HAND DISINFECTANTS AND THEIR ACTIVITY AGAINST CLINICAL ISOLATES OF BORDETELLA PERTUSSIS

Objectives: The aim of the study was to investigate possible emergence of resistance to disinfectants in Bordetella pertussis strains isolated from patients with whooping cough in the Czech Republic in 2014 and 2015. Methods: In an EN1500-based study, clean and dry fingertips of volunteers were always contaminated with one of the two clinical isolates of B. pertussis. Clinical isolates of B. pertussis were obtained from the National Reference Laboratory for Pertussis and Diphtheria, National Institute of Public Health (NIPH), Prague, Czech Republic. Dry and contaminated fingertips were immersed in 10 ml medium and then rubbed with the fingers for 1 minute. After that, the hands were treated with isopropanol 60% v/v or tested products, and then the fingertips were rubbed again into 10 ml of pure medium for 1 minute. The suspensions obtained were immediately diluted and plated on charcoal medium. Results: Ethanol-based product A and propanol-based product B showed bactericidal activity after 30 s of contact. The confidence interval limit for product A and B was 0.12 and 0.19, respectively. Quaternary ammonium compound-based product C was found to be ineffective after 30 s of contact. The confidence interval limit for product C was 0.62. Conclusion: Products A and B were assessed as effective against clinical isolates of B. pertussis in accordance with EN 1500. Quaternary ammonium compound-based product C did not comply with the requirements of EN 1500.