Abstract
Purpose: :
To examine the disinfectant efficacy of povidone-iodne, hydrogen peroxide, and multipurpose solutions against both planktonic and adherent bacteria in the contact lens storage cases
Methods: :
Six commercially available multipurpose solutions (MPSs), a commercially available hydrogen peroxide, and povidone-iodine were recruited in this study. Twelve clinical isolates (6 strains of Pseudomonas aeruginosa, 1strain of Pseudomonas fluorescens, 1strain of Stenotrophomonas maltophilia, 2 strains of Serratia marcescens, 1strain of Alcaligenes xylosoxidans, 1strain of Chryseobacterum indologenes) were cultivated in Y culture medium and controlled to 107 CFU/ml. The 4mL of disinfectants and 40µL of the controlled liquid were added in the cases. After the stationary cultivation for 4 hours, culture liquid was collected as planktonic bacteria. With regard to adherent bacteria, the 1mL of controlled Y medium was injected into the storage cases and cultivated stationary for 24 hours. The 4mL of disinfectants added into the cases after decantation of Y medium, and inside of the storage cases were scraped by Rasper Check (BD, Japan) after 4 hours. We collected bacteria from Rasper Check as adherent bacteria. Their log reductions of viable bacteria counts by disinfectants were determined in comparison to the loaded counts.
Results: :
The highest disinfection efficacy against planktonic bacteria of all the strains was found in povidone-iodine. Most MPSs showed > 3log reductions against all the strains. Although povidone-iodine and hydrogen peroxide showed > 4log reduction against adherent bacteria, MPSs showed < 3log reduction against them.
Conclusions: :
Povidone-iodine has an efficacy for disinfection of adherent bacteria to the contact lens storage cases as well as planktonic bacteria.