The most common cause of serious bacterial disease in infants under the age of two is now thought to be a febrile UTI. In children, UTI can permanently harm the renal parenchyma, causing chronic renal insufficiency and other issues. Early and efficient antibiotic treatment is crucial to avoiding this danger. Additionally, quick treatment is essential to enhance the patient's clinical state, avoid bacteraemia, and reduce the chance of bacterial localisation in other body sites. However, as bacterial infectionslinked to UTIs become more resistant to antibiotics, recommendations quickly become outdated and determining the optimal empiric antibiotic therapy becomes more challenging. Antibiotic susceptibility of pathogens varies, and this variation is crucial for selecting a treatment that works. Furthermore, the risk of ineffective treatment can be decreased by correctly identifying patients who are more likely to develop difficult-to-treat UTIs
