Pharmacokinetic/Pharmacodynamic Relationships of Tulathromycin Against Actinobacillus pleuropneumoniae in a Porcine Tissue Cage Infection Model

Lihua Yao; Lan Yang; Yuzhou Ling; Yanzhe Wei; Xiangguang Shen; Huanzhong Ding

doi:10.3389/fvets.2022.822432

Pharmacokinetic/Pharmacodynamic Relationships of Tulathromycin Against Actinobacillus pleuropneumoniae in a Porcine Tissue Cage Infection Model

Front Vet Sci. 2022 Mar 28:9:822432. doi: 10.3389/fvets.2022.822432. eCollection 2022.

Authors

Lihua Yao¹, Lan Yang¹, Yuzhou Ling¹, Yanzhe Wei¹, Xiangguang Shen¹, Huanzhong Ding¹

Affiliation

¹ Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.

Abstract

Tulathromycin is a semi-synthetic macrolide antibiotic that is highly effective in treating respiratory tract bacterial infections. We evaluated the in vivo antibacterial activity of tulathromycin against Actinobacillus pleuropneumoniae in piglets and determined its pharmacokinetic/pharmacodynamic (PK/PD) relationships using a tissue cage infection model. A. pleuropneumoniae (10⁸ CFU/ml) was exposed to tulathromycin via intramuscular injection followed by a collection of cage tissue fluids at various intervals. The percentage of time the drug concentration remained above the minimum inhibitory concentration (MIC) divided by the dosing interval (%T > MIC) was the best PK/PD index to describe the antibacterial efficacy of tulathromycin (R ² = 0.9421). The %T > MIC values required to achieve 1 - log₁₀CFU/ml reductions and bactericidal activity (3 - log₁₀CFU/ml reduction) were 50.8 and 96.38%, respectively. These results demonstrated that maintaining %T > MIC above 96.38% achieved bactericidal activity and thereby optimized the clinical dosage.

Keywords: %T > MIC; Actinobacillus pleuropneumoniae; PK/PD relationship; tissue cage infection model; tulathromycin.