Facinelli B, Magi G, Prenna M, Ripa S, Varaldo P E
Institute of Microbiology, University of Ancona Medical School, Monte d'Ago, Italy.
Eur J Clin Microbiol Infect Dis. 1997 Nov;16(11):827-33. doi: 10.1007/BF01700413.
Two new fluoroquinolones (trovafloxacin and sparfloxacin) with enhanced activity against gram-positive pathogens and two earlier compounds (ciprofloxacin and ofloxacin) were tested for their in vitro inhibitory and bactericidal activity against 80 strains of Listeria monocytogenes. All strains were uniformly highly susceptible to trovafloxacin, the MIC90 being 0.25 mg/l. Resistance to sparfloxacin was not detected, however the MIC90 of sparfloxacin was eight times that of trovafloxacin. A few strains were resistant to ciprofloxacin and ofloxacin (MIC90 4 mg/l for both drugs). MBCs usually exceeded MICs by 2 to 4 times. The MBC90 of trovafloxacin (1 mg/l) was lower than that of the other three drugs (8 mg/l). After checking their ability to enter and grow within human enterocyte-like Caco-2 cells, four strains were used to study the intracellular activity and eradicating power of the four quinolones. Trovafloxacin was more active than sparfloxacin and the earlier fluoroquinolones in terms of both intracellular killing and inhibition of a cytopathogenic effect. The uniform high-level activity of trovafloxacin against Listeria monocytogenes isolates in conventional in vitro assays and its extracellular and intracellular killing of invasive strains suggest that this and maybe other new fluoroquinolones should be further investigated as possible anti-listerial agents.
对两种对革兰氏阳性病原体活性增强的新型氟喹诺酮类药物（曲伐沙星和司帕沙星）以及两种较早的化合物（环丙沙星和氧氟沙星）进行了体外试验，检测它们对80株单核细胞增生李斯特菌的抑制和杀菌活性。所有菌株对曲伐沙星均高度敏感，MIC90为0.25mg/L。未检测到对司帕沙星的耐药性，但其MIC90是曲伐沙星的8倍。少数菌株对环丙沙星和氧氟沙星耐药（两种药物的MIC90均为4mg/L）。MBC通常比MIC高2至4倍。曲伐沙星的MBC90（1mg/L）低于其他三种药物（8mg/L）。在检测了它们进入人肠上皮样Caco-2细胞并在其中生长的能力后，使用四株菌株研究了这四种喹诺酮类药物的细胞内活性和根除能力。在细胞内杀灭和抑制细胞病变效应方面，曲伐沙星比司帕沙星和早期氟喹诺酮类药物更具活性。曲伐沙星在传统体外试验中对单核细胞增生李斯特菌分离株具有一致的高水平活性，以及对侵袭性菌株的细胞外和细胞内杀灭作用，表明该药物以及可能的其他新型氟喹诺酮类药物应作为可能的抗李斯特菌药物进行进一步研究。
