title: Phenotypic and genotypic characterization of Stenotrophomonas maltophilia isolates from patients with cystic fibrosis: genome diversity, biofilm formation, and virulence.
abstract: BACKGROUND
  Stenotrophomonas maltophilia is emerging as one of the most frequently found bacteria in cystic fibrosis (CF) patients. In the present study, phenotypic and genotypic traits of a set of 98 isolates of S. maltophilia obtained from clinical (CF and non-CF patients) and environmental sources were comparatively evaluated.
  
  
  RESULTS
  S. maltophilia exhibited a high level of genomic diversity in both CF and non-CF group, thus possibly allowing this bacterium to expand its pathogenic potentials. Strains sharing the same pulsotype infected different patients, thus likely indicating the occurrence of clonal spread or acquisition by a common source. CF isolates differed greatly in some phenotypic traits among each other and also when compared with non-CF isolates, demonstrating increased mean generation time and susceptibility to oxidative stress, but reduced ability in forming biofilm. Furthermore, in CF isolates flagella- and type IV pili-based motilities were critical for biofilm development, although not required for its initiation. Sequential isogenic strains isolated from the same CF patient displayed heterogeneity in biofilm and other phenotypic traits during the course of chronic infection. CF and non-CF isolates showed comparable virulence in a mouse model of lung infection.
  
  
  CONCLUSIONS
  Overall, the phenotypic differences observed between CF and non-CF isolates may imply different selective conditions and persistence (adaptation) mechanisms in a hostile and heterogeneous environment such as CF lung. Molecular elucidation of these mechanisms will be essential to better understand the selective adaptation in CF airways in order to design improved strategies useful to counteract and eradicate S. maltophilia infection.
authors: Center of Excellence on Aging, G. d'Annunzio University Foundation, Via Colle dell'Ara, Chieti, 66100, Italy.
authors: Arianna
authors: A
authors: Pompilio
authors: Stefano
authors: S
authors: Pomponio
authors: Valentina
authors: V
authors: Crocetta
authors: Giovanni
authors: G
authors: Gherardi
authors: Fabio
authors: F
authors: Verginelli
authors: Ersilia
authors: E
authors: Fiscarelli
authors: Giordano
authors: G
authors: Dicuonzo
authors: Vincenzo
authors: V
authors: Savini
authors: Domenico
authors: D
authors: D'Antonio
authors: Giovanni
authors: G
authors: Di Bonaventura
mesh_terms: D000818:Animals; D018441:Biofilms / Q000254:growth & development; D016000:Cluster Analysis; D003550:Cystic Fibrosis / Q000150:complications* / Q000382:microbiology; D004195:Disease Models, Animal; D016521:Electrophoresis, Gel, Pulsed-Field; D010861:Fimbriae, Bacterial / Q000502:physiology; D005407:Flagella / Q000502:physiology; D014644:Genetic Variation; D005838:Genotype; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006801:Humans; D008124:Locomotion; D051379:Mice; D058889:Molecular Typing; D018384:Oxidative Stress; D010641:Phenotype; D018410:Pneumonia, Bacterial / Q000382:microbiology / Q000473:pathology; D012376:Rodent Diseases / Q000382:microbiology / Q000473:pathology; D020615:Stenotrophomonas maltophilia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D013312:Stress, Physiological; D014774:Virulence