The Food Safety Research of Animal Origin team of SHVRI, CAAS has recently revealed the role of fdhD in the pathogenicity and its regulatory characteristics in avian pathogenic Escherichia coli. The related work has been reported in Veterinary Microbiology.
Background
Avian Pathogenic Escherichia coli(APEC) is a significant cause of severe respiratory and systemic infections in poultry, resulting in substantial economic losses. This research investigates a critical bacterial gene,fdhD, to understand its role in APEC's virulence. The fdhD gene enables APEC to thrive in low-oxygen conditions by metabolizing formate for energy, which promotes adaptation and may contribute to antimicrobial resistance. This study aims to elucidate how fdhD influences key infection mechanisms like bacterial motility, serum resistance, and biofilm formation. By understanding these fundamental processes, our research seeks to identify novel targets for controlling APEC infections, which is increasingly critical due to the challenges of antibiotic resistance and the potential zoonotic threat APEC poses.
Progress
In this study on APEC, a bacterium causing severe economic losses in poultry. FdhD was identified that interacted with the quorum-sensing regulator LsrR to control virulence. Research on clinically isolated strains revealed high antibiotic resistance and found that deleting fdhD gene significantly impaired the bacteria's ability to form biofilms, move, survive in serum, adhere to host cells, and cause lethal infection in animal models. Molecular analysis confirmed LsrR binds directly to these genes' promoters, and their deletion downregulated critical virulence factors like flagella and fimbriae while also dampening the host's inflammatory immune response. This work establishes fdhD as crucial regulators of APEC pathogenicity, highlighting it as promising new targets for developing strategies to control this costly poultry disease.
fdhD mediates quorum-sensing control of APEC virulence
Funding
PhD graduate student Saqib Nawaz was the first author of the this article. Professor Jiang Wei and Professor Xaingan Han from SHVRI, CAAS, were the co-corresponding authors. This research project was financially supported by the National Natural Science Foundation of China (Grant No. U22A20518, 32072829, 32302883) and the Shanghai Natural Science Foundation of China (Grant No. 22ZR1475800).
Original link
https://doi.org/10.1016/j.vetmic.2025.110560
