Proton pump inhibitor (PPI) use increases the risk of Clostridium difficile infection (CDI) despite C. difficile spores being acid resistant. Swallowed saliva contains nitrite which reacts with gastric acid, producing bactericidal nitrogen oxides. With 5mM nitrite at pH 2 (reflecting normal gastric conditions) all C. difficile spores were killed within 15 min. No reduction in count was seen with the same nitrite concentration at pH 5, representing gastric conditions in patients taking PPIs, even after 60 min. Reduced gastric acidification of salivary nitrite may explain the increased risk of CDI in patients taking PPIs.
Keywords: Acidified nitrite; Clostridium difficile infection; Proton pump inhibitor; Spore.
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