title: Autoinducer-2 of quorum sensing is involved in cell damage caused by avian pathogenic Escherichia coli.
abstract: Avian pathogenic Escherichia coli (APEC) infections are responsible for great losses in the poultry industry. Quorum sensing (QS) acts as a global regulatory system that controls genes involved in bacterial pathogenesis, metabolism and protein biosynthesis. However, whether QS of APEC is related to cell damage has not been elucidated. In the present study, we explored the correlation between the damage of chicken type II pneumocytes induced by APEC and the autoinducer-2 (AI-2) activity of APEC. The results showed that when chicken type II pneumocytes were co-cultured with 108CFU/ml of APEC-O78 for 6 h, the release of LDH reached the highest level (192.5 ± 13.4 U/L) (P < 0.01), and the percentages of dead cells followed the same trend in trypan blue exclusion assay. In addition, the AI-2 activity of cell-free culture fluid (CF) reached the maximum value after 6 h co-culture with 108CFU/ml of APEC-O78. At the same time, the mRNA expressions of eight virulence genes (papC, fimA, fimC, hlyE, ompA, luxS, pfs, and qseA) of 108CFU/ml APEC-O78 were significantly increased compared with those of 107CFU/ml, and the mRNA expressions of four virulence genes (hlyE, tsh, iss, and luxS) of 108CFU/ml APEC-O78 were higher than those of 109CFU/ml (p < 0.05) after incubation for 6 h. These results suggested that AI-2-mediated QS is involved in the cell damage induced by APEC-O78, indicating AI-2 may be one new potential target for preventing chicken colibacillosis.
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China.
authors: Zhen-Qiang
authors: ZQ
authors: Cui
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China.
authors: Zong-Mei
authors: ZM
authors: Wu
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China.
authors: Yun-Xing
authors: YX
authors: Fu
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China.
authors: Dao-Xiu
authors: DX
authors: Xu
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China.
authors: Xun
authors: X
authors: Guo
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China.
authors: Hai-Qing
authors: HQ
authors: Shen
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China.
authors: Xu-Bin
authors: XB
authors: Wei
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China.
authors: Peng-Fei
authors: PF
authors: Yi
authors: Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Jilin University, No. 5333 Xi'an Road, Changchun, Jilin 130062, China. Electronic address: fubd@jlu.edu.cn.
authors: Ben-Dong
authors: BD
authors: Fu
mesh_terms: D056809:Alveolar Epithelial Cells / Q000382:microbiology* / Q000502:physiology*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002645:Chickens; D018920:Coculture Techniques; D004926:Escherichia coli / Q000472:pathogenicity* / Q000502:physiology; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D007783:Lactones / Q000378:metabolism*; D053038:Quorum Sensing; D013194:Staining and Labeling; D014343:Trypan Blue / Q000032:analysis; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D007783:Lactones; C091088:N-octanoylhomoserine lactone; D037521:Virulence Factors; D006714:Homoserine; D007770:L-Lactate Dehydrogenase; D014343:Trypan Blue
keywords: Autoinducer-2; Avian pathogenic Escherichia coli; Cell damage; Chicken type II pneumocyte; Quorum sensing