Bactericidal activity of besifloxacin against staphylococci, Streptococcus pneumoniae and Haemophilus influenzae
| Autor: | Chris M. Pillar, Christine K. Hesje, Wolfgang Haas, Timothy W. Morris, Christine M Sanfilippo |
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| Rok vydání: | 2010 |
| Předmět: |
DNA
Bacterial Microbiology (medical) Time Factors time–kill medicine.drug_class Staphylococcus bactericidal activity Microbial Sensitivity Tests beta-Lactams medicine.disease_cause Haemophilus influenzae Microbiology Moxifloxacin Staphylococcus epidermidis Drug Resistance Bacterial Streptococcus pneumoniae medicine Humans Pharmacology (medical) fluoroquinolones Original Research Antibacterial agent Pharmacology Microbial Viability biology Besifloxacin Azepines Sequence Analysis DNA Conjunctivitis Quinolone biology.organism_classification Virology Anti-Bacterial Agents Ciprofloxacin Aminoglycosides Infectious Diseases Genes Bacterial Macrolides medicine.drug |
| Zdroj: | Journal of Antimicrobial Chemotherapy |
| ISSN: | 1460-2091 0305-7453 |
| DOI: | 10.1093/jac/dkq127 |
| Popis: | Objectives Besifloxacin is a novel fluoroquinolone that was recently approved for topical treatment of bacterial conjunctivitis. The compound was shown to be active in vitro against a broad spectrum of bacteria, including isolates resistant to other antibacterials. Here, the bactericidal activity of besifloxacin was evaluated against the most common bacterial conjunctivitis pathogens. Methods MIC, MBC and time–kill experiments with besifloxacin and comparators were performed according to CLSI guidelines. Quinolone resistance-determining regions (QRDRs) were sequenced using standard PCR-based techniques. Results MIC and MBC data indicated that besifloxacin was the most potent fluoroquinolone tested against Staphylococcus aureus (n = 30), Staphylococcus epidermidis (n = 15) and Streptococcus pneumoniae (n = 35), while all fluoroquinolones were highly active against Haemophilus influenzae (n = 40). Besifloxacin MBC:MIC ratios were ≤4 for 97.5% of all isolates tested (n = 120). All fluoroquinolones tested, as well as tobramycin, were bactericidal, while azithromycin was bactericidal against S. pneumoniae and H. influenzae, but bacteriostatic against the staphylococci. Time–kill assays with all four species showed that besifloxacin caused ≥1000-fold killing within 2 h for 11 of 12 isolates. Only one isolate treated with moxifloxacin and three ciprofloxacin-treated isolates achieved the same level of bactericidal activity under the same conditions. Unlike the comparator fluoroquinolones, besifloxacin maintained a high potency and bactericidal activity even against strains that contained multiple mutations in the genes encoding DNA gyrase and topoisomerase IV. Conclusions Overall, besifloxacin demonstrated rapid bactericidal activity against the four major human pathogens tested here, including isolates that showed in vitro resistance to other fluoroquinolones, β-lactams, macrolides or aminoglycosides. |
| Databáze: | OpenAIRE |
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