title: Studies on serum resistance in Escherichia coli.
abstract: Serum-sensitive mutants and their serum-resistant smooth parental E. coli strains (Wf8, Wf26, and WF 52) have been investigated in respect to their binding of different complement components. These pairs consisting of a wild-type and its mutants represent a better model for the investigation of the mechanism of serum resistance than the comparison of unrelated strains. Both strains of a pair bind equivalent amounts of C3. In binding assays using radiolabeled terminal components C6, C7, C8, and C9, the serum-sensitive strains do bind more late acting components than their resistant parental strains. An active membrane attack complex stably bound to the cell surface was found on the mutants, whereas with wild-type bacteria a complex could be isolated from the supernatant which is composed of the late acting complement components and S-protein. This complex is released from the surface of the wild-type bacteria without participation of C9.
authors.affiliation: Institut für Hygiene und Mikrobiologie, Ruhr-Universität Bochum.
authors.forename: B S
authors.initials: BS
authors.lastname: Kubens
authors.forename: W
authors.initials: W
authors.lastname: Opferkuch
mesh_terms: D001770:Blood Bactericidal Activity; D003176:Complement C3 / Q000378:metabolism; D003183:Complement C6 / Q000378:metabolism; D003184:Complement C7 / Q000378:metabolism; D003185:Complement C8 / Q000276:immunology / Q000378:metabolism; D003186:Complement C9 / Q000276:immunology / Q000378:metabolism; D015938:Complement Membrane Attack Complex; D003165:Complement System Proteins / Q000096:biosynthesis / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D005779:Immunodiffusion; D008070:Lipopolysaccharides / Q000032:analysis; D009154:Mutation
chemical_list: D003176:Complement C3; D003183:Complement C6; D003184:Complement C7; D003185:Complement C8; D003186:Complement C9; D015938:Complement Membrane Attack Complex; D008070:Lipopolysaccharides; D003165:Complement System Proteins