Biofilm Eradication Concentrations of Antibiotics

The minimum biofilm eradication concentration (MBEC) values of levofloxacin, amikacin, meropenem, tigecycline, colistin and cefepime in A. baumannii isolates were measured using the broth microdilution method. First, the isolates were cultivated in the sterile 96-well polystyrene microtiter plates for an overnight at 37°C to allow for the biofilm formation. The biofilms were then exposed to the concentrations of 2 to 4096 µg/mL of levofloxacin, 4 to 8192 µg/mL of amikacin, 2 to 4096 µg/mL of meropenem, 0.5 to 2048 µg/mL of tigecycline and 16 to 16,384 µg/mL of cefepime for an overnight at 37°C. Then, the wells were washed with sterile PBS three times, and incubated with Muller Hinton Broth (Merck, Germany) for an overnight at 37°C. The MBEC was proposed as any viable cell was not recovered from the biofilm material or i.e. OD₅₇₀ was less than 0.1. All tests were repeated in triplicate.21 (link)