Virus disinfection for biotechnology applications: Different effectiveness on surface versus in suspension

Efficacy of Disinfectants for Monkeypox Virus Inactivation on High Touch Surface Materials in Low-Resource Settings

Disinfection efficacy tests were conducted on surface carriers inoculated with the monkeypox virus (MPXV) by applying six disinfectant solutions (and three controls) on six surfaces common in low-resource settings: four nonporous surfaces (stainless steel, glass, plastic, and latex) and two porous surfaces (ceramic and wood). Disinfectants were wiped on carriers in triplicate, with a 1 min contact time: 0.05 and 0.5% sodium hypochlorite, 70% ethanol, two quaternary ammonium compound (QAC)-based disinfectants, and 1.4% hydrogen peroxide. MPXV was then quantified, and log10 removal values were calculated. Sodium hypochlorite (0.05 and 0.5%) and ethanol (70%) removed MPXV to below detection level, ≥ 99.97% reduction for nonporous surfaces, and ≥99.40% for wood, QAC-based disinfectants were efficacious on nonporous surfaces (≥99.97% inactivation) but had diminished efficacy on wood, a porous surface, and 1.4% H2O2 had limited efficacy across all tested surfaces. Results varied by disinfectant type and surface type. Based on our results, we recommend using 0.05% sodium hypochlorite or 70% ethanol with 1 min contact time to inactive MPXV on clean nonporous and porous surfaces. As MPXV is evolving, future research with additional disinfectants, application methods, and environmental conditions and research to understand adsorption, disinfection efficacy, and transmission risk on porous surfaces are needed to develop practical disinfection recommendations.

In Vitro Virucidal Activity of Different Essential Oils against Bovine Viral Diarrhea Virus Used as Surrogate of Human Hepatitis C Virus

The hepatitis C virus (HCV) is a major hepatotropic virus that affects humans with increased risk of developing hepatocellular carcinoma. The bovine viral diarrhea virus (BVDV) causes abortion, calf mortality and poor reproductive performance in cattle. Due the difficulties of in vitro cultivation for HCV, BVDV has been used as surrogate for in vitro assessment of the efficacy of antivirals. Essential oils (EOs) display antiviral and virucidal activity on several viral pathogens. In this study, the virucidal activity of five EOs, Salvia officinalis L. EO (SEO), Melissa officinalis L. EO (MEO), Citrus lemon EO (LEO), Rosmarinus officinalis L. EO (REO) and Thymus vulgaris L. EO (TEO) against BVDV was evaluated in vitro at different concentrations for several time contacts. MEO and LEO were able to considerably inactivate BVDV with a time- and dose-dependent fashion. MEO and LEO at the highest concentrations decreased viral titer by 2.00 and 2.25 log10 TCID50/50 μL at 8 h contact time, respectively. SEO, REO and TEO displayed mild virucidal activity at the highest concentrations for 8 h contact times. In this study, the virucidal efficacies of MEO and LEO against BVDV were observed regardless of compound concentration and contact time. Further studies are needed to confirm the potential use of MEO and LEO as surface disinfectants.

A review on sterilization methods of environmental decontamination to prevent the coronavirus SARS-CoV-2 (COVID-19 virus): A new challenge towards eco-friendly solutions

In recent years, the COVID-19 pandemic is currently wreaking havoc on the planet. SARS-CoV-2, the Severe Acute Respiratory Syndrome Coronavirus, is the current term for this outbreak. Reports about this novel coronavirus have been presented since the pandemic's breakout, and they have demonstrated that it transmits rapidly from person to person, primarily by droplets in the air. Findings have illustrated that SARS-CoV-2 can survive on surfaces from hours to days. Therefore, it is essential to find practical solutions to reduce the virus's impact on human health and the environment. This work evaluated common sterilization methods that can decontaminate the environment and items. The goal is that healthcare facilities, disease prevention organizations, and local communities can overcome the new challenge of finding eco-friendly solutions. Further, a foundation of information encompassing various sterilization procedures and highlighting their limits to choose the most appropriate method to stop disease-causing viruses in the new context has been presented. The findings of this crucial investigation contribute to gaining insight into the comprehensive sterilization approaches against the coronavirus for human health protection and sustainable environmental development.

Surface Inactivation of a SARS-CoV-2 Surrogate with Hypochlorous Acid is Impacted by Surface Type, Contact Time, Inoculum Matrix, and Concentration

Indirect contact with contaminated surfaces is a potential transmission route for COVID-19. Therefore, it is necessary to investigate convenient and inexpensive surface sanitization methods, such as HOCl, against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 surrogate, Phi6 (~ 7 log PFU/mL), was prepared in artificial saliva and tripartite matrices, spot inoculated on coupons of either stainless steel or vinyl, and allowed to dry. The coupons were sprayed with either 500 ppm or 1000 ppm HOCl, and remained on the surface for 0 s (control), 5 s, 30 s, or 60 s. Samples were enumerated via the double agar overlay assay. Statistical analysis was completed in R using a generalized linear model with Quasipoisson error approximations. Time, concentration, surface type, and inoculum matrix were all significant contributors to log reduction at P = 0.05. Significant three-way interactions were observed for 1000 ppm, vinyl, and 60 s (P = 0.03) and 1000 ppm, tripartite, and 60 s (P = 0.0121). A significant two-way interaction between vinyl and 60 s was also observed (P = 0.0168). Overall, increased HOCl concentration and exposure time led to increased Phi6 reduction. Notably, the highest estimated mean log reduction was 3.31 (95% CI 3.14, 3.49) for stainless steel at 60 s and 1000 ppm HOCl in artificial saliva, indicating that this method of sanitization may not adequately reduce enveloped viruses to below infective thresholds.

Redspotted Grouper Nervous Necrosis Virus and the Reassortant RGNNV/SJNNV In Vitro Susceptibility against a Commercial Peroxy-Acid Biocide under Different Conditions of Use

Aquaculture is a constantly growing sector. The intensification of fish production and the movement of aquatic animals could cause the spread of infectious diseases. Remarkably, the diffusion of viral agents represents the major bottleneck for finfish production, and viral encephalopathy and retinopathy (VER) is considered the most impacting disease for Mediterranean aquaculture. No effective therapies are available to contrast VER, and vaccination can be applied only in grow-out facilities. Hence, programs to minimize the sanitary risks in farms are paramount to implementing hygienic standards and biosecurity. This study aimed to evaluate the in vitro virucidal activity of a peroxy-acid disinfectant (Virkon^® S, DuPont, Sudbury, UK) towards the two NNV strains most widespread in the Mediterranean Sea. Remarkably, two protocols were applied to assess the virucidal activity under different conditions of use: the suspension test and the net test. The latter has been applied to evaluate the efficacy of the biocide on instruments, simulating the in-field application. The obtained results demonstrated the suitability of the tested biocide for NNV inactivation, being effective under some of the tested conditions. However, the presence of organic matter, the concentration of the product, and the application conditions can significantly affect the result of the disinfection procedure.

Efficacy of hydrogen peroxide wipes for decontamination of AZD1222 adenovirus COVID-19 vaccine strain on pharmaceutical industry materials

This study aimed to evaluate the performance of accelerated hydrogen peroxide® wipes (HPW) for decontamination of the chimpanzee adenovirus AZD1222 vaccine strain used in the production of recombinant COVID‐19 vaccine in a pharmaceutical industry. Two matrices were tested on stainless‐steel (SS) and low‐density‐polyethylene (LDP) surfaces: formulated recombinant COVID‐19 vaccine (FCV) and active pharmaceutical ingredient (API). The samples were spiked, dried and the initial inoculum, possible residue effect (RE) and titre reduction after disinfection with HPW were determined. No RE was observed. The disinfection procedure with HPW resulted in complete decontamination the of AZD1222 adenovirus strain in FCV (≥7·46 and ≥7·49 log₁₀ infectious unit [IFU] ml⁻¹ for SS and LDP carriers respectively) and API (≥8·79 and ≥8·78 log₁₀ IFU ml⁻¹ for SS and LDP carriers respectively). In conclusion, virucidal activity of HPW was satisfactory against the AZD1222 adenovirus strain and can be a good option for disinfection processes of SS and LPD surfaces in pharmaceutical industry facilities during recombinant COVID‐19 vaccine production. This procedure is simple and can be also applied on safety unit cabins and sampling bags made of LDP as well.

Evaluation of hydrogen peroxide efficacy against AZD1222 chimpanzee adenovirus strain in the recombinant COVID-19 vaccine for application in cleaning validation in a pharmaceutical manufacturing industry

This study aimed to evaluate the performance of hydrogen peroxide vapour (HPV) to inactivate the chimpanzee adenovirus AZD1222 vaccine strain used in the production of recombinant COVID-19 vaccine for application in cleaning validation in pharmaceutical industries production areas. Two matrixes were tested: formulated recombinant COVID-19 vaccine (FCV) and active pharmaceutical ingredient (API). The samples were dried on stainless steel and exposed to HPV in an isolator. One biological indicator with population >10⁶ Geobacillus stearothermophilus spores was used to validate the HPV decontamination cycle as standard. HPV exposure resulted in complete virus inactivation in FVC (≥5·03 log₁₀ ) and API (≥6·40 log₁₀ ), showing HPV efficacy for reducing chimpanzee adenovirus AZD1222 vaccine strain. However, the optimum concentration and contact time will vary depending on the type of application. Future decontamination studies scaling up the process to the recombinant COVID-19 vaccine manufacturing areas are necessary to evaluate if the HPV will have the same or better virucidal effectivity in each specific production area. In conclusion, HPV showed efficacy for reducing AZD1222 chimpanzee adenovirus strain and can be a good choice for pharmaceutical industries facilities disinfection during recombinant COVID-19 vaccine production.

Inactivation of SARS-CoV-2 in the Liquid Phase: Are Aqueous Hydrogen Peroxide and Sodium Percarbonate Efficient Decontamination Agents?

A diluted 3% w/w hydrogen peroxide solution acidified to pH 2.5 by adding citric acid inactivated SARS-CoV-2 virus by more than 4 orders of magnitude in 5 min. After a contact time of 15 min, no viral replication was detected. Aqueous solutions of sodium percarbonate inactivated coronavirus by >3 log10 diminution in 15 min. Conversely, H2O2 solutions with no additives displayed a scarce virucidal activity (1.1 log10 diminution in 5 min), confirming that a pH-modifying ingredient is necessary to have a H2O2-based disinfectant active against the novel coronavirus.

Evaluation of hydrogen peroxide virucidal efficacy against yellow fever virus 17DD vaccine strain for application in a vaccine manufacturing industry

The aim of this study was to evaluate the inactivation performance of hydrogen peroxide to the yellow fever virus 17DD vaccine strain, used for the production of attenuated yellow fever vaccine, in two matrixes: formulated yellow fever vaccine (FYV) and yellow fever viral suspension - active pharmaceutical ingredient (API). The samples were dried on stainless steel and exposed to hydrogen peroxide liquid (HPL) at concentrations of 30, 10, 3 and 1% for 20 and 60 min; and to hydrogen peroxide vapour (HPV) in an isolator. The exposure to HPL 30 and 10 %, within 20 min, reduced the virus titre at least 3.85 log₁₀ PFU/mL (74.8 %). During 60 min of exposure, the HPL 30, 10 and 3% reduced the virus titre by at least 3.18 log₁₀ PFU/mL (62.6 %). HPV exposure resulted in complete virus inactivation in FYV (≥ 4.42 log₁₀ PFU/mL reduction) and for API samples 3.17 log₁₀ PFU/mL (64.3 %) reduction. Hydrogen peroxide showed to be a promising disinfectant for elimination of yellow fever virus. However, the optimum concentration and contact time will vary depending on the type of application, and as such may complement individual risk assessments of biological production processes.

Etiological factors in triggering non-specific allergic reactions to tuberculin in cattle

The article presents the results of allergic and bacteriological studies of cattle from a tuberculosis-free farm. The presence of cattle reacting to an allergen from atypical mycobacteria was established in three allergic simultaneous tests during 2019–2020. Based on the results obtained, the causative agent of tuberculosis and atypical mycobacteria were not isolated during the bacteriological examination of a biological material from animals slaughtered for diagnostic purposes (n = 17), as well as soil (n = 5) and straw (n = 3) samples. However, microorganisms of the genera Nocardia (n = 2), Rhodococcus (n = 10), and Actinomyces (n = 5) were isolated from the biomaterial according to the results of microscopy, culture and biochemical tests. These microorganisms were also isolated from the soil and straw samples. Short-term non-specific reactions in cattle to mycobacterial allergens were due to the persistence and circulation of the aforementioned microorganisms closely related to mycobacteria. It was determined that the genera Nocardia and Rhodococcus are sensitive to the 1.0%, 2.0%, 3.0% solutions of glutaraldehyde, formaldehyde and sodium hydroxide. Thus, it is necessary to take into account the epizootic situation as to the presence of nocardioform microorganisms in the herd during routine allergic studies, as well as in case of differentiation between specific reactions and paraallergic and pseudoallergic ones. It is necessary to carry out comprehensive systematic studies of livestock and feed quality assessment. For the purpose of disinfection, glutaraldehyde and formaldehyde at a concentration of 1.0% are effective in destroying microorganisms of the genera Nocardia and Rhodococcus with 3-hour exposure or more.

A Critical Review of Disinfection Processes to Control SARS-CoV-2 Transmission in the Food Industry

Industries of the food sector have made a great effort to control SARS-CoV-2 indirect transmission, through objects or surfaces, by updating cleaning and disinfection protocols previously focused on inactivating other pathogens, as well as food spoilage microorganisms. The information, although scarce at the beginning of the COVID-19 pandemic, has started to be sufficiently reliable to avoid over-conservative disinfection procedures. This work reviews the literature to propose a holistic view of the disinfection process where the decision variables, such as type and concentration of active substances, are optimised to guarantee the inactivation of SARS-CoV-2 and other usual pathogens and spoilage microorganisms while minimising possible side-effects on the environment and animal and human health.

Disinfection of N95 masks artificially contaminated with SARS-CoV-2 and ESKAPE bacteria using hydrogen peroxide plasma: Impact on the reutilization of disposable devices

INTRODUCTION

One of the serious consequences of the SARS-CoV-2 pandemic is the shortage of protective equipment for health personnel. N95 masks are considered one of the essential protective equipment in the management of patients with COVID-19. The shortage of N95 masks implies potential health risks for health personnel and significant economic losses for the health institution. The objective of this work was to investigate the disinfection of N95 masks artificially contaminated with SARS-CoV-2 and ESKAPE bacteria by using hydrogen peroxide plasma.

MATERIAL AND METHODS

We examined the disinfection capacity of hydrogen peroxide plasma against the SARS-CoV-2 and 2 members of the ESKAPE bacteria (Acinetobacter baumannii and Staphylococcus aureus) through a study of artificial contamination in situ of N95 masks. Amplification of specific genes by real-time reverse transcription polymerase chain reaction of SARS-CoV-2 and microbiological culture of ESKAPE bacteria was performed before and after the disinfection process.

RESULTS

SARS-CoV-2 was not detected in all assays using 5 different concentrations of the virus, and A baumannii and S aureus were not cultivable with inoculums of 102 to 106 CFU after disinfection tests of N95 masks with hydrogen peroxide plasma.

CONCLUSION

Disinfection of N95 masks by using the hydrogen peroxide plasma technology can be an alternative for their reuse in a shortage situation. Implications for the use of disinfection technologies of N95 masks and the safety of health personnel are discussed.