Modelling vaporised hydrogen peroxide efficacy against mono-species biofilms

F Watson,S A Wilks,C W Keevil,J Chewins

doi:10.1038/s41598-018-30706-0

F Watson, S A Wilks + Show 2 more

Open Access

https://doi.org/10.1038/s41598-018-30706-0

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Abstract

This pilot study investigates a novel approach towards efficacy testing of antimicrobial cleaning agents; focusing primarily on hydrogen peroxide vapour (HPV). Contaminated surfaces are recognised modes of pathogen transmission within healthcare environments and increase the risk of pathogen acquisition in newly admitted patients. Studies have shown these pathogens can survive on surfaces for extended periods of time in spite of cleaning. This resilience is characteristic of biofilm formation and recent publications have identified their presence in hospitals. In this study, biofilm models comprised of multidrug-resistant organisms (MDROs) were generated using a drip flow reactor and exposed to HPV decontamination. The MDROs included Acinetobacter baumannii, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. Upon exposure, samples were periodically removed and enumerated to generate kill curves for each species. Consequently revealing any inherent resistances; such as catalase-producing organisms which expressed reduced susceptibility. Epifluorescence microscopy revealed an abundance of viable and non-viable microcolonies before and after decontamination, respectively. Greater than 6-Log10 reduction was achieved within a 100 minutes exposure time. This pilot study puts forward a potential methodology for testing antimicrobial agents against biofilms and supports the efficacy of HPV.

Highlights

Multi-drug resistant organisms (MDROs) are a growing threat to public health globally[1]
The result of our investigation suggests Hydrogen peroxide vapour (HPV) causes massive disruption in both microcolonies and extracellular polymeric substances (EPS) matrix within the biofilm community. This pilot study demonstrates a novel approach to efficacy testing for hospital disinfectants; in this instance HPV upon mono-species biofilms
This model showed that viable strains of high concentration multidrug-resistant organisms (MDROs) in biofilms subjected to periods of desiccation are inactivated upon exposure to HPV

Summary

Introduction

Multi-drug resistant organisms (MDROs) are a growing threat to public health globally[1]. It can be suggested that a link exists between biofilm incidence and the difficulties with managing MDROs or hospital-acquired infections (HAIs) in a healthcare setting It questions why routine cleaning disinfectants, such as hypochlorites, with proven efficacy using accepted standard tests against planktonic organisms are failing to achieve the desired results[7]. As with most decontamination processes the literature used to support its efficacy is generally associated with planktonic organisms deposited onto a dry surface[8,9,10] The aim of this pilot study was to assess the efficacious properties of hydrogen peroxide against mono-species biofilms in a dry state; creating a more representative challenge of a contaminated clinical surface

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