Armstrong David G, Stephan Kevin T, Espensen Eric H, Lipsky Benjamin A, Boulton Andrew J M
Department of Surgery, Southern Arizona Veterans Affairs Health Care System, Tucson, AZ 85723, USA.
J Foot Ankle Surg. 2003 Sep-Oct;42(5):302-4. doi: 10.1016/s1067-2516(03)00307-7.
This pilot study was undertaken to evaluate the short-term in vitro antimicrobial stability of both vancomycin- and tobramycin-impregnated calcium sulfate pellets mixed and stored in a clinical setting. Powdered tobramycin sulfate (500 mg) and vancomycin hydrochloride (500 mg) were blended into separate basins containing 25 g of surgical-grade calcium sulfate powder, then mixed with 8 mL of sterile saline. From this admixture, 6.0-mm pellets were produced. These were removed from the sterile container (stored at room temperature) at 1, 7, 30, 60, 90, and 120 days and tested against a variety of pathogenic bacterial isolates by using a modification of the standardized Kirby-Bauer test. Control pellets containing no antibiotic were also evaluated. There was no inhibition of bacterial growth by the non-antibiotic-impregnated (control) pellets. There was no appreciable difference in the zones of inhibition for any of the organisms with pellets stored for 1, 7, 30, 60, 90, or 120 days. Zones of inhibition for the various antibiotics to the strain of organism tested ranged from 17 mm to 30 mm, depending on the pathogenic isolate and the antibiotic evaluated. The zones of inhibition observed were similar to those designating antibiotic susceptibility in the Kirby-Bauer test. The results of this preliminary study suggest that clinician-mixed calcium sulfate pellets containing either vancomycin or tobramycin, when stored under normal room temperature and ambient humidity, appear to maintain their antimicrobial characteristics for at least 120 days.
本前瞻性研究旨在评估在临床环境中混合并储存的万古霉素和妥布霉素浸渍硫酸钙微丸的短期体外抗菌稳定性。将硫酸妥布霉素粉末（500mg）和盐酸万古霉素（500mg）分别混入含有25g外科级硫酸钙粉末的盆中，然后与8mL无菌盐水混合。从该混合物中制成6.0mm的微丸。在第1、7、30、60、90和120天从无菌容器（室温储存）中取出这些微丸，并通过改良的标准化 Kirby-Bauer 试验对多种病原菌分离株进行测试。还评估了不含抗生素的对照微丸。未浸渍抗生素的（对照）微丸对细菌生长没有抑制作用。对于储存1、7、30、60、90或120天的微丸，任何生物体的抑菌圈没有明显差异。根据所测试的病原菌和评估的抗生素，各种抗生素对受试菌株的抑菌圈范围为17mm至30mm。观察到的抑菌圈与 Kirby-Bauer 试验中指示抗生素敏感性的抑菌圈相似。这项初步研究的结果表明，临床医生混合的含有万古霉素或妥布霉素的硫酸钙微丸，在正常室温及环境湿度下储存时，似乎至少120天内保持其抗菌特性。
