An immunochemical strategy based on peptidoglycan synthetic peptide epitopes to diagnose Staphylococcus aureus infections.
The characteristic pentaglycyl cross-bridge of the Staphylococcus aureus peptidoglycan (PG) cell wall component is an attractive epitope to raise specific antibodies against this microorganism. Based on this approach, we report here for the first time a competitive ELISA able to detect S. aureus down to 10(4) CFU mL(-1), without pre-enrichment on cell culture. The antibodies were raised against peptide-protein bioconjugates prepared by covalently coupling peptide haptens (PSau6 and PSau8) designed and synthesized taking into consideration the complex tridimensional structure in the PG polymer. Deglycosylation of the PG under acidic conditions has found to increase assay detectability. Assay performance has been evaluated in clinical samples such as bronchoalveolar lavage (BAL) and bronchoalveolar endotracheal aspirates (BAS) showing promising results for further implementation of this immunoassay as a daily routine diagnostic tool. Cross-reactivity studies have demonstrated that the immunoassay is specific for S. aureus.
Nanobiotechnology for Diagnostics (Nb4D), IQAC-CSIC, Jordi Girona, 18-26, 08034 Barcelona, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
Carme
C
Pastells
Combinatorial Chemistry Unit, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
Gerardo
G
Acosta
Nanobiotechnology for Diagnostics (Nb4D), IQAC-CSIC, Jordi Girona, 18-26, 08034 Barcelona, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
Nuria
N
Pascual
Combinatorial Chemistry Unit, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain; Department of Organic Chemistry, University of Barcelona, 080028 Barcelona, Spain; School of Chemistry, University of Kwa-Zulu-Natal, 4001 Durban, South Africa.
Fernando
F
Albericio
Combinatorial Chemistry Unit, Barcelona Science Park, Baldiri Reixac 10, 08028 Barcelona, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
Miriam
M
Royo
Nanobiotechnology for Diagnostics (Nb4D), IQAC-CSIC, Jordi Girona, 18-26, 08034 Barcelona, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain. Electronic address: pilar.marco@cid.csic.es.
M-Pilar
MP
Marco
D000907:Antibodies, Bacterial / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D006241:Haptens / Q000737:chemistry; D006801:Humans; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology*; D010457:Peptidoglycan / Q000737:chemistry*; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism
D000907:Antibodies, Bacterial; D000939:Epitopes; D006241:Haptens; D010455:Peptides; D010457:Peptidoglycan
Antibodies; Diagnostic; Immunoassay; Peptidoglycan; Staphylococcus aureus; Trifluoromethanesulfonic acid