1

04/21/23

EntericsEnterics

Filename:Filename: Enterics.ppt Enterics.ppt

2

04/21/23

Gram Negative RodsGram Negative Rods

3

04/21/23

Cardiobacterium hominis:Cardiobacterium hominis:

long filaments, pleomorphic / tear droplong filaments, pleomorphic / tear drop Gentian violet may be retained in ends, Gentian violet may be retained in ends,

sometimes in the middlesometimes in the middle Facultatively anaerobic -- CO2 requiredFacultatively anaerobic -- CO2 required Strong fermentative reactions (no gas)Strong fermentative reactions (no gas) oxidase +catalase +oxidase +catalase + No growth on MacConkey, not hemolyticNo growth on MacConkey, not hemolytic

4

04/21/23

C.hominis cont’d:C.hominis cont’d:

Found in nasal floraFound in nasal flora Associated with dental diseaseAssociated with dental disease -enter the blood stream and adhere to -enter the blood stream and adhere to

damaged heart tissuedamaged heart tissue causes endocarditiscauses endocarditis -thick polar caps of tufted material-thick polar caps of tufted material

5

04/21/23

Comparison of Gm Neg rodsComparison of Gm Neg rods

oxidase catalase indole ferment. NOoxidase catalase indole ferment. NO33reduc.reduc.

C.hominis + - + + -C.hominis + - + + - H.aphrophilus ? - - + +H.aphrophilus ? - - + + Actinobacillus ? + - + +Actinobacillus ? + - + + Pasteurella + + most + + +Pasteurella + + most + + + Capnocytophaga - - - + most +Capnocytophaga - - - + most + Eikenella + - - - + Eikenella + - - - +

corrodens corrodens

6

04/21/23

Actinomyces comitansActinomyces comitans

Should be differentiated from KingellaShould be differentiated from Kingella Prevented by good oral hygienePrevented by good oral hygiene Prophylaxis before dental manipulationsProphylaxis before dental manipulations

7

04/21/23

EikenellaEikenella

facultative anaerobic gram negative rodfacultative anaerobic gram negative rod E.corrodens -- pits agar (less that 50%)E.corrodens -- pits agar (less that 50%) normal flora: opportunistic pathogennormal flora: opportunistic pathogen immunocompromisedimmunocompromised slow growingslow growing

8

04/21/23

Eikenella corrodensEikenella corrodens

SourceSource Human bitesHuman bites fist fights. fist fights.

Usually untreatedUsually untreated

ComplicationsComplications septic arthritisseptic arthritis osteomyelitisosteomyelitis meningitismeningitis brain abscessesbrain abscesses pneumoniapneumonia lung abscesseslung abscesses endocarditisendocarditis

9

04/21/23

Calymmatobacterium granulomatisCalymmatobacterium granulomatis

Pleomorphic rods, rounded ends, singles or in Pleomorphic rods, rounded ends, singles or in clusters.clusters.

Single or bipolar condensation of chromatin.Single or bipolar condensation of chromatin. Exudate from infected tissues -- use Wrights or Exudate from infected tissues -- use Wrights or

GiemsaGiemsa stain - characteristic.stain - characteristic. Intracellular organisms in the cytoplasm of largeIntracellular organisms in the cytoplasm of large mononuclear phagocytes.mononuclear phagocytes. Capsule prominent.Capsule prominent.

10

04/21/23

C. granulomatisC. granulomatis

C. (Donovania) granulomatisC. (Donovania) granulomatis Disease: granuloma inguinaleDisease: granuloma inguinale Bug: resides in the gut flora. Enters genitals by Bug: resides in the gut flora. Enters genitals by autoinoculation or sexual intercourse.autoinoculation or sexual intercourse. Penetrate skin and induce an inflammatory reaction.Penetrate skin and induce an inflammatory reaction. Tissue destroyedTissue destroyed Antibodies produced. Cell mediated defenseAntibodies produced. Cell mediated defense mechanisms -- important in recovery. This ismechanisms -- important in recovery. This is the granulomatous reaction.the granulomatous reaction.

11

04/21/23

FlavobacteriumFlavobacterium

Aerobic gram negative rodAerobic gram negative rod most important:most important: Flavobacterium meningosepticumFlavobacterium meningosepticum found in water, soil, moist reservoirs in the hospitalfound in water, soil, moist reservoirs in the hospital Not normal flora of humansNot normal flora of humans -opportunists-opportunists Diseases:Diseases: 1/ meningitis1/ meningitis 2/ septicemia2/ septicemia Resistant to many antibiotics.Resistant to many antibiotics. Most have a yellow pigment.Most have a yellow pigment. Grow on ordinary medium.Grow on ordinary medium.

12

04/21/23

S. moniliformisS. moniliformis

Streptobacillus moniliformisStreptobacillus moniliformis Causes rat bite fever.Causes rat bite fever. Found in rats worldwide.Found in rats worldwide. Transmission: rat bite, consumption of contaminatedTransmission: rat bite, consumption of contaminated liquid or food.liquid or food. Acute onset: high fever, chills, headache, myalgias,Acute onset: high fever, chills, headache, myalgias, arthritis. Can reoccur.arthritis. Can reoccur. 10% mortality if untreated -- penicillin.10% mortality if untreated -- penicillin. Culture: serologyCulture: serology Kits available -- antisera and specific antigenKits available -- antisera and specific antigen Spirillum minor - spiral shaped, can’t be culturedSpirillum minor - spiral shaped, can’t be cultured Found worldwide, primarily AsiaFound worldwide, primarily Asia

13

04/21/23

EntericsEnterics

14

04/21/23

EdwardsiellaEdwardsiella EwingellaEwingella HafniaHafnia SerratiaSerratia SalmonellaSalmonella ShigellaShigella YersiniaYersinia

EnterobacteriaceaeEnterobacteriaceae

EscherichiaEscherichia EnterobacterEnterobacter KlebsiellaKlebsiella CitrobacterCitrobacter KluyveraKluyvera ProteusProteus ProvidenciaProvidencia MorganellaMorganella

15

04/21/23

EnterobacteriaceaeEnterobacteriaceae

Virulence FactorsVirulence Factors cell wall is an important virulence factorcell wall is an important virulence factor Endotoxin or lipopolysaccharide composed Endotoxin or lipopolysaccharide composed

of:of: O polysaccharideO polysaccharide polysaccharide corepolysaccharide core

lipid A - which form repeating structural unitslipid A - which form repeating structural units

16

04/21/23

EndotoxinEndotoxin

feverfever leucopenia: leucocytosisleucopenia: leucocytosis activation of complementactivation of complement thrombocytopenia thrombocytopenia can lead to shock and deathcan lead to shock and death

17

04/21/23

Endotoxins: Pyrogenic EffectsEndotoxins: Pyrogenic Effects

Pyrogenic - fever producingPyrogenic - fever producingpresent in virtually every biologic assay present in virtually every biologic assay

system ever examinedsystem ever examinedorganism present in water systemsorganism present in water systems Heat stabileHeat stabile

18

04/21/23

Enteric Antigenic Phase Variation:Enteric Antigenic Phase Variation:

Antigens: K-capsular & H-flagellarAntigens: K-capsular & H-flagellar Exhibit phase variation expressed under Exhibit phase variation expressed under

certain conditions.certain conditions.

19

04/21/23

EnterotoxinsEnterotoxins

Heat stabileHeat stabile E.coli, E.coli, YersiniaYersinia Enterocolitica Enterocolitica Citrobacter freundiiCitrobacter freundii

Heat labileHeat labile Shiga Type Shiga Type Cholera Type Cholera Type

20

04/21/23

Shiga Type EnterotoxinsShiga Type Enterotoxins

VerotoxinVerotoxin

E. E. colicoli ShigatoxinShigatoxin

ShigellaShigella

21

04/21/23

Cholera Type EnterotoxinsCholera Type Enterotoxins

cholerae typecholerae type V.cholerae is not in EnterobacteriaceaeV.cholerae is not in Enterobacteriaceae

E. coli, Salmonella, KlebsiellaE. coli, Salmonella, Klebsiella A & B ToxinsA & B Toxins

22

04/21/23

Community acquired infectionsCommunity acquired infections

E. coli is major cause of urinary tract E. coli is major cause of urinary tract infectionsinfections

also Proteus, Klebsiella, & Enterobacter sp.also Proteus, Klebsiella, & Enterobacter sp. Proteus mirabilis is the major cause of Proteus mirabilis is the major cause of

infection related kidney stonesinfection related kidney stones Klebsiella pneumoniae severe pneumoniaKlebsiella pneumoniae severe pneumonia

23

04/21/23

Nosocomial InfectionsNosocomial Infections

45% of nosocomial Infections in the USA 45% of nosocomial Infections in the USA are caused by the Enterobacteriaceaeare caused by the Enterobacteriaceae Escherichia, Klebsiella, Enterobacter, Serratia, Escherichia, Klebsiella, Enterobacter, Serratia,

Citrobacter Proteus, ProvidenciaCitrobacter Proteus, Providencia Gram negative rods: all found in the Gram negative rods: all found in the

indigenous flora most frequently in the indigenous flora most frequently in the intestineintestine

E. coli is numero uno

24

04/21/23

Nosocomial InfectionsSites of primary infectionNosocomial Infections

Sites of primary infection

urinary tracturinary tract lower respiratory tractlower respiratory tract surgical woundssurgical wounds blood streamblood stream skinskin

25

04/21/23

Endotoxins : StructureEndotoxins : Structure

Toxic liposaccharide of outer membrane of Toxic liposaccharide of outer membrane of Gram negative bacteria. Released on Gram negative bacteria. Released on destruction of the celldestruction of the cell

O side chains ---O side chains --- CoreCore ------ Lipid ALipid A

oligosaccharides oligosaccharides polysaccharide polysaccharide

26

04/21/23

Escherichia coliEscherichia coli

27

04/21/23

E. coli: DiseasesE. coli: Diseases

GastorenteritisGastorenteritis SepticemiaSepticemia Urinary Tract InfectionUrinary Tract Infection Neonatal menigitis Neonatal menigitis

28

04/21/23

E. coli: SepticemiaE. coli: Septicemia

Intestinal perforation and disseminated Intestinal perforation and disseminated urinary tract infections are the major cause urinary tract infections are the major cause of septicemia.of septicemia.

29

04/21/23

E. coli: Urinary Tract InfectionE. coli: Urinary Tract Infection

serotypes O4, O6, O75serotypes O4, O6, O75

30

04/21/23

E. coli: VirulenceE. coli: Virulence

resist killing in serumresist killing in serum produce hemolysinsproduce hemolysins adhere to epithelial cells adhere to epithelial cells

31

04/21/23

E. coli: AntigensE. coli: Antigens

Antigens O, H, and K.Antigens O, H, and K. certain serotypes are associated with certain serotypes are associated with

specific diseasesspecific diseases

32

04/21/23

AdhesionAdhesion

Most Enterobacteriaceae have FimbriaeMost Enterobacteriaceae have Fimbriae P fimbriae: E. coli - agglutinate human RBC P fimbriae: E. coli - agglutinate human RBC

with P group antigenwith P group antigen uropathogenic E. coliuropathogenic E. coli S fimbriae: bind to sialyl galactosides on human S fimbriae: bind to sialyl galactosides on human

erythrocyteserythrocytes E. coli that cause neonatal sepsis and meningitisE. coli that cause neonatal sepsis and meningitis

33

04/21/23

ExotoxinsExotoxins

Proteins, most potent by unit weight, heat-Proteins, most potent by unit weight, heat-labile generally. labile generally.

Gram positive and Gram positive and Gram negative Gram negative organismsorganisms

Specific immune effects - antitoxinsSpecific immune effects - antitoxins Specific cellular effectsSpecific cellular effects

34

04/21/23

E coli: Neonatal meningitisE coli: Neonatal meningitis

rare in North Americarare in North America acquired in birth canalacquired in birth canal virulence associated with K antigen virulence associated with K antigen

(capsular)(capsular)

35

04/21/23

E.coli: GastroenteritisE.coli: Gastroenteritis

Small IntestineSmall Intestineenterotoxigenicenterotoxigenicenteropathogenicenteropathogenicenteroaggregativeenteroaggregative

Large IntestineLarge Intestineenteroinvasiveenteroinvasiveenterohemorrhagicenterohemorrhagic

36

04/21/23

E coli: Small intestineE coli: Small intestine

EnterotoxigenicEnterotoxigenic Traveler’s DiarrheaTraveler’s Diarrhea Infant DiarrheaInfant Diarrhea

EnteropathogenicEnteropathogenic Infant: non-bloody stoolsInfant: non-bloody stools

EnteroaggregativeEnteroaggregative Infant: persistant and may have blood in stoolInfant: persistant and may have blood in stool

37

04/21/23

E.coli: Large IntestineE.coli: Large Intestine

EnteroinvasiveEnteroinvasive watery, then dysentery-likewatery, then dysentery-like

EnterohemorrhagicEnterohemorrhagic hemorrhagic colitishemorrhagic colitis

38

04/21/23

Escherichia coliEscherichia coli

common in large numbers in intestine of common in large numbers in intestine of mammals and many other warm blooded mammals and many other warm blooded animalsanimals

39

04/21/23

E.coli: EpidemiologyE.coli: Epidemiology

North America & Western North America & Western EuropeEurope

most commonly most commonly associated with associated with endogenous infections endogenous infections (urinary tract infections (urinary tract infections most frequent)most frequent)

Gastroenteritis not as Gastroenteritis not as common as endogenous common as endogenous diseasesdiseases

Countries with poor Countries with poor hygienehygiene

bacterial sepsisbacterial sepsis neonatal meningitisneonatal meningitis gastroenteritisgastroenteritis

40

04/21/23

E. Coli: PathogenicityE. Coli: Pathogenicity

EnteropathogenicEnteropathogenic EnterohemorrhagicEnterohemorrhagic

41

04/21/23

Enteropathogenic E.coliEnteropathogenic E.coli

Adhere to cells of small intestine. Also Adhere to cells of small intestine. Also called enteroadherent. One of the adherence called enteroadherent. One of the adherence factors is plasmid mediated.factors is plasmid mediated.

42

04/21/23

Enterohemorrhagic E coliEnterohemorrhagic E coli

hemorrhagic Gastroenteritishemorrhagic Gastroenteritis hemolytic Uuremic Syndromehemolytic Uuremic Syndrome

43

04/21/23

Hemorrhagic gastroenteritisHemorrhagic gastroenteritis

Shiga-like toxin : half of the E. coli that Shiga-like toxin : half of the E. coli that cause the diseases are serotype 0157:H7.cause the diseases are serotype 0157:H7.

Hemorrhagic gastroenteritis: mild to severe, Hemorrhagic gastroenteritis: mild to severe, mostly in children < 5, undercooked ground mostly in children < 5, undercooked ground beef and unpasteurized milk.beef and unpasteurized milk.

44

04/21/23

Hemolytic uremic syndrome: Hemolytic uremic syndrome:

acute renal failure, thrombocytopenia, acute renal failure, thrombocytopenia, microangiopathic (small blood vessels), microangiopathic (small blood vessels), hemolytic anemia. Drop in blood cells due hemolytic anemia. Drop in blood cells due to hemolysis of red cells in small blood to hemolysis of red cells in small blood vessels. vessels.

45

04/21/23

The EndThe End

46

04/21/23

Short AnswersShort Answers

Construct a table of the virulence factors Construct a table of the virulence factors associated with ??? and the biological associated with ??? and the biological activity of eachactivity of each

Use a series of no more than four diagrams Use a series of no more than four diagrams to describe the mechanism of ??? activityto describe the mechanism of ??? activity

Describe the clinical manifestions ???Describe the clinical manifestions ??? Construct a table listing the common ??? Construct a table listing the common ???

species and the associated human diseases.species and the associated human diseases.