anerobic bacteria.ppt

8/17/2019 anerobic bacteria.ppt

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Anaerobic BacteriaAnaerobic Bacteria


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CategoryCategory

Spore-forming:Spore-forming:

rod, Gram (+)--- Clostridiumrod, Gram (+)--- Clostridium Nonspore-forming:Nonspore-forming:

see net slidessee net slides


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Spore-Spore-forming:forming:

rod, Gram (+)--- Clostridiumrod, Gram (+)--- Clostridium

Nonspore-forming:Nonspore-forming:

!od, Gram (+)!od, Gram (+) "ropionibacterium"ropionibacterium丙酸菌属Bi#dobacteriumBi#dobacterium

$actobacillus$actobacillus

%ubacterium%ubacterium

ActinomycesActinomyces

!od, Gram (-)!od, Gram (-) BacteroidesBacteroides

&usobacterium &usobacterium梭菌属 CampylobacterCampylobacter

Cocci, Gram (+)Cocci, Gram (+) "eptococcus"eptococcus"eptostreptococcus "eptostreptococcus

Cocci, Gram (-)Cocci, Gram (-) 'eillonella'eillonella

CategoryCategory


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Clostridium SpeciesClostridium Species

The clostridia are opportunisticThe clostridia are opportunisticpathogens. Nonetheless, they arepathogens. Nonetheless, they are

responsible for some of the deadliestresponsible for some of the deadliest

diseases includingdiseases including gas gangrene,gas gangrene,

tetanus and botulismtetanus and botulism. Less life-. Less life-threatening diseases includethreatening diseases include

pseudomembranous colitispseudomembranous colitis (PC) and(PC) and

food poisoning.food poisoning.

cause disease primarily through thecause disease primarily through the

production of numerous exotoxins.production of numerous exotoxins.

perfringens, tetani, botulinum, difficileperfringens, tetani, botulinum, difficile


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Clostridium TetaniClostridium Tetani

Pathogenesis of tetanus caused by C tetani


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General introductionGeneral introduction

C tetani C tetani is found worldwide.is found worldwide.

Ubiquitous inUbiquitous in soil soil , it is occasionally, it is occasionally

found infound in intestinal flora of humansintestinal flora of humans

and animalsand animals C.C.tetani tetani is the cause ofis the cause of tetanustetanus,or,or

lockjawlockjaw. When spores are introduced. When spores are introduced

into wounds by contaminated soil orinto wounds by contaminated soil orforeign objects such as nails or glassforeign objects such as nails or glass

splinterssplinters


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BIOCHEMICAL CHARACTERISTICSBIOCHEMICAL CHARACTERISTICS

orphologyorphology: long and slender;: long and slender;peritrichous flagella,no capsule,peritrichous flagella,no capsule,terminal located roundterminal located round

spore(drum-stick apperance), spore(drum-stick apperance),its diameter greater thanits diameter greater thanvegetative cell vegetative cell ..

CultureCulture:obligate anaerobic;:obligate anaerobic;ram!"#; swarming occures onram!"#; swarming occures onblood agar, faint hemolysis.blood agar, faint hemolysis.

!iochemical acti"ities#!iochemical acti"ities#does notdoes notferment any carbohydrate andferment any carbohydrate and

proteins.proteins. $esistance$esistance: tolerate boiling for: tolerate boiling for

$% min.ali&e se&eral ten years in$% min.ali&e se&eral ten years insoil.soil.

ClassificationClassification and 'ntigenicand 'ntigenic

(ypes:(ypes: C tetaniC tetani is the only species.is the only species.(here are no serotypes(here are no serotypes

2-5 x 0.3-0.5um2-5 x 0.3-0.5um


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PathogenicityPathogenicity

)o in&asi&eness; to*emia)o in&asi&eness; to*emia!e*ogenous infection!e*ogenous infection）） produces two e*oto*ins:produces two e*oto*ins:

tetanolysin, andtetanolysin, and

tetanospasmintetanospasmin!a kind of!a kind of

neuroto*in, to*icityneuroto*in, to*icitystrong#strong#

The actions ofThe actions of

tetanospasmintetanospasmin areare

comple* and in&ol&e threecomple* and in&ol&e threecomponents of thecomponents of the

ner&ous system:ner&ous system: centralcentral

motor controlmotor control,, autonomicautonomic

functionfunction, and the, and theneuromuscular junctionneuromuscular junction..

retrograde transportretrograde transportto !C)+#to !C)+#

delitescencedelitescence ：： a fewa few

days to se&eraldays to se&eral

weeksweeks (he two animal(he two animal

species mostspecies most

susceptible to thissusceptible to thisto*emia are horsesto*emia are horses

andand humanshumans..


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Clostridium tetani Clostridium tetani Tetanos!asminTetanos!asmin

disseminates systemicallydisseminates systemically binds to ganglioside receptorsbinds to ganglioside receptors

inhibitory neurones in CN%inhibitory neurones in CN%

glycineglycine neurotransmitterneurotransmitter

stops ner"e impulse to musclesstops ner"e impulse to muscles spastic paralysisspastic paralysis痉挛性麻痹 se"ere muscle contractions andse"ere muscle contractions and

spasmsspasms can be fatalcan be fatal


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etanospasmin etanospasmin


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Clinical Mani"estationsClinical Mani"estations

The initial symptom is cramping andThe initial symptom is cramping andt&itching of muscles around a &ound. Thet&itching of muscles around a &ound. Thepatient usually haspatient usually has no fe"erno fe"er but s&eatsbut s&eatsprofusely and begins to experience pain,profusely and begins to experience pain,especially in the area of the &ound andespecially in the area of the &ound and

around the nec' and a& musclesaround the nec' and a& muscles (trismus)(trismus).. Portions of the body may become extremelyPortions of the body may become extremely

rigid, andrigid, and opisthotonosopisthotonos角弓反张 (a spasm(a spasmin &hich the head and heels are bentin &hich the head and heels are bent

bac'&ard and the body bo&ed for&ard) isbac'&ard and the body bo&ed for&ard) iscommon.common.

Complications include fractures, bo&elComplications include fractures, bo&elimpaction, intramuscular hematoma, muscleimpaction, intramuscular hematoma, muscle

ruptures, and pulmonary, renal, and cardiacruptures, and pulmonary, renal, and cardiacproblemsproblems


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Clinical Mani"estationsClinical Mani"estations*%+%+*%+%+ CL*NCL N*+%TT*N%CL*NCL N*+%TT*N%

/enerali0ed/enerali0ed *n"ol"ement of bulbar and paraspinal*n"ol"ement of bulbar and paraspinal

muscles(trismus or loc'a&, risus sardonicus,muscles(trismus or loc'a&, risus sardonicus,difficulty s&allo&ing, irritability,difficulty s&allo&ing, irritability,

opisthotonos)1in"ol"ement of autonomicopisthotonos)1in"ol"ement of autonomic

ner"ous system(s&eating, hyper thermia,ner"ous system(s&eating, hyper thermia,

cardiac arrhythmias, fluctuations in bloodcardiac arrhythmias, fluctuations in blood

pressure)pressure)CephalicCephalic Primary infection in head,particularlyPrimary infection in head,particularly

ear1isolated or combined in"ol"ement of craniaear1isolated or combined in"ol"ement of crania

ner"es, particularly se"enth cranial ner"e1 "eryner"es, particularly se"enth cranial ner"e1 "ery

poor prognosispoor prognosis

Locali0edLocali0ed *n"ol"ement of muscles in area of primary*n"ol"ement of muscles in area of primaryinury1 infection may precede generali0edinury1 infection may precede generali0eddisease1 fa"orable prognosisdisease1 fa"orable prognosis

NeonatalNeonatal /enerali0ed disease in neonates1 infection/enerali0ed disease in neonates1 infectiontypically originates from umbilicaltypically originates from umbilical脐带

stump1"ery poor prognosis in infants &hosestump1"ery poor prognosis in infants &hosemothers are nonimmunemothers are nonimmune


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E!idemiologyE!idemiology

2 million cases of tetanus occur annually in the2 million cases of tetanus occur annually in the

&orld,&ith a mortality rate ranging from345&orld,&ith a mortality rate ranging from345to 645. !ut rare in most de"eloped countries.to 645. !ut rare in most de"eloped countries.

*n some*n some de"eloping countriesde"eloping countries, tetanus is still, tetanus is stillone of the ten leading causes of death, andone of the ten leading causes of death, and

neonatal tetanus accounts for approximatelyneonatal tetanus accounts for approximatelyone-half of the cases &orld&ide.one-half of the cases &orld&ide. *n less de"eloped countries, approximate*n less de"eloped countries, approximate

mortality rates remain 765 for neonatalmortality rates remain 765 for neonataltetanus and 645 for nonneonatal tetanus.tetanus and 645 for nonneonatal tetanus.

*n the 8nited %tates, intra"enous drug abusers*n the 8nited %tates, intra"enous drug abusersha"e become another population &ith anha"e become another population &ith anincreasing incidence of clinical tetanusincreasing incidence of clinical tetanus

*n untreated tetanus, the fatality rate is*n untreated tetanus, the fatality rate is 945945

for the ne&born andfor the ne&born and :45:45 for adults.for adults.


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ImmunityImmunity

;umoral immunity;umoral immunity(antitoxin)(antitoxin)

There is little, if any, inate immunityThere is little, if any, inate immunity

and the disease does not produceand the disease does not produceimmunity in the patient.immunity in the patient.

cti"e immunity follo&s "accinationcti"e immunity follo&s "accination

&ith tetanus&ith tetanus toxoid toxoid


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#iagnosis#iagnosis iagnosis is primarily byiagnosis is primarily by the clinicalthe clinical

symptoms (abo"e).symptoms (abo"e). The &ound may notThe &ound may notbe ob"ious.be ob"ious.

C tetani can be reco"ered from the &oundC tetani can be reco"ered from the &oundin only about one-third of the cases.in only about one-third of the cases.

*t is important for the clinician to be*t is important for the clinician to bea&are that toxigenic strains of C tetania&are that toxigenic strains of C tetanican gro& acti"ely in the &ound of ancan gro& acti"ely in the &ound of animmuni0ed person.immuni0ed person.

Numerous syndromes, includingNumerous syndromes, including rabiesrabiesand meningitis,and meningitis, ha"e symptoms similar toha"e symptoms similar tothose of tetanus and must be consideredthose of tetanus and must be consideredin the differential diagnosis.in the differential diagnosis.


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• infantinfant

• DPT (diptheria, pertussis, tetanus)DPT (diptheria, pertussis, tetanus)• tetanus toxoidtetanus toxoid

– antigenicantigenic –

no exotoxic activityno exotoxic activity

VaccinationVaccination


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ControlControl

The offending organism must beThe offending organism must beremo"ed by localremo"ed by local debridemendebridemen清创术

toxoidtoxoid TTTT1 etronida0ole (or more1 etronida0ole (or more

serious &ounds)serious &ounds)

*%*% patients may not respondpatients may not respondto prophylactic inections ofto prophylactic inections oftetanus toxoidtetanus toxoid


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C. perfringensC. perfringens

• soil, fecal contaminationsoil, fecal contamination• gas gangrenegas gangrene

– swelling of tissuesswelling of tissues – gas releasegas release

* fermentation productsfermentation products

• wound contaminationwound contamination


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ToxinsToxins

to*into*in -iological eature-iological eature (ypes of (o*ins(ypes of (o*ins

'' -- CC // 00

αα lecithinaselecithinase1 increase the1 increase the

"ascular permeability1"ascular permeability1

hemolytic1 produceshemolytic1 produces

necroti0ing acti"itynecroti0ing acti"ity

"" "" "" "" ""

ββ Necroti0ing acti"ity,Necroti0ing acti"ity,induces hypertensioninduces hypertension

by causing release ofby causing release of

catecholamines.catecholamines.

－－ "" "" －－－－

εε increase theincrease thepermeability ofpermeability of

gastrointestinal &allgastrointestinal &all

－－－－－－ "" －－

ττ Necroti0ing acti"ity1Necroti0ing acti"ity1

increase the "ascularincrease the "ascularpermeabilitypermeability

－－－－－－－－ ""


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ToxinsToxins 1any of these to*ins ha&e lethal,1any of these to*ins ha&e lethal,

necroti2ing, and hemolytic properties;necroti2ing, and hemolytic properties; (he alpha to*in produced by all types of(he alpha to*in produced by all types of C.C. perfringens, perfringens, is a lecithinase that lysesis a lecithinase that lyseserythrocytes, platelets, leukocytes, anderythrocytes, platelets, leukocytes, and

endothelial cells. 'nd its lethal action isendothelial cells. 'nd its lethal action isproportionate to the rate at which it splitsproportionate to the rate at which it splitslecithin to phosphorylcholine andlecithin to phosphorylcholine anddiglyceride.diglyceride.

(he theta to*in has similar hemolytic and(he theta to*in has similar hemolytic andnecroti2ing effects.necroti2ing effects.

/)'ase, hyaluronidase, a collagenase are/)'ase, hyaluronidase, a collagenase arealso producedalso produced


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EnterotoxinEnterotoxin 1any strains of type ' produce1any strains of type ' produce

enteroto*in, which is a heat3labile proteinenteroto*in, which is a heat3labile proteinand destroyed immediately at 4%% .and destroyed immediately at 4%% .

(rypsin treatment enhances the to*in(rypsin treatment enhances the to*inacti&ity threefold.acti&ity threefold.

(he to*in is produced primarily by type '(he to*in is produced primarily by type 'strains but also by a few type C and /strains but also by a few type C and /strains.strains.

5t disrupts ion transport in the5t disrupts ion transport in theileum!primarily# and jejunum by insertingileum!primarily# and jejunum by insertinginto the cell membrane and alteringinto the cell membrane and alteringmembrane permeability.membrane permeability.

's superantigen.'s superantigen.


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•Tissue degrading enzymesTissue degrading enzymes – lecithinase lecithinase

toxin!toxin!

– proteolytic enzymesproteolytic enzymes

– saccharolytic enzymessaccharolytic enzymes• Destruction of blood vesselsDestruction of blood vessels• Tissue necrosisTissue necrosis

• "naerobic environment created"naerobic environment created• #rganism spreads#rganism spreads

PathogenesisPathogenesis


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$ithout treatment death$ithout treatment death

occurs within % daysoccurs within % days

effective antibiotic therapyeffective antibiotic therapy debridementdebridement

anti&toxinanti&toxin amputation ' death is rareamputation ' death is rare


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Gas gangreneGas gangrene

as gangreneas gangrene is a life3threatening disease withis a life3threatening disease witha poor prognosis and often fatal outcome.a poor prognosis and often fatal outcome.

5nitial trauma to host tissue damages muscle and5nitial trauma to host tissue damages muscle and

impairs blood supply3333lack of o*ygenationimpairs blood supply3333lack of o*ygenation

5nitial symptoms5nitial symptoms :: fe&erfe&er and pain in the infectedand pain in the infectedtissue.; more local tissue necrosis and systemictissue.; more local tissue necrosis and systemicto*emia. 5nfected muscle is discolored !purpleto*emia. 5nfected muscle is discolored !purplemottling# and edematous and produces amottling# and edematous and produces a foulfoul33

smelling e*udate; gassmelling e*udate; gas bubblesbubbles form from theform from theproducts of anaerobic fermentation.products of anaerobic fermentation.


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Gas gangreneGas gangrene

's capillary permeability increases,'s capillary permeability increases,

the accumulation of fluid increases,the accumulation of fluid increases,

and &enous return e&entually isand &enous return e&entually is

curtailed.curtailed. 's more tissue becomes in&ol&ed, the's more tissue becomes in&ol&ed, the

clostridia multiply within theclostridia multiply within the

increasing area of dead tissue,increasing area of dead tissue,releasing more to*ins into the localreleasing more to*ins into the local

tissue and the systemic circulation.tissue and the systemic circulation.


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Food poisoning Food poisoning

+nterotoxin producing strains+nterotoxin producing strains..

(hese bacteria are found in(hese bacteria are found in

mammalianmammalian faeces and soilfaeces and soil..

+mall numbers of the bacteria may+mall numbers of the bacteria may

also be found in foods and they mayalso be found in foods and they may

propagate rapidly to dangerouspropagate rapidly to dangerous

concentrations if the food isconcentrations if the food isimproperly stored and handled.improperly stored and handled.


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Food poisoning Food poisoning

more than 4%more than 4%66 &egetati&e cells are&egetati&e cells are

ingested and sporulate in the gut, theingested and sporulate in the gut, the

to*ins can act rapidly in the body,to*ins can act rapidly in the body,

causing se&ere diarrhea in $346 hours,causing se&ere diarrhea in $346 hours,dysentery, gangrene, muscle infectionsdysentery, gangrene, muscle infections

(he action of(he action of C. perfringensC. perfringens enteroto*inenteroto*in

in&ol&es marked hypersecretion in thein&ol&es marked hypersecretion in the

jejunum and ileum, with loss of fluids jejunum and ileum, with loss of fluids

and electrolytes in diarrhea.and electrolytes in diarrhea.


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Cellulitis, FasciitisCellulitis, Fasciitis

Cellulitis, asciitisCellulitis, asciitis asciitis : a rapidly progressi&e,asciitis : a rapidly progressi&e,

destructi&e process in which the organismsdestructi&e process in which the organisms

spread through fascial plan es.spread through fascial plan es. asciitis causes suppuration and theasciitis causes suppuration and the

formation of gasformation of gas

'bsense of muscle in&ol&ement'bsense of muscle in&ol&ement rapidityrapidity


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)ecroti2ing 0nteritis)ecroti2ing 0nteritis 7are, acute necroti2ing process in the7are, acute necroti2ing process in the jejunum jejunum

'bdominal pain, bloody diarrhea, shock, and'bdominal pain, bloody diarrhea, shock, and

peritonitisperitonitis

1ortality: 8%91ortality: 8%9

-eta3to*in3producing-eta3to*in3producing C. perfringensC. perfringens type Ctype C

+epticemia+epticemia


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Who is at risk?Who is at risk?

+urgical patients+urgical patients; patient after; patient after

trauma with soil contamination.trauma with soil contamination.

eople who ingest contaminatedeople who ingest contaminated

meat productsmeat products !without proper!without proper

refrigeration or reheating torefrigeration or reheating to

inacti&ate endoto*in#inacti&ate endoto*in#


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EpidemiologyEpidemiology

C. perfringensC. perfringens type ':type ': the intestinalthe intestinal

tract of humans and animals, soil andtract of humans and animals, soil and

water contaminated with feces. formswater contaminated with feces. forms

spores under ad&erse en&ironmentalspores under ad&erse en&ironmentalconditions and can sur&i&e forconditions and can sur&i&e for

prolonged periods.prolonged periods.

(ype - to 0 strains(ype - to 0 strains coloni2e thecoloni2e theintestinal tract of animals andintestinal tract of animals and

occasionally humans.occasionally humans.


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EpidemiologyEpidemiology

(ype '(ype ': gas gangrene, soft tissue: gas gangrene, soft tissue

infections and food poisoninginfections and food poisoning

(ype C(ype C: enteritis; necroticans: enteritis; necroticans


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• lecithinase productionlecithinase production

aboratory identification

#ou$le Hemol sis Circles#ou$le Hemol sis Circles


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C. botulinumC. botulinum


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Biological %eaturesBiological %eatures

naerobicnaerobic /ram-positi"e/ram-positi"e rod-shapedrod-shaped

sporeformersporeformer produces a protein neurotoxic.produces a protein neurotoxic. soil, sediments of la'es, ponds,soil, sediments of la'es, ponds,

decaying "egetation.decaying "egetation.

intestinal tracts of birds, mammalsintestinal tracts of birds, mammalsand fish.and fish.


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---A, B, C1, D, E, F, and G.

---type A. 6!---"ot all produce to#in.

---C and D not

---G plas$id encoded.

#i&ision#i&ision


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---spores heat resistant.

cannin%.

anaero&ic en'iron$ent

---Botulis$

eatin% uncoo(ed )oods

spores

---G, duodenu$, &lood strea$,

neuro$uscular synapses.

TransmissionTransmission


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---&acterial protease

---li%ht chain,A,+ (Da

hea'y chain,1(Da.

---disul)ide &ond.

---A potent to#in

'irulence "actors'irulence "actors


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Botulinum to(inBotulinum to(in

binds peripheral ner"e receptorsbinds peripheral ner"e receptors

acetylcholine neurotransmitteracetylcholine neurotransmitter

inhibits ner"e impulsesinhibits ner"e impulses flaccid paralysisflaccid paralysis

deathdeath

respiratoryrespiratory cardiac failurecardiac failure


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Botulinum to(inBotulinum to(in

!ioterrorism!ioterrorism

not an infectionnot an infection

resembles a chemical attac'resembles a chemical attac'

4% ng can kill a normal adult4% ng can kill a normal adult


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---/ )ood&orne, in)ant, 0ound, undeter$ined.

---Certain )oods 0ound not.

---oodborne botulism, consu$ption.---*nfant botulism, 126, under 1$.

---in%estion, coloni3e and produce to#in in the

intestinal tract o) in)ants.

honey.---increased.

---internationally reco%ni3ed.

E!idemiologyE!idemiology


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---14-56 hours/

---0ea(ness, di33iness,dryness o) the $outh.

---"ausea,'o$itin%.---"eurolo%ic )eatures/ &lurred 'ision,

ina&ility to s0allo0, di))iculty in speech,

descendin% 0ea(ness o) s(eletal $uscles,

respiratory paralysis.

Clinical syndromesClinical syndromes


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BotulismBotulism))肉毒中毒肉毒中毒 **

food poisoningfood poisoning

rarerare

fatalfatal

germination of sporegermination of spore inade


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In"ection +ithIn"ection +ith C. botulinumC. botulinum

Neonatal botulismNeonatal botulism

uncommonuncommon

the predominant form ofthe predominant form of

botulismbotulism

coloni0ation occurscoloni0ation occurs

no normal flora to competeno normal flora to compete unli'e adultunli'e adult


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,ounds,ounds

extremely rareextremely rare

an infectionan infection


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ImmunityImmunity

333333specifically neutrali2ed,specifically neutrali2ed, antito*inantito*in..

333to*oided, make good antigens.333to*oided, make good antigens.

333does not de&elop, amount to*ic.333does not de&elop, amount to*ic.

3337epeated occurrence.3337epeated occurrence.

333nce bound, unaffected by antito*in.333nce bound, unaffected by antito*in.333circulating to*in ,neutrali2ed , injection333circulating to*in ,neutrali2ed , injection

of antito*in.of antito*in.

333treated immediately with antiserum.333treated immediately with antiserum.

333333multi&alentmulti&alentto*oid,unjustified,infrequency.to*oid,unjustified,infrequency.e*perimental &accine.e*perimental &accine.


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#iagnosis#iagnosis

---&y clinical sy$pto$s alone

---di))erentiation di))icult.

--- most direct and effective+ seru$ or)eces.

---$ost sensiti'e and 0idely used/

$ouse neutrali3ation test. 4h.

Culturin% o) speci$ens +-2d.


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TreatmentTreatment

5ndi&iduals known to ha&e ingested food5ndi&iduals known to ha&e ingested food

with botulism should be treatedwith botulism should be treatedimmediately with antiserum.immediately with antiserum. antibiotic therapy (if infectionantibiotic therapy (if infection))


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Pre&entionPre&ention

333proper food handling and preparation.333proper food handling and preparation.

333 spores sur&i&e boiling !4%% degrees333 spores sur&i&e boiling !4%% degrees

at 4 atm# 4h.at 4 atm# 4h.333to*in heat3labile, boiling or intense333to*in heat3labile, boiling or intense

heating, inacti&ate the to*in.heating, inacti&ate the to*in.

333333bulge, gas, spoiledbulge, gas, spoiled..

C diffi ilC difficile


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C. difficileC. difficile

• "fter antibiotic use"fter antibiotic use• *ntestinal normal flora &&greatly decreased*ntestinal normal flora &&greatly decreased

• olonization occursolonization occurs• -nterotoxin secreted-nterotoxin secreted

• Pseudomembanous colitisPseudomembanous colitis

Pseudomembranous ColitisPseudomembranous Colitis


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Pseudomembranous ColitisPseudomembranous Colitis

Pseudomembranous colitis (PC) resultsPseudomembranous colitis (PC) resultspredominantly as a conse-::5.


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Thera!yThera!y

iscontinuation of initial antibioticiscontinuation of initial antibiotic

(e.g. ampicillin)(e.g. ampicillin)

%pecific antibiotic therapy (e.g.%pecific antibiotic therapy (e.g.

"ancomycin)"ancomycin)


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• no oxidative phosphorylationno oxidative phosphorylation• fermentationfermentation• .illed by oxygen.illed by oxygen

• lac. certain enzymeslac. certain enzymes

– superoxide dismutasesuperoxide dismutase

* ##%%&&/%0/%0// 0 0%%##%%

– catalasecatalase

* 00%%##%% 0 0%%1 / #1 / #%% – peroxidaseperoxidase

* 00%%##%% 0 0%%11 23"D to 3"D023"D to 3"D0

O$ligateO$ligate )strict*)strict* anaero$esanaero$es


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Strict anaero$e in"ectiousStrict anaero$e in"ectious

diseasedisease

%ites throughout body%ites throughout body uscle, cutaneous?sub-cutaneoususcle, cutaneous?sub-cutaneous

necrosisnecrosis

bscessesbscesses


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Bacterial Flora of the BodyBacterial Flora of the Body

+ite+ite (otal -acteria(otal -acteria 7atio7atio

!per=ml or gm#!per=ml or gm# 'naerobes:'erobes'naerobes:'erobes

Upper 'irwayUpper 'irway

)asal Washings)asal Washings 4%4%>>34%34%?? >38:4>38:4

+ali&a+ali&a 4%4%6634%34%@@ 4:44:4

(ooth +urface(ooth +urface 4%4%4%4%34%34%4444 4:44:4

ingi&al Cre&iceingi&al Cre&ice 4%4%444434%34%4A4A 4%%%:44%%%:4

astrointestinal (ractastrointestinal (ract

+tomach+tomach 4%4%AA34%34%88 4:44:4

+mall -owel+mall -owel 4%4%AA34%34%?? 4:44:4

5leum5leum 4%4%??34%34%BB 4:44:4

ColonColon 4%4%444434%34%4A4A 4%%%:44%%%:4

emale enital (ractemale enital (ract

0ndocer&i*0ndocer&i* 4%4%6634%34%@@ >38:4>38:4

38:4

P bl i id tifi ti fP bl i id tifi ti f


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Problems in identification ofProblems in identification of

anaerobic infectionsanaerobic infections

• air in sample (sampling, transportation)air in sample (sampling, transportation) –

no growthno growth

• identification ta.es several days or longeridentification ta.es several days or longer – limiting usefulnesslimiting usefulness

• often derived from normal floraoften derived from normal flora – sample contamination can confusesample contamination can confuse

Vi l F tVi l F t


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Virulence FactorsVirulence Factors

4.4. 'nti3phagocytic capsule'nti3phagocytic capsule 'lso promote abscess formation'lso promote abscess formation

A.A. (issue destructi&e en2ymes(issue destructi&e en2ymes B. fragilisB. fragilis produces &ariety of en2ymesproduces &ariety of en2ymes

!lipases, proteases, collagenases# that!lipases, proteases, collagenases# thatdestroy tissuedestroy tissue 'bscess ormation'bscess ormation

>.>. -eta3lactamase production-eta3lactamase production B. fragilisB. fragilis protect themsel&es and other protect themsel&es and other

species in mi*ed infectionsspecies in mi*ed infections?.?. +upero*ide dismutase production+upero*ide dismutase production

rotects bacteria from to*ic rotects bacteria from to*ic AA radicals asradicals asthey mo&e out of usual nichethey mo&e out of usual niche


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Characteristics of naero!ic "nfectionsCharacteristics of naero!ic "nfections

2.2. ost pathogenic anaerobes areost pathogenic anaerobes are

usually commensalsusually commensals

riginate from ourriginate from our own floraown flora

3.3. Predisposing ConditionsPredisposing Conditions -reeches in the mucocutaneous barrier-reeches in the mucocutaneous barrier

displace normal floradisplace normal flora

Compromised &ascular supplyCompromised &ascular supply

(rauma with tissue destruction(rauma with tissue destruction

'ntecedent infection'ntecedent infection

Characteristics o" Anaero$icCharacteristics o" Anaero$ic


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Characteristics o" Anaero$ic

In"ectionsIn"ections

>.>. Complex loraComplex lora 1ultiple species1ultiple species 'bdominal 5nfection'bdominal 5nfection '&g'&g

of 8 speciesof 8 species > anaerobic> anaerobic

A aerobicA aerobic Dess comple* then nl floraDess comple* then nl flora

ecal flora ?%% differentecal flora ?%% differentspeciesspecies (hose predominant in stool(hose predominant in stool

are not infecting speciesare not infecting species


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Clues to Anaero$ic In"ectionClues to Anaero$ic In"ection

2.2. *nfections in continuity to mucosal*nfections in continuity to mucosalsurfacessurfaces

3.3. *nfections &ith tissue necrosis and*nfections &ith tissue necrosis andabscess formationabscess formation

A.A. Putrid odorPutrid odor:.:. /as in tissues/as in tissues

6.6. Polymicrobial floraPolymicrobial flora

B.B. ailure to gro& in the labailure to gro& in the lab

!*C;+*CL *T%!*C;+*CL *T% e.g. P* %D%T+e.g. P* %D%T+

/% C;$T/$P;D/% C;$T/$P;D "olatile fermentation products"olatile fermentation products


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Bacteroides fragilisBacteroides fragilis

• 4a5or disease causing strict anaerobic4a5or disease causing strict anaerobicafter abdominal surgeryafter abdominal surgery

non&spore&formernon&spore&former

• Prominent capsuleProminent capsule – anti&phagocyticanti&phagocytic

– abscess formationabscess formation

• -ndotoxin-ndotoxin – low toxicitylow toxicity

– structure different than otherstructure different than other

lipolysaccharidelipolysaccharide


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•

Enterobacteriaceae Enterobacteriaceae (facultative anaerobes)(facultative anaerobes)

– commonly cause diseasecommonly cause disease – low numbers gut floralow numbers gut flora

• 6trict anaerobes6trict anaerobes – much less commonly cause diseasemuch less commonly cause disease

– high numbers gut florahigh numbers gut flora .

anerobic bacteria.ppt

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