In Vitro Activity of Delafloxacin and Finafloxacin against Mycoplasma hominis and Ureaplasma Species

Yingying Kong; Chao Li; Gangfeng Li; Ting Yang; Mohamed S. Draz; Xinyou Xie; Jun Zhang; Zhi Ruan

doi:10.1128/spectrum.00099-22

Microbiology Spectrum (Jun 2022)

In Vitro Activity of Delafloxacin and Finafloxacin against Mycoplasma hominis and Ureaplasma Species

Yingying Kong,
Chao Li,
Gangfeng Li,
Ting Yang,
Mohamed S. Draz,
Xinyou Xie,
Jun Zhang,
Zhi Ruan

Affiliations

Yingying Kong: Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
Chao Li: Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
Gangfeng Li: Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
Ting Yang: Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
Mohamed S. Draz: Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
Xinyou Xie: Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
Jun Zhang: Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
Zhi Ruan: Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China

DOI: https://doi.org/10.1128/spectrum.00099-22
Journal volume & issue: Vol. 10, no. 3

Abstract

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ABSTRACT The in vitro activity of two new fluoroquinolones, delafloxacin and finafloxacin, were evaluated against M. hominis and Ureaplasma spp. The MICs of delafloxacin, finafloxacin, and two classical fluoroquinolones (moxifloxacin and levofloxacin) were tested against 29 M. hominis and 67 Ureaplasma spp. isolates using the broth microdilution method. The molecular mechanisms underlying fluoroquinolone resistance were also investigated. Delafloxacin exhibited low MICs against M. hominis and Ureaplasma spp., including the levofloxacin-resistant isolates. For M. hominis, delafloxacin showed low MIC90 value of 1 μg/mL (MIC range, 32 μg/mL for levofloxacin. The two mutations GyrA S153L and ParC S91I were commonly identified in fluoroquinolone-resistant M. hominis, and ParC S83L was the most frequent mutation identified in fluoroquinolone-resistant Ureaplasma spp. Delafloxacin displayed lower MICs against fluoroquinolone-resistant isolates of both M. hominis and Ureaplasma spp. that have mutations in the quinolone resistance determining regions (QRDRs) than the two classical fluoroquinolones. Delafloxacin is a promising fluoroquinolone with low MICs against fluoroquinolone-resistant M. hominis and Ureaplasma spp. Our study confirms the potential clinical use of delafloxacin in treating antimicrobial-resistant M. hominis and Ureaplasma spp. infections. IMPORTANCE Fluoroquinolone resistance in Mycoplasma hominis and Ureaplasma spp. is on the rise globally, which has compromised the efficacy of the currently available antimicrobial agents. This study evaluated the antimicrobial activity of two new fluoroquinolones, delafloxacin and finafloxacin, for the first time, against M. hominis and Ureaplasma spp. clinical isolates. Delafloxacin and finafloxacin displayed different antimicrobial susceptibility profiles against M. hominis and Ureaplasma spp. in vitro. Delafloxacin was found to be more effective against M. hominis and Ureaplasma spp. than three classical fluoroquinolones (finafloxacin, moxifloxacin, and levofloxacin). Finafloxacin displayed activity similar to moxifloxacin but superior to levofloxacin against M. hominis and Ureaplasma spp. Our findings demonstrate that delafloxacin is a promising fluoroquinolone with outstanding activity against fluoroquinolone-resistant M. hominis and Ureaplasma spp.

Published in Microbiology Spectrum

ISSN: 2165-0497 (Online)
Publisher: American Society for Microbiology
Country of publisher: United States
LCC subjects: Science: Microbiology
Website: https://journals.asm.org/journal/spectrum

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