Culture-free diagnostics of Pseudomonas aeruginosa infection by silver nanorod array based SERS from clinical sputum samples

Abstract

Pseudomonas aeruginosa can cause major infection in immunocompromised patients, and successful antibiotic treatment of the infection relies on accurate and rapid identification of the infectious agents. Here, we reported a culture-free diagnostic method based on the surface-enhanced Raman spectroscopy (SERS) of pyocyanin (PCN), a major biomarker of P. aeruginosa. This platform can detect PCN as low as 5 ppb or 2.38 × 10−8 mol L−1 in both aqueous solutions and spiked clinical sputum samples. It has also been used to dynamically monitor the excretion of PCN by P. aeruginosa during its growth. The presence of PCN has been detected by SERS in 15 clinical sputum samples, which indicates P. aeruginosa infection, with 95.6% sensitivity and 93.3% specificity. The system can advantageously process multiple specimens rapidly, overcomes the need for bacterial culture and diagnostic microbiology assays, and have widespread implications in the early detection of P. aeruginosa infection.

Label-free molecular imaging of bacterial communities of the opportunistic pathogen Pseudomonas aeruginosa

“…PC1 loading plot (Figure 6A) generated from the analysis of the SERS image from a 2-day FRD1 pellicle biofilm (Figure 6B) reveals features at ~1352, 1511, 1572 and 1600 cm −1 . 22 These high z-score features resemble SERS bands representing a combined C-C/C-N stretch and C-H bend at 1352 cm −1 , C-C stretch, CH 3 wag and C-H in-plane bend at 1511 cm −1 present in the SERS spectrum of pyocyanin standard 33 (Figure 6A inset).…”

Raman and Surface-Enhanced Raman Scattering for Biofilm Characterization

“…It is a member of the quorum sensing system of Pseudomonas aeruginosa and is used as a biomarker for this bacteria species. The first study about the detection of pyocyanin in biofluid samples with SERS was performed by Wu et al [64] in 2014. Pyocyanin was detected in clinical sputum samples with 95.6% sensitivity and 93.3% specificity using a silver nanorod array as the SERS substrate.…”

“…Algae biofilms contain a polysaccharide-rich matrix Bacteria biofilms contain a protein-rich matrix [60] Escherichia coli Staphylococcus aureus DNA/RNA components (678, 802, and 1570 cm −1 ) [22] Escherichia coli Distinctive spectral features for monitoring bacterial death (DNA/RNA components, 678 cm −1 ) [61] Pseudomonas aeruginosa Detection of pyocyanin (1088, 1125, 1352 and 1613 cm −1 ) [64] Pseudomonas aeruginosa Plasmonic substrates were fabricated and used in label-free detection of pyocyanin [65] Pseudomonas aeruginosa C-C stretch, C-N stretch, and C-H in-plane bend modes were assigned as a marker peak of pyocyanin [66] Brevundimonas diminuta Staphylococcus aureus …”

Toward plasmonic monitoring of surface effects on bacterial quorum-sensing

“…In one of the pioneering works in this area, Costas and coworkers used a film of gold nanoparticles bound to protein receptors to detect quorum sensing activity in situ [53]. Previously, the majority of SERS studies of quorum sensing have been restricted to the measurement of liquid samples, rather than observation of quorum-sensing processes in situ [52,53,56]. Recent work in the area of micro-and nanostructured plasmonically-active substrates has shown that measurement of quorum sensing signals can also be achieved on patterned surfaces [54].…”