Helicobacter
Campylobacter
vibro
Salmonella
shape
-ve curved bacilli
-ve curved bacilli (seagul)
-ve comma shaped bacilli
-ve rods
Motility
Motile by multipolar flagella
Motile by sigle polar
flagellum
Motile (darting motility)
Motile
Shigella
-ve rods
Brucella
-ve coccobacilli
Cl. Perfringens
Cl.botulinum
+ve rods
+ve rods
Motile
Non
Capsule
Non
Capsulated
Non
Spore
Non
Subterminal spore
Sporulated
worldwide &associated
with
MOI
® chronic superficial gastritis.
® gastric or duodenal ulcers
ingestion of contaminated
water, milk or
undercooked foods.
Commonest cause of
enterocolitis in children
Contaminated water or
food
Contaminated food
Contaminated food
Pathogenesis
® gastric carcinoma.
® Spiral shape For motility
® C. jejuni has LPS
within this mucous layer.
with endotoxin activity.
® Urease activity Which
® Cytopathic
generate ammonium lons
extracellular toxins
that buffer gastric acidity
® Enterotoxin.
® microaerobic :For survival
® small infecting dose Is
within the mucous gel
required to cause illness
® Attachment to epithelial cells By
as few as 800 bacteria
fimbria, adhesion
® illness gradually
occur after 2 – 4 days
® Penetrates the mucus
layer covering intestinal
mucosa by secretion of
neuraminidase and
proteases and adhere to the
mucosal cell by fimbriae
and outer proteins where
they subsequently produce
enterotoxin which causes
extensive diarhia →
dehydration, hypokalemia,
metabolic acidosis and
anuria
typhi and paratyphi
penetrate intestinal
epithelium → multiply in
mesenteric lymph nodes →
pass to blood stream →
septcemia (1st week) → shed
into gallbladder and goes to
lumen of intestine
s.typhimurium
s.enteritis: invade enteric
epithelium ( no systemic
infection) → cause diarrhea
and fever
Shigatoxin
exotoxin inhibit
protein synthesis and
has enterotoxic,
neurotoxic properties
multiply in large intestine
→ penetrate epith cell →
multiply intracellular →
tissue destruction →
dysentry (stool with blood &
mucous & pus) + ANVAC
D
® Handiling infected
animals
® contaminated milk
(Zoonosis)
® no human to human
infection
enter the gut →
reticuloendothelial system
→ multiply in
macrophage cells causing
granuloma → release
from granulomas cause
bacteraemia and fever
Reheated meat dishes
containing spores or
enterotoxin
Multiply producing
toxins:
® toxins form spores
make Ca influx
→ cause cell death
and intestinal damage
→ fluid & electrolite
loss
→ cause diarrhea and
abdominal colic
-Direct ingestion of toxins
-Wounds grow in necrotic
tissus
-In infant due to honey
contaminated with spore
® active cholinergic
nerves inhibitor
-preventing release of
acetylcholine cause
blurred vision and inability
to swallow and difficulty in
speaking and paralysis of
respiratory muscles and
death
incupation period cause
ANVAC D + fever.
® Large infectious dose
10*8 to 10*10
Culture
characters
Sample
Hoste defense
Gastric acidity & antitoxin
IGA
Gastric biopsy
Stool
Microaerobic
Microaerobc
Capnophilic 5-10%
Thermophilic 42
® Grow on nonselective
Media
media, as chocolate agar
® antibiotic containing selective
media:as Skirrow's medium and
incubate for 2- 5 days.
® Skirrow's medium:
containing vancomycin,
polymyxin and
trimethoprim is a
selective medium used
for their isolation from
stools.
Mucus flecks from
rice water stools.
Highly aerobic
Alkaline PH
® ordinary media TCBS
medium (thiosulphate
citrate bile sucrose),
® they give yellow colonies
as they ferment sucrose
® 1st week: Blood
® 2nd week: Stool,
serum
® 3rd week: Urine,
serum
stool which contains
mucus and blood.
O2 :facultative anaerobic
Co2 0,03%
temp: 37
ph 7.4
® ordinary media : grow
® enrichment : selenite ,Tetrathionate
® selective : SS (XLD)
® Indicator : macconkey → pale = non lactose fermenter
Blood, biopsy of
lymph node, spleen,
liver and bone
marrow.
Co2: 5 - 10%
tem :37
ph 7,4
O2 aerobic
® Need to be obtained
early in disease
® Blood agar and
trypticase soya agar
are media of choice
® no hemolysis on blood
agar
Identification
1 -film stain
® Campy blood agar: is
a selective medium
Colonies can be identified by
Gram & giemsa & acridine
orange & H&E stain.
® Examined by dark-field
or phase contrast
micrascopy for darting
motility.
® By Gram staining to
detect morphology
® Gram stain to show
morphology
® Dark field
microscope show
motility
Gram stain to show morphology
Gram staining is not
useful to show the
organisms in Clinical
specimens as they are
intracellular
Fecal samples are
the best specimens for
detecting toxin in food,
Food, feces, serum or
vomitus
Stool
O2 obligate anaerobe
CO2 0.03%
Temp. 37°C
PH 7.4
® egg yolk-glucose
agar or serum agar
® Ordinary media: grow
® Blood agar
® Robrtson cooked meat
medium
® Ordinary media: grow ®
Blood agar: haemolysis
® Robrtson cooked meat
medium
2 -BR
•
urease
•
•
oxidase
•
catalase positive
•
(3+ve).
•
Detection of H.pylori antigen in
the stool
ferments MGLS
with production
of acid only
positive cholera-red
reaction
oxidase +ve
Agglutination with V.
cholera O group 1
polyvalent antiserum
® Ferement : glucose,
mannite, maltose with
acid & gas production
Lactose is not
fermented
® H2S produced From
‘thiosulfate’
® O antibody appears
early and disappears
early
® H antibodies appears
late and disappears
late.
Serology
®So we can determine
the onset of infection by
interpreting the titre of
both O and H
antibodies
-If the O titre is higher
than the H titre this
means early infection
others
- If the H titre is higher
than the O titre this
means late infection
•
Rapid urase test
•
PCR
•
Rapid detection
•
Urea breth test
•
Culture confirmation
•
Typing of C jejuni
PCR for
PCR → Detect cholera
toxin gene
strains
treatment
Triple chemotherapy
•
PPI
•
Antibiotics(clarithromycin &
•
® Replacement therapy
for fluid loss
amoxicillin & metronidazole
® No value for antibiotics
Bithmuth component
but broad spectrum one
may be used to reduce
output of viable
organisms
® ferments MGLS
produces gases & acid s
® S. dyenteriae → glucose
,indole
® S. flexneri →
glucose,mannite, indole
® S. boydi → glucose,
mannite ,indole
® S. sonnei →
glucose,mannite ,late
fermentation for lactose
-----------------
® stormy clot in litmus
milk
® brucella agglutination
test
- slide or tube
agglutination test
- detect serum antibodies
against brucella
(diagnostic Tire :160 or
rising)
® ELISA to differentiate
between specific IgM
and IgG