Comparative Minimum Inhibitory and Mutant Prevention Drug Concentrations for Pradofloxacin and Seven Other Antimicrobial Agents Tested against Bovine Isolates of and .

Pradofloxacin-a dual-targeting fluoroquinolone-is the most recent approved for use in food animals. Minimum inhibitory and mutant prevention concentration values were determined for pradofloxacin, ceftiofur, enrofloxacin, florfenicol, marbofloxacin, tildipirosin, tilmicosin, and tulathromycin. For strains, MIC values were ≤0.016/≤0.016/≤0.016 and MPC values were 0.031/0.063/0.063; for strains, the MIC values ≤0.016/≤0.016/0.031 and MPC ≤ 0.016/0.031/0.063 for pradofloxacin. The pradofloxacin C/MIC and C/MPC values for and strains, respectively, were 212.5 and 53.9 and 212.5 and 109.7. Similarly, AUC/MIC and AUC/MPC for were 825 and 209.5, and for they were 825 and 425.8. Pradofloxacin would exceed the mutant selection window for >12-16 h. Pradofloxacin appears to have a low likelihood for resistance selection against key bovine respiratory disease bacterial pathogens based on low MIC and MPC values.