Monoclonal antibodies to Bacteroides fragilis lipopolysaccharide

Abstract

Monoclonal antibodies (MoAbs) to the lipopolysaccharide (LPS) of Bacteroides fragilis were produced by immunizing mice before hybridization with bacterial outer membranes solubilized with Triton X-100. Nineteen stabile clones were established. They all produced antibodies that reacted more strongly with purified B. fragilis LPS than with crude sonicated antigen in an enzyme immunoassay. Four MoAbs were studied by immunoblotting and enzyme immunoassay inhibition. Immunoblotting confirmed that the target of the MoAbs was LPS. Marked and homogeneous staining occurred in the immunoblotting with both purified LPS and outer membranes in the molecular weight range of 8,000 to 27,000. In enzyme immunoassay inhibition, MoAbs reacted positively with 93 to 96% of B. fragilis strains, including prototype strains ATCC 23745 and NCTC 9343. Within the B. fragilis group, the MoAbs reacted positively with two of five B. ovatus strains and two to six of nine B. thetaiotaomicron strains. No marked cross-reactivity with other bacteria was observed. These results confirm earlier findings that the B. fragilis LPS contains an immunodominant antigenic determinant common to almost all B. fragilis isolates.

Bacteroides fragilis lipopolysaccharide and group B streptococcus serotype II glycocalyx have a common major antigenic determinant

“…The target determinant was found to be immunologically dominant among other LPS and outer membrane (OM) structures. The determinant could be shown in nearly all B. fragilis isolates studied (96%), which warrants the use of MAB in the diagnosis of B. fragilis infections (Linko-Kettunen et al 1984, Viljanen et al 1988).…”

“…The production of MAB has been described elsewhere (Linko-Kettunen et al 1984). Briefly: BALB/c mice were immunized with a B. fragilis outer membrane preparation.…”

“…Earlier we have described the production and characterization of a monoclonal antibody (MAB) that reacts with the p-1 -6-linked digalactose determinant in the outer core of B.fragilis lipopolysaccharide (LPS) , Linko-Kettunen et al 1984). The target determinant was found to be immunologically dominant among other LPS and outer membrane (OM) structures.…”

Comparison of polyclonal and monoclonal antibodies to Actinomyces and Arachnia species

“…Most of the strains used for specificity testing (Tables 2 and 3) were isolated from clinicai specimens at the National Public Health Institute, Helsinki, and the Department of Medical Microbiology, University of Turku, Finland, and identified as described earlier (6). In addition, the following reference strains wexe tised in specificity testing: Bacteroides fragilis (ATCC 23745), B. thetaiotaomicron (ATCC 29148), Clostridium difficile (ATCC 9689), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 27736), Pseudomonas aeruginosa (ATCC 9721), Legionella pneumophila (ATCC 33152), Staphylococcus aureus (ATCC 25923), and B. fragilis (NCTC 9343, National Collection of Type Cultures, Central Public Health Laboratory, London).…”

“…In addition, the following reference strains wexe tised in specificity testing: Bacteroides fragilis (ATCC 23745), B. thetaiotaomicron (ATCC 29148), Clostridium difficile (ATCC 9689), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 27736), Pseudomonas aeruginosa (ATCC 9721), Legionella pneumophila (ATCC 33152), Staphylococcus aureus (ATCC 25923), and B. fragilis (NCTC 9343, National Collection of Type Cultures, Central Public Health Laboratory, London). Maintaining of stock cultures of bacteria and purity controls were performed as described earlier (6).…”