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Updated: Sep 26, 2026
Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria
Published on: September 16, 2013
[Extraction and characterization of the lipopolysaccharide of Bartonella quintana]
G. Matera1, M.C. Liberto, A. Pollio
1Cattedre di Microbiologia, Chimica e Propedeutica Biochimica e Patologia Clinica, Universita "Magna Graecia", Catanzaro, Italy.
Abstract:
Bartonella quintana has been reported as the cause of trench fever, persistent endocarditis, bacteriaemia and has been isolated with an increasing incidence in clinical specimens from AIDS patients. One of the main pathogenic factors of gram-negative bacteria, including B. quintana, is the lipopolysaccharide (LPS). However, very little information is available on the features of Bartonella LPS. The aim of the present study was to extract, purify and characterise B. quintana LPS. The effect of the LPS under scrutiny was also evaluated on TNFa release by means of the "in vitro" human whole blood model of sepsis. The Oklahoma strain of B. quintana was grown on sheep blood agar, at 37 C, in a moist atmosphere containing 5% carbon dioxide. Cells were harvested and washed in sterile and apyrogenic saline solution and LPS extracted following the procedure of Westphal e Jann (1965), modified by Minnick (1994). The LPS of B. quintana showed the migration pattern of a deep rough chemotype, and the chromogenic limulus amoebocyte lysate test (LAL test) revealed strong reactivity at low concentrations (6.2 pg/ml). Samples of human whole blood stimulated by 1000 ng/ml of B. quintana LPS released 1707 378 pg/ml of TNFa.
Insights
Bartonella quintana lipopolysaccharide (LPS) was extracted and purified, revealing a deep rough chemotype. This potent LPS strongly activated tumor necrosis factor-alpha (TNFa) release in human whole blood, indicating its role in sepsis.
Area of Science:
- Microbiology
- Immunology
- Bacterial Pathogenesis
Background:
- Bartonella quintana causes trench fever, endocarditis, and bacteremia, particularly in AIDS patients.
- Lipopolysaccharide (LPS) is a key virulence factor in Gram-negative bacteria, but its characteristics in Bartonella are poorly understood.
Purpose of the Study:
- To extract, purify, and characterize Bartonella quintana LPS.
- To evaluate the effect of B. quintana LPS on tumor necrosis factor-alpha (TNFa) release in an in vitro human whole blood model.
Main Methods:
- Bartonella quintana (Oklahoma strain) was cultured, and LPS was extracted using a modified Westphal & Jann method.
- LPS chemotype was determined by migration pattern, and its endotoxic activity was assessed using the Limulus amoebocyte lysate (LAL) test.
- TNFa release was measured in human whole blood stimulated with B. quintana LPS.
Main Results:
- B. quintana LPS exhibited a deep rough chemotype.
- The chromogenic LAL test showed high reactivity at low concentrations (6.2 pg/ml).
- Stimulation with 1000 ng/ml of B. quintana LPS induced significant TNFa release (1707 ± 378 pg/ml) in human whole blood.
Conclusions:
- Bartonella quintana LPS is a potent endotoxin with a deep rough chemotype.
- The strong activation of TNFa release suggests a significant role for B. quintana LPS in the inflammatory responses during infection and sepsis.
