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Updated: Sep 25, 2026
Detection of Helicobacter pylori Infection and Antibiotic Resistance via Stool Quantitative Polymerase Chain Reaction Analysis
Published on: May 16, 2025
Detection of Chlamydiae pneumoniae but not Helicobacter pylori DNA in atherosclerosis plaques
Maria P Dore1, Antonia R Sepulveda, Piero P Bacciu
1Institute of Internal Medicine, University of Sassari, Italy.
Insights
Chronic Helicobacter pylori (H. pylori) infection is linked to cardiovascular disease, but direct bacterial presence in plaques is unlikely. Atherosclerotic plaque antigens may cross-react with H. pylori factors, potentially increasing plaque instability.
Area of Science:
- Microbiology
- Cardiovascular Pathology
- Immunology
Background:
- Chronic infections are increasingly associated with cardiovascular diseases.
- Helicobacter pylori (H. pylori) and Chlamydiae pneumoniae are implicated pathogens.
- The direct role of these pathogens in atherosclerosis remains unclear.
Purpose of the Study:
- To investigate the presence and role of H. pylori and C. pneumoniae in atherosclerotic plaques.
- To determine if H. pylori antigens are directly present in atherosclerotic lesions.
- To explore potential cross-reactivity between microbial antigens and plaque components.
Main Methods:
- Analysis of atherosclerotic plaques from endarterectomy patients.
- Bacterial culture and PCR for H. pylori and C. pneumoniae detection.
- Immunohistochemical staining using anti-H. pylori vacA and cagA antibodies.
- Measurement of serum IgG antibodies against H. pylori and C. pneumoniae.
Main Results:
- High prevalence of serum IgG antibodies for both H. pylori (72%) and C. pneumoniae (81%).
- H. pylori DNA and culture were negative in all vessel wall and plaque samples.
- Immunohistochemical staining showed reactivity with H. pylori virulence factors in plaques, suggesting cross-reactivity.
- Chlamydiae pneumoniae DNA was detected in three atherosclerotic lesions.
Conclusions:
- The association between H. pylori infection and atherosclerosis is unlikely due to direct bacterial presence in vessel walls.
- Cross-reactivity between atherosclerotic plaque antigens and H. pylori virulence factors may contribute to plaque instability.
- Further research is needed to elucidate the role of C. pneumoniae in atherosclerosis.
Abstract:
Chronic infections have been associated with cardiovascular disease. We used bacterial culture, polymerase chain reaction (PCR), and immunohistochemical staining with anti-vacA and anticagA antibodies to search for Helicobacter pylori and Chlamydiae pneumoniae in atherosclerotic plaques obtained at endarterectomy. Serum IgG antibodies to H. pylori and C. pneumoniae were also determined. Thirty-two patients were enrolled. Anti-H. pylori and anti-C. pneumoniae IgG were present in 72% and 81%, respectively. Culture and PCR for H. pylori of vessel walls and plaques were negative. Atherosclerotic plaque and normal vessel sections from H. pylori-negative and- positive patients showed reactivity with anti-vacA and anti-cagA antibodies. C. pneumoniae DNA was amplified in three atherosclerotic lesions. These findings suggest that the association between H. pylori infection and atherosclerosis does not result from continuing direct effects of H. pylori antigens in the vessel walls. Antigens within vessel atherosclerotic plaques cross-react with H. pylori virulence factors and could act as cofactors in determining instability for the atherosclerotic plaques.
