Broad-spectrum antimicrobial consumption trends and correlation with bacterial infections and antimicrobial resistance over 5 years

Consumption trends of four broad-spectrum antimicrobials and their correlation with antimicrobial resistance in Gram-negative bacilli (GNB) from 2013–2017 within intensive care units (ICUs) were explored. Consumption of meropenem (MEM), polymyxin B (PMB), piperacillin/tazobactam (TZP) and cefepime (FEP) in defined daily doses per 1000 patient-days (DDD/1000PD) was measured. Infection-related GNB isolates were grouped according to specific resistance profiles. Time series of antimicrobial consumption and their parametric correlation with each grouped resistant GNB were explored. A total of 1423 GNB were evaluated. A significant linear decline in consumption was observed for MEM slope –3.88, 95% confidence interval (CI) –4.96 to –2.81; P < 0.0001 and PMB (slope –3.51, 95% CI –5.528 to –1.495; P = 0.0009). A significant decline in MEM-non-susceptible Acinetobacter spp. (R2 = 0.476; P = 0.006) and an increase in FEP-non-susceptible Escherichia coli (R2 = 0.124; P = 0.006) was observed. A significant correlation between MEM consumption and MEM-non-susceptible Acinetobacter spp. (r = 0.43; P = 0.001) was observed. MEM consumption and MEM-non-susceptible Acinetobacter spp. showed a positive correlation. Reduction in the consumption of broad-spectrum antimicrobials may alter the frequency of infection-related isolates and their antimicrobial resistance profiles.