Dual-Function Antimicrobial Laundry Supplement and Textile Coating for the Decontamination of Healthcare Laundry

Background: In the UK nurses’ uniforms are domestically laundered, posing a threat of cross contamination of healthcare-associated infections. The UK Department of Health recommends washing uniforms at 60ºC, however nurses most commonly wash them at 40ºC. Bacteria survive on textiles washed at low temperatures; 4.28-4.62 log10 Escherichia coli and Staphylococcus aureus survived washing at 40ºC and cross contaminated other textiles in the wash. Antimicrobial laundry supplements could sanitise textiles and limit cross-contamination. A supplement that deposits an antibacterial coating onto textiles could also reduce contamination between washes. This study aimed to investigate a silver-based antimicrobial textile coating product (Micro-Fresh 1911) as a dual-use antimicrobial laundry supplement and textile coating. Materials/methods: Polycotton inoculated with 108 CFU/mL E. coli or S. aureus (type and clinical isolates) were washed with 2% Micro-Fresh 1911 in a domestic washing machine (40°C) and surviving microorganisms enumerated. Washes were conducted with and without soiling and biological detergent. Control washes were water alone. The antimicrobial activity of polycotton washed with Micro-Fresh 1911 at 40°C was assessed against S. aureus and E. coli using ISO 20645 and ISO 20743 methods. Controls were polycotton washed in water and textile padded with Micro-Fresh 2611. Results: Washing with Micro-Fresh 1911 reduced E. coli and S. aureus by 7.14-8.08 log10. No cells were recovered from sterile textile, whereas washing with water alone reduced E. coli and S. aureus by 2.21-4.25 log10 and resulted in 3.13-4.01 log10 CFU cross-contamination. Combining Micro-Fresh 1911 with biological detergent reduced E. coli and S. aureus by 5.56-6.65 log10. Fabric washed with Micro-Fresh 1911 was antimicrobial against E. coli and S. aureus type and clinical isolates according to ISO 20645 and ISO 20743. The antimicrobial coating remained after washing the fabric in water once at 40°C and 73°C. Conclusions: Micro-Fresh 1911 exibits antimicrobial activity in a 40ºC domestic wash and deposits an antimicrobial layer onto polycotton. Micro-Fresh could be employed as an antimicrobial laundering product to reduce microbial contamination of healthcare laundry washed at low temperatures.