title: HtrA Is Important for Stress Resistance and Virulence in Haemophilus parasuis.
abstract: Haemophilus parasuis is an opportunistic pathogen that causes Glässer's disease in swine, with polyserositis, meningitis, and arthritis. The high-temperature requirement A (HtrA)-like protease, which is involved in protein quality control, has been reported to be a virulence factor in many pathogens. In this study, we showed that HtrA of H. parasuis (HpHtrA) exhibited both chaperone and protease activities. Finally, nickel import ATP-binding protein (NikE), periplasmic dipeptide transport protein (DppA), and outer membrane protein A (OmpA) were identified as proteolytic substrates for HpHtrA. The protease activity reached its maximum at 40°C in a time-dependent manner. Disruption of the htrA gene from strain SC1401 affected tolerance to temperature stress and resistance to complement-mediated killing. Furthermore, increased autoagglutination and biofilm formation were detected in the htrA mutant. In addition, the htrA mutant was significantly attenuated in virulence in the murine model of infection. Together, these data demonstrate that HpHtrA plays an important role in the virulence of H. parasuis.
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
authors.forename: Luhua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Gee W
authors.initials: GW
authors.lastname: Lau
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Huang
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wu
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.|Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu, China.
authors.forename: Qigui
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Ma
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China xintian3211@126.com csanjie@sicau.edu.cn.
authors.forename: Xintian
authors.initials: X
authors.lastname: Wen
authors.affiliation: Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China xintian3211@126.com csanjie@sicau.edu.cn.|Sichuan Science-observation Experiment of Veterinary Drugs and Veterinary Biological Technology, Ministry of Agriculture, Chengdu, China.
authors.forename: Sanjie
authors.initials: S
authors.lastname: Cao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development; D003167:Complement Activation / Q000276:immunology; D004195:Disease Models, Animal; D005816:Genetic Complementation Test; D006192:Haemophilus Infections / Q000382:microbiology; D044137:Haemophilus parasuis / Q000502:physiology*; D051379:Mice; D018832:Molecular Chaperones; D009113:Muramidase / Q000378:metabolism; D009154:Mutation; D059748:Proteolysis; D011993:Recombinant Fusion Proteins; D013312:Stress, Physiological / Q000235:genetics*; D013379:Substrate Specificity; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D018832:Molecular Chaperones; D011993:Recombinant Fusion Proteins; D037521:Virulence Factors; D009113:Muramidase