Epidemiological and Clinical Insights into Acinetobacter baumannii: A Six-Year Study on Age, Antibiotics, and Specimens

Abstract

Background This six-year retrospective study provides an in-depth analysis of the epidemiological and clinical patterns associated with Acinetobacter baumannii ( A. baumannii ) infections, focusing on age distribution, antibiotic resistance profiles, and specimen types. Aim The research examines the incidence and characteristics of both non-Multi-Drug Resistant (non-MDR) and Multi-Drug Resistant (MDR) A. baumannii strains by reviewing patient records from January 2016 to December 2022. Methods Through a statistical analysis, the study highlights the incidence rates across diverse age groups and explores the impact of antibiotic treatment regimens on infection outcomes. Additionally, it identifies the primary clinical specimen types for each strain, noting an association between non-MDR A. baumannii and midstream urine samples, while MDR A. baumannii strains were more frequently found in respiratory, wound, peripheral, and central line swaps/specimens. Results The results indicate that in 2016, non-MDR A. baumannii infections were notably more frequent compared to MDR A. baumannii cases. However, a significant shift occurred in 2021 and 2022, with a marked decrease in non-MDR A. baumannii cases and an increase in MDR A. baumannii infections. Antibiotic susceptibility testing revealed that non-MDR strains were commonly tested against cefazolin, ceftazidime, ciprofloxacin, gentamicin, nitrofurantoin, oxacillin, piperacillin/tazobactam, and trimethoprim/sulfamethoxazole. In contrast, MDR strains were frequently tested against amikacin, cefepime, colistin, meropenem, imipenem, and tigecycline. Conclusion This study enhances the understanding of A. baumannii clinical behaviour and resistance patterns, offering valuable insights to support future research and inform strategies for infectious disease management and control.