Infection Heterogeneity and Microbiota Differences in Chicks Infected by <i>Salmonella enteritidis</i>

• Main Authors: Shu Wu, Guanglei Cong, Qianyun Zhang, Hong Yao, Zhenxin Wang, Kelang Kang, Xi He, Shourong Shi
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Microorganisms
• Subjects: <i>Salmonella enteritidis</i>; heterogeneity; cecal microbiome; intestinal barrier; <i>Desulfovibrio_piger</i>
• Online Access: https://www.mdpi.com/2076-2607/9/8/1705

This study was conducted to compare the infection heterogeneity and cecal microbiota in chicks infected by <i>S. enteritidis</i>. Forty-eight 8-d-old female Arbor Acres chicks were challenged with <i>S. enteritidis</i> and euthanized 24 h later. The eight chicks with the highest <i>Salmonella</i> tissue loads were assigned to group S (<i>S. enteritidis</i>-susceptible), and the eight chicks with the lowest <i>Salmonella</i> tissue loads were assigned to group R (<i>S. enteritidis</i>-resistant). Chicks in group S showed a higher liver index (<i>p</i> < 0.05), obvious liver lesions, and an decreasing trend for the villus height-to-crypt depth ratio (<i>p</i> < 0.10), compared with those in group R. Gene expression of <i>occludin</i>, <i>MUC2</i>, and <i>IL10</i> was higher, whereas that of <i>iNOS</i> and <i>IL6</i> was lower (<i>p</i> < 0.05), in chicks of group R relative to those in group S. Separation of the cecal microbial community structure has been found between the two groups. The <i>S. enteritidis</i>-susceptible chicks showed higher abundance of pathogenic bacteria (<i>Fusobacterium</i> and <i>Helicobacter</i>) in their cecal, while <i>Desulfovibrio_piger</i> was enriched in the cecal of <i>S. enteritidis</i>-resistant chicks. In summary, chicks showed heterogeneous responses to <i>S. enteritidis</i> infection. Enhanced intestinal barrier function and cecal microbiota structure, especially a higher abundance of <i>Desulfovibrio_piger</i>, may help chicks resist <i>S. enteritidis</i> invasion.