Use of transformation to construct Neisseria gonorrhoeae strains with altered lipooligosaccharides.

DNA isolated from a nalidixic acid- and rifampin-resistant derivative of Neisseria gonorrhoeae serum-resistant strain 302 (MUG116), a strain that reacts with monoclonal antibody (MAb) 2-1-L8, was used to transform N. gonorrhoeae DOV, a serum-sensitive strain, to antibiotic resistance and/or reactivity with the MAb. MAb 2-1-L8 binds to a 3.6-kilodalton lipooligosaccharide (LOS). Reactivity with MAb 2-1-L8 transformed as a single marker and was unlinked to either of the antibiotic resistance markers. Immunoblot analysis of LOSs separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that new LOSs were synthesized in the transformed cells and that these LOSs corresponded to those of the DNA donor. Although multiple LOS components were made by the transformants, the MAb recognized only one. All transformants that were selected for on the basis of strong reactivity with MAb 2-1-L8 were serum resistant; however, the level of resistance correlated with the apparent loss of recipient LOS components. MAb 2-1-L8-reactive transformants that still produced DOV LOS components remained serum sensitive.