Jourand Philippe auteur aut IRD Philippe A. auteur aut IRD Carret L. auteur aut IRD Moutoucomarapoule S. auteur aut IRD Crespel C. auteur aut IRD Leon L. auteur aut IRD Sababadichetty L. auteur aut IRD Thibault M. auteur aut IRD Majorel Clarisse auteur aut IRD Guilhaumon François auteur aut IRD Lenoble V. auteur aut IRD Jean C. auteur aut IRD Ciccione S. auteur aut IRD Barret M. auteur aut IRD Schneider F. auteur aut IRD Miltgen G. auteur aut IRD text journalArticle eng text/pdf born digital access Marine plastic debris provides a novel substrate for microbial colonization, potentially facilitating the spread of pathogens in marine environments. At Reunion Island (Southwest Indian Ocean), injured sea turtles undergoing rehabilitation at the Kelonia center were found to harbor antibiotic-resistant pathogenic bacteria. We hypothesized that these bacteria were originated from plastic debris present in the seawater pumping system. To investigate this, we isolated and characterized culturable bacteria from plastic fragments, seawater, and turtles. Bacterial identification was performed using 16S rDNA sanger sequencing, and multilocus phylogenetic analyses were conducted to assess genetic relatedness among isolates. Antimicrobial susceptibility testing (AST) was also carried out. Plastic debris, primarily composed of polypropylene and polyethylene, supported dense bacterial communities (105-107CFU/g), in contrast to seawater which contained significantly lower loads (up to 103 CFU/ ml). Among the potentially pathogenic bacteria, Enterococcus (22 %), Vibrio (16 %), Bacillus (16 %), Staphylococcus (9 %), and Citrobacter (6 %) were the most prevalent. Phylogenetic analyses revealed close relationships between strains from plastics and turtles, particularly for Bacillus, Citrobacter, and Enterococcus. Notably, Vibrio strains were undetected from seawater but detected on plastics and in turtles, suggesting a possible transmission route. Phenotypic antibiotic resistances, mainly to beta-lactams, were detected in 30 % of plastic-associated strains and 14 % of turtle strains. Our results suggest that plastic debris serve as a reservoir and vector for antimicrobial-resistant pathogens, potentially compromising turtle rehabilitation efforts. This potential transmission pathway may hinder the treatment of infected or injured turtles, posing a significant challenge to the conservation of these endangered species. specialized Marine plastic debris Antibiotic resistance Pathogen transmission Sea turtles Southwest Indian Ocean REUNION OCEAN INDIEN 021 034 038 084 215 107822 [13 p.] 2026 0141-1136 https://www.documentation.ird.fr/hor/fdi:010096034 10.1016/j.marenvres.2025.107822 0141-1136 [F B010096034] https://www.documentation.ird.fr/hor/fdi:010096034 https://www.documentation.ird.fr/intranet/publi/2026-02/010096034.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2026-02-04 2026-02-04 fdi:010096034 fre