Efficacy of common disinfectants used in Malaysia against isolates of vancomycin-resistant enterococci (VRE) on surfaces simulating poultry farm environment

Abstract

Background: Vancomycin-resistant enterococci (VRE) are significant causes of hospital-acquired infections and may persist in farm environments, posing a risk of transmission. Their resistance to multiple antimicrobials makes effective disinfection essential, particularly on surfaces contaminated with organic matter. Objective: This study was conducted to assess the efficacy of three disinfectants (Lindores-30 (Iodophor), (Omnicide Glutareldehyde/Quarternary Ammonium Compound), and Ecos Timsen (Quarternary Ammonium Compound) applied at recommended in-use concentrations against Enterococcus faecalis and Enterococcus faecium isolates from chickens and healthy farm workers. Methods: The influence of surface type (stainless steel and wood) and organic soiling on disinfectant performance was evaluated according to the European surface test protocol (EN 14349), microbiocidal effect (ME) was measured under clean and soiled conditions. Results: Under clean conditions, all disinfectants showed moderate activity, with ME values ranging from 2 to 5. Ecos Timsen was most effective against E. faecalis on stainless steel (ME: 5.29 ± 1.44), while Omnicide was least effective (ME: 2.38 ± 0.58). On wooden surfaces, Omnicide had the highest ME (3.53 ± 0.49) for E. faecalis. Efficacy declined significantly under soiled conditions. On stainless steel, Omnicide had the highest ME (2.43 ± 0.57) for E. faecalis, while Ecos Timsen was least effective against E. faecium (ME: 1.53 ± 1.01). On wood, Ecos Timsen performed best (ME: 2.27 ± 0.58), and Lindores-30 was least effective (ME: 1.11 ± 0.49). Conclusions: The disinfectants tested were insufficient to eliminate VRE, especially under soiled conditions. Surface type and organic contamination significantly influenced efficacy, underscoring the need for enhanced disinfection protocols in veterinary and agricultural settings.