… a bug that is the focus of a well-written review e-published recently in the Nature Group journal Cellular and Molecular Immunology: Interplay between Helicobacter pylori and immune cells in immune pathogenesis of gastric inflammation and mucosal pathology (PMID: 20190789) by two investigators from the Taipei Medical University, HF Tsai and PN Hsu.
The bug, H. pylori, is a Gram-negative (which means it is not stained purple by the Gram’s stain, and therefore, looks reddish pink due to the eosin counterstain under the microscope), micro-aerophilic (which means it can survive in conditions of minimal oxygen), curved-rod/helix shaped, flagellate (which means, it has a tail-like organelle that helps it to swim through fluid spaces) bacterium – a human pathogen that infects more than half the population of the world. Upon entering the stomach, H. pylori colonizes by attaching to the gastric epithelium (inner lining of the stomach wall), evades mucosal immunity by parking itself beneath the mucus in spots adjacent to the epithelium (which have a more neutral pH), and invades the gastric mucosa. Infection with H. pylori is associated with a chronic inflammatory response in the gastric mucosa, as well as enhanced apoptosis (‘programmed cell death’) of the gastric epithelial cells — which leads to chronic gastritis, peptic and duodenal ulcers, gastric carcinoma and gastric mucosa-associated (now known as ‘Marginal Zone’) lymphoid tissue (MALT) lymphomas. In more science-speak, interaction between the CCL20 (of the C-C chemokine family) and the chemokine receptor CCR6 recruits CD3+ T-cells to the sites of inflammation in the gastric mucosal epithelium inducing mucosal injury.
What’s my beef with the damned bug, you ask? I recently found out I have been unwittingly harboring it, its grandmother and cousins et al. Can you imagine the sneakiness, the audacity, the under-bleeping-handedness of this bug? And now I must endure at least a fortnights’ assault on my system by a combination of two antibiotics (amoxicillin and clarithromycin, which will hopefully kill the bug) and a proton-pump inhibitor (lansoprazole, which will take care of the excess acid secretion in the stomach, reducing the damage therefrom).
Oh, the horrors! Feel my wrath, O wretched bug – I curse thee to eternal damnation (not to mention, antibiotic-induced death)!
PS. For a general understanding, the Wikipedia article on H. pylori is quite informative.