Recent advances in recurrent urinary tract infection from pathogenesis and biomarkers to prevention

Abstract

Recurrent urinary tract infection (UTI) might be one of the most common problems in urological clinics. Recent research has revealed novel evidence about recurrent UTI and it should be considered a different disease from the first infection. The pathogenesis of recurrent UTI might include two mechanisms, bacterial factors and deficiencies in host defense. Bacterial survival in the urinary bladder after antibiotic treatment and progression to form intracellular bacterial communities might be the most important bacterial factors. In host defense deficiency, a defect in pathogen recognition and urothelial barrier function impairment play the most important roles. Immunodeficiency and urogenital tract anatomical abnormalities have been considered the essential risk factors for recurrent UTI. In healthy women, voiding dysfunction and behavioral factors also increase the risk of recurrent UTI. Sexual intercourse and estrogen deficiency in postmenopausal women might have the strongest association with recurrent UTI. Traditional lifestyle factors such as fluid intake and diet are not considered independent risk factors now. Serum and urine biomarkers to predict recurrent UTI from the first infection have also attracted a wide attention recently. Current clinical evidence suggests that serum macrophage colony-stimulating factor and urinary nerve growth factor have potential predictive value for recurrent UTI. Clinical trials have proven the efficacy of the oral immunoactive agent OM-89 for the prevention of UTI. Vaccines for recurrent UTI are recommended by the latest guidelines and are available on the market.

Trend of Bacterial Uropathogens and Their Susceptibility Pattern: Study of Single Academic High-Volume Center in Italy (2015–2019)

“…Furthermore, these infections are associated with an important burden of morbidity and mortality and are second only to respiratory tract infections [ 2 ]. UTIs are estimated to affect approximately 150 million people each year in the world [ 3 ]. These infections cause more than 7 million medical visits and about 100,000 hospitalizations annually.…”

“…UTI prevalence varies with age, gender, time of catheterization, hospital admission, and extensive antibiotic therapy [ 9 ]. Bacteria represent the leading cause of UTIs [ 3 ]. Gram-negative bacteria lead the 90% of UTIs, while only 10% of these infections are caused by Gram-positive bacteria [ 10 , 11 ].…”

Identification of clinical and urine biomarkers for uncomplicated urinary tract infection using machine learning algorithms

“…The specificity of blood immune markers is limited by the possibility of cross-reactivity due to other infections or inflammatory responses. Urinary biomarkers that might reflect local immunological responses by the bladder epithelium include nerve growth factor (NGF), chemokines including IL-8/CXCL8 5,6 and antimicrobial peptides (AMPs), human α-defensin 5 (HD5) 7 and neutrophil gelatinase-associated lipocalin (NGAL) 8 . However, there is a lack of comprehensive biomarker screening studies for UTI.…”

Recurrent urinary tract infection in women and overactive bladder – Is there a relationship?

“…Treatment of recurrent UTI should follow the following sequence: (1) correct possible LUTD, large PVR, and high voiding pressure; (2) behavioral modifications and avoidance of risk factors; (3) nonantimicrobial measures; and (4) antimicrobial prophylaxis, which should be attempted also in this order[ 47 75 ]. Antimicrobial prophylaxis should be used after nonantimicrobial therapy failure[ 47 ].…”