Susceptibility of Contemporary Staphylococcus aureus Isolates to a Novel Antibiotic Levonadifloxacin: A Report from a Tertiary Care Center

Abstract

ABSTRACT Background: Levonadifloxacin and its oral prodrug, Alalevonadifloxacin, are novel antibiotics licensed in India for the treatment of acute bacterial skin and soft tissue infections, including diabetic foot infections and concurrent bacteremia. Objective: The objective of this study is to assess the activity of levonadifloxacin against contemporary Staphylococcus aureus clinical isolates, including methicillin-resistant S. aureus (MRSA). Methods: A total of 102 S. aureus isolates (non-duplicate one per patient from diverse specimens) were collected from January to December 2021. Isolates were further screened for methicillin-resistance by the disk-diffusion method using Cefoxitin (30 mcg). Susceptibilities of levonadifloxacin and other antibiotics were then determined using the disk-diffusion method performed as per the recommendations of the Clinical and Laboratory Standards Institute. Results: Among 102 isolates, 49 (57.8%) were MRSA. Against all isolates, the susceptibilities to gentamicin, cotrimoxazole, erythromycin, clindamycin, and ciprofloxacin were 61.8, 60, 30.4, 57.8, and 12.7%, respectively, while levonadifloxacin showed 100% susceptibility. Furthermore, the susceptibilities of linezolid and vancomycin were also 100%. Conclusion: Levonadifloxacin is a newer, safer, and alternative treatment option for infections caused by diverse multidrug-resistant S. aureus, including MRSA. This study, in conjunction with other previous studies, also re-established that levonadifloxacin susceptibilities can be reliably determined using the disk-diffusion method.