AUTHOR=Lee Yu Jin , Jung Hye-Ri , Yoon Sunghyun , Lim Suk-Kyung , Lee Young Ju 

TITLE=Situational analysis on fluoroquinolones use and characterization of high-level ciprofloxacin-resistant Enterococcus faecalis by integrated broiler operations in South Korea

JOURNAL=Frontiers in Veterinary Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1158721

DOI=10.3389/fvets.2023.1158721

ISSN=2297-1769

ABSTRACT=<p>Fluoroquinolones are classified as “critically important antimicrobials for human medicine”; however, their extensive use in livestock poses a significant health risk to humans as it leads to the rapid spread of antimicrobial resistance. This study confirmed that 40.0%−71.4% of the farms in three of the five integrated broiler operations were administered ciprofloxacin (CIP). Moreover, preventive purposes (60.9%), veterinarian prescriptions (82.6%), drinking water route (100%), and 1 to 3 days (82.6%) of age were significantly highest (<italic>P</italic> &lt; 0.05). 194 high-level ciprofloxacin-resistant (HLCR) <italic>Enterococcus faecalis</italic> (<italic>E. faecalis</italic>) were found in 65 of 74 farms, and of which, the prevalence of <italic>qnrA</italic> (63.9%), <italic>tetM</italic> (60.3%), <italic>ermB</italic> (64.9%), <italic>blaz</italic> (38.7%), and <italic>catA</italic> (34.0%) was significantly highest (<italic>P</italic> &lt; 0.05). 154 (79.4%) isolates showed MDR, and the distribution of MDR was significantly differences among the operations (<italic>P</italic> &lt; 0.05). All HLCR <italic>E. faecalis</italic> possessed double mutations in <italic>gyrA</italic> and <italic>parC</italic>, and S83I/S80I (90.7%) mutations were most commonly identified. Interestingly, the distribution of isolates with MICs ≥ 512 for both CIP and moxifloxacin was significantly higher in CIP–administered farms (56.5%) than in non-CIP–administered farms (41.4%) (<italic>P</italic> &lt; 0.05). Also, the prevalence of strong or moderate biofilm formers in HLCR <italic>E. faecalis</italic> was significantly higher than that of weak and no biofilm formers (<italic>P</italic> &lt; 0.05). HLCR <italic>E. faecalis</italic> were heavily distributed in the broiler farms in Korea; therefore, it is necessary to minimize the prevalence of resistant bacteria <italic>via</italic> structural management regulations such as cleaning and disinfection of farm environments.</p>