TRU’s antibiotic superteam

A trio of professors has undertaken research into antibiotics and methods to combat superbugs

Mark Hendricks, Science & Technology Editor Ω

A first-year graduate student in the masters of environmental science program and is working with Donkor to help with lantibiotic research. Mark Hendricks/The Omega

Erika Dufort is a first-year graduate student in the masters of environmental science program and is working with Donkor to help with lantibiotic research. Mark Hendricks/The Omega

Antibiotic-resistant superbugs are a growing fear in today’s pharmaceutical-reliant society. The temptation to take medication, even when it’s not really needed, is causing bacteria to evolve right before our eyes and develop resistances to many modern medicines.

Three TRU professors, Heidi Huttunen-Hennelly, Kingsley Donkor and Naowarat “Ann” Cheeptham, are working to combat superbugs by pioneering new antibiotic research with the help of a handful of dedicated science students.

“We all have expertise in different areas, so we work well together,” said Huttunen-Hennelly, associate professor of chemistry and the team’s expert in peptide synthesis. “I know a lot about protein and peptide structure, Kingsley is great on the analytical side and Ann is great on the microbiology side.”

Huttunen-Hennelly’s specialty is in designing antimicrobial peptides. Peptides are short chains of amino acids that, when designed in certain ways, will help combat pathogenic bacteria.

“We’ve made maybe two dozen peptides now that have shown quite good activity,” Huttunen-Hennelly said. “Even against the superbugs you hear about.”

Despite the success so far, it’s uncertain whether or not any of these will ever see commercial use.

“Are we actually ever going to go to the point of trying to patent and produce some of these peptides?” Huttunen-Hennelly pondered. “It’s just such a costly market, you’d almost want some biotech company to buy your patent off of you.”

Huttunen-Hennelly’s research instead focuses on achieving a better understanding of how antimicrobial peptides work, something Huttunen-Hennelly said is merely acknowledged in the majority of papers, instead of examined.

Cheeptham studies bacteria found in caves to look for those which exhibit antimicrobial properties. Because many caves are more difficult to access, the bacteria in them, which are classified as extremophile bacteria because of the harsh conditions they live in, are not as often studied.

“We want to find something totally new, we don’t want to find another penicillin again,” Cheeptham said. “If you keep going to a place that has been extensively studied, you’ll find a known compound. We want something totally new.”

peptide-synthesizer

This peptide synthesizer is the key component in Huttunen-Hennelly’s research and is what lets her artificially create peptides. Mark Hendricks/The Omega

Cheeptham takes these bacteria found in caves and cultures them under ideal conditions in the hopes of producing a usable antimicrobial agent.

“Basically I am a farmer, but I am a microbial farmer,” Cheeptham said. “I grow them in the lab and then try to see whether they produce certain things that I want, that they don’t necessarily normally produce when they live in the caves.”

Cheeptham has had great success with this, finding a relatively large number of bacteria that have antimicrobial properties. In an underwater cave that Cheeptham examined, nine of the 266 microbes had antimicrobial properties.

Donkor’s focus is on lantibiotics, a relatively new type of antibiotic that differs from regular antibiotics in terms of chemical structures.

Despite the work Cheeptham is doing searching for antimicrobial bacteria to combat superbugs, she doesn’t want to paint the picture of bacteria as the enemy.

“I feel bad for bacteria, because when we look at bacteria, the press often calls them germs and bugs and stuff,” Cheeptham said. “Not many people know that less than one per cent of bacteria causes us to be sick, more than 99 per cent of bacteria actually helps us.”

“The primary use right now is in the dairy industry and the agriculture industry,” Donkor said. “It’s just fairly recently that it’s been recognized that lantibiotics can be effective at combating pathogenic bacteria.”

Lantibiotics are used in milk, as a chemical-free method of spraying crops and for treating diseases in livestock. They are considered safe by the Food and Drug Administration, which is why they’re used in food production.

Despite this, there’s no clear understanding of the way they work. The prevailing theory is that lantibiotics work by attaching to a structure on the outside of the cell, called lipid two, and then they create holes in the cell, leaking out vital nutrients and starving it.

“That’s the main theory, but I believe that’s not the whole story,” Donkor said. “I believe it also attacks other parts of the cell.”

Donkor’s research aims to better understand the way in which lantibiotics work to improve their effectiveness in their applications, both in the food industry and in human patients.

Donkor, Cheeptham and Huttunen-Hennelly don’t work alone though. They all work with undergraduate and graduate students in their labs. These students help with the research and gain valuable hands-on experience in the lab. Donkor calls the students an invaluable part of the research process.

“Whatever I do, I want to make sure I share the credit with my students,” Donkor said.