title: Role of outer membrane protein T in pathogenicity of avian pathogenic Escherichia coli.
abstract: An outer membrane protein T (OmpT) could play a vital role in the pathogenesis of the neonatal meningitis Escherichia coli (NMEC) in human and animals. However, whether ompT plays a role in avian pathogenic E. coli (APEC) infection remains unclear. In this study we evaluated the potential of ompT in APEC pathogenesis. An ompT gene was deleted from APEC mutant strain (TW-XM) was constructed and characterized. The inactivation of ompT reduced significantly the adherence and invasion capabilities of APEC to mouse brain microvascular endothelial cell (BMEC) bEnd.3 cells at the rates of 43.8% and 28.8% respectively, compared with the wild strain TW-XM. Further studies showed that deletion of ompT gene reduced the bacterial virulence with 15.2-fold in ducklings and 9.7-fold in mouse models based on the measurement of the LD50. Furthermore, experimental infection of animals revealed that, loss of ompT showed reduced APEC colonization and invasion capacity in brains, lungs and blood by 2-fold, 1.96-fold, and 1.7-fold, respectively, compared with the wild-type strain TW-XM. These virulence-related phenotypes were partially recoverable by genetic complementation. The results of the quantitative real-time reverse transcription-PCR (qRT-PCR) indicated that the loss of ompT significantly decreased the expression levels of ompA, fimC and tsh in the mutant strain ΔOmpT, when compared with TW-XM (p<0.01). Collectively, our data showed that inactivation of ompT decreased adhesion, invasion, colonization, proliferation capacities, possibly by reduced expression levels of ompA, fimC and tsh, which may justify that, ompT is implicated in APEC pathogenicity.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; College of Veterinary Sciences, University of Nyala, Nyala, Sudan.
authors.forename: Hassan M A
authors.initials: HMA
authors.lastname: Hejair
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Jiale
authors.initials: J
authors.lastname: Ma
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Yingchu
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Min
authors.initials: M
authors.lastname: Sun
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Wenyang
authors.initials: W
authors.lastname: Dong
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Zihao
authors.initials: Z
authors.lastname: Pan
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China. Electronic address: yaohch@njau.edu.cn.
authors.forename: Huochun
authors.initials: H
authors.lastname: Yao
mesh_terms: D000818:Animals; D004372:Ducks; D004926:Escherichia coli / Q000235:genetics*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics; D011201:Poultry Diseases / Q000382:microbiology; D060888:Real-Time Polymerase Chain Reaction; D017384:Sequence Deletion; D065288:Serogroup; D014774:Virulence / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D008565:Membrane Proteins
keywords: APEC; Adhesion; Invasion; Pathogenicity; ompT