title: Clearance of Streptococcus suis in Stomach Contents of Differently Fed Growing Pigs.
abstract: Streptococcus (S.) suis translocates across the intestinal barrier of piglets after intraintestinal application. Based on these findings, an oro-gastrointestinal infection route has been proposed. Thus, the objective of this study was to investigate the survival of S. suis in the porcine stomach. Whereas surviving bacteria of S. suis serotypes 2 and 9 were not detectable after 60 min of incubation in stomach contents with a comparatively high gastric pH of 5 due to feeding of fine pellets, the number of Salmonella Derby bacteria increased under these conditions. Further experiments confirmed the clearance of S. suis serotypes 2 and 9 within 30 min in stomach contents with a pH of 4.7 independently of the bacterial growth phase. Finally, an oral infection experiment was conducted, feeding each of 18 piglets a diet mixed with 10(10) CFU of S. suis serotype 2 or 9. Thorough bacteriological screenings of various mesenteric-intestinal lymph nodes and internal organs after different times of exposure did not lead to any detection of the orally applied challenge strains. In conclusion, the porcine stomach constitutes a very efficient barrier against oro-gastrointenstinal S. suis infections. Conditions leading to the passage of S. suis through the stomach remain to be identified.
authors: Institute for Animal Nutrition, University of Veterinary Medicine Hannover, 30173 Hannover, Germany. Franziska.Koop@googlemail.com.
authors: Franziska
authors: F
authors: Warneboldt
authors: Institute for Animal Nutrition, University of Veterinary Medicine Hannover, 30173 Hannover, Germany. saara.sander@tiho-hannover.de.
authors: Saara J
authors: SJ
authors: Sander
authors: Department of Pathology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany. andreas.beineke@tiho-hannover.de.
authors: Andreas
authors: A
authors: Beineke
authors: Institute for Microbiology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany. peter.valentin@tiho-hannover.de.
authors: Peter
authors: P
authors: Valentin-Weigand
authors: Institute for Animal Nutrition, University of Veterinary Medicine Hannover, 30173 Hannover, Germany. josef.kamphues@tiho-hannover.de.
authors: Josef
authors: J
authors: Kamphues
authors: Institute for Microbiology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany. christoph.baums@vetmed.uni-leipzig.de.|Institute for Bacteriology and Mycology, Centre of Infectious Diseases, College of Veterinary Medicine, University Leipzig, 04103 Leipzig, Germany. christoph.baums@vetmed.uni-leipzig.de.
authors: Christoph Georg
authors: CG
authors: Baums
keywords: Streptococcus suis; oro-gastrointestinal infection; pig; stomach content