Ozone inactivation of cell-associated viruses

Abstract

The inactivation of HEp-2 cell-associated poliovirus (Sabin 1) and coxsackievirus A9 was investigated in three experimental systems, using ozone as a disinfectant. The cell-associated viral samples were adjusted to a turbidity of 5 nephelometric turbidity units. The cell-associated poliovirus and coxsackievirus samples demonstrated survival in a continuous-flow ozonation system at applied ozone dosages of 4.06 and 4.68 mg/liter, respectively, for 30 s. Unassociated viral controls were inactivated by the application of 0.081 mg of ozone per liter for 10 s. Ultrasonic treatment of cell-associated enteric viruses did not increase inactivation of the cell-associated viruses. The batch reactor with a declining ozone residual did not effect total inactivation of either cell-associated enteric virus. These cell-associated viruses were completely inactivated after exposure to ozone in a batch reactor using continuous ozonation. Inactivation of cell-associated poliovirus required a 2-min contact period with an applied ozone dosage of 6.82 mg/liter and a residual ozone concentration of 4.70 mg/liter, whereas the coxsackievirus was completely inactivated after a 5-min exposure to an applied ozone dosage of 4.81 mg/liter with an ozone residual of 2.18 mg/liter. These data indicate that viruses associated with cells or cell fragments are protected from inactivation by ozone concentrations that readily inactivate purified virus. The cell-associated viral samples used in this research contained particles that were 10 to 15 microns in size. Use of a filtration system before ozonation would remove these particles, thereby facilitating inactivation of any remaining viruses associated with cellular fragments.

Viral Inactivation in Foods: A Review of Traditional and Novel Food‐Processing Technologies

“…Ozone residuals of 4.70 and 5.45 mg/L were measured after a 2‐min treatment. In this study cell‐associated enteric viruses were protected from inactivation by exposure to ozone (Emerson and others 1982), which suggests that food matrices may also have a protective effect.…”

“…The presence of organic substances can neutralize the ozone needed to inactivate microoganisms when mixed with cells, cellular debris, food, or feces. Emerson and others (1982) studied the disinfection potential of ozone on human epithelial cells (HEp‐2) infected with poliovirus (Sabian type 1) and coxsackievirus A9 to simulate organic compounds of cells sloughed from the intestinal tract. Poliovirus unassociated with cells were completely inactivated at 0.28 mg/L of ozone in 10 s and coxsackievirus unassociated with cells were completely inactivated at 0.081 mg/L in 10 s. Alternatively, cell‐associated poliovirus was completely inactivated after a 2‐min contact time with much higher initial ozone concentrations of 6.82 and 6.50 mg/L.…”

PCNA‐expression of cementoblasts and fibroblasts on the root surface after extraoral rinsing for decontamination

“…Echerichia coli, Pseudomonas aeruginosa and Serratia marcescens , as well as Candida albicans (ozone concentration necessary for elimination 0.05–0.7 µg ml −1 ) are more susceptible than staphylococcae (3–5 µg ml −1 ) (22). Ozone concentrations over 5 µg ml −1 will eliminate all microorganisms (23) in a few seconds. The irrigation of avulsed teeth with ozonized water could, hence, not only decontaminate the root surface, but also may have a positive effect on the cementoblasts in the remaining PDL adhering to the root surface.…”

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“…Ozone inactivates many viruses directly. Norwalk, collophage MS3, hepatitis A, and poliovirus are dependent on reduced sulfhydryl groups [13][14][15][16][17][18]. "Reflecting on the reduction of "critical" disulfide bonds for vaccinia virus' cellular entry, Ryser found that protein disulfide isomerase inhibitors limited HIV-1 entry into T cells [19].…”