Temporal Trends in Antimicrobial Resistance in a Tertiary Hospital in Western Guangxi, China: A Five-Year Surveillance Study (2021-2025).

BACKGROUND

Although antimicrobial resistance (AMR) exhibits substantial regional heterogeneity, data from western Guangxi in Southwest China remain limited. To address this gap, we conducted a five-year surveillance study at a tertiary hospital in this area to characterize pathogen distribution, resistance trends, and discrepancies compared with national benchmarks.

METHODS

All non-duplicate clinical bacterial isolates collected between January 2021, and December 2025 were included. Species identification and antimicrobial susceptibility testing were performed using MALDI-TOF MS and the VITEK 2 system. Results were interpreted according to Clinical and Laboratory Standards Institute (CLSI) criteria. Resistance trends were analyzed using WHONET software, and chi-square tests and trend analyses were applied to evaluate temporal changes and to compare findings with data from the China National Surveillance System (CHINET).

RESULTS

Among 57,157 clinical isolates, Gram-negative bacteria predominated (71.0%), with Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus representing the leading pathogens. ICUs contributed a large share of isolates and showed higher proportions of non-fermentative Gram-negative bacilli and carbapenem-resistant strains, whereas pediatric wards predominantly isolated Haemophilus influenzae and Moraxella catarrhalis. Carbapenem-resistant Escherichia coli (CRECO) and Klebsiella pneumoniae (CRKPN) remained below 5% throughout the study period. In contrast, carbapenem-resistant Pseudomonas aeruginosa (CRPAE) increased from 9.57% in 2021 to 19.96% in 2025. Carbapenem-resistant Acinetobacter baumannii (CRAB) remained highly prevalent (>50% in several years) but declined to 41.53% by 2025. Streptococcus pneumoniae consistently exhibited macrolide resistance rates exceeding 90%. Significant differences compared with CHINET data were observed for CRECO (P=0.043) and CRKPN (P=0.001). The local prevalence of CRECO and respiratory pathogens significantly exceeded national CHINET data, while CRKPN prevalence was comparatively lower.

CONCLUSION

This study describes antimicrobial resistance patterns in a tertiary hospital in western Guangxi, China, with an increasing trend in CRPAE, while CRECO remained below 5% but was relatively higher than that reported in CHINET data, warranting continued surveillance. These findings underscore the essential role of regional surveillance and highlight the need for continued monitoring and strengthened antimicrobial stewardship, particularly in ICU settings and pediatric respiratory infections.