TY - JOUR

T1 - Heterogeneity of biofilms formed by nonmucoid Pseudomonas aeruginosa isolates from patients with cystic fibrosis.

AU - Lee, Baoleri

AU - Haagensen, Janus A J

AU - Ciofu, Oana

AU - Andersen, Jens Bo

AU - Høiby, Niels

AU - Molin, Søren

N1 - Keywords: Biofilms; Cystic Fibrosis; Humans; Image Processing, Computer-Assisted; Microscopy, Confocal; Phenotype; Pseudomonas Infections; Pseudomonas aeruginosa

PY - 2005

Y1 - 2005

N2 - Biofilms are thought to play a key role in the occurrence of lung infections by Pseudomonas aeruginosa in patients with cystic fibrosis (CF). In this study, 20 nonmucoid P. aeruginosa isolates collected during different periods of chronic infection from eight CF patients were assessed with respect to phenotypic changes and in vitro biofilm formation. The physiological alterations were associated with a loss of motility (35% were nonmotile) and with decreased production of virulence factors (pyocyanin, proteases) and quorum-sensing molecules (45% of the isolates were unable to produce 3-O-C(12)-homoserine lactone quorum-sensing molecules). Compared with wild-type strain PAO 1, most P. aeruginosa isolates demonstrated different degrees of reduction of adherence on polystyrene surfaces. The in vitro biofilm formation of isolates was investigated in a hydrodynamic flow system. Confocal laser scanning microscope analysis showed that the biofilm structures of the P. aeruginosa isolates were highly variable in biomass and morphology. Biofilm development of six genotypically identical sequential isolates recovered from a particular patient at different time points of chronic infection (20 years) and after lung transplantation demonstrated significant changes in biofilm architectures. P. aeruginosa biofilm formation followed a trend of decreased adherence with progression of the chronic lung infection. The results suggest that the adherent characteristic of in vitro biofilm development was not essential for the longitudinal survival of nonmucoid P. aeruginosa during chronic lung colonization.

AB - Biofilms are thought to play a key role in the occurrence of lung infections by Pseudomonas aeruginosa in patients with cystic fibrosis (CF). In this study, 20 nonmucoid P. aeruginosa isolates collected during different periods of chronic infection from eight CF patients were assessed with respect to phenotypic changes and in vitro biofilm formation. The physiological alterations were associated with a loss of motility (35% were nonmotile) and with decreased production of virulence factors (pyocyanin, proteases) and quorum-sensing molecules (45% of the isolates were unable to produce 3-O-C(12)-homoserine lactone quorum-sensing molecules). Compared with wild-type strain PAO 1, most P. aeruginosa isolates demonstrated different degrees of reduction of adherence on polystyrene surfaces. The in vitro biofilm formation of isolates was investigated in a hydrodynamic flow system. Confocal laser scanning microscope analysis showed that the biofilm structures of the P. aeruginosa isolates were highly variable in biomass and morphology. Biofilm development of six genotypically identical sequential isolates recovered from a particular patient at different time points of chronic infection (20 years) and after lung transplantation demonstrated significant changes in biofilm architectures. P. aeruginosa biofilm formation followed a trend of decreased adherence with progression of the chronic lung infection. The results suggest that the adherent characteristic of in vitro biofilm development was not essential for the longitudinal survival of nonmucoid P. aeruginosa during chronic lung colonization.

U2 - 10.1128/JCM.43.10.5247-5255.2005

DO - 10.1128/JCM.43.10.5247-5255.2005

M3 - Journal article

C2 - 16207991

VL - 43

SP - 5247

EP - 5255

JO - Journal of Clinical Microbiology

JF - Journal of Clinical Microbiology

SN - 0095-1137

IS - 10

ER -