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The Role of Benzo(c)phenanthridine Alkaloids on Swine-pathogen Interaction and the Epidemiology of Salmonella enterica

Artuso-Ponte, Valeria C
http://rave.ohiolink.edu/etdc/view?acc_num=osu1420544942

Abstract Details

2015, Doctor of Philosophy, Ohio State University, Comparative and Veterinary Medicine.
Salmonella enterica is one of the leading foodborne pathogens worldwide and consumption of contaminated pork has been associated with human salmonellosis. Pork can be contaminated with Salmonella at any point in the food chain; however, infected pigs carrying Salmonella have been identified as the most important source of Salmonella for the carcasses. Furthermore, several factors including stress and the composition of the intestinal microbiome have shown to influence the dynamics of the Salmonella infection in swine, which may explain at least partially the great variability in Salmonella shedding among pigs under natural and experimental conditions. Pre-harvest control of Salmonella is paramount to decrease the risk of carcass contamination and improve the safety of the food products. This dissertation includes 2 overarching goals containing a series of five experiments (Chapters), aimed to evaluate the effect of a novel intervention strategy to decrease Salmonella shedding by regulating stress response due to transportation. The first goal evaluated the effectiveness of Quaternary Benzo(c)phenanthridine Alkaloids (QBA) supplementation on Salmonella shedding and carcass contamination. We first developed and validated a qPCR assay to optimize the detection limit, which allowed for the detection and quantification of low numbers of Salmonella from swine feces and carcass swabs (Chapter 3). The qPCR was implemented to accurately quantify Salmonella on samples collected from pigs supplemented with QBA and non-supplemented (Chapter 4). The results showed that QBA supplementation in the feed and the drinking water resulted in a reduction in the proportion of Salmonella-infected finishing pigs as well as in the numbers of Salmonella shed through the feces after transportation to the slaughterhouse. Moreover, supplementing pigs with QBA resulted in a reduction in the level of carcass contamination with Salmonella. This first goal also showed that stress due transportation influence the dynamics of the Salmonella infection, increasing Salmonella shedding and the risk of carcass contamination. The second overarching goal (Chapters 5, 6 and 7) evaluated the effect of QBA supplementation on factors related to the host that may influence the dynamic of Salmonella in swine. The first experiment (Chapter 5) was designed to assess the effect of QBA supplementation on salivary cortisol concentrations, as a measure of stress response. Findings from this study revealed that QBA supplementation was effective in reducing the impact of stress due to transportation, as lower salivary cortisol concentrations were observed in QBA-supplemented pigs. These results served as the basis for the subsequent studies (Chapter 6 and 7) designed to evaluate the effect of QBA supplementation on the intestinal barrier function and the intestinal microbiome respectively. We hypothesized that if QBA supplementation regulates stress due to transportation, the integrity and permeability of the intestinal barrier would be improved and the intestinal microbial communities would be more stable. Accordingly, the study presented in Chapter 6 was performed to evaluate whether QBA supplementation would result in the increase of the transepithelial electrical resistance (TER) and the decrease in the permeability of the intestinal epithelium to molecular markers as compared to non-supplemented pigs. Findings showed that TER and intestinal permeability coefficients were not different between supplemented and non-supplemented pigs. However, these measurements were taken at a single point (after the pigs were slaughtered) and did not provide conclusive results as to whether stress due to transportation affected the integrity of the intestinal barrier or the potential role of QBA supplementation in ameliorating its negative impact on the intestinal barrier function. The study presented in Chapter 7 was designed to examine the intestinal microbial profiles in finishing pigs after transportation to the slaughterhouse in response to QBA supplementation. The results showed an increased microbial diversity in QBA-supplemented pigs, represented by a more even distribution of the classified phylotypes. However, based on the findings we could not prove that stress due to transportation affected the diversity of intestinal microbial populations, thus the higher microbial diversity observed in supplemented pigs are likely due to the direct effect of QBA on the microbiome or on other factors that may influence the intestinal microbiome.
Wondwossen Gebreyes (Advisor)
Steven Moeller (Committee Member)
Prosper Boyaka (Committee Member)
Paivi Rajala-Schultz (Committee Member)
216 p.
Public Health; Veterinary Services
Salmonella enterica, stress, plant alkaloids

Recommended Citations

Citations

  • Artuso-Ponte, V. C. (2015). The Role of Benzo(c)phenanthridine Alkaloids on Swine-pathogen Interaction and the Epidemiology of Salmonella enterica [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420544942

    APA Style (7th edition)

  • Artuso-Ponte, Valeria. The Role of Benzo(c)phenanthridine Alkaloids on Swine-pathogen Interaction and the Epidemiology of Salmonella enterica. 2015. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1420544942.

    MLA Style (8th edition)

  • Artuso-Ponte, Valeria. "The Role of Benzo(c)phenanthridine Alkaloids on Swine-pathogen Interaction and the Epidemiology of Salmonella enterica." Doctoral dissertation, Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420544942

    Chicago Manual of Style (17th edition)

osu1420544942
857
© 2015, some rights reserved.Creative Commons License The Role of Benzo(c)phenanthridine Alkaloids on Swine-pathogen Interaction and the Epidemiology of Salmonella enterica by Valeria C Artuso-Ponte is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by The Ohio State University and OhioLINK.