A Novel Surface-Exposed Polypeptide Is Successfully Employed as a Target for Developing a Prototype One-Step Immunochromatographic Strip for Specific and Sensitive Direct Detection of Staphylococcus aureus Causing Neonatal Sepsis

Abstract

Neonatal sepsis is a life-threatening condition and Staphylococcus aureus is one of its major causes. However, to date, no rapid and sensitive diagnostic tool has been developed for its direct detection. Bioinformatics analyses identified a surface-exposed 112-amino acid polypeptide of the cell wall protein NWMN_1649, a surface protein involved in cell aggregation and biofilm formation, as being a species-specific and highly conserved moiety. The polypeptide was cloned, purified, and used to immunize mice to raise specific immunoglobulins. The purified antibodies were conjugated to gold nano-particles and used to assemble an immunochromatographic strip (ICS). The developed prototype ICS detected as low as 5 µg purified polypeptide and 102 CFU/mL S. aureus within 15 min. The strip showed superior ability to directly detect S. aureus in neonatal sepsis blood specimens without prior sample processing. Moreover, it showed no cross-reaction in specimens infected with two other major causes of neonatal sepsis; coagulase-negative staphylococci and Klebsiella pneumoniae. The selected NWMN_1649-derived polypeptide demonstrates success as a promising biomolecule upon which a prototype ICS has been developed. This ICS provides a rapid, direct, sensitive, and specific option for the detection of S. aureus causing neonatal sepsis. Such a tool is urgently needed especially in resources-limited countries.

Development of an Immunochromatographic Strip Using Conjugated Gold Nanoparticles for the Rapid Detection of Klebsiella pneumoniae Causing Neonatal Sepsis

“…ICS have also been developed for the detection of some bacterial pathogens, in particular foodborne pathogens and their toxins [ 46 ]. Development of ICS for the detection of human pathogens such as Mycobacterium tuberculosis [ 47 ], S. aureus [ 26 , 48 ], Helicobacter pylori [ 49 ], H. influenzae [ 50 ], and Neisseria gonorrhoeae [ 51 ] has been attempted, yet not as extensively as the previous applications.…”

“…Immunochromatographic strips (ICS) as diagnostic tests are easy to use and produce, rapid, cost-effective, and could be used as point-of-care tests by healthcare personnel [ 24 ]. Recently they have been increasingly attractive as diagnostic tools for microbial infections, especially when rapid diagnosis could be life-saving, such as with neonatal sepsis, and SARS-CoV-2 infections [ 25 , 26 ]. In this study, we design and evaluate a prototype immunochromatographic strip for the diagnosis of neonatal sepsis, employing K. pneumoniae -specific surface-exposed peptide as a target for nanogold-conjugated antibodies.…”

Advances in the Application of Nanomaterials as Treatments for Bacterial Infectious Diseases

“…Biofilm formation is critical in antimicrobial agent-resistance and treatment failure; however, so far there is no detection method to monitor the formation of biofilms. Anti-S. aureus antibodies were coupled with Au NPs to develop an immunochromatographic strip (ICS) [97]. The invented ICS could detect 10 2 CFU/mL S. aureus in 15 min among patients with neonatal sepsis [97].…”

“…Anti-S. aureus antibodies were coupled with Au NPs to develop an immunochromatographic strip (ICS) [97]. The invented ICS could detect 10 2 CFU/mL S. aureus in 15 min among patients with neonatal sepsis [97]. NP-based biosensors have been used to detect and prevent the formation of biofilms by disturbing the adhesion of bacteria to the surface of food [98].…”

Spontaneous pneumothorax associated with Staphylococcus aureus

“…Data on the microbial etiology of neonatal sepsis and the antimicrobial resistance profiles of its causative agents are needed to inform targeted and effective treatment and prevention strategies. [7][8][9][10][11][12][13][14][15][16][17][18][19][20] . We presented the case of a neonate neonatal S. aureus sepsis who developed a spontaneous pneumothorax.…”