Journal
MICROBIOLOGY-SGM
Volume 163, Issue 10, Pages 1515-1524Publisher
MICROBIOLOGY SOC
DOI: 10.1099/mic.0.000525
Keywords
avian pathogenic Escherichia coli; EtrA; regulator; intracellular survival; virulence
Categories
Funding
- National Natural Science Foundation of China [31572523]
- National Key Research and Development Program of China [2016YFD0500800]
- Chinese Special Fund for Agro-scientific Research in the Public Interest [201303044]
- Shanghai Key Project on Agricultural Development through Science and Technology grant [2016HNG4-1]
Ask authors/readers for more resources
The Escherichia coli type III secretion system 2 (ETT2) is found in most E. coli strains, including pathogenic and commensal strains. Although many ETT2 gene clusters carry multiple genetic mutations or deletions, ETT2 is known to be involved in bacterial virulence. In enterohaemorrhagic E. coli (EHEC), ETT2 affects adhesion through the regulator EtrA, which regulates transcription and secretion of the type III secretion system (T3SS) encoded by the locus of enterocyte effacement (LEE). To date, no studies have been conducted on the role of EtrA in the virulence of avian pathogenic E. coli (APEC), which harbours only ETT2. Thus, we constructed etrA mutant and complemented strains of APEC and evaluated their phenotypes and pathogenicities. We found that the etrA gene deletion significantly reduced bacterial survival in macrophages, and proliferation and virulence in ducks. In addition, the etrA gene deletion reduced expression of the APEC fimbriae genes. Upregulation of genes encoding the pro-inflammatory cytokines interleukin (IL)-1 beta and IL-8 was also observed in HD-11 macrophages infected with the etrA gene mutant strain compared to the wild-type strain. Furthermore, the altered capacities of the mutant strain were restored by genetic complementation. Our observations demonstrate that the ETT2 regulator EtrA contributes to the virulence of APEC.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available