activity of ozenoxacin against and clinical isolates recovered in a worldwide multicentre study (2020-2022).

OBJECTIVES

We performed a multicentre study (2020-2022) to compare the activity of ozenoxacin and comparator agents against and clinical isolates from skin and soft-tissue infections (SSTI).

METHODS

A total of 1725 isolates (1454 and 271 ) were collected in 10 centres from eight countries between January 2020 and December 2022. Antimicrobial susceptibility testing was determined (microdilution-SENSITITRE). Results were interpreted following European Committee on Antimicrobial Susceptibility Testing (EUCAST) 2023 (clinical breakpoints, ECOFF) and CLSI criteria.

RESULTS

Ozenoxacin exhibited high activity against (MIC = 0.002/0.12 mg/L) and (MIC = 0.015/0.03 mg/L), inhibiting 99% of the isolates at MIC ≤ 0.5 mg/L and at MIC ≤ 0.06, respectively. The most active comparators against were retapamulin (MIC = 0.12 mg/L), fusidic acid (MIC = 0.25 mg/L) and mupirocin (MIC = 0.5 mg/L); and against were retapamulin (MIC = 0.03 mg/L), clindamycin (MIC = 0.12 mg/L) and mupirocin (MIC = 0.25 mg/L). Ciprofloxacin and methicillin resistant rates for were 31.3% (455/1454) and 41% (598/1454), respectively. Additionally, 62% (373/598) of the MRSA were also ciprofloxacin non-susceptible, whereas only 10% (23/271) of the MSSA were ciprofloxacin resistant. Ozenoxacin was more active against ciprofloxacin-susceptible than against ciprofloxacin-resistant isolates, and showed a slightly higher MIC in MRSA isolates than in MSSA. However, ozenoxacin activity was comparable in both ciprofloxacin-resistant MSSA and MRSA subsets. On the other hand, ozenoxacin had similar activity in ciprofloxacin-susceptible and resistant isolates.

CONCLUSIONS

Ozenoxacin is a potent antimicrobial agent of topic use against Gram-positive bacteria causing SSTI, including MRSA isolates non-susceptible to ciprofloxacin.