Anti-bacterial activity of baicalin against APEC through inhibition of quorum sensing and inflammatory responses

• Published in: Scientific reports Vol. 9; no. 1; p. 4063
• Main Authors: Peng, Lu-Yuan, Yuan, Meng, Wu, Zong-Mei, Song, Ke, Zhang, Chun-Lei, An, Qiang, Xia, Fang, Yu, Jia-Lin, Yi, Peng-Fei, Fu, Ben-Dong, Shen, Hai-Qing
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11-03-2019; Nature Publishing Group
• Subjects: 13/21; 631/326/41/88; 692/699; 82; 82/51; Animals; Anti-Bacterial Agents - pharmacology; Baicalin; Biofilms; Biofilms - drug effects; Chickens; Colibacillosis; Cytokines; DNA-Binding Proteins - genetics; E coli; Escherichia coli - drug effects; Escherichia coli - pathogenicity; Escherichia coli Infections - microbiology; Escherichia coli Infections - prevention & control; Escherichia coli Proteins - drug effects; Escherichia coli Proteins - genetics; Flavonoids - pharmacology; Gene Expression Regulation, Bacterial - drug effects; Humanities and Social Sciences; Inflammation; Integrases - genetics; L-Lactate dehydrogenase; Lactic acid; LuxS protein; Morbidity; multidisciplinary; NF-κB protein; Pathogenicity; Pathogens; Pneumocytes; Poultry - genetics; Poultry Diseases - drug therapy; Poultry Diseases - microbiology; Quorum sensing; Quorum Sensing - drug effects; Quorum Sensing - genetics; Science; Science (multidisciplinary); Virulence factors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-40684-6

Avian pathogenic
Escherichia coli
(APEC), collectively known as causative agent of extraintestinal infections, is an important cause of morbidity and mortality in poultry. Currently, quorum sensing (QS), biofilm formation and virulence factors are considered as novel prospective targets for antimicrobial therapy to control APEC invasion. In addition, inflammatory responses are also served as the major pathological features of APEC invasion. This study was aimed to explore the effect of baicalin on APEC and APEC-induced inflammatory responses. After treatment with baicalin, we mainly examined the AI-2 secretion, biofilm formation, expression of virulence genes of APEC, and the levels of inflammatory cytokines, as well as the expression of NF-κB pathway. Our results showed that baicalin significantly inhibited the QS via decreasing the AI-2 secretion, biofilm formation, and the expression of virulence genes of APEC such as
LsrB, LsrK, LuxS, pfs, H-NS, fimA, fimB, fyuA, csgA, csgB
, and
rpoS
. Moreover, baicalin significantly attenuated the release of lactate dehydrogenase (LDH), and the adhesion of APEC to chicken type II pneumocytes to reduce cell damage. Furthermore, baicalin also inhibited the expression of pro-inflammatory cytokines and NF-κB activation. Thus, our data revealed that baicalin could interfere with the quorum sensing, biofilm formation and virulence genes expression to relieve the APEC pathogenicity. Additionally, baicalin decreased the inflammatory responses of chicken type II pneumocytes induced by APEC. Taken together, these data provide a novel potential pharmaco-therapeutic approach to chicken colibacillosis.