Complete urinary tract infection (UTI) diagnosis and antibiogram using surface enhanced Raman spectroscopy (SERS)

Abstract

There are three stages to a complete UTI diagnosis: (1) identification of a urine sample as positive/negative for an infection, (2) identification of the responsible bacterium, (3) antibiogram to determine the antibiotic to which the bacteria are most sensitive to. Using conventional methods, all three stages require bacterial cultures in order to provide results. This long delay in diagnosis causes a rise in ineffective treatments, chronic infections, health care costs and antibiotic resistance. In this work, SERS is used to identify a sample as positive/negative for a UTI as well as to obtain an antibiogram against different antibiotics. SERS spectra of serial dilutions of E. coli bacteria mixed with silver nanoparticles, showed a linear correlation between spectral intensity and concentration. For antibiotic sensitivity testing, SERS spectra of three species of gram negative bacteria were collected four hours after exposure to the antibiotics ciprofloxacin and amoxicillin. Spectral analysis revealed clear separation between bacterial samples exposed to antibiotics to which they were sensitive and samples exposed to antibiotics to which they were resistant. With the enhancement provided by SERS, the technique can be applied directly to urine samples leading to the development of a new, rapid method for UTI diagnosis and antibiogram.

Discrimination of urinary tract infection pathogens by means of their growth profiles using surface enhanced Raman scattering

“…On the other hand, reports for SERS-based detection of UTI pathogens are very few. Up to now, Pitris group published a few proceedings and an article about discrimination of bacteria grown in broth for 15-18 h and their antibiotic sensitivities [26][27][28][29]. Jarvis et al studied differentiation of bacteria grown on agar for 16 h [30].…”

A portable system for identifying urinary tract infection in primary care using a PC-based chromatic technique

“…Regardless of other clinical and microbiological factors this quantification cut-off is indicative of a UTI. This cut-off has also been used by Hadjigeorgiou et al (2012) in conjunction with their Raman spectroscopy studies of UTI.…”