Histological and Comparative Transcriptome Analyses Provide Insights into Small Intestine Health in Diarrheal Piglets after Infection with Clostridium Perfringens Type C.

Simple Summary Clostridium perfringens (C. perfringens), formerly called Clostridium welchii, is a spore-forming pathogenic bacterium. C. perfringens type C can produce fatal toxins, which are absorbed by the small intestine into the body causing diarrhea in humans and animals, especially piglets. Each year, diarrhea induced by this pathogen causes significant economic loss to the pig industry worldwide. Nevertheless, the regulatory mechanisms of the duodenum, jejunum, and ileum in piglets challenged by C. perfringens type C are poorly understood. This study aimed to identify pathological changes and genes associated with the small intestine in piglets after infection with C. perfringens type C. RNA-Sequencing (RNA-Seq), enzyme-linked immunosorbent assay (ELISA), and hematoxylin & eosin (H&E) staining were used to analyze duodenal, jejunal, and ileal tissues. Our results showed that treated piglets were successfully infected with C. perfringens type C. These findings will help to elucidate the pathogenicity of piglets infected with this pathogen. Abstract C. perfringens type C can induce enteritis accompanied by diarrhea and annually causes significant economic losses to the global pig industry. The pathogenic mechanisms of C. perfringens type C in pigs are still largely unknown. To investigate this, we challenged seven-day-old piglets with C. perfringens type C to cause diarrhea. We performed hematoxylin & eosin (H&E) staining of the small intestine (including duodenum, jejunum, and ileum) and assessed gene expression in the ileal tissue. H&E staining of the duodenum, jejunum, and ileum demonstrated inflammation and edema of the lamina propria and submucosa. A total of 2181 differentially expressed genes (DEGs) were obtained in ileal tissues. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis of DEGs indicated that the main pathways were enriched in the T cell receptor signaling pathway, NF-kappa B signaling pathway, and (tumor necrosis factor) TNF signaling pathway. These results provide insights into the pathogenicity of C. perfringens type C and improve our understanding of host-bacteria interactions.