The present study was undertaken to determine the possible
antigenic cross reactivity between four freshly isolated S.typhi strains
with (LPS antigen) with brucella and shigella antisera. These were done
by testing S.typhi positive LPS antigen against antisera of brucella
abort us, brucella meltinesis, shigella sonnei (phase 1 & 2), shigella
jlexeneri polyvalent (1-6, X &I9, shigella boydii polyvalent (I & 2 and
3) and shigella dysenteriae using immunoblotting and EL1SA methods.
The S.typhi strains were also tested for their ability to invade Henle 407
human intestinal cell lines and to test their cytotoxic effects on these cell
lines. The results obtained showed that there was no cross reactivity
between crude LPS antigen, of S.typhi and brucella abortus and
meltinesis, but cross reactivity was observed between these antigens and
shigella sonnei and flexeneri. Shigella dyesenteriae showed no cross
reactivity with LPS of S.typhi. The invasiveness of S.typhi to the Henle
407 human intestinal cell lines insure the major role of invasiveness of
S.typhi in the pathogenesis of S.typhic rather than the cytotoxic role in
this process. |