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A component of the innate immuneresponse prevents bacterial biofilmdevelopment
Singh, P. K., Parsek, M. R., Greenberg, E. P., and Welsh, M. J.Nature 417:552-5
A Little on BiofilmsA Little on Biofilms Biofilms are communitiesBiofilms are communities
for bacteriafor bacteria
Once established difficultOnce established difficultto removeto remove
Safe haven for bacteriaSafe haven for bacteriafrom from biocidalbiocidal compounds compounds
Link betweenLink betweenenvironmental and clinicalenvironmental and clinical
Donlan and Costerton Clin. Microbiol. Rev. 15:167-93.
Study DesignStudy Design Authors proposed that some factor of the innateAuthors proposed that some factor of the innate
immune response prevents biofilm formationimmune response prevents biofilm formation
LactoferrinLactoferrin - - chelatorchelator of iron, present in bodily of iron, present in bodilysecretionssecretions
GFP expressing GFP expressing P. P. aeruginosaaeruginosa used used
Flow cell chambers for biofilm developmentFlow cell chambers for biofilm development
+/- +/- lactoferrinlactoferrin, , conalbuminconalbumin, or , or deferoxaminedeferoxamine
ConfocalConfocal microscopy with time lapse microscopy with time lapse
Checked biofilm resistance to Checked biofilm resistance to biocidalbiocidalcompounds (compounds (tobramycintobramycin and H and H22OO22))
A Little on Flow CellA Little on Flow Cell
Monitor bacterial attachment in a systemMonitor bacterial attachment in a system
Control rate of flowControl rate of flow
Integrated with microscopy techniquesIntegrated with microscopy techniques
ScopeSlide
FreshMedia
SpentMedia
Iron...Who Cares?Iron...Who Cares? Bacteria, animals, and plants need ironBacteria, animals, and plants need iron
Activity of some enzymes require ironActivity of some enzymes require iron ex: ex: NorRNorR in in E. coliE. coli ( (YgaAYgaA in in S. S. typhimuriumtyphimurium))
Activated by NO in anaerobic environmentActivated by NO in anaerobic environment
NO produced by macrophage (NO produced by macrophage (iNOSiNOS))
D'Autreaux, Tucker, Dixon, & Spiro. Nature 437:769-72.
Figure 2 - Figure 2 - ConfocalConfocalMicroscopyMicroscopy LactoferrinLactoferrin prevented prevented
formation of biofilmformation of biofilm
What if other bacteriaWhat if other bacteriaare present?are present?
4 hrs
7 days
24 hrs
3 days
Figure 3 - Bacteria BehavingFigure 3 - Bacteria BehavingBadlyBadly Squatters -Squatters -
localized in 15 localized in 15 __mmcircle until divisioncircle until division
Ramblers -Ramblers -remained attached,remained attached,but moved outsidebut moved outsidecirclecircle
Flyers - detachedFlyers - detachedfrom surfacefrom surface
Time Lapse MicroscopyTime Lapse Microscopy
Monitored bacterial behavior w/ or w/oMonitored bacterial behavior w/ or w/olactoferrinlactoferrin
Control video (no Control video (no lactoferrinlactoferrin))
Experimental video (with Experimental video (with lactoferrinlactoferrin))
Figure 4 - Twitching MotilityFigure 4 - Twitching Motility Specialized motilitySpecialized motility
mediated by type 4mediated by type 4pilipili Increase in type 4Increase in type 4
genes or proteins?genes or proteins?
40 have been40 have beenidentified in identified in P.P.aeruginosaaeruginosa ((J. S. Mattick,Annual Rev. Microbiol 56:289-314))
Twitching motilityTwitching motilitystimulated by ironstimulated by ironchelatorschelators and may and mayprevent biofilmprevent biofilmformationformation
Fe unsat. lactoferrin
No lactoferrin
lacto. (mutant)
No lacto. (mutant)
Fe sat. lactoferrin
Figure 5 - Biofilm ProtectionFigure 5 - Biofilm Protection Susceptibility to Susceptibility to tobramycintobramycin and H and H22OO22
Presence or absence of iron Presence or absence of iron chelatorchelatorconalbuminconalbumin