 1.5, and 3 kGy, respectively. Irradiation resulted in a 2 to 4 log reduction in bacterial numbers from an initial total viable count of 2.5 × 107/g. No irradiation-induced off-odors or off-flavors were detected, but a naturally occurring garlic-like off-flavor was reduced in intensity by irradiation treatment.

Background: Depletion of TCRαβ+ T cells and B cells with the CliniMACS Plus® has been used for haploidentical hematopoietic stem cell transplantation for a decade. The depletion procedure is time and labour demanding and with variable reported efficiencies. Recently, an automated procedure was launched for the CliniMACS Prodigy® (Miltenyi Biotec) but reported data are scarce. Here, we report the results of the first ten TCRαβ+ and B cell depletion procedures for clinical use performed at our centre. Materials and Methods: All transplants were from a parent to a child. Collection of peripheral blood stem cells was performed after filgrastim mobilisation by use of the Spectra Optia® (TerumoBCT) set on the MNC program. Because of insufficient hematopoietic stem cell mobilisation, 1 donor received additional plerixafor. Results: We performed ten uncomplicated processes with the CliniMACS Prodigy. We found the results of the depletion procedures satisfactory with a median log reduction of TCRαβ+ cells of –4.21 (range –3.98 to –4.74), resulting in a median number of TCRαβ+ cells in the depleted product of 28.6 × 103/kg recipient weight (range 14.9–69.7 × 103/kg). The median CD34 recovery was 83% (range 70–100). To achieve a sufficient number of CD34+ cells, we performed an additional CD34+ enrichment procedure using the CliniMACS Plus for 3 patients. The B cell depletion was slightly less efficient with a median log reduction of –3.72 (range –2.83 to –4.20). Conclusion: Overall, we found the TCRαβ and CD19 depletion procedure on the CliniMACS Prodigy easy to handle and reliable, providing reproducible good results.

Natural ultraviolet irradiance disinfection is known to play a significant role in both natural wastewater treatment systems and drinking water disinfection processes, while the influence of ultraviolet B (UVB) delivering method on sunlight disinfection outcome is still unclear. This study aims to determine the effects of environmentally relevant temperatures, UVB doses (J m−2) and dose rates (W m−2) on the inactivation and log reduction values (LRVs) of the F-RNA coliphage MS2 and Escherichia coli in optically clear water. E. coli and MS2 were separately incubated and irradiated at five different doses of UVB light that delivered using six UVB dose rates. The results of the study demonstrate that the UVB dose delivering method (combination of dose rate and exposure time) influences inactivation and LRVs of E. coli and MS2 at all UVB doses investigated (up to seven-fold difference). Two phases were identified within the UVB dose rate, UVB inactivation or LRV curves for both organisms; a UVB dose rate limited inactivation phase and a dose rate saturation inactivation phase. The results contribute to a better understanding of UVB disinfection in the environment and natural wastewater treatment systems, potentially improving the design and operation of high rate algal ponds.

Objective: The role of the inanimate environment in the transmission of healthcare-associated infections (HCAIs) is increasingly recognized. Hence, several self-disinfecting surfaces have gained attention as new infection control strategies. The objective of this study was to assess the antimicrobial efficacy of membrane-active polycation (maPK) surfaces against Staphylococcus aureus (S. aureus) applying the in vivo Galleria mellonella (G. mellonella) contamination model. Methods: In the first set-up maPK surfaces were contaminated with S. aureus and G. mellonella larvae were placed on the surface for 45 min. In the second set-up larvae were contaminated with S. aureus and transferred to maPK surfaces. Finally, the cross-over rates to larvae and maPK-surface were determined. Additionally, log reduction values (LRVs) of S. aureus on contaminated maPK and larvae were calculated. Results: The first experimental set-up revealed a significantly higher cross-over rate of S. aureus to the larvae from contaminated control surface (~2 x 103 colony forming untis (cfu)/mL) when compared to maPK surface (~5.1 x 101 cfu/mL). In the second set-up the cross-over rate of S. aureus from larvae to the control surface was significantly higher (~5.1 x 103 cfu/plate) than to the maPK surface (~2.1 x 101 cfu/plate). In both experiments LRVs were superior on maPK with 98.1% (p=0.0117) and 99.5% (p=0.0001) reduction, respectively. Conclusions: This in vivo study reveals the ability of maPK surfaces to reduce bacterial contamination and highlights the potential power to avoid cross-contamination from environmental surface.

Different parvoviruses are used interchangeably as models in validation studies to demonstrate effective clearance of small viruses by filtration in the manufacturing of biotherapeutics. The aim of these experiments was to determine if filtration of different parvoviruses (canine parvovirus [CPV], minute virus of mice [MVM], and porcine parvovirus [PPV]) results in similar virus retention. While filtration with a Planova™ 20 N filter (mean pore size: 19 ± 2 nm) completely removed PPV and MVM from the filtrate (mean log reduction factors [LRFs] ≥5.8 to ≥7.3 log10), CPV was only partly retained (3.6 log10) in a series of single and co-spike experiments. Additional co-spike experiments in 2 different feedstreams using 10 commercially available small pore filters confirmed these results; the LRF for CPV was around 2 log10 lower than for MVM and PPV. A sizing study using filters with mean pore sizes between 16.5 and 19 nm resulted in complete removal of CPV only with smaller pore sizes (17 and 16.5 nm). CPV behaves differently to MVM and PPV in viral filtration due to its apparent smaller size, suggesting CPV represents a worst-case model for other parvoviruses. Interpretation of efficacy and robustness of virus filtration thus depends on the choice of model virus.

Gaseous treatments with ClO2 and O3 on low-moisture foods (LMFs) have been reported for their efficient bacterial reduction without affecting the external quality of food. However, these studies were conducted on a small scale, which limits their application to LMF industries. We aimed to evaluate the effectiveness of gaseous antimicrobial intervention with ClO2 or O3 to reduce foodborne pathogens (Shiga toxin-producing Escherichia coli, serovars of Salmonella enterica, and Listeria monocytogenes) inoculated on almonds and peppercorns maintained under various conditions. Almonds were treated for over 4 or 6 h. Peppercorns were treated for over 2.5 or 4 h. Gaseous O3 treatment was used for 6 h on almonds and 2 or 4 h on peppercorns. Additionally, the effects of relative humidity (RH) during the treatment of peppercorns and post-treatment heating on almonds were evaluated. Heating at 65 °C post-ClO2 treatment yielded the highest bacterial log reduction of 4.6 CFU/g on almonds, while 80% RH resulted in 3.7-log bacterial reduction on peppercorns. Gaseous O3 resulted in maximum log reductions of 1.3 and 2.5 CFU/g on almonds and peppercorns, respectively. No visual damage was observed. In conclusion, ClO2 was more efficient than O3 and the treatment can be incorporated into industrial practices.

Peroxyacetic acid (PAA) is a commonly used antimicrobial in apple spray-bar interventions during post-harvest packing. However, limited information is available about its efficacy against foodborne pathogens on fresh apples under commercial packing conditions. In this study, the practical efficacies of PAA against Listeria monocytogenes on fresh apples during spray-bar operation at ambient and elevated temperature were validated in three commercial packing facilities using Enterococcus faecium NRRL B-2354 as a surrogate strain. Apples were inoculated with E. faecium at ~6.5 Log10 CFU/apple and subjected to PAA spray-bar interventions per commercial packing line practice. At each temperature and contact time intervention combination, 20–24 inoculated apples were processed together with 72–80 non-inoculated apples. Applying 80 ppm PAA at ambient temperature (17–21 °C) achieved a similar log reduction (P > 0.05) of E. faecium on Granny Smith apples (GSA) in three apple packing facilities, which caused 1.12–1.23 and 1.18–1.32 Log10 CFU/apple reductions of E. faecium on GSA for 30-sec and 60-sec intervention, respectively. Increasing the temperature of the PAA solution to 43–45 °C enhanced its bactericidal effect against E. faecium, causing 1.45, 1.86 and 2.19 Log10 CFU/apple reductions in three packing facilities for a 30-sec contact, and 1.50, 2.24, and 2.29 Log10 CFU/apple reductions for a 60-sec contact, respectively. Similar efficacies of PAA at both ambient and elevated temperature were also observed on Fuji apples. Spraying PAA on apples at ambient or elevated temperature reduced the level of E. faecium cross-contamination from inoculated apples to non-inoculated apples but could not eliminate cross-contamination. Data from this study provides valuable technical information and a reference point for the apple industry in controlling L. monocytogenes and verifying the effectiveness of their practices.

WOS: 000412662600004, PubMed ID: 27738866, The aim of this study was to compare the effects of widely used multipurpose contact lens solutions against Staphylococcus aureus and Pseudomonas aeruginosa, in addition to cystic and trophozoite forms of Acanthamoeba castellanii and A. polyphaga, that cause microbial keratitis. Three multipurpose solutions were tested: SOLO-care, ReNu, and Opti-Free Express. The test solutions were challenged with P. aeruginosa (ATCC 27853) and S. aureus (ATCC 2913) based on the ISO stand-alone and regiment test procedure for disinfecting products, A. polyphaga (ATCC 30871) and A. castellanii (1501/1A) cystic and trophozoite forms. Multipurpose solutions were sampled for surviving microorganisms at manufacturer's minimum recommended disinfection time. The number of viable organisms was determined, and log reductions were calculated. ReNu and SOLO-care resulted in a reduction greater than the required mean 3.0 logarithmic reduction against S. aureus, and SOLO-care and Opti-Free Express resulted in a reduction more than the required mean 3.0 logarithmic reduction against P. aeruginosa. Against the cystic and trophozoite forms of A. castellanii, the log reduction provided by SOLO-care was 1.01 and 1.31 log, respectively. ReNu provided a 0.83 log reduction of the cystic form and a 1.21 log reduction of the trophozoite form. Using Opti-Free Express, the log reduction for both forms was 1.31. SOLO-care led to a 0.61 log reduction of the cystic form of A. polyphaga and a 1.01 log reduction of the trophozoite form. ReNu provided a 0.41 log reduction of the cystic form and a 4.99 log reduction of the trophozoite form. Opti-free Express resulted in a 0.89 log reduction of the cystic form and a 3.11 log reduction of the trophozoite form. Multipurpose contact lens solutions using similar regimens can show different disinfection abilities.

The aim of this study was to evaluate the effects of gamma radiation on cherry tomatoes, to assess the potential of irradiation post-harvest treatment for fruit shelf-life extension. Freshly packed cherry tomatoes ( Solanum lycopersicu s var. cerasiforme ) were irradiated at several gamma radiation doses (0.8 kGy up to 5.7 kGy) in a 60 Co chamber. Microbiological parameters, antioxidant activity and quality properties such as texture, color, pH, total soluble solids content, titratable acidity, and sensory parameters, were assessed before and after irradiation and during storage time up to 14 days at 4 °C. Inactivation studies of natural cherry tomatoes microbiota and inoculated potential foodborne pathogens ( Salmonella enterica ; Escherichia coli and Staphylococcus aureus ) were performed. A two log reduction on the microbial load of cherry tomatoes was verified after irradiation at 3.2 kGy, and 14 days of storage at 4 °C. Moreover, a maximum reduction of 11 log on the viability of potential foodborne bacteria was obtained after irradiation at 3.2 kGy on spiked fruits. Regarding fruits quality properties, irradiation caused a decrease in firmness compared with non-irradiated fruit, although it was verified a similar acceptability among fruits non-irradiated and irradiated at 3.2 kGy. Therefore, these results suggest that the irradiation treatment could be advantageous in improving microbial safety of cherry tomatoes and shelf-life extension without affecting significantly its quality attributes. Industrial relevance There is an ever-increasing global demand from consumers for high-quality foods with major emphasis placed on quality and safety attributes. One of the main demands that consumers display is for minimally processed, high-nutrition/low-energy natural foods with no or minimal chemical preservatives. Extending the shelf-life, while improving the food safety, will have a positive impact on both the industry and consumers (and potential target groups such as immunocompromised patients). The present study indicated that post-harvest gamma radiation treatment of cherry tomatoes can be used as an emergent, clean and environmental friendly process to extend the shelf-life of this fruit with safety and quality.

Objectives: This pilot study of employing chlorine dioxide (CD) gas to disinfect gastrointestinal endoscopes was conducted to meet the expectations of many endoscopy units in China for a high-efficiency and low-cost disinfectant. Methods: An experimental prototype with an active circulation mode was designed to use CD gas to disinfect gastrointestinal endoscopes. One type of testing device composed of polytetrafluoroethylene (PTFE) tubes (2 m long, inner diameter 1 mm) and bacterial carrier containers was used to simulate the channel of the endoscope. PTFE bacterial carriers inoculated with Bacillus atrophaeus with or without organic burden were used to evaluate the sporicidal activity of CD gas. Factors including exposure dosage, relative humidity (RH), and flow rate (FR) influencing the disinfection effect of CD gas were investigated. Moreover, an autoptic disinfecting test on eight real gastrointestinal endoscopes after clinical use was performed using the experimental prototype. Results: RH, exposure dosage, organic burden, and the FR through the channel significantly (P

In this research, pasteurization of beer by nonthermal high pressure processing (HPP) and thermosonication (TS) were compared with thermal pasteurization. The inactivation of Saccharomyces cerevisiae ascospores in beer was studied and modelled for HPP at 200, 300 and 400 MPa, and for TS at 50, 55 and 60 °C with an acoustic energy density of 16.15 W/mL. The energy requirements for equivalent ascospore inactivation by HPP, TS, and thermal processes were compared. For the same processing time, ascospore inactivation was greatest with nonthermal HPP, followed by 60 °C TS, then 60 °C thermal processing. Nonlinear survival curves which could be described by the Weibull model were observed for both HPP and TS. To achieve a 2.5 log reduction in ascospores, HPP required 77 kJ/L compared with 189 kJ/L for thermal processing and 2612 kJ/L for TS. HPP and thermosonication may be alternatives to thermal beer pasteurization, achieving greater log reductions in S. cerevisiae ascospores with shorter processing times (TS and HPP) or less energy (HPP).

A process for manufacturing virally-safe porcine bone hydroxyapatite (HA) has been developed to serve as advanced xenograft material for dental applications. Porcine bone pieces were defatted with successive treatments of 30% hydrogen peroxide and 80% ethyl alcohol. The defatted porcine bone pieces were heat-treated in an oxygen atmosphere box furnace at 1,300°C to remove collagen and organic compounds. The bone pieces were ground with a grinder and then the bone powder was sterilized by gamma irradiation. Morphological characteristics such as SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy) images of the resulting porcine bone HA (THE Graft ® ) were similar to those of a commercial bovine bone HA (Bio-Oss ® ). In order to evaluate the efficacy of 1,300°C heat treatment and gamma irradiation at a dose of 25 kGy for the inactivation of porcine viruses during the manufacture of porcine bone HA, a variety of experimental porcine viruses including transmissible gastroenteritis virus (TGEV), pseudorabies virus (PRV), porcine rotavirus (PRoV), and porcine parvovirus (PPV) were chosen. TGEV, PRV, PRoV, and PPV were completely inactivated to undetectable levels during the 1,300oC heat treatment. The mean log reduction factors achieved were ≧4.65 for TGEV, ≧5.81 for PRV, ≧6.28 for PRoV, and ≧5.21 for PPV. Gamma irradiation was also very effective at inactivating the viruses. TGEV, PRV, PRoV, and PPV were completely inactivated to undetectable levels during the gamma irradiation. The mean log reduction factors achieved were ≧4.65 for TGEV, ≧5.87 for PRV, ≧6.05 for PRoV, and ≧4.89 for PPV. The cumulative log reduction factors achieved using the two different virus inactivation processes were ≧9.30 for TGEV, ≧11.68 for PRV, ≧12.33 for PRoV, and ≧10.10 for PPV. These results indicate that the manufacturing process for porcine bone HA from porcine-bone material has sufficient virus-reducing capacity to achieve a high margin of virus safety.

Hot water sanitization is a common means to maintain microbial control in process equipment for industries where microorganisms can degrade product or cause safety issues. This study compared the hot water inactivation kinetics of planktonic and biofilm-associated Sphingomonas parapaucimobilis at temperatures relevant to sanitization processes used in the pharmaceutical industry, viz. 65, 70, 75, and 80°C. Biofilms exhibited greater resistance to hot water than the planktonic cells. Both linear and nonlinear statistical models were developed to predict the log reduction as a function of temperature and time. Nonlinear Michaelis-Menten modeling provided the best fit for the inactivation data. Using the model, predictions were calculated to determine the times at which specific log reductions are achieved. While ≥80°C is the most commonly cited temperature for hot water sanitization, the predictive modeling suggests that temperatures ≥75°C are also effective at inactivating planktonic and biofilm bacteria in timeframes appropriate for the pharmaceutical industry.