Evaluation of antiseptic disinfectant activity with static light scattering technology

Background and aims. Healthcare-associated infections (HAI) are an increasingly important issue, for this reason disinfection and antisepsis practices acquire importance. The use of products with antiseptic activity and reports of resistance to these molecules, pose the need to test, in the local area, the sensitivity pattern. The aim of this study is to verify the ability of the analytical system Alfred 60AST (Alifax Spa Isola dell’Abbà, Polverara - PD - Italy) in evaluating the antimicrobial effectiveness in vitro of different molecules in comparison to the membrane filtration reference method, in accordance with the procedure NF T72- 152 proposed by the Association Française de Normalisation (AFNOR).
Materials and Methods. We used four antiseptic-disinfectant substances, commonly used in hospital practic: Iodopovidone, Ethanol, Chlorhexidine and DECS. ATCC strains were assessed both with clinical isolates. The eventual development occurs by means of microbial ALFRED AST60 was carried out in progressive times (30, 60 and 120 minutes) with different dilutions for each of the disinfectant molecules tested.
Results and Conclusions. Comparison tests carried out between membrane filtration method and instrumentation Alfred 60AST gave results almost totally concordant. The analyzer Alfred 60AST can then be appropriately adapted to the in vitro evaluation of antiseptics, representing a valuable aid in the periodic monitoring of their activities and the prior assessment of sensitivity for therapeutic use. Though preliminary, the study confirms the existence of bacteria resistant to alcohols and biguanides, and it emphasizes the opportunity to verify the in vitro sensitivity profile.