TY - JOUR
AU - Pichon, Maxime
AB - BackgroundIncreasing antibiotic resistance in Helicobacter pylori necessitates research on new active molecules. In 2017, delafloxacin, a new fluoroquinolone with chemical properties of activity under acidic conditions, was approved for treatment of community-acquired bacterial pneumonia and acute bacterial skin and soft-tissue infections. Mutations in gyrA are responsible for fluoroquinolone resistance, but certain clinical isolates of H. pylori appear to display a dual phenotype: resistance to levofloxacin associated with very low delafloxacin MICs.ObjectivesTo estimate epidemiological cut-off (ECOFF) values and to identify mutations in the gyrA gene, specific to FQ resistance, without increasing the MICs of delafloxacin.MethodsClinical strains (n = 231) were collected in the bacteriology laboratory of Poitiers University Hospital over a 2 year period to determine the ECOFF of delafloxacin. Retrospectively, 101 clinical strains with an levofloxacin-resistant phenotype (MIC > 1 mg/L) were selected from 2018 to 2022 for delafloxacin MIC determination and QRDR (gyrA) sequencing.ResultsThe estimated ECOFF of delafloxacin was ≤0.125 mg/L. No H. pylori isolate showed a levofloxacin-sensitive phenotype with a delafloxacin MIC of >0.125 mg/L. Among the levofloxacin-resistant H. pylori isolates, 53.5% had delafloxacin MICs of ≤0.125 mg/L. The N87I mutation was associated with dual levofloxacin/delafloxacin resistance (P < 0.001) in contrast to the N87K and D91N mutations (P > 0.05). Mutations D91G and D91Y were not associated with a delafloxacin resistance phenotype (P > 0.05).ConclusionsDelafloxacin seems to be a therapeutic alternative for levofloxacin-resistant strains with greater in vitro activity. However, further clinical/biological investigations are required to determine its efficacy in H. pylori eradication.
TI - In vitro activity of delafloxacin against clinical levofloxacin-resistant Helicobacter pylori isolates
JO - Journal of Antimicrobial Chemotherapy
DO - 10.1093/jac/dkae269
DA - 2024-08-10
UR - https://www.deepdyve.com/lp/oxford-university-press/in-vitro-activity-of-delafloxacin-against-clinical-levofloxacin-bjtwQv5Rft
SP - 2633
EP - 2639
VL - 79
IS - 10
DP - DeepDyve
ER -