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Searching for causes of Salmonella infections

By Dale Johnson Posted: October 26, 2015 6:00 a.m.

Dr. Andrew Cameron says by finding out how Salmonella gets started could lead to ways of reducing such infections.
Dr. Andrew Cameron says by finding out how Salmonella gets started could lead to ways of reducing such infections. Photo courtesy - Trevor Hopkin of U of R Photography.

Salmonella is a major cause of food poisoning throughout the world. A person can get Salmonella by eating a variety of foods; in North America it’s usually spread through vegetables contaminated with invisible amounts of animal feces, through undercooked poultry, or through cross-contamination of foods in the kitchen. Of the over 1,000,000 infections annually in North America, around 500 are deadly.  Salmonella is estimated to kill 700,000 people around the world each year, similar to the burden of malaria.

Dr. Andrew Cameron, an assistant professor of biology at the University of Regina, is trying to find out more about the causes of Salmonella infections.

“Salmonella is a deadly pathogen that causes infections in all parts of the world. Yet, when someone swallows this bacterium it is not inevitable that they will become sick. This is because Salmonella needs to express special genes that allow it to invade our tissues and cause infection. If Salmonella doesn’t detect specific conditions in our gut, it will not start an infection. Unfortunately, we don’t know what conditions Salmonella is sensing and how it is sensing them. I seek to discover the conditions in the gut that trigger Salmonella to initiate infection and cause disease,” Dr. Cameron explains.

Dr. Cameron’s research team includes three graduate students and three undergraduate research students. As well, a professor from Dublin, Ireland, spends three to four weeks each year working in his lab. Dr. Cameron has collaborations with researchers across Canada, as well as the U.S.A., the U.K., Ireland, and Switzerland.

“To study Salmonella, we grow the bacterium in the lab and expose it to conditions that approximate features it might encounter in the human intestine. We monitor the genetic responses in the bacterium and then dissect the gene networks that allow the bacterium to cause infection,” he says.

Dr. Cameron says they are working to understand two aspects that could have significant public health implications.

“First, finding non-antibiotic therapies to reduce infection by determining how and why Salmonella initiates infection in the intestine, and second, determining how antibiotic resistance emerges and spreads in bacteria. The former will inform us on how to reduce infection through natural interventions like good nutrition and intestinal health, and the latter is important for the critical issue of how and why so many antibiotic-resistant bacteria are spreading in our environments and healthcare facilities,” he says.

Dr. Cameron’s research is funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), Saskatchewan Health Research Foundation (SHRF), Canadian Foundation for Innovation (CFI) and the University of Regina.