Different antibiotic profiles in wild and farmed Chilean salmonids. Which is the main source for antibiotic in fish?

CARRIZO, JUAN CRUZ; GRIBOFF, JULIETA; BONANSEA, ROCÍO INÉS; NIMPTSCH, JORGE; VALDÉS, MARÍA EUGENIA; WUNDERLIN, DANIEL ALBERTO; AMÉ, MARÍA VALERIA

THE SCIENCE OF TOTAL ENVIRONMENT

ELSEVIER

Año: 2021 vol. 800

0048-9697

Fish from both aquaculture and wild capture are exposed to veterinary and medicinal antibiotics (ABs). Thisstudy explored the occurrence and probable source of 46 antibiotic residues in muscle of farmed salmon andwild trout from Chile. Results showed that at least one AB was detected in all studied samples. Diverse patternswere observed between farmed and wild specimens, with higherABs concentrationsin wildfish. Considering an-timicrobial resistance, detected ABs corresponded to the categories B (Restrict), C (Caution) and D (Prudence)established by Antimicrobial Advice Ad Hoc Expert Group (European Medicines Agency). Multivariate statisticwas used to verify differences between farmed and wild populations, looking for the probable source of ABs aswell. Principal components analysis (PCA) revealed that ciprofloxacin, moxifloxacin, enrofloxacin, amoxicillin,penicillin G, oxolinic acid, sulfamethoxazole, trimethoprim and clarithromycin were associated with wildsamples, collected during the cold season. Conversely, norfloxacin, sulfaquinoxaline, sulfadimethoxine,nitrofurantoin, nalidixic acid, penicillin V, doxycycline,flumequine, oxacillin, pipemidic acid and sulfamethizolewere associated with wild samples collected during the warm season. All farmed salmon samples were associ-ated with ofloxacin, tetracycline, cephalexin, erythromycin, azithromycin, roxithromycin, sulfabenzamide, sulfa-methazine, sulfapyridine, sulfisomidin, and sulfaguanidine. In addition, linear discriminant analysis showed thatthe AB profilein wildfish differ from farmed ones. Most samples showed ABs levels below the EU regulatory limitfor ediblefish, except for sulfaquinoxaline in one sample. Additionally, nitrofurantoin (banned in EU) was de-tected in one aquaculture sample. The differences observed between farmed and wildfish raise questions onthe probable source of ABs, either aquaculture or urban anthropic activities. Further research is necessary for linking the ABs profile in wildfish with the anthropic source. However, to our knowledge, this is thefirst reportshowing differences in the ABs profile between wild and aquaculture salmonids, which could have both environ-mental and health consequences.