title: Cell surface properties of two differently virulent strains of  Acinetobacter baumannii  isolated from a patient.
abstract: The aim of this study was to unravel, by focusing on cell surface properties, the underlying virulence factors contributing to the difference in the pathogenicity observed in two  Acinetobacter baumannii  strains isolated from the same patient. The two strains were phenotypically different: (i) a mucoid strain (AB-M), highly virulent in a mouse model of pneumonia, and (ii) a nonmucoid strain (AB-NM), moderately virulent in the same model. The study of the cell surface properties included the microbial adhesion to solvents method, the measurement of the electrophoretic mobility of bacteria, the analysis of biofilm formation by calcofluor white staining, the adherence to silicone catheters, and scanning electron microscopy. The AB-NM strain was more hydrophobic, more adherent to silicone catheters, and produced more biofilm than the AB-M strain. Scanning electron microscopy showed bacterial cells with a rough surface and the formation of large cell clusters for AB-NM whereas the AB-M strain had a smooth surface and formed only a few cell clusters. Contrary to the results of most previous studies, cell surface properties were not correlated to the virulence described in our experimental model, indicating that mechanisms other than adherence may be involved in the expression of A. baumannii virulence.
authors.affiliation: Groupe d'étude des interactions hôte-pathogène, UPRES EA 3142, Université d'Angers, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Kempf
authors.forename: Matthieu
authors.initials: M
authors.lastname: Eveillard
authors.forename: Caroline
authors.initials: C
authors.lastname: Deshayes
authors.forename: Sarah
authors.initials: S
authors.lastname: Ghamrawi
authors.forename: Corinne
authors.initials: C
authors.lastname: Lefrançois
authors.forename: Sonia
authors.initials: S
authors.lastname: Georgeault
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bastiat
authors.forename: Harald
authors.initials: H
authors.lastname: Seifert
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Joly-Guillou
mesh_terms: D040981:Acinetobacter baumannii / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity* / Q000648:ultrastructure; D000818:Animals; D001422:Bacterial Adhesion; D016667:Bacterial Capsules / Q000378:metabolism / Q000648:ultrastructure; D018441:Biofilms; D057785:Catheters / Q000382:microbiology; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D051379:Mice; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D014774:Virulence / Q000502:physiology*; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D037521:Virulence Factors