Fusion protein of Salmonella typhi flagellin as antigen for diagnosis of typhoid fever.

We previously established the specific 52 kDa antigen of Salmonella typhi, detected by our monoclonal antibodies, which was a flagellin protein. Comparison of the nucleotide sequences of phase-1 flagellin of Salmonella species available through GenBank database showed high homology at both ends of the genes with lower degree of homology in the middle portion which contained the antigenically variable regions. Thus, proteins from the central regions of flagellin genes should be species specific and could be used as specific antigens for the immunodiagnostic tests.

Molecular cloning and expression of Salmonella typhi flagellin: characterization of 52 kDa specific antigen of S. typhi.

We previously reported monoclonal antibodies (MAbs) specific to S. typhi 52 kDa antigen which do not cross react with related protein antigens from 11 bacteria causing enteric fever and enteric fever-like illness. Using the combination of these specific MAbs and recombinant DNA technology, expression plasmids containing the antigen gene producing substantial amount of the S.

Detection of Salmonella typhi protein antigen in serum and urine: a value for diagnosis of typhoid fever in an endemic area.

Using haemoculture as the gold standard, a double antibody sandwich ELISA for the detection of Salmonella typhi Barber protein antigen (BP) was compared with the Widal test. Specimens used were serum and urine obtained from normal healthy individuals and from patients with typhoid fever, paratyphoid fever, pyrexia caused by other bacteria and pyrexia with negative haemoculture. The ELISA for antigenuria gave a significantly higher sensitivity, specificity, accuracy and positive predictive value than the Widal test (p less than 0.

Systemic and intestinal immunities after different typhoid vaccinations.

The comparative studies of systemic and intestinal immunities to S. typhi were performed in 29 healthy volunteers during 2 years after receiving oral vaccination with attenuated S. typhi Ty21a in gelatin capsule, parenteral vaccination with acetone inactivated or heat inactivated-phenol preserved S.

Systemic and intestinal immunities after natural typhoid infection.

A 2-year study of systemic and intestinal immunity to Salmonella typhi was performed in 14 patients who were suffering from typhoid fever in an attempt to extrapolate the mechanism of immune responses in this disease. The methods employed were the leukocyte migration inhibition agarose test for the measurement of systemic cell-mediated immunity. The systemic immunoglobulin G (IgG) and IgM that were specific to S.