From access to reserve: antimicrobial resistance among etiological agents of central line-associated bloodstream infections in the view of WHO's AWaRe antimicrobial spectrum.

Aim: Central line-associated bloodstream infections (CLABSI) remain a major contributor to morbidity and mortality in critically ill patients. The rise of antimicrobial resistance (AMR) exacerbates treatment challenges, making it crucial to examine pathogen resistance patterns. This study analyses CLABSI-associated pathogens' antimicrobial susceptibility using the WHO's AWaRe antimicrobial framework, providing insights to guide targeted treatment and strengthen infection control strategies.

Methods: This observational study (2021-2024) assessed data from adult and pediatric ICUs to evaluate CLABSI incidence, microbial etiology, and antimicrobial susceptibility trends. We categorized antimicrobials based on the WHO's AWaRe classification system, analysing their susceptibility to Access, Watch, and Reserve antimicrobials. Statistical analysis was performed using SPSS version 22.

Results: Among 5,398 patient records, 101 cases of CLABSI were confirmed. The predominant pathogens were Klebsiella (K.) pneumoniae (27.7%), Acinetobacter spp. (19.8%), and Candida spp. (17.8%). A worrying decline in susceptibility to Access- and Watch-category antimicrobials was observed in key pathogens. K. pneumoniae demonstrated a steep decline in susceptibility to Access-category agents, from 27.8% in 2021 to 16.7% in 2023. Conversely, Reserve-category antimicrobials maintained 100% efficacy across the study period. Acinetobacter spp. exhibited resistance to both Access- and Watch-category antimicrobials by 2024. Pseudomonas aeruginosa showed a drastic drop in Watch-category susceptibility, from 44.5% in 2021 to 0% in 2023, while Reserve-agents remained effective. These results underline the growing reliance on Reserve antimicrobials and the diminishing effectiveness of first-line agents. Furthermore, a fluctuation in CLABSI rates was also observed, with a significant reduction in infection rates in 2024 after the implementation of enhanced infection control practices.

Conclusion: This study highlights the escalating resistance patterns of CLABSI pathogens, with a consternating decline in Access- and Watch-category antimicrobial efficacy. The AWaRe framework proves invaluable in identifying critical resistance trends, demonstrating the need for targeted antimicrobial stewardship. Prioritizing Access antimicrobials as first-line therapies, guided by local resistance data, can preserve the effectiveness of Reserve agents. A strategic focus on the AWaRe classification, coupled with rigorous infection control and stewardship programs, is essential to combat the rising AMR threat and optimize patient outcomes in critical care settings.