Warneboldt Franziska, Sander Saara J, Beineke Andreas, Valentin-Weigand Peter, Kamphues Josef, Baums Christoph Georg
Institute for Animal Nutrition, University of Veterinary Medicine Hannover, 30173 Hannover, Germany.
Department of Pathology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany.
Pathogens. 2016 Aug 6;5(3):56. doi: 10.3390/pathogens5030056.
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.
猪链球菌经肠道内接种后可穿过仔猪的肠道屏障。基于这些发现，有人提出了一种经口-胃肠道的感染途径。因此，本研究的目的是调查猪链球菌在猪胃中的存活情况。由于投喂细颗粒饲料，胃内容物的pH值相对较高，为5，猪链球菌2型和9型在其中孵育60分钟后未检测到存活细菌，而在这些条件下，德比沙门氏菌的数量增加。进一步的实验证实，在pH值为4.7的胃内容物中，猪链球菌2型和9型在30分钟内被清除，与细菌生长阶段无关。最后，进行了一项口服感染实验，给18头仔猪分别喂食混有10(10)CFU猪链球菌2型或9型的日粮。在不同暴露时间后，对各种肠系膜-肠道淋巴结和内脏进行全面的细菌学筛查，未检测到口服接种的攻击菌株。总之，猪胃构成了抵御经口-胃肠道猪链球菌感染的非常有效的屏障。导致猪链球菌通过胃的条件仍有待确定。
