Conclusion
The method with the CCM 8467 strain of Y. ruckeri showed a higher sensitivity to flumequine than the method with the ATCC 11303 strain of E. coli.
Material and methods
Optimum method conditions were set: cell concentration in the test agar at the level of 9.105-106 CFU/mL, discs with a diameter of 12.7 mm, Antimicrobial Inhibitor Test Agar with a pH of 6.0, and incubation at 30°C for at least 18 h and up to 24 h.
Methods
Optimum method conditions were set: cell concentration in the test agar at the level of 9.105-106 CFU/mL, discs with a diameter of 12.7 mm, Antimicrobial Inhibitor Test Agar with a pH of 6.0, and incubation at 30°C for at least 18 h and up to 24 h.
Results
With respect to the maximum residue limit (MRL), the Y. ruckeri plate method demonstrated the lowest sensitivity to flumequine. The CCβ of the method for flumequine was in the concentration of 100 μg/L-1 (twice the MRL). The study also confirmed that the method exhibits very good sensitivity to the other tested fluoroquinolones, which were marbofloxacin (30 μg/L, 0.4 MRL), ciprofloxacin (10 μg/L, 0.1 MRL), and enrofloxacin (20 μg/L, 0.2 MRL), but lower sensitivity to danofloxacin (42 μg/L, 1.4 MRL).