Su Yong, Yao Wen, Perez-Gutierrez Odette N, Smidt Hauke, Zhu Wei-Yun
Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
FEMS Microbiol Ecol. 2008 Dec;66(3):546-55. doi: 10.1111/j.1574-6941.2008.00529.x. Epub 2008 Jun 12.
This present study investigated the changes in bacterial community composition, with an emphasis on Lactobacillus spp. and Streptococcus suis populations as potentially beneficial and harmful groups, in the stomach, jejunum and ileum of piglets after weaning (21 days postpartum) by 16S rRNA gene-based methods. Denaturing gradient gel electrophoresis analysis showed that, after weaning, predominant bands related to Lactobacillus spp. disappeared and were replaced by potential pathogenic species, such as Peptostreptococcus anaerobius, Moraxella cuniculi, S. suis and Porphyromonas catoniae. Real-time PCR revealed that the abundances of lactobacilli and Lactobacillus sobrius as a proportion of total bacterial abundance were significantly lower in the stomach, jejunum and ileum of weaned piglets than in 21-day-old piglets. A specific and sensitive real-time PCR assay was developed for quantification of the important pathogen S. suis within gastrointestinal microbiota. The assay showed that S. suis predominated in the stomach samples of weaned piglets with population levels up to 10(7) copies g(-1) digesta, while it was not detected in the stomach before weaning. Streptococcus suis was not dominant in the jejunum and ileum digesta before weaning, but became dominant after weaning, with population levels up to 10(7) copies g(-1) digesta. The results demonstrated for the first time the postweaning dominance of the potentially harmful S. suis in piglet intestine. The results also suggest that the defensive barrier of the stomach can be impaired as S. suis became dominant while the proportion of Lactobacillus populations decreased after weaning, which may further result in an increase of S. suis abundance in the intestine.
本研究采用基于16S rRNA基因的方法，调查了断奶（产后21天）仔猪胃、空肠和回肠中细菌群落组成的变化，重点关注乳酸杆菌属和猪链球菌种群，分别作为潜在有益菌和有害菌群体。变性梯度凝胶电泳分析表明，断奶后，与乳酸杆菌属相关的主要条带消失，并被潜在病原菌所取代，如厌氧消化链球菌、兔莫拉菌、猪链球菌和卡托尼亚卟啉单胞菌。实时PCR显示，断奶仔猪胃、空肠和回肠中乳酸杆菌和嗜酒乳酸杆菌占总细菌丰度的比例显著低于21日龄仔猪。开发了一种特异性和灵敏的实时PCR检测方法，用于定量胃肠道微生物群中的重要病原菌猪链球菌。该检测方法表明，猪链球菌在断奶仔猪胃样本中占主导地位，种群水平高达10(7)拷贝g(-1)食糜，而在断奶前的胃中未检测到。断奶前猪链球菌在空肠和回肠食糜中不占优势，但断奶后成为优势菌，种群水平高达10(7)拷贝g(-1)食糜。结果首次证明了断奶后潜在有害菌猪链球菌在仔猪肠道中的优势地位。结果还表明，断奶后随着猪链球菌占主导地位且乳酸杆菌种群比例下降，胃的防御屏障可能受损，这可能进一步导致肠道中猪链球菌丰度增加。
