Elsevier

Talanta

Volume 234, 1 November 2021, 122644
Talanta

Selective point-of-care detection of pathogenic bacteria using sialic acid functionalized gold nanoparticles

https://doi.org/10.1016/j.talanta.2021.122644Get rights and content
Under a Creative Commons license
open access

Highlights

  • Sialic acid agglomerates gold nanoparticles only when Gram + bacteria are present.

  • The optical sensor developed revealed S. Aureus and MRSA presence by a simple colorimetric method.

  • The sensor was able to successfully discriminate wild type S. aureus and MRSA.

  • The sensor revealed staphylococcal presence in different complex media (TSB, serum).

  • This optical sensor was also able to discriminate between Gram+ and Gram-bacteria.

Abstract

In resource-limited settings, fast and simple point-of-need tests should facilitate healthcare providers the identification of pathogens avoiding empirical suboptimal treatments with broad-spectrum antibiotics. A rapid optical whole cell bacterial biosensor has been here developed using sialic acid functionalized gold nanoparticles allowing the selective screening of Gram-positive Staphylococcus aureus ATCC 25923 and Methicillin Resistant Staphylococcus aureus (MRSA) USA300 and Gram-negative bacteria (Pseudomonas aeruginosa ATCC 15442) by selecting the appropriate dispersing media. Those bacteria were selected due to their common presence in wound bed tissue of chronic infected topical wounds. The discrimination of bacterial pathogens has been attempted in different media including water, two independent buffers, bacterial broth, human serum and human urine. The identification of Gram + bacterial pathogens was also assessed under simultaneous co-culture of S. Aureus and Pseudomonas aeruginosa. High bacterial loads were required to provide with a statistically significant optical pathogen identification in human serum whereas it was not possible to detect the presence of bacteria at clinically relevant levels in urine.

Keywords

Antimicrobial discrimination tests
Bacteria
MRSA
Gold nanoparticles
Biosensor
Staphylococcus aureus

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