Hammerschlag M R
Rev Infect Dis. 1982 Mar-Apr;4(2):500-5. doi: 10.1093/clinids/4.2.500.
With use of a technique for cell culture, the minimal inhibitory concentration (MICs) of trimethoprim (TMP) and sulfamethoxazole (SMZ), alone and in combination at ratios of 1:1, 1:5, and 1:20, were determined against five strains of Chlamydia trachomatis. The drugs were added to idoxuridine-treated McCoy cells after inoculation of the cells with the pathogen. Cultures were examined after incubation for 48 hr; the MIC was defined as the highest concentration of drugs at which no inclusions were seen. Definite end points were observed only with inocula of less than or equal to 10(3) inclusion-forming units (IFU)/ml. With larger inocula, inclusions were present for all dilutions tested. The MICs for TMP alone were greater than or equal to 64 micrograms/ml for all strains. The MICs for SMZ alone ranged from 2 to 128 micrograms/ml. There appeared to be no better than an additive effect for all combinations of TMP and SMZ tested, although the effect of 1:20 was greater than that at 1:1 or 1:5. With increasing concentrations of both drugs, the inclusions became progressively fewer, smaller, and pyknotic. Even though definite end points could not be determined, there was a significant reduction in the number of IFU/ml at relatively low concentrations of both TMP and SMZ. The results of this study suggest that the activity of TMP-SMZ against C. trachomatis is primarily that of SMZ alone.
运用细胞培养技术，测定了甲氧苄啶（TMP）和磺胺甲恶唑（SMZ）单独以及以1:1、1:5和1:20的比例联合使用时对五株沙眼衣原体的最低抑菌浓度（MIC）。在用病原体接种细胞后，将药物添加到经碘苷处理的 McCoy 细胞中。培养48小时后检查培养物；MIC被定义为未见包涵体的最高药物浓度。仅在接种量小于或等于10³包涵体形成单位（IFU）/ml时观察到明确的终点。接种量较大时，所有测试稀释度均有包涵体存在。所有菌株单独使用TMP时的MIC大于或等于64微克/毫升。单独使用SMZ时的MIC范围为2至128微克/毫升。尽管1:20比例的效果大于1:1或1:5比例的效果，但对于所测试的TMP和SMZ的所有组合，似乎都没有比相加作用更好的效果。随着两种药物浓度的增加，包涵体逐渐减少、变小且固缩。尽管无法确定明确的终点，但在相对较低浓度的TMP和SMZ下，IFU/ml的数量有显著减少。本研究结果表明，TMP-SMZ对沙眼衣原体的活性主要是SMZ单独的活性。
