Evaluation of in vitro efficiency of various antiviral agents on adenovirus

Evaluation of In Vitro Efficiency of Various Antiviral Agents on Adenovirus Purpose: To evaluate the efficiency of various antiviral agents that are likely to exhibit in vitro antiviral activity on an adenovirus isolate, that is the causative agent of conjunctivitis. Material and Methods: Conjunctival swab samples taken with flocked swab from patients who were diagnosed as adenoviral conjunctivitis were carried out on viral transport medium and sent to Virology Laboratory of Microbiology Department, Faculty of Medicine, Cukurova University. Clinical samples were inoculated into cell culture and adenovirus isolation was performed. Continuous cell line A549 cells were used for the isolation of adenovirus. The diagnosis of adenovirus was confirmed by Real-Time PCR test. An isolate of adenovirus that isolated in cell culture was propagated by serial passage. Adenovirus titration was detected by performing TCID50 assay protocol (Tissue Culture Infectious Dose 50 %). The same adenovirus isolate was used in all antiviral tests. The in vitro efficacy of Cidofovir, Cyclosporin-A (CSA), povidone iodine (PVP-I) and chlorhexidine (CHX) on adenovirus were investigated. For each drug, % 50 cytotoxic concentration (CC₅₀) to the cells was determined with MTS assay. Then, an antiviral efficacy test was performed in concentrations below CC₅₀, in this way the % 50 inhibitory concentrations (IC₅₀) of antiviral agents were found. Results: CC₅₀ values of agents in A549 cell culturewere found as 564 ± 26 µM in cidofovir, 6,11 ± 0,23 µM in CSA, 0,54 ± 0,06 % in PVP-I and 0,00058 ± 0,0002 % in CHX. While IC50 value of cidofovir against adenovirus was found as 3,07 ± 0,8 µM, CSA, PVP – I and CHX were not effective on adenovirus in concentrations below CC₅₀. Conclusion: It was determined that cidofovir have in vitro efficiency on adenovirus and the IC₅₀ value was detected in concentration ranges described in the literature. PVP-I and CHX were found to be highly cytotoxic even at low concentrations and it is considered as important to evaluate the efficacy/side effect profiles of these agents together in future clinical studies. In vitro efficiency of CSA on adenovirus was investigated first time in the literature. This agent was found as ineffective in sub- cytotoxic concentrations, but this study is thought to be a guide for future studies. KeyWords: Adenovirus, A549, antiviral activity, cell culture, in vitro