Disinfection efficacy and mechanism of olanexidine gluconate against norovirus

Tree Species-Dependent Inactivation of Coronaviruses and Enteroviruses on Solid Wood Surfaces

The ongoing challenge of viral transmission, exemplified by the Covid pandemic and recurrent viral outbreaks, necessitates the exploration of sustainable antiviral solutions. This study investigates the underexplored antiviral potential of wooden surfaces. We evaluated the antiviral efficacy of various wood types, including coniferous and deciduous trees, against enveloped coronaviruses and nonenveloped enteroviruses like coxsackie virus A9. Our findings revealed excellent antiviral activity manifesting already within 10 to 15 min in Scots pine and Norway spruce, particularly against enveloped viruses. In contrast, other hardwoods displayed varied efficacy, with oak showing effectiveness against the enterovirus. This antiviral activity was consistently observed across a spectrum of humidity levels (20 to 90 RH%), while the antiviral efficacy manifested itself more rapidly at 37 °C vs 21 °C. Key to our findings is the chemical composition of these woods. Resin acids and terpenes were prevalent in pine and spruce, correlating with their antiviral performance, while oak's high phenolic content mirrored its efficacy against enterovirus. The pine surface absorbed a higher fraction of the coronavirus in contrast to oak, whereas enteroviruses were not absorbed on those surfaces. Thermal treatment of wood or mixing wood with plastic, such as in wood-plastic composites, strongly compromised the antiviral functionality of wood materials. This study highlights the role of bioactive chemicals in the antiviral action of wood and opens new avenues for employing wood surfaces as a natural and sustainable barrier against viral transmissions.

Evaluation of the Inactivation Efficacy of Four Disinfectants for Feline Parvovirus Derived from Giant Panda

Feline panleukopenia (FPL) is a highly contagious acute infectious disease caused by feline parvovirus (FPV). FPV has also been found in giant pandas with clinical signs of vomiting and mild diarrhea, posing a threat to this vulnerable species. Cleaning and disinfection may be one of the most efficacious ways to prevent FPV spread in the habitat of giant pandas. This study evaluated the inactivation effect of peracetic acid (PAA), povidone-iodine (PVP-I), glutaral and deciquam solution (JM) and Virkon S. The tissue culture infective dose (TCID₅₀) assay indicated that the virus may be totally inactivated by JM, PAA and Virkon S. Meanwhile, the hemagglutination (HA) assay showed a high inactivation efficiency of PAA and Virkon S. The analysis of Western blot revealed that PAA, Virkon S and JM can inhibit the structural protein synthesis. Taken together, our findings demonstrated that PAA could rapidly and efficiently inactivate FPV, representing an efficacious disinfectant for FPV control.

Combination of Cetylpyridinium Chloride and Chlorhexidine Acetate: A Promising Candidate for Rapid Killing of Gram-Positive/Gram-Negative Bacteria and Fungi

Combined use of the present antimicrobial drugs has been proved to be an alternative approach for antimicrobial agents' development since the co-existed of the drugs working in different mechanism have been demonstrated potentially enhance their antimicrobial activity. In this work, antibacterial and antifungal activity of the cetylpyridinium chloride (CPC)/chlorhexidine acetate (CHA) combination was evaluated for the first time, while a universal concentration for the rapid killing of gram-positive/gram-negative bacteria and fungi was also proposed. The minimum inhibitory concentrations (MIC) of CPC and CHA used alone or in combination were first measured, showing that the combined treatment decreased the MIC against tested gram-positive/gram-negative bacteria and fungi to 1/8-1/2. Growth curve assays demonstrated CPC and CHA had dynamic combined effects against the tested microorganisms at the concentration equal to MIC. Besides, combined use of these two drugs could also enhance their biocidal activity, which was illustrated by fluorescence microscopy and SEM images, as well as soluble protein measurement. More importantly, in vitro acute eye and skin irritation tests showed short-term contact with CPC/CHA combination would not cause any damage to mammalian mucosa and skin. In a word, CPC/CHA combination exhibited broad-spectrum antibacterial and antifungal activity against tested gram-positive/gram-negative bacteria and fungi while without any acute irritation to mammalian mucosa and skin, providing a new perspective on the selection of personal disinfectants.

Antiviral Activity of Olanexidine-Containing Hand Rub against Human Noroviruses

Human norovirus (HuNoV) is the leading cause of epidemic and sporadic acute gastroenteritis worldwide. HuNoV transmission occurs predominantly by direct person-to-person contact, and its health burden is associated with poor hand hygiene and a lack of effective antiseptics and disinfectants. Specific therapies and methods to prevent and control HuNoV spread previously were difficult to evaluate because of the lack of a cell culture system to propagate infectious virus. This barrier has been overcome with the successful cultivation of HuNoV in nontransformed human intestinal enteroids (HIEs). Here, we report using the HIE cultivation system to evaluate the virucidal efficacy of an olanexidine gluconate-based hand rub (OLG-HR) and 70% ethanol (EtOH_70%) against HuNoVs. OLG-HR exhibited fast-acting virucidal activity against a spectrum of HuNoVs including GII.4 Sydney[P31], GII.4 Den Haag[P4], GII.4 New Orleans[P4], GII.3[P21], GII.17[P13], and GI.1[P1] strains. Exposure of HuNoV to OLG-HR for 30 to 60 s resulted in complete loss of the ability of virus to bind to the cells and reduced in vitro binding to glycans in porcine gastric mucin. By contrast, the virucidal efficiency of EtOH_70% on virus infectivity was strain specific. Dynamic light scattering (DLS) and electron microscopy of virus-like particles (VLPs) show that OLG-HR treatment causes partial disassembly and possibly conformational changes in VP1, interfering with histo-blood group antigen (HBGA) binding and infectivity, whereas EtOH_70% treatment causes particle disassembly and clumping of the disassembled products, leading to loss of infectivity while retaining HBGA binding. The highly effective inactivation of HuNoV infectivity by OLG-HR suggests that this compound could reduce HuNoV transmission.