益生菌Lactobacillus amylovorus S1对仔猪后肠菌群的影响

结合PCR/DGGE(Denaturinggradientgelelectrophoresis,变性梯度凝胶电泳)和16SrDNA序列分析技术,研究添加益生菌LactobacillusamylovorusS1后仔猪从7至35日龄(断奶后两周)后肠菌群的变化。6窝新生仔猪被随机分成两组:对照组和处理组,处理组仔猪于7、9和11日龄口服L.amylovorusS1菌液(活菌数5×109CFU/mL)。分别于7、14、21、24和35日龄,每窝随机屠宰一头仔猪,收集肠道样品。比较不同日龄仔猪后肠菌群DGGE图谱表明,断奶后图谱中多数高GC含量细菌条带消失,至断奶后两周又逐渐出现。序列分析显示,这些高GC含量细菌主要为乳酸杆菌。统计分析表明,仔猪口服益生菌S1对其盲肠和结肠菌群的多样性指数无显著影响。通过比较处理组和对照组图谱发现,处理组14日龄出现一特异条带,与其匹配的序列的最相似已知菌为Clostridiumdisporicum,相似性为95%;而35日龄对照组有一特异优势条带,该条带被鉴定为猪链球菌(Streptococcussuis),相似性为99%。

Changes of bacterial flora from hindguts of piglets after oral administration of Lactobacillus amylovorus S1 as a probiotic strain

Changes of bacterial flora from hindguts of piglets from 7 to 35 days of age (two weeks after weaning) were studied after oral administration of L. amylovorus S1, using molecular techniques based on 16S rDNA gene. Six litters of neonatal piglets were divided randomly into control group and treatment group. At 7, 9, 11 days of age, piglets in treatment group received 1, 2 and 3mL preparation of S1 (5 x 10(9) CFU/mL) through oral administration, respectively. On D 7, 14, 21, 24 and 35, one piglet from each litter was slaughtered and samples of hindguts were collected for analysis. The results showed that high G + C mol% bacteria in hindguts of piglets disappeared after weaning and restored gradually two weeks later. Sequencing analysis indicated that most of these high G + C mol% bacteria blonged to Lactobacillus spp. . Statistical analysis showed that treatment with S1 had no marked effect on diversity index of predominant bacteria from hindguts in piglets. By comparing the bands in DGGE profiles between two groups, a specific band in treatment group was found in profiles from piglets at 14 days of age, sequence matched with that showed 95 % similarity to Clostridium disporicum. At 35 days of age, another specific band appeared in control group, which was identified to be Streptococcus suis (99% ).