AUTHOR=Zhang Longfei , Xie Hongbing , Wang Hongjuan , Ding Huanzhong , Zhang Gaiping , Hu Jianhe 

TITLE=Kill Rate and Evaluation of Ex Vivo PK/PD Integration of Cefquinome Against Actinobacillus pleuropneumoniae

JOURNAL=Frontiers in Veterinary Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.751957

DOI=10.3389/fvets.2021.751957

ISSN=2297-1769

ABSTRACT=<p>We wished to study the detailed and precise antibacterial activity of cefquinome against <italic>Actinobacillus pleuropneumoniae</italic> (APP) <italic>in vitro</italic> and <italic>ex vivo</italic>. We analyzed the relationships between kill rate and cefquinome concentration in broth and between pharmacokinetic/pharmacodynamic (PK/PD) parameters and antibacterial effect in serum and tissue cage fluid (TCF) of piglets. Cefquinome exhibited time-dependent antibacterial activity against APP according to the kill rate. The maximum kill rate was 0.48 log<sub>10</sub> CFU/mL/h at the 0-9-h period in broth. In the <italic>ex vivo</italic> PK/PD study, the maximum concentration (C<sub>max</sub>), time to reach the maximum concentration (T<sub>max</sub>), terminal half-life (T<sub>1/2β</sub>), and area under the concentration time curve (AUC<sub>infinity</sub>) were 5.65 μg/ml, 0.58 h, 2.24 h, and 18.48 μg·h/ml in serum and 1.13 μg/ml, 2.60 h, 12.22 h, and 20.83 μg·h/ml in TCF, respectively. The values of area under the curve during 24 h/minimum inhibitory concentration (AUC<sub>24h</sub>/MIC) for bacteriostatic, bactericidal, and bacterial eradication effects were 18.94, 246.8, and 1013.23 h in serum and 4.20, 65.81, and 391.35 h in TCF, respectively. Our findings will provide a valuable basis for optimization of dosage regimens when applying cefquinome to treat APP infection.</p>