OBJECTIVES To determine the frequency of selecting mutants resistant to ozenoxacin, a des-fluoro-(6)-quinolone active against pathogens involved in skin and skin structure infections, compared with levofloxacin and ciprofloxacin in quinolone-susceptible and -resistant Gram-positive cocci. METHODS Forty-nine quinolone-susceptible and -resistant Gram-positive cocci strains with different profil...

BACKGROUND Emergence of quinolone-resistant Escherichia coli (QREC) is an increasing clinical challenge mostly originating in fecal microbiota. The dynamics of the emergence of QREC in feces from individuals exposed to ciprofloxacin is unknown. METHODS A total of 48 healthy volunteers received oral ciprofloxacin for 14 days. Fecal specimens were collected on days 0, 8, 14, and 42. Subpopulati...

Sparfloxacin (SPFX) and levofloxacin (LVFX) with ultraviolet-A (UVA) irradiation have been reported to induce skin inflammation due to phototoxicity in Balb/c mice. We examined the production of arachidonic acid metabolites induced by quinolone phototoxicity in Balb/c 3T3 mouse fibroblast cells in vitro. The cells were simultaneously treated with SPFX or LVFX at 1, 10, or 100 microM and UVA irr...

Quinolone resistance is usually due to mutations in the genes encoding bacterial topoisomerases. However, different reports have shown that neither clinical quinolone resistant isolates nor in vitro obtained Stenotrophomonas maltophilia mutants present mutations in such genes. The mechanisms so far described consist on efflux pumps' overexpression. Our objective is to get information on novel mec...

Nuclear medicine imaging has been used to localize infection sites, and efforts have been continued to develop modified infection specific radiopharmaceuticals. In this study gemifloxacin as a broad-spectrum quinolone has been labeled with [99mTc (CO)3 (H2O)3]+ core in order to evaluate its feasibility as an infection imaging agent for in-vivo use. The stability of radioconjugate was checked in...

OBJECTIVES To investigate the potential relationship between quinolone resistance and biofilm production in a collection of Salmonella enterica clinical isolates and in S. enterica serovar Typhimurium serial mutants with increasing resistance to ciprofloxacin. METHODS Nalidixic acid susceptibility and biofilm formation were assessed in a collection of 122 S. enterica clinical isolates. An in ...

DC-159a yielded MICs of or=4 microg/ml). Although the MICs for DC-159a against quinolone-susceptible pneumococci were a few dilutions higher than those of gemifloxacin, the MICs of these two compounds against 28 quinolone-resistant pneumococci were identical. ...

INTRODUCTION Plasmid-mediated quinolone resistance, which complicates treatment, has been increasingly identified in Escherichia coli isolates worldwide. The purpose of this study was to identify the plasmid-mediated qnrA and qnrB genes among the quinolone-resistant Escherichia coli isolated from urinary tract infections in Iran. METHODOLOGY A total of 140 Escherichia coli isolates were colle...

The growing frequency of antibiotic resistances is now a universal problem. Increasing resistance to new generations of β-lactam and quinolone antibiotics in multidrug-resistant Enterobacteriaceae isolates is considered an emergency health issue worldwide. The aim of this study was to evaluate plasmid-mediated quinolone resistance genes in ESBL-producing Escherichia coli isolated from urinary t...

Quinolone resistance normally arises by mutations in the chromosomal genes for type II topoisomerases and by changes in the expression of proteins that control the accumulation of quinolones inside bacteria. A novel mechanism of plasmid-mediated quinolone resistance was recently reported that involves DNA gyrase protection by a pentapeptide repeat family member called Qnr. This family includes ...