{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T18:45:57Z","timestamp":1781203557907,"version":"3.54.1"},"reference-count":52,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2021,12,12]],"date-time":"2021-12-12T00:00:00Z","timestamp":1639267200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Red Espanola de Investigacion en Patologia Infecciosa","award":["RD16\/0016\/0010"],"award-info":[{"award-number":["RD16\/0016\/0010"]}]},{"name":"Strategic Action on Health","award":["PI17\/01468"],"award-info":[{"award-number":["PI17\/01468"]}]},{"name":"Agency for Management of University and Research Grants of the Catalan Government","award":["SGR 0809"],"award-info":[{"award-number":["SGR 0809"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The big problem of antimicrobial resistance is that it requires great efforts in the design of improved drugs which can quickly reach their target of action. Studies of antibiotic uptake and interaction with their target it is a key factor in this important challenge. We investigated the accumulation of ozenoxacin (OZN), moxifloxacin (MOX), levofloxacin (LVX), and ciprofloxacin (CIP) into the bacterial cells of 5 species, including Staphylococcus aureus (SA4-149), Staphylococcus epidermidis (SEP7602), Streptococcus pyogenes (SPY165), Streptococcus agalactiae (SAG146), and Enterococcus faecium (EF897) previously characterized.The concentration of quinolone uptake was estimated by agar disc-diffusion bioassay. Furthermore, we determined the inhibitory concentrations 50 (IC50) of OZN, MOX, LVX, and CIP against type II topoisomerases from S. aureus.The accumulation of OZN inside the bacterial cell was superior in comparison to MOX, LVX, and CIP in all tested species. The accumulation of OZN inside the bacterial cell was superior in comparison to MOX, LVX, and CIP in all tested species. The rapid penetration of OZN into the cell was reflected during the first minute of exposure with antibiotic values between 190 and 447 ng\/mg (dry weight) of bacteria in all strains. Moreover, OZN showed the greatest inhibitory activity among the quinolones tested for both DNA gyrase and topoisomerase IV isolated from S. aureus with IC50 values of 10 and 0.5 mg\/L, respectively. OZN intracellular concentration was significantly higher than that of MOX, LVX and CIP. All of these features may explain the higher in vitro activity of OZN compared to the other tested quinolones.<\/jats:p>","DOI":"10.3390\/ijms222413363","type":"journal-article","created":{"date-parts":[[2021,12,13]],"date-time":"2021-12-13T01:28:11Z","timestamp":1639358891000},"page":"13363","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Uptake of Ozenoxacin and Other Quinolones in Gram-Positive Bacteria"],"prefix":"10.3390","volume":"22","author":[{"given":"Yuly","family":"L\u00f3pez","sequence":"first","affiliation":[{"name":"Institute of Global Health of Barcelona, 08036 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Mu\u00f1oz","sequence":"additional","affiliation":[{"name":"Institute of Global Health of Barcelona, 08036 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Domingo","family":"Gargallo-Viola","sequence":"additional","affiliation":[{"name":"ABAC Therapeutics, 08950 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1675-3173","authenticated-orcid":false,"given":"Rafael","family":"Cant\u00f3n","sequence":"additional","affiliation":[{"name":"Department of Clinical Microbiology, Hospital Universitario Ram\u00f3n y Cajal & Instituto Ram\u00f3n y Cajal de Investigaci\u00f3n Sanitaria (IRYCIS), 28034 Madrid, Spain"},{"name":"CIBER Enfermedades Infecciosas, ISCIII, 28029 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8025-3926","authenticated-orcid":false,"given":"Jordi","family":"Vila","sequence":"additional","affiliation":[{"name":"Institute of Global Health of Barcelona, 08036 Barcelona, Spain"},{"name":"CIBER Enfermedades Infecciosas, ISCIII, 28029 Madrid, Spain"},{"name":"Department of Clinical Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, 08007 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8900-722X","authenticated-orcid":false,"given":"Ilonka","family":"Zsolt","sequence":"additional","affiliation":[{"name":"Ferrer International, 08029 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Sarker, S.D., Latif, Z., and Gray, A.I. 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