Genetic, Structural, and Phenotypic Properties of MS2 Coliphage with Resistance to ClO₂Disinfection

Abstract

Common water disinfectants like chlorine have been reported to select for resistant viruses, yet little attention has been devoted to characterizing disinfection resistance. Here, we investigated the resistance of MS2 coliphage to inactivation by chlorine dioxide (ClO). ClO inactivates MS2 by degrading its structural proteins, thereby disrupting the ability of MS2 to attach to and infect its host. ClO-resistant virus populations emerged not only after repeated cycles of ClO disinfection followed by regrowth but also after dilution-regrowth cycles in the absence of ClO. The resistant populations exhibited several fixed mutations which caused the substitution of ClO-labile by ClO-stable amino acids. On a phenotypic level, these mutations resulted in a more stable host binding during inactivation compared to the wild-type, thus resulting in a greater ability to maintain infectivity. This conclusion was supported by cryo-electron microscopy reconstruction of the virus particle, which demonstrated that most structural modification occurred in the putative A protein, an important binding factor. Resistance was specific to the inactivation mechanism of ClO and did not result in significant cross-resistance to genome-damaging disinfectants. Overall, our data indicate that resistant viruses may emerge even in the absence of ClO pressure but that they can be inactivated by other common disinfectants.

Photodynamic inactivation of non-enveloped RNA viruses

“…RNA viruses rapidly evolve and therefore viruses with resistance to antiviral agents and disinfectants can arise when viruses are repeatedly exposed to sub-lethal doses of these agents (Carratalà et al, 2017, Bates et al, 1977a, Feigelstock et al, 2011, Foll et al, 2014, Hué et al, 2009, Irwin et al, 2016, Zhong et al, 2016, Zhong et al, 2017. PDI is an efficient antiviral agent for viral control, with only one study reporting an attempt to select PDI-resistant viruses (Costa et al, 2011).…”

“…I238V, and R9M) as well as the lysis protein have been previously reported as conferring resistance against ClO2 following repeated exposure to this disinfectant (Zhong et al, 2016). Since the MS2 lysis protein is essential to viral egress through the induction of host-cell lysis (Walderich et al, 1988), the emergence of the lysis protein mutation (Q7P) (Zhong et al, 2016) among TMPyP-PDI selected viruses suggests that sub-lethal doses of TMPyP in solution could target other stages of the viral life cycle. However, as no resistant viruses were selected, it is also possible that the mutations did not arise as a result of TMPyP treatment.…”

“…Studies have reported on the emergence of resistant viruses upon continuous administration of antiviral drugs and exposure to common water disinfectants e.g. resistance of HIV to antiretroviral drugs (Hué et al, 2009), influenza virus to oseltamivir (Foll et al, 2014), hepatitis C virus to ribavirin (Feigelstock et al, 2011), bacteriophage MS2 and human echovirus 11 to chlorine dioxide (ClO2) (Zhong et al, 2016, Zhong et al, 2017, poliovirus and bacteriophage F116 to free chlorine (Bates et al, 1977b, Payment et al, 1985 and human echovirus 11 to Ultraviolet C (UVC) (Carratalà et al, 2017).…”

Structures of enveloped virions determined by cryogenic electron microscopy and tomography

“…As many enveloped viruses are human and animal pathogens, their production, purification and preparation for cryo-EM requires suitable containment facilities and bio-safety protocols (Sherman et al, 2013). To circumvent the need for decontaminating cryo-EM equipment, which may be in some cases impractical, purified virions can be inactivated for example by chemical fixation (Bharat et al, 2011;Halldorsson et al, 2018;Li et al, 2016b) or ultraviolet radiation (Park et al, 2011;Ye et al, 2018;Zhong et al, 2016) prior to cryo-EM sample preparation. Alternatively, virus-like particles (VLPs) that contain the relevant viral structural proteins with a lipid bilayer can be used as a model system instead of the native virion Sun et al, 2013).…”

Preparation and electrochemical performance of uniform RuO2/Ti and RuO2‐IrO2/Ti electrode for electrolysis of NaCl solution

“…Chemical agents, such as ozone and other chemical materials, inactivate a special enzyme of the microorganism, or degrade the cytoplasm of the bacteria through an oxidation reaction. Recently, Cl 2 , NH 4 Cl, ClO 2 , O 3 , and NaClO have been commonly used as disinfecting agents. NaClO has acceptable solubility in water, can be dissolved with water in any ratio, and have no disinfection by‐products that are toxic or harmful to human health.…”