Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán, México City, México.
J Anim Sci. 2011 Sep;89(9):2926-31. doi: 10.2527/jas.2010-3576. Epub 2011 Mar 31.
Florfenicol administered through the drinking water has been recommended as a metaphylactic antibacterial drug to control outbreaks of respiratory diseases in pigs caused by strains of Actinobacillus pleuropneumoniae and Pasteurella multocida, yet it is difficult to pinpoint in practice when the drug is given metaphylactically or therapeutically. Further, pigs are likely to reject florfenicol-medicated water, and plasma concentrations of the drug are likely to be marginal for diseases caused by Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus. The reported minimal inhibitory concentration (MIC) values for these organisms show a breakpoint of 2 to 3 μg/mL. An experiment was conducted during September and October 2009. One hundred twenty healthy crossbred pigs (Landrace-Yorkshire), weighing 23 ± 6.2 kg, were used in this trial. They were randomly assigned to 5 groups, with 3 replicates of 8 animals/group. Two commercial preparations of florfenicol were administered through the drinking water at 2 concentrations (0.01 and 0.015%). Water intake was measured before and after medication, and plasma concentrations of florfenicol were determined by HPLC. Considerable rejection of florfenicol-medicated water was observed. However, plasma florfenicol concentrations were of a range sufficient for a methaphylaxis approach to preventing disease by bacteria, with MIC breakpoints of ≤ 0.25 μg/mL. Decreased efficacy as a metaphylactic medication should be expected for bacteria with MIC >0.25 μg/mL, considering the reported existence of bacteria resistant to florfenicol and the natural resistance of Streptococcus suis or E. coli to this drug.
通过饮用水给予氟苯尼考已被推荐为一种预防用抗菌药物，以控制由胸膜肺炎放线杆菌和多杀巴斯德氏菌引起的猪呼吸道疾病的爆发，但实际上很难确定何时进行预防用药或治疗用药。此外，猪可能会拒绝饮用含氟苯尼考的水，并且对于由大肠杆菌、肺炎克雷伯菌和金黄色葡萄球菌引起的疾病，氟苯尼考的血浆浓度可能处于边缘状态。这些生物体的报告最小抑菌浓度（MIC）值显示出 2 至 3 μg/mL 的断点。2009 年 9 月至 10 月进行了一项实验。本试验使用了 120 头健康的杂交猪（长白猪-约克夏猪），体重为 23 ± 6.2kg。它们被随机分为 5 组，每组 3 个重复，每组 8 头。通过饮用水以 2 种浓度（0.01 和 0.015%）给予两种市售氟苯尼考制剂。在给药前后测量水的摄入量，并通过 HPLC 测定氟苯尼考的血浆浓度。观察到大量猪拒绝饮用含氟苯尼考的水。然而，氟苯尼考的血浆浓度处于足以预防 MIC 断点≤0.25μg/mL 的细菌疾病的预防用药范围内。考虑到存在对氟苯尼考耐药的细菌以及猪链球菌或大肠杆菌对该药物的天然耐药性，预计对于 MIC>0.25μg/mL 的细菌，其作为预防用药物的疗效会降低。
