RT Journal Article T1 Persistence of antibiotic resistant Vibrio spp. in shellfish hatchery environment A1 Dubert Pérez, Javier A1 Rodríguez Osorio, Carlos A1 Prado Plana, Susana A1 Barja Pérez, Juan Luis AB The characterization of antibiotic-resistant vibrios isolated from shellfish aquaculture is necessary to elucidate the potential transfer of resistance and to establish effective strategies against vibriosis. With this aim, we analyzed a collection of bacterial isolates obtained from 15 failed hatchery larval cultures that, for the most part, had been treated experimentally with chloramphenicol to prevent vibriosis. Isolates were obtained during a 2-year study from experimental cultures of five different clam species. Among a total of 121 Vibrio isolates studied, 28 were found to be chloramphenicol resistant, suggesting that the shellfish hatchery had been using a sublethal concentration of the antibiotic. Interestingly, chloramphenicol-resistant vibrios showed also resistance to tetracycline and amoxicillin (group A; n = 19) or to streptomycin (group B; n = 9). Chloramphenicol-resistant vibrios were subjected to a PCR amplification and DNA sequencing of the chloramphenicol acetyltransferase genes (cat), and the same approach was followed to study the tetracycline resistance markers (tet). 16S ribosomal RNA (rRNA) gene sequencing revealed that chloramphenicol-resistant vibrios pertained mostly to the Splendidus clade. Conjugation assays demonstrated that various R-plasmids which harbored the cat II/tet(D) genes and cat III gene in groups A and B respectively, were transferred to E. coli and bivalve pathogenic vibrios. Most interestingly, transconjugants exhibited the antibiotic resistance patterns of the donors, despite having been selected only on the basis of chloramphenicol resistance. This is the first report carried out in a bivalve hatchery elucidating the persistence of resistant v PB Springer SN 0095-3628 YR 2016 FD 2016-11-01 LK https://hdl.handle.net/10347/38795 UL https://hdl.handle.net/10347/38795 LA eng NO Dubert, J., Osorio, C.R., Prado, S. et al. Persistence of Antibiotic Resistant Vibrio spp. in Shellfish Hatchery Environment. Microb Ecol 72, 851–860 (2016). https://doi.org/10.1007/s00248-015-0705-5 NO This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s00248-015-0705-5 NO AGL2011-29765 y AGL2014-59655 del Ministerio de Economía y Competitividad (Gobierno de España). DS Minerva RD 24 abr 2026