Efficacy of hand disinfectants against vancomycin-resistant enterococci invitro

Vancomycin-resistant enterococci (VRE) may be spread within a hospital via the contaminated hands of the healthcare worker. Effective hand disinfectan ts are necessary to break chains of transmission. We determined the bacteri cidal activity of 1-propanol, chlorhexidine digluconate (0.5 and 4%). Steri llium(R) (45% 2-propanol, 30% 1-propanol and 0.2% mecetronium etilsulphate) , Skinsept F(R) (70% 2-propanol, 0.5% chlorhexidine digluconate and 0.45% h ydrogen peroxide) and Hibisol(R) (70% 2-propanol and 0.5% chlorhexidine glu conate) against 11 clonally distinct enterococcal isolates in a quantitativ e suspension test. Four isolates were vancomycin susceptible, four were van A and the remainder vanB positive. Eight isolates were identified as Entero coccus faecium, two as Enterococcus faecalis and one as Enterococcus gallin arum. The investigator was blinded to the species and the genotype. Four pa rallel experiments were carried out for each isolate, each preparation, eac h dilution and each reaction time. 1-Propanol (60%), Sterillium, Skinsept F and Hibisol were all highly bactericidal after 15 and 30 a against VRE and vancomycin-susceptible enterococci (VSE) with reduction factors (RF) > 6.4 , even in dilution of 50% (v/v). No significant difference was observed bet ween vanA isolates, vanB isolates and VSE. Chlorhexidine digluconate (0.5% and 4%) was found to be less bactericidal after 30, 60 and 300 sec (RF less than or equal to 2.5). The vanB genotype isolates were found to be signifi cantly more susceptible to chlorhexidine(0.5%) than the vanA isolates (60 s ec; one-way ANOVA model; P = 0.05). After 300 sec the vanB genotype isolate s were found to be significantly more susceptible to chlorhexidine (0.5%) t han the other two genotype isolates (P = 0.016). The vanA isolates were fou nd to be significantly more susceptible to chlorhexidine (4%) than the vanB isolates (300 s; P = 0.024). E, faecium was found to be less susceptible t o chlorhexidine than E. faecalis at all concentrations and reaction times, but significant differences between RF were only observed at 60 sec for bot h chlorhexidine concentrations (P < 0.05; t-test for independent samples). Propanol is much more effective against enterococci than chlorhexidine and combination of the two may be useful in providing an immediate and long las ting effect.