Cellulosic copper nanoparticles and a hydrogen peroxide-based disinfectant trigger rapid inactivation of pseudoviral particles expressing the Spike protein of SARS-CoV-2, SARS-CoV, and MERS-CoV

Mechanisms of action of microbicides commonly used in infection prevention and control

SUMMARYUnderstanding how commonly used chemical microbicides affect pathogenic microorganisms is important for formulation of microbicides. This review focuses on the mechanism(s) of action of chemical microbicides commonly used in infection prevention and control. Contrary to the typical site-specific mode of action of antibiotics, microbicides often act via multiple targets, causing rapid and irreversible damage to microbes. In the case of viruses, the envelope or protein capsid is usually the primary structural target, resulting in loss of envelope integrity or denaturation of proteins in the capsid, causing loss of the receptor-binding domain for host cell receptors, and/or breakdown of other viral proteins or nucleic acids. However, for certain virucidal microbicides, the nucleic acid may be a significant site of action. The region of primary damage to the protein or nucleic acid is site-specific and may vary with the virus type. Due to their greater complexity and metabolism, bacteria and fungi offer more targets. The rapid and irreversible damage to microbes may result from solubilization of lipid components and denaturation of enzymes involved in the transport of nutrients. Formulation of microbicidal actives that attack multiple sites on microbes, or control of the pH, addition of preservatives or potentiators, and so on, can increase the spectrum of action against pathogens and reduce both the concentrations and times needed to achieve microbicidal activity against the target pathogens.

Treatment of severe COVID-19: an evolving paradigm

INTRODUCTION

The pathogenesis of severe COVID-19 is due, in part, to dysregulation of the human immune system in response to SARS-CoV-2 infection. Immune cells infected with SARS-CoV-2 can trigger a hyperinflammatory response of both the adaptive and innate immune system that has been associated with severe disease, hospitalization, and death, and better treatment options are urgently needed.

AREAS COVERED

A mainstay of therapy for COVID-19 involves an antiviral agent, remdesivir, in combination with a systemic corticosteroid, dexamethasone.

EXPERT OPINION

The addition of a second immunomodulator, such as an interleukin-6 inhibitor or a Janus kinase inhibitor, has been associated with clinical benefit in a subset of patients with moderate-to-severe disease, but their use remains controversial. This manuscript reviews what is known about the approach to treatment of severe COVID-19 and examines how immunomodulators such as infliximab and abatacept may alter clinical management and COVID-19 research in the years ahead based on the results of randomized, controlled trials.