title: Protective effect of Lactobacillus sakei 2a against experimental challenge with Listeria monocytogenes in gnotobiotic mice.
abstract: OBJECTIVE
  Lactobacillus sakei 2a isolated from sausage and presenting an in vitro antagonistic activity against Listeria monocytogenes Scott A was tested for a protective effect in mice experimentally challenged with the enterobacteria.
  
  
  RESULTS
  In the experimental group, germ-free mice (n = 24) were inoculated intragastrically with 0.1 ml of a suspension containing 10(8) colony forming units (CFU) of Lact. sakei and 4 days later the animals were challenged intragastrically with 0.1 ml of a suspension containing 10(8) CFU of L. monocytogenes. Control group (n = 24) was only inoculated with the bacterial pathogen. Faecal counts showed that L. monocytogenes reached similar population levels (10(9) CFU g(-1) of contents) in both the groups. Animals in the control group showed lower (P = 0.0004) survival frequency (58.3%) when compared with the experimental one (100%). Anatomopathological examination confirmed the mortality data.
  
  
  CONCLUSIONS
  Lactobacillus sakei 2a can survive in the mammal digestive tract where showed a protective effect against L. monocytogenes. This phenomenon was not due to an antagonistic activity.
  
  
  CONCLUSIONS
  Use of Lact. sakei 2a as a meat starter could inhibit not only L. monocytogenes growth in the fermented product but also pathogen virulence in the gastrointestinal tract.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: F H S
authors.initials: FH
authors.lastname: Bambirra
authors.forename: K G C
authors.initials: KG
authors.lastname: Lima
authors.forename: B D G M
authors.initials: BD
authors.lastname: Franco
authors.forename: D C
authors.initials: DC
authors.lastname: Cara
authors.forename: R M D
authors.initials: RM
authors.lastname: Nardi
authors.forename: F H F
authors.initials: FH
authors.lastname: Barbosa
authors.forename: J R
authors.initials: JR
authors.lastname: Nicoli
mesh_terms: D000818:Animals; D000898:Antibiosis / Q000502:physiology*; D015169:Colony Count, Microbial; D005243:Feces / Q000382:microbiology; D005856:Germ-Free Life; D007778:Lactobacillus / Q000502:physiology*; D008089:Listeria monocytogenes / Q000254:growth & development*; D008088:Listeriosis / Q000382:microbiology / Q000401:mortality* / Q000473:pathology*; D051379:Mice; D016019:Survival Analysis