Biomarkers of urinary tract infections: state of the art, and promising applications for rapid strip-based chemical sensors

Abstract

Supplementary urinary tract infection biomarkers might help to improve the performance and reliability of urine test strips for high risk groups.

Metabolic Adaptations of Uropathogenic E. coli in the Urinary Tract

“…The metabolic profile of infected urine, as analyzed by metabolomics, may reveal promising biomarkers to be used for the diagnosis of UTIs. Several examples have already been identified, including trimethylamine and acetic acid, which have potential for incorporation on to a dip strip (Karlsen and Dong, 2015 ). Another example is creatinine, a breakdown product of creatine, defined as a biomarker for the diagnosis of nephropathy (Ariza-Heredia et al, 2014 ).…”

“…Similarly, metabolites related to purine and pyrimidine metabolism are upregulated in UPECs as compared to non-UPECs, for example guanine and hypoxanthine (Su et al, 2016a ). These two metabolites are known to be critical for the virulence of uropathogens (Vejborg et al, 2012 ; Karlsen and Dong, 2015 ), therefore hypoxanthine has the potential to be used as a biomarker for the diagnosis of UTIs. However, these potential markers for determining UTIs are from studies performed by culturing UPEC in urine obtained from healthy individuals under in vitro conditions (Karlsen and Dong, 2015 ), or by comparing the profile of metabolites produced by UPECs and non-UPECs under in vitro conditions (Su et al, 2016a ), which are settings that are in the absence of host immune and cellular responses.…”

“…These two metabolites are known to be critical for the virulence of uropathogens (Vejborg et al, 2012 ; Karlsen and Dong, 2015 ), therefore hypoxanthine has the potential to be used as a biomarker for the diagnosis of UTIs. However, these potential markers for determining UTIs are from studies performed by culturing UPEC in urine obtained from healthy individuals under in vitro conditions (Karlsen and Dong, 2015 ), or by comparing the profile of metabolites produced by UPECs and non-UPECs under in vitro conditions (Su et al, 2016a ), which are settings that are in the absence of host immune and cellular responses. The urinary composition of a healthy individual is highly likely to be very metabolically different from that of a UTI patient, partly due to the inflammatory response of the host.…”

Flow cytometric assessment of myeloperoxidase in bovine blood neutrophils and monocytes

“…The MPO enzyme transforms H 2 O 2 into hypochlorous acid, the latter being highly efficient in killing pathogenic invaders such as bacteria, but also potentially causing cytotoxic damage to the host tissue. In human medicine, MPO has evolved toward an important inflammation biomarker and is used as a diagnostic tool for acute bacterial infections (Kulander et al, 2001) and recently also in the diagnosis of wound (Blokhuis-Arkes et al, 2015) and urinary tract infections (Karlsen and Dong, 2015).…”

Sensitive and rapid lateral-flow assay for early detection of subclinical mammary infection in dairy cows

“…Moreover, it is essential for the transformation of hydrogen peroxide (H 2 O 2 ) into hypochlorous acid (HOCl) during the neutrophil's respiratory burst which is highly efficient in killing the invading microorganisms, and also causes huge cytotoxic damage to the host tissue 15,34 . The MPO www.nature.com/scientificreports/ enzyme is recognised as an inflammation biomarker in human medicine and is used as an important diagnostic tool for bacterial infections 35 , diagnosis of the wound 36 and the urinary tract infections 37 . Although MPO enzymes have been recognised as an important molecule that can be used efficiently to diagnose various bacterial infections in bovine, this is the first effort to develop LFA for the diagnosis of subclinical mastitis using this molecule.…”