A rapid and simple method for routine determination of antibiotic sensitivity to biofilm populations of Pseudomonas aeruginosa

Table 1 Susceptibility range for each of the antibiotics based on planktonic population (MIC) and as a biofilm population (MBEC) derived by the fluorometric-based assay and Calgary Biofilm Device

Antimicrobial agents	Broth microdilution	Fluorometric-based assay		Calgary Biofilm Device
Antimicrobial agents	MIC^a	MBEC-50^b	MBEC-75^b	MBEC
Gentamicin	0.25–16	2–128	4–512	2–512
Amikacin	0.25–64	2–256	2–512	2–512
Ciprofloxacin	0.25–64	0.5–128	1–512	0.5–512
Meropenem	0.25–64	2–256	2–512	2–512
Colistin	0.25–32	1–128	1–256	1–256
Fosfomycin	0.25–256	2–512	2–512	2–512
Ceftazidime	0.25–128	2–512	2–512	2–512

^aMinimal inhibitory concentrations (MIC, mg mL⁻¹) of planktonic cells
^bMinimal biofilm eradication concentrations (MBEC, mg mL⁻¹) were categorized as responsive reaching about 50% and 75% of the total nonviable cells within a given antibiotic concentration range

ISSN: 1476-0711