Higa Futoshi, Akamine Morikazu, Haranaga Shusaku, Tohyama Masato, Shinzato Takashi, Tateyama Masao, Koide Michio, Saito Atsushi, Fujita Jiro
First Department of Internal Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan.
J Antimicrob Chemother. 2005 Dec;56(6):1053-7. doi: 10.1093/jac/dki391. Epub 2005 Oct 31.
The activities of pazufloxacin and tosufloxacin against Legionella spp. were evaluated in vitro and compared with those of other quinolones, macrolides and azithromycin.
The conventional MICs were determined by the microbroth dilution method. Intracellular activities of drugs were evaluated by a cfu count. The minimal extracellular concentration inhibiting intracellular growth of bacteria (MIEC) was determined by a colorimetric cytopathic assay.
MICs of pazuloxacin and tosufloxacin at which 90% (MIC90) of isolates are inhibited in 76 different Legionella spp. strains (38 ATCC strains and 38 clinical isolates) were 0.032 and 0.016 mg/L, whereas the MIC90s of levofloxacin, ciprofloxacin, garenoxacin, erythromycin, clarithromycin and azithromycin were 0.032, 0.032, 0.032, 2.0, 0.125 and 2.0 mg/L, respectively. Pazufloxacin and tosufloxacin at 4x MIC inhibited intracellular growth of Legionella pneumophila SG1 (80-045 strain), as did other quinolones, clarithromycin and azithromycin, whereas erythromycin at 4x MIC did not. MIECs of pazufloxacin, tosufloxacin, levofloxacin, ciprofloxacin and garenoxacin for the strain were 0.063, 0.004, 0.016, 0.032 and 0.008 mg/L respectively, which were superior to those of macrolides and azithromycin. Pazufloxacin showed potent activity against three additional clinical isolates of L. pneumophila SG1, one clinical isolate each of L. pneumophila SG3 and SG5, as well as Legionella micdadei, Legionella dumoffii and Legionella longbeachae SG1.
Pazufloxacin and tosufloxacin, as well as other quinolones, were more potent than macrolides and an azalide. Present data warrant further study on the efficacy of these drugs in the treatment of Legionella infections.
体外评估帕珠沙星和托氟沙星对军团菌属的活性，并与其他喹诺酮类、大环内酯类及阿奇霉素进行比较。
采用微量肉汤稀释法测定常规最低抑菌浓度（MIC）。通过菌落形成单位（cfu）计数评估药物的细胞内活性。采用比色细胞病变试验测定抑制细菌细胞内生长的最低细胞外浓度（MIEC）。
在76株不同的军团菌属菌株（38株美国典型培养物保藏中心菌株和38株临床分离株）中，帕珠沙星和托氟沙星抑制90%分离株（MIC90）的MIC分别为0.032和0.016mg/L，而左氧氟沙星、环丙沙星、加替沙星、红霉素、克拉霉素和阿奇霉素的MIC90分别为0.032、0.032、0.032、2.0、0.125和2.0mg/L。4倍MIC的帕珠沙星和托氟沙星可抑制嗜肺军团菌SG1（80 - 045株）的细胞内生长，其他喹诺酮类、克拉霉素和阿奇霉素也有此作用，而4倍MIC的红霉素则无此作用。该菌株的帕珠沙星、托氟沙星、左氧氟沙星、环丙沙星和加替沙星的MIEC分别为0.063、0.004、0.016、0.032和0.008mg/L，优于大环内酯类和阿奇霉素。帕珠沙星对另外3株嗜肺军团菌SG1临床分离株、1株嗜肺军团菌SG3临床分离株、1株嗜肺军团菌SG5临床分离株以及米克戴德军团菌、杜莫夫军团菌和长滩军团菌SG1均显示出强效活性。
帕珠沙星和托氟沙星以及其他喹诺酮类药物比大环内酯类和氮杂内酯类药物活性更强。目前的数据表明有必要进一步研究这些药物治疗军团菌感染的疗效。
