biofilms-091008210814-phpapp02 imp.ppt

7/26/2019 biofilms-091008210814-phpapp02 imp.ppt

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Beginning of MicrobesBeginning of Microbes

Bacteria frst appearedBacteria frst appearedon earth about 3.6on earth about 3.6billion years ago, longbillion years ago, longbeore the appearancebeore the appearance

oo Homo sapiensHomo sapiensaroundaround100,000 years ago..100,000 years ago..Van LeeuwenhoekVan Leeuwenhoekwas the frst person towas the frst person tovisualize, graphicallyvisualize, graphicallyillustrate, and labelillustrate, and label"anialcules" !bacteria"anialcules" !bacteriathat he ound inthat he ound inplaqueplaquescraped ro his ownscraped ro his ownteeth.teeth.


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#he ter biofl was introduced to designate the#he ter biofl was introduced to designate the

thinlayered condensations o icrobesthinlayered condensations o icrobes

!e.g.bacteria, ungi, protozoa that ay occur on!e.g.bacteria, ungi, protozoa that ay occur on

various surace structures in nature. $ree%&oatingvarious surace structures in nature. $ree%&oating

bacteria e'isting in an a(ueous environent,so%bacteria e'isting in an a(ueous environent,so%

calledplan)tonicicroorganiss,are acalledplan)tonicicroorganiss,are a

prere(uisite or biofl oration. *uch flsprere(uisite or biofl oration. *uch fls

ay thus becoe established on any organic oray thus becoe established on any organic or

inorganic surace substrate where plan)tonicinorganic surace substrate where plan)tonicicroorganiss prevail in a water%basedicroorganiss prevail in a water%based

solution.solution.


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Despite the discovery of microbial biolms as far back asthe 17thcentury, scientists have largely focused their attentions onthe solitary,or planktonic, forms of microorganisms.

In nature, hoever, most microorganisms live together inlargecommunities attached to a surface+ere, bacteria ree in saliva !plan)tonic organiss serve as thepriary source or the organization o this specifc biofl !1


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Biofls were already discovered by one o theBiofls were already discovered by one o the

frst icrobiologist, the utch -ntonie vanfrst icrobiologist, the utch -ntonie van

eeuwenhoe) in 16/0s, but the actualeeuwenhoe) in 16/0s, but the actual

brea)through o the phenoenon had to waitbrea)through o the phenoenon had to wait

another 3 years until 2osterton andanother 3 years until 2osterton and

colleagues published their wor) on +owcolleagues published their wor) on +ow

Bacteria *tic)4 in 15. *ince 15 theBacteria *tic)4 in 15. *ince 15 the

research within biofl bacteria has e'ploded.research within biofl bacteria has e'ploded.

#he inherent high tolerance to antiicrobials#he inherent high tolerance to antiicrobials

and iune cells e'plain its vast iplication inand iune cells e'plain its vast iplication in

chronic inections.chronic inections.


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Bacteria are ound in at least two distinct states 7Bacteria are ound in at least two distinct states 7

either as plan)tonic or sessile cells. 8lan)toniceither as plan)tonic or sessile cells. 8lan)tonic

cells are classically defned as ree &owingcells are classically defned as ree &owing

bacteria in suspension4 as opposed to the sessilebacteria in suspension4 as opposed to the sessile

state !the so called biofl9 a structuredstate !the so called biofl9 a structuredcounity o bacterial cells enclosed in a sel%counity o bacterial cells enclosed in a sel%

produced polyeric atri' and adherent to anproduced polyeric atri' and adherent to an

inert or living surace4 as stated by 2osterton andinert or living surace4 as stated by 2osterton and

cowor)ers !1555. :n the above section sessilecowor)ers !1555. :n the above section sessilegrowing bacteria were defned as an asseblagegrowing bacteria were defned as an asseblage

o cells ebedded 4in a sel%produced polyerico cells ebedded 4in a sel%produced polyeric

atri'atri'


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efnition o a Bioflefnition o a Biofl

Biofl can be defned as a sessileBiofl can be defned as a sessile

ulticellular icrobial counityulticellular icrobial counity

characterised by cells that are frlycharacterised by cells that are frly

attached to a surace and eneshedattached to a surace and eneshed

in a sel produced atri' oin a sel produced atri' o

e'tracellular polyeric substancee'tracellular polyeric substance

usually polyssacharideusually polyssacharide


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efnition o a Bioflefnition o a Biofl

BioflsBioflsare counities oare counities o

icroorganiss in a atri' that ;oins theicroorganiss in a atri' that ;oins the

together and to living or inert substratestogether and to living or inert substrates

BioflsBioflsare surace%attached counitiesare surace%attached counitieso bacteria, encased in an e'tracellularo bacteria, encased in an e'tracellular

atri' o secreted proteins,atri' o secreted proteins,

carbohydrates, and


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Biofl are not erely passiveBiofl are not erely passive

asseblage o bacterial cells that areasseblage o bacterial cells that are

stuc) to surace they are structurallystuc) to surace they are structurally

and dynaically organized cople'and dynaically organized cople'

biologic syste.biologic syste.


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Biofl orationBiofl oration

#he frst step is the#he frst step is the attachentattachento theo thebacterial cells to the selected abiotic orbacterial cells to the selected abiotic or

biotic suracebiotic surace

:nitial attachent is ediated through:nitial attachent is ediated throughwea) reversible van der >aalswea) reversible van der >aalsinteractionsinteractions

between the cell surace and thebetween the cell surace and thesubstratu, which can lead to strongersubstratu, which can lead to strongeradhesion receptor ediated attachentadhesion receptor ediated attachent


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Bacterial cell surace structures such asBacterial cell surace structures such as&agella&agella,, fbriaefbriae,, 8*8*, and, ande'opolysaccharidese'opolysaccharidesparticipate inparticipate inirreversibleirreversibleinteractionsinteractions

#he second step corresponds to the#he second step corresponds to the

developent odevelopent o icro%coloniesicro%coloniesprooted by the growth and division oprooted by the growth and division othe frst attached cells !priarythe frst attached cells !priarycolonizerscolonizers


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#he icro%colonies progressively#he icro%colonies progressively

enlargeenlarge

and coalesce to or theand coalesce to or the

frstfrst

layer o cellslayer o cells covering the suracecovering the surace

>hen>hen ultiple layersultiple layers o cells pile upo cells pile upon the surace, the third step o theon the surace, the third step o the

oration is obtainedoration is obtained


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indicated by the presence oindicated by the presence o a aturea aturebioflbiofl characterized by the presence ocharacterized by the presence oacro%coloniesacro%coloniessurrounded bysurrounded by waterwater

channelschannels that help distribute nutrientsthat help distribute nutrientsand signaling oleculesand signaling olecules

$inally, to survive when$inally, to survive when nutrientsnutrients

becoe liitedbecoe liited, or siply to spread and, or siply to spread andcolonize to other niches, soe bioflcolonize to other niches, soe bioflcells cancells can detachdetachindividually or in clupsindividually or in clups


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copositioncoposition

1/? bacterial icrocolonie1/? bacterial icrocolonie

/? e'tracellular polysaccharide/? e'tracellular polysaccharide

atri'atri'

Both o these are separated by waterBoth o these are separated by water

channelschannels


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Biofl *tructureBiofl *tructure

biofls display a coon attribute, thebiofls display a coon attribute, thebioflbioflatri'atri'..

2ontrary to ree%&oating plan)tonic cells,2ontrary to ree%&oating plan)tonic cells,biofl cells are ebedded in a sel producedbiofl cells are ebedded in a sel producede'tracellular atri', thee'tracellular atri', the e'tracellulare'tracellularpolyeric substancepolyeric substance!@8*, that!@8*, that holds theholds thetogethertogether

Biofls are coposed o aboutBiofls are coposed o about 07/? @8*07/? @8*!by volue and only!by volue and only 1/70? cells1/70? cells !by volue!by volue


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-lthough the-lthough the @8*@8*ay vary in cheicalay vary in cheical

and physical properties, its a;orand physical properties, its a;or

coponents arecoponents are polysaccharidespolysaccharides,,

proteinsproteins, and, and e'tracellular =-e'tracellular =-

#he @8* plays a a;or role in#he @8* plays a a;or role in

aintaining the integrityaintaining the integrityo the bioflo the biofland can coner other benefcialand can coner other benefcial

properties.properties.


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*ince the @8* is also*ince the @8* is also highly hydratedhighly hydrated, it, it

can preventcan prevent desiccationdesiccationin soe naturalin soe natural

bioflsbiofls

#he @8* can also act as a#he @8* can also act as a diAusiondiAusion

barrierbarrier, preventing, preventing to'ic substancesto'ic substancessuch as antibiotics and disinectantssuch as antibiotics and disinectants

ro reaching their targetro reaching their target


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2ell heterogeneity within2ell heterogeneity within

bioflsbiofls

ost biofls ound in nature areost biofls ound in nature are

polyicrobialspolyicrobials, where diverse, where diverse

species e'pressing ultiplespecies e'pressing ultiple

phenotypes are involvedphenotypes are involved

#he ost aazing act is that even#he ost aazing act is that even

in ain a ono%speciesono%speciesbiofl,biofl,

phenotypic heterogeneityphenotypic heterogeneitye'istse'ists


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2ell diAerentiation2ell diAerentiation in biofls ayin biofls ay

depend on thedepend on the local environentallocal environental

conditions surrounding the cellsconditions surrounding the cells

iAerent concentrationiAerent concentrationgradients ogradients o

o'ygeno'ygen,, nutrientsnutrients,, ionsions, and, and cheicalscheicals

create a wide variety o icrohabitatscreate a wide variety o icrohabitatsproviding conditions suitable orproviding conditions suitable or

bacterial colonizationbacterial colonization


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2ells located in the2ells located in the upper biofl layersupper biofl layersconsue all available o'ygen andconsue all available o'ygen and growgrowaerobicallyaerobically, while an, while an anaerobicanaerobicicro%nicheicro%nichedevelopeddeveloped underneathunderneaththe aerobic layerthe aerobic layer

C'ygen% and nutrient depletedC'ygen% and nutrient depleted regions areregions areound at theound at the botto layersbotto layers o the bioflo the biofl

structure and under these circustances,structure and under these circustances,ost o the sessile cells are etabolicallyost o the sessile cells are etabolicallyinactiveinactiveoror deaddead


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2ounication language in2ounication language in

bioflbiofl

- ew years ago, >atnic) D Eolter- ew years ago, >atnic) D Eolter

proposed the interesting idea thatproposed the interesting idea that

biofls can be copared to citiesbiofls can be copared to cities

:n these cities o icrobes,:n these cities o icrobes,

icroorganiss are consideredicroorganiss are considered

socialsocial4 organiss4 organiss able toable to

counicatecounicatewith one anotherwith one another


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Fsing diAerent cheical languages,Fsing diAerent cheical languages,

bacteria learn about their currentbacteria learn about their current cellcell

populationpopulation and deterine when theyand deterine when they

havehave reached a critical assreached a critical ass

Fsing that inoration, bacteria canFsing that inoration, bacteria can

thusthus odiy their behaviorodiy their behavior to carry outto carry outprocesses that would re(uireprocesses that would re(uire any cellsany cells

acting in con;unction to be eAectiveacting in con;unction to be eAective


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2ell%to%cell counication2ell%to%cell counication is generallyis generallycarried out bycarried out by diAusible signaldiAusible signaloleculesolecules produced and released byproduced and released by

bacteriabacteria

>hen bacteria are growing within a>hen bacteria are growing within abioflbiofl, they, they secrete signalingsecrete signalingoleculesolecules !auto%inducers that increase!auto%inducers that increasein concentration as a unction oin concentration as a unction obacterialbacterial cell densitycell density


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:n a process called:n a process called (uoru sensing(uoru sensing,,

bacteria counicate with onebacteria counicate with one

another by usinganother by using auto%inducersauto%inducerstoto

regulate their gene e'pression inregulate their gene e'pression inresponseresponseto &uctuations in theto &uctuations in the cellcell

population densitypopulation density

#wo types#wo types o (uoru%sensing systeso (uoru%sensing systes

are recognized in bacteria9are recognized in bacteria9


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intra%speciesintra%speciescounication andcounication and

inter%speciesinter%speciescounicationcounication

uringuringintra%speciesintra%species counication,counication,

several auto%inducersseveral auto%inducershave beenhave beenidentifedidentifed


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Gra%negativeGra%negativebacteria usually usebacteria usually use

acyl hooserine lactone !-+acyl hooserine lactone !-+ asas

signal olecules, whilesignal olecules, while Gra%positiveGra%positivebacteria utilizebacteria utilize sall peptidessall peptides

uringuring inter%speciesinter%speciescounication,counication,bacteria usebacteria use autoinducer% !-:%autoinducer% !-:%


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2ells located in the2ells located in the upper biofl layersupper biofl layersconsue all available o'ygen andconsue all available o'ygen and growgrowaerobicallyaerobically, while an, while an anaerobicanaerobicicro%nicheicro%nichedevelopeddeveloped underneathunderneaththe aerobic layerthe aerobic layer

C'ygen% and nutrient depletedC'ygen% and nutrient depleted regions areregions areound at theound at the botto layersbotto layers o the bioflo the biofl

structure and under these circustances,structure and under these circustances,ost o the sessile cells are etabolicallyost o the sessile cells are etabolicallyinactiveinactiveoror deaddead


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:n soe cases, (uoru sensing does:n soe cases, (uoru sensing doesnot see to be involved in bioflnot see to be involved in bioflstructural developentstructural developent

while or other species, there iswhile or other species, there isevidence that (uoru sensing isevidence that (uoru sensing isiportant or theiportant or the attachentattachentoo

bacteria to the surace, thebacteria to the surace, the aturationaturationo the biofl, or the control o eventso the biofl, or the control o eventsleading to theleading to the dispersiondispersiono cellso cells


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ulti%drug tolerance oulti%drug tolerance o

bioflsbiofls - signifcant characteristic o icrobial- signifcant characteristic o icrobial

biofls is theirbiofls is their high%level drughigh%level drug

tolerancetolerance

Bacterial biofls have been shown toBacterial biofls have been shown to

have ahave a 100% to 1,000% old100% to 1,000% old increasedincreased

tolerance toward antibiotics intolerance toward antibiotics incoparison to their ree%swiingcoparison to their ree%swiing

counterpartscounterparts


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iAusion barrier iparted by the @8* atri'iAusion barrier iparted by the @8* atri'

8henotypic heterogeneity8henotypic heterogeneity

Gene #ranserringGene #ranserring

*ecretion o antibiotic degrading enzyes*ecretion o antibiotic degrading enzyes


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8rotective role o @8* atri'8rotective role o @8* atri'

- priary unction that has been- priary unction that has been

attributed to the biofl atri' isattributed to the biofl atri' is

protectionprotection,,

*everal studies have shown that the*everal studies have shown that the

@8* atri' can act as an ipereable@8* atri' can act as an ipereable

barrier tobarrier to liit antiicrobialliit antiicrobialpenetrationpenetration, thereby protecting the, thereby protecting the

biofl cellsbiofl cells


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*uch protection can be due either to*uch protection can be due either to

physical hindrancephysical hindrancein antiicrobialin antiicrobial

diAusion or todiAusion or to direct bindingdirect bindingo theo the

antibiotics by the @8* atri'antibiotics by the @8* atri'

Fpon antibiotic treatent, cells at theFpon antibiotic treatent, cells at the toptopo the li(uid7 biofl interaceo the li(uid7 biofl interace diediedue todue to

their closer e'posure, while bacteriatheir closer e'posure, while bacteriaebeddedebedded deepdeepinside the biofl are ableinside the biofl are able

toto survivesurvive


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-nionic @8*-nionic @8* atri' can bind andatri' can bind and

se(uester to'icse(uester to'ic cationic heavycationic heavy

etalsetals,, cationic antiicrobialcationic antiicrobial

peptidespeptides, and, and positively%chargedpositively%charged

antibioticsantibiotics!e.g. ainoglycosides!e.g. ainoglycosides


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8henotypic heterogeneity8henotypic heterogeneity

8henotypic8henotypic heterogeneityheterogeneityoccurs withinoccurs withinbiofls notably due tobiofls notably due to diAerentdiAerentconcentration gradientsconcentration gradients

2ells localized at the2ells localized at the botto layersbotto layers o theo thebiofl are norally ound in a growthbiofl are norally ound in a growthstage analogous tostage analogous to stationary%phasestationary%phase

plan)tonic cells, while the physiology oplan)tonic cells, while the physiology ocells localized at thecells localized at the toptopsurace layers issurace layers issiilar tosiilar to e'ponentially growinge'ponentially growing plan)tonicplan)toniccellscells


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icrobial cells, especially those in theicrobial cells, especially those in thedeeper layersdeeper layers o the biofls whereo the biofls wherenutrients and o'ygen are liited, arenutrients and o'ygen are liited, are

associated with aassociated with a lower growth ratelower growth rate

#his#his reduced etabolic activityreduced etabolic activity ightightaccount or the enhancedaccount or the enhanced tolerancetolerance

toward antibioticstoward antibioticsthat target bacterialthat target bacterialcellular processes such as =-cellular processes such as =-replication or translationreplication or translation


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2onventional2onventional antibioticsantibioticsused to treatused to treat

inections are ostly eAective atinections are ostly eAective at )illing)illingrapidly growingrapidly growing cellscells

#he#he decreased etabolic activitydecreased etabolic activity oo

cells ound within the deeper bioflcells ound within the deeper biofl

layers ay thus contribute tolayers ay thus contribute to antibioticantibiotictolerancetolerance and the persistence oand the persistence o

biofl inectionsbiofl inections


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Gene #ranserGene #ranser

Biofls also provide anBiofls also provide an ideal nicheideal niche

or theor the e'changee'changeoo

e'trachroosoal =- !e'trachroosoal =- !plasidsplasids

2on;ugation !the echanis o2on;ugation !the echanis o

plasid transer occurs atplasid transer occurs at a greatera greater

raterate between cells in biofls thanbetween cells in biofls than

between plan)tonic cellsbetween plan)tonic cells


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*ecretion o antibiotic*ecretion o antibiotic

degrading enzyesdegrading enzyes


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Bio lm constitutesBio lm constitutes

--biolmbiolmis an aggregate ois an aggregate o

icroorganiss in which cells are stuc)icroorganiss in which cells are stuc)

to each other and


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Biolm is a comple!Biolm is a comple!

substance.substance. - biofl is a cople'- biofl is a cople'

aggregation oaggregation o

icroorganiss growingicroorganiss growing

on a solid substrate.on a solid substrate.

Biofls areBiofls arecharacterized bycharacterized by

structural heterogeneity,structural heterogeneity,

genetic diversity,genetic diversity,

cople' counitycople' counity

interactions, and aninteractions, and ane'tracellular atri' oe'tracellular atri' o

polyeric substances.polyeric substances.

Biofls ound in =atureBiofls ound in =ature


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Biofls ound in =atureBiofls ound in =ature

everywhere where is there iseverywhere where is there is

oistureoisture

More properly known asMore properly known as bioflmbioflm,,

slime cities thrive wherever there isslime cities thrive wherever there is

water - in the kitchen, on contactwater - in the kitchen, on contact

lenses, in the gut linings of animals.lenses, in the gut linings of animals.When the urban sprawl is extensive,When the urban sprawl is extensive,

bio lms can be seen with the nakedbio lms can be seen with the naked

eye, coating the inside of water pipeseye, coating the inside of water pipesor dangling slippery and green fromor dangling slippery and green from

plumbingplumbing."." "#oghlan 1$$%&"#oghlan 1$$%&

i l hBi l h


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Biolm supports theBiolm supports the

Bacterial grothBacterial groth Biofl are a coon ode o bacterialBiofl are a coon ode o bacterial

growth in nature and their presence has angrowth in nature and their presence has anenorous ipact on any aspects o ourenorous ipact on any aspects o ourlives, such as sewage treatent, corrosion olives, such as sewage treatent, corrosion o

aterials, ood containation duringaterials, ood containation duringprocessing, pipe collapse, plant%processing, pipe collapse, plant%icroorganiss interaction in the biosphere,icroorganiss interaction in the biosphere,the oration o dental pla(ue, thethe oration o dental pla(ue, the

developent o chronic inections in livedevelopent o chronic inections in livetissue !astitis, Ctitis, pneuonia, urinarytissue !astitis, Ctitis, pneuonia, urinaryinections, osteoyelitis or probles relatedinections, osteoyelitis or probles relatedto edical iplants.to edical iplants.


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'ormation of Biolms'ormation of Biolms

Biofls ay orBiofls ay or

on living or non%on living or non%

living suraces,living suraces,

and represent aand represent aprevalent ode oprevalent ode o

icrobial lie inicrobial lie in

natural, industrialnatural, industrial

and hospitaland hospital

settingssettings

Bi fl i - ibi iBi fl i - tibi ti


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Biofls increases -ntibioticBiofls increases -ntibiotic

resitanceresitance

>ith>ith

icroorganissicroorganiss

are highlyare highlyresistant toresistant to

antiicrobialantiicrobial

treatent and aretreatent and are

tenaciously boundtenaciously boundto the suraceto the surace

h i i Bi fl h i i Bi fl


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echanisis o Bioflechanisis o Biofl

orationoration 'ormation of a biolm'ormation of a biolm

begins ith thebegins ith theattachment of free(attachment of free()oating microorganisms)oating microorganismsto a surface. *hese rstto a surface. *hese rstcolonists adhere to thecolonists adhere to thesurface initially throughsurface initially through

eak, reversible van dereak, reversible van der+aals forces.+aals forces.If theIf thecolonists are notcolonists are notimmediatelyimmediatelyseparated from theseparated from thesurface, they cansurface, they can

anchor themselvesanchor themselvesmore permanentlymore permanentlyusing cell adhesionusing cell adhesionstructures such as pilistructures such as pili

$actors :n&uencing Hate and$actors :n&uencing Hate and


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$actors :n&uencing Hate and$actors :n&uencing Hate and@'tent o Biofl $oration@'tent o Biofl $oration

:ndwelling edical device when containated:ndwelling edical device when containated

with icroorganiss, several variableswith icroorganiss, several variables

deterine whether a biofl develops. $irstdeterine whether a biofl develops. $irst

the icroorganiss ust adhere to thethe icroorganiss ust adhere to the

e'posed suraces o the device long enough toe'posed suraces o the device long enough tobecoe irreversibly attached. #he rate o cellbecoe irreversibly attached. #he rate o cell

attachent depends on the nuber and typesattachent depends on the nuber and types

o cells in the li(uid to which the device iso cells in the li(uid to which the device is

e'posed, the &ow rate o li(uid through thee'posed, the &ow rate o li(uid through thedevice, and the physicocheicaldevice, and the physicocheical

characteristics o the suracecharacteristics o the surace

* h l d t d* h l d t d


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*echnology understands*echnology understands

Biolms betterBiolms better #echnological progress in#echnological progress in

icroscopy, olecularicroscopy, olecular

genetics and genoegenetics and genoe

analysis has signifcantlyanalysis has signifcantly

advanced ouradvanced ourunderstanding o theunderstanding o the

structural and olecularstructural and olecular

aspects o biofls,aspects o biofls,

especially o e'tensivelyespecially o e'tensively

studied odelstudied odelorganiss such asorganiss such as

PseudomonasPseudomonas

aeruginosaaeruginosa..

-t i Bi l-t i Bi l


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-teps in Biolm-teps in Biolm

DevelopmentDevelopment Biofl developent canBiofl developent can

be divided into severalbe divided into several

)ey steps including)ey steps including

attachent, icroattachent, icrocolony oration, bioflcolony oration, biofl

aturation andaturation and

dispersionI and in eachdispersionI and in each

step bacteria ay recruitstep bacteria ay recruit

diAerent coponentsdiAerent coponents

and olecules includingand olecules including

&agella, type :J pili, =-&agella, type :J pili, =-

and e'o polysaccharides.and e'o polysaccharides.

-t f bi l-t f bi l


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-tages of biolm-tages of biolm

developmentdevelopment..



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formationformation

B t i i t d ithBacteria associated ith


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Bacteria associated ithBacteria associated ith

Biolms dierBiolms dier Bacteria living in a biofl can haveBacteria living in a biofl can have

signifcantly diAerent properties rosignifcantly diAerent properties roree%&oating bacteria, as the dense andree%&oating bacteria, as the dense andprotected environent o the fl allowsprotected environent o the fl allowsthe to cooperate and interact in variousthe to cooperate and interact in variousways. Cne beneft o this environent isways. Cne beneft o this environent isincreased resistance to detergents andincreased resistance to detergents andantibiotics, as the dense e'tracellularantibiotics, as the dense e'tracellularatri' and the outer layer o cells protectatri' and the outer layer o cells protectthe interior o the counity.the interior o the counity.

Bi fl ; Biofls a;or cause o


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Biofls a;or cause oBiofls a;or cause o

=osocoial inections=osocoial inections icrobial biofls,icrobial biofls,

which oten arewhich oten are

ored byored by

antiicrobial%antiicrobial%

resistantresistant

organiss, areorganiss, are

responsible orresponsible or

6/? o inections6/? o inectionstreated in thetreated in the

developed world.developed world.

Biofls a Great threat toBiofls a Great threat to


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Biofls a Great threat toBiofls a Great threat to

:plants:plants - signifcant nuber o people are- signifcant nuber o people are

aAected by biofl inections whichaAected by biofl inections which

develop on edical devices iplanted indevelop on edical devices iplanted in

the body such as catheters !tubes used tothe body such as catheters !tubes used toconduct &uids in or out o the body,conduct &uids in or out o the body,

artifcial ;oints, and echanical heartartifcial ;oints, and echanical heart

valves. >hen iplanted aterialvalves. >hen iplanted aterial

becoes colonized by icroorganiss, abecoes colonized by icroorganiss, aslow developing but persistent inectionslow developing but persistent inection

results.results.

Biofls a Gr oing concern inBiofls a Grwoing concern in


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Biofls a Grwoing concern inBiofls a Grwoing concern in

odern edicineodern edicine

8rosthetic device inections, such as8rosthetic device inections, such as

those involving artifcial heart valves,those involving artifcial heart valves,

intravascular catheters, or prostheticintravascular catheters, or prosthetic

;oints, are prie e'aples o biofl%;oints, are prie e'aples o biofl%associated inections. >ith theassociated inections. >ith the

increasing use o such devices in theincreasing use o such devices in the

odern practice o edicine, theodern practice o edicine, theprevalence o these inections isprevalence o these inections is

e'pected to increase.e'pected to increase.


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Dental pla/ueDental pla/ue

ental pla(ue is aental pla(ue is a

yellowish bioflyellowish biofl

that build up onthat build up on

the teeth. : notthe teeth. : notreoved regularly,reoved regularly,

it can lead toit can lead to

dental caries.dental caries.


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Dental pla/uesDental pla/ues

#he oration o#he oration odental pla(ue biodental pla(ue bio

fls includes afls includes a

series o steps thatseries o steps that

begins with thebegins with theinitial colonizationinitial colonization

o the pellicle ando the pellicle and

ends with theends with the

cople' orationcople' oration

o a ature bio fl.o a ature bio fl.

'ormation of Dental'ormation of Dental


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o a o o e ao a o o e aBiolmsBiolms

-dditionally, through-dditionally, throughthe growth process othe growth process o

the pla(ue bio fl, thethe pla(ue bio fl, theicrobial copositionicrobial coposition

changes ro one thatchanges ro one thatis priarily gra%is priarily gra%

positive andpositive and

streptococcus%rich to astreptococcus%rich to astructure flled withstructure flled with

gra%negativegra%negativeanaerobes in its oreanaerobes in its ore

ature state.ature state.

e %ce s gna ng e'.e %ce s gna ng e'. /uorum/uorumii d i ti ith d i ti ith


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sensingsensing, and counication with, and counication with

diAerent bacteria enhance BiofldiAerent bacteria enhance Biofl

orationoration


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65/107

Bioflms everywhereBioflms everywhere

#heyKre everywhere9#heyKre everywhere9on your showeron your shower

curtain, on edicalcurtain, on edical

devices iplanted indevices iplanted in

patients, on roc)s inpatients, on roc)s inrivers and streas,rivers and streas,

and in your nose.and in your nose.

>hile the sheer>hile the sheer

nuber o diAerentnuber o diAerent

organiss a bioflorganiss a biofl

ay contain a)es itay contain a)es it

a challenge to study,a challenge to study,


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#D##D#77 on Bioflson Biofls

Biofls or on the surace oBiofls or on the surace o

catheter lines and contact lenses.catheter lines and contact lenses.

#hey grow on pacea)ers, heart#hey grow on pacea)ers, heart

valve replaceents, artifcial ;ointsvalve replaceents, artifcial ;ointsand other surgical iplants. #heand other surgical iplants. #he CDCCDC

!!enters for !isease ontrolenters for !isease ontrol

estiate that over 6/? oestiate that over 6/? o=osocoial !hospital%ac(uired=osocoial !hospital%ac(uired

inections are caused by biofls.inections are caused by biofls.


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Biofls interere in -ntibioticBiofls interere in -ntibiotic


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Biofls interere in -ntibioticBiofls interere in -ntibiotic

#herapy#herapy Bacteria growing in aBacteria growing in a

biofl are highlybiofl are highly

resistant to antibiotics,resistant to antibiotics,

up to 1,000 ties oreup to 1,000 ties ore

resistant than the saeresistant than the saebacteria not growing inbacteria not growing in

a biofl. *tandarda biofl. *tandard

antibiotic therapyantibiotic therapyisis

oten useless and theoten useless and the

only recourse ay beonly recourse ay beto reove theto reove the

containated iplant.containated iplant.

Biofl and -ntibioticBiofl and -ntibiotic


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Biofl and -ntibioticBiofl and -ntibiotic

resistanceresistance - )ey property o bio- )ey property o bio

fls is that individualfls is that individual

icroorganiss areicroorganiss are

bound together by abound together by a

polyeric substancepolyeric substancee'creted by thee'creted by the

icroorganiss.. #hisicroorganiss.. #his

protectiveprotective

encapsulation isencapsulation is

believed to play a rolebelieved to play a role

in soe antibiotic%in soe antibiotic%

resistant inection.resistant inection.

Bacterial resitance andBacterial resitance and


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Bacterial resitance andBacterial resitance and

BioflsBiofls -nother area o great iportance ro a-nother area o great iportance ro a

public health perspective is the role opublic health perspective is the role obiofls in antiicrobial%drug resistance.biofls in antiicrobial%drug resistance.Bacteria within biofls are intrinsicallyBacteria within biofls are intrinsicallyore resistant to antiicrobial agentsore resistant to antiicrobial agentsthan plan) tonic cells because o thethan plan) tonic cells because o thediinished rates o ass transport odiinished rates o ass transport oantiicrobial olecules to the bioflantiicrobial olecules to the biofl

associated cells or because biofl cellsassociated cells or because biofl cellsdiAer physiologically ro plan) tonicdiAer physiologically ro plan) toniccellscells


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Biolms in #ystic brosisBiolms in #ystic brosis

Biofls areBiofls areinvolved ininvolved in

nuerousnuerous

diseases. :n cysticdiseases. :n cystic

fbrosis patientsfbrosis patients

have 8seudoonashave 8seudoonas

inections thatinections that

oten result inoten result inantibiotic resistantantibiotic resistant

biofls.biofls.


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0ndocarditis and Biolms0ndocarditis and Biolms

icroorganiss ay attach and developicroorganiss ay attach and developbiofls on coponents o echanical heartbiofls on coponents o echanical heartvalves and surrounding tissues o the heart,valves and surrounding tissues o the heart,leading to a condition )nown as prostheticleading to a condition )nown as prosthetic

valve endocarditis. #he priary organissvalve endocarditis. #he priary organissresponsible or this condition areresponsible or this condition are ".".epidermidis, ". aureus, "treptococcusepidermidis, ". aureus, "treptococcus sppspp.,.,gra%negative bacilli, diphtheroids,gra%negative bacilli, diphtheroids,

enterococci, andenterococci, and

andidaandida

spp. #hesespp. #hese

organiss ay originate ro the s)in, otherorganiss ay originate ro the s)in, otherindwelling devices such as central venousindwelling devices such as central venouscatheters, or dental wor).catheters, or dental wor).


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0ye and Biolms0ye and Biolms

#he presence o#he presence obacterial biofls hasbacterial biofls hasbeen deonstrated onbeen deonstrated onany edical devicesany edical devicesincluding intravenousincluding intravenouscatheters, as well ascatheters, as well asaterials relevant to theaterials relevant to theeye such as contacteye such as contactlenses, scleral buc)les,lenses, scleral buc)les,suture aterial, andsuture aterial, andintraocular lenses. anyintraocular lenses. anyocular inections otenocular inections otenoccur when suchoccur when suchprosthetic devices coeprosthetic devices coein contact with or arein contact with or areiplanted in the eye.iplanted in the eye.


74/107

Biofls and 2ontact lensesBiofls and 2ontact lenses

Bacterial bioflBacterial biofloration on contactoration on contactlenses and contact lenslenses and contact lensstorage cases ay bestorage cases ay bea ris) actor in contacta ris) actor in contact

lens%associated corneallens%associated cornealinections. *tudiesinections. *tudieshave shown thathave shown thatcontaination o lenscontaination o lenscases by bacteria,cases by bacteria,ungi, and aoebae isungi, and aoebae is

coon with 0? tocoon with 0? to0? o lens wearers0? o lens wearershaving a containatedhaving a containatedlens case.lens case.

rinary catheters andrinary catheters and


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rinary catheters andrinary catheters and

BiolmsBiolms Frinary catheters are tubular late' orFrinary catheters are tubular late' or

silicone devices, which when inserted aysilicone devices, which when inserted ayreadily ac(uire biofls on the inner orreadily ac(uire biofls on the inner orouter suraces. #he organiss coonlyouter suraces. #he organiss coonly

containating these devices andcontainating these devices anddeveloping biofls aredeveloping biofls are SSepidermidis! "nterococcus #aecalis! "epidermidis! "nterococcus #aecalis! "coli! Proteus mirabilis! P aeruginosa!coli! Proteus mirabilis! P aeruginosa!$ pneumoniae$ pneumoniae,, and other gra%negativeand other gra%negative

organiss. #he longer the urinary catheterorganiss. #he longer the urinary catheterreains in place, the greater the tendencyreains in place, the greater the tendencyo these organiss to develop biofls ando these organiss to develop biofls andresult in urinary tract inections.result in urinary tract inections.

Biofls and indwelling edicalBiofls and indwelling edical


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Biofls and indwelling edicalBiofls and indwelling edical

devicesdevices Biofls on indwelling edical devices ayBiofls on indwelling edical devices ay

be coposed o gra%positive or gra%be coposed o gra%positive or gra%

negative bacteria or yeasts. Bacterianegative bacteria or yeasts. Bacteria

coonly isolated ro these devicescoonly isolated ro these devices

include theinclude the gra%positivegra%positive #nterococcus#nterococcusfaecalis,faecalis,"taphylococcus aureus,"taphylococcus aureus,

"taphylococcus epidermidis"taphylococcus epidermidis, and, and

"treptococcus"treptococcus viridiansviridians$$ and the gra%and the gra%

negativenegative #scherichia coli, %lebsiella#scherichia coli, %lebsiellapneumoniae, &roteus mirabilis,pneumoniae, &roteus mirabilis, andand

&seudomonas aeruginosa&seudomonas aeruginosa..

%ndwelling catheters and%ndwelling catheters and


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%ndwelling catheters and%ndwelling catheters and

BioflmsBioflms&& 2entral venous catheters, the reerence2entral venous catheters, the reerence

ethod or (uantifcation o biofls onethod or (uantifcation o biofls oncatheter tips is the roll%plate techni(ue, incatheter tips is the roll%plate techni(ue, inwhich the tip o the catheter is reovedwhich the tip o the catheter is reoved

and rolled over the surace o aand rolled over the surace o anonselective ediu. Luantifcation o thenonselective ediu. Luantifcation o thebiofl depends on the nuber obiofl depends on the nuber oorganiss recovered by contact with theorganiss recovered by contact with theagar surace. Biofl%associated cells on theagar surace. Biofl%associated cells on the

inner luen o the device are not detectedinner luen o the device are not detectedwith this ethod, which has low diagnosticwith this ethod, which has low diagnosticsensitivity and low predictive value orsensitivity and low predictive value orcatheter%related bacteraeia.catheter%related bacteraeia.

:ndwelling catheters and:ndwelling catheters and


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:ndwelling catheters and:ndwelling catheters and

BioflsBioflsMM

:n addition, this ethod cannot detect:n addition, this ethod cannot detectore than 1,000 colony%oring unitsore than 1,000 colony%oring units!2$F per tip. - ethod that used!2$F per tip. - ethod that used

sonication plus vorte'ing as a eanssonication plus vorte'ing as a eanso (uantiying biofls on catheter tipso (uantiying biofls on catheter tipsshowed that a level o 10N 2$F per tipshowed that a level o 10N 2$F per tipis predictive o catheter%relatedis predictive o catheter%related

septicaeiasepticaeiaMMBiolms and Device(2ssociated InfectionsBiolms and Device(2ssociated Infections

3odney M. Donlan #enters for Disease #ontrol and 4revention3odney M. Donlan #enters for Disease #ontrol and 4revention2tlanta, 5eorgia, -22tlanta, 5eorgia, -2

-ntibiotic therapy alone ay-ntibiotic therapy alone ay


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-ntibiotic therapy alone ay-ntibiotic therapy alone ay

not cure Onot cure O -ntiicrobial agents are-ntiicrobial agents are

adinistered during valveadinistered during valvereplaceent andreplaceent andwhenever the patient haswhenever the patient hasdental wor) to preventdental wor) to preventinitial attachent byinitial attachent by)illing all icroorganiss)illing all icroorganissintroduced into theintroduced into thebloodstrea.bloodstrea. 2s ith2s ithbiolms on otherbiolms on otherindelling devices,indelling devices,

relatively fe patientsrelatively fe patientscan be cured of acan be cured of abiolm infection bybiolm infection byantibiotic therapy aloneantibiotic therapy alone

Biofls a concern inBiofls a concern in


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Biofls a concern inBiofls a concern in

-ntiicrobial #herapy-ntiicrobial #herapy icrobial biofls ay pose a public healthicrobial biofls ay pose a public health

proble or persons re(uiring indwellingproble or persons re(uiring indwelling

edical devices. #he icroorganiss inedical devices. #he icroorganiss in

biofls are diPcult or ipossible to treatbiofls are diPcult or ipossible to treat

with antiicrobial agentsI detachent rowith antiicrobial agentsI detachent rothe device ay result in inection. -lthoughthe device ay result in inection. -lthough

edical devices ay diAer widely in designedical devices ay diAer widely in design

and use characteristics, specifc actorsand use characteristics, specifc actors

deterine susceptibility o a device todeterine susceptibility o a device toicrobial containation and bioflicrobial containation and biofl

oration.oration.

Biofls need higherBiofls need higher


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Biofls need higherBiofls need higher

concentration o -ntibioticsconcentration o -ntibiotics Biofls are rear)ably diPcult to treatBiofls are rear)ably diPcult to treat

with antiicrobials. -ntiicrobials aywith antiicrobials. -ntiicrobials ay

be readily inactivated or ail to penetratebe readily inactivated or ail to penetrate

into the biofl. :n addition, bacteriainto the biofl. :n addition, bacteriawithin biofls have increased !up towithin biofls have increased !up to

1000%old higher resistance to1000%old higher resistance to

antiicrobial copounds, even thoughantiicrobial copounds, even though

these sae bacteria are sensitive tothese sae bacteria are sensitive tothese agents i grown under plan) tonicthese agents i grown under plan) tonic

conditions.conditions.

Biolms help 5eneBiolms help 5ene


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Biolms help 5eneBiolms help 5ene

transfertransfer Biofls increase theBiofls increase the

opportunity or geneopportunity or gene

transertranser

between


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Biolms uorumBiolms uorum

sensingsensing 2ertain species o2ertain species o

bacteria counicatebacteria counicatewith each other withinwith each other withinthe biofl. -s theirthe biofl. -s theirdensity increases, thedensity increases, theorganiss secrete loworganiss secrete lowolecular weightolecular weightolecules that signalolecules that signalwhen the populationwhen the populationhas reached a criticalhas reached a criticalthreshold. #his process,threshold. #his process,

calledcalled /uorum/uorumsensingsensing, is responsible, is responsibleor the e'pression oor the e'pression ovirulence actors.virulence actors.

uorum sensing helps theuorum sensing helps the


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uorum sensing helps theuorum sensing helps the

survival of pathogenssurvival of pathogens

Biolms contribute for neBiolms contribute for ne


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Biolms contribute for neBiolms contribute for ne

phenotypesphenotypes Bacteria e'press new, and soetiesBacteria e'press new, and soeties

ore virulent phenotypes when growingore virulent phenotypes when growing

within a biofl. *uch phenotypes aywithin a biofl. *uch phenotypes ay

not have been detected in the pastnot have been detected in the pastbecause the organiss were grown onbecause the organiss were grown on

rich nutrient edia under plan) tonicrich nutrient edia under plan) tonic

conditions. #he growth conditions areconditions. #he growth conditions are

(uite diAerent particularly in the depths(uite diAerent particularly in the depthso biofls,o biofls,

Biolms protects fromBiolms protects from


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Biolms protects fromBiolms protects from

Immune responsesImmune responses Bacteria ebedded within biofls areBacteria ebedded within biofls are

resistant to both iunological andresistant to both iunological and

non% specifc deence echaniss onon% specifc deence echaniss o

the body. 2ontact with a solid suracethe body. 2ontact with a solid suracetriggers the e'pression o a panel otriggers the e'pression o a panel o

bacterial enzyes which catalyze thebacterial enzyes which catalyze the

oration o stic)y polysaccharides thatoration o stic)y polysaccharides that

proote colonization and protection.proote colonization and protection.

Biolms 6 4rotects fromBiolms 6 4rotects from


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Biolms 4rotects fromBiolms 4rotects from

4hagocytosis4hagocytosis

8hagocytes are unable to eAectively8hagocytes are unable to eAectivelyengul a bacteriu growing within aengul a bacteriu growing within a

cople' polysaccharide atri'cople' polysaccharide atri'

attached to a solid surace. #hisattached to a solid surace. #hiscauses the phagocyte to releasecauses the phagocyte to release

large aounts o pro%in&aatorylarge aounts o pro%in&aatory

enzyes and cyto)ines, leading toenzyes and cyto)ines, leading toin&aation and destruction oin&aation and destruction o

nearby tissues.nearby tissues.

#urrent ob8ectives on#urrent ob8ectives on


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#urrent ob8ectives on#urrent ob8ectives on

Biolm researchBiolm research ooevelopent o iproved iaging oevelopent o iproved iaging o

biofls in situIbiofls in situIooevelopent o iproved clinicallyevelopent o iproved clinically

relevant in vitro and in vivo odels orelevant in vitro and in vivo odels o

biofls under specifc in vivo conditions suchbiofls under specifc in vivo conditions suchas &ow rate, nutrient content, andas &ow rate, nutrient content, andteperatureIteperatureI ooevelopent o better probes !genetic,evelopent o better probes !genetic,etabolic, and iunological or real% tieetabolic, and iunological or real% tieanalysisIanalysisI oo*tudies o (uoru sensing


89/107

2urrent ob;ectives on Biofl2u e ob;ec es o o

researchresearch oo $urther characterization o biofl%specifc$urther characterization o biofl%specifc

gene e'pressionIgene e'pressionI oo*tudies o the e'change o genetic aterial*tudies o the e'change o genetic aterial

within bioflsIwithin bioflsI oo

*tudies o organic containants on substrata,*tudies o organic containants on substrata,and their in&uence on biofl structureIand their in&uence on biofl structureI

oo evelopentevelopent

o novel approaches to control pathogenico novel approaches to control pathogenic

bacteria by, or e'aple, devising strategiesbacteria by, or e'aple, devising strategiesto avour growth o non%pathogenicto avour growth o non%pathogenic

icroorganiss in biofl counitiesIicroorganiss in biofl counitiesI

2urrent ob;ectives on Biofl2urrent ob;ectives on Biofl


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2urrent ob;ectives on Biofl;

researchresearch oo*tudies o pathogenic*tudies o pathogenic

echaniss o icrobesechaniss o icrobes

growing in bioflsIgrowing in bioflsI

oo@lucidation o@lucidation o

echaniss oechaniss o

resistance o biofls toresistance o biofls to

antiicrobial agentsIantiicrobial agentsI

oo-tudies of-tudies of

host immunehost immune

responses, bothresponses, bothinnate and adaptiveinnate and adaptive

to biolmsto biolmsII

2urrent ob;ectives on Biofl2urrent ob;ectives on Biofl


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2urrent ob;ectives on Biofl;

researchresearch :n studies o inectious lung disease in cystic:n studies o inectious lung disease in cystic

fbrosisIfbrosisIoo*tudies on the potential o diagnostic*tudies on the potential o diagnosticprocedures such as Bronchoalveloar lavageprocedures such as Bronchoalveloar lavageand bronchoscopy to disturb local biofland bronchoscopy to disturb local biofl&ora and inoculate distant locationsI&ora and inoculate distant locationsI

ooevelopent oevelopent oatheatical odels and coputeratheatical odels and coputersiulations o bioflsIsiulations o bioflsI

oo evelopent o theevelopent o the

ethodology or the prevention and controlethodology or the prevention and controlo biofls ro catheters, water unit lines,o biofls ro catheters, water unit lines,and other clinically iportant solid suracesI.and other clinically iportant solid suracesI.

*earching or alternatives*earching or alternatives77


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*ea c g o a e a esg

#issue engineering#issue engineering Hole o biofls in ultiple pathologies and theHole o biofls in ultiple pathologies and the

diPculty in resolving these pathologies spea)sdiPculty in resolving these pathologies spea)s

to the iportance o developing eans oto the iportance o developing eans o

replacing or enhancing the therapies alreadyreplacing or enhancing the therapies already

in use. #he use o synthetic aterials in thein use. #he use o synthetic aterials in thebody ranges ro catheters to esh to stentsbody ranges ro catheters to esh to stents

to heart valves and beyond. Fntil theto heart valves and beyond. Fntil the

developent o viable and practical tissuedevelopent o viable and practical tissue

engineering, then nuber and types oengineering, then nuber and types oapplications in which synthetic aterials areapplications in which synthetic aterials are

used will continue to increase.used will continue to increase.

0 i M th d0merging Methods


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0merging Methods0merging Methods

*everal researchers*everal researchersare fnding solutionsare fnding solutions

or the cure o Bioflsor the cure o Biofls

, yet it is e'periental,, yet it is e'periental,

with advances inwith advances inolecular biologyolecular biology

better odelbetter odel

treatents can betreatents can be

identifed to reduceidentifed to reduce

the proble o Bioflthe proble o Biofl

intererence inintererence in

-ntibiotic therapy.-ntibiotic therapy.


94/107

2reated or2reated or r.#.J.Hao Qsr.#.J.Hao QsReQReQ

learning series.learning series.

@ail@ail

doctortvrao9gmail.comdoctortvrao9gmail.com
mailto:[email protected]?subject=Biofilmmailto:[email protected]?subject=Biofilmmailto:[email protected]?subject=Biofilm


95/107

@ndodontic biofls could be classifed as ollows9 1S@ndodontic biofls could be classifed as ollows9 1S:ntracanal biofls that are generally present on the:ntracanal biofls that are generally present on the

root canal dentine o an endodontically inected tooth.root canal dentine o an endodontically inected tooth.

S @'traradicular icrobial biofls that are ored onS @'traradicular icrobial biofls that are ored on

the root !ceentu surace ad;acent to the ape' othe root !ceentu surace ad;acent to the ape' o

endodontically inected teeth. 3S 8eriapical icrobialendodontically inected teeth. 3S 8eriapical icrobialbiofls that are isolated biofls ound in the periapicalbiofls that are isolated biofls ound in the periapical

region o an endodontically treated tooth. NS Bioaterialregion o an endodontically treated tooth. NS Bioaterial

centered inection that is ored when bacteria adherescentered inection that is ored when bacteria adheres

to an artifcial bioaterial surace such as root canalto an artifcial bioaterial surace such as root canal

obturating aterials, thereby oring a biofl. #heseobturating aterials, thereby oring a biofl. #hesebiofls could be intraradicular or e'traradicular,biofls could be intraradicular or e'traradicular,

depending on the apical e'tent o the obturation.3depending on the apical e'tent o the obturation.3


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@ndodontic icro&ora9@ndodontic icro&ora9 ost o the bacteria in an endodontic inection areost o the bacteria in an endodontic inection are

strict anaerobes. #he &ora is usually polyicrobial,strict anaerobes. #he &ora is usually polyicrobial,

doinated by obligate anaerobic bacteria. Gra%doinated by obligate anaerobic bacteria. Gra%

positive organiss are ound in appro'iately /?positive organiss are ound in appro'iately /?o the saplesI the ost predoinant areo the saplesI the ost predoinant are

streptococci !?, staphylococci !1/?,streptococci !?, staphylococci !1/?,

corynebacteria !10%/?, yeasts !1?, and others.corynebacteria !10%/?, yeasts !1?, and others.

#he Gra%negative bacteria !N? include#he Gra%negative bacteria !N? include

spirochetes !5%1?, neisseria !N?, bacteroidesspirochetes !5%1?, neisseria !N?, bacteroides

!?, usobacteriu !3?, pseudoonas !?,!?, usobacteriu !3?, pseudoonas !?,

colior bacteria !1?, and otherscolior bacteria !1?, and others

#ypes o @ndodontic#ypes o @ndodontic


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ypyp

:nections:nections :S :ntraradicular :nection:S :ntraradicular :nection 8riary intraradicular inections98riary intraradicular inections9

icroorganiss that initially invade and colonize theicroorganiss that initially invade and colonize the

necrotic pulp tissue cause priary intraradicularnecrotic pulp tissue cause priary intraradicular

inection. 8riary inections are characterized by ainection. 8riary inections are characterized by ai'ed consortiu coposed o 10 to 30 bacteriali'ed consortiu coposed o 10 to 30 bacterial

species and 103 to 10 bacterial cells per canal. #hespecies and 103 to 10 bacterial cells per canal. #he

involved icrobiota is conspicuously doinated byinvolved icrobiota is conspicuously doinated by

anaerobic bacteria, but soe acultative oranaerobic bacteria, but soe acultative or

icroaerophilic species can also be coonly oundicroaerophilic species can also be coonly ound

in priary intraradicular inections.Nin priary intraradicular inections.N


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*econdary :ntraradicular :nections9*econdary :ntraradicular :nections9 icroorganiss that were not present in theicroorganiss that were not present in the

priary inection but that were introducedpriary inection but that were introduced

into the root canal syste at soe tie aterinto the root canal syste at soe tie ater

proessional intervention cause secondaryproessional intervention cause secondary

intraradicular inections. #he entry can beintraradicular inections. #he entry can be

during treatent, between appointents, orduring treatent, between appointents, or

even ater root canal flling. *pecies involvedeven ater root canal flling. *pecies involved

can be oral or nonoral icroorganiss,can be oral or nonoral icroorganiss,

depending on the cause o inection.Ndepending on the cause o inection.N


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8ersistent :ntraradicular :nection9icroorganiss that can resist

intracanal antiicrobial proceduresand endure periods o nutrientdeprivation in a prepared canal causepersistent intraradicular inections.#his is also tered recurrentinection. :nvolved icroorganiss

are renants o a priary orsecondary inection. @ aecalis arepredoinant and is a persistentorganis. :t is coonly ound in ahigh percentage o root canal as asingle organis or as a a;orcoponent o the &ora. 8ersistent


100/107

::S @'traradicular :nection9icrobial invasion o the in&aedperiradicular tissue is invariably ase(uel o interradicular inection.-cute alveolar abscess is an e'apleo e'traradicular e'tension or a

se(uel to interradicular inection.*oeties e'traradicular inectioncan be independent o intraradicularinections. $or e'aple, apicalactinoycosis caused by-ctinoyces species and 8.

propionicu is a pathological diseasewhich can be treated only byperiapical surgery.


101/107

-trategies to prevent biolm formation depend on conte!t-trategies to prevent biolm formation depend on conte!t I2: :I;03-I2: :I;03-

gppgpp

Medical "small scale&Medical "small scale&

-I*< =' >I'0-I*< =' >I'0

#hemical approaches?antibiotics, biocides etc.#hemical approaches?antibiotics, biocides etc.

4hysicalapproaches?seofacousticenergyultrasoundvibration4hysicalapproaches?seofacousticenergyultrasoundvibration

-#I0:#0--#I0:#0- 4hysical approaches?se of acoustic energy, ultrasound, vibration, 4ie@o electric4hysical approaches?se of acoustic energy, ultrasound, vibration, 4ie@o electric

elements Biological approaches?>ytic bacteriophages, interference ithelements Biological approaches?>ytic bacteriophages, interference ith

Idtil"ll&Idtil"ll&

inter(bacterial signaling, interference ith genetic programs that control biolminter(bacterial signaling, interference ith genetic programs that control biolm

formationformation

Industrial "large scale& #hemical approaches?chlorine, o@one, ioni@ation, hydrogenIndustrial "large scale& #hemical approaches?chlorine, o@one, ioni@ation, hydrogen

pero!ide, various biocidespero!ide, various biocides 4hysical approaches?choice of material that inhibits attachment, vibration,4hysical approaches?choice of material that inhibits attachment, vibration,

mechanical cleaning "e.g. high pressure )ushing&, ;mechanical cleaning "e.g. high pressure )ushing&, ;

.umb.no.umb.no

Biological approaches?alteration of groth conditionsA,Biological approaches?alteration of groth conditionsA,


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ethods or analysing icrobial biofls9ethods or analysing icrobial biofls9 :-= F=:J@H*:-= F=:J@H*

ygyg

@lectron icroscopy@lectron icroscopy

*:#T C$ :$@*:#T C$ :$@

=anoscale iaging2onocal laser scanning icroscopy @pi&uorescence=anoscale iaging2onocal laser scanning icroscopy @pi&uorescence

icroscopy -toic orce icroscopyicroscopy -toic orce icroscopy

*2:@=2@**2:@=2@*

=anoscale analysis=anoscale analysis

#ip enhanced Haan spectroscopy#ip enhanced Haan spectroscopy

ass spectroscopyass spectroscopy

llthillthi icroarray analysis olecular techni(ues>hole genoe se(uencingicroarray analysis olecular techni(ues>hole genoe se(uencing

$luorescent labeling techni(ues$luorescent labeling techni(ues

@ssential )now howicrobial physiology and etabolis icrobial genetics@ssential )now howicrobial physiology and etabolis icrobial genetics


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8ossibly the frst identifcation o8ossibly the frst identifcation obiofl structures in inected rootbiofl structures in inected root

canals was carried out by =air !10.canals was carried out by =air !10.

Cn the basis o transission electronCn the basis o transission electronicroscopy !#@ he e'ained theicroscopy !#@ he e'ained the

root canal content o 31 teeth, whichroot canal content o 31 teeth, which

had gross coronal caries and to whichhad gross coronal caries and to whichthe periapical in&aatory processthe periapical in&aatory process

was attached upon e'tractionwas attached upon e'traction


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he bacterial condensations showed ahe bacterial condensations showed apalisade structure siilar to the onepalisade structure siilar to the one

or dental pla(ue on e'ternal toothor dental pla(ue on e'ternal tooth

suraces, suggesting siilarsuraces, suggesting siilarechaniss or bacterial attachentechaniss or bacterial attachent

as those or dental pla(ueas those or dental pla(ue


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olven et al. !11 noted by scanningelectron icroscopic !*@observations o the apical oinected root canals that cocci androds and


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. :n a study o cases resisting treatent, the so%. :n a study o cases resisting treatent, the so%called reractory endodontic cases, #ronstad et al.called reractory endodontic cases, #ronstad et al.

!N e'ained the suraces o the root tips reoved!N e'ained the suraces o the root tips reoved

during surgical intervention by *@. #hey notedduring surgical intervention by *@. #hey noted

that the ape' o the roots ad;acent to the apicalthat the ape' o the roots ad;acent to the apicaloraen was coated with a continuous, sooth,oraen was coated with a continuous, sooth,

structure%less layer containing a variety ostructure%less layer containing a variety o

bacterial ors. :n irregularities o the suraces andbacterial ors. :n irregularities o the suraces and

in crypts and holes, bacteria were seen heldin crypts and holes, bacteria were seen held

together by an e'tracellular aterial. #hetogether by an e'tracellular aterial. #heorganiss were identifed as cocci and rods withorganiss were identifed as cocci and rods with

soe presence o fbrillar orsoe presence o fbrillar or


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=oiri et al. ! analyzed the presence o=oiri et al. ! analyzed the presence obiofl orations on root tips o e'tractedbiofl orations on root tips o e'tracted

teeth with Rreractory periapical pathosisQteeth with Rreractory periapical pathosisQ

and gutta%percha points reoved duringand gutta%percha points reoved during

endodontic treatent by *@. Guttaperchaendodontic treatent by *@. Guttapercha

points stic)ing out through the ape' werepoints stic)ing out through the ape' were

alost copletely covered with glycocaly'%alost copletely covered with glycocaly'%

li)e structures. Bacteria, ostly flaentsli)e structures. Bacteria, ostly flaents

or long rods, were seen on the e'ternal rootor long rods, were seen on the e'ternal root

suraces in the e'tracted teethsuraces in the e'tracted teeth

biofilms-091008210814-phpapp02 imp.ppt

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