[Use of cell-surface antigens of Bacteroides thetaiotaomicron in the passive hemagglutination test and in the inhibition of passive hemagglutination].
The antigens were prepared from three B. thetaiotaomicron strains of different origin (NCTC 10582--reference strain, 312/85--isolated from a pancreas fistula drain of a patient, and 9/18--derived from normal human intestinal microflora). Lipopolysaccharides were extracted by the hot phenol-water method and purified by nuclease tretment. Degradation of lipopolysaccharides was achieved by mild acid hydrolysis obtaining polysaccharide (PS) and lipid (LA) fractions. Capsular polysaccharide (CPS) was extracted from the clinical strain 312/85 producing thick capsules. Antibacterial sera were prepared by immunization of rabbits with formolized suspensions of investigated strains. HA and IHA were performed with all antigens and immune sera. Examined cell-surface antigens (LPSs and CPS) were capable of coating formolized sheep erythrocytes. The titres obtained in the passive hemagglutination test in homologous reactions were 160-320. Polysaccharide fractions (PS) prepared by means of mild acid hydrolysis of LPSs were unable to coat formolized sheep red blood cells. The activity of sensitization of sheep erythrocytes was revealed by lipid fractions of LPSs. All preparations were active as inhibitors in the inhibition of passive hemagglutination. The strongest inhibitors in homologous systems were polysaccharide fractions of LPSs and capsular polysaccharide (the concentration of inhuibitor 8-15 micrograms/ml). The results of performed serological tests indicated the antigenic similarity of standard B. thetaiotaomicron strain NCTC 10582 and clinical strain 312/85. The strain 9/18 from normal human intestinal microflora showed distinct antigenicity. High-molecular cell-surface B. thetaiotaomicron antigens containing carbohydrates (LPS and CPS) can be applied in the passive hemagglutination test and in the inhibition of passive hemagglutination.
Rokosz
A
A
Zakład Bakteriologii Klinicznej AM w Warszawie.
Meisel-Mikołajczyk
F
F
D000818:Animals; D000954:Antigens, Surface / Q000302:isolation & purification / Q000494:pharmacology*; D001439:Bacteroides / Q000145:classification / Q000276:immunology*; D006384:Hemagglutination / Q000187:drug effects*; D006386:Hemagglutination Tests; D006801:Humans; D066298:In Vitro Techniques; D007422:Intestines / Q000382:microbiology; D008070:Lipopolysaccharides / Q000302:isolation & purification / Q000494:pharmacology*; D010185:Pancreatic Fistula / Q000382:microbiology; D011817:Rabbits; D012756:Sheep; D013045:Species Specificity
D000954:Antigens, Surface; D008070:Lipopolysaccharides