Invitro activity of levonadifloxacin against clinical isolates of Staphylococcus aureus from a tertiary center

Background: Levonadifloxacin, a novel broad-spectrum antibiotic belonging to the benzoquinolizine subclass of quinolone, has found use as an excellent drug to counter methicillin resistant Staphylococcus aureus (MRSA). Slow bactericidal activity, nephrotoxicity, high cost etc. limits the therapeutic value of vancomycin and linezolid. Levonadifloxacin has shown established best-in-class human epithelial lung fluid concentration, has promising potential in the management of recalcitrant respiratory infections and for the treatment of difficult-to-treat MRSA infections. Aim: To estimate the prevalence of MRSA among S.aureus isolates, from outpatients and inpatients admitted in a tertiary care center and to determine the in-vitro activity of levonadifloxacin against S. aureus isolates recovered from clinical samples. Methods: This prospective study was carried out on 201 isolates of S. aureus. Of the 201 S. aureus tested, antimicrobial susceptibility was performed on Mueller Hinton agar plates by the Kirby-Bauer disk diffusion method according to CLSI guidelines. Methicillin resistance was evaluated by using cefoxitin (30 μg) discs. Levonadifloxacin discs were used for all the S. aureus isolates. S. aureus ATCC 25923 strain was used as a standard quality control strain for the disc diffusion test. Results: A total of 201 samples from which S. aureus was isolated were included in the study. A total of 143(71.1%) were methicillin-resistant S. aureus. All the isolates were uniformly sensitive to vancomycin, teicoplanin and linezolid (100%) in addition to levonadifloxacin(100%). Conclusions: This study supports potential use of levonadifloxacin both as an empirical as well as a therapeutic agent in the treatment of infections caused by MRSA organisms.