The gfc operon is involved in the formation of the O antigen capsule in Aeromonas hydrophila and contributes to virulence in channel catfish
Aquaculture(2019)
Abstract
A hypervirulent A. hydrophila (vAh) pathotype has been identified as the etiologic agent involved in disease outbreaks in farmed carp and catfish species in China and the Southeastern United States, respectively. To assess the role of the LPS O-antigen in vAh virulence, the O-antigen ligase (waaL) and O-antigen polymerase (wzy) genes were deleted. While neither waaL nor wzy were found to be required for vAh virulence, a waaL mutant was found to have a polar effect on an adjacent group 4 capsule (gfc) genetic operon that was predicted to play a role in capsule assembly. Mutations in the gfc operon attenuated vAh virulence in channel catfish, particularly the mutant lacking gfcD that is predicted to encode an outer membrane protein required for capsular polysaccharide export. Furthermore, the vAh gfcD mutant was found to lack significant biofilm-forming capacity or buoyancy compared to wild-type vAh and induced an adaptive immune response that protected catfish from vAh challenge. This study indicates the importance of the capsular polysaccharide assembly process in the pathogenesis of this highly virulent A. hydrophila pathotype.
MoreTranslated text
Key words
Aeromonas hydrophila,Pathogenesis,O-antigen,Capsule,Fish,LPS
AI Read Science
Must-Reading Tree
Example
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined