Investigation of Pseudomonas aeruginosa biofilm formation within washing machines using novel nanosensor technology

Abstract

Biofilms are communities of microorganisms that attach to various surfaces and are widely associated with infections. Our investigation is focussed on a current and growing concern: the formation of biofilms in washing machines. Many countries wash clothes at reduced temperatures (30°C to 40°C) rather than at higher temperatures above 60°C that would kill the bacteria. Survival of the bacteria is associated with biofouling, malodour and an increased infection risk due to the distribution of human pathogens such as Pseudomonas aeruginosa, one of the predominant bacteria found in washing machines. Little is known about environmental microniches present in biofilms. Here, we focus on the pH variation throughout P. aeruginosa biofilms knowing that the pH can influence biofilm formation and could be an important aspect for the prevention of biofilms. We use novel pH-sensitive optical nanosensors that penetrate P. aeruginosa biofilms and emit fluorescence in response to pH variation. Using time lapse imaging, pH changes were tracked in real time at a single cell level which will ultimately facilitate monitoring of environmental changes induced as biocides penetrate biofilms. We also look at the isolation and identification of P. aeruginosa from household washing machines. Whole genome analysis was performed to identify different genomic features relevant to antimicrobial resistance (AMR) and biofilm formation. Furthermore, testing of different washing detergent formulations revealed a range of abilities to disrupt biofilm formation or kill P. aeruginosa, which will facilitate the development of more effective washing agents to limit the emergence of AMR within biofilms.

Removal of eDNA from fabrics using a novel laundry DNase revealed using high-resolution imaging

“…Laundry relevant bacteria can be introduced onto textiles through wearing, washing and laundering processes 1 , 26 – 28 . The bacteria eventually build up biofilms and studies showed that an average 0.22 ± 0.1 g of eDNA per gram of cellular DNA, is produced by Pseudomonas biofilms 29 .…”

Biofilms as Battlefield Armor for Bacteria against Antibiotics: Challenges and Combating Strategies

“…At that stage, the biofilms grow in thickness and are practically visible, showing the maximum tolerance to antibiotics. Important properties of biofilm-growing bacteria are different from those of planktonic bacteria, and this has significant diagnostic and therapeutic consequences [18]. However, the development of biofilms solely depends on the type of gene, which each expresses differently to different types of antibiotics.…”