Wild sea turtles as bioindicators of antibiotic exposure in the levantine basin

Sea turtles serve as vital bioindicators of marine ecosystem health, offering insights into environmental changes and the impact of human activities. This study explores the microbiota and antimicrobial resistance (AMR) profiles of potential pathogens in loggerhead ( caretta ) and green ( Chelonia mydas ) sea turtles from the Levantine Basin, representing the first such investigation in this region. Samples were collected from 23 turtles admitted to the Israeli Sea Turtle Rescue Center, with 93 Gram-negative bacterial isolates identified across respiratory, skin, and cloacal samples. Vibrio, Shewanella , and Psychrobacter were the dominant genera, with several isolates demonstrating resistance to beta-lactam antibiotics, including cefazolin (95 %), ampicillin (50 %), and amoxicillin-clavulanate (45 %). Multidrug resistance (MDR) was observed in 75 % of isolates, emphasizing the significant role of sea turtles as reservoirs of AMR pathogens. This highlights potential risks of zoonotic transmission during rehabilitation and underscores the broader implications of AMR in marine ecosystems, exacerbated by anthropogenic pollution. These findings underscore the necessity of monitoring microbial communities in marine wildlife and implementing targeted strategies to mitigate AMR spread. Future research should aim to identify antibiotic resistance genes (ARGs) and explore mechanisms such as quorum sensing that facilitate microbial communication and AMR propagation. Understanding these interactions could inform innovative approaches to combat AMR while preserving both marine and human health.