Proteus mirabilis 2573 (ATCC 49565) produces an acidic capsular polysa
ccharide which was shown from glycose analysis, carboxyl reduction, me
thylation, periodate oxidation, and the application of one dimensional
and two-dimensional high-resolution nuclear magnetic resonance techni
ques to be a high-molecular-weight polymer of branched trisaccharide u
nits composed of 2-acetamido-2-deoxy-D-glucose (N-acetyl-D-glucosamine
), 2-acetamido-2,6-dideoxy-L-galactose (N-acetyl-L-fucosamine), and D-
glucuronic acid, having the structure: [GRAPHICS] P. mirabilis 2573 al
so produces an O:6 serotype lipopolysaccharide in which the O-chain co
mponent has the same structure as the homologous capsular polysacchari
de. This is the first report of a defined capsular polysaccharide in t
his bacterial genus.