title: Detection of individual microbial pathogens by proximity ligation.
abstract: BACKGROUND
  Nucleic acid amplification allows the detection of single infectious agents. Protein-based assays, although they provide information on ongoing infections, have substantially less detection sensitivity.
  
  
  METHODS
  We used proximity ligation reactions to detect proteins on bacteria and virus particles via nucleic acid amplification. Antibodies recognizing viral or bacterial surface proteins were equipped with DNA strands that could be joined by ligation when several antibodies were bound in proximity to surface proteins of individual infectious agents.
  
  
  RESULTS
  Detection sensitivities similar to those of nucleic acid-based detection reactions were achieved directly in infected samples for a parvovirus and an intracellular bacterium.
  
  
  CONCLUSIONS
  This method enables detection of ligated DNA strands with good sensitivity by real-time PCR and could be of value for early diagnosis of infectious disease and in biodefense.
authors.affiliation: The Beijer Laboratory, Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala, Sweden.
authors.forename: Sigrun M
authors.initials: SM
authors.lastname: Gustafsdottir
authors.forename: Ann
authors.initials: A
authors.lastname: Nordengrahn
authors.forename: Simon
authors.initials: S
authors.lastname: Fredriksson
authors.forename: Per
authors.initials: P
authors.lastname: Wallgren
authors.forename: Esteban
authors.initials: E
authors.lastname: Rivera
authors.forename: Edith
authors.initials: E
authors.lastname: Schallmeiner
authors.forename: Malik
authors.initials: M
authors.lastname: Merza
authors.forename: Ulf
authors.initials: U
authors.lastname: Landegren
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D001431:Bacteriological Techniques; D019921:Biotinylation; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000382:microbiology; D005260:Female; D005333:Fetus / Q000821:virology; D020639:Lawsonia Bacteria / Q000145:classification* / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D021141:Nucleic Acid Amplification Techniques; D010322:Parvoviridae Infections / Q000662:veterinary / Q000821:virology; D028323:Parvovirus, Porcine / Q000145:classification* / Q000235:genetics / Q000276:immunology; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000662:veterinary / Q000821:virology; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000821:virology; D014764:Viral Proteins / Q000032:analysis / Q000235:genetics; D014771:Virion / Q000145:classification / Q000235:genetics; D014773:Virology / Q000379:methods
chemical_list: D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D014764:Viral Proteins