Urinary tract infections (UTI) are among the most common infectious diseases and the most frequent source of community, healthcare-associated and nosocomial bacteraemia. They are associated with significant morbidity and mortality. Due to the high frequency of UTI, they have a major impact on antibiotic use and the antimicrobial resistance of prominent UTI pathogens is of recognised importance. Therefore, UTIs, and particularly complicated urinary tract infections cUTIs, are a target for repurposing of old and neglected drugs, new drug development and non-antibiotic therapeutic and preventive approaches.

Inclusion Criteria:

• A documented microbial pathogen on culture of blood OR urine according to standards of interpretation regarding to the type of infection, pathogen, quantitative culture results and sample. Guide for adequate interpretation is detailed in Lab Manual. However, if the local laboratory uses diferent microbiological criteria, patients will be elegible and the criteria used will be collected AND
• Local and systemic signs and symptoms of UTI including at least one of these two: (a) fever (i.e.,temperature greater than 38ºC), chills or malaise; and (b) flank pain, back pain, costo-vertebral angle pain or tenderness, dysuria or urinary urgency, AND
• It occurs in the presence of a functional or anatomical abnormality of the urinary tract or in the presence of catheterization, including (but not limited to) presence of a urinary catheter; 100 mL or more of residual urine after voiding (neurogenic bladder); obstructive uropathy (nephrolithiasis, fibrosis); azotemia caused by intrinsic renal disease; urinary retention, including retention caused by benign prostatic hypertrophy.
• Patients with pyelonephritis or bacteremia with a urinary tract source, regardless of underlying abnormalities of the urinary tract, are also to be included.
• Patients with urinary catheter presenting with fever, bacteriuria and bacteraemia caused by the same urinary pathogen can be included if other sources of bacteraemia are reasonably discarded.
• Depending on the country regulation: The patient, family or legally authorised representative signed the informed consent to participate or; notification of non-objection to the use of pseudo-anonymized personal and medical data.

Exclusion Criteria:

• Patients with a life expectancy previous to development of cUTI <30 days and those exclusively under palliative care in whom any eventually needed invasive procedure would not be performed.
• Patients who died in <48 hours since the presentation with cUTI
• Patients participating in RCT for treatment of cUTI
• >96 hours since from the clinical diagnosis of cUTI. I.e. >96 hours from positive urine/blood culture.

Adult (≥18 years) patients admitted to an acute care hospital with cUTI, or developing cUTI during hospital stay