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# Helicobacter pylori ## Bacteriological Characteristics * Gram-negative curved or spiral bacilli, mobile (polar flagella) * Absence of spores and capsule * Culture in microaerophile, 5 to 10% CO2 in 4 to 12 days * Virulence factors: * Cytotoxin-associated vacuoles → acid vacuoles in cells...

# Helicobacter pylori ## Bacteriological Characteristics * Gram-negative curved or spiral bacilli, mobile (polar flagella) * Absence of spores and capsule * Culture in microaerophile, 5 to 10% CO2 in 4 to 12 days * Virulence factors: * Cytotoxin-associated vacuoles → acid vacuoles in cells * Very active urease ++: release of ammonium ions that may neutralize gastric acidity around the bacteria. ## Clinical Aspects * HP infection frequently causes gastritis, often asymptomatic and persistent throughout life in the absence of eradication. * It may progress to more serious pathologies: * Gastric or duodenal ulcer (10% of cases) * Gastric cancer (1% of cases) * Maltoma lymphoma (rarely) ## Germ Resistance Treatment is currently recommended for: * Patients with proven ulcers * Patients with MALT lymphoma * In case of identified gastric atrophy, detected by simple detection of antigen in stool. ## Epidemiology * Humans are the primary reservoir of HP * HP is isolated in animals in contact with humans (pigs, sheep, captive monkeys, cockroaches) * Transmission is strictly human-to-human, primarily during early childhood and within families. * Three transmission routes are suspected: gastro-oral, oro-oral, and fecal-oral. * Prevalence increases progressively with age in industrialized countries. Infection rate is 5 to 10% in children and reaches 25 to 50% in adults.. ## Bacteriological Diagnosis ### Non-invasive Methods * **Serology:** useful for screening (ELISA, Western blot) * **Breath test** * **Stool antigen test:** important in cases where infection hasn't been confirmed by fibroscopy or biopsy. ### Invasive Methods * **Biopsy during upper endoscopy (3 biopsies):** to examine pathological specimens, for urease test and culture. * **Culture (obtained from the last biopsy):** * Highly demanding germ, requiring special media and microaerophilic atmosphere * Identification: urease +++ ## Treatment If diagnosis is confirmed by culture and antibiotic susceptibility test: * Treatment with proton pump inhibitors (anti-acids) and two antibiotics. * If not, * Quadruple bismuth therapy (PPI + bismuth citrate, metronidazole, tetracycline) * Concomitant treatment: amoxicillin, metronidazole, clarithromycin + PPI