Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; National Health Research Institute, Chu-Nan, Taiwan.
J Microbiol Immunol Infect. 2015 Oct;48(5):545-51. doi: 10.1016/j.jmii.2014.02.002. Epub 2014 Mar 21.
The emergence of carbapenem-resistant Acinetobacter baumannii (CRAB) complex has posed a great challenge to clinicians worldwide. Sitafloxacin has been shown to have in vitro activity against pathogens resistant to other fluoroquinolones. However, data comparing the anti-CRAB activity of sitafloxacin with that of other antimicrobial agents are limited.
Genospecies were identified by 16S-23S ribosomal RNA intergenic spacer sequencing. Minimum inhibitory concentrations (MICs) were determined by an agar dilution method. Isolates with sitafloxacin MICs ≤ 2 mg/L were provisionally considered as susceptible to sitafloxacin. The MIC breakpoint for tigecycline susceptibility was 2 mg/L.
A total of 167 CRAB complex blood isolates (146 A. baumannii, 7 Acinetobacter pittii, and 14 Acinetobacter nosocomialis) were collected from January 2009 to December 2011. Around 90% of the A. baumannii isolates were resistant to amikacin, cefepime, ceftazidime, piperacillin/tazobactam, ampicillin/sulbactam, ciprofloxacin, and levofloxacin. By contrast, the rate of resistance to colistin, sitafloxacin, and tigecycline was relatively low (0%, 41.1%, and 65.1%, respectively). The MIC50 and MIC90 of ciprofloxacin, levofloxacin, and sitafloxacin were 128 mg/L and >128 mg/L; 16 mg/L and 64 mg/L; 2 mg/L and 8 mg/L, respectively. Compared with ciprofloxacin and levofloxacin, sitafloxacin had a significantly lower MIC (p < 0.001), and the rate of resistance to sitafloxacin was significantly lower than that to ciprofloxacin (97.9% vs. 41.1%, p < 0.001), levofloxacin (97.3% vs. 41.1%, p < 0.001), and tigecycline (p < 0.001).
Sitafloxacin has acceptable in vitro activity against CRAB, even against isolates resistant to other fluoroquinolones. Sitafloxacin may be considered an alternative drug of choice in treating CRAB related infections.
碳青霉烯类耐药鲍曼不动杆菌（CRAB）的出现给全球临床医生带来了巨大挑战。西他沙星已被证明对其他氟喹诺酮类耐药的病原体具有体外活性。然而，比较西他沙星与其他抗菌药物抗 CRAB 活性的数据有限。
通过 16S-23S 核糖体 RNA 基因间隔区测序确定基因种。采用琼脂稀释法测定最低抑菌浓度（MIC）。西他沙星 MIC≤2mg/L 的分离株被暂时认为对西他沙星敏感。替加环素敏感性的 MIC 折点为 2mg/L。
从 2009 年 1 月至 2011 年 12 月共收集了 167 株 CRAB 复合血液分离株（146 株鲍曼不动杆菌、7 株醋酸钙不动杆菌和 14 株鲍曼不动杆菌 nosocomialis）。约 90%的鲍曼不动杆菌分离株对阿米卡星、头孢吡肟、头孢他啶、哌拉西林/他唑巴坦、氨苄西林/舒巴坦、环丙沙星和左氧氟沙星耐药。相比之下，对黏菌素、西他沙星和替加环素的耐药率相对较低（分别为 0%、41.1%和 65.1%）。环丙沙星、左氧氟沙星和西他沙星的 MIC50 和 MIC90 分别为 128mg/L 和>128mg/L；16mg/L 和 64mg/L；2mg/L 和 8mg/L。与环丙沙星和左氧氟沙星相比，西他沙星的 MIC 明显更低（p<0.001），且对西他沙星的耐药率明显低于环丙沙星（97.9%比 41.1%，p<0.001）、左氧氟沙星（97.3%比 41.1%，p<0.001）和替加环素（p<0.001）。
西他沙星对 CRAB 具有可接受的体外活性，甚至对其他氟喹诺酮类耐药的分离株也有活性。西他沙星可作为治疗 CRAB 相关感染的替代药物。
