Inactivation of Feline Calicivirus and Adenovirus Type 40 by UV Radiation

Abstract

Little information regarding the effectiveness of UV radiation on the inactivation of caliciviruses and enteric adenoviruses is available. Analysis of human calicivirus resistance to disinfectants is hampered by the lack of animal or cell culture methods that can determine the viruses' infectivity. The inactivation kinetics of enteric adenovirus type 40 (AD40), coliphage MS-2, and feline calicivirus (FCV), closely related to the human caliciviruses based on nucleic acid organization and capsid architecture, were determined after exposure to low-pressure UV radiation in buffered demand-free (BDF) water at room temperature. In addition, UV disinfection experiments were also carried out in treated groundwater with FCV and AD40. AD40 was more resistant than either FCV or coliphage MS-2 in both BDF water and groundwater. The doses of UV required to achieve 99% inactivation of AD40, coliphage MS-2, and FCV in BDF water were 109, 55, and 16 mJ/cm 2 , respectively. The doses of UV required to achieve 99% inactivation of AD40, coliphage MS-2, and FCV in groundwater were slightly lower than those in BDF water. FCV was inactivated by 99% by 13 mJ/cm 2 in treated groundwater. A dose of 103 mJ/cm 2 was required for 99% inactivation of AD40 in treated groundwater. The results of this study indicate that if FCV is an adequate surrogate for human caliciviruses, then their inactivation by UV radiation is similar to those of other single-stranded RNA enteric viruses, such as poliovirus. In addition, AD40 appears to be more resistant to UV disinfection than previously reported.

Treatability of U.S. Environmental Protection Agency Contaminant Candidate List Viruses: Removal of Coxsackievirus and Echovirus using Enhanced Coagulation

“…The supernatant was collected and centrifuged at 4 °C at 1200g for 15 min to remove bacteria. To minimize DOC content, the stocks were purified using two successive polyethylene glycol (PEG) precipitations followed by a Vertrel XF (Micro Care Marketing Services, New Britain, CT) extraction and resuspension in BDF, as described by Thurston-Enriquez et al 17 Briefly, the suspension was augmented with 9% PEG (MW 8000) and 1 M NaCl and was allowed to stir overnight at 4 °C. It was then centrifuged at 4 °C at 8000g for 90 min.…”

Efficacy of Removal of CCL Viruses under Enhanced Coagulation Conditions

“…Cells were then subjected to freeze/thaw cycles: one for Ad4 and three for FCV-infected cells. 23 The supernatant was centrifuged at 4 °C at 8000g for 15 min to remove cellular debris. The virus suspension was purified and concentrated using poly(ethylene glycol) (PEG) precipitation, as described by Thurston-Enriquez et al 23 Briefly, the suspension was augmented with 9% PEG (MW 8000) and 1 M NaCl and was allowed to stir overnight at 4 °C.…”

Inactivation of Virus-Containing Aerosols by Ultraviolet Germicidal Irradiation

“…In 1942, the use of UVGI in schools greatly reduced the spread of measles, chickenpox, and mumps (Wells et al 1942). Recently, adenovirus was reported less susceptible to UVGI, possibly due to doublestranded DNA as its genetic material (Meng and Gerba 1996;Thurston-Enriquez et al 2003). Moreover, the required doses of UVGI for viruses were found to be lower than those for bacteria and fungi (Jensen 1964;Brickner et al 2003).…”

“…For deadly viruses such as Severe Acute Respiratory Syndrome (SARS) virus, influenza virus, and enterovirus, the vehicle transmission pathways include respiratory transmission by droplets and aerosols, as well as fecal-oral transmission via water, food, and environmental surfaces. To reduce infection risk from virus infection, control techniques for inactivating such viruses have been extensively researched (Jensen 1964;Gerba et al 2002;Shin et al 2003;Thurston-Enriquez et al 2003). Among these control techniques, ultraviolet germicidal irradiation (UVGI) was demonstrated to be extremely efficient for virus inactivation (Jensen 1964 ;Galasso et al 1965;Gerba et al 2002;Nuanualsuwan et al 2003;Thurston-Enriquez et al 2003).…”