ETIOLOGY OF URINARY TRACT INFECTIONS IN NEONATES AND BACTERIAL RESISTANCE IN CROATIA.

Urinary tract infection (UTI) occurs in approximately 15% of full-term neonates and 8% of those born before 37 weeks of gestation. Severe UTI can lead to sepsis or long-term complications such as renal scarring and hypertension. Given the rising concern of bacterial resistance to antibiotics, this research aimed to examine the epidemiology of neonatal UTI, most common antibiotic prescription patterns, as well as resistance of the causative agents in Croatia. This retrospective multicenter analysis was focused on neonates born in 2005 and 2015. Of the 103 bacterial UTI cases, 78.6% affected term neonates. Male neonates constituted 62.1% of the study population. Eutrophic neonates accounted for 87.4%, and hospital-acquired infections were prevalent in 47.6% of cases. The main causative pathogens were Escherichia coli (60.2%) and Klebsiella pneumoniae (28.2%). Most commonly prescribed empirical antibiotics included ceftriaxone (31.1%) and the ampicillin-gentamicin combination (10.7%). In 2005, 72.7% of isolates were sensitive to empirical therapy. In 2015, sensitivity to empirical antibiotic therapy was observed in 75.6% of cases. In this study, Escherichia coli frequently exhibited antibiotic resistance to ampicillin, amoxicillin, trimethoprim-sulfamethoxazole, and gentamicin. For UTIs attributed to Klebsiella pneumoniae, the prevailing bacterial resistance was observed against gentamicin, ceftibuten, ampicillin, cefazolin, and piperacillin. The predominance of Escherichia coli as the most common pathogen causing UTI was consistent with global trends. Founded on continuous differences in bacterial resistance, this study can serve as a basis for comprehending local resistance patterns of pathogens causing neonatal UTI, highlighting the need of additional prospective research.