UGA researchers have determined that various freshwater sources in Georgia could feature levels of salmonella that pose a risk to humans. The study recently was featured in the journal PLOS One.
Faculty and students from four colleges and five departments partnered with colleagues from the Centers for Disease Control and Prevention and the Georgia Department of Public Health to establish whether strains of salmonella exhibit geographic trends that might help to explain differences in rates of human infection.
“In this study, salmonella isolated from water and wildlife were collected over a period of 10 years from distinct rural areas in Georgia, both geographically—north versus south—and in terms of prevalence of salmonellosis in humans—lower versus higher,” said study co-author Erin Lipp, a professor of environmental health sciences in the UGA College of Public Health.
Salmonella infections are one of the top causes of gastrointestinal disease in the U.S., and while agencies have made progress in reducing foodborne transmission of the pathogen, other infection sources, including exposure to water, have not been examined as thoroughly.
To complete this research, the scholars collected samples from two different geographic regions of Georgia: the low-lying coastal plain and the piedmont, which is higher in elevation.
Data was collected from six stations in the Little River watershed near Tifton, which has one of the highest case rates for salmonellosis in the state, and along the North Oconee River in Jackson County, a lower case rate area in Georgia. Water samples from all sites were gathered from December 2010 to November 2011. Samples from surrounding wildlife also were collected, and archived samples from these areas dating back to 2005 also were included.
The team found that water sources could be an underestimated source of salmonella exposure to humans. Though the frequency that salmonella was found in north and south Georgia was similar, salmonella strains with DNA fingerprints matching those found in humans were more commonly found in south Georgia.
UGA researchers who collaborated with John Maurer, the paper’s principal author and a professor of population health in UGA’s College of Veterinary Medicine, and Lipp on this project include Gordon Martin and Steven Valeika from the College of Public Health; Dana Cole from the College of Public Health and CDC; Ying Cheng and Susan Sanchez from the College of Veterinary Medicine; Sonia Hernandez from the College of Veterinary Medicine and the Warnell School of Forestry and Natural Resources; and Marguerite Madden and Andrea Presotto from the Franklin College of Arts and Sciences.