Lee Oh Hyun, Baek Ji Hyeon, Lee Jin-Soo, Chung Moon-Hyun, Lee Sun Myoung, Kang Jae-Seung
Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea.
Translation Research Center, Inha University School of Medicine, Incheon, Korea.
Infect Chemother. 2014 Sep;46(3):189-93. doi: 10.3947/ic.2014.46.3.189. Epub 2014 Sep 24.
We have investigated the in vitro antimicrobial effects of antibiotic combinations against Orientia tsutsugamushi, the causative agent of scrub typhus. ECV304 cells were infected with the Boryong strain of O. tsutsugamushi and incubated in a medium containing doxycycline (4 µg/mL), azithromycin (0.5 µg/mL), rifampin (4 µg/mL), ciprofloxacin (25 µg/mL), gentamicin (5 µg/mL), cefotaxime (2 µg/mL), or combinations of these agents for 7 days, after which immunofluorescent staining for O. tsutsugamushi was performed. The percentages of infective foci in cultures containing antibiotics compared to those in cultures without antibiotics were 6.2% for doxycycline, 9.6% for azithromycin, 8.8% for rifampin, 96.6% for cefotaxime, 29.7% for doxycycline plus cefotaxime, 23.6% for azithromycin plus cefotaxime, and 41.4% for rifampin plus cefotaxime. These findings show an in vitro antagonism between anti-rickettsial agents and cefotaxime against O. tsutsugamushi. These results suggest that the efficacy of antibiotic combinations involving cefotaxime for the treatment of patients with scrub typhus, particularly those with severe pneumonia, needs to be investigated.
我们研究了抗生素组合对恙虫病东方体（恙虫病的病原体）的体外抗菌作用。用恙虫病东方体的浦项株感染ECV304细胞，并在含有强力霉素（4μg/mL）、阿奇霉素（0.5μg/mL）、利福平（4μg/mL）、环丙沙星（25μg/mL）、庆大霉素（5μg/mL）、头孢噻肟（2μg/mL）或这些药物组合的培养基中培养7天，之后对恙虫病东方体进行免疫荧光染色。与不含抗生素的培养物相比，含抗生素培养物中感染灶的百分比分别为：强力霉素6.2%、阿奇霉素9.6%、利福平8.8%、头孢噻肟96.6%、强力霉素加头孢噻肟29.7%、阿奇霉素加头孢噻肟23.6%、利福平加头孢噻肟41.4%。这些发现表明抗立克次体药物与头孢噻肟对恙虫病东方体存在体外拮抗作用。这些结果提示，涉及头孢噻肟的抗生素组合治疗恙虫病患者，尤其是重症肺炎患者的疗效需要进行研究。
