T. Dasgupta et al., CHARACTERIZATION OF LIPOPOLYSACCHARIDE-DEFICIENT MUTANTS OF PSEUDOMONAS-AERUGINOSA DERIVED FROM SEROTYPE-O3, SEROTYPE-O5, AND SEROTYPE-O6, Infection and immunity, 62(3), 1994, pp. 809-817
Well-characterized rough mutants are important for the understanding o
f structures, functions, and biosynthesis of lipopolysaccharide (LPS)
in gram-negative organisms. In this study, three series of Pseudomonas
aeruginosa LPS-deficient mutants, namely PAC strains derived from ser
otype O3, AK strains derived from strain PAO1 (serotype O5), and serot
ype O6-derived mutants were subjected to biochemical analysis by sodiu
m dodecyl sulfate-polyacrylamide gel electrophoresis and silver staini
ng as well as immunochemical characterization using LPS-specific monoc
lonal antibodies. The O-side-chain deficiency among the O6-derived mut
ants was also examined, and three mutants, A28, R5, and H4, were subse
quently chosen for the elucidation of component sugars of the core str
ucture of serotype O6 LPS. LPS of strain A28 has L-rhamnose and propor
tionally higher amounts of D-glucose, a feature shared by the O5-deriv
ed mutant, strain AK1401 (previously demonstrated as a mutant with a c
ore-plus-one 0 repeat). In contrast, strains R5 and H4 were shown to b
e devoid of L-rhamnose and have low and undetectable amounts of D-gluc
ose, respectively, which indicated their core deficiency. The LPS-defi
cient or -sufficient characteristics of the P. aepuginosa strains exam
ined correlated well with serum sensitivity data. This report represen
ts a comprehensive analysis of rough mutants derived from 03 and 05 st
rains that have been used by others in many studies and a first look a
t the core oligosaccharide region of serotype O6 LPS obtained with the
O6-derived mutants generated in this study.