Genetic Determinants and Clonal Composition of Levofloxacin-Resistant <i>Streptococcus agalactiae</i> Isolates from Bulgaria.

ABSTRACT: Background: Levofloxacin is a broad-spectrum third-generation fluoroquinolone with bactericidal activity against Streptococcus species. We aimed to investigate the susceptibility rates of levofloxacin, the genetic determinants contributing to resistance, the serotype distribution, and the population structure of levofloxacin-resistant Streptococcus agalactiae (GBS) isolates. Methods: Antibiotic susceptibility testing was conducted according to the EUCAST criteria. PCR-serotyping, determination of mutations in the quinolone resistance-determining regions (QRDRs), and multi-locus sequence typing (MLST) were performed on all levofloxacin-resistant strains. Results: Among the 328 GBS isolates, 11.9% exhibited resistance to levofloxacin. We categorized the sam

SUBMITTER: Boyanov VS 

PROVIDER: S-EPMC12649546 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature