PULLMAN, WASH. – Travelers beware: Some Salmonella Kentucky pathogens are not the type of souvenir you want to bring home from your trip.
Researchers at Washington State University (WSU) are trying to discover why Salmonella Kentucky bugs acquired in Europe, Asia and parts of Africa are more likely to cause disease and be antibiotic resistant than those acquired domestically.
A study conducted in the laboratory of Devendra Shah, an associate professor and the Caroline Engle Distinguished Professor in Research on Infectious Diseases at WSU, looked specifically at Salmonella Kentucky and found that more than 60% of Washingtonians with a confirmed Salmonella Kentucky infection while abroad from 2004 to 2014 were resistant to fluoroquinolones, a group of antibiotics used to treat Salmonella infection.
The researchers also collected Salmonella Kentucky isolates from chickens raised in the United States, but none showed resistance to fluoroquinolones. The bacteria thrive in the gastrointestinal tracts of food animals such as chickens and cattle, and are known to cause diarrhea, abdominal pain and fever in humans.
“Quite frankly, I think we’ve just gotten lucky this drug-resistant type hasn’t popped up in the US yet,” said Rachel Soltys, a graduate student and first author of a paper on the research in the Journal of Frontiers and Sustainable Food Systems.
Soltys and Shah analyzed 15 fluoroquinolone-resistant clinical samples of Salmonella Kentucky collected by the Washington State Department of Health. They traced 11 of those cases directly to international travel to the Middle East and countries such as Tanzania, Ethiopia, Ivory Coast, Morocco, Egypt and India.
Another 140 Salmonella Kentucky samples collected from chickens in the northwestern United States and the laboratory of Jean Guard, an agriculture research scientist at the US National Poultry Research Center at the US Department of Agriculture. Those samples were compared with more than 400 publicly available genome sequences of Salmonella Kentucky from various parts of the world.
“When we compared our Salmonella Kentucky sequences to the international isolates, it corroborated with what we had learned from the Washington State Department of Health epidemiology data and confirmed that the patients had picked up infection when they were traveling,” Soltys said.
Salmonella Kentucky is one of the most common Salmonella types found in domestic poultry, according to Shah, although the pathogen causes less than 100 cases of illness per year in the United States. However, reported cases would likely increase with case patients experiencing symptoms severe enough to warrant medical intervention if fluoroquinolone-resistant Salmonella Kentucky were to become endemic in the United States.
“One, you’re likely not going to recover with antibiotics,” Shah said. “Two, you’re going to disturb your normal bacteria in your body, and it can make your infection worse.”