Diagnosis of Bacterial Pathogens in the Urine of Urinary-Tract-Infection Patients Using Surface-Enhanced Raman Spectroscopy

Abstract

(1) Background: surface-enhanced Raman spectroscopy (SERS) is a novel method for bacteria identification. However, reported applications of SERS in clinical diagnosis are limited. In this study, we used cylindrical SERS chips to detect urine pathogens in urinary tract infection (UTI) patients. (2) Methods: Urine samples were retrieved from 108 UTI patients. A 10 mL urine sample was sent to conventional bacterial culture as a reference. Another 10 mL urine sample was loaded on a SERS chip for bacteria identification and antibiotic susceptibility. We concentrated the urine specimen if the intensity of the Raman spectrum required enhancement. The resulting Raman spectrum was analyzed by a recognition software to compare with spectrum-form reference bacteria and was further confirmed by principal component analysis (PCA). (3) Results: There were 97 samples with single bacteria species identified by conventional urine culture and, among them, 93 can be successfully identified by using SERS without sample concentration. There were four samples that needed concentration for bacteria identification. Antibiotic susceptibility can also be found by SERS. There were seven mixed flora infections found by conventional culture, which can only be identified by the PCA method. (4) Conclusions: SERS can be used in the diagnosis of urinary tract infection with the aid of the recognition software and PCA.

Applications of Raman Spectroscopy in Bacterial Infections: Principles, Advantages, and Shortcomings

“…In specificity, SERS is an enhanced RS through sample molecules interacting with surface plasmons of nanoscale structured metal surfaces, which often uses spherical nanoparticles made of silver or gold with diameters ranging from 20 to 100 nm ( Krafft and Popp, 2014 ). For example, Tien et al (2018) investigated bacterial pathogens in 108 urine samples sourced from of urinary tract infection patients; according to the study, 93 samples were detected with single bacterial species via SERS, while 97 samples were confirmed pathogen positive through medium culture, which makes the detection 95.87% accurate. Currently, although SERS is a highly promising analytical technique, it has not been used as a routine diagnostic method in the clinical laboratory yet, and there are many problems preventing its real-world application.…”

Enhancing Disease Diagnosis: Biomedical Applications of Surface-Enhanced Raman Scattering

“…In this study, 21 clinical isolates responsible for UTI, including Escherichia coli, Enterococcus spp., Klebsiella pneumoniae and Proteus mirabilis, were identified and classified accurately at species and strain level without recourse to DNA methods. To solve reproducibility problems linked to the simple mixing method applied by Jarvis and other authors [72,114,115], Shanmukh et al developed robust clinical grade fabricated solid Ag nanorods to classify molecular signatures of respiratory syncytial virus (RSV) associated with bronchiolitis [116], whilst Chen et al proposed aggregated Au/AgNP covered SiO 2 solid substrates to detect phenotypes of resistant etiological agents of sexually transmitted infections (STIs) in just 10 s [117]. In a further analysis, SERS was extended to diagnosis of aggressive fungal diseases, in order to discriminate among dermatophyte fungi strains responsible for mycotic infections using reproducible commercial Ag-coated NPs [118].…”

Rapid uropathogen identification using surface enhanced Raman spectroscopy active filters

“…SERS mediated uropathogen identification has been achieved with accuracies of up to 95.8% (e.g. 18 , 21 , 34 , 38 – 44 ). However, circumventing bacterial amplification has required complex processes such as immunocapture, dielectrophoresis and use of optical tweezers to capture or aggregate pathogens, which are technically challenging or require expensive equipment 39 , 45 .…”