Researchers at the Stanford University School of Medicine have identified a molecule that serves as natural protection against one of the most common Intestinal pathogens.
Propionate, a byproduct of metabolism by a group of bacteria called the Bacteroides, inhibits the growth of Salmonella in the intestinal tract of mice, according to the researchers. The finding may help to explain why some people are better able to fight infection by Salmonella and other intestinal pathogens and lead to the development of better treatment strategies.
The researchers determined that propionate doesn't trigger the immune response to thwart the pathogen. Instead, the molecule prolongs the time it takes the pathogen to start dividing by increasing its internal acidity.
Salmonella infections often cause diarrhea, fever and abdominal cramps. Most people recover within four to seven days. However, the illness may be severe enough to require hospitalization for some patients.
Salmonella causes about 1.2 million illnesses, 23,000 hospitalizations and 450 deaths nationwide each year, according to the Centers for Disease Control and Prevention. Most cases are caused by contaminated food.
The findings could also influence treatment strategies. Treating Salmonella infections sometimes require the use of antibiotics, which may make Salmonella-induced illness or food poisoning worse since they also kill off the "good" bacteria that keep the intestine healthy, according to Monack. Using propionate to treat these infections could overcome this limitation.
Amanda Jacobson, Lilian Lam, Manohary Rajendram, Fiona Tamburini, Jared Honeycutt, Trung Pham, Will Van Treuren, Kali Pruss, Stephen Russell Stabler, Kyler Lugo, Donna M. Bouley, Jose G. Vilches-Moure, Mark Smith, Justin L. Sonnenburg, Ami S. Bhatt, Kerwyn Casey Huang, Denise Monack. A Gut Commensal-Produced Metabolite Mediates Colonization Resistance to Salmonella Infection. Cell Host & Microbe, 2018; DOI: 10.1016/j.chom.2018.07.002
Posted by Dr. Tim Sandle, Pharmaceutical Microbiology