Search
Author
Title
Vol.
Issue
Year
1st Page

Journal of Animal Science Abstract - Physiology, Endocrinology, and Reproduction

Postmortem photonic imaging of lux-modified Salmonella Typhimurium within the gastrointestinal tract of swine after oral inoculation in vivo1

 

This article in

  1. Vol. 87 No. 7, p. 2239-2244
     
    Received: Oct 28, 2008
    Accepted: Mar 19, 2009
    Published: December 5, 2014


    2 Corresponding author(s): swillard@ads.msstate.edu
 View
 Download
 Share

doi:10.2527/jas.2008-1470
  1. K. Moulton*,
  2. P. Ryan*,
  3. D. Lay and
  4. S. Willard*2
  1. Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762; and
    Livestock Behavior Research Unit, USDA-ARS, West Lafayette, IN 47907

Abstract

The study objective was to monitor Salmonella progression by photonic detection through segments of the gastrointestinal tract after oral inoculation. Pigs (~80 kg) were inoculated orally with 3.1 or 4.1 × 1010 cfu of Salmonella Typhimurium transformed with plasmid pAK1-lux for a 6-h (n = 6) or 12-h (n = 6) incubation in vivo and then were killed for tissue harvest. Intestinal regions (duodenum, jejunum, ileum, large intestine) were divided into 5 replicates of 4 segments (5 cm) each for imaging. For each replicate, n = 2 segments of each region were intact, whereas n = 2 segments were opened to expose the digesta. Subsamples of digesta were analyzed to determine actual colony-forming units, and images were analyzed for relative light units per second. At 6 h, a greater (P < 0.05) concentration of emitting bacteria, and consequently a greater (P < 0.05) detection of photonic emissions, was observed in the small intestine than in the large intestine. The correlations (6 h) of photonic emissions in exposed segments to bacterial colony-forming units were r = 0.73, 0.62, 0.56, and 0.52 (P < 0.05) in duodenum, jejunum, ileum, and large intestine, respectively. Photonic emissions were greater (P < 0.05) in intact jejunum, ileum, and large intestine than in the duodenum after a 6-h incubation. At 12 h, a greater (P < 0.05) concentration of emitting bacteria in jejunum and ileum of exposed segments was observed than in duodenum and large intestine of exposed segments. Photonic emissions were greater in ileum than duodenum, jejunum, and large intestine of exposed segments (P < 0.05). The correlations (12 h) of photonic emissions in exposed segments to bacterial colony-forming units were r = 0.71 and 0.62 for jejunum and ileum, respectively (P < 0.05). At 12 h, a greater (P < 0.05) concentration of emitting bacteria in jejunum and ileum of intact segments was observed than in duodenum and large intestine. These data indicate that colony-forming units of introduced bacteria remained greater in the small intestine after 6- and 12-h incubations; we have determined that a minimum of 2.0 × 105 cfu generates detection through these tissues (~1.0 to 21.0 relative light units/s). This study demonstrates the feasibility of using biophotonics in research models ex vivo for monitoring the pathogenicity of Salmonella in swine, in place of, or in conjunction with, traditional microbiological assessments and whether a greater level of sensitivity of detection and correlation to actual bacterial concentrations can be achieved.

Copyright © 2009. Copyright 2009 Journal of Animal Science