AUTHOR=Liu Jin , Wu Shuangqi , Zhao Honghao , Ye Chun , Fu Shulin , Liu Yu , Liu Ting , Qiu Yinsheng 

TITLE=Baicalin-aluminum alleviates necrotic enteritis in broiler chickens by inhibiting virulence factors expression of Clostridium perfringens

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1243819

DOI=10.3389/fcimb.2023.1243819

ISSN=2235-2988

ABSTRACT=<p><italic>Clostridium perfringens</italic> type A is the main cause of necrotic enteritis (NE) in chickens. Since the use of antibiotics in feed is withdrawn, it is imperative to find out suitable alternatives to control NE. Baicalin-aluminum complex is synthesized from baicalin, a flavonoid isolated from <italic>Scutellaria baicalensis</italic> Georgi. The present study investigated the effects of baicalin-aluminum on the virulence-associated traits and virulence genes expression of <italic>C. perfringens</italic> CVCC2030, it also evaluated the <italic>in vivo</italic> therapeutic effect on NE. The results showed that baicalin-aluminum inhibited bacterial hemolytic activity, diminished biofilm formation, attenuated cytotoxicity to Caco-2 cells, downregulated the expression of genes encoding for clostridial toxins and extracellular enzymes such as alpha toxin (CPA), perfringolysin O (PFO), collagenase (ColA), and sialidases (NanI, NanJ). Additionally, baicalin-aluminum was found to negatively regulate the expression of genes involved in quorum sensing (QS) communication, including genes of Agr QS system (<italic>agrB</italic>, <italic>agrD</italic>) and genes of VirS/R two-component regulatory system (<italic>virS</italic>, <italic>virR</italic>). <italic>In vivo</italic> experiments, baicalin-aluminum lightened the intestinal lesions and histological damage, it inhibited pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) expression in the jejunal and ileal tissues. Besides, baicalin-aluminum alleviated the upregulation of <italic>C. perfringens</italic> and <italic>Escherichia coli</italic> and raised the relative abundance of <italic>Lactobacillus</italic> in the ileal digesta. This study suggests that baicalin-aluminum may be a potential candidate against <italic>C. perfringens</italic> infection by inhibiting the virulence-associated traits and virulence genes expression.</p>