Assessment of novel disinfection technologies, and bacterial contamination in the healthcare setting.

Abstract

Worldwide, hundreds of thousands of healthcare acquired infections (HAIs) are reported each year. HAIs are infections that occur whilst in hospital or as a result of hospital admittance, contamination of hospitals is a source of, and allows dissemination of HAIs. In healthcare settings one of the major vectors of contamination is healthcare workers’ uniforms. As surfaces become contaminated, bacteria can then be contacted by patients (direct transmission) or staff who may then indirectly spread those bacteria to patients. Both
direct and indirect spread of bacteria could result in infection of patients ultimately resulting in increased infection rates and associated costs. A further consequence of such a scenario is the increased levels of antibiotic use, the survival of antibiotic resistant bacteria and increased prevalence of antimicrobial resistance. A pilot study was conducted at Antrim Area Hospital, Northern Health and Social Care Trust. 100 pre-shift and 100 post-shift healthcare workers’ uniforms were assessed for Staphylococcus aureus and Enterococcus spp. isolates. We found increased levels of antibiotic resistant S. aureus and antibiotic resistant Enterococcus spp. contamination on post-shift uniforms compared to zero to minimal contamination of pre-shift uniforms. A biobank of isolates was created and subsequently characterised for antibiotic sensitivity using European Union Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines – 51% of S. aureus isolates were classed multi-drug resistant. Genomic diversity
was assessed using Random Amplification of Polymorphic DNA (RAPD) – high levels of similarity was found amongst isolates. As one means of reducing uniform bioburden, we conducted analysis of a novel surface active organosilane disinfectant named Goldshield (GS). GS was marketed as a long lasting antimicrobial with residual activity to prevent (re)contamination. GS was tested against model HAI bacteria, spores and biofilms with a view to assessing its potential incorporation into infection control practices. GS technology
displayed bactericidal, sporicidal and anti-biofilm properties in laboratory testing providing rationale for an intervention where GS could be incorporated into hospital laundry and assessed for potential use in infection control.

Date of Award	Feb 2019
Original language	English
Sponsors	Department of Education and Learning (DEL)
Supervisor	Chris Gill (Supervisor) & Nigel Ternan (Supervisor)