Protective effects of <i>Helicobacter pylori</i> membrane vesicles against stress and antimicrobial agents.
Murray. Benjamin Oliver BO; Dawson. Robin Andrew RA; Alsharaf. Lolwah Mohammad LM; Anne Winter. Jody J
Key Findings
- H. pylori outer‑membrane vesicles (OMVs) protect the bacteria from hydrogen peroxide‑induced killing in a dose‑dependent way
- OMVs partially shield H. pylori from the antibiotics clarithromycin and levofloxacin but not from amoxicillin or metronidazole
- OMVs allow H. pylori to continue growing in the presence of antimicrobial peptide LL‑37, suggesting they may bind LL‑37 and release growth‑supporting nutrients
Practical Outcomes
- For biohackers focusing on gut health, this means H. pylori can resist some antimicrobial strategies, especially those relying on LL‑37 or certain antibiotics. Targeting H. pylori may require using drugs it isn’t protected against (like amoxicillin or metronidazole) or approaches that disrupt its vesicle production.
Summary
The study shows that tiny bubbles released by Helicobacter pylori (called outer‑membrane vesicles) help the bacteria survive harsh conditions, including the body’s natural antimicrobial peptide LL‑37 and some antibiotics. These vesicles act like shields, letting the bugs keep growing even when you try to kill them with certain drugs or the immune system’s defenses.
Abstract
Outer-membrane vesicles (OMVs) produced by <i>Helicobacter pylori</i> deliver bacterial components to host cells, provide a mechanism for stabilization of secreted components and may allow the bacteria to exert 'long-range' effects in the gastric niche, promoting persistence. In addition to their well-characterized host cell interactions, membrane vesicles improve stress survival in other bacterial species, and are constitutively produced by both pathogenic and non-pathogenic bacteria. We aimed to determine whether OMVs could improve <i>H. pylori</i> survival of a range of stressors. The effects of purified OMVs on the resistance of <i>H. pylori</i> to a range of environmental and antimicrobial stresses were determined using growth curves and survival assays. Addition of purified OMVs to <i>H. pylori</i> cultures provided dose-dependent protection against hydrogen peroxide-mediated killing. Supplementation with OMVs also partially protected <i>H. pylori</i> against the bactericidal effects of the antibiotics clarithromycin and levofloxacin, but not against amoxicillin nor metronidazole. Addition of purified OMVs allowed <i>H. pylori</i> to grow in the presence of inhibitory concentrations of the antimicrobial peptide LL-37. In the presence of 50 µg OMVs ml<sup>-1</sup>, significantly enhanced <i>H. pylori</i> growth was observed at higher LL-37 concentrations compared with lower LL-37 concentrations, suggesting that OMV-LL-37 interactions might facilitate release of growth-promoting nutrients. Taken together, these data indicate that production of membrane vesicles could help <i>H. pylori</i> to survive exposure to antibiotics and host antimicrobial defences during infection.
Study Information
pubmed
2020
2020-05-28T00:00:00.000Z
10.1099/mic.0.000934
30
35