title: Influence of freezing stress on morphological alteration and biofilm formation by Listeria monocytogenes: relationship with cell surface hydrophobicity and membrane fluidity.
abstract: The morphological changes and adhesive property of three Listeria monocytogenes strains submitted to freezing stress (-20 °C) were studied. The atomic force micrographs showed a reduction in the cell size and an evolution to coccoid shape. The phenotypic slime production of L. monocytogenes and the expression of the adhesive gene were investigated before and after 10 months of incubation in salmon at -20°. Our results showed that after ten months, stressed stains become more adherent and able to produce slime. In addition, we noted that this pathogen presents same physiological changes to adapt to starvation conditions. The cellular fatty acids composition of adhered and floating cells of three L. monocytogenes strains was taken into consideration. The stressed strains presented different chain lengths and therefore an increase in the hydrophobicity level. Moreover, we noted that the adhesive property of L. monocytogenes strains affects the Benzalkonium chloride bacterial sensitivity which increased after biofilm formation.
authors: Laboratory of Analysis, Treatment and Valorisation of Environment Pollutants and Products, Faculty of Pharmacy, Monastir University, 5000, Monastir, Tunisia, miladi_h@yahoo.fr.
authors: Hanene
authors: H
authors: Miladi
authors: Emna
authors: E
authors: Ammar
authors: Rihab
authors: R
authors: Ben Slama
authors: Nawfel
authors: N
authors: Sakly
authors: Amina
authors: A
authors: Bakhrouf
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001548:Benzalkonium Compounds / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D004203:Disinfection; D005227:Fatty Acids / Q000378:metabolism; D005615:Freezing; D057927:Hydrophobic and Hydrophilic Interactions; D008089:Listeria monocytogenes / Q000737:chemistry / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008560:Membrane Fluidity; D012474:Salmon / Q000382:microbiology*
chemical_list: D001548:Benzalkonium Compounds; D005227:Fatty Acids