title: Development of a Novel PmpD-N ELISA for Chlamydia psittaci Infection.
abstract: OBJECTIVE
  Chlamydia psittaci is an avian respiratory pathogen and zoonotic agent. The wide prevalence of C. psittaci poses a threat to the poultry industry and its employees. However, few commercial kits are available for detecting avian antibodies excluding the in-house ELISA kit. In this study, we developed a novel ELISA kit for detecting antibodies against C. psittaci based on the N-terminal fragment of polymorphic outer membrane protein D (PmpD-N) as the coating antigen.
  
  
  METHODS
  The antigen concentrations, primary antibody, and cut-off value were determined and optimized. The ELISA, designated PmpD-N ELISA, was assessed for sensitivity, specificity, and concordance using sera samples from 48 experimentally infected and 168 uninfected SPF chickens.
  
  
  RESULTS
  The sensitivity and specificity of PmpD-N ELISA were 97.9%, 100%, respectively, while the concordance was 98.1% as compared to that of MOMP-ELISA. No cross-reaction with positive sera for other avian pathogens was found. Using PmpD-N ELISA, 799/836 clinical samples were positive, including 93.0% and 98.1% positivity in layers and broilers, respectively.
  
  
  CONCLUSIONS
  These data indicate that indirect ELISA with PmpD-N as the antigen candidate is a promising approach for the surveillance of C. psittaci infection.
authors.affiliation: Key Lab of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Tongren Polytechnic College, Tongren 554300, Guizhou, China; National and Local Engineering Research Centre for Separation and Purification Ethnic Chinese Veterinary Herbs, Tongren 554300, Guizhou, China.
authors.forename: Shan Shan
authors.initials: SS
authors.lastname: Liu
authors.affiliation: Key Lab of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chu
authors.affiliation: Key Lab of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Tongren Polytechnic College, Tongren 554300, Guizhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Key Lab of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Tian Yuan
authors.initials: TY
authors.lastname: Zhang
authors.affiliation: Key Lab of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: He
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis; D002645:Chickens; D002691:Chlamydophila psittaci / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D008565:Membrane Proteins / Q000032:analysis; D011201:Poultry Diseases / Q000175:diagnosis* / Q000382:microbiology; D009956:Psittacosis / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D012680:Sensitivity and Specificity
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins
keywords: Chlamydia psittaci; Indirect ELISA; N-terminal fragment of polymorphic membrane protein D; Seroprevalence