HELICOBACTER PYLORI UPDATE Dr.T.V.Rao MD 1

HELICOBACTER PYLORI
UPDATE
Dr.T.V.Rao MD
DR.T.V.RAO MD
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HISTORY OF H. PYLORI
• 1890’s: Spirochetes in animal stomachs
• 1900’s: Spirochetes in human stomachs
• 1954: No bacteria in gastric biopsies of 1000 patients
• 1975: Gram negative bacteria in 80% of GU’s
(Pseudomonas)
• 1983: Warren and Marshall characterize H. pylori
• 2005 Nobel prize in 2005
HELICOBACTER PYLORI
Background
Human stomach long considered inhospitable for
bacteria
Spiral shaped organisms occasionally visualized in
gastric mucous layer, but no evidence of disease
association
Organism classified first as Campylobacter pylori
Now Helicobacter pylori
Other species of Helicobacter isolated from
stomach, intestine of other animals
Marshall and Warren culture organism from human
gastric mucosa and show association with gastric
inflammation
DR.T.V.RAO MD
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HELICOBACTER
( WARREN AND MARSHAL )
• Campylobacter like organisms
• Spiral shaped colonizes Gastric mucosa
• Etiological agent in Gastritis and peptic ulcer
• Most important bacteria.
Helicobacter pylori
Colonizes 50 % of the Individuals
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WARREN AND MARSHAL WINS
NOBEL PRIZE
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GENERAL CHARACTERISTICS OF
HELICOBACTER
• Helicobacter pylori is major human pathogen associated with
gastric antral epithelium in patients with active chronic gastritis
• Stomach of many animal species also colonized
• Urease (gastric strains only), mucinase, and catalase positive
highly motile microorganisms
• Other Helicobacters: H. cinnaedi and H. fenneliae
• Colonize human intestinal tract
• Isolated from homosexual men with proctitis, proctocolitis,
enteritis, and bacteremia and are often transmitted through
sexual practices
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A silver stain of H. pylori on gastric mucussecreting epithelial cells (x1000).
From Dr. Marshall's stomach biopsy taken 8 days
after he drank a culture of H. pylori (1985).
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HELICOBACTER PYLORI
• Gram –ve spiral
shaped , motile
with unipolar tuft
of lopotrichus
flagella
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H. PYLORI BACTERIA
• Gram negative
• Spiral rod
• Unipolar flagella
• Microaerophilic
• Urease positive*
*Most important
character
*Scanning microscopic view of H. pylori
MORPHOLOGY & PHYSIOLOGY OF
HELICOBACTER
• Gram-negative; Helical (spiral or curved) (0.5-1.0 um X
2.5-5.0 um); Blunted/rounded ends in gastric biopsy
specimens; Cells become rod-like and coccoid on
prolonged culture
• Produce urease, mucinase, and catalase
• H. pylori tuft (lophotrichous) of 4-6 sheathed flagella
(30um X 2.5nm) attached at one pole
• Single polar flagellum on H. fennellae & H. cinaedi
• Smooth cell wall with unusual fatty acids
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H. PYLORI INFECTION
TRANSMISSION
• Transmissible
• Oral-oral and oralfecal
• Infects the human
stomach
• Produces inflammatory
response
• This brings up the point
of the importance of
“hand washing”
DYNAMICS OF H.PYLORI INFECTION
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CULTURING AND BIOCHEMICAL
CHARACTERS
• Grows on chocolate agar, Campylobacter media
• Grows under Microaerophilic conditions
• With presence of 5 – 20% co2
• Oxidase +
• Catalase –
• Urease strongly +++
• H2S
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H. PYLORI PATHOGENESIS
BACTERIAL VIRULENCE FACTORS
(CAG- PAI)( 37000 B-P – 29 GENES)
• Type IV secretions apparatus (1) (translocate cag A)
• Possible insertion by needle like organelle coated with a sheath (Cag 7
protein) [Rohde et al]
• Phosphorylated + binds to SHP-2 tyrosine Phosphates
Cytokine Production
IL- 8+ chemokines
Growth Factor
Like cellular response
(1) Odenbreit S, et al. Science 2000;287:1497-1500
H. PYLORI PATHOGENESIS
BACTERIAL VIRULENCE FACTORS
Ingestion
Evasion + Entrance of Mucus
1
Layer (Motility + Urea I)
2
Binding
3
Insertion
4
Intra cellular pathway
HELICOBACTER PYLORI AND PEPTIC ULCER DISEASE
HISTOPATHOLOGY WITH SPECIAL STAINS .
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H. PYLORI PATHOGENESIS
THE ROLE OF CYTOKINES
I. Alter secretion of mucus
II. TNF–α IL–Iß, INF- 1Y
•
↑ Gastrin release
Stimulate parietal cells
↑ Acid secretion
I. TNF–α
↓ D cells number
↓ Somatostatin
↑ Acid secretion
PATHOLOGY AND PATHOGENESIS
•
•
•
•
•
•
•
•
•
H.pylori colonizes gastric mucosa
Spread by oral – oral contact
Feco oral spread prominent
Poverty and overcrowding predisposes
Poor Hygiene
Causes mild to acute gastritis
Gastric antrum - causes gastric metaplasia
Any part of the stomach can be involved
Colonizes overlying mucosa but donot invade mucosa
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MAJOR LOCATION OFH.PYLORI
INFECTIONS
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Pathogenesis of Helicobacter Infections
 Colonize mucosal lining of stomach & duodenum in
man & animals
• Adherent to gastric surface epithelium or pit epithelial
cells deep within the mucosal crypts adjacent to gastric
mucosal cells
• Mucosa protects the stomach wall from its own gastric
milleu of digestive enzymes and hydrochloric acid
• Mucosa also protects Helicobacter from immune
response
 Most gastric adenocarcinomas and lymphomas are
concurrent with or preceded by an infection with H.
pylori
H.PYLORI INFECTING MUCOSAL
LAYER
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PATHOGENESIS OF H.PYLORI.
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Virulence Factors of Helicobacter
 Multiple polar, sheathed flagella
• Corkscrew motility enables penetration into viscous
environment (mucus)
 Adhesins: Hemagglutinins; Sialic acid binding
adhesin; Lewis blood group adhesin
 Mucinase: Degrades gastric mucus; Localized
tissue damage
 Urease converts urea (abundant in saliva and
gastric juices) into bicarbonate (to CO2) and
ammonia
• Neutralize the local acid environment
• Localized tissue damage
 Acid-inhibitory protein
H. Pylori Specific T
Cell and B Cell Responses
MECHANISM OF H.PYLORI INFECTION
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Urea Hydrolysis
Urea
C=O(NH2)2 + H+
Urease
+ 2H2O  HCO3- + 2 (NH4+)
Bicarbonate
And then…
CO2 + OH-
Ammonium
ions
HCO3- 
Virulence Factors of Helicobacter )
Tissue damage:
 Vacuolating cytotoxin: Epithelial cell damage
 Invasin(s)(??): Poorly defined (e.g., hemolysins;
phospholipases; alcohol dehydrogenase)
Protection from phagocytosis & intracellular killing:
 Superoxide dismutase
 Catalase
H. Pylori Pathogenesis and Application of
Cutting Edge Technologies
Molecular
biology
Genetics
Imaging
Cell culture
models
INDICATIONS FOR NONINVASIVE
TESTING FOR H. PYLORI *
• Strongly Recommended
• Dyspepsia
• History of/active peptic ulcer disease
• Gastric MALT lymphoma
• Following gastric cancer resection
• Following peptic ulcer surgery
• First-degree relative with gastric cancer
• Long-term Non-steroidal anti-inflamatory drugs (NSAID)
therapy
* In the absence of alarm signs for gastric cancer or ulcer disease
1. Malfertheiner P, et al. Aliment Pharmacol Ther. 2002;16:167. 2. Talley NJ et al. Aliment Pharmacol Ther.
1999;12:1135.
TYPES OF H. PYLORI TESTS
• Endoscopy
• Rapid urease
tests
• Histology
• Culture
• Serologic (antibody)
• Stool antigen tests
13
• C Urea blood
test
• Urea breath tests
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• C-urea
13
• C-urea
Malfertheiner P, et al. Aliment Pharmacol Ther. 2002;16:167.
13C
UREA BREATH TEST
• Detects active infection
• Sensitive and specific
• Non-radioactive
• No special handling
requirements
• Easy to collect and handle
sample
• Not indicated in pediatric
population
1. Graham DY et al. Am J Gastroenterol. 2001;96:1741. 2. Leodolter A et al. Am J Gastroenterol. 1999;94:2100.
LABORATORY DIAGNOSIS
• Diagnosed by Invasive and Non Invasive tests
• Invasive, Endoscopic Biopsy of Gastric mucosa
• Microscopy – Biopsy
• Culture
• Staining by special stains
• Gram staining
• Culture more sensitive 3 – 7 days
• Biopsy testing for urease detection in urea medium
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Laboratory Identification
 Recovered from or detected in endoscopic antral
gastric biopsy material; Multiple biopsies are taken
 Many different transport media
 Culture media containing whole or lysed blood
 Microaerophilic
 Grow well at 37oC, but not at 25 nor 42oC
 Like Campylobacter, does not use carbohydrates,
neither fermentatively nor oxidatively
DIAGNOSIS BY NON INVASIVE
METHODS
• Serology ELISA
• Urea breath test patient
swallows urea solution
In this test patient drinks
urea solutions labeled with
an isotope carbon
If H.pylori is present in the
urea is converted to
ammonia and co2 in the
breath measured.
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SUGGESTED GUIDELINES FOR
TREATMENT OF PATIENTS WITH GI OR ULCER
DISEASE
History & Physical Exam
Peptic ulcer
disease
Undifferentiated
dyspepsia
Positive
Symptoms
of GERD
Test for H. pylori
Eradication
therapy
Confirmation of cure
Malfertheiner P, et al. Aliment Pharmacol Ther. 2002;16:167.
Use of NSAIDs
or aspirin
SUGGESTED GUIDELINES FOR
TREATMENT OF PATIENTS WITH GI OR ULCER
DISEASE
History & Physical Exam
Peptic ulcer
disease
Undifferentiated
dyspepsia
Positive
Symptoms
of GERD
Test for H. pylori
Eradication
therapy
Confirmation of cure
Malfertheiner P, et al. Aliment Pharmacol Ther. 2002;16:167.
Use of NSAIDs
or aspirin
Negative
Treat for PUD,
Initiate PPI therapy,
or discontinue NSAIDs
TREATMENT
• Use of antibiotics, bismuth salts
• Ingestion of Bismuth subsalicylate
• Antibiotics Tetracycline's and metronidazole for two
weeks
• Use of Omeprazole
• Clarithromycin
• Do not treat for Asymptomatic colonization
• Drug resistance is a growing problem
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EMERGING DRUG RESISTANCE IN H.PYLORI
•
Antibiotic treatment does not always
completely inhibit or kill H. pylori
with potential for antibiotic
resistance. Resistance to antibiotics
is the single most important factor
for declining H. pylori eradication
rates.
•
In Japan, resistance to antibiotic
drugs has increased 400% while in
Taiwan, it is 500%. This means that
those who are infected while in
these countries may find the
bacterium rather resistant to their
antibiotic treatments.
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EPIDEMIOLOGY OF HELICOBACTER INFECTIONS
• Developed Countries:
• United States: 30% of total population infected
• Of those, ~1% per year develop duodenal ulcer
• ~1/3 eventually have peptic ulcer disease(PUD)
• 70% gastric ulcer cases colonized with H. pylori
• Low socioeconomic status predicts H. pylori infection
• Developing Countries:
• Hyperendemic
• About 10% acquisition rate per year for children between 2 and 8 years
of age
• Most adults infected but no disease
• Protective immunity from multiple childhood infections
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H.PYLORI CONTINUES TO BE AN
IMPORTANT PATHOGEN
• H. pylori is a transmissible, infectious disease with
potentially serious outcomes
• H. pylori infection may be asymptomatic or cause
dyspepsia
• Eradication therapy can cure H. pylori infection and
prevent morbidity and downstream events such as PUD
and gastric cancer
• Patients with symptoms of upper-GI disease, and who
use aspirin or NSAIDs should be tested for H. pylori
infection
• Programme Created by Dr.T.V.Rao MD
for Medical and Health Care Workers in
the Developing World
•
Email
• [email protected]
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