ultraviolet-C Irradiation Research Articles

Dry biofilms on polystyrene surfaces: the role of oxidative treatments for their mitigation

Candida auris and Staphylococcus aureus are associated with a wide range of infections, as they exhibit multidrug resistance – a growing health concern. In this study, gaseous ozone, and ultraviolet-C (UVC) radiation are applied as infection control measures to inactivate dry biofilms of these organisms on polystyrene surfaces. The dosages utilised herein are 1000 and 3000 ppm.min for ozone and 2864 and 11592 mJ.cm−2 for UVC. Both organisms showed an increased sensitivity to UVC relative to ozone exposure in a bespoke decontamination chamber. While complete inactivation of both organisms (>7.5 CFU log) was realized after 60 mins of UVC application, this could not be achieved with ozonation for the same duration. However, a combined application of ozone and UVC yielded complete inactivation in only 20 mins. For both treatment methods, it was observed that dry biofilms of S. aureus were more difficult to inactivate than dry biofilms of C. auris. Compared to dry biofilms of C. auris, micrographs of wet C. auris biofilms revealed the presence of an abundance of extracellular material after treatments. Interestingly, wet biofilms were more difficult to inactivate than dry biofilms. These insights are crucial to preventing recalcitrant and recurrent infections via contact with contaminated polymeric surfaces.

Influence of ultraviolet-C irradiation treatment on quality and shelf life of mung bean sprouts during storage

This research analyzed the impact of exposing mung bean sprouts to ultraviolet-C (UV-C) radiation for different periods (2, 5, and 10 min). Treated sprouts were preserved at 5°C and 85-95% relative humidity for 6 days. Irradiation for 10 min effectively reduced fresh weight loss, electrolyte leakage, and microbial count and main-tained the firmness of sprouts. It also positively influenced the bioactive components, including antioxidants, total phenols, and protein, potentially providing health benefits to consumers. In addition, prolonged UV-C exposure for 10 min leads to oxidative stress, marked by a rise in malondialdehyde, proline, and hydrogen peroxide content. These compounds assist in stress reduction and preserve secondary metabolites. This research implies that post-harvest 10 min UV-C irradiation offers a potential approach to uphold quality while maximizing the nutritional value of mung bean sprouts.

The effect of UV-C radiation and cytokinin on pea plants

Aim. The effect of ultraviolet C (UV-C) radiation and cytokinin benzylaminopurine (BAP) on the growth and content of photosynthetic pigments in leaves of pea plants (Pisum sativum L.) was studied. Methods. Pea plants cultivar Aronis were irradiated by UV-C at a dose of 15 kJ/m2 with a power of 7 W/m2. Part of the non-irradiated plants was treated with BAP, part of the plants was treated with BAP one day before irradiation and part of plants were treated with BAP in one day after UV-C irradiation. Length and mass of plant shoots and roots were measured during the experiment. Content of photosynthetic pigments in leaves were determined during all time the experiment. Results. It was shown that pea plants growth delayed content of carotenoids in leaves reduced after the UV-C radiation of pea plants. Treatment of plants with BAP after the end of the UV-C radiation accelerated the restoration of photosynthetic pigments content. Conclusions. It was shown that UV-C radiation of pea plants by dose of 15 kJ/m2 caused inhibition of growth, decreasing photosynthetic pigments content in leaves. The BAP treatment after radiation stimulated the restoration of photosynthetic pigments content in the leaves.

Evaluating the Impact of UVC Exposure on Forage Maize Seeds under Hydroponic Condition

Background: UV radiation, with shorter wavelengths than visible light, plays a pivotal role in stimulating growth processes and boosting the synthesis of beneficial compounds in plants. Moreover, it triggers morphological changes and genetic responses, shaping plants’ physical traits and adaptability. Nevertheless, a nuanced understanding is necessary as excessive UV exposure can also cause harm, underscoring the complexity of the relationship between UV radiation and plants. The study aimed to evaluate the effect of ultraviolet C (UVC) light exposure on the germination and growth of forage maize seeds under controlled conditions in an indoor crop. One sample of seeds was exposed to UVC light, while the other was not. Methods: The experiment was carried out for 14 days, with the plants subjected to mixed blue-red light, fertigation and kept at a maximum external temperature of 30°C and maximum internal temperature of 25.1°C. UVC light is applied for 10 minutes to the seeds before germination. Result: The results showed that the plants exposed to UVC light had an average growth increase of 3cm compared to those that did not receive the treatment. However, the protein content of both sets of seedlings was similar. The study suggests that further research is necessary to determine the optimal duration and distance for UVC exposure to minimize any potential negative effects on the plants. It also highlights the need to investigate the effect of UVC radiation on the nutritional content of hydroponic crops to ensure that the increased growth does not come at the expense of nutritional quality. The experiment was carried out in Medellin, Colombia, with a maximum solar radiation of 1000 W/m2 and an altitude of 1500 meters. Overall, the study provides evidence that UVC radiation can enhance the growth of hydroponic maize seedlings, but more research is needed to fully understand its effects. At the end, there is an improvement in the growth of forage corn in seeds that have been subjected to UVC light compared to those that have not. It is worth highlighting the need for more research on changes in nutritional components in general.

Surface Cleaning with a Microfiber Cloth and Water followed by Ultraviolet-C Light Exposure Achieves Non-Inferior Disinfection of a Pathogenic Staphylococcus aureus Strain versus Use of Germicidal Wipes.

We hypothesized that ultraviolet-C (UV-C) irradiation (Surfacide, Waukesha, WI) following use of microfiber cloths (Sanny Shop LLC, Longmont, CO) soaked in waterwould be noninferior to surface disinfection wipes containing a quaternary ammonium compound and alcohol (PDI Healthcare, Woodcliff Lake, NJ)for the pathogenic Staphylococcus aureus (S. aureus) sequence type 5 (ST5). This was a randomized laboratory study of disinfection approaches for S. aureusST5. A total of 270 polycarbonate slides loaded with ST5 were prepared for the standard surface disinfection group (N=18) and water-soaked microfiber cloths and UV-C treatment group (N=144), along with positive and negative microbiological controls. All 18 samples of S. aureus ST5 bacteria treated with standard chemical wipes showed complete disinfection (colony forming units (CFU) = 0). All 144 treatments with water-soaked microfiber wipes followed by UV-C exposure showed complete disinfection (CFU =0) regardless of soiling, height from the floor, or orientation to the emitters. The upper 95% exact one-sided confidence limit for any CFU >0 was 2.1%. These data affirm our hypothesis that surface wiping with a damp cloth followed by triangular UV-C irradiation delivery is noninferior to surface disinfection for S. aureusST5 using germicidal wipes, even when UV-C is compromised by height from the floor and orientation to the emitters and surface disinfection is targeted. Removing bioburden with chemical-free microfiber cloths followed by triangular UV-C delivery is a noninferior strategy to targeted surface disinfection with chemical disinfecting wipes for the pathogenicS. aureusST5 strain in the laboratory setting.

Thermoluminescence and ATR-FTIR study of UVC-irradiated low-density polyethylene (LDPE) food packaging

This research aims to study the effects of ultraviolet C (UVC) radiation on low-density polyethylene (LDPE) food packaging. Main objectives include evaluating LDPE degradation and detecting UVC radiation using thermoluminescent dosimeters (TLDs) placed under LDPE samples. Results confirm accurate UVC detection after one hour of exposure, providing a useful tool for optimize food treatment procedures.ATR-FTIR spectroscopy analysis revealed subtle alterations (<8 % transmittance relative) in UVC-irradiated LDPE samples, including possible CH breakage (2910 and 2848 cm−1) and potential CC bond vibrations (1470 cm−1), among others. However, observed variations may stem from LDPE properties rather than entirely from UVC radiation. A comparative study of UVC-induced thermoluminescence (TL) emissions provided insights into various TLDs materials. TL kinetic analysis, using computerised glow curve deconvolution (CGCD) method, unveiled trap charge activation due to UVC exposure, including partial ionization, bleaching effect and photo-transfer (PTTL) processes. LDPE samples amplified UVC-TL responses, revealing intensity differences between the TLDs attributed to the PTTL process, accentuated by the lack of an annealing treatment. Additionally, chemical composition of the TL detectors such as, type, concentration, number, oxidation states and ionic radii of their dopants may influence UVC-TL response. Consequently, TL intensity ratios follow as: GR-200 (LiF: Mg, Cu, P) > TLD-100 (LiF: Ti, Mg) > TLD-400 (CaF2: Mn) > TLD-200 (CaF2: Dy). Thus, GR-200 detects ionizing radiation but cannot distinguish between ionizing and non-ionizing UVC radiation, while TLD-100 has limited effectiveness as a UVC radiation detector. In contrast, TLD-400 is suitable for detecting UVC radiation and TLD-200 emerges as the most favorable UVC detector, showing consistent response levels and minimal PTTL effect placed under the LDPE samples without the need of a thermal annealing treatment that makes the TLD-200 to be reusable in a low-cost measurement protocol.

Impact of Ultraviolet-C Exposure and Mechanical Stress on Conidium Production in Corynespora cassiicola Isolates From Cotton and Soybean

The procurement of inoculum for bioassays with target spot, a significant disease in cotton and soybeans, caused by Corynespora cassiicola can be hindered by the low production of conidia on artificial culture media. The study aimed to determine whether mechanical stress on the mycelium and exposure to ultraviolet-C (UV-C) radiation for varying durations could enhance conidial production in C. cassiicola isolates. Eight isolates from cotton and soy were used, grown in V8 juice medium. After five days of incubation in a climate-controlled chamber, each isolate either underwent mycelium scraping or remained unscraped and was subsequently exposed to UV-C radiation for either 1.0, 1.5 or 2.0 min, in comparison to a control group with zero UV exposure time. Following these procedures, conidial suspensions from each isolate were obtained and quantified (conidia per mL) using a Neubauer chamber The ISO 3S and ISO 4S isolates were found to produce more conidia than the other isolates, regardless of whether they were subjected to mycelium scraping or exposure to UV-C radiation. For most isolates, exposure to UV-C radiation for 1.0-1.5 min led to increased conidium production. Generally, it was not feasible to discern differences in conidial production with respect to the mycelium scraping process. Nevertheless, exposure to UV-C radiation for 1.0 min can be used to induce conidium production in C. cassiicola isolates.

Full-length GSDME mediates pyroptosis independent from cleavage.

Gasdermin (GSDM) family proteins, known as the executors of pyroptosis, undergo protease-mediated cleavage before inducing pyroptosis. We here discovered a form of pyroptosis mediated by full-length (FL) GSDME without proteolytic cleavage. Intense ultraviolet-C irradiation-triggered DNA damage activates nuclear PARP1, leading to extensive formation of poly(ADP-ribose) (PAR) polymers. These PAR polymers are released to the cytoplasm, where they activate PARP5 to facilitate GSDME PARylation, resulting in a conformational change in GSDME that relieves autoinhibition. Moreover, ultraviolet-C irradiation promotes cytochrome c-catalysed cardiolipin peroxidation to elevate lipid reactive oxygen species, which is then sensed by PARylated GSDME, leading to oxidative oligomerization and plasma membrane targeting of FL-GSDME for perforation, eventually inducing pyroptosis. Reagents that concurrently stimulate PARylation and oxidation of FL-GSDME, synergistically promoting pyroptotic cell death. Overall, the present findings elucidate an unreported mechanism underlying the cleavage-independent function of GSDME in executing cell death, further enriching the paradigms and understanding of FL-GSDME-mediated pyroptosis.

Optimized Ultraviolet-C Processing Inactivates Pathogenic and Spoilage-Associated Bacteria while Preserving Bioactive Proteins, Vitamins, and Lipids in Human Milk.

Holder pasteurization (HoP) enhances donor human milk microbiological safety but damages many bioactive milk proteins. Though ultraviolet-C irradiation (UV-C) can enhance safety while better preserving some milk proteins, it has not been optimized for dose or effect on a larger array of bioactive proteins. We determined the minimal UV-C parameters that provide >5-log reductions of relevant bacteria in human milk and how these treatments affect an array of bioactive proteins, vitamin E, and lipid oxidation. Treatment at 6000 and 12 000 J/L of UV-C resulted in >5-log reductions of all vegetative bacteria and bacterial spores, respectively. Both dosages improved retention of immunoglobulin A (IgA), IgG, IgM, lactoferrin, cathepsin D, and elastase and activities of bile-salt-stimulated lipase and lysozyme compared with HoP. These UV-C doses caused minor reductions in α-tocopherol but not γ-tocopherol and no increases in lipid oxidation products. UV-C treatment is a promising approach for donor human milk processing.

Ultraviolet-C (UV-C) Effectiveness for Bacterial Decontamination in The Hospital Setting: A Systematic Review

Introduction: Bacteria are the most common agent reported to cause hospital-acquired infection (HAI) and nurses play a key role in achieving optimal decontamination. Ultraviolet-C (UV-C) is a promising candidate to reduce the bacteria infection burden. Therefore, this review aims to explore the UV-C application and its effectiveness in reducing bacteria contamination on various objects that can act as sources of HAI transmission. Methods: Searches were conducted on the PubMed, ScienceDirect, Scopus, and Cumulative Index to Nursing and Allied Health Literature databases. The inclusion criteria were randomized clinical trials, and non-randomized clinical intervention studies, written in English and published between January 2018 and March 2023. The search strategy used a population (P), intervention (I), comparator (C), and outcome (O) approach. Results: A total of 21 eligible studies were included in this review with four being related to decontaminating medical devices, two to personal equipment, nine to communication devices, and the remaining six to the environment. The exposure to UV-C radiation varies ranging from 24 s to 24 h (continuously) and it reduced the level of bacteria even up to 100%. Meanwhile, previously the objects were detected to be contaminated with pathogenic and resistant bacteria. Conclusion: UV-C exposure can be effectively used to decontaminate various objects in hospitals. However, special consideration should be given to semi-critical devices due to contact with mucosal tissue. Further studies are needed regarding the application of doses and duration of UV-C exposure to eliminate bacteria completely.

Far-UVC (222 nm) irradiation effectively inactivates ssRNA, dsRNA, ssDNA, and dsDNA viruses as compared togermicidal UVC (254 nm).

Ultraviolet-C (UVC) irradiation is being used as an effective approach for the disinfection of pathogenic viruses present in air, surfaces, and water. Recently, far-UVC radiation (222 nm) emitted by KrCl* (krypton-chloride) excimer lamps have been recommended for disinfecting high-risk public spaces to reduce the presence and transmission of infectious viruses owing to limited human health exposure risks as compared to germicidal UVC (254 nm). In this study, the UVC inactivation performances of individual filtered KrCl* excimer lamp (222 nm) and germicidal UVC lamp (254 nm) were determined against four viruses, bacteriophages MS2, Phi6, M13, and T4, having different genome compositions (ssRNA, dsRNA, ssDNA and dsDNA, respectively) and shapes (i.e., spherical (Phi6), linear (M13), and icosahedral (MS2 and T4)). Here, the disinfection efficacies of filtered KrCl* excimer lamp (222 nm) and germicidal UVC lamp (254 nm) were evaluated for highly concentrated virus droplets that mimic the virus-laden droplets released from the infected person and deposited on surfaces as fomites. Filtered KrCl* excimer (222 nm) showed significantly better inactivation against all viruses having different genome compositions and structures compared to germicidal UVC (254 nm). The obtained sensitivity against the filtered KrCl* excimer (222 nm) was found to be in the order, T4 > M13 > Phi6 > MS2 whereas for the germicidal UVC (254 nm) it was T4 > M13 > MS2 > Phi6. These results provide a strong basis to promote the use of filtered KrCl* excimer lamps (222 nm) in disinfecting contagious viruses and to limit the associated disease spread in public places and other high-risk areas.

Combined hurdle effects of pulsed electric field and ultraviolet-C irradiation on microbial load reduction and composition of hemeproteins from Asian seabass gills

The combined effects of two non-thermal technologies, namely pulsed electric field (PEF) and ultraviolet-C (UV–C) irradiation, on microbial load reduction and composition of crude hemeprotein extract (CHPE) from Asian seabass gills were investigated. PEF at two intensities (15 kV and 17.5 kV) for different times (0, 1, 2.5, 5 and 10 min) was employed to treat CHPE solution. Subsequently freeze-dried PEF treated powders were exposed to UV-C for varying durations (0, 15 and 30 min). Microbial community in gill and selected CHPE powders was also determined using next generation sequencing (NGS). PEF treatment effectively reduced the initial microbial load (8.0 log10 CFU/g) when high PEF intensity (17.5 kV) for longer treatment time (5 min) was employed, leading to microbial load reduction to 5.5 log10 CFU/g. However, prolonged PEF treatment adversely affected CHPE properties, as witnessed by the decreased heme iron content and alterations in protein patterns. Subsequent UV-C irradiation of freeze-dried PEF-treated CHPE powder for 15 min demonstrated a synergistic effect on further reduction of microbial counts to 3.0 log10 CFU/g. NGS analysis showed the dominance of Flavobacteriaceae families in the microbial community composition in gill, untreated CHPE powder and PEF-UV-C treated CHPE powder. Nevertheless, no Vibrio parahaemolyticus and other Vibrio spp. were detected in all samples. The study revealed the potential of combined non-thermal hurdle technologies, under appropriate conditions, in ensuring microbiological safety and maintaining quality of CHPE. CHPE powder could therefore be used for fortification in food products as an iron supplement to alleviate iron-deficient anemia.

Pilot randomized experimental study evaluating isopropyl alcohol and ultraviolet-C radiation in the disinfection of healthcare workers' smartphones

Smartphones in medical settings pose infection risks due to harbouring pathogenic bacteria. This pilot study assessed the effectiveness duration of sanitization methods, focusing on 70% isopropyl alcohol wipes and ultraviolet-C (UVC) boxes, aiming to obtain preliminary data on the reduction in total bacterial load 3h post-sanitization. A randomized monocentric trial with two intervention arms (wipes and UVC boxes) was designed. As participants, healthcare workers from three wards at Fondazione Policlinico Universitario 'A. Gemelli' IRCCS Hospital were recruited, stratified by ward, and block randomized within each ward to control confounders. Seventy-one healthcare workers, mostly nurses (62%) were included in the study. Initial bacterial load reduction was significant with both disinfection techniques, but after 3h both methods showed increased bacterial levels, with wipes displaying potentially higher residual efficacy (P=0.056). To adequately size a trial (89% power, significance level 0.05) for assessing the residual efficacy of alcohol-impregnated wipes compared with UVC boxes at 3h post-sanitization, 503 professionals per group were required. This study highlights the necessity for guidelines on hospital smartphone sanitization and educational initiatives for healthcare workers and patients. Further studies, adequately sized, are necessary to determine optimal sanitization intervals and assess pathogen transmission risks.

Ultraviolet C radiation on polypropylene: A potential way to reduce plastic pollution

This study investigates the application of ultraviolet C (UVC) radiation to extend the lifetime of healthcare items containing polypropylene (PP), particularly personal protective equipment (PPE). The main objectives involve assessing possible PP damage from UVC exposure and detecting UVC treatment within PP samples. FTIR spectroscopy and Raman spectroscopy reveal slight degradation in UVC-irradiated PP samples, demonstrating resilience post-treatment. Investigations using commercial thermoluminescence dosimeters (TLD-100, TLD-200, TLD-400 and GR-200) positioned under varying thicknesses of PP (0.20 and 0.80 mm) identify TLD-100 as a promising UVC detector. Conversely, TLD-200 and TLD-400 do not prove to be effective detectors, exhibiting similar behavior to the dosimeters without a plastic sample. And GR-200 does not possess the capability to differentiate between ionizing and non-ionizing components of UVC radiation. This research emphasizes the role of UVC to prolong the lifetime of healthcare items containing PP, thus aiding in efforts to reduce plastic pollution.

Valorization of ultraviolet-C (UV-C) dose validation in spices

In this work, ultraviolet-C (UV-C) radiation was applied at dose levels of 0, 0.5, 1, 1.5 and 2.0 kJ.m–2 to evaluate changes on the antioxidant capacity of dried fennel seeds, chilli pepper, and coriander seeds powder during storage. The samples’ total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydra-zyl activity, and ferric-reducing antioxidant power (FRAP) were evaluated prior to and after storage for 6 and 12 months at 25°C and a relative humidity of 45%. The results showed that spices treated with UV-C doses had significantly greater content of TPC, TFC and FRAP during storage, compared to untreated samples. The validation of UV-C dose, as investigated by the partial least squares regression analysis, stated the most valid dose for each dried spice that improved its phenolic content and antioxidant activity prior to and after storage. These findings revealed that UV-C irradiation could help alleviate losses and sustain spices’ quality and shelf life as a postharvest treatment method.

Identification and Measurement of Biomarkers at Single Microorganism Level for In Situ Monitoring Deep Ultraviolet Disinfection Process.

Since the COVID-19 disease has been further aggravated, the prevention of pathogen transmission becomes a vital issue to restrain casualties. Recent research outcomes have shown the possibilities of the viruses existing on inanimate surfaces up to few days, which carry the risk of touch propagation of the disease. Deep ultraviolet germicide irradiation (UVGI) with the wavelength of 255-280nm has been verified to efficiently disinfect various types of bacteria and virus, which could prevent the aggravation of pandemic spread. Even though considerable experiments and approaches have been applied to evaluate the disinfection effects, there are only few reports about how the individual bio-organism behaves after ultraviolet C (UVC) irradiation, especially in the aspect of mechanical changes. Furthermore, since the standard pathway of virus transmission and reproduction requires the host cell to assemble and transport newly generated virus, the dynamic response of infectious cell is always the vital aspect of virology study. In this work, high power LEDs array has been established with 270nm UVC irradiation to evaluate disinfection capability on various types of bio-organism, and incubator embedded atomic force microscopy (AFM) is used to investigate the single bacterium and virus under UVGI. The real-time tracking of the living Vero cells infected with adenovirus has also been presented in this study. The results show that after sufficient UVGI, the outer shell of bacteria and viruses remain intact in structure, however the bio-organisms lost the capability of reproduction and normal metabolism. The experiment results also indicate that once the host cell is infected with adenovirus, the rapid production of newborn virus capsid will gradually destroy the cellular normal metabolism and lose mechanical integrity.

Effect of UV-C Treatment on Shelf Life of Soft Wheat Bread (Bun).

The effect of exposure of soft wheat buns to Ultraviolet-C radiation (UV-C, 253.7 nm) was studied as an alternative to conventional treatments to control fungal spoilage and prolong shelf life. To identify the most suitable operating conditions, the study included preliminary tests on the permeability of films to UV-C irradiation, and on treatment antifungal efficacy on target microorganisms (Penicillium digitatum and Saccharomycopsis fibuligera) in Petri dishes. A 125 µm T9250B film (Cryovac® Sealed Air S.r.l), commercially available for long-life bread treated with ethanol and conditioned in a modified atmosphere, was selected to pack buns before the UV-C treatment. The study was carried out along with the observation of the fungal growth of buns artificially inoculated with suspensions of P. digitatum and S. fibuligera, treated under UV-C at a distance of 25 cm between bread and the 15 W UV-C source, in comparison to untreated buns used as control. Estimation of fungal growth as well as sensory evaluation was made 2, 4, 7, 10 and 14 days after the treatment. UV-C treated buns showed a noticeable reduction of fungal spoilage and kept a tender texture for up to two weeks after packaging. UV-C treatment represents a good opportunity for the bakery industry, reducing costs and ensuring a prolonged shelf life of a commercial product, respecting the health and hedonistic expectations of the customers.

Investigating the Impact of UV-C Radiation on the Mechanical Characteristics of Semifinished Potato Tubers Prepared from Varied Potato Cultivars

The relationship between various characteristics of postharvest vegetables and their corresponding biological surface properties is strongly interconnected, leading to a broad spectrum of properties after irradiation. The primary objective of the present study was to investigate how different doses of Ultraviolet-C (UV-C) radiation affect the mechanical properties of semifinished potato tubers derived from distinct Polish varieties, namely, Innovator, Fineziya, and Victoria. A low UV-C dose ranging from 0 to 30 mJ/cm2 was administered. The Innovator variety, when subjected to irradiation, exhibited the highest levels of compression force, cutting force, and bending force. Additionally, the irradiated samples demonstrated improved resistance to compression force, bending force, and increased weight compared to the control samples. Conversely, the control samples exhibited higher resistance to cutting load than the irradiated ones in all varieties. The analysis of variance confirmed a significant difference in compression, cutting force, and tuber weight among the treatment samples in all varieties. Furthermore, stress-strain analyses were performed and showed an elastic behavior of the Victoria variety and a higher Young’s modulus for the Innovator variety.

A proof-of-principle for decontamination of transplantation kidney through UV-C exposition of the perfusate solution

Kidney transplantation is a common yet highly demanding medical procedure worldwide, enhancing the quality of life for patients with chronic kidney disease. Despite its prevalence, the procedure faces a shortage of available organs, partly due to contamination by microorganisms, leading to significant organ disposal. This study proposes utilizing photonic techniques associated with organ support machines to prevent patient contamination during kidney transplantation. We implemented a decontamination system using ultraviolet-C (UV-C) irradiation on the preservation solution circulating through pigs' kidneys between harvest and implant. UV-C irradiation, alone or combined with ultrasound (US) and Ps80 detergent during ex-vivo swine organ perfusion in a Lifeport® Kidney Transporter machine, aimed to reduce microbiological load in both fluid and organ. Results show rapid fluid decontamination compared to microorganism release from the organ, with notable retention. By including Ps80 detergent at 0.5% during UV-C irradiation 3 log10 (CFU mL−1) of Staphylococcus aureus bacteria previously retained in the organ were successfully removed, indicating the technique's feasibility and effectiveness.

Enhancing Raw Bovine Milk Quality using Ultraviolet-C (UV-C) Irradiation: A Microbial and Lipid Peroxidation Study.

This study investigated the efficacy of ultraviolet-C (UV-C) irradiation in enhancing the quality of raw bovine milk by targeting microbial populations and lipid peroxidation, both of which are key factors in milk spoilage. We categorized the raw milk samples into three groups based on initial bacterial load: low (<3 Log 10 CFU/mL), medium (3-4 Log 10 CFU/mL), and high (>4 Log 10 CFU/mL). Using a 144 W thin-film UV-C reactor, we treated the milk with a flow rate of 3 L/min. We measured the bacterial count including standard plate count, coliform count, coagulase-negative staphylococci count, and lactic acid bacteria count and lipid peroxidation (via thiobarbituric acid reactive substances assay) pre- and post-treatment. Our results show that UV-C treatment significantly reduced bacterial counts, with the most notable reductions observed in high and medium initial load samples (>4 and 3-4 Log 10 CFU/mL, respectively). The treatment was particularly effective against coliforms, showing higher reduction efficiency compared to coagulase-negative staphylococci and lactic acid bacteria. Notably, lipid peroxidation in UV-C treated milk was significantly lower than in pasteurized or untreated milk, even after 72 hours. These findings demonstrate the potential of UV-C irradiation as a pre-treatment method for raw milk, offering substantial reduction in microbial content and prevention of lipid peroxidation, thereby enhancing milk quality.