title: Immuno-PCR--a new tool for paleomicrobiology: the plague paradigm.
abstract: BACKGROUND
  The cause of past plague pandemics was controversial but several research teams used PCR techniques and dental pulp as the primary material to reveal that they were caused by Yersinia pestis. However, the degradation of DNA limits the ability to detect ancient infections.
  
  
  METHODS
  We used for the first time immuno-PCR to detect Yersinia pestis antigens; it can detect protein concentrations 70 times lower than the standard ELISA. After determining the cut-off value, we tested 34 teeth that were obtained from mass graves of plague, and compared previous PCR results with ELISA and immuno-PCR results.
  
  
  RESULTS
  The immuno-PCR technique was the most sensitive (14 out of 34) followed by the PCR technique (10 out of 34) and ELISA (3 out of 34). The combination of these three methods identified 18 out of 34 (53%) teeth as presumably being from people with the plague.
  
  
  CONCLUSIONS
  Immuno-PCR is specific (no false-positive samples were found) and more sensitive than the currently used method to detect antigens of ancient infections in dental pulp. The combination of three methods, ELISA, PCR and immuno-PCR, increased the capacity to identify ancient pathogens in dental pulp.
authors.affiliation: Aix-Marseille Université, URMITE, UMR CNRS 6236- IRD 198, Faculté de Médecine, Marseille, France.
authors.forename: Nada
authors.initials: N
authors.lastname: Malou
authors.forename: Thi-Nguyen-Ny
authors.initials: TN
authors.lastname: Tran
authors.forename: Claude
authors.initials: C
authors.lastname: Nappez
authors.forename: Michel
authors.initials: M
authors.lastname: Signoli
authors.forename: Cyrille
authors.initials: C
authors.lastname: Le Forestier
authors.forename: Dominique
authors.initials: D
authors.lastname: Castex
authors.forename: Michel
authors.initials: M
authors.lastname: Drancourt
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis; D003782:Dental Pulp / Q000382:microbiology; D004797:Enzyme-Linked Immunosorbent Assay; D049690:History, Ancient; D006801:Humans; D008722:Methods; D010163:Paleontology / Q000379:methods* / Q000592:standards; D010930:Plague / Q000175:diagnosis / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D012680:Sensitivity and Specificity; D014070:Tooth / Q000382:microbiology; D015010:Yersinia pestis / Q000302:isolation & purification*
chemical_list: D000942:Antigens, Bacterial