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Updated: Oct 10, 2026

Quantification of Violacein in Chromobacterium violaceum and Its Inhibition by Bioactive Compounds
Published on: August 8, 2025
[Activity of new quinolones against clinical isolates of Corynebacterium species]
G Yagüe Guirao1, M C Martínez-Toldos, B Mora Peris
1Departamento de Genética y Microbiología, Facultad de Medicina, Universidad de Murcia.
Abstract:
The activity of six quinolones (ciprofloxacin, levofloxacin, trovafloxacin, moxifloxacin, clinafloxacin and grepafloxacin) against 86 clinical isolates of Corynebacterium spp. obtained from different clinical sources was studied. Of these, 30 isolates were identified as C. jeikeium, 30 as C. urealyticum and 26 as C. amycolatum. C. amycolatum was the most resistant species, with 85.5% of the strains analyzed resistant to all the quinolones studied. Clinafloxacin showed the best activity against these species with a concentration range between <0.01 and 8 mg/l, and MIC50 and MIC90 64 and 32 times lower, respectively, than the MICs of ciprofloxacin. The majority of the isolates (90%) of C. jeikeium and C. urealyticum were susceptible to all the quinolones studied. Only 9.9% of the C. jeikeium strains and 13.2% of the C. urealyticum strains were resistant to ciprofloxacin, which showed the lowest activity of the antimicrobial agents evaluated. Clinafloxacin, grepafloxacin and moxifloxacin were the most active quinolones against these two multiresistant species.
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