Inactivation of human adenovirus genome by different groups of disinfectants

Human adenoviruses are model viruses for testing the virucidal efficacy of disinfectants. However, a recent study has shown that the chemical sensitivity of adenovirus serotypes varies significantly, possibly due to the composition of the viral capsid and/or the resistance of nucleic acids. We have investigated the effect of molecular changes in the viral genome of the human adenovirus subgenera C and D. A common oligonucleotide fragment within the hexon gene was amplified by polymerase chain reaction (PCR) after exposure to liposomal povidone-iodine (PVP-I), peracetic acid (PAA), and formaldehyde. The findings were compared with infectivity in cell cultures. PVP-I (0.125%) destroyed the infectivity of most serotypes within 60 min. However, PCR revealed no destruction of the adenoviral genome in most serotypes, even after exposure to higher PVP-I concentrations. PAA (0.5%) failed to inactivate the hexon gene of adenovirus types 22 and 44. Furthermore, the hexon gene of adenovirus type 22 was not altered by 0.7% formaldehyde. In conclusion, the genomes of human adenoviruses show considerably more chemical resistance than the complete viral particle. The molecular resistance of individual serotypes also varies. However, there was no clear correlation between the differences in the effect of disinfectants on infectivity of the complete viral particle and destruction of the viral genome.