Typhoid fever is an acute systemic illness caused by Salmonella enterica serovar Typhi.

 

Typhoid fever remains a public health concern, with an estimated 22 million cases and 200,000 related deaths occurring worldwide each year.

 

The S. Typhi HlyE protein belongs to a class of pore-forming toxins with hemolytic and cytotoxic activities that are absent in other Salmonella enterica serovars.

 

The HlyE protein is expressed as a monomer, but it has a tendency to form non-functional soluble multimers in aqueous solution.

 

Serological studies have shown that S. Typhi and S. Paratyphi A strains produce substantial amounts of HlyE during human infection.

 

S. Typhi HlyE has been found in the plasma of patients with S. Typhi bacteremia and recent studies have identified that HlyE is an antigen that is capable of discriminating between typhoid patients and control subjects.

 

The reactivity of different Ig isotypes (IgG, IgA and IgM) against rHlyE has also been demonstrated by ELISA. (Ong et al. Microbial Immunol 2015; 59:43-47, Chin et al DOI: 10.7860/JCDR/2016/17801.7909).