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Faculty: Dr. Alvin Fox

ENTEROBACTERIACEAE,ENTEROBACTERIACEAE,VIBRIO, CAMPYLOBACTERVIBRIO, CAMPYLOBACTER

AND HELICOBACTERAND HELICOBACTER

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Key WordsOpportunistic diseases Opportunistic diseases ShigellaShigellaDiarrheaDiarrhea Bacillary dysenteryBacillary dysenteryDiarrhea Diarrhea Shiga toxinShiga toxinUrinary tract infections Urinary tract infections Salmonella Salmonella enteritidisenteritidisLactose positive/negativeLactose positive/negative SalmonellosisSalmonellosisEnteropathogenicEnteropathogenic E. coliE. coli Salmonella Salmonella choleraecholerae--suissuisEnterotoxigenicEnterotoxigenic E. coliE. coli Salmonella Salmonella typhityphiHeat stable toxin Heat stable toxin TyphoidTyphoidHeat labile toxin Heat labile toxin ViViEnteroinvasiveEnteroinvasive E. coli E. coli Yersinia Yersinia entercoliticaentercoliticaEnterohemorrhagicEnterohemorrhagic E. coliE. coli VibrioVibrio choleraecholeraeVero toxin (ShigaVero toxin (Shiga--like)like) CholeragenCholeragen (cholera toxin)(cholera toxin)HemolysinHemolysin Campylobacter Campylobacter jejunijejunipilipili Helicobacter pyloriHelicobacter pylori

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–– septicemia, septicemia, –– pneumonia, pneumonia, –– meningitismeningitis–– urinary tract infectionsurinary tract infections

CitrobacterEnterobacterEscherichiaHafniaMorganellaProvidenciaSerratia

Opportunistic diseasesOpportunistic diseases--EnterobacteriaceaeEnterobacteriaceae

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EnterobacteriaceaeEnterobacteriaceae

• gastrointestinal diseasesgastrointestinal diseases–– Escherichia coliEscherichia coli–– SalmonellaSalmonella–– ShigellaShigella–– Yersinia Yersinia entercoliticaentercolitica

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•• HistocompatibilityHistocompatibility antigen (HLA) B27antigen (HLA) B27

– Enterobacteriaceae*Salmonella*Shigella*Yersinia

–– NotNot EnterobacteriaceaeEnterobacteriaceae**CampylobacterCampylobacter**ChlamydiaChlamydia

Reiter's syndromeReiter's syndrome

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• community acquired • otherwise healthy people

– Klebsiella pneumoniae* respiratory diseases* prominent capsule

–urinary tract infection–fecal contamination*E. coli*Proteus

–– ureaseurease (degrades urea)(degrades urea)–– alkaline urinealkaline urine

EnterobacteriaceaeEnterobacteriaceae

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EnterobacteriaceaeEnterobacteriaceae

•• gram negative facultative anaerobic rodsgram negative facultative anaerobic rods–– oxidaseoxidase negative (no negative (no cytochromecytochrome oxidaseoxidase))

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• E. coli– lactose positive – not usually identified– lactose positive sp. common, healthy intestine

• Shigella, Salmonella,Yersinia– lactose negative– identified

FecesFeces

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•• other sitesother sites– identified identified biochemicallybiochemically

EnterobacteriaceaeEnterobacteriaceae

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SerotypesSerotypes

•• reference laboratoryreference laboratory–– antigens antigens

•• O (O (lipopolysaccharidelipopolysaccharide) )

•• H (H (flagellarflagellar) )

•• K (capsular) K (capsular)

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Diarrhea and DysenteryDiarrhea and Dysentery

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Escherichia coliEscherichia coli

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• E. coli and Shigella– genetically very similar – many similarities in diseases

Escherichia coliEscherichia coli

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EnteropathogenicEnteropathogenic E. coliE. coli

destruction of surface microvilli

• fever• diarrhea• vomiting • nausea • non-bloody stools

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EnterotoxigenicEnterotoxigenic E. coliE. coli

•• diarrhea like cholera diarrhea like cholera •• milder milder •• travellerstravellers diarrheadiarrhea

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EnterotoxigenicEnterotoxigenic E. coliE. coli

•• Heat labile toxinHeat labile toxin

–– like like choleragencholeragen

–– AdenylAdenyl cyclasecyclase activated activated

–– cyclic AMP cyclic AMP

–– secretion water/ionssecretion water/ions

•• Heat stable toxinHeat stable toxin

–– GuanylateGuanylate cyclasecyclase activated activated

–– cyclic GMPcyclic GMP

–– uptake water/ionsuptake water/ions

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• Dysentery- resembles shigellosis

EnteroinvasiveEnteroinvasive E. coliE. coli (EIEC )(EIEC )

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EnterohemorrhagicEnterohemorrhagic E. coliE. coli

• Usually O157:H7

Transmission electron micrograph

Flagella

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MeatMeat• Hemorrhagic

– bloody, copious diarrhea

– few leukocytes

– afebrile

• hemolytic-uremic syndrome

– hemolytic anemia

– thrombocytopenia (low platelets)

– kidney failure

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•• Vero toxin Vero toxin –– ““shigashiga--likelike””

•• HemolysinsHemolysins

EnterohemorrhagicEnterohemorrhagic E. coliE. coli

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TreatmentTreatment --gastrointestinalgastrointestinaldiseasedisease

•• fluid replacementfluid replacement

•• antibioticsantibiotics

–– not used usually unless systemic not used usually unless systemic

––e.g. hemolytice.g. hemolytic--uremia syndromeuremia syndrome

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E. coliE. coli fimbriaefimbriae

mannosemannose

Type 1Type 1

galactosegalactose–– glycolipidsglycolipids–– glycoproteins glycoproteins

P P

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ShigellaShigella

•• S.S. flexneriflexneri, S., S. boydiiboydii, S., S. sonneisonnei, S., S.dysenteriaedysenteriae–– bacillary dysenterybacillary dysentery

–– shigellosisshigellosis•• bloody fecesbloody feces

•• intestinal painintestinal pain

•• puspus

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ShigellosisShigellosis

•• within 2within 2--3 days3 days–– epithelial cell damageepithelial cell damage

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ShigellaShigella sonneisonnei

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Shiga toxinShiga toxin

•• enterotoxicenterotoxic

•• cytotoxiccytotoxic

•• inhibits protein synthesisinhibits protein synthesis– lysing 28S rRNA

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ShigellosisShigellosis

•• man only "reservoir"man only "reservoir"

•• mostly young children mostly young children

–– fecal to oral contactfecal to oral contact

–– children to adultschildren to adults

•• transmitted by adult food handlerstransmitted by adult food handlers

–– unwashed handsunwashed hands

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Treating shigellosisTreating shigellosis

• manage dehydration

• patients respond to antibiotics– disease duration diminished

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SalmonellaSalmonella

Flagella

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SalmonellaSalmonella

•• 2000 antigenic "types2000 antigenic "types””

•• genetically single speciesgenetically single species–– S. S. entericaenterica

•• disease categorydisease category–– S. S. enteritidisenteritidis

–– many serotypesmany serotypes

–– S. S. choleraecholerae--suissuis

–– S. S. typhityphi

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SalmonellosisSalmonellosis

•• S. S. enteritidisenteritidis–– the common salmonella infectionthe common salmonella infection

–– poultry, eggspoultry, eggs–– no human reservoirno human reservoir

–– Gastroenteritis Gastroenteritis •• nausea nausea

•• vomiting vomiting

•• nonnon--bloody stoolbloody stool

•• selfself--limiting (2limiting (2 -- 5 days)5 days)

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SalmonellosisSalmonellosis

uncomplicated cases (the vast majority) antibiotic therapy not useful

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S.S. choleraecholerae--suissuis

• much less common

• septicemia

• antibiotic therapy essential

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TyphoidTyphoid•• enteric feverenteric fever

•• severest salmonella diseaseseverest salmonella disease

•• Salmonella Salmonella typhityphi

•• rare in USrare in US

•• epidemicsepidemics

–– third worldthird world

–– Europe Europe

** historical historical

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SalmonellaSalmonella typhityphi

•• human reservoirhuman reservoir–carrier state common

•• contaminated foodcontaminated food

•• water supplywater supply

•• poor sanitary conditionspoor sanitary conditions

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TyphoidTyphoid

acute phase, gastroenteritis acute phase, gastroenteritis

gall bladdergall bladder––shedding, weeksshedding, weeks

septicemiasepticemia-- occurs 10occurs 10--14 days14 days–– lasts 7 dayslasts 7 days

gastrointenteritisgastrointenteritis

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S.S. typhityphi

•• Vi (capsular) antigen Vi (capsular) antigen –– protectiveprotective

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TyphoidTyphoid --TherapyTherapy

•• AntibioticsAntibiotics

–– essentialessential

•• Vaccines Vaccines

–– ineffectiveineffective

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YersiniosisYersiniosis

• Yersinia entercolitica–gastroenteritis

– Scandinavia common

– US*colder regions

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YersiniosisYersiniosis

•• transmission transmission

–– fecal contamination, domestic animalsfecal contamination, domestic animals•• water water

•• milkmilk

–– meatmeat

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YersiniaYersinia

Diarrheafeverabdominal painantibiotic therapy recommendedoccassional bacteremia

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YersiniaYersinia --isolationisolation

cold enrichmentcold enrichment

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•• similarsimilar•• less severe diseaseless severe disease

Y. Y. pseudotuberculosispseudotuberculosis

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VibrioVibrio choleraecholerae

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Vibrios

•• Gram negative rodsGram negative rods

•• comma shapedcomma shaped

•• facultative anaerobesfacultative anaerobes

•• oxidaseoxidase positivepositive

•• simple nutritional requirementssimple nutritional requirements

•• readily cultivatedreadily cultivated

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OccurrenceOccurrence --choleracholera

• third world

• US

– uncommon

*traveler

*ingestion of sea-food

٤٧food

feces

waterwater–– freshfresh–– saltsalt

Transmission - V.V. choleraecholerae

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CholeraCholera -- attachmentattachment

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Cholera toxinCholera toxin-- CholeragenCholeragen

•• B binds toB binds to gangliosidesgangliosides

•• provides channel for Aprovides channel for A

•• A catalyses ADPA catalyses ADP--ribosylationribosylation–– regulator complexregulator complex

–– activatesactivates adenylateadenylate cyclasecyclase

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• massive secretion of ions/water into gut lumen

• dehydration and death • therapy

– fluid replacement– antibiotic therapy

• vaccination – partially effective – not generally used– international travelers

CholeraCholera --therapytherapy

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• raw sea-food• grows best in high salt • not common in US• diarrhea

VibrioVibrio parahemolyticusparahemolyticus

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CAMPYLOBACTERCAMPYLOBACTER && HELICOBACTERHELICOBACTER

•• Gram negative rodsGram negative rods•• curved or spiral curved or spiral •• genetically relatedgenetically related

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CampylobacterCampylobacter

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C.C. jejunijejuni

• infects the intestinal tract of animalsinfects the intestinal tract of animals–– cattle and sheepcattle and sheep–– major cause of abortionsmajor cause of abortions

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Transmission

• milk

• meat products

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CampylobacterCampylobacter

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IsolationIsolation -- CampylobacterCampylobacter

•• microaerophilicmicroaerophilic

•• grows best 42grows best 42ooCC

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•• diarrheadiarrhea•• malaise malaise •• feverfever•• abdominal painabdominal pain• usually self-limiting • antibiotics occassionally• bacteremia

––small minoritysmall minority

CampylobacterCampylobacter -- symptomssymptoms

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•• stomach mucosastomach mucosa

•• ulcersulcers

Helicobacter pylori

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UreaseUrease

•• Important in neutralizing stomach acidImportant in neutralizing stomach acid

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• Culture- urease NH4+ CO2

• mucosal endoscopy NH4

• radioactive CO2 breathafter feeding radioactive urea

DiagnosisDiagnosis --HelicobacterHelicobacter

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TherapyTherapy -HelicobacterHelicobacter

•• AntibioticsAntibiotics

–– cures ulcerscures ulcers

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Summary statementSummary statement

•• sanitary measures sanitary measures

–– protect the water supply protect the water supply

•• food/water borne epidemics food/water borne epidemics

–– rare US rare US

–– common third worldcommon third world

•• zoonoticzoonotic infections infections

–– contaminated animal products contaminated animal products

–– less well controlledless well controlled

–– common US and elsewherecommon US and elsewhere

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TherapyTherapy• severe diarrheasevere diarrhea

–– fluid replacement essentialfluid replacement essential

•• antibiotic therapy sometimes used in local antibiotic therapy sometimes used in local infection but always in systemic diseaseinfection but always in systemic disease