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Breakpoint to MIC quotient: A parameter to rapidly evaluate the in vitro bactericidal activity of β-lactams on Enterobacteriaceae

Antoine Grillon, Angeline Chabaud, Gilles Zambardi, Isabelle Caniaux, François Jehl
International journal of antimicrobial agents 2019 v.53 no.5 pp. 674-677
Enterobacteriaceae, antibacterial properties, antibiotic resistance, antibiotics, bacterial infections, beta-lactams, minimum inhibitory concentration, pathogens, patients, risk
Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) do not completely predict the bactericidal nature of the antimicrobial agent. Patients with pathogens having MICs near the clinical breakpoint experience a higher risk of clinical failure. This study defined an indicator, breakpoint to MIC quotient (BMQ), that incorporates MIC and the European Committee on Antimicrobial Susceptibility Testing breakpoint. The BMQ was inversely correlated with MBC in antibiotic combinations against Enterobacteriaceae strains (Spearman coefficient ≤ –0.96). This new parameter may provide timely additional insight for choosing an antibiotic for a severe bacterial infection.