Yeaman M R, Mitscher L A, Baca O G
Department of Biology, University of New Mexico, Albuquerque 87131.
Antimicrob Agents Chemother. 1987 Jul;31(7):1079-84. doi: 10.1128/AAC.31.7.1079.
Antibiotic susceptibility testing of the rickettsial Q fever agent Coxiella burnetii was performed by using persistently infected L929 fibroblast cells. The efficacies of a variety of antibiotics with different metabolic targets were tested and compared. The most effective antibiotics in bringing about the elimination of the parasite from infected cells included several quinolone compounds and rifampin. Of the quinolone compounds tested, difloxacin (A-56619) was the most effective, followed by ciprofloxacin and oxolinic acid. These three quinolones were apparently rickettsiacidal. After 48 h of exposure to microgram amounts of the compounds (ranging from 2 micrograms of difloxacin per ml to 5 micrograms of the other two antibiotics per ml), the number of intracellular parasites markedly declined; after 10 days of treatment, very few intracellular rickettsiae were detected. Rifampin (1 microgram/ml) was also very effective in eliminating the parasites. Some of the 13 other antibiotics tested that were somewhat effective included chloramphenicol, doxycycline, and trimethoprim. The persistently infected L929 cells were found to provide a convenient system for the relatively rapid determination of the susceptibility of C. burnetii to antibiotics.
利用持续感染的L929成纤维细胞对立克次体Q热病原体贝纳柯克斯体进行了抗生素敏感性测试。测试并比较了多种具有不同代谢靶点的抗生素的疗效。能使感染细胞中的寄生虫被清除的最有效抗生素包括几种喹诺酮类化合物和利福平。在所测试的喹诺酮类化合物中，双氟沙星（A - 56619）最有效，其次是环丙沙星和恶喹酸。这三种喹诺酮类药物显然具有杀立克次体的作用。在暴露于微克量的化合物（从每毫升2微克双氟沙星到每毫升5微克其他两种抗生素）48小时后，细胞内寄生虫数量显著下降；治疗10天后，几乎检测不到细胞内立克次体。利福平（每毫升1微克）在清除寄生虫方面也非常有效。所测试的其他13种抗生素中有些也有一定效果，包括氯霉素、强力霉素和甲氧苄啶。发现持续感染的L929细胞为相对快速测定贝纳柯克斯体对抗生素的敏感性提供了一个便利的系统。
