<abstract xmlns="http://www.w3.org/1999/xhtml">The widespread of infections caused by methicillin-resistant <italic>Staphylococcus aureus</italic> (MRSA), has necessitated the search for alternative therapies; introduction of new agents being a suggestion. This study compares the <italic>in vitro</italic> and <italic>in vivo</italic> activities of zabofloxacin, a novel fluoroquinolone, with moxifloxacin, levofloxacin and ciprofloxacin against clinical isolates of MRSA from patients hospitalized in the Alexandria Main University hospital; a tertiary hospital in Alexandria, Egypt, where zabofloxacin has not been yet introduced. The strains tested showed the highest percentage of susceptibility to zabofloxacin (61.2%) among the tested fluoroquinolones with the most effective MIC50 and MIC90 (0.25 and 2 µg/ml, respectively). Time-kill curve analysis revealed a rapid bactericidal activity of zabofloxacin after 6 h of incubation with a quinolone-resistant isolate and complete killing when tested against a quinolone-sensitive isolate with inhibition of regrowth in both cases. PCR amplification and sequencing of QRDRs in selected strains revealed the following amino acid substitutions: Ser-84→Leu in GyrA, Ser-80→Phe in GrlA and Pro-451→Ser in GrlB. The <italic>in vivo</italic> studies demonstrated that zabofloxacin possessed the most potent protective effect against systemic infection in mice (ED50: 29.05 mg/kg) with lowest count in the dissected lungs (3.66 log10 CFU/ml). The histopathological examination of lung specimens of mice treated with zabofloxacin displayed least congestion, inflammation, oedema and necrosis with clear alveolar spaces and normal vessels. In conclusion, zabofloxacin was proved to possess high <italic>in vitro</italic> and <italic>in vivo</italic> efficacy encompassing its comparators and could be considered as a possible candidate for the treatment of infections caused by MRSA. To our knowledge, this is the first study evaluating the <italic>in vitro</italic> and <italic>in vivo</italic> activity of zabofloxacin against Egyptian MRSA clinical isolates.</abstract>

The widespread of infections caused by methicillin-resistant Staphylococcus aureus (MRSA), has necessitated the search for alternative therapies; introduction of new agents being a suggestion. This study compares the in vitro and in vivo activities of zabofloxacin, a novel fluoroquinolone, with moxifloxacin, levofloxacin and ciprofloxacin against clinical isolates of MRSA from patients hospitalized in the Alexandria Main University hospital; a tertiary hospital in Alexandria, Egypt, where zabofloxacin has not been yet introduced. The strains tested showed the highest percentage of susceptibility to zabofloxacin (61.2%) among the tested fluoroquinolones with the most effective MIC50 and MIC90 (0.25 and 2 µg/ml, respectively). Time-kill curve analysis revealed a rapid bactericidal activity of zabofloxacin after 6 h of incubation with a quinolone-resistant isolate and complete killing when tested against a quinolone-sensitive isolate with inhibition of regrowth in both cases. PCR amplification and sequencing of QRDRs in selected strains revealed the following amino acid substitutions: Ser-84→Leu in GyrA, Ser-80→Phe in GrlA and Pro-451→Ser in GrlB. The in vivo studies demonstrated that zabofloxacin possessed the most potent protective effect against systemic infection in mice (ED50: 29.05 mg/kg) with lowest count in the dissected lungs (3.66 log10 CFU/ml). The histopathological examination of lung specimens of mice treated with zabofloxacin displayed least congestion, inflammation, oedema and necrosis with clear alveolar spaces and normal vessels. In conclusion, zabofloxacin was proved to possess high in vitro and in vivo efficacy encompassing its comparators and could be considered as a possible candidate for the treatment of infections caused by MRSA. To our knowledge, this is the first study evaluating the in vitro and in vivo activity of zabofloxacin against Egyptian MRSA clinical isolates.

<italic>In Vitro</italic> and <italic>In Vivo</italic> Activity of Zabofloxacin and Other Fluoroquinolones Against MRSA Isolates from A University Hospital in Egypt

Polish Journal of Microbiology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

 and  Activity of Zabofloxacin and Other Fluoroquinolones Against MRSA Isolates from A University Hospital in Egypt

The widespread of infections caused by methicillin-resistant Staphylococcus aureus (MRSA), has necessitated the search for alternative therapies; introduction...

In Vitro and In Vivo Activity of Zabofloxacin and Other Fluoroquinolones Against MRSA Isolates from A University Hospital in Egypt

Article Category: original-paper

Published Online: Mar 27, 2019

Page range: 59 - 69

DOI: https://doi.org/10.21307/pjm-2019-007

Keywords
MRSA, ED50, fluoroquinolones, quinolone resistance-determining regions, zabofloxacin

© 2019 Maryam Labibzadeh et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

In Vitro and In Vivo Activity of Zabofloxacin and Other Fluoroquinolones Against MRSA Isolates from A University Hospital in Egypt

Article Category: original-paper

Published Online: Mar 27, 2019

Page range: 59 - 69

DOI: https://doi.org/10.21307/pjm-2019-007

KeywordsMRSA, ED50, fluoroquinolones, quinolone resistance-determining regions, zabofloxacin

© 2019 Maryam Labibzadeh et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
MRSA, ED50, fluoroquinolones, quinolone resistance-determining regions, zabofloxacin