Monash University new surface on medical instruments reduces infection

Monash University

Researchers at Monash University have engineered new antimicrobial surfaces that can reduce the number of bacteria which forms on medical instruments, like catheters, reducing the risk of patient infection. 

The study demonstrated how 3D engineered surfaces can prevent the three most common urinary tract infections (UTIs) from initially forming while catheters are in use. These infections are Escherichiacoli (E.coli), Pseudomonas aeruginosa and Klebsiellapneumoniae. 

The research team at Monash University’s Department of Mechanical and Aerospace Engineering and the Centre to Impact AMR was led by Dr Victor Cadarso. Their result was surfaces with smooth, 3D micro features that reduced the potential of large numbers of harmful bacteria attaching – an improvement on traditional surfaces with sharp, cross-sectional features. 

Once tested, the surfaces showed a reduced formation of both bacteria and biofilm. One of the surfaces presented excellent properties against E.coliK.pneumoniae and P. aeruginosa with 55 per cent, 69 per cent and 68 per cent less bacteria attached; and 53 per cent, 77 per cent and 66 per cent less microcolonies formed, respectively. 

“Using E.coli as an example, we found bacterial cells that form on surfaces do so mostly on the sharp corners. By removing these sharp features, the bacteria can no longer colonise the surface as effectively. This same effect has been demonstrated for the two other pathogens in this study,” Monash Department of Mechanical and Aerospace Engineering researcher Sara Ghavamian said, who created the surfaces.   

“High-touch surfaces within hospitals, such as catheters and ventilators, are a significant source of microbial spread and healthcare-associated infections. Infection control through physically altering the micro architecture of these surfaces, rather than the traditional use of chemical agents, is not only a more durable approach but also an effective strategy for combating antimicrobial resistance.”   

Via an extensive screening process, it was identified the sharp corners of the vertical side walls in conventional surfaces gave bacteria hiding spots to prevent fluids from washing them away. By smoothing these corners, the hypothesis was that the bacteria would have nowhere to hide. 

“After equivalent incubation periods with the same bacteria, we discovered that while the micropatterned surfaces were indeed successful in reducing the number of microcolonies formed they, problematically, increased the number of attached bacteria compared with traditional micro-flat surfaces,” Ghavamian said. 

“Opposite the conventional sharp micropatterned surfaces, our smooth design demonstrated a simultaneous decrease in both the number of bacterial attachment and microcolony formation compared to the standard flat surfaces.  

“Developing strategies to prevent the bacterial colonisation of surfaces, such as catheters, without requiring antimicrobial drugs or chemicals is critical to stop biofilm formation and the potential spread of harmful diseases.” 

UTIs are the most common type of healthcare-associated infections, identified by the World Health Organisation (WHO) as an urgent global health threat. It’s estimated that 13,000 people die globally each year from UTIs and a further 700,000 die from associated antimicrobial resistance infections, due to the resistance to antibiotics and current sterilisation methods. 

With researchers from Monash University’s Department of Microbiology also involved, the study was partially conducted at the Melbourne Centre for Nanofabrication, the Monash Centre for Electron Microscopy, the Ramaciotti Centre for Cryo-Electron Microscopy, the Monash Centre to Impact AMR and Monash University Biomedicine Discovery Institute. 

The Monash University study was published in the international journal ACS Applied Materials and Interfaces. 

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