title: Fimbriae and adherence of Stenotrophomonas maltophilia to epithelial cells and to abiotic surfaces.
abstract: Stenotrophomonas maltophilia is an emerging nosocomial bacterial pathogen associated with several infectious diseases and opportunistic infections, especially in immunocompromised patients. These bacteria adhere avidly to medical implants and catheters forming a biofilm that confers natural protection against host immune defences and different antimicrobial agents. The nature of the bacterial surface factors involved in biofilm formation on inert surfaces and in adherence of S. maltophilia to epithelial cells is largely unknown. In this study, we identified and characterized fimbrial structures produced by S. maltophilia grown at 37 degrees C. The S. maltophilia fimbriae 1 (SMF-1) are composed of a 17 kDa fimbrin subunit which shares significant similarities with the N-terminal amino acid sequences of several fimbrial adhesins (G, F17, K99 and 20K) found in Escherichia coli pathogenic strains and the CupA fimbriae of Pseudomonas aeruginosa. All of the clinical S. maltophilia isolates tested produced the 17 kDa fimbrin. Antibodies raised against SMF-1 fimbriae inhibited the agglutination of animal erythrocytes, adherence to HEp-2 cells and biofilm formation by S. maltophilia. High resolution electron microscopy provided evidence of the presence of fimbriae acting as bridges between bacteria adhering to inert surfaces or to cultured epithelial cells. This is the first characterization of fimbriae in this genus. We provide compelling data suggesting that the SMF-1 fimbriae are involved in haemagglutination, biofilm formation and adherence to cultured mammalian cells.
authors.affiliation: Laboratório Clínico do Instituto Dante Pazzanese de Cardiologia, Departamento de Microbiologia do Instituto de Ciências Biomédicas, Universidade de São Paulo, Brazil.
authors.forename: Doroti
authors.initials: D
authors.lastname: de Oliveira-Garcia
authors.forename: Monique
authors.initials: M
authors.lastname: Dall'Agnol
authors.forename: Mónica
authors.initials: M
authors.lastname: Rosales
authors.forename: Ana C G S
authors.initials: AC
authors.lastname: Azzuz
authors.forename: Norma
authors.initials: N
authors.lastname: Alcántara
authors.forename: Marina B
authors.initials: MB
authors.lastname: Martinez
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Girón
mesh_terms: D000595:Amino Acid Sequence; D001422:Bacterial Adhesion / Q000502:physiology*; D018441:Biofilms; D002460:Cell Line; D004847:Epithelial Cells / Q000382:microbiology*; D036781:Fimbriae Proteins / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000378:metabolism* / Q000648:ultrastructure; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D006801:Humans; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D020615:Stenotrophomonas maltophilia / Q000378:metabolism* / Q000648:ultrastructure; D013696:Temperature
chemical_list: D036781:Fimbriae Proteins