Abstract
Systemic infections by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide. IbeR, located on genomic island GimA, was shown to serve as an RpoS-like regulator in rpoS gene mutation neonatal meningitis E. coli (NMEC) RS218. However, the role of IbeR in pathogenicity of APEC carrying active RpoS has not yet been investigated. We showed that the APEC IbeR could elicit antibodies in infected ducks, suggesting that IbeR might be involved in APEC pathogenicity. To investigate the function of IbeR in APEC pathogenesis, mutant and complementation strains were constructed and characterized. Inactivation of ibeR led to attenuated virulence and reduced invasion capacity towards DF-1 cells, brains and cerebrospinal fluid (CSF) in vitro and in vivo. Bactericidal assays demonstrated that the mutant strain had impaired resistance to environmental stress and specific pathogen-free (SPF) chicken serum. These virulence-related phenotypes were restored by genetic complementation. Quantitative real-time reverse transcription PCR revealed that IbeR controlled expression of stress-resistance genes and virulence genes, which might led to the associated virulence phenotype.
Highlights
Extraintestinal pathogenic E. coli (ExPEC) strains have been implicated in a range of infections in humans and animals such as neonatal meningitis, urinary tract infections, pneumonia, and septicemia
ExPEC is currently categorized as newborn meningitis E. coli (NMEC), uropathogenic E. coli (UPEC), avian pathogenic E. coli (APEC), and septicemia-associated E. coli based on the original host and clinical symptoms [1,2,3,4]
These results indicated that IbeR was involved in invasion of the brain of APEC strain DE205B during systemic infection
Summary
Extraintestinal pathogenic E. coli (ExPEC) strains have been implicated in a range of infections in humans and animals such as neonatal meningitis, urinary tract infections, pneumonia, and septicemia. ExPEC is currently categorized as newborn meningitis E. coli (NMEC), uropathogenic E. coli (UPEC), avian pathogenic E. coli (APEC), and septicemia-associated E. coli based on the original host and clinical symptoms [1,2,3,4]. ExPEC possess a range of similar virulence factors such as the aerobactin iron transport system, Ibe proteins (IbeA, IbeB, IbeC), the K1 capsule, and types 1 and P fimbriae [3, 5,6,7,8,9,10]. Mounting evidence shows that poultry can be a PLOS ONE | DOI:10.1371/journal.pone.0119698. Mounting evidence shows that poultry can be a PLOS ONE | DOI:10.1371/journal.pone.0119698 March 13, 2015
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
