Temporin-Derived Peptides Protect Mice against Enterohemorrhagic Escherichia coli O157:H7 Infection by Inhibiting Inflammation and Enhancing the Intestinal Epithelial Barrier.

Intestinal inflammation can destroy the integrity of the intestinal barrier and disrupt immune homeostasis, increasing the risks of developing fatal diseases. Enterohemorrhagic Escherichia coli (EHEC) O157:H7, a prominent pathogen primarily transmitted through contaminated food, is known to trigger intestinal inflammation and subsequent infections. Temporin-GHbK (GHbK) and temporin-GHb3K (GHb3K), derived from temporin-GHb of Hylarana guentheri, were synthesized and demonstrated antimicrobial and anti-biofilm activities against EHEC in vitro. They also exhibited efficacy in preventing EHEC infection in vivo. GHbK and GHb3K significantly decreased the disease activity index (DAI) in EHEC-infected mice in comparison with the untreated model group. The derived peptides exhibited barrier-protective effects by preserving structural integrity, reducing inflammatory infiltrates in the intestinal epithelium, and maintaining gut microbiota diversity. Taken together, GHbK and GHb3K exhibit promising anti-inflammatory and anti-infection potential against EHEC infection. These findings lay a foundation for exploring the application of antibacterial peptides in the treatment of EHEC infection.