title: Analysis of Humoral Immune Responses to Surface and Virulence-Associated Chlamydia abortus Proteins in Ovine and Human Abortions by Use of a Newly Developed Line Immunoassay.
abstract: The obligate intracellular bacterium Chlamydia abortus is the causative agent of enzootic abortion of ewes and poses a significant zoonotic risk for pregnant women. Using proteomic analysis and gene expression library screening in a previous project, we identified potential virulence factors and candidates for serodiagnosis, of which nine were scrutinized here with a strip immunoassay. We have shown that aborting sheep exhibited a strong antibody response to surface (MOMP, MIP, Pmp13G) and virulence-associated (CPAF, TARP, SINC) antigens. While the latter disappeared within 18 weeks following abortion in a majority of the animals, antibodies to surface proteins persisted beyond the duration of the study. In contrast, nonaborting experimentally infected sheep developed mainly antibodies to surface antigens (MOMP, MIP, Pmp13G), all of which did not persist. We were also able to detect antibodies to these surface antigens in C abortus-infected women who had undergone septic abortion, whereas a group of shepherds and veterinarians with occupational exposure to C abortus-infected sheep revealed only sporadic immune responses to the antigens selected. The most specific antigen for the serodiagnosis of human C abortus infections was Pmp13G, which showed no cross-reactivity with other chlamydiae infecting humans. We suggest that Pmp13G-based serodiagnosis accomplished by the detection of antibodies to virulence-associated antigens such as CPAF, TARP, and SINC may improve the laboratory diagnosis of human and animal C abortus infections.
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Ulm, Germany benjamin.hagemann@uniklinik-ulm.de.
authors.forename: Jürgen Benjamin
authors.initials: JB
authors.lastname: Hagemann
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Ulm, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Simnacher
authors.affiliation: Moredun Research Institute, Pentlands Science Park Bush Loan, Edinburgh, Midlothian, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Longbottom
authors.affiliation: Moredun Research Institute, Pentlands Science Park Bush Loan, Edinburgh, Midlothian, United Kingdom.
authors.forename: Morag
authors.initials: M
authors.lastname: Livingstone
authors.affiliation: MIKROGEN GmbH, Neuried, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Maile
authors.affiliation: MIKROGEN GmbH, Neuried, Germany.
authors.forename: Erwin
authors.initials: E
authors.lastname: Soutschek
authors.affiliation: Institute of Hygiene and Medical Microbiology, University of Innsbruck, Innsbruck, Austria.
authors.forename: Gernot
authors.initials: G
authors.lastname: Walder
authors.affiliation: Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Jena, Jena, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Boden
authors.affiliation: Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), Jena, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Sachse
authors.affiliation: Institute of Medical Microbiology and Hygiene, University Hospital of Ulm, Ulm, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Essig
mesh_terms: D000031:Abortion, Septic / Q000175:diagnosis* / Q000662:veterinary*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D002689:Chlamydia / Q000276:immunology*; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000662:veterinary*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D011247:Pregnancy; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis; D037521:Virulence Factors / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D037521:Virulence Factors