Urinary tract infections: a review of the current diagnostics landscape

Abstract

Urinary tract infections are the most common bacterial infections worldwide. Infections can range from mild, recurrent (rUTI) to complicated (cUTIs), and are predominantly caused by uropathogenic Escherichia coli (UPEC). Antibiotic therapy is important to tackle infection; however, with the continued emergence of antibiotic resistance there is an urgent need to monitor the use of effective antibiotics through better stewardship measures. Currently, clinical diagnosis of UTIs relies on empiric methods supported by laboratory testing including cellular analysis (of both human and bacterial cells), dipstick analysis and phenotypic culture. Therefore, development of novel, sensitive and specific diagnostics is an important means to rationalise antibiotic therapy in patients. This review discusses the current diagnostic landscape and highlights promising novel diagnostic technologies in development that could aid in treatment and management of antibiotic-resistant UTIs.

Improving the diagnosis of urinary tract infections by the use of enriched media and a 48-hour incubation period

“…Each clinical microbiology laboratory chooses to follow a UTI diagnostic procedure based on the needs and characteristics of the treated population, as reflected in various guidelines [1, 2, 4, 6]. As the published information about the use of these procedures is scarce and out of date, we decided to assess the utility of a 48-hour BA culture in a 7 % CO 2 -enriched atmosphere compared to a 24-hour CRA culture in an aerobic atmosphere to determine the best method for a hospital attending predominantly urological and nephrological patients.…”

“…These recommendations advise performing urine cultures on cysteine–lactose–electrolyte-deficient agar or chromogenic agar (CRA), as well as on blood agar (BA), both types of culture being incubated for 24 hours. Optionally, a prolonged 48-hour incubation period and/or the use of other media cultures are suggested [1–5].…”

“…One of the most used methods involves test strip analysis, and, if the results indicate urinary tract pathology (presence of leucocyturia, haematuria and/or nitrites), confirmation by urine culture is needed. It is also common to include the examination of urinary sediment (manual or automated) to determine the presence of bacteria, leucocyturia and haematuria [4, 6–10]. Although guidelines recommend a longer BA culture of 48 hours [3], many laboratories still use a period of 18–24 hours [11–14].…”

LC-SRM combined with machine learning enables fast identification and quantification of bacterial pathogens in urinary tract infections

“…Urinary tract infections (UTIs) are one of the most common bacterial infections. 400 million people in the world contracted a UTI in 2019 and more than 230,000 of them died from it (1). UTIs mainly affect women (50-60%) and it has been shown that half of them will have at least one in their life, reducing their quality of life (2).…”

“…To date, the gold standard for detection and identification of bacterial cells in urine consists in a microbiological culture, followed by bacterial species identification using MALDI-TOF (matrixassisted laser desorption ionization-time of flight) mass spectrometry analysis (4)(5)(6). Due to the length of this culture, results can only be obtained in 24 to 48h (1,7), delaying appropriate antimicrobial treatment. Moreover, during this time, broad-spectrum antibiotics are often administered to the patient empirically, although this practice has been shown to be responsible for the occurrence of antimicrobial-resistant pathogens in the population (8)(9)(10).…”