P-1689. Impact of Antibiotic Usage on Antimicrobial Resistance Rates among Gram-Negatives at a COVID-Care Facility

Abstract Background Antimicrobial resistance is directly associated with antimicrobial use and abuse, becoming an important public health problem in modern practice. Unchecked prescriptions, noncompliance with antimicrobial stewardship programs, pandemics, and outbreaks contribute to this issue. This study aims to analyze the antimicrobial resistance patterns over the years in a tertiary-level facility compared to antibiotic usage. E. coli antimicrobial resistance rates and antibiotic usage Methods A retrospective single-center study from 2019 to 2022 was conducted at the Intensive Care Unit of Hospital San Jose, Monterrey, Mexico. Antibiotic usage was calculated using a defined daily dose (DDD) in g/100 beds for Cefepime, Ceftazidime, Ceftriaxone, Ertapenem, Levofloxacin, Meropenem, and Piperacillin/tazobactam. Antimicrobial resistance rates to these antibiotics by Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa isolates from ICU were calculated and compared against antibiotic usage over the years. P. aeruginosa antimicrobial resistance rates and antibiotic usage Results During COVID-19 pandemic in 2020, there was an increased resistance rate of E. coli to cephalosporins (ceftriaxone 80%, ceftazidime 80% and cefepime 80%) in comparison to 2019 and the following years. Klebsiella pneumoniae had a similar behavior, with high resistance rates to cephalosporins (60% each). Pseudomonas aeruginosa isolates also presented a higher resistance rate in 2020 to cefepime (49.6%), ceftazidime (41.6%), meropenem(57.4%) and piperacillin-tazobactam(31.2%) during 2020. During the same year, high DDDs were observed for ceftriaxone (53.3) and meropenem (32.79). Nonetheless, resistance rates to meropenem by P. aeruginosa in 2019 and 2020 (60, 57.4%), E. coli (5.6, 4.4%) and K. pneumoniae (26.3, 7.4%) were not influenced by overuse of meropenem, neither during COVID-19 or the following years. K. pneumoniae antimicrobial resistance rates and antibiotic usage Conclusion Besides overuse of Beta-lactam antibiotics such as ceftriaxone and meropenem during the COVID-19 pandemic, surpassing importantly recommended DDDs by the WHO, resistance rates to these antibiotics in the following years was not affected. Multidisciplinary teams including an infectious disease specialist were fundamental for antimicrobial stewardship during the pandemic, positively impacting resistance rates of Gram-negatives. Disclosures All Authors: No reported disclosures