Escalating resistance to azithromycin and moxifloxacin is being reported for Mycoplasma genitalium in the Asia-Pacific region. Analyzing 140 infections, we found pretreatment fluoroquinolone-resistance mutations in parC (13.6%) and gyrA (5%). ParC S83 changes were associated with moxifloxacin failure. Combined macrolide/fluoroquinolone-resistance mutations were in 8.6% of specimens, for which r...

BACKGROUND Staphylococcus epidermidis is one of the prominent pathogens in ocular infection. The prevalence of mutations in the quinolone resistance determining region (QRDR) area in S epidermidis isolated from the ocular surface and its association with fluoroquinolone resistance has not been fully elucidated. METHODS Mutations in the QRDR of gyrA, gyrB, parC, and parE genes of 138 isolates ...

Fluoroquinolones remain the most commonly used antimicrobials for the prevention and management of bacterial endophthalmitis. Coagulase-negative staphylococci are the most frequently recovered pathogens. Increasing resistance among this group has paralleled the presence of methicillin resistance. From 2005 to 2010, we recovered 38 methicillin-susceptible Staphylococcus epidermidis (MSSE) isolat...

Sixty extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolated from rivers and lakes in Switzerland were screened for individual strains additionally exhibiting a reduced quinolone susceptibility phenotype. Totally, 42 such isolates were found and further characterized for their molecular (fluoro)quinolone resistance mechanisms. PCR and sequence analysis were performed to identi...

The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolate...

A total of 83 Vibrio isolates from farmed marine shrimps (Penaeus monodon) were tested for the presence of class 1, 2 and 3 integrons, SXT constin and tetracycline resistance-encoding genes. Mutations in the quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes were determined in fluoroquinolone-resistant Vibrio strains (n=17). Five isolates were found to carry class 1 int...

Resistance to fluoroquinolone (FQ) antibiotics in Streptococcus pneumoniae has been attributed primarily to specific mutations in the genes for DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE). Resistance to some FQs can result from a single mutation in one or more of the genes encoding these essential enzymes. A group of 160 clinical isolates of pneumococci was examined in this ...

BACKGROUND Previous work showed that piperazinyl-cross-linked ciprofloxacin dimer exhibits good bacteriostatic activity with Streptococcus pneumoniae and Staphylococcus aureus; lethal activity was not measured. Subsequently, the dimer failed to kill Mycobacterium smegmatis but blocked growth. Whether the compound is lethal with non-mycobacterial species is not known. METHODS Bacteriostatic an...

OBJECTIVES To compare the in vitro activity of moxifloxacin and ciprofloxacin against 226 nosocomial isolates of Acinetobacter baumannii from 44 hospitals in the UK. METHODS MICs of ciprofloxacin and moxifloxacin were determined by Etest. PCR analysis was used to detect chromosomal mutations in the gyrA and parC genes. Isolates resistant to ciprofloxacin and susceptible to moxifloxacin were e...

Selection of resistant strains in Streptococcus pneumoniae was studied in vitro with nemonoxacin, a novel nonfluorinated quinolone (NFQ), in comparison with quinolone benchmarks, ciprofloxacin, garenoxacin, and gatifloxacin. In stepwise resistance selection studies, a 256-fold loss of potency was observed after three to four steps of exposure to ciprofloxacin or garenoxacin. In contrast, the lo...