Addressing personal protective equipment (PPE) decontamination: Methylene blue and light inactivates severe acute respiratory coronavirus virus 2 (SARS-CoV-2) on N95 respirators and medical masks with maintenance of integrity and fit.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has resulted in shortages of personal protective equipment (PPE), underscoring the urgent need for simple, efficient, and inexpensive methods to decontaminate masks and respirators exposed to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). We hypothesized that methylene blue (MB) photochemical treatment, which has various clinical applications, could decontaminate PPE contaminated with coronavirus. DESIGN: The 2 arms of the study included (1) PPE inoculation with coronaviruses followed by MB with light (MBL) decontamination treatment and (2) PPE treatment with MBL for 5 cycles of decontamination to determine maintenance of PPE performance. METHODS: MBL treatment was used to inactivate coronaviruses on 3 N95 filtering facepiece respirator (FFR) and 2 medical mask models. We inoculated FFR and medical mask materials with 3 coronaviruses, including SARS-CoV-2, and we treated them with 10 µM MB and exposed them to 50,000 lux of white light or 12,500 lux of red light for 30 minutes. In parallel, integrity was assessed after 5 cycles of decontamination using multiple US and international test methods, and the process was compared with the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O3) decontamination method. RESULTS: Overall, MBL robustly and consistently inactivated all 3 coronaviruses with 99.8% to >99.9% virus inactivation across all FFRs and medical masks tested. FFR and medical mask integrity was maintained after 5 cycles of MBL treatment, whereas 1 FFR model failed after 5 cycles of VHP+O3. CONCLUSIONS: MBL treatment decontaminated respirators and masks by inactivating 3 tested coronaviruses without compromising integrity through 5 cycles of decontamination. MBL decontamination is effective, is low cost, and does not require specialized equipment, making it applicable in low- to high-resource settings.

Elevating the standard of endoscope processing: Terminal sterilization of duodenoscopes using a hydrogen peroxide-ozone sterilizer.

BACKGROUND: The health care community is increasingly aware of the processing challenges and infection risks associated with duodenoscopes owing to published reports of outbreaks and regulatory recalls. Studies have demonstrated that the current practices are inadequate for consistently producing patient-ready endoscopes. Alternatively, terminal sterilization would offer a greater margin of safety and potentially reduce the risk of patient infection. The purpose of this study was to evaluate the efficacy of a hydrogen peroxide-ozone sterilizer with regulatory clearance for terminal sterilization of duodenoscopes. METHODS AND RESULTS: Validation studies were performed under laboratory simulated-use and clinical in-use conditions. The overkill method study demonstrated a reduction of at least 6-log of Geobacillus stearothermophilus spores at half-cycle, providing a sterility assurance level of 10-6. In addition, the sterilizer achieved a 6-log reduction of G stearothermophilus in the presence of inorganic and organic soils in a simulated-use study. The clinical in-use study confirmed that the sterilizer achieved sterilization of patient-soiled duodenoscopes under actual use conditions. CONCLUSIONS: Simulated-use and clinical in-use studies demonstrated the efficacy of a hydrogen peroxide-ozone sterilizer for terminal sterilization of duodenoscopes. This offers health care facilities a viable alternative for duodenoscope processing to enhance patient safety as part of a comprehensive infection control strategy.

Altered expression of the poly(ADP-ribosyl)ation enzymes in uveal melanoma and regulation of PARG gene expression by the transcription factor ERM.

PURPOSE: Poly(ADP-ribosyl)ation is a reversible post-translational modification that requires the contribution of the enzymes poly(ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose) glycohydrolase (PARG). Our study explores expression and activity of PARP-1 and PARG in uveal melanoma cell lines with varying tumorigenic properties. METHODS: Gene profiling on microarrays was conducted using RNA prepared from the uveal melanoma cell lines T97, T98, T108, and T115. The activity of PARP-1 and PARG was monitored by enzymatic assays, whereas their expression was measured by Western blot and PCR. The PARG promoter was analyzed using promoter deletions and site-specific mutagenesis in transfection analyses. The transcription factors binding the PARG promoter were studied by electrophoretic mobility shift assay (EMSA) analyses. Suppression of PARP-1 and PARG expression was performed in T97 and T115 cells by RNAi, and their tumorigenic properties monitored by injections into athymic mice. RESULTS: Expression of PARP-1 was found to vary considerably between uveal melanoma cell lines with distinctive tumorigenic properties in vivo. Sp1 and the ETS protein ERM were shown to bind to the PARG gene promoter to ensure basal transcription in uveal melanoma. Importantly, suppression of PARG gene expression in T97 and T115 cells increased their capacity to form tumors in athymic mice, whereas suppression of PARP-1 significantly reduced or almost entirely abolished tumor formation. CONCLUSIONS: Our results suggest that while overexpression of PARP-1 may confer a proliferative advantage to aggressive uveal melanoma tumors, PARG may, on the other hand, support a tumor suppressor function in vivo.