Evaluation of in vitro bactericidal activity of 1.5% olanexidine gluconate, a novel biguanide antiseptic agent

Recently, 1.5% olanexidine gluconate, a biguanide compounds, was launched as a new antiseptic agent in Japan. However, the comprehensive bactericidal spectrum of olanexidine gluconate is still unknown. In this study, we evaluated in vitro bactericidal activity of olanexidine gluconate using time-kill assay against various bacteria, mycobacteria, and fungi. With the exception of Burkholderia cepacia and Mycobacterium spp., 1.5% olanexidine gluconate exhibited fast-acting (≤60 s) bactericidal activity against all tested Gram-positive and Gram-negative bacteria, including vancomycin-resistant Enterococcus faecalis, methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, extended spectrum β-lactamase producing Klebsiella pneumoniae, and multidrug-resistant Pseudomonas aeruginosa. Furthermore, 1.5% olanexidine gluconate eradicated Candida albicans, Microsporum canis, and Malassezia furfur within 3 min. Our findings indicate that olanexidine gluconate has broad spectrum bactericidal activity; therefore, it may be useful for the prevention of a wide range of infectious diseases.