Foodborne Pathogen Inactivation by Cold Plasma Reactive Species

Cold plasma is implemented in the food industry for protecting the agricultural product from foodborne pathogens. In this case, dielectric barrier discharge cold plasma pen (DBD-CP) was applied to study its efficiency in inactivation of bacterial on oyster mushroom. The surface of the fresh oyster mushroom was treated with 5 kV of AC voltage with variable of treatment times (0-4 min). Data showed sufficient energy by DBD-CPP has inactivated the existence of bacterial on the oyster mushroom surface with undetectable of bacteria colony. The reactive species generated by cold plasma undoubtedly irreversibly damage the deoxyribonucleic acid, ribonucleic acid, and enzymes of gram bacterial, which eventually causes cell death. Above all, an understanding of the microorganism cell structure, the food surface types, and roughness is an essential in manipulating cold plasma processing parameters to achieve the maximum rate of microbial inactivation.

Virucidal efficacy of guanidine-free inactivants and rapid test buffers against SARS-CoV-2

A pathogen inactivation step during collection or processing of clinical samples has the potential to reduce infectious risks associated with diagnostic procedures. It is essential that these inactivation methods are demonstrated to be effective, particularly for non-traditional inactivation reagents or for commercial products where the chemical composition is undisclosed. This study assessed inactivation effectiveness of twenty-four next-generation (guanidine-free) nucleic acid extraction lysis buffers and twelve rapid antigen test buffers against SARS-CoV-2, the causative agent of COVID-19. These data have significant safety implications for SARS-CoV-2 diagnostic testing and support the design and evidence-based risk assessment of these procedures.

The 4-Year Experience with Implementation and Routine Use of Pathogen Inactivation in a Brazilian Hospital

(1) Background: We reviewed the logistics of the implementation of pathogen inactivation (PI) using the INTERCEPT Blood System™ for platelets and the experience with routine use and clinical outcomes in the patient population at the Sírio-Libanês Hospital of São Paulo, Brazil. (2) Methods: Platelet concentrate (PC), including pathogen reduced (PR-PC) production, inventory management, discard rates, blood utilization, and clinical outcomes were analyzed over the 40 months before and after PI implementation. Age distribution and wastage rates were compared over the 10 months before and after approval for PR-PC to be stored for up to 7 days. (3) Results: A 100% PR-PC inventory was achieved by increasing double apheresis collections and production of double doses using pools of two single apheresis units. Discard rates decreased from 6% to 3% after PI implementation and further decreased to 1.2% after 7-day storage extension for PR-PCs. The blood utilization remained stable, with no increase in component utilization. A significant decrease in adverse transfusion events was observed after the PI implementation. (4) Conclusion: Our experience demonstrates the feasibility for Brazilian blood centers to achieve a 100% PR-PC inventory. All patients at our hospital received PR-PC and showed no increase in blood component utilization and decreased rates of adverse transfusion reactions.

Mapping of UV-C dose and SARS-CoV-2 viral inactivation across N95 respirators during decontamination

During public health crises like the COVID-19 pandemic, ultraviolet-C (UV-C) decontamination of N95 respirators for emergency reuse has been implemented to mitigate shortages. Pathogen photoinactivation efficacy depends critically on UV-C dose, which is distance- and angle-dependent and thus varies substantially across N95 surfaces within a decontamination system. Due to nonuniform and system-dependent UV-C dose distributions, characterizing UV-C dose and resulting pathogen inactivation with sufficient spatial resolution on-N95 is key to designing and validating UV-C decontamination protocols. However, robust quantification of UV-C dose across N95 facepieces presents challenges, as few UV-C measurement tools have sufficient (1) small, flexible form factor, and (2) angular response. To address this gap, we combine optical modeling and quantitative photochromic indicator (PCI) dosimetry with viral inactivation assays to generate high-resolution maps of “on-N95” UV-C dose and concomitant SARS-CoV-2 viral inactivation across N95 facepieces within a commercial decontamination chamber. Using modeling to rapidly identify on-N95 locations of interest, in-situ measurements report a 17.4 ± 5.0-fold dose difference across N95 facepieces in the chamber, yielding 2.9 ± 0.2-log variation in SARS-CoV-2 inactivation. UV-C dose at several on-N95 locations was lower than the lowest-dose locations on the chamber floor, highlighting the importance of on-N95 dose validation. Overall, we integrate optical simulation with in-situ PCI dosimetry to relate UV-C dose and viral inactivation at specific on-N95 locations, establishing a versatile approach to characterize UV-C photoinactivation of pathogens contaminating complex substrates such as N95s.

Inactivation of Salmonella enterica serovar Typhimurium and Staphylococcus aureus in rice by radio-frequency heating

The objectives of this study were to determine the effect of the milling degree (MD) of Oryza sativa L. (Korean rice) on the heating rate, pathogen inactivation (Salmonella Typhimurium and Staphylococcus aureus), and color change resulting from radio-frequency (RF) heating. Rice samples inoculated with pathogens were placed in a polypropylene jar and subjected to RF heating for 0-75 s. The heating rate of rice with a 2% MD was the highest during RF heating, followed by those with a 0, 8, and 10% MD, and the reduction of pathogens showed the same trend. The reduction of the levels of pathogens in rice with a MD 0 and 2% was significantly higher than that observed for rice with a MD of 8 and 10% under the same treatment conditions. For example, log reductions of S. Typhimurium in rice by 55 s RF heating were 3.64, 5.19, 2.18, and 1.80 for milling degree of 0, 2, 8, and 10%, respectively. At the same treatment conditions, log reduction of S. aureus were 2.77, 5.08, 1.15, and 0.90 for milling degree of 0, 2, 8, and 10%, respectively. The color of rice measured according to L*, a*, and b* was not significantly altered after RF heating, regardless of the MD. Therefore, the MD of rice should be considered before RF heating is applied to inactivate foodborne pathogens.