Chemicals in gills could be used to create surfaces that kill bacteria

 Chemicals found in fish gills could be the key to engineering surfaces that kill bacteria responsible and hospital-acquired infections, a new study claims.
Living in an environment teaming with bacteria and fungi, fish have evolved powerful defences against water-borne pathogens, including antimicrobial peptides located in their gills.
Researchers at Worcester Polytechnic Institute in Massachusetts are studying the bio-mechanics of one of those peptides with the hope adapting it to create engineered surfaces that kill bacteria.

Atlantic Salmon: Living in an environment teaming with bacteria and fungi, fish have evolved powerful defences against water-borne pathogens, including antimicrobial peptides located in their gills

The research team, led by Terri Camesano, professor of chemical engineering, believe their findings, published in the journal ACS Applied Materials & Interfaces, could revolutionise materials used in kitchens and hospitals.
'Fish have a wonderful solution for blocking bacterial and fungal infections,' Professor Camesano said. 'In this study, we are working to better understand the biochemical mechanics of that process.'


As fish filter water through their gills to extract oxygen, antimicrobial peptides (AMPs), including Chrysosphin-1, trap and kill pathogens before they can invade the fish's bloodstream.
Scientists around the world have been exploring the potential use of these molecules to prevent human infections.
For their study, the WPI team attached AMPs to silicon and gold surfaces using two different approaches and measured the bound peptides' ability to kill the bacterial pathogen E. coli.
In the first method, the AMPs were absorbed directly onto gold and silicon crystals, forming a single layer of molecules with the AMPs lying flat on the surface.
In the second method, the tips of the AMPs were attached to the surfaces with a glue-like substance so that the peptides rose vertically, like blades of grass extending up from the ground.
Surfaces with both AMP configurations were cultured with E. coli cells. Results showed that when the AMPs lay flat they killed 34 per cent of the bacteria in the culture, but when they stood up vertically they killed 82 per cent.

Fluorescence microscopy images of the E. coli. cultures: The green cells are alive, while the cells in red are dead. On the left, the peptides were bound flat on the silicon crystals. On the right, the peptides were bound vertically

'The hypothesis is that when peptides are attached vertically to the surfaces, they are better able to move and bend so they take on a shape that is more effective in binding to and disrupting the E.coli cells,' Professor Camesano said.
Gold and silicon surfaces were selected for the current study because their chemical properties are well-suited for AMP binding, she added.
Her team now hopes to adapt the process to other materials that would have greater utility in food preparation and healthcare like titanium, stainless steel and plastic.
'What is also notable about this study is that it is the work of undergraduates,' Professor Camesano said.
'They've done excellent work here that will inform future graduate studies in our lab.'