Prevalence and Antimicrobial Resistance of Klebsiella pneumoniae Infections in Children: A Ten-year Retrospective Study at a Tertiary Hospital in Guangzhou, China

Purpose: To investigate the clinical distribution and resistance trends of Klebsiella pneumoniae (KP) among pediatric patients at a tertiary pediatric hospital in Guangzhou, China (2015– 2024), with a focus on extended-spectrum β-lactamase-producing (ESBL-KP) and carbapenem-resistant (CRKP) strains. Patients and Methods: A retrospective analysis was performed on non-duplicate KP isolates obtained from pediatric patients (aged ≤ 14 years) at Guangdong Women and Children Hospital (2015– 2024). Time trends of isolated rates and resistance rates for the KP strains were analyzed using Joinpoint regression, with statistical analysis performed in SPSS and Python. Results: A total of 2907 non-duplicate KP isolates from 2557 patients were analyzed. The proportion of KP among all clinical isolates decreased significantly from 18.4% (492/2670) in 2015 to 6.5% (203/3135) in 2024 ( P < 0.05), with the highest proportion (49.0%,1254/2258) observed in infants aged ≤ 1 month. The KP strains were most often cultured from lower respiratory tract specimens (70.8%, 2059/2907), followed by blood (10.0%, 292/2907) and urine specimens (7.8%, 227/2907). The strains showed two peaks of third- generation cephalosporin resistance in 2018 (64.3% [231/359] for ceftriaxone, 52.1% [215/498] for ceftazidime) and 2023 (42.0% [55/131] for ceftriaxone, 34.1% [45/132] for ceftazidime), and the highest resistance rates of carbapenems were 20.8% (97/466) in 2016. The proportion of ESBL-KP among all KP isolates decreased from 54.3% (266/490) to 29.1% (59/203) ( P < 0.05). ESBL-KP isolates were found more frequently in blood and urine. The proportion of CRKP remained stable (7.5% [37/492] to 7.9% [16/203]; P > 0.05). CRKP was mainly found in ICU wards. CRKP rates dropped from 67.6% (25/37) to 0% (0/16) in the neonatal intensive care unit (NICU) but increased from 10.3% (4/39) to 50.0% (8/16) in the pediatric intensive care unit (PICU). Patients infected with ESBL-KP or CRKP were associated with significantly longer hospital stays compared to those caused by non-multidrug-resistant strains ( P < 0.05). Conclusion: Despite a decreasing overall prevalence of KP, the persistent high prevalence of ESBL-KP and the rapidly increasing trend of CRKP in the PICU suggested that recalibrated, unit-specific antimicrobial strategies were necessary. This study provides supporting information for the rational use of antimicrobial agents in clinical practice based on the comprehensive investigation of antimicrobial resistance change.