a molecule-dependent target specifi city: mutations in parC are generally selected by pefl oxacin, ciprofl oxacin, and levofl oxacin, and those in gyrA are selected by sparfl oxacin, gatifl oxacin, moxifl oxacin, gemifl oxacin, and garenoxacin (5). In second-step mutants, mutations are present in both parC and gyrA and confer resistance to the antistreptococcal FQs levofl oxacin, moxifl oxacin,...

Twelve clinical isolates of Ureaplasma spp. and one isolate of Mycoplasma hominis were examined for resistance to fluoroquinolones. Previously described mutations at positions 83 and 95 in GyrA (Escherichia coli numbering) and positions 80 and 87 in ParC were found. Unusual alterations were described at positions ParC 123 and 134.

1Centre Tecnològic de Telecomunicacions de Catalunya (CTTC), Avinguda Del Canal Oĺımpic S/N, Parc Mediterrani de la Tecnologia, 08860 Castelldefels, Barcelona, Spain 2Department of Signal Theory and Communications, Escola Politècnica Superior de Castelldefels (EPSC), Universitat Politècnica de Catalunya (UPC), Avinguda Del Canal Oĺımpic S/N, Parc Mediterrani de la Tecnologia, 08860 Castelldefel...

The gyrA and parC genes of 31 clinical isolates of Enterococcus faecalis, including fluoroquinolone-resistant isolates, were partially sequenced and analyzed for target alterations. Topoisomerase IV may be a primary target in E. faecalis, but high-level fluoroquinolone resistance was associated with simultaneous alterations in both GyrA and ParC.

* Faical Akaichi (Corresponding author) CREDA-UPC-IRTA. Parc Mediterrani de la Tecnologia; Av. Canal Olimpic, 15; 08860-Castelldefels. Barcelona Spain. Phone: +34-935521208. Fax 34935521121. Email: [email protected]. José M. Gil. CREDA-UPC-IRTA. Parc Mediterrani de la Tecnologia; Av. Canal Olimpic, 15; 08860-Castelldefels. Barcelona Spain. Phone: +34-935521210. Fax +34-935521121. Email: ch...

AIM To analyse mutations in the gyrA and parC genes leading to possible increase in ciprofloxacin resistance (high MIC values for ciprofloxacin) in clinical isolates of Neisseria gonorrhoeae in Delhi, India. METHOD MIC of ciprofloxacin for 63 clinical isolates of N gonorrhoeae were examined by the Etest method. Subsequently, gyrA and parC genes of these isolates were amplified and sequenced f...

Introduction Pseudomonas aeruginosa has many mechanisms of resistance to fluoroquinolones. The main mechanism is to change the effect of two enzymes that open the DNA helix - the enzyme DNA gyrase (gyrA) and the topoisomerase IV (parC). In addition, mutations that render the MexAB-oprM pump (mexR) dysfunctional, leading to its overexpression, also enhance resistance to fluoroquinolones. In this...