Outer membrane proteins analysis of Shigella sonnei and evaluation of their antigenicity in Shigella infected individuals

Abstract

Bacillary dysentery caused by infection with Shigella spp. remains as serious and common health problem throughout the world. It is a highly multi drug resistant organism and rarely identified from the patient at the early stage of infection. S. sonnei is the most frequently isolated species causing shigellosis in industrialized countries. The antigenicity of outer membrane protein of this pathogen expressed during human infection has not been identified to date. We have studied the antigenic outer membrane proteins expressed by S. sonnei, with the aim of identifying presence of specific IgA and IgG in human serum against the candidate protein biomarkers. Three antigenic OMPs sized 33.3, 43.8 and 100.3 kDa were uniquely recognized by IgA and IgG from patients with S. sonnei infection, and did not cross-react with sera from patients with other types of infection. The antigenic proteome data generated in this study are a first for OMPs of S. sonnei, and they provide important insights of human immune responses. Furthermore, numerous prime candidate proteins were identified which will aid the development of new diagnostic tools for the detection of S. sonnei.

Usefulness of the outer membrane proteins of Shigella sonnei in developing an antibody-based immunoassay for the diagnosis of shigellosis

“…Hence, significant efforts have been exerted in developing alternative methods in identification of Shigella. Detection of anti-S. sonnei antibodies in patients serum has been reported as a promising tool in screening/identification of Shigella sonnei by immunoassay techniques such as latex agglutination, immunodiffusion, radioimmunoassay, enzyme immunoassay, enzyme-linked immunosorbent assay (ELISA) and immunochromatography test (Harikrishnan et al, 2017;McPherson & Pincus, 2021). Development of such test would require the finding of specific antigenic proteins of Shigella to be used as biomarkers in the assay.…”

“…In addition, this assay is simple and easy to carry out, as well as can be used to investigate a large number of serum samples in a short period of time (Sudan & Shanker, 2013). Three potential proteins of outer membrane proteins (OMPs) of S. sonnei (33.3 kDa,43.8 kDa and 100.3 kDa), were reported as promising biomarker candidates to be used in the development of a rapid and reliable protein-based diagnostics for the identification of S. sonnei (Harikrishnan et al, 2014(Harikrishnan et al, , 2017. Thus, this study aims to further evaluate the potential of these protein candidates as diagnostic biomarkers in the development of an antibody-based immunoassay for the detection of S. sonnei in human.…”

Structural Insights into Substrate Binding and Antibiotic Inhibition of Enterobacterial Penicillin-Binding Protein 6

“…The 43.8-kDa protein from S. sonnei has been shown to uniquely cross react with human IgA and IgG [ 21 ]. However, the 3D structure of this protein is yet to be determined.…”

“…More importantly, a similar 43.8-kDa outer membrane-associated protein from S. sonnei has been shown to uniquely recognize immunoglobulin A (IgA) and IgG from patients previously infected by the bacterium, and interestingly, the protein did not cross-react with sera from patients that have been infected with other enteric infections [ 21 ]. Identification of such an antigenic protein that is specifically recognized by host antibodies would, therefore, guide us in the development of a new, fast and highly sensitive antigen-based test for specific detection of S. sonnei infections.…”

Reverse vaccinology approach for the identification and characterization of outer membrane proteins of Shigella flexneri as potential cellular- and antibody-dependent vaccine candidates

“…Further identification of immunogenic protective antigens is essentially required to develop effective subunit vaccines for shigellosis. Recent literatures reveal that the outer membrane proteins (OMPs) of Shigella are ideal targets for vaccine development [8]. It has been well established that the OMPs of Shigella are capable of induction of immunological response in animal models given these proteins play crucial role as dynamic interface during host-pathogen interaction [9].…”