Clinical Characteristics and Antimicrobial Resistance Trends in Neonatal Urinary Tract Infections: A Four-Year Retrospective Analysis and Clinical Implications

Objective: To investigate the clinical characteristics, pathogen distribution, and antibiotic resistance trends of neonatal urinary tract infections (UTIs), providing a basis for clinical diagnosis and treatment. Methods: A retrospective analysis was conducted on the clinical data of 82 neonates diagnosed with UTI in the NICU, including clinical manifestations, laboratory findings, and pathogen distribution. Results: Among 82 neonates with UTI, 59 were male and 23 were female, yielding a male-to-female ratio of 2.57:1. Of these, 9 were early neonatal infections and 73 were late neonatal infections; 65 were full-term and 17 were preterm. The main clinical manifestations included fever (52 cases), jaundice (48 cases), and lethargy (35 cases). All 82 enrolled neonates exhibited elevated urinary leukocytes (>5 per high power field), with 35 cases testing positive for nitrites, 42 for urinary protein (+ to +++), and 28 for positive urinary occult blood. Regarding blood tests, 58 cases showed an increased neutrophil percentage, and 18 cases had thrombocytopenia. Inflammatory markers revealed elevated CRP (>8 mg/L) in 48 cases, elevated PCT (>0.5 ng/mL) in 22 cases, and increased ESR in 38 cases. Ultrasound abnormalities were found in 28 neonates. Urine culture was positive in 68 cases, identifying 75 strains of pathogens, including 46 Gram-negative bacteria, 24 Gram-positive bacteria, and 5 fungi. Conclusion: Neonatal UTIs were more commonly observed in males and generally lacked specific clinical manifestations. Gram-negative bacteria were the main pathogens, with antimicrobial resistance rates remaining high and showing an increasing trend over the four-year period. This study systematically characterizes the four-year temporal trends in antimicrobial resistance patterns among neonatal UTI pathogens in Northeast China. Based on these trends, an evidence-based antibiotic selection strategy was developed, offering valuable guidance for clinical decision-making.