Family
Family
Enterobacteriaceae
Enterobacteriaceae
PART I
PART I
Genera:
Genera:
Escherichia
Escherichia
,
,
Klebsiella
Klebsiella
,
,
Enterobacter
Enterobacter
Family
Family
Enterobacteriaceae
Enterobacteriaceae
PART I
PART I
Genera:
Genera:
Escherichia
Escherichia
,
,
Klebsiella
Klebsiella
,
,
Enterobacter
Enterobacter
General properties of
General properties of
Enterobacteriaceae
Enterobacteriaceae
Gram-negative rods
Gram-negative rods
Non-spore-forming
Non-spore-forming
Peritrichous flagellae
Peritrichous flagellae
(motility) (exceptions!)
(motility) (exceptions!)
Capsules can be
Capsules can be
Facultative anaerobes or
Facultative anaerobes or
aerobes
aerobes
Grow in simple media
Grow in simple media
Ferment glucose and
Ferment glucose and
produce acid
produce acid
Nitrates are reduced to
Nitrates are reduced to
nitrites
nitrites
Oxidase-negative, catalase-
Oxidase-negative, catalase-
positive (exception!)
positive (exception!)
Enterobacteriaceae
Enterobacteriaceae
Lactos
e +
Lactose
-
Flagell
a +
Flagell
a -
Flagell
a +
Flagell
a -
Escherich
ia
Enterobac
ter
Citrobact
er
Serratia
Klebsiel
la
Salmonella
Proteus
Providenci
a
Hafnia
Edwarsiell
a
Shigell
a
Enterobacteriaceae
Enterobacteriaceae
Determinants of
Determinants of
pathogenicity
pathogenicity
Major antigens
Major antigens
K/Vi antigens
K/Vi antigens
(capsular)
(capsular)
H antigens
H antigens
(flagellar)
(flagellar)
O antigens
O antigens
(somatic, in LPS)
(somatic, in LPS)
Virulence factors
Virulence factors
Endotoxin (LPS)
Endotoxin (LPS)
Exotoxins
Exotoxins
Adhesion/colonizati
Adhesion/colonizati
on factors
on factors
(fimbriae)
(fimbriae)
Capsules
Capsules
Endotoxin
Endotoxin
(LPS – lipopolysaccharide)
(LPS – lipopolysaccharide)
Polysaccharide core
Polysaccharide core
O antigen (immunogenic)
O antigen (immunogenic)
Lipid A
Lipid A
(the toxicity of LPS depends on the
(the toxicity of LPS depends on the
structure of lipid A)
structure of lipid A)
Laboratory
Laboratory
identification of
identification of
Enterobacteriaceae
Enterobacteriaceae
species
species
Culture and isolation
Culture and isolation
Biochemical properties [
Biochemical properties [
biotyping
biotyping
]
]
(identification to genera and species)
(identification to genera and species)
Antigenic properties [
Antigenic properties [
serotyping
serotyping
]
]
based on somatic-O, capsular-K and on
based on somatic-O, capsular-K and on
flagella - H antigenes (identification to
flagella - H antigenes (identification to
species and different subgroups of this
species and different subgroups of this
species)
species)
Media for
Media for
Enterobacteriaceae
Enterobacteriaceae
Transporting media
Transporting media
Poorly selecting differential media
Poorly selecting differential media
(Levin’s medium/EMB agar, MacConkey’s
(Levin’s medium/EMB agar, MacConkey’s
medium)
medium)
Moderately selecting differential media
Moderately selecting differential media
(SS agar, Wilson-Blair’s medium)
(SS agar, Wilson-Blair’s medium)
Differential enrichment media
Differential enrichment media
(selenite broth of Leifson = SF broth)
(selenite broth of Leifson = SF broth)
Blood agar
Blood agar
Biochemical
Biochemical
identification of
identification of
Enterobacteriaceae
Enterobacteriaceae
1.
1.
Test on Kligler’s iron agar (KIA)
Test on Kligler’s iron agar (KIA)
2.
2.
Urease activity test
Urease activity test
3.
3.
Test for
Test for
I
I
ndol
ndol
4.
4.
M
M
ethyl red test
ethyl red test
5.
5.
V
V
oges-Proscauer’s test
oges-Proscauer’s test
6.
6.
C
C
itrinating test
itrinating test
7.
7.
IMVC
IMVC
test (3+4+5+6) (for
test (3+4+5+6) (for
E. coli,
E. coli,
Enterobacter
Enterobacter
spp
spp
.
.
)
)
8.
8.
API 20 Enterobacteriaceae (API 20 E)
API 20 Enterobacteriaceae (API 20 E)
Family:
Family:
Enterobacteriaceae
Enterobacteriaceae
(27 generas are included)
(27 generas are included)
Escherichia
Escherichia
spp.
spp.
Klebsiella
Klebsiella
spp.
spp.
Enterobacter
Enterobacter
spp.
spp.
Salmonella
Salmonella
spp.
spp.
Shigella
Shigella
spp.
spp.
Yersinia
Yersinia
spp.
spp.
Proteus
Proteus
spp.
spp.
Citrobacter
Citrobacter
spp.
spp.
Serratia
Serratia
spp.
spp.
Providencia
Providencia
spp.
spp.
Morganella
Morganella
spp.
spp.
Escherichia
Escherichia
coli
coli
General
General
properties
properties
Ferments lactose
Ferments lactose
on
on
MacConkey medium
MacConkey medium
Produses gas when
Produses gas when
fermenting glucose
fermenting glucose
Produces indole when
Produces indole when
breaking down
breaking down
tryptophane
tryptophane
Often hemolytic
Often hemolytic
(particularly urine
(particularly urine
isolates)
isolates)
Fimbriae are present
Fimbriae are present
(motility)
(motility)
Important opport.
Important opport.
pathogen (symbiont)
pathogen (symbiont)
Determinants of
Determinants of
E. coli
E. coli
pathogenicity
pathogenicity
LPS (endotoxin): fever,
LPS (endotoxin): fever,
leucopenia,hypoglycemia, hypotension,
leucopenia,hypoglycemia, hypotension,
shock, perfusion disorder in main
shock, perfusion disorder in main
organs,activation of complement,
organs,activation of complement,
intravascular coagulation)
intravascular coagulation)
Adhesion factors :unique P fimbrial
Adhesion factors :unique P fimbrial
antigens, antigen O
antigens, antigen O
Enterotoxins:
Enterotoxins:
Hemolysins
Hemolysins
Antiphagocytic capsule
Antiphagocytic capsule
E. coli
E. coli
enterotoxins
enterotoxins
Produced by the enterotoxigenic
Produced by the enterotoxigenic
strains of
strains of
E. coli
E. coli
(ETEC) (genes in
(ETEC) (genes in
plasmids):
plasmids):
–
heat-labile toxins (LT-I and LT-II): stimulate
heat-labile toxins (LT-I and LT-II): stimulate
adenyl cyclase – excretion of water and
adenyl cyclase – excretion of water and
chlorides, inhibition of absorption of natrium
chlorides, inhibition of absorption of natrium
–
heat-stable toxin (ST): binds to intracellular
heat-stable toxin (ST): binds to intracellular
guanylyl cyclase causing incerase of intracellular
guanylyl cyclase causing incerase of intracellular
cGMP concentration - disorder in ion transport
cGMP concentration - disorder in ion transport
Produced by the enterohemorrhagic
Produced by the enterohemorrhagic
strains of
strains of
E. coli
E. coli
(EHEC/VTEC):
(EHEC/VTEC):
–
verotoxin (VT) = Shiga-like toxin: inhibiits protein
verotoxin (VT) = Shiga-like toxin: inhibiits protein
synthesis
synthesis
Pathogenicity of
Pathogenicity of
E. coli
E. coli
Gastrointestinal disease
Gastrointestinal disease
Urinary tract infections
Urinary tract infections
Neonatal meningitis (most frequent
Neonatal meningitis (most frequent
factor)
factor)
(esp. capsular strains named
(esp. capsular strains named
E. coli
E. coli
K1)
K1)
Sporadically: sepsis, secondary
Sporadically: sepsis, secondary
pneumonia, iatrogenic and nosocomial
pneumonia, iatrogenic and nosocomial
infections
infections
„
„
Virulence types” of
Virulence types” of
pathogenic
pathogenic
E. coli
E. coli
(gastrointestinal
(gastrointestinal
disease)
disease)
Enterotoxigenic
Enterotoxigenic
E. coli
E. coli
(ETEC)
(ETEC)
Enterohemorrhagic
Enterohemorrhagic
E. coli
E. coli
(EHEC/VTEC)
(EHEC/VTEC)
Enteropathogenic
Enteropathogenic
E. coli
E. coli
(EPEC)
(EPEC)
Enteroadherent
Enteroadherent
E. coli
E. coli
(EAEC)
(EAEC)
Enteroinvasive
Enteroinvasive
E. coli
E. coli
(EIEC/INVEC)
(EIEC/INVEC)
Transmission of
Transmission of
E. coli
E. coli
Fecal-oral route
Fecal-oral route
Food-borne transmission
Food-borne transmission
Endogenous source
Endogenous source
Laboratory diagnosis of
Laboratory diagnosis of
E. coli
E. coli
infection
infection
Culture and isolation of
Culture and isolation of
E. coli
E. coli
(materials:
(materials:
feces, infected tissue, blood, urine);
feces, infected tissue, blood, urine);
culturing on differential medium
culturing on differential medium
(MacConkey’s agar, EMB agar), blood agar
(MacConkey’s agar, EMB agar), blood agar
Biochemical analysis (e.g. glucose
Biochemical analysis (e.g. glucose
fermentation, production of indol and
fermentation, production of indol and
H
H
2
2
S);
S);
biotyping
biotyping
(the result of
(the result of
IMVC
IMVC
test
test
for
for
E. coli
E. coli
: ++--)
: ++--)
Serotyping
Serotyping
– the serotype of a strain is
– the serotype of a strain is
defined by its full antigenic formula, its O,
defined by its full antigenic formula, its O,
K, and H anigens, e. g.
K, and H anigens, e. g.
E. coli
E. coli
O55 K59 H6
O55 K59 H6
Treatment of
Treatment of
E. coli
E. coli
infection
infection
Rehydration with electrolyte-rich liquids
Rehydration with electrolyte-rich liquids
Antibiotic therapy (in children, in extra-
Antibiotic therapy (in children, in extra-
intestinal infections, in chronic infections):
intestinal infections, in chronic infections):
trimethoprim-sulfamethoxasole;
trimethoprim-sulfamethoxasole;
also :
also :
Ampicillin
Ampicillin
Aminoglycosides
Aminoglycosides
Cephalosporins
Cephalosporins
Resistance!
Check
susceptibility
Coli titre
Coli titre
E. coli,
E. coli,
like other
like other
Enterobacteriaceae,
Enterobacteriaceae,
is known as the
is known as the
coliform
coliform
, so if
, so if
present in drinking water – evidence
present in drinking water – evidence
of fecal contamination
of fecal contamination
Coli titre
Coli titre
– for sanitary examination
– for sanitary examination
of drinking water: the minimum part
of drinking water: the minimum part
of water in which we can still find
of water in which we can still find
E.
E.
coli
coli
or other coliforms
or other coliforms
Klebsiella
Klebsiella
spp.
spp.
K. pneumoniae
K. pneumoniae
K. ozaenae
K. ozaenae
(stinking
(stinking
rhinitis = ozena)
rhinitis = ozena)
K. rhinoscleromatis
K. rhinoscleromatis
(inflammation of
(inflammation of
throat, nose, and
throat, nose, and
sinuses mucous
sinuses mucous
membrane =
membrane =
scleroma)
scleroma)
K. oxytoca
K. oxytoca
General properties of
General properties of
Klebsiella
Klebsiella
spp.
spp.
Gram-negative
Gram-negative
NON-MOTILE
NON-MOTILE
Rods
Rods
Mucoid capsule (with
Mucoid capsule (with
antigen K - capsullar
antigen K - capsullar
swelling test)
swelling test)
O antigens
O antigens
On solid medium: mucous
On solid medium: mucous
colonies
colonies
Ferment lactose in
Ferment lactose in
MacConkey’s medium
MacConkey’s medium
Ammonia production
Ammonia production
(urease activity)
(urease activity)
Determinants of
Determinants of
Klebsiella
Klebsiella
spp.
spp.
pathogenicity
pathogenicity
Mucoid antiphagocytic capsule
Mucoid antiphagocytic capsule
LPS
LPS
Plasmid exchange with other
Plasmid exchange with other
Enterobacteriaceae
Enterobacteriaceae
(inconstant
(inconstant
characteristics of antibiotic
characteristics of antibiotic
resistance - ESBL !)
resistance - ESBL !)
Ability to produce toxins similar to
Ability to produce toxins similar to
E.
E.
coli
coli
toxins
toxins
K. pneumoniae
K. pneumoniae
– clinical
– clinical
disease
disease
Destructive pneumonia with abscesses of
Destructive pneumonia with abscesses of
lungs
lungs
Meningitis (in newborns)
Meningitis (in newborns)
Epidemic diarrhea/enteritis (in newborns)
Epidemic diarrhea/enteritis (in newborns)
Urinary tract infections (children and
Urinary tract infections (children and
adults)
adults)
Bacteremia, septicemia
Bacteremia, septicemia
Nosocomial infections
Nosocomial infections
Sensitivity testing necessary because of
Sensitivity testing necessary because of
multiresistance to antibiotics (empirically:
multiresistance to antibiotics (empirically:
aminoglycosides and cephalosporins)
aminoglycosides and cephalosporins)
Enterobacter
Enterobacter
spp.
spp.
E. g.
E. g.
E. aerogenes
E. aerogenes
,
,
E.
E.
cloacae
cloacae
,
,
E. sakazaki, E.
E. sakazaki, E.
agglomerans
agglomerans
Often found in the normal
Often found in the normal
intestinal flora
intestinal flora
Beta-lactamases
Beta-lactamases
production
production
The result of IMVC test:
The result of IMVC test:
--
--
++
++
Pathogenicity: infections
Pathogenicity: infections
of urinary tract (urease),
of urinary tract (urease),
meningitis, bacteremia,
meningitis, bacteremia,
septicemia
septicemia
(often involved in
(often involved in
nosocomial infections)
nosocomial infections)