J Med Microbiol NEW Faster Access
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Schaber, J. A.
Right arrow Articles by Hamood, A. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schaber, J. A.
Right arrow Articles by Hamood, A. N.
Agricola
Right arrow Articles by Schaber, J. A.
Right arrow Articles by Hamood, A. N.
J Med Microbiol 56 (2007), 738-748; DOI: 10.1099/jmm.0.47031-0
© 2007 Society for General Microbiology
ISSN 1473-5644

Diversity of biofilms produced by quorum-sensing-deficient clinical isolates of Pseudomonas aeruginosa

J. Andy Schaber1,2,{dagger}, Adrienne Hammond1,2, Nancy L. Carty1, Simon C. Williams3, Jane A. Colmer-Hamood1, Ben H. Burrowes1, Vijian Dhevan4, John A. Griswold1,2 and Abdul N. Hamood1,2

1 Department of Microbiology and Immunology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA

2 Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA

3 Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA

4 School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA

Correspondence
Abdul N. Hamood
abdul.hamood{at}ttuhsc.edu

Received 27 October 2006
Accepted 5 March 2007

The quorum-sensing (QS) systems control several virulence attributes of Pseudomonas aeruginosa. Five QS-deficient P. aeruginosa clinical isolates (CI) that were obtained from wound (CI-1), tracheal (CI-2, CI-3, CI-4) and urinary tract (CI-5) infections had previously been characterized. In this study, a flow-through continuous-culture system was utilized to examine in detail the biofilms formed by these isolates in comparison with the P. aeruginosa prototrophic strain PAO1. Analysis of the biofilms by confocal laser scanning microscopy and COMSTAT image analysis at 1 and 7 days post-inoculation showed that the isolates produced diverse biofilms. In comparison with PAO1, the CI produced biofilms that scarcely or partially covered the surface at day 1, although CI-1 produced larger microcolonies. At day 7, CI-2 and CI-4 produced mature biofilms denser than that produced by PAO1, while the biofilm formed by CI-1 changed very little from day 1. CI-1 was defective in both swarming and twitching motilities, and immunoblotting analysis confirmed that it produced a reduced level of PilA protein. The twitching-motility defect of CI-1 was not complemented by a plasmid carrying intact pilA. In the 48 h colony biofilm assay, the CI varied in susceptibility to imipenem, gentamicin and piperacillin/tazobactam. These results suggest that: (1) the isolates produced biofilms with different structures and densities from that of PAO1; (2) biofilm formation by the isolates was not influenced by either the isolation site or the QS deficiencies of the isolates; (3) the behaviour of CI-1 in the different biofilm systems may be due to its lack of swarming motility and type IV pilus-related twitching motility.

Abbreviations: 3OC12-HSL, N-(3-oxododecanoyl) homoserine lactone; C4-HSL, N-butyryl homoserine lactone; CF, cystic fibrosis; CI, clinical isolate(s); max. thickness, maximum thickness; QS, quorum sensing; rc, roughness coefficient; sbr, surface-to-biovolume ratio; ssc, substratum surface coverage.

{dagger}Present address: Nikon Instruments, Lewisville, TX 75057, USA.




This article has been cited by other articles:


Home page
 J. Bacteriol.Home page
G. M. Patriquin, E. Banin, C. Gilmour, R. Tuchman, E. P. Greenberg, and K. Poole
Influence of Quorum Sensing and Iron on Twitching Motility and Biofilm Formation in Pseudomonas aeruginosa
J. Bacteriol., January 15, 2008; 190(2): 662 - 671.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
INT J SYST EVOL MICROBIOL J MED MICROBIOL MICROBIOLOGY J GEN VIROL ALL SGM JOURNALS
Copyright © 2007 Society for General Microbiology.