Toronto Public Health Laboratory, Ontario Agency for Health Protection and Promotion, Toronto, Ontario, Canada.
Antimicrob Agents Chemother. 2011 Aug;55(8):3703-8. doi: 10.1128/AAC.00237-11. Epub 2011 May 31.
Ciprofloxacin, the first fluoroquinolone to be used to treat lower respiratory tract infections (LRTI), demonstrates poor potency against Streptococcus pneumoniae, and its use has been associated with the emergence of resistance. During the last decade, fluoroquinolones with enhanced in vitro activity against S. pneumoniae have replaced ciprofloxacin for the treatment of LRTI. Here, we analyzed the impact of more active fluoroquinolone usage on pneumococci by examining the fluoroquinolone usage, prevalence of fluoroquinolone resistance, and mutations in the genes that encode the major target sites for the fluoroquinolones (gyrA and parC) in pneumococcal isolates collected in Canada-wide surveillance. A total of 26,081 isolates were collected between 1998 and 2009. During this time period, total per capita outpatient use of fluoroquinolones increased from 64 to 96 prescriptions per 1,000 persons per year. The proportion of prescriptions for respiratory tract infection that were for fluoroquinolones increased from 5.9% to 10.7%, but the distribution changed: the proportion of prescriptions for ciprofloxacin decreased from 5.3% to 0.5%, and those for levofloxacin or moxifloxacin increased from 1.5% in 1999 to 5.9% in 2009. The prevalence of ciprofloxacin resistance (MIC ≥ 4 μg/ml), levofloxacin resistance, and moxifloxacin resistance remained unchanged at <2%. Multivariable analyses showed that prevalence of mutations known to be associated with reduced susceptibility to fluoroquinolones did not change during the surveillance period. If fluoroquinolone therapy is required, the preferential use of fluoroquinolones with enhanced pneumococcal activity to treat pneumococcal infections may slow the emergence of resistance in S. pneumoniae.
环丙沙星是第一个用于治疗下呼吸道感染（LRTI）的氟喹诺酮类药物，对肺炎链球菌的作用较弱，其使用与耐药性的出现有关。在过去的十年中，具有增强对肺炎链球菌体外活性的氟喹诺酮类药物已取代环丙沙星用于治疗 LRTI。在这里，我们通过检查氟喹诺酮类药物的使用情况、氟喹诺酮类药物耐药率以及编码氟喹诺酮类药物主要靶位（gyrA 和 parC）的基因中的突变，分析了更活跃的氟喹诺酮类药物使用对肺炎链球菌的影响，这些肺炎链球菌分离株是在加拿大全国范围内的监测中收集的。1998 年至 2009 年间共收集了 26081 株分离株。在此期间，氟喹诺酮类药物的人均门诊用量从每人每年 64 增至 96 剂。用于呼吸道感染的处方中氟喹诺酮类药物的比例从 5.9%增至 10.7%，但分布发生了变化：环丙沙星的处方比例从 5.3%降至 0.5%，而左氧氟沙星或莫西沙星的处方比例从 1999 年的 1.5%增至 2009 年的 5.9%。环丙沙星耐药（MIC≥4μg/ml）、左氧氟沙星耐药和莫西沙星耐药的流行率仍保持在<2%不变。多变量分析显示，与氟喹诺酮类药物敏感性降低相关的突变的流行率在监测期间没有变化。如果需要氟喹诺酮类药物治疗，首选对肺炎链球菌活性增强的氟喹诺酮类药物治疗肺炎链球菌感染可能会减缓肺炎链球菌耐药性的出现。
