balofloxacin and Eye-Infections--Bacterial

To evaluate the effectiveness of balofloxacin for treatment of experimental Staphylococcus aureus keratitis.. In vitro testing compared the cellular toxicity of and bacterial susceptibility to balofloxacin and levofloxacin in human corneal epithelial cells (HCECs). For in vivo testing, experimental bacterial keratitis was induced and treated with balofloxacin eye drops (0.5%) and levofloxacin eye drops (0.5%).. In vitro toxicity examinations showed that balofloxacin, as well as levofloxacin, had low cytotoxicity in HCECs. Balofloxacin eye drops (0.5%) also showed a similar relative cytotoxicity to levofloxacin eye drops (0.5%). In bacterial susceptibility examinations, both balofloxacin and levofloxacin significantly reduced S. aureus compared with the untreated control (P<0.001 for both balofloxacin and levofloxacin). Balofloxacin was more effective than levofloxacin in the treatment of S. aureus bacterial keratitis (P<0.05). In experimental bacterial keratitis treatment testing, balofloxacin was also more effective than levofloxacin with respect to the parameters of physiological score, histological observation, and bacterial quantitation (P<0.05).. Balofloxacin was safe in the treatment of S. aureus bacterial keratitis, and more effective than levofloxacin. Therefore, balofloxacin was shown to have potential clinical value in ophthalmic local application.

Topics: Animals; Anti-Bacterial Agents; Cell Line; Disease Models, Animal; Eye Infections, Bacterial; Fluoroquinolones; Humans; Keratitis; Levofloxacin; Microbial Sensitivity Tests; Ophthalmic Solutions; Rabbits; Staphylococcal Infections; Staphylococcus aureus

Staphylococcus epidermidis is considered a commensal bacterium; however, it is frequently isolated from ocular infections showing a multidrug resistance. Ciprofloxacin-resistant strains have been isolated from ocular infections; however, resistance to quinolone, such as gatifloxacin and moxifloxacin, is not often studied, consequently the resistance mechanism is unknown. Our aim was to address the quinolone resistance and to explore the resistance mechanism in S. epidermidis strains isolated from ocular infections.. S. epidermidis strains were isolated from patients with conjunctivitis (n = 23), endophthalmitis (n = 14) and corneal ulcers (n = 7). Minimum inhibition concentrations were determined by broth and agar dilution methods for moxifloxacin, gatifloxacin, balofloxacin, rufloxacin and pazufloxacin. Mutations were identified by sequencing the gyrA and parC genes, and their expression was determined by reverse transcriptase polymerase chain reaction.. We found that 13.6% (6/44) of the strains were quinolone resistant. In endophthalmitis, 21.4% were gatifloxacin, moxifloxacin and balofloxacin resistant. In corneal ulcers, 14.2, 14.2 and 28.5% were gatifloxacin, moxifloxacin and balofloxacin resistant, respectively, and in conjunctivitis only 4.3% were gatifloxacin resistant. The 6 strains with quinolone resistance showed mutations at Ser84Phe for the gyrA gene, and Ser80Phe for the parC gene. Gatifloxacin did not change the expression levels of gyrA and parC genes.. S. epidermidis strains isolated from three ocular pathologies were gatifloxacin and moxifloxacin resistant due to mutations on the gyrA and parC genes.

Topics: Anti-Infective Agents; Aza Compounds; Conjunctivitis; Corneal Ulcer; DNA Gyrase; DNA Topoisomerase IV; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Endophthalmitis; Eye Infections, Bacterial; Fluoroquinolones; Gatifloxacin; Humans; Microbial Sensitivity Tests; Moxifloxacin; Mutation; Quinolines; Reverse Transcriptase Polymerase Chain Reaction; Staphylococcus epidermidis