Helicobacter pylori is a gram-negative, spiral-shaped bacterium that infects the stomachs of approximately half of the world's population. It is the primary cause of peptic ulcers and is associated with chronic gastritis and gastric cancer. In Pakistan, a study found the prevalence of H. pylori infection to be 74.4%, with risk factors including presence of household animals and larger family size. H. pylori infection is usually treated with a combination of proton pump inhibitors, antibiotics, and bismuth to achieve eradication rates as high as 93%.

1. Medical
Microbiology
by: group 3

2. Question
 Please talk about the characteristics of
bacterium Helicobacter pylori and its
population in the world (especially in
your country).

3. History & Taxonomy of Helicobacter
 Family not yet named (17 species by rRNA sequencing)
 First observed in 1983 as Campylobacter-like
organisms (formerly Campylobacter pyloridis) in the
stomachs of patients with type B gastritis
 Nomenclature of Helicobacter was first established
in 1989, but only three species are currently
considered to be human pathogens
Important Human Pathogens:
 Helicobacter pylori (human; no animal reservoir)
 H. cinaedi (male homosexuals; rodents)
 H. fenneliae (male homosexuals; rodents)

4.  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
General Characteristics of Helicobacter

6.  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
Morphology & Physiology of
Helicobacter

7. Helicobacter on Paramagnetic Beads

8.  Family Clusters
 Orally transmitted person-to-person (?)
Worldwide:
 ~ 20% below the age of 40 years are infected
 50% above the age of 60 years are infected
 H. pylori is uncommon in young children
Epidemiology of Helicobacter Infections

9. 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:
 Hyper endemic
 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
Epidemiology of Helicobacter Infections (cont.)

10. Prevalence and risk factors of Helicobacter
pylori infection among Pakistani population
Objective: Prevalence of H. pylori infection is higher in
developing countries including Pakistan. The basic purpose of
this study was to investigate the prevalence of H. pylori
infection and determination of possible risk factors.
Methodology: A prospective epidemiologic survey of H. pylori
infection was accomplished in 2008 and 2009 involving 516
asymptomatic individuals of Barakaho, Islamabad, Pakistan.
Data were obtained by questionnaire and H. pylori positivity
was checked by 13C UBT.
.

11. Results: A total of 516 individuals participated in the study
of which 384 (74.4%) were positive for H. pylori infection.
The prevalence was 73.5% in males and 75.4% in females
(p = 0.622) and increased with increasing age (p < 0.001).
Presence of household animals (p = 0.004) and more
family members (p = 0.025) were significantly correlated
with H. pylori prevalence while no association was seen
with other risk factors such as education level, drinking
water source, number of rooms in house and monthly
family income.
Conclusions: High prevalence of H. pylori infection in
Pakistani population is comparable to the data of
developing countries. H. pylori infection was significantly
associated with presence of household animals and more
family members

13. Virulence factors

14. Immune and Inflammatory
Response to H. pylori
Inflammatory Response Immune Response
H. pylori
Mucosa
Tissue damage
Activated T cell
Adhesion of bacteria
Inflammatory
Mediators
Activation
Recruitment
Gastric ulcer

15. • Majority of infected patients
do not develop clinically
significant disease
• Significant manifestations
– peptic ulcer disease (PUD)
– gastric and duodenal ulcers
– chronic gastritis
– mucosa associated lymphoid
tissue (MALT)
– gastric adenocarcinoma
H. pylori pathologic associations

18. Diagnosis

19. Diagnostic Test Comparison
• Invasive / active tests
• Noninvasive / passive tests
• Determination of presence of H. pylori
– antibodies in blood, serum, or saliva
– antigen in stool
– functional tests of the bacterium's urease enzyme
with a carbon-labeled urea breath test (
C-UBT)

20. Treatment
““ The modern treatment of peptic ulcersThe modern treatment of peptic ulcers
places emphasis on diet and rest.places emphasis on diet and rest.
The patient is fed a bland diet, andThe patient is fed a bland diet, and
small meals are given at frequentsmall meals are given at frequent
intervals.intervals.
Milk, cream and protein hydrolysates areMilk, cream and protein hydrolysates are
often prescribed between meals.often prescribed between meals.
Rest is essential. Some gastroenterologistRest is essential. Some gastroenterologist
routinely recommend hospitalization forroutinely recommend hospitalization for
several weeks…..several weeks…..

21. Triple Chemotherapy (synergism):
Proton pump inhibitor (e.g., omeprazole =
Prilosec(R))
One or more antibiotics (e.g., clarithromycin;
amoxicillin; metronidazole)
Bismuth compound
Inadequate treatment results in recurrence of symptoms
Treatment, Prevention & Control

22. Commercial Available Products

23. ConclusionConclusion
 H. pyloriH. pylori is the major cause of DU and itis the major cause of DU and it
should be eradicated in all patients testingshould be eradicated in all patients testing
positivepositive
 H. pyloriH. pylori relationship with therelationship with the
development of MALT and gastric cancerdevelopment of MALT and gastric cancer
 As high as 93% (158/170) eradication rateAs high as 93% (158/170) eradication rate
ofof H. pyloriH. pylori when quadruple therapy iswhen quadruple therapy is
usedused..
 Eradication rates vary between triple andEradication rates vary between triple and
quadruple therapiesquadruple therapies

24. Thank you
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