Antimicrobial susceptibility of Mannheimia haemolytica and Pasteurella multocida isolated from ovine respiratory clinical cases in Spain and Portugal

In this study, the key pharmacodynamic parameter (MIC) was determined for Pasteurella multocida and Mannhaemaia haemolytica isolated from ovine respiratory clinical cases using accepted laboratory methods for bacterial isolation, identification and MIC determination. In the case of Pasteurella multocida, for sulfamethoxazole/trimethoprim, MICrange, MIC50 and MIC90 values were 0.004–32 μg/mL, 0.063 μg/mL and 1 μg/mL; for tetracycline 0.016-256 μg/mL, 1 μg/mL, and 32 μg/mL; for enrofloxacin 0.002–32 μg/mL, 0.016 μg/mL and 0.5 μg/mL; for doxycycline 0.063–32 μg/mL, 1 μg/mL and 16 μg/mL. In the case of Mannhaemia haemolytica for sulfamethoxazole/trimethoprim, MICrange, MIC50 and MIC90 values were 0.004–1024 μg/mL, 0.063 μg/mL and 1 μg/mL; for tetracycline 0.063-256 μg/mL, 8 μg/mL, and 64 μg/mL; for enrofloxacin 0.004–32 μg/mL, 0.032 μg/mL and 16 μg/mL; for doxycycline 0.063–256 μg/mL, 2 μg/mL L and 16 μg/mL. The antimicrobial pattern showed good susceptibility for ovine respiratory pathogens to various licensed antibiotics including fluoroquinolones and sulfonamides. However, the antimicrobial susceptibility of antibiotics in the tetracycline family was variable. Doxycycline showed a better antimicrobial pattern than tetracycline. Finally, antimicrobial susceptibility monitoring programs are recommended to provide evidence-based guidance for antimicrobial therapy of bacterial diseases.

Source: Small Ruminant Research - August 18, 2019 Category: Zoology Source Type: research