YqeH contributes to avian pathogenic Escherichia coli pathogenicity by regulating motility, biofilm formation, and virulence

AbstractAvian pathogenicEscherichia coli (APEC) is a pathotype of extraintestinal pathogenicE. coli and one of the most serious infectious diseases of poultry. It not only causes great economic losses to the poultry industry, but also poses a serious threat to public health worldwide. Here, we examined the role of YqeH, a transcriptional regulator located atE. coli type III secretion system 2 (ETT2), in APEC pathogenesis. To investigate the effects of YqeH on APEC phenotype and virulence, we constructed ayqeH deletion mutant (APEC40- ΔyqeH) and a complemented strain (APEC40-C ΔyqeH) of APEC40. Compared with the wild type (WT), the motility and biofilm formation of APEC40- ΔyqeH were significantly reduced. TheyqeH mutant was highly attenuated in a chick infection model compared with WT, and showed severe defects in its adherence to and invasion of chicken embryo fibroblast DF-1 cells. However, the mechanisms underlying these phenomena were unclear. Therefore, we analyzed the transcriptional effects of theyqeH deletion to clarify the regulatory mechanisms of YqeH, and the role of YqeH in APEC virulence. The deletion ofyqeH downregulated the transcript levels of several flagellum-, biofilm-, and virulence-related genes. Our results demonstrate that YqeH is involved in APEC pathogenesis, and the reduced virulence of APEC40- ΔyqeH may be related to its reduced motility and biofilm formation.
Source: Veterinary Research - Category: Veterinary Research Source Type: research