title: Comparative proteomic analysis of the membrane proteins of two Haemophilus parasuis strains to identify proteins that may help in habitat adaptation and pathogenesis.
abstract: BACKGROUND
  Haemophilus parasuis is the causative agent of Glässer's disease characterized by polyserositis, arthritis, and meningitis in pig, leading to serious economic loss. Despite many years of study, virulence factors and the mechanisms of the entire infection process remain largely unclear. So two-dimensional gel electrophoresis and mass spectrometry were used to search for distinctions at the membrane protein expression level between two H. parasuis isolates aimed at uncovering some proteins potentially involved in habitat adaption and pathogenesis.
  
  
  RESULTS
  A comparative proteomic approach combining two-dimensional gel electrophoresis with mass spectrometry and tandem mass spectrometry was employed to explore the differences among membrane proteomes of a virulent Haemophilus parasuis strain isolated from the lung of a diseased pig and an avirulent strain isolated from the nasal swab of a healthy pig. Differentially expressed protein spots identified by mass spectrometry were annotated and analyzed by bioinformatic interpretation. The mRNA level was determined by quantitative real-time PCR. Proteins representing diverse functional activities were identified. Among them, the tonB-dependent siderophore receptor was a new discovery highlighted for its activity in iron uptake. In addition, periplasmic serine protease and putrescine/spermidine ABC transporter substrate-binding protein were given focus because of their virulence potential. This study revealed that the differentially expressed proteins were important in either the habitat adaption or pathogenesis of H. parasuis.
  
  
  CONCLUSIONS
  The outcome demonstrated the presence of some proteins which raise the speculation for their importance in helping in habitat adaption or pathogenesis within the host.
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Luhua
authors: L
authors: Zhang
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Yiping
authors: Y
authors: Wen
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Ying
authors: Y
authors: Li
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Xingliang
authors: X
authors: Wei
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Xuefeng
authors: X
authors: Yan
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Xintian
authors: X
authors: Wen
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Rui
authors: R
authors: Wu
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Xiaobo
authors: X
authors: Huang
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Yong
authors: Y
authors: Huang
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Qigui
authors: Q
authors: Yan
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Mafeng
authors: M
authors: Liu
authors: Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan 625014, PR China.
authors: Sanjie
authors: S
authors: Cao
keywords: Comparative proteomics; Habitat adaption; Haemophilus parasuis; Pathogenesis