title: Rapid and Sensitive Multiplex Detection of Burkholderia pseudomallei-Specific Antibodies in Melioidosis Patients Based on a Protein Microarray Approach.
abstract: The environmental bacterium Burkholderia pseudomallei causes the infectious disease melioidosis with a high case-fatality rate in tropical and subtropical regions. Direct pathogen detection can be difficult, and therefore an indirect serological test which might aid early diagnosis is desirable. However, current tests for antibodies against B. pseudomallei, including the reference indirect haemagglutination assay (IHA), lack sensitivity, specificity and standardization. Consequently, serological tests currently do not play a role in the diagnosis of melioidosis in endemic areas. Recently, a number of promising diagnostic antigens have been identified, but a standardized, easy-to-perform clinical laboratory test for sensitive multiplex detection of antibodies against B. pseudomallei is still lacking.
  
  
  
  In this study, we developed and validated a protein microarray which can be used in a standard 96-well format. Our array contains 20 recombinant and purified B. pseudomallei proteins, previously identified as serodiagnostic candidates in melioidosis. In total, we analyzed 196 sera and plasmas from melioidosis patients from northeast Thailand and 210 negative controls from melioidosis-endemic and non-endemic regions. Our protein array clearly discriminated between sera from melioidosis patients and controls with a specificity of 97%. Importantly, the array showed a higher sensitivity than did the IHA in melioidosis patients upon admission (cut-off IHA titer ≥1:160: IHA 57.3%, protein array: 86.7%; p = 0.0001). Testing of sera from single patients at 0, 12 and 52 weeks post-admission revealed that protein antigens induce either a short- or long-term antibody response.
  
  
  
  Our protein array provides a standardized, rapid, easy-to-perform test for the detection of B. pseudomallei-specific antibody patterns. Thus, this system has the potential to improve the serodiagnosis of melioidosis in clinical settings. Moreover, our high-throughput assay might be useful for the detection of anti-B. pseudomallei antibodies in epidemiological studies. Further studies are needed to elucidate the clinical and diagnostic significance of the different antibody kinetics observed during melioidosis.
authors.affiliation: Friedrich Loeffler Institut for Medical Microbiology, Greifswald, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kohler
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.|Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom.
authors.forename: Susanna J
authors.initials: SJ
authors.lastname: Dunachie
authors.affiliation: Alere Technologies GmbH, Jena, Germany.|InfectoGnostics Research Campus, Jena, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Müller
authors.affiliation: Friedrich Loeffler Institut for Medical Microbiology, Greifswald, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Kohler
authors.affiliation: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Kemajittra
authors.initials: K
authors.lastname: Jenjaroen
authors.affiliation: Sappasithiprasong Hospital, Ubon Ratchathani, Thailand.
authors.forename: Prapit
authors.initials: P
authors.lastname: Teparrukkul
authors.affiliation: Alere Technologies GmbH, Jena, Germany.
authors.forename: Vico
authors.initials: V
authors.lastname: Baier
authors.affiliation: Alere Technologies GmbH, Jena, Germany.|InfectoGnostics Research Campus, Jena, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Ehricht
authors.affiliation: Friedrich Loeffler Institut for Medical Microbiology, Greifswald, Germany.|Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria.
authors.forename: Ivo
authors.initials: I
authors.lastname: Steinmetz
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000918:Antibody Specificity; D016957:Burkholderia pseudomallei / Q000276:immunology*; D006801:Humans; D008554:Melioidosis / Q000276:immunology*; D040081:Protein Array Analysis / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial