TY - JOUR

T1 - Susceptibility of vancomycin-resistant and –sensitive Enterococcus faecium obtained from Danish hospitals to benzalkonium chloride, chlorhexidine and hydrogen eroxide biocides

AU - Alotaibi, Sulaiman M.I.

AU - Ayibiekea, Alafate

AU - Pedersen, Annemette Frøling

AU - Jakobsen, Lotte

AU - Pinholt, Mette

AU - Gumpert, Heidi

AU - Hammerum, Anette M.

AU - Westh, Henrik

AU - Ingmer, Hanne

PY - 2017/12

Y1 - 2017/12

N2 - Purpose. In Danish hospitals, the number of infections caused by vancomycin-resistant Enterococcus faecium (VRE faecium) has dramatically increased in recent years. Hospital disinfectants are essential in eliminating pathogenic microorganisms, and reduced susceptibility may contribute to hospital-associated infections. We have addressed whether clinical VRE faecium display decreased biocide susceptibility when compared to vancomycin-sensitive Enterococcus faecium (VSE faecium) isolates. Methodology. In total 12 VSE faecium and 37 VRE faecium isolates obtained from Danish hospitals over an extended time period were tested for susceptibility towards three commonly applied biocides, namely benzalkonium chloride, chlorhexidine and hydrogen peroxide. Results. For benzalkonium chloride, 89% of VRE faecium strains had a minimal inhibitory concentration (MIC) of 8mg l–1, whereas for VSE faecium, only 25% of the strains had an MIC of 8mgl–1. For chlorhexidine, the MIC of 95% of VRE faecium strains was 4 mgl–1 or higher, while only 33% of VSE faecium strains displayed MIC values at the same level. In contrast, both VRE and VSE faecium displayed equal susceptibility to hydrogen peroxide, but a higher minimal bactericidal concentration (MBC) was found for the former. The efflux activity was also assessed, and this was generally higher for the VRE faecium strains compared to VSE faecium. Conclusion. VRE faecium from Danish hospitals demonstrated decreased susceptibility towards benzalkonium chloride and chlorhexidine compared to VSE faecium, where the use of chlorhexidine is particularly heavy in the hospital environment. These findings suggest that biocide tolerance may characterize VRE faecium isolated in Danish hospitals.

AB - Purpose. In Danish hospitals, the number of infections caused by vancomycin-resistant Enterococcus faecium (VRE faecium) has dramatically increased in recent years. Hospital disinfectants are essential in eliminating pathogenic microorganisms, and reduced susceptibility may contribute to hospital-associated infections. We have addressed whether clinical VRE faecium display decreased biocide susceptibility when compared to vancomycin-sensitive Enterococcus faecium (VSE faecium) isolates. Methodology. In total 12 VSE faecium and 37 VRE faecium isolates obtained from Danish hospitals over an extended time period were tested for susceptibility towards three commonly applied biocides, namely benzalkonium chloride, chlorhexidine and hydrogen peroxide. Results. For benzalkonium chloride, 89% of VRE faecium strains had a minimal inhibitory concentration (MIC) of 8mg l–1, whereas for VSE faecium, only 25% of the strains had an MIC of 8mgl–1. For chlorhexidine, the MIC of 95% of VRE faecium strains was 4 mgl–1 or higher, while only 33% of VSE faecium strains displayed MIC values at the same level. In contrast, both VRE and VSE faecium displayed equal susceptibility to hydrogen peroxide, but a higher minimal bactericidal concentration (MBC) was found for the former. The efflux activity was also assessed, and this was generally higher for the VRE faecium strains compared to VSE faecium. Conclusion. VRE faecium from Danish hospitals demonstrated decreased susceptibility towards benzalkonium chloride and chlorhexidine compared to VSE faecium, where the use of chlorhexidine is particularly heavy in the hospital environment. These findings suggest that biocide tolerance may characterize VRE faecium isolated in Danish hospitals.

KW - Benzalkonium chloride

KW - Biocide tolerance

KW - Chlorhexidine

KW - Enterococcus faecium

KW - Nosocomial infection

KW - VRE

KW - VSE

U2 - 10.1099/jmm.0.000642

DO - 10.1099/jmm.0.000642

M3 - Journal article

C2 - 29134935

AN - SCOPUS:85037731167

VL - 66

SP - 1744

EP - 1751

JO - Journal of Medical Microbiology

JF - Journal of Medical Microbiology

SN - 0022-2615

IS - 12

M1 - 000642

ER -