Analysis of Salmonella enterica Isolated from a Mixed-Use Watershed in Georgia, USA: Antimicrobial Resistance, Serotype Diversity, and Genetic Relatedness to Human Isolates

Abstract

Salmonella has been traditionally considered a foodborne pathogen, as it is one of the most common etiologies of foodborne illnesses worldwide; however, recent Salmonella outbreaks attributed to fresh produce and water suggest a potential environmental source of Salmonella that causes some human illnesses. Here, we investigated the prevalence, diversity, and antimicrobial resistance of Salmonella isolated from a mixed-use watershed in Georgia, USA, in order to enhance the overall understanding of waterborne Salmonella .

Prevalence and whole‐genome sequencing characterization of Salmonella in urban karst groundwater and predominantly groundwater‐fed surface waters for serotypes and antimicrobial resistance

“…Seasonal effect on Salmonella prevalence is consistent with previous studies (Cho et al., 2022, 2020). Importantly, it has been reported that seasonal pattern of Salmonella prevalence in the aquatic environment coincides with increased incidence of human infections, indicating that water plays a significant source of human infections directly as a vector, or indirectly as a reservoir, for Salmonella (Cho et al., 2020).…”

“…For example, monitoring activities can target the three sampling sites (Bypass Cave well, Durbin well, and the Barren River) that contributed over half of Salmonella ‐positive samples in the month of November and summer and fall seasons. The higher prevalence of Salmonella in the mainly groundwater‐fed surface water in the Bowling Green, KY, study is consistent with previous studies reporting Salmonella from surface waters with differing land use (Cho et al., 2022; Hubbard et al., 2020; Rocha et al., 2022). Salmonella was reported from all nine surface water samples, and 77% ( n = 13) of groundwater samples collected near poultry farms (Hubbard et al., 2020).…”

“…Salmonella was reported from all nine surface water samples, and 77% ( n = 13) of groundwater samples collected near poultry farms (Hubbard et al., 2020). A 3‐year study (Cho et al., 2022) that seasonally collected water samples from 105 rivers and streams from a mixed‐use watershed in Geogia reported Salmonella from 70% of the total samples. Together, the findings indicate the importance of surface water, particularly rivers that serve as a source of drinking water, for water quality monitoring for pathogens such as Salmonella .…”

“…From the water samples tested, serotypes that are commonly associated with human infections were identified. Out of ≈2600 Salmonella serotypes identified to date (Brown et al., 2021; Cho et al., 2022), only about 100 of them are implicated in human infections (Cho et al., 2022). Nine serotypes (Newport, Typhimurium, Muenchen, Thompson, Saintpaul, Bareilly, Agona, Paratyphi B var.…”

“…Studies have mainly focused on Salmonella contamination in surface waters (Bell et al, 2015;Cho et al, 2022Cho et al, , 2020Gorski et al, 2011), and those reporting from groundwater are generally scarce and usually involve groundwater wells directly used for public consumptions (Hynds et al, 2014;Stokdyk et al, 2020); however, studies in karst areas involving other features, such as springs, cave streams, and groundwater-fed surface streams, are rare. The current study provides information on the Salmonella water contamination encompassing wells, springs, and cave stream features of the groundwater system and predominantly groundwaterfed surface water.…”