Plastic debris is creating superbugs!

Microplastics, metals and antibiotics are ubiquitous, accumulating contaminants inflicting adverse impacts on aquatic ecosystems. But how do these pollutants all link? Yang et al. (2019) proposed that the marine plastics act as a reservoir for metal resistance genes (MRGs) and antibiotic resistance genes (ARGs), as they become vectors for pollutants and bacteria, promoting resistance and increasing the exchange of genes. 

Using metagenomic data for microbial communities on plastic debris found in the North Pacific Gyre, the abundance and diversity of ARGs and MRGs in bacterial taxa on plastics was determined. The presence of ARGs and MRGs occurred on all plastic samples, with greater diversity of ARG and MRG subtypes in the plastic biota. The genes identified provided resistance to 13 different antibiotics and 11 metals, far fewer subtypes were found in seawater controls. Non-random co-occurrence patterns of resistance genes was observed, MRGs and ARGs are co-selected as they share regulation factors and can be co-transferred. 

This paper highlights the contribution of marine plastic pollution to increasing the occurrence, diversity and spread of antibiotic resistance, the wider significance being that anthropogenic pollution is promoting the spread of multi-drug resistance amongst bacteria, hence will inevitably accelerate the day when antibiotics become ineffective.

Yang, Y., Liu, G., Song, W., Ye, C., Lin, H., Li, Z., & Liu, W. (2019). Plastics in the marine environment are reservoirs for antibiotic and metal resistance genes. Environment international, 123, 79-86.