title: Diagnosis and molecular typing of rabies virus in samples stored in inadequate conditions.
abstract: BACKGROUND
  The exposure of nervous tissue samples to high temperatures affects the sensitivity of rabies virus diagnostic tests, causing degradation of the viral structure. This study evaluated reverse transcriptase polymerase chain reaction (RT-PCR) for the diagnosis and molecular characterization of brain tissue samples in an advanced state of decomposition and poorly conserved viral isolates by comparing it with routine diagnostic tests.
  
  
  METHODS
  A panel of three canine brain samples exposed to controlled decomposition for 7, 15, 30, and 120 days were evaluated using fluorescence antibody test (FAT), mouse inoculation test (MIT), and RT-PCR. In addition, 14 isolates of rabies variants, representing the largest circulation in Argentina, preserved in inadequate cooling for six to eight years were analyzed. Molecular typing of strains was performed using a 159-nucleotide region corresponding to the nucleoprotein gene.
  
  
  RESULTS
  The three samples analyzed were positive by RT-PCR at all the decomposition times evaluated, in contrast to results observed with FAT and MIT, which rapidly became negative. In addition, 100% of the inadequately preserved samples were characterized molecularly. The limit of detection of RT-PCR was 0.5 MICDL50/0.03 mL.
  
  
  CONCLUSIONS
  RT-PCR can be useful for rabies diagnosis and typing of putrefying samples or rabies isolates stored in inadequate conditions.
authors.affiliation: Instituto de Zoonosis Luis Pasteur, Buenos Aires, Argentina. dcisterna@anlis.gov.ar.
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Beltran
authors.forename: Federico Gury
authors.initials: FG
authors.lastname: Dohmen
authors.forename: Horacio
authors.initials: H
authors.lastname: Del Pietro
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Cisterna
mesh_terms: D000818:Animals; D001921:Brain / Q000821:virology; D004285:Dogs; D005838:Genotype; D060005:Genotyping Techniques; D051379:Mice; D011818:Rabies / Q000175:diagnosis* / Q000821:virology*; D011820:Rabies virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*