title: Diversity and Persistence of Salmonella enterica Strains in Rural Landscapes in the Southeastern United States.
abstract: Salmonellosis cases in the in the United States show distinct geographical trends, with the southeast reporting among the highest rates of illness. In the state of Georgia, USA, non-outbreak associated salmonellosis is especially high in the southern low-lying coastal plain. Here we examined the distribution of Salmonella enterica in environmental waters and associated wildlife in two distinct watersheds, one in the Atlantic Coastal Plain (a high case rate rural area) physiographic province and one in the Piedmont (a lower case rate rural area). Salmonella were isolated from the two regions and compared for serovar and strain diversity, as well as distribution, between the two study areas, using both a retrospective and prospective design. Thirty-seven unique serovars and 204 unique strain types were identified by pulsed-field gel electrophoresis (PFGE). Salmonella serovars Braenderup, Give, Hartford, and Muenchen were dominant in both watersheds. Two serovars, specifically S. Muenchen and S. Rubislaw, were consistently isolated from both systems, including water and small mammals. Conversely, 24 serovars tended to be site-specific (64.8%, n = 37). Compared to the other Salmonella serovars isolated from these sites, S. Muenchen and S. Rubislaw exhibited significant genetic diversity. Among a subset of PFGE patterns, approximately half of the environmental strain types matched entries in the USA PulseNet database of human cases. Ninety percent of S. Muenchen strains from the Little River basin (the high case rate area) matched PFGE entries in PulseNet compared to 33.33% of S. Muenchen strains from the North Oconee River region (the lower case rate area). Underlying the diversity and turnover of Salmonella strains observed for these two watersheds is the persistence of specific Salmonella serovars and strain types that may be adapted to these watersheds and landscapes.
authors.affiliation: Department of Population Health, University of Georgia, Athens, Georgia, United States of America.
authors.forename: John J
authors.initials: JJ
authors.lastname: Maurer
authors.affiliation: Department of Environmental Health Science, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Gordon
authors.initials: G
authors.lastname: Martin
authors.affiliation: Department of Population Health, University of Georgia, Athens, Georgia, United States of America; Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Sonia
authors.initials: S
authors.lastname: Hernandez
authors.affiliation: Department of Population Health, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Ying
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Centers for Disease and Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Peter
authors.initials: P
authors.lastname: Gerner-Smidt
authors.affiliation: Centers for Disease and Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Kelley B
authors.initials: KB
authors.lastname: Hise
authors.affiliation: Georgia Department of Public Health, Atlanta, Georgia, United States of America.
authors.forename: Melissa
authors.initials: M
authors.lastname: Tobin D'Angelo
authors.affiliation: Department of Environmental Health Science, University of Georgia, Athens, Georgia, United States of America; Centers for Disease and Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Dana
authors.initials: D
authors.lastname: Cole
authors.affiliation: Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Susan
authors.initials: S
authors.lastname: Sanchez
authors.affiliation: Department of Geography, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Marguerite
authors.initials: M
authors.lastname: Madden
authors.affiliation: Department of Epidemiology and Biostatistics, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Steven
authors.initials: S
authors.lastname: Valeika
authors.affiliation: Department of Geography, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Andrea
authors.initials: A
authors.lastname: Presotto
authors.affiliation: Department of Environmental Health Science, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Erin K
authors.initials: EK
authors.lastname: Lipp
mesh_terms: D000818:Animals; D044822:Biodiversity; D016000:Cluster Analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D004783:Environmental Microbiology; D005843:Geography; D006801:Humans; D058889:Molecular Typing; D045483:Rivers / Q000382:microbiology; D012480:Salmonella Infections / Q000382:microbiology; D019779:Salmonella enterica / Q000145:classification* / Q000235:genetics; D015144:Southeastern United States; D014871:Water Microbiology