title: Aerotolerance of human clinical isolates of Prevotella spp.
abstract: OBJECTIVE
  To determine the influence of oxygen exposure and growth stages on oxygen tolerance for clinical and reference specimens of the genus Prevotella.
  
  
  RESULTS
  Tolerance to oxygen exposure was evaluated along growth stages for a total of four Prevotella isolates constituted by two strains tested soon after isolation from periodontally compromised patients and two reference strains kept frozen (-86 degrees C) in our laboratory collection. Additionally, the recently recovered isolates were also assayed after 4 months exposed to oxygen during laboratory handling. On solid medium, recently recovered Prevotella specimens proved to be less tolerant to oxygen exposure soon after isolation than when exposed for 4 months to oxygen during laboratory handling. Oxygen resistance of reference strains maintained in the laboratory collection showed to be the highest when compared with the clinical isolates both before and after oxygen exposure. When oxygen tolerance was tested during growth, bacterial cells from the exponential phase were more tolerant. Differences were observed in protein patterns between clinical isolates soon after recovery and after laboratory handling as determined by SDS-PAGE of crude cell-free extracts. However, SOD activities were similar in all bacterial samples tested.
  
  
  CONCLUSIONS
  The ability to adaptively change oxygen tolerance was observed for pathogenic specimens of Prevotella. This property may be considered a virulence factor.
  
  
  CONCLUSIONS
  Adaptative aerotolerance of Prevotella as a factor for virulence and survival.
authors.affiliation: Departamento de Microbiologia, ICB-Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: V L
authors.initials: VL
authors.lastname: Silva
authors.forename: M A R
authors.initials: MA
authors.lastname: Carvalho
authors.forename: J R
authors.initials: JR
authors.lastname: Nicoli
authors.forename: L M
authors.initials: LM
authors.lastname: Farias
mesh_terms: D000222:Adaptation, Physiological; D000332:Aerobiosis; D015169:Colony Count, Microbial; D006801:Humans; D010100:Oxygen / Q000494:pharmacology*; D018720:Prevotella / Q000187:drug effects / Q000254:growth & development* / Q000472:pathogenicity; D013482:Superoxide Dismutase / Q000378:metabolism; D014774:Virulence
chemical_list: D013482:Superoxide Dismutase; D010100:Oxygen