In gram-negative bacteria, gyrase and topoisomerase IV are primary and secondary targets, respectively, of the fluoroquinolones. In addition to the mutations in the genes encoding the target enzymes (1, 4), quinolone resistance may also be associated with increased efflux of the drugs (2, 5). Possible mechanisms of quinolone resistance were investigated in clinical isolates of Shigella dysenter...

OBJECTIVES To gain insight into the functionality of qnr-like genes of several bacterial species of Vibrionaceae that may encode quinolone resistance determinants. METHODS A PCR-based strategy was used to obtain qnr-like genes of reference strains of Vibrio vulnificus CIP103196, Vibrio parahaemolyticus CIP71.2 and Photobacterium profundum CIP106289 that were sequenced, cloned and expressed in...

BACKGROUND Given that the quinolones is one of the antibacterial classes most frequently used to treat patients with bacterial infections in the United States, any change in prescribing patterns of quinolones will impact Medicaid medical expenditures. OBJECTIVES This study was undertaken to examine trends in utilization, reimbursement, and prices of quinolone antibacterials for the US Medicai...

Quinolones are one of the most commonly prescribed classes of antibacterials in the world and are used to treat a variety of bacterial infections in humans. Because of the wide use (and overuse) of these drugs, the number of quinolone-resistant bacterial strains has been growing steadily since the 1990s. As is the case with other antibacterial agents, the rise in quinolone resistance threatens ...

The quinolones exert their anti-bacterial activity by binding to DNA gyrase A (GyrA), an essential enzyme in maintenance of DNA topology within bacterial cell. The mutations conferring resistance to quinolones arise within the quinolone-resistance-determining region (QRDR) of GyrA. Therefore, quinolones interaction with wild and mutated GyrA can provide the molecular explanation for resistance....

BACKGROUND Quinolone is recommended as an antimicrobial prophylaxis to prevent infectious complication after transrectal ultrasound-guided biopsy, but the increased appearance of quinolone-resistant organism has raised concerns about the efficacy of quinolone. The current study was performed to evaluate various clinical factors including antimicrobial regimens associated with infectious complic...

Eighty-nine clinical isolates of Staphylococcus aureus that were resistant to both ciprofloxacin (MIC, greater than or equal to 3.13 micrograms/ml) and methicillin (MIC, greater than or equal to 12.5 micrograms/ml) were divided into two groups with respect to their susceptibilities to AT-4140. Most isolates that were moderately resistant to ciprofloxacin (MICs, 3.13 to 12.5 micrograms/ml) or of...

WCK 771, the arginine salt of S-(-)-nadifloxacin, was evaluated in animal models of staphylococcal infection and in vitro. For 302 methicillin-susceptible strains the MIC at which 50% of isolates are inhibited (MIC50) and the MIC90 of WCK 771 were 0.03 and 0.03 microg/ml, respectively, and for 198 methicillin-resistant strains the MIC50 and the MIC90 were 0.5 and 1.0 microg/ml, respectively. Al...