[Use of reactions with Limulus amoebocyte lysate (LAL) to determine biological activity of lipopolysaccharides from reference and clinical strains of the Bacteroides fragilis group].
The aim of this study was to determine and compare a biological activity of lipopolysaccharides (LPS) from reference and clinical strains of strictly anaerobic bacteria belonging to the Bacteroides fragilis group (BFG) by means of quantitative, photometric BET (LAL) method with Limulus polyphemus amoebocyte lysate and chromogenic substrate S-2423. Lipopolysaccharides of five BFG species were extracted by Westphal and Jann method (1965) from eight reference and two clinical strains of B. fragilis group. Crude LPS preparations were purified according to the procedure described by Gmeiner (1975) with ultracentrifugation and nuclease treatment. Biological activities of bacterial endotoxins were determined by quantitative BET method with chromogenic substrate S-2423 (ENDOCHROME kit, Charles River Endosafe Ltd., USA). Tests were performed according to the producer's recommendations. E. coli O55:B5 LPS was applied to compare its activity in reaction with LAL reagent with activities of LPS preparations from rods of the Bacteroides genus. Among examined bacterial compounds the most active in BET method was E. coli O55:B5 LPS. Activities of lipopolysaccharides from five species of BFG rods in reaction with Limulus amoebocyte lysate were differentiated. Greater ability to activate LAL proenzyme revealed lipopolysaccharides of these species of the Bacteroides genus, which are important from the clinical point of view--B. fragilis and B. thetaiotaomicron.
Rokosz
Alicja
A
Katedra i Zakład Mikrobiologii Lekarskiej AM w Warszawie.
Fiejka
Maria
M
Górska
Paulina
P
Aleksandrowicz
Janina
J
Meisel-Mikołajczyk
Felicja
F
Łuczak
MirosŁaw
M
D001441:Bacteroides fragilis / Q000378:metabolism*; D004731:Endotoxins / Q000145:classification / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000378:metabolism*; D008565:Membrane Proteins / Q000145:classification / Q000378:metabolism*
D004731:Endotoxins; D008070:Lipopolysaccharides; D008565:Membrane Proteins; C025357:endotoxin binding proteins