Impact of restriction of cefepime use on the antimicrobial susceptibility of Gram-negative bacilli related to healthcare-associated infections in an orthopedic hospital Priscila R Oliveira1, Adriana P Paula1, Karine Dal-Paz1, Cassia S Felix1, Flavia Rossi2, Jorge S Silva1, Ana Lucia M Lima11Orthopaedics and Traumatology Department, 2Pathology Department, University of São Paulo, São Paulo, BrazilIntroduction: In recent decades, antimicrobial resistance has become a public health problem, particularly in cases of healthcare-associated infections. Interaction between antibiotic consumption and resistance development is of particular interest regarding Gram-negative bacilli, whose growing resistance has represented a great challenge.Objective: Assess the impact of restriction of cefepime use on antimicrobial susceptibility among the Gram-negative bacilli (GNB) most frequently involved in healthcare-associated infections (HAI).Methods: Data relating to hospital occupancy and mortality rates, incidence of HAI, incidence of GNB as causative agents of HAI, antimicrobial consumption at the hospital and antimicrobial susceptibility of GNB related to HAI were compared between two periods: a 24-month period preceding restriction of cefepime use and a 24-month period subsequent to this restriction.Results: There was a significant drop in cefepime consumption after its restriction. Susceptibility of Acinetobacter baumanii improved relating to gentamicin, but it worsened in relation to imipenem, subsequent to this restriction. For Pseudomonas aeruginosa, there was no change in antimicrobial susceptibility. For Klebsiella pneumoniae and Enterobacter spp, there were improvements in susceptibility relating to ciprofloxacin.Conclusion: Restriction of cefepime use had a positive impact on K. pneumoniae and Enterobacter spp, given that after this restriction, their susceptibilities to ciprofloxacin improved. However, for A. baumanii, the impact was negative, given the worsening of susceptibility to imipenem.Keywords: ecological studies, cross infection, drug resistance, microbial, Gram-negative bacilli, cefepime