Shungu D L, Weinberg E, Gadebusch H H
Antimicrob Agents Chemother. 1983 Feb;23(2):256-60. doi: 10.1128/AAC.23.2.256.
Norfloxacin is a new orally absorbed quinoline derivative structurally related to nalidixic acid but showing an expanded antibacterial spectrum which includes Enterobacteriaceae, Pseudomonas aeruginosa, Streptococcus faecalis, and staphylococci, among other susceptible bacterial species. The application of the regression line and error rate-bounded methods of analysis to the minimal inhibitory concentration and zone size data collected on 413 clinical isolates favored the selection of a 10-micrograms disk content and the adoption of the following interpretive zone size breakpoints for antimicrobial susceptibility testing with norfloxacin: greater than or equal to 17 mm for susceptible, 13 to 16 mm for intermediate, and less than or equal to 12 mm for resistant categories. It is proposed that isolates with minimal inhibitory concentrations of less than or equal to 16 and greater than or equal to 32 micrograms/ml be considered susceptible and resistant to norfloxacin, respectively. Differences in the antibiotic disk contents and in vitro antibacterial spectra and pharmacokinetic properties, together with the much lower rates of cross-resistance reported between norfloxacin and related drugs, strongly argue against the use of the "class disk" concept in this instance and suggest that the 10-micrograms norfloxacin susceptibility disk should be tested separately.
诺氟沙星是一种新的口服吸收喹啉衍生物，在结构上与萘啶酸相关，但抗菌谱有所扩大，包括肠杆菌科、铜绿假单胞菌、粪肠球菌和葡萄球菌等其他敏感细菌种类。将回归线和误差率限定分析方法应用于收集的413株临床分离株的最低抑菌浓度和抑菌圈大小数据，有利于选择含10微克药物的药敏纸片，并采用以下诺氟沙星抗菌药敏试验的抑菌圈大小判断标准：敏感为大于或等于17毫米，中介为13至16毫米，耐药为小于或等于12毫米。建议最低抑菌浓度小于或等于16微克/毫升和大于或等于32微克/毫升的分离株分别视为对诺氟沙星敏感和耐药。抗生素药敏纸片含量、体外抗菌谱和药代动力学特性的差异，以及诺氟沙星与相关药物之间报道的交叉耐药率低得多，强烈反对在这种情况下使用“类药敏纸片”概念，并建议单独检测含10微克的诺氟沙星药敏纸片。
