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Helicobacter

Helicobacter. http://www.cdc.gov/ulcer/psas.htm. First one discovered in 1983 by Drs. Barry Marshall and J. Robin Warren Originally classified as a Campylobacter 22 species have now been discovered

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Helicobacter

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  1. Helicobacter http://www.cdc.gov/ulcer/psas.htm

  2. First one discovered in 1983 by Drs. Barry Marshall and J. Robin Warren • Originally classified as a Campylobacter • 22 species have now been discovered • The six that are associated with human disease are : H. pylori, H. cinaedi, H. fennellia, H. canadensis, H. canis, and H. pullorum • Table 33-3

  3. Physiology and Structure • Gram(-) spiral • Characterized by the 16s rRNA genes, fatty acids, and polar flagella on each end • Have bacillary or spiral shape in young cultures but take on a coccoid shape in older cultures • Requires microaerophilic environment with enriched medium agar and temperature must be between 30-37°C

  4. Diseases • Helicobacters are divided into two groups • Table 33-3 • Gastric • H. Pylori • Enteric • Other five bacterium • All cause gastroenteritis • H. fennelliae and H. cinaedi have been isolated from homosexual men with proctitis, proctocolitis and enteritis • Most of these diseases are uncommon and rare

  5. H. Pylori • 50% of the world population is infected • 70-90% in developing countries, usually before 10 years • Infections are much lower in the U.S. • About 45% of older adults are infected • More common in older adults, African Americans, Hispanics, and people with lower socioeconomic status • Cause peptic ulcers, duodenal ulcers, acute and cronic gastritis • Associated with almost 100% of all gastritis infections • 90% of duodenal ulcers, 80% of gastric ulcers • Persons with infection have a six fold greater chance of developing gastric cancer and MALT lymphoma

  6. Transmission • The actual mode of transmission is not yet known • CDC believes that it is by fecal-oral, or oral-oral routes • There have been incidents of transmission from contaminated endoscopes • A possible reservoir for H. pylori is contaminated water

  7. Prevention and Control • Wash hands • Eat properly prepared food • Drink clean water • A vaccine is in development • Bacteria appears to help prevent gastroesophageal (acid) reflux disease adenocarcinomas of the lower esophagus, so there is a question of whether to treat people that are asymtommatic

  8. Diagnosis • Microscopy • Gold standard • Invasive test • Urease Test • Breath analysis • Antigen detection • Stool specimen • Culture • Invasive procedure • Experienced microbiologists are more successful at culturing bacteria • Serology • Dignostic test of choice

  9. Virulence factors • Urease • Heat shock protein • Acid-inhibitory protein • Flagella, • Adhesins, • Mucanase, • Phospholipases, • Superoxide dismutase, • Catalase, • Vacuolationg Cytotoxin. • Table 33-4

  10. Treatment • Combination of antibiotics, H2 pump inhibitor, and bismuth • Triple therapies work better than double and longer use of the therapy help with the eradication • FDA has eight different treatments • http://www.cdc.gov/ulcer/md.htm

  11. H.pylori images courtesy of www.hpylori.com.au • www.cdc.gov • Medical Microbiology, Patrick R. Murray, Elsevier Mosby, 2005, pg. 350-354

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