Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China.
Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China.
Microb Pathog. 2018 Sep;122:174-179. doi: 10.1016/j.micpath.2018.06.022. Epub 2018 Jun 12.
The aim study was to explore the distribution of Salmonella Enteritidis (S. enteritidis) in internal organs and variation of cecum microbiota in newly hatched chicken after oral challenge during a 21-day period. The quantities of S. enteritidis DNA in different internal organs (heart, liver, spleen, stomach, pancreas, small intestine, blood and cecum contents) were determined by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR). The result showed that all of the above-mentioned samples were positive at 12 h post inoculation (PI) after oral challenge. The highest copy numbers of S. enteritidis in all tissue were heart and liver, with about 2 × 10 to 6 × 10 copies of DNA target sequences/0.5 g. The copy number of S. enteritidis in the stomach was only lower than the heart and liver. The blood at 8 d PI, the pancreas at 10 d PI, the heart at 14 d PI and the stomach at 17 d PI didn't have a positive result. However, the liver, spleen, cecum contents and small intestine were all positive during the 21-day period. The cecum contents at 0 d PI, 4 d PI and 10 d PI from the control group and experiment group were collected for bacterial 16 S rRNA sequencing targeting the V3-V4 hypervariable region. The result showed that at the 0 d PI, the main cecum microbiota ingredient of the two-day old chicken was Enterobacteriaceae (Proteobacteria) and the other microbiology species were fewer. At the 10 d PI, the microbiota ingredient of cecum became abundant and stable mainly including the families Ruminococcaceae (Firmicutes), Enterobacteriaceae (Proteobacteria), Lachnospiraceae (Firmicutes) and clostridiacaea (Firmicutes) both of the two group, suggesting Salmonella infection with 2-day old chicken might not significantly change cecum microbiota community. The study indicated the major organs, which carried numerous S. enteritidis, providing a significantly guideline for salmonella detection in poultry and revealed the main microbiota ingredient of chicken cecum.
本研究旨在探索经口感染后，21 天内刚孵化小鸡的盲肠微生物群的变化及肠炎沙门氏菌（S. enteritidis）在内部器官中的分布。通过实时荧光定量聚合酶链反应（FQ-PCR）检测不同内脏器官（心脏、肝脏、脾脏、胃、胰腺、小肠、血液和盲肠内容物）中 S. enteritidis DNA 的数量。结果显示，经口感染后 12 小时（PI）所有上述样本均为阳性。所有组织中 S. enteritidis 的最高拷贝数均为心脏和肝脏，约为 2×10 到 6×10 个 DNA 靶序列/0.5g。胃中的 S. enteritidis 拷贝数仅低于心脏和肝脏。8 d PI 时的血液、10 d PI 时的胰腺、14 d PI 时的心脏和 17 d PI 时的胃均未检测到阳性结果。然而，肝脏、脾脏、盲肠内容物和小肠在 21 天内均为阳性。对照组和实验组在 0 d PI、4 d PI 和 10 d PI 时采集盲肠内容物进行细菌 16S rRNA 测序，以靶向 V3-V4 高变区。结果表明，在 0 d PI 时，2 日龄雏鸡盲肠的主要微生物成分是肠杆菌科（变形菌门），其他微生物种类较少。在 10 d PI 时，盲肠微生物成分变得丰富且稳定，主要包括两个组的瘤胃球菌科（厚壁菌门）、肠杆菌科（变形菌门）、lachnospiraceae（厚壁菌门）和梭菌科（厚壁菌门），提示沙门氏菌感染 2 日龄小鸡不会显著改变盲肠微生物群落。该研究表明，携带大量 S. enteritidis 的主要器官为沙门氏菌检测提供了重要指导，并揭示了雏鸡盲肠的主要微生物成分。
