Son Dongwook, Chung Moon-Hyun
Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
Infect Chemother. 2014 Sep;46(3):182-8. doi: 10.3947/ic.2014.46.3.182. Epub 2014 Sep 24.
To investigate whether chloroquine enhances the effect of antibiotics against Orientia tsutsugamushi, the causative organism of scrub typhus, we compared the effect of antibiotics in combination with chloroquine with the effect of antibiotics alone in vitro.
The Boryong or AFSC-4 strain was inoculated into ECV304 cells, and incubated in medium containing doxycycline (4 µg/mL), rifampin (4 µg/mL), azithromycin (0.5 µg/mL), chloroquine (1 µg/mL), and each of these antibiotics in combination with chloroquine for 7 d. Immunofluorescence (IF) staining for O. tsutsugamushi was performed 4 hr and 7 d after inoculation of the bacteria, and IF-positive foci were enumerated.
Chloroquine inhibited the growth of O. tsutsugamushi by 15.5%. In combination with chloroquine, the antimicrobial effects increased by 4.4% for doxycycline (a 92.9% reduction of bacterial numbers for doxycycline versus a 97.3% reduction for doxycycline plus chloroquine), 4.6% for rifampin (90.0% versus 94.6%), and 8.3% for azithromycin (86.9% versus 95.2%). The antimicrobial effect of the antibiotics alone was significantly different compared to the combined effect of antibiotics and chloroquine (Wilcoxon signed-rank test, P = 0.001).
The combined use of chloroquine with an antibiotic for the treatment of O. tsutsugamushi infections may be useful for increasing the efficacy of the antibiotics.
为了研究氯喹是否能增强抗生素对恙虫病东方体（恙虫病的病原体）的作用，我们在体外比较了抗生素与氯喹联合使用的效果和单独使用抗生素的效果。
将浦项或AFSC - 4菌株接种到ECV304细胞中，并在含有强力霉素（4μg/mL）、利福平（4μg/mL）、阿奇霉素（0.5μg/mL）、氯喹（1μg/mL）以及这些抗生素与氯喹联合使用的培养基中培养7天。在接种细菌后4小时和7天对恙虫病东方体进行免疫荧光（IF）染色，并对IF阳性病灶进行计数。
氯喹抑制恙虫病东方体生长15.5%。与氯喹联合使用时，强力霉素的抗菌效果提高了4.4%（强力霉素单独使用时细菌数量减少92.9%，与强力霉素加氯喹联合使用时细菌数量减少97.3%相比），利福平提高了4.6%（90.0%对94.6%），阿奇霉素提高了8.3%（86.9%对95.2%）。单独使用抗生素的抗菌效果与抗生素和氯喹联合使用的效果相比有显著差异（Wilcoxon符号秩检验，P = 0.001）。
氯喹与抗生素联合用于治疗恙虫病东方体感染可能有助于提高抗生素的疗效。
