Analysis of the Etiology and Antibiotic Resistance of Bacterial Infections in Newborns in a Chinese Tertiary Hospital: From 2019 to 2024.

OBJECTIVE: This study aims to investigate the pathogen spectrum and antimicrobial resistance trends in hospitalized infants in the neonatal intensive care unit (NICU) of our hospital (a major hospital in China) from 2019 to 2024. The evolving pathogen spectrum highlights the need for precise local diagnostic strategies based on surveillance data. The high prevalence of antimicrobial resistance calls for the optimization of empirical antimicrobial therapy and stringent antimicrobial stewardship. Additionally, this study provides evidence-based recommendations for cost-effective antimicrobial resistance control in resource-limited regions globally. METHODS: A retrospective analysis of neonatal infection clinical data from the past five years was performed, focusing on the distribution of major pathogens and the evolution of antimicrobial resistance across the years. RESULTS: A total of 566 distinct pathogens were isolated from 523 neonatal bacterial infection cases. Gram-positive bacteria represented the largest proportion (56.5%), with Staphylococcus aureus being the most common (173 strains, 30.6%). It demonstrated the highest resistance to penicillin (86.1%) and a relatively high resistance to erythromycin (52.6%), while remaining 100% sensitive to vancomycin, linezolid, and tigecycline. Staphylococcus epidermidis exhibited significant resistance to benzathine penicillin (75.3%) and erythromycin (62.3%), with a positive rate of 77.9% in the cefotaxime screening test. The proportion of Gram-negative bacteria was 43.5%. Among the Gram-negative pathogens, Escherichia coli showed high resistance (80.0-86.1%) to cefoperazone-sulbactam and other β-lactams but only 0.9% resistance to carbapenems and full sensitivity to amikacin. Klebsiella pneumoniae exhibited significant resistance, with 34.1% of strains resistant to carbapenems. CONCLUSION: Over the past five years, Gram-positive bacteria have remained the predominant pathogens in NICU infections, with detection rates increasing annually. In contrast, the detection rate of Gram-negative bacteria has decreased. Gram-positive bacteria show high resistance to penicillin, while Gram-negative bacteria exhibit high resistance to third-generation cephalosporins. Additionally, multidrug-resistant strains have been identified. Temporal trend analysis revealed significant increasing trends for S. aureus (P=0.027) and S. epidermidis (P=0.038), and significant decreasing trends for E. coli (P=0.016).