Identifying macroplastic pathobiomes and antibiotic resistance in a subtropical fish farm

Macroplastics are ubiquitous in aquaculture ecosystems. However, to date the potential role of plastics as a support for bacterial biofilm that can include potential human pathogenic bacteria (PHPB) and antibioticresistant bacteria (ARB) has been largely overlooked. In this study, we used a combination of metabarcoding and standard antibiotic susceptibility testing to study the pathobiome and resistome of macroplastics, fish guts and the environment in a marine aquaculture farm in Mauritius. Aquaculture macroplastics were found to be higher in PHPB, dominated by the Vibrionaceae family (0.34 % of the total community), compared with environmental samples. Moreover, isolates from aquaculture plastics showed higher significant multiple antibiotic resistance (MAR) compared to non-plastic samples of seawater, sediment and fish guts. These results suggest that plastics act as a reservoir and fomite of PHPB and ARB in aquaculture, potentially threatening the health of farmed fish and human consumers.

Automated summary

This study reveals that macroplastics commonly found in aquaculture can serve as a habitat for bacterial biofilm, including potential human pathogens and antibiotic-resistant bacteria. The presence of pathogenic and resistant bacteria was significantly higher in plastic samples compared to environmental samples, posing a potential threat to the health of farmed fish and human consumers.