INTRODUCTION Previous work has shown that besifloxacin, an 8-chloro-fluoroquinolone, has more potent activity against gram-positive pathogens than moxifloxacin and gatifloxacin, which carry an 8-methoxy group. This study was conducted to determine the contribution of the R7 and R8 substituent to fluoroquinolone antibacterial activity. MATERIALS AND METHODS Besifloxacin, moxifloxacin, gatiflox...

CONTEXT Thiomers could prove to be suitable mucoadhesives for fabrication of ocular inserts. OBJECTIVE The study intends to explore the application of thiolated sodium alginate (TSA) to the preparation of bilayered ocular inserts of gatifloxacin. METHODS Cysteine moieties were grafted onto sodium alginate (SA) and the resultant thiomer was characterized for relevant physicochemical properti...

OBJECTIVES Mutations in the gyrase genes cause fluoroquinolone resistance in Mycobacterium tuberculosis. However, the predictive value of these markers for clinical outcomes in patients with MDR-TB is unknown to date. The objective of this study was to determine molecular markers and breakpoints predicting second-line treatment outcomes in M. tuberculosis patients treated with fourth-generation...

OBJECTIVES Decreasing susceptibility of Neisseria gonorrhoeae to fluoroquinolones has been reported in several countries. Knowledge of local N gonorrhoeae susceptibilities to various antimicrobials is important for establishing a rational treatment strategy in each region. METHODS Isolates of N gonorrhoeae from male urethritis patients attending four urological clinics in Hyogo and Osaka pref...

Antibacterial activities of gatifloxacin (AM1155), a new C-8-methoxy fluoroquinolone, and two structurally related compounds, AM1121 and ciprofloxacin, were studied with an isogenic set of ten quinolone-resistant, gyrA (gyrase) mutants of Escherichia coli. To compare the effect of each mutation on resistance, the mutant responses were normalized to those of wild-type cells. Alleles exhibiting t...

OBJECTIVES To investigate the impact of low levels of fluoroquinolone resistance on the emergence of resistant mutants, we examined the mutant selection window (MSW) hypothesis in experimental pneumonia in rabbits infected with pneumococci with various susceptibility levels to fluoroquinolones and treated with gatifloxacin using a human-like regimen (equivalent to 400 mg once daily). The MSW co...

Novel analogues of N-piperazinyl fluoroquinolones were prepared and evaluated against a panel of Gram-positive and Gram-negative bacteria, to study the effect of introducing bulky anthracene and phenanthrene moieties on the antibacterial effects of norfloxacin, ciprofloxacin and gatifloxacin. Although most of the novel synthesized compounds had lower antibacterial effects, some derivatives show...

A simple and rapid microextraction procedure based on the application of magnetic nanoparticles and hydrophobic 1-Hexylpyridinium hexafluorophosphate [Hpy][PF6] ionic liquid (IL) was applied to trace determination of gatifloxacin. A mixture of [Hpy][PF6] and magnetic nanoparticles was injected into the sample solution containing the analyse of interest and a cloudy solution was forme...

A simple and rapid microextraction procedure based on the application of magnetic nanoparticles and hydrophobic 1-Hexylpyridinium hexafluorophosphate [Hpy][PF6] ionic liquid (IL) was applied to trace determination of gatifloxacin. A mixture of [Hpy][PF6] and magnetic nanoparticles was injected into the sample solution containing the analyse of interest and a cloudy solution was forme...