Date of Award
Doctor of Philosophy
Non-typhoidal Salmonella (NTS) infection is one of the major causes of diarrheal disease throughout the world. Recently, an increase in trend of human S. Newport, S. Javiana, and S. Mississippi infection has been observed in Tennessee. The exact reason for the increase of the NTS infection by these three serotypes is not known. The sources of human S. Javiana infections are not well characterized. This study performed a systematic literature review to identify potential sources of human S. Javiana infection based on available scientific evidence. This study identified the food (such as tomatoes, watermelons, paprika-spice, and cheese), drinking well water, and non-foodborne (such as animal contact) exposures are responsible for the transmission of human S. Javiana infection.The current study explored the potential risk factors associated with any of the above mentioned three Salmonella serotypes among data from FoodNet and TDH consisting of 2,757 culture-confirmed salmonellosis cases from Tennessee during 2013 through 2015. A case-case analysis was performed to identify potential risk factors for human NTS infections caused by any of the three selected serotypes. This study identified the following risk factors that were independently associated with the cases: recreational water [OR adjusted= 1.7 (95% CI 0.9, 3.0)], dog [OR adjusted= 1.6 (95% CI 0.9, 2.7)], pet treats [OR adjusted= 3.0 (95% CI 1.6, 5.5)], visit to a farm [ORadjusted = 2.3 (95% CI 0.9, 6.0)], ice cream [OR adjusted= 1.5 (95% CI 0.9, 2.4], and frozen pizza [OR adjusted= 1.5 (95% CI 0.9, 2.5)]. This study also demonstrated that the Salmonella serotypes assessed in this study harbors antibiotic resistance characteristics as well as several virulence genes. Additionally, the current study identified the association between antibiotic resistance and virulence genes of Salmonella isolates. The virulent gene, ssaQ, was observed to be significantly associated with antibiotic-resistant Salmonella [2 (df=1) = 12.16, P idk adjusted = 0.019]. Further investigation with larger sample is needed to better understand this association. To conclude, this study points out the need for routine surveillance of human NTS infections, as well as increased public awareness and practice of hand hygiene to prevent the occurrence of the infection.
Dissertation or thesis originally submitted to ProQuest
Mukherjee, Nabanita, "SOURCE ATTRIBUTION, ANTIBIOTIC RESISTANCE AND VIRULENCE PROPERTIES OF SALMONELLA SEROTYPES ISOLATED FROM CLINICALLY DIAGNOSED HUMAN SALMONELLOSIS CASES FROM TENNESSEE" (2018). Electronic Theses and Dissertations. 2935.