Matsushita S, Suzuki E
Section of Laboratory Animals, National Institute of Radiological Sciences, Chiba, Japan.
Lab Anim Sci. 1995 Oct;45(5):503-7.
The effects of continuous oral administration of antibiotics in mice were investigated. Sulfamerazine, ampicillin, and chlortetracycline were tested at a rate of 500 mg/L of drinking water. Mice were infected by intranasal inoculation with 10(6) bacilli of the SMR strain of cilia-associated respiratory (CAR) bacillus. The mice were treated with the antibiotics starting 1 week before, 1 week after, or 4 weeks after the inoculation, for 5, 3, or 4 weeks respectively, then were examined. The infected mice lost body weight, and this loss was prevented or regained by all of the antibiotic treatments. Serologically no antibodies were detectable in the mice administered sulfamerazine starting 1 week before the inoculation. Mice administered sulfamerazine starting 1 week after the inoculation and ampicillin or chlortetracycline starting 1 week before or after the inoculation yielded a low titer of antibodies compared with nontreated infected mice. Mice administered antibiotics starting 4 weeks after the inoculation yielded the same titer of antibodies as nontreated infected mice. No pathologic respiratory tract lesions were observed in mice administered sulfamerazine starting 1 week before the inoculation. Mice administered sulfamerazine starting 1 week after the inoculation or ampicillin starting 1 week before or after the inoculation had slight peribronchitis without CAR bacillus colonization. Mice administered chlortetracycline, starting either 1 week before or after inoculation, developed peribronchitis, with colonization of the bacillus on the airway mucosa. In mice medicated starting 4 weeks after the inoculation, respiratory tract lesions developed, but their severity was reduced. The airway mucosa in mice treated with chlortetracycline was associated with the CAR bacillus but not in mice treated with sulfamerazine and ampicillin. These findings suggest that prevention and eradication of CAR bacillus infection is possible by treatment with sulfamerazine.
研究了连续口服抗生素对小鼠的影响。以500毫克/升的饮水浓度测试了磺胺间二甲氧嘧啶、氨苄青霉素和金霉素。通过鼻内接种10(6) 株纤毛相关呼吸道（CAR）杆菌的SMR菌株杆菌感染小鼠。分别在接种前1周、接种后1周或接种后4周开始用抗生素治疗小鼠，持续5周、3周或4周，然后进行检查。感染的小鼠体重减轻，而所有抗生素治疗均能防止体重减轻或使其恢复。在接种前1周开始给予磺胺间二甲氧嘧啶的小鼠中，血清学上未检测到抗体。与未治疗的感染小鼠相比，在接种后1周开始给予磺胺间二甲氧嘧啶以及在接种前或接种后1周开始给予氨苄青霉素或金霉素的小鼠产生的抗体滴度较低。在接种后4周开始给予抗生素的小鼠产生的抗体滴度与未治疗的感染小鼠相同。在接种前1周开始给予磺胺间二甲氧嘧啶的小鼠中未观察到病理性呼吸道病变。在接种后1周开始给予磺胺间二甲氧嘧啶或在接种前或接种后1周开始给予氨苄青霉素的小鼠有轻微的支气管炎，无CAR杆菌定植。在接种前或接种后1周开始给予金霉素的小鼠发生了支气管炎，杆菌在气道黏膜定植。在接种后4周开始用药的小鼠中出现了呼吸道病变，但其严重程度有所减轻。用金霉素治疗的小鼠气道黏膜与CAR杆菌有关，而用磺胺间二甲氧嘧啶和氨苄青霉素治疗的小鼠则无关。这些发现表明，用磺胺间二甲氧嘧啶治疗可预防和根除CAR杆菌感染。
