title: Effects of quaternary benzo(c)phenanthridine alkaloids on growth performance, shedding of organisms, and gastrointestinal tract integrity in pigs inoculated with multidrug-resistant Salmonella spp.
abstract: OBJECTIVE
  To evaluate effects of quaternary benzo(c)phenanthridine alkaloids (QBAs) against Salmonella spp and determine effects on growth performance, organism shedding, and gastrointestinal tract integrity in pigs inoculated with Salmonella enterica serovar Typhimurium.
  
  
  METHODS
  36 Salmonella isolates and twenty 5-week-old pigs.
  
  
  METHODS
  Minimum inhibitory concentration of QBAs against the Salmonella isolates was determined. Pigs were allocated to 4 groups and inoculated with Salmonella organisms. Pigs received diets supplemented with 1.5 g of QBAs/1,000 kg of feed, 0.75 g of QBAs/1,000 kg of feed, or 59.4 g of chlortetracycline/1,000 kg of feed or a nonsupplemented (control) diet. Pigs were weighed on day 0 and then weekly for 40 days. Fecal samples were collected to quantify Salmonella organisms. Gastrointestinal tract integrity was evaluated by measuring transepithelial resistance.
  
  
  RESULTS
  In vitro, 9 of 36 (25%) Salmonella isolates were inhibited at 90 μg of QBAs/mL; all 36 were inhibited at 179 μg of QBAs/mL. Diets containing QBAs significantly decreased Salmonella spp shedding; shedding was lower 40 days after inoculation for pigs fed diets containing QBAs or chlortetracycline than for pigs fed the control diet. Growth performance was similar for pigs fed diets containing QBA or chlortetracycline. Gastrointestinal tract integrity was improved in pigs fed the diet containing 1.5 g of QBAs/1,000 kg of feed.
  
  
  CONCLUSIONS
  QBAs and chlortetracycline decreased Salmonella spp shedding but did not differ with regard to growth performance. Gastrointestinal tract integrity was better, albeit not significantly, in pigs fed diets containing QBAs. Further investigation into the role of QBAs and their mechanism as an immunomodulator is necessary.
authors.affiliation: Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27695.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Robbins
authors.forename: Valeria C
authors.initials: VC
authors.lastname: Artuso-Ponte
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Moeser
authors.forename: W E Morgan
authors.initials: WE
authors.lastname: Morrow
authors.forename: Jerry W
authors.initials: JW
authors.lastname: Spears
authors.forename: Wondwossen A
authors.initials: WA
authors.lastname: Gebreyes
mesh_terms: D000818:Animals; D057138:Bacterial Shedding / Q000187:drug effects; D053119:Benzophenanthridines / Q000494:pharmacology*; D002751:Chlortetracycline / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D005243:Feces / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000187:drug effects*; D048788:Growth and Development / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D012481:Salmonella Infections, Animal / Q000188:drug therapy*; D013552:Swine; D013553:Swine Diseases / Q000188:drug therapy* / Q000382:microbiology*
chemical_list: D053119:Benzophenanthridines; D002751:Chlortetracycline