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Skin own bacteria may aggravate inflammatory and occlusive changes in atherosclerotic arteries of lower limbs
P Andziak1, W L Olszewski, M Moscicka-Wesolowska
1Department of Surgical Research and Transplantology, Medical Research Center, Polish Academy of Sciences, Warsaw, Poland.
Aim:
Seroepidemiological studies have given rise to the hypothesis that microorganisms like Chlamydia pneumoniae (CP), Helicobacter pylori (HP), cytomegalovirus (CMV), HCV types 1 and 2, and bacteria involved in dental or other unspecified infection sites may initiate or maintain the atherosclerotic process in lower limb arteries. However, not much attention has been attached to the patient's own limb skin and deep tissues bacterial flora, activated in ischemic tissues. This flora may enhance the inflammatory and thrombotic process in the atherosclerotic arteries. Lower limb tissues are exposed to microorganisms from the environment (foot) and microbes on floating epidermal cells from the perineal and anal regions. The aim of this paper was to identify microbial cells and their DNA in perivascular tissues and arterial walls of lower limbs.
Methods:
Bacterial cultures and PCR method for detection of 16sRNA and immunohistopathological staining for identification of immune cells infiltrating vascular bundles.
Results:
1) specimens of atherosclerotic calf and femoral arteries contained bacterial isolates and/or their DNA, whereas, in control normal cadaveric organ donors' limb arteries or patients' carotid arteries and aorta bacteria they were detected only sporadically; 2) lower limb lymphatics contained bacterial cells in 76% of specimens, whereas controls only in 10%; 3) isolates from limb arteries and lymphatics belonged in majority to the coagulase-negative staphylococci and S.aureus, however, other highly pathogenic strains were also detected; 4) immunohistopathological evaluation arterial walls showed dense focal infiltrates of granulocytes and macrophages.
Conclusion:
Own bacterial isolates can be responsible for dense neutrophil and macrophage inflitrates of atherosclerotic walls and periarterial tissue in lower limbs and aggravate the ischemic changes.
Insights
The patient's own bacterial flora in lower limb tissues may contribute to atherosclerosis. This study identified bacterial DNA and cells in atherosclerotic arteries and lymphatics, suggesting a role in inflammation and ischemic changes.
Area of Science:
- Vascular Biology
- Microbiology
- Immunology
Background:
- Seroepidemiological studies suggest infections may initiate atherosclerosis.
- The role of indigenous bacterial flora in lower limb artery disease is understudied.
- Ischemic lower limb tissues may activate local microbial communities.
Purpose of the Study:
- To identify microbial cells and DNA in lower limb arterial walls and surrounding tissues.
- To investigate the association between local bacterial flora and atherosclerotic changes.
- To explore the potential contribution of indigenous microbes to lower limb ischemia.
Main Methods:
- Bacterial cultures were performed on arterial and lymphatic specimens.
- PCR detected bacterial 16sRNA in tissue samples.
- Immunohistopathology identified immune cells within vascular tissues.
Main Results:
- Bacteria and/or their DNA were found in atherosclerotic lower limb arteries, but rarely in controls.
- Bacterial cells were present in 76% of lower limb lymphatics versus 10% in controls.
- Isolates included staphylococci and other pathogenic bacteria; arterial walls showed neutrophil and macrophage infiltration.
Conclusions:
- Indigenous bacterial isolates may drive neutrophil and macrophage infiltration in atherosclerotic lower limb arteries.
- This inflammatory response could exacerbate ischemic changes in the lower limbs.
- The patient's own bacterial flora is a potential factor in lower limb atherosclerosis progression.
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