Jones R N, Johnson D M, Erwin M E, Beach M L, Biedenbach D J, Pfaller M A
Medical Microbiology Division, University of Iowa College of Medicine, Iowa City 52242, USA.
Diagn Microbiol Infect Dis. 1999 Jun;34(2):91-8. doi: 10.1016/s0732-8893(98)00085-6.
Gatifloxacin (formerly AM-1155 or CG 5501) is a new 8-methoxy fluoroquinolone with enhanced activity against Gram-positive cocci, especially Streptococcus pneumoniae and other streptococci. Recent clinical strains (599 isolates) were tested against gatifloxacin, three comparison fluoroquinolones, and penicillin by the reference broth microdilution, Etest (AB BIODISK, Solna, Sweden) and standardized disk diffusion methods (5 micrograms gatifloxacin disk). Gatifloxacin (MIC90, 0.5 microgram/ml) activity was generally comparable to that of trovafloxacin (MIC90, 0.25 microgram/ml), or sparfloxacin (MIC90, 0.5 microgram/ ml) and markedly superior to ofloxacin (MIC90, 2-4 micrograms/ml) against the streptococci. Rates of penicillin non-susceptibility were 41.9, 38.0, and 16.2% for S. pneumoniae (301 strains), viridans group streptococci (150 strains), and beta-haemolytic streptococci (148 strains). Etest results correlated well (95.7-100.0% +/- one log2 dilution) with the reference MIC results, but Etest tended to have elevated gatifloxacin MIC results compared to the broth microdilution method for the highly resistant isolates (MICs, > 2 micrograms/ml). Gatifloxacin disk zone diameters correlate well to reference MICs for all streptococci and proposed interpretive criteria (susceptible at < or = 1 microgram/ml or > or = 18 mm, and resistant at > or = 4 micrograms/ml or < or = 14 mm) did not produce discords between method results (absolute agreement). A nine laboratory quality control (QC) study conforming to the National Committee for Clinical Laboratory Standards (NCCLS) Guideline M23-T3 studied S. pneumoniae ATCC 49619 and gatifloxacin. Proposed ranges for QC of NCCLS tests were 0.12-0.5 microgram/ml for the broth microdilution test and 24-31 mm for the disk diffusion method. These reported results indicate that gatifloxacin was a potent fluoroquinolone with extensive activity against streptococcal isolates. In vitro test methods to measure this activity appear accurate and comparable; and QC guidelines have been established for routine clinical laboratory use pending approval by the NCCLS and the Food and Drug Administration (FDA).
加替沙星（曾用名AM - 1155或CG 5501）是一种新型8 - 甲氧基氟喹诺酮类药物，对革兰氏阳性球菌，尤其是肺炎链球菌和其他链球菌具有增强的活性。采用参考肉汤微量稀释法、Etest法（AB BIODISK公司，瑞典索尔纳）和标准化纸片扩散法（5微克加替沙星纸片），对近期的临床菌株（599株分离菌）进行了加替沙星、三种对照氟喹诺酮类药物和青霉素的检测。加替沙星（MIC90，0.5微克/毫升）对链球菌的活性总体上与曲伐沙星（MIC90，0.25微克/毫升）或司帕沙星（MIC90，0.5微克/毫升）相当，且明显优于氧氟沙星（MIC90，2 - 4微克/毫升）。肺炎链球菌（301株）、草绿色链球菌（150株）和β - 溶血性链球菌（148株）对青霉素不敏感的比例分别为41.9%、38.0%和16.2%。Etest结果与参考MIC结果相关性良好（95.7 - 100.0%，±1个log2稀释度），但对于高度耐药菌株（MICs＞2微克/毫升），与肉汤微量稀释法相比，Etest法测得的加替沙星MIC结果往往偏高。加替沙星纸片抑菌圈直径与所有链球菌的参考MICs相关性良好，所提出的解释标准（MIC≤1微克/毫升或抑菌圈直径≥18毫米为敏感，MIC≥4微克/毫升或抑菌圈直径≤14毫米为耐药）在两种方法结果之间未产生不一致（完全一致）。一项符合美国国家临床实验室标准委员会（NCCLS）M23 - T3指南的九实验室质量控制（QC）研究，对肺炎链球菌ATCC 49619和加替沙星进行了研究。NCCLS试验的QC建议范围，肉汤微量稀释试验为0.12 - 0.5微克/毫升，纸片扩散法为24 - 31毫米。这些报告结果表明，加替沙星是一种对链球菌分离株具有广泛活性的强效氟喹诺酮类药物。用于测量这种活性的体外试验方法似乎准确且具有可比性；并且在NCCLS和美国食品药品监督管理局（FDA）批准之前，已制定了用于常规临床实验室的QC指南。
