title: Identification of environmental reservoirs of nontyphoidal salmonellosis: aptamer-assisted bioconcentration and subsequent detection of  salmonella  typhimurium by quantitative polymerase chain reaction.
abstract: In this study, identification of environmental reservoirs of  Salmonella enterica  subsp.  enterica  serovar Typhimurium (abbreviated as  Salmonella  Typhimurium) in sediments, water, and aquatic flora collected from the Ganges River (Ganges riverine material) was carried out by adopting a two-step strategy. Step 1 comprised a selective serovar-specific capture of  Salmonella  Typhimurium from potential reservoirs. Step 2 involved culture-free detection of selectively captured  Salmonella  Typhimurium by ttr gene-specific molecular beacon (MB) based quantitative polymerase chain reaction (q-PCR). The ttr gene-specific MB designed in this study could detect 1 colony-forming unit (cfu)/PCR captured by serovar-specific DNA aptamer. Sediments, water, and aquatic flora collected from the Ganges River were highly contaminated with  Salmonella  Typhimurium. The preanalytical step in the form of serovar-specific DNA aptamer-based biocapture of bacterial cells was found to enhance the sensitivity of the fluorescent probe in the presence of nonspecific DNA . Information about the presence of environmental reservoirs of  Salmonella  Typhimurium in the Ganges River region may pave the way for forecasting and management of nontyphoidal salmonellosis in south Asia.
authors.affiliation: Environmental Microbiology, CSIR- Indian Institute of Toxicology Research, Mahatma Gandhi Marg, Uttar Pradesh, India.
authors.forename: Anurag
authors.initials: A
authors.lastname: Jyoti
authors.forename: Poornima
authors.initials: P
authors.lastname: Vajpayee
authors.forename: Gulshan
authors.initials: G
authors.lastname: Singh
authors.forename: Chandra Bali
authors.initials: CB
authors.lastname: Patel
authors.forename: Kailash Chand
authors.initials: KC
authors.lastname: Gupta
authors.forename: Rishi
authors.initials: R
authors.lastname: Shanker
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012480:Salmonella Infections / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D052157:Aptamers, Nucleotide