title: Viability of Yersinia pestis subcultures in agar stabs.
abstract: Since its identification as the causative agent of plague in 1894, thousands of Yersinia pestis strains have been isolated and stored. Here, we report the ability of Y. pestis to survive up to 47 years in agar stabs, in rubber-stoppered tubes, under refrigeration (+4 to +10°C), although overall subculture recovery rates were poor and inversely related to the length of time stored. Genetic characterization of virulence gene presence among these subcultures was suggestive of significant variation in the genomic stability of Y. pestis subcultures stored under these conditions. Specifically, we found variation in the presence of plasmid and chromosomal virulence markers (genes pla, lcrV, caf1 and irp2) among multiple subcultures of Y. pestis strains in the 'Collection of Yersinia pestis' (Fiocruz-CYP) maintained by the SRP of FIOCRUZ-PE in Brazil. This variation, together with all of the inherent temporal, geographic and other genetic variation represented by all of the recoverable strains in this historical collection was preserved in new frozen culture stocks stored at -70°C as a result of this study. These frozen culture stocks represent a valuable resource for future comparative studies of Y. pestis.
  
  
  CONCLUSIONS
  We report the ability of Yersinia pestis to survive up to 47 years in agar stabs, in rubber-stoppered tubes, under refrigeration (+4 to +10°C), although overall subculture recovery rates were poor and inversely related to the length of time stored. Genetic characterization of virulence gene presence among these subcultures was suggestive of significant variation in the genomic stability of Y. pestis subcultures stored under these conditions. This variation, together with all of the inherent temporal, geographic and other genetic variation represented by all of the recoverable strains in the historical 'Collection of Yersinia pestis' (Fiocruz-CYP) maintained by the SRP of FIOCRUZ-PE in Brazil was preserved in new frozen culture stocks stored at -70°C as a result of this study. These frozen culture stocks represent a valuable resource for future comparative studies of Y. pestis.
authors.affiliation: Centro de Pesquisa Aggeu Magalhães (CPqAM) - FIOCRUZ/PE, Recife, Brazil.
authors.forename: N C
authors.initials: NC
authors.lastname: Leal
authors.affiliation: Centro de Pesquisa Aggeu Magalhães (CPqAM) - FIOCRUZ/PE, Recife, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Sobreira
authors.affiliation: Centro de Pesquisa Aggeu Magalhães (CPqAM) - FIOCRUZ/PE, Recife, Brazil.
authors.forename: A F Q
authors.initials: AF
authors.lastname: Araújo
authors.affiliation: Centro de Pesquisa Aggeu Magalhães (CPqAM) - FIOCRUZ/PE, Recife, Brazil.
authors.forename: J L O
authors.initials: JL
authors.lastname: Magalhães
authors.affiliation: Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Vogler
authors.affiliation: Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Bollig
authors.affiliation: Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: R
authors.initials: R
authors.lastname: Nottingham
authors.affiliation: Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA.|Translational Genomics Research Institute North, Flagstaff, AZ, USA.
authors.forename: P
authors.initials: P
authors.lastname: Keim
authors.affiliation: Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Wagner
authors.affiliation: Centro de Pesquisa Aggeu Magalhães (CPqAM) - FIOCRUZ/PE, Recife, Brazil.
authors.forename: A M P
authors.initials: AM
authors.lastname: Almeida
mesh_terms: D000362:Agar / Q000494:pharmacology*; D001938:Brazil; D015925:Cryopreservation; D014644:Genetic Variation; D006801:Humans; D010930:Plague / Q000382:microbiology; D010957:Plasmids / Q000235:genetics*; D014774:Virulence / Q000235:genetics; D015010:Yersinia pestis / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity
chemical_list: D000362:Agar
keywords: Yersinia pestis; collection; genomic stability; plague; viability