title: Identification of Salmonella functions critical for bacterial cell division within eukaryotic cells.
abstract: Salmonella typhimurium multiplication inside eukaryotic host cells is critical for virulence. Salmonella typhimurium strain SL1344 appears as filaments upon growth in macrophages and MelJuSo cells, a human melanoma cell line, indicating a specific blockage in the bacterial cell division process. Several studies have investigated the host cell response impairing bacterial division. However, none looked at the bacterial factors involved in inhibition of Salmonella division inside eukaryotic cells. We show here that blockage in the bacterial division process is sulA-independent and takes place after FtsZ-ring assembly. Salmonella typhimurium genes in which mutations lead to filamentous growth within host cells were identified by a large scale mutagenesis approach on strain 12023, revealing bacterial functions crucial for cell division within eukaryotic cells. We finally demonstrate that SL1344 filamentation is a result of hisG mutation, requires the activity of an enzyme of the histidine biosynthetic pathway HisFH and is specific for the vacuolar environment.
authors.affiliation: Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, Université de la Méditerranée, Case 906, 13288 Marseille Cedex 9, France.
authors.forename: T
authors.initials: T
authors.lastname: Henry
authors.forename: F
authors.initials: F
authors.lastname: García-Del Portillo
authors.forename: J P
authors.initials: JP
authors.lastname: Gorvel
mesh_terms: D000619:Aminohydrolases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D045744:Cell Line, Tumor; D029968:Escherichia coli Proteins / Q000378:metabolism; D005057:Eukaryotic Cells / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D006131:Growth Inhibitors / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012486:Salmonella typhimurium / Q000166:cytology* / Q000254:growth & development / Q000472:pathogenicity; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006131:Growth Inhibitors; C106638:HisG protein, bacteria; D009004:Monosaccharide Transport Proteins; C053139:sulA protein, E coli; D006639:Histidine; C087227:imidazole glycerol phosphate synthase; D000619:Aminohydrolases