H. pylori is a gram-negative bacterium found in the human gastrointestinal tract that can cause chronic gastritis and peptic ulcers. It is transmitted through the fecal-oral route and its main virulence factors allow it to survive the acidic environment of the stomach. Diagnosis involves non-invasive tests like a blood antibody test or urea breath test, or invasive tests during endoscopy like a biopsy with rapid urease test. Left untreated, H. pylori infection can lead to complications like bleeding or perforation of peptic ulcers. Treatment involves combinations of antibiotics like amoxicillin, clarithromycin, and metronidazole alongside proton pump inhibitors.

1. Helicobacter pylori
Dr.ruaa Elias
College of Medicine
Department: Microbiology
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2. List of Contents:
 Objectives
 Introduction
 Important properties
 Source and Transmission
 Diagnosis
 Diseases
 Treatment
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3. Objectives:
-H. pylori has a great ability to resist destruction by
stomach acid.
-Human GI tract is the only reservoir for H. pylori
-H. pylori causing Chronic Gastritis and Duodenal
Peptic Ulcer .This ulceration is most often chronic and
recurrent and may lead to complication such as
bleeding, anemia, and perforation
-The students must learn all detail about the virulence
factors,pathogenicity and diagnosis, treatment of these
very important bacteria
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4. Introduction
-H. pylori is a genus of Gram-negative bacilli , bacteria in
the Enterobacteriaceae family.
-Transmission occurs via the fecal oral route.
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5. Important properties:
- Gram negative S-shape or comma shape rods
- Microaerophilic, fastidious, non-spore forming, non-
capsulated, motile bacteria.
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6. Source and Transmission
-Human GI tract is the only reservoir for H. pylori.
-Transmission occurs via the fecal oral route.
-There is a direct relationship between increased age
and increased likelihood of H. pylori infection
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7. Virulence factors
1- Endotoxin (lipopolysaccharide)
2- H. pylori has a great ability to resist
destruction by stomach acid.
3- Flagella enables movement into and within the
protective mucus layer of the stomach.
4- Urease enzyme generates ammonium ions to buffer
gastric acid; this enables survival within the hostile
acidic environment.
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8. Diagnosis
- Diagnosis of infection is usually made by checking for
dyspeptic symptoms and by tests which can indicate H.
pylori infection.
-One can test non invasively for H. plori infection with
a blood antibody test, stool antigen test
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9. -or with the carbon urea breath test (in which the patient
drinks 14C- or 13C-labelledurea, which the bacterium
metabolizes, producing labeled carbon dioxide that can be
detected in the breath).
Diagnosis
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10. Diagnosis
-However, the most reliable method for detecting H.
pylori infection is a biopsy check during endoscopy with
a rapid urease test, histological examination, and microbial
culture.
-There is also a urine ELISA test with a 96% sensitivity and
79% specificity.
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11. Diagnosis
-None of the test methods is completely failsafe. Even
biopsy is dependent on the location of the biopsy. Blood
antibody tests, for example, range from 76% to
84% sensitivity.
-Some drugs can affect H. pylori urease activity and
give false negatives with the urea-based tests.
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12. Electron micrograph of Helicobacter pylori possessing
multiple flagella (negative staining). The spiral
morphology of Helicobacter pylori
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13. Chronic Gastritis-
Symptoms: causes some nausea or upper
abdominal discomfort, but in many cases the patient is
asymptomatic.
-Duodenal Peptic Ulcer: (H. pylori is No. 1 causative
agent).
Symptoms: burning upper abdominal pain; occurs 1-3
hours after meals; pain is worse at night but relieved by
eating or use of anti-acids.
Diseases
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14. -This ulceration is most often chronic and recurrent and
may lead to complication such as bleeding, anemia,
and perforation.
-Gastric Peptic Ulcer: similar to duodenal ulcer Gastric
-Carcinoma: occurs in the setting of H. pylori
Diseases
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15. under the stomach mucus layer
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17. Treatment:
-Combination of the following :
-Ranitidine (H2 blocker) + Bismuth salts + Amoxycillin
+Metronidazole.
-Tetracycline can be substituted for
amoxycillin in penicillin allergy.
-Alternative combination: Clarithromycin +
metronidazole.
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18. Summary
H. pylori is a genus of Gram-negative bacilli , bacteria in the
Enterobacteriaceae family. Human GI tract is the only reservoir for H.
pylori. -Transmission occurs via the fecal oral route. Has Virulence
factors: Endotoxin (lipopolysaccharide), H. pylori has a great ability
to resist destruction by stomach acid, Flagella , Urease enzyme
generates ammonium ions to buffer gastric acid; this enables
survival within the hostile acidic environment. One can test non
invasively for H. plori infection with a blood antibody test, stool
antigen test the most reliable method for detecting H. pylori infection
is a biopsy check during endoscopy with a rapid urease test
, histological examination, and microbial culture. Chronic Gastritis
,Duodenal Peptic Ulcer, Gastric Peptic Ulcer: similar to duodenal
ulcer Gastric ,Carcinoma .treatment by Combination of the following
Ranitidine (H2 blocker) + Bismuth salts + Amoxycillin +Metronidazole
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19. References
 Medical Microbiology, edited by Jawetz,E.,
Brooks,G.F.; Carroll,K.C.;Butet,J.S.;
Mores,S.A.and Mietzner,T.A. 2010. 25 th ed.
 Medical Microbiology, edited by Jawetz,E.,
Brooks,G.F.; Butet,J.S and Mores,S.A. 2004. 23
th ed.
 Internet access
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20. Question?
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21. Thanks a lot
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