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Strawberry powdery mildew caused by Podosphaera aphanis, one of the most important diseases affecting strawberry production in Japan, can be effectively controlled by supplemental ultraviolet (UV) irradiation. Here, we investigated disease severity on plants irradiated with UV light at 270–380 nm with/without inoculation and demonstrated significant decreases in disease severity on the UV‐treated plants throughout almost all of the experiment periods. Daily UV irradiation for 3 hr (0.17–0.96 kJ ⋅m−2 ⋅day−1) significantly reduced the incidence of powdery mildew on UV‐treated strawberry at day 58 after initiation of UV irradiation in a natural infection and at day 168 in artificial inoculation tests compared with non‐UV‐treated controls. Furthermore, we found that two pathogenesis‐related protein (PR) genes were up‐regulated 7 days after initiation of UV irradiation on plants before or after transplantation into raised beds. Transcript levels of five defence‐response genes were estimated using quantitative reverse transcription PCR to determine whether UV irradiation induced a defence response; PR‐3 and PR‐5 transcripts were significantly higher in the UV‐treated strawberry leaves after UV irradiation than in the non‐irradiated controls. In addition, transcript levels of both genes were significantly up‐regulated in plants irradiated with a higher radiant dose (0.90–0.96 kJ ⋅m−2 ⋅day−1) within 7 days after initiation of UV treatment, compared with plants exposed to a lower dose (0.17 kJ ⋅m−2 ⋅day−1) and with controls. Thus, PR‐3 and PR‐5 are induced in strawberry leaves as part of a defence response that is induced by UV irradiation. [ABSTRACT FROM AUTHOR]

Background: Contaminated environmental surfaces are important sources of transmission for healthcare-associated pathogens, including Clostridioides (Clostridium) difficile. The effectiveness of manual bleach cleaning and pulsed xenon ultraviolet (PX-UV) disinfection on C. difficile contamination of hospital room high-touch surfaces in Japan was evaluated., Methods: The environmental surfaces of 20 C. difficile infection (CDI) isolation rooms were sampled immediately after CDI patients were discharged or transferred. High-touch surfaces were sampled before and after either bleach cleaning or PX-UV disinfection in addition to nonbleach cleaning. Changes in the number of C. difficile-positive samples and bacterial counts for each cleaning method were assessed., Results: Overall, 286 samples were collected (bleach cleaning, 144 samples; PX-UV disinfection, 142 samples). Before cleaning, the positive rates of C. difficile were 27.8% and 31.0% in bleach cleaning and PX-UV disinfection, respectively. Both bleach cleaning and PX-UV disinfection significantly reduced overall C. difficile-positive samples (P = .018 and P = .002, respectively) and C. difficile colony-forming unit counts (P = .002 and P = .001, respectively)., Conclusions: PX-UV disinfection in addition to manual nonbleach cleaning effectively reduces C. difficile contamination from high-touch surfaces. Further studies are warranted to evaluate the effect of PX-UV disinfection on CDI rates in Japanese hospitals., (Copyright © 2020 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Background: The hospital environment is an important source of multidrug-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA). Here, we evaluated the efficacy of pulsed xenon ultraviolet (PX-UV) disinfection in addition to manual cleaning in a Japanese hospital., Methods: Environmental samples were collected from inpatient rooms that had been occupied for at least 48 hours by patients infected or colonized with MRSA. High-touch surfaces from 11 rooms were sampled before and after manual cleaning and then after PX-UV disinfection. Changes in bacterial counts and in the number of aerobic bacteria (AB)- and MRSA-positive samples between sampling points were assessed. The time taken to complete PX-UV treatment of patient rooms was also recorded., Results: A total of 306 samples were collected. PX-UV disinfection resulted in a significant decrease in abundance of AB and MRSA (mean colony-forming units 14.4 ± 38.7 to 1.7 ± 6.1, P < .001 and 1.1 ± 3.9 to 0.3 ± 2.0, P < .001, respectively) and in the number of AB- and MRSA-positive samples (58.8%-28.4%, P = .001 and 19.6%-3.9%, P < .001, respectively) compared with manual cleaning. The median time of in-room use of the PX-UV device was 20 minutes., Conclusions: The addition of PX-UV disinfection to the manual cleaning process significantly reduced AB and MRSA contamination of high-touch surfaces in hospital inpatient rooms., (Copyright © 2019 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)