Multi-isotype antibody responses against the multimeric Salmonella Typhi recombinant hemolysin E antigen

Area of Science:

• Immunology
• Infectious Diseases
• Microbiology

Background:

• Antibody isotypes in serum are key indicators for diagnosing typhoid fever stages.
• Salmonella Typhi recombinant hemolysin E (HlyE) has potential for detecting immune responses.

Purpose of the Study:

• To investigate the efficacy of S. Typhi HlyE in detecting multi-isotype antibody responses in typhoid and paratyphoid A patients.
• To evaluate the diagnostic potential of an indirect antibody immunoassay utilizing HlyE.

Main Methods:

• An indirect antibody immunoassay was developed using S. Typhi recombinant hemolysin E (HlyE).
• The assay was tested on sera from 100 individuals, including patients with typhoid and paratyphoid A.
• Enzyme-Linked Immunosorbent Assay (ELISA) was used to measure IgG and IgA antibody isotypes.

Main Results:

• Nanogram quantities of HlyE were sufficient for detecting IgG and IgA isotypes.
• The immunoassay successfully distinguished between sera from typhoid and non-typhoid individuals.
• The ELISA demonstrated an overall sensitivity of 70%, specificity of 100%, and efficiency of 83%.

Conclusions:

• S. Typhi HlyE is a viable antigen for developing sensitive immunoassays for typhoid diagnosis.
• The HlyE-based immunoassay shows promise for differentiating typhoid infections from other conditions.