title: Assessing the effects of exposure to environmental stress on some functional properties of Bifidobacterium animalis ssp. lactis.
abstract: This study assessed the effects of exposing a strain of Bifidobacterium animalis ssp. lactis to acid, bile and osmotic stresses on antagonistic properties, biofilm formation and antibiotic susceptibility/resistance profile. Exposure to each stress factor appeared to have no significant effect on the antagonism against Escherichia coli NCTC 12900 and Salmonella enterica serovar Enteritidis PT4. No suppression in biofilm formation due to exposure to stress was observed. Bile and osmotic stresses resulted in significantly higher biofilm formation. Expression of an exopolysaccharide synthesis gene, gtf 01207, was significantly higher when the B. animalis ssp. lactis strain was exposed to osmotic stress. Susceptibility of the B. animalis ssp. lactis strain to chloramphenicol, erythromycin, ampicillin and vancomycin, and resistance to tetracycline remained unchanged when exposed to each stress. The expression of a tetracycline resistance gene, tet(W), was significantly higher when exposed to each stress. These results may suggest that the potential for the B. animalis ssp. lactis strain to provide probiotic benefit, after exposure to the stressful conditions of the gastrointestinal tract, remains intact.
authors.affiliation: Microbiology Research Unit, Faculty of Life Sciences and Computing, London Metropolitan University, 166-220 Holloway Road, London N7 8DB, UK.
authors.forename: O D
authors.initials: OD
authors.lastname: Amund
authors.affiliation: Microbiology Research Unit, Faculty of Life Sciences and Computing, London Metropolitan University, 166-220 Holloway Road, London N7 8DB, UK.
authors.forename: L I I
authors.initials: LI
authors.lastname: Ouoba
authors.affiliation: Microbiology Research Unit, Faculty of Life Sciences and Computing, London Metropolitan University, 166-220 Holloway Road, London N7 8DB, UK.
authors.forename: J P
authors.initials: JP
authors.lastname: Sutherland
authors.affiliation: Microbiology Research Unit, Faculty of Life Sciences and Computing, London Metropolitan University, 166-220 Holloway Road, London N7 8DB, UK.
authors.forename: H B
authors.initials: HB
authors.lastname: Ghoddusi
mesh_terms: D000143:Acids / Q000633:toxicity*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000898:Antibiosis; D001644:Bifidobacterium / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D001646:Bile / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development; D004926:Escherichia coli / Q000254:growth & development; D009997:Osmotic Pressure; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D012477:Salmonella enteritidis / Q000254:growth & development; D013312:Stress, Physiological
chemical_list: D000143:Acids; D000900:Anti-Bacterial Agents; D011135:Polysaccharides, Bacterial
keywords: antibiotic susceptibility; antimicrobial activity; biofilm; gastrointestinal stress; probiotics