Alt D P, Bolin C A
National Animal Disease Center, USDA, Ames, IA 50010, USA.
Am J Vet Res. 1996 Jan;57(1):59-62.
To evaluate antimicrobial agents for treatment of models of acute and persistent leptospirosis caused by Leptospira interrogans serovar pomona.
Randomized trials comparing dosages and regimens of various antimicrobial agents for treatment of acute and persistent leptospirosis.
245 Golden hamsters to model acute leptospirosis and 121 mixed-breed swine to model persistent leptospirosis.
Hamsters and swine were inoculated with L interrogans serovar pomona. Antimicrobial agents were given to hamsters for 3 or 5 days after inoculation, with necropsy at 14 days after inoculation. Swine were treated for 1, 3, or 5 days beginning at 3 weeks after inoculation, and were necropsied 7 to 10 days after completion of antimicrobial agent treatment. Hamster tissue and swine tissue and urine specimens were examined by culture, fluorescent antibody testing, and histologic examination for presence of leptospires.
All untreated control hamsters became infected and manifested clinical signs and lesions of acute leptospirosis. Leptospires were not detected in hamsters treated with dihydrostreptomycin/penicillin G (25 mg/kg of body weight). Administration of ampicillin at all dosages reduced the number of hamsters infected, as confirmed at necropsy; the other agents tested required dosages greater than label recommendations to reduce the number infected. All untreated control swine became infected and shed leptospires in urine through the time of necropsy. Leptospires were not detected in kidneys or urine of swine treated with dihydrostreptomycin/penicillin G (25 mg/kg) for 1, 3, or 5 days, or in swine treated with oxytetracycline (40 mg/kg for 3 or 5 days), tylosin (44 mg/kg for 5 days), or erythromycin (25 mg/kg for 5 days). Treatment with ceftiofur and ampicillin was not effective in elimination of L interrogans serovar pomona in swine.
Dihydrostreptomycin/penicillin G is effective for treatment of acute and persistent leptospirosis. Differences between the effectiveness of antimicrobial agents in the acute and persistent model of leptospirosis emphasize the importance of using the appropriate model for treatment evaluation. Antimicrobial agents evaluated for treatment of persistent leptospirosis in swine required the use of dosages above those recommended by the manufacturer.
Use of antimicrobial agents at extra-label dosages for treatment of persistent leptospirosis may cause residue problems in food animals; however, these regimens may be useful for treatment of breeding stock or animals destined for import/export.
评估抗菌药物对由波摩那群问号钩端螺旋体引起的急性和持续性钩端螺旋体病模型的治疗效果。
比较各种抗菌药物治疗急性和持续性钩端螺旋体病的剂量和方案的随机试验。
245只金黄仓鼠用于建立急性钩端螺旋体病模型，121头杂种猪用于建立持续性钩端螺旋体病模型。
仓鼠和猪接种波摩那群问号钩端螺旋体。仓鼠在接种后3天或5天给予抗菌药物，接种后14天进行尸检。猪在接种后3周开始治疗1天、3天或5天，抗菌药物治疗结束后7至10天进行尸检。通过培养、荧光抗体检测和组织学检查，检测仓鼠组织、猪组织和尿液标本中钩端螺旋体的存在情况。
所有未治疗的对照仓鼠均被感染，并表现出急性钩端螺旋体病的临床症状和病变。用双氢链霉素/青霉素G（25mg/kg体重）治疗的仓鼠未检测到钩端螺旋体。尸检证实，所有剂量的氨苄西林给药均减少了感染仓鼠的数量；其他受试药物需要高于标签推荐剂量才能减少感染数量。所有未治疗的对照猪均被感染，并在尸检时尿液中排出钩端螺旋体。用双氢链霉素/青霉素G（25mg/kg）治疗1天、3天或5天的猪，或用土霉素（40mg/kg，治疗3天或5天）、泰乐菌素（44mg/kg，治疗5天）或红霉素（25mg/kg，治疗5天）治疗的猪，其肾脏或尿液中均未检测到钩端螺旋体。头孢噻呋和氨苄西林治疗对猪体内波摩那群问号钩端螺旋体的清除无效。
双氢链霉素/青霉素G对急性和持续性钩端螺旋体病有效。抗菌药物在急性和持续性钩端螺旋体病模型中的有效性差异强调了使用适当模型进行治疗评估的重要性。评估用于治疗猪持续性钩端螺旋体病的抗菌药物需要使用高于制造商推荐的剂量。
使用超出标签剂量的抗菌药物治疗持续性钩端螺旋体病可能会在食用动物中引起残留问题；然而，这些方案可能对种畜或进出口动物的治疗有用。
