%0 Journal Article
%T Distribution and Genetic Diversity of Salmonella enterica in the Upper Suwannee River
%A Masoumeh Rajabi
%A Melissa Jones
%A Michael Hubbard
%A Gary Rodrick
%A Anita C. Wright
%J International Journal of Microbiology
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/461321
%X The Suwannee River spans the Florida/Georgia border to the Gulf of Mexico, and contributes to regional irrigation and recreational activities. Association of Salmonella enterica with these resources may result in the contamination of produce and disease outbreaks. Therefore, surface water was examined for the distribution of S. enterica at multiple time points from 4 sites on the upper Suwannee River. Isolates were confirmed by detection of the invA gene, and 96% of all samples were positive for the bacterium. Most probable number enumeration ranged from <18 to 5400£¿MPN/100£¿mL. Genetic diversity of these isolates ( ) was compared to other environmental ( ) or clinical ( ) strains and to an online library ( ) using DiversiLab rep-PCR. All strains showed >60% similarity and distributed into 16 rep-PCR genogroups. Most (74%) of the Suwannee River isolates were clustered into two genogroups that were comprised almost exclusively (97%) of just these isolates. Conversely, 85% of the clinical reference strains clustered into other genogroups. However, some Suwannee River isolates (12%) were clustered with these primarily clinically-associated genogroups, supporting the hypothesis that river water can serve as a disease reservoir and that pathogenic strains may persist or possibly originate from environmental sources. 1. Introduction Nontyphoidal salmonellosis is the leading cause of bacterial foodborne illness in the US and contributed to approximately 33% of all foodborne-related deaths in 2009 [1]. The disease is characterized by a gastroenteritis that is associated with a wide range (>2500) of Salmonella enterica serotypes [2]. Historically, disease reservoirs for Salmonella were primarily attributed to contaminated poultry meat and eggs, but other sources include soil, factory surfaces, animal feces, and raw meats [3, 4]. More recently, orange juice [5¨C8] and other produce products [9¨C12] have been increasingly implicated as the source of salmonellosis outbreaks. Moreover, the number of cases per outbreak is greater for vegetables than for any other product [13]. Irrigation water may play an important role in contaminating soil and produce with Salmonella [14, 15]. Storm water runoff and septic tanks are known contributors of pathogens to surface water [16, 17], but rain events may also aid in the transport of pathogens from environmental sources in forested and grassed buffer zones into farm ponds [18]. Laboratory assays have demonstrated the potentiality of pathogen uptake through the roots [19] and flowers of edible plants [20], and Salmonella from
%U http://www.hindawi.com/journals/ijmicro/2011/461321/