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

• Published in: Biomolecules (Basel, Switzerland) Vol. 10; no. 11; p. 1580
• Main Authors: Mohamed, Sally A, Samir, Tamer M, Helmy, Omneya M, Elhosseiny, Noha M, Ali, Aliaa A, El-Kholy, Amani A, Attia, Ahmed S
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 20.11.2020; MDPI
• Subjects: Amino acids; Antibodies; Antigens; Biofilms; Bioinformatics; Cell aggregation; Cell surface; cell wall protein; Cell walls; Chromatography; Cloning; Coagulase; Cross-reaction; Deoxyribonucleic acid; direct detection; DNA; Genomes; Health aspects; immunochromatographic strip; Immunoglobulins; Methods; Nanoparticles; neonatal sepsis; Neonates; one–step; Pathogens; Physiological aspects; Polypeptides; Proteins; Sepsis; Staphylococcus aureus; Vectors (Biology); Germany; United Kingdom > UK; United States > US; one–step; direct detection; immunochromatographic strip; bioinformatics; rapid; neonatal sepsis; cell wall protein; Staphylococcus aureus
• ISSN: 2218-273X; 2218-273X
• DOI: 10.3390/biom10111580

Neonatal sepsis is a life-threatening condition and 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 10 CFU/mL within 15 min. The strip showed superior ability to directly detect 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 . 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 causing neonatal sepsis. Such a tool is urgently needed especially in resources-limited countries.