Calpis America, Inc., Peachtree City, GA 30269, USA.
Calpis America, Inc., Peachtree City, GA 30269, USA.
Poult Sci. 2021 Oct;100(10):101385. doi: 10.1016/j.psj.2021.101385. Epub 2021 Jul 14.
Salmonella enterica serovar Enteritidis (SE) has consistently been the most common serotype associated with the foodborne Salmonellosis worldwide. In this study, the effect of a dietary direct-fed microbial (DFM) and yeast cell walls (YCW) under a challenge of nalidixic acid resistant SE strain using layer chicks has been investigated. A total of 160 newly hatched Dekalb White female chicks were randomly assigned into 2 experimental groups (80 birds/treatment), control group (CON) and treatment group (DY). Chicks were fed ad libitum a non-medicated-corn-soy based diet and DY was supplemented with the combination of DFM and YCW. At 8 days of age, 2.1 × 10 CFU/bird of the SE was given to all chicks by oral administration. On 3 days postinoculation (dpi), 20 chicks/group were euthanized and all cecal contents were collected for analysis. On 6, 10, and 14 dpi, the cecal contents were sampled from 16 chicks per group. The number of SE in the cecal contents was counted using culture-based methods. A 16S rRNA-based microbiota analysis was performed for additional microbial profiling. The CON and DY showed difference (P ≤ 0.05) in β diversity throughout the trial. Prevalence of SE in cecal contents was lower (P ≤ 0.05) in DY across all time-points. Lower abundance of Salmonella spp. was also shown in DY by liner discriminant analysis effect size (LEfSe). DY increased (P ≤ 0.05) diversity of bacterial species in the cecal contents in DY at 10 and 14 dpi. For the SE challenged birds, SE reduction in DY was observed at 3 dpi and until the end of the trial at 14 dpi confirming a numerically larger difference between groups as well as an increase in bacterial species diversity in DY. It could be hypothesized that the SE reduction shown immediately after the challenge and the greater SE reduction shown after 10 dpi may be the synergistic effect of the combined feed additives.
肠炎沙门氏菌血清型肠炎（SE）一直是全球与食源性沙门氏菌病相关的最常见血清型。本研究采用蛋鸡研究了日粮中直接饲喂微生物（DFM）和酵母细胞壁（YCW）在耐萘啶酸 SE 菌株挑战下的影响。将 160 只新孵化的 Dekalb White 雌性小鸡随机分配到 2 个实验组（每组 80 只鸟），对照组（CON）和处理组（DY）。小鸡自由采食无药玉米 - 大豆基础日粮，DY 补充 DFM 和 YCW 的组合。在 8 日龄时，通过口服给予所有小鸡 2.1×10 CFU/鸡的 SE。接种后 3 天（dpi），每组处死 20 只小鸡，收集所有盲肠内容物进行分析。在 6、10 和 14 dpi，从每组 16 只小鸡中取样盲肠内容物。通过基于培养的方法计数盲肠内容物中的 SE 数量。进行 16S rRNA 基于微生物组分析以进行额外的微生物分析。在整个试验过程中，CON 和 DY 的 β多样性存在差异（P≤0.05）。在所有时间点，DY 中盲肠内容物中 SE 的流行率较低（P≤0.05）。线性判别分析效应大小（LEfSe）也显示 DY 中沙门氏菌属的丰度较低。在 10 和 14 dpi，DY 增加了盲肠内容物中细菌种类的多样性（P≤0.05）。对于 SE 挑战的鸟类，在 3 dpi 时观察到 DY 中的 SE 减少，并持续到 14 dpi 的试验结束，这证实了两组之间的差异更大，并且 DY 中的细菌种类多样性增加。可以假设，在挑战后立即显示的 SE 减少以及在 10 dpi 后显示的更大 SE 减少可能是联合饲料添加剂的协同作用。
