In vitro comparing the antimicrobial activity of 2 % and 4 % of chlorhexidinegluconatein alcohol solution againstmethicillin-susceptible and methicillin-reisistant Staphylococcusaureus

Abstract

Chlorhexidine gluconate (CHG) has been well recognized in antimicrobial activity especially to Gram positive bacteria. However, there are several mixtures and concentrations of CHG used nowadays, thus, this may affect to its bactericidal and persistent activity. This study used four different CHG mixtures, including 2 % and 4 % CHG in 70 % ethyl alcohol (EtOH), and 2 % and 4 % CHG in 70 % isopropyl alcohol (IPA), to evaluate inhibitory titer and time-kill kinetic of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in an in vitro model. The results revealed that when tested at the same CHG concentration, inhibitory titers derived from both strains were very high and no comparable, indicating that MSSA and MRSA were still susceptible to CHG. Furthermore, all CHG mixtures could destroy MSSA and MRSA immediately within 15 seconds and also showed persistent activity for six hours of exposure in time-kill kinetic measurement. Although our study demonstrated that four different CHG mixtures had the similar properties of immediate and persistent antimicrobial activity to MSSA and MRSA, we recommend that using 2 % CHG is better than 4 % CHG in medical applications to avoid the problem of microorganisms drug resistance and skin irritation of patients. In addition, the optimal use of antiseptic can help to control and prevent the nosocomial infection problem effectively.