“With microplasty we refer to small particles of plastic material generally smaller than 5 millimeters up to the micrometric level. The pollution from microplastics caused by very small waste that infiltrate the environment and in food is considered a threat to the ecosystem and human health” (Wikipedia)
These tiny plastic particles that disperse in the environment have now become a global problem that impacts marine and terrestrial ecosystems.
Today we will illustrate a less known aspect of the phenomenon that concerns their role in the increase in antibiotic resistance. It is a recent study conducted by a group of Italian researchers, including Enea, the Joint Research Center of the European Commission, the Crea Agriculture and Environment Center, and the Universities of Milan and Tuscia. The research revealed that microplastics in the ground can constitute a prolific channel for antibiotic-resistant bacteria. This therefore promotes significant dangers related to infections that are difficult to treat.
The interaction between microplastics and antibiotics
«Microplastics are often present in environments contaminated with antibiotics such as agricultural soils treated with fertilizers and waste water. This creates a selective pressure that promotes the survival and proliferation of resistant bacteria, increasing the spread of antibiotic resistance genes “, Annamaria Bevivino of the Enea division of sustainable agri -food systems said. “For their structure and composition, in fact, the very small plastic fragments offer resistant ‘ideal’ surfaces to form real microbial communities that favor the transfer of antibiotic resistance genes”, specified Bevivino.
The study identified four main bacteria that tend to colonize the surface of the microplastics dispersed in the environment. These bacteria are able not only to degrade microplastics, but also to transfer genes of resistance to antibiotics with each other. Andrea Visca, a researcher Enea of the innovation laboratory of the agri -food supply chains, suggests that these bacteria «they could be used as bioindicators to monitor soil health and the ecological impact linked to microplastical contamination».
Microplastics and degradation of plastic materials
To better understand how microplastics affect antibiotics resistance, researchers analyzed the bacterial DNA in 885 soil samples from different European Union countries. The results revealed that a type of bacterial gene is involved in the degradation of plastic materials. Among these compounds we find the scholar, benzoate, benzene and xylene. Present in different types of plastic, including polystyrene and the pet (polyethylene tereftolato). The “Cate” gene (we never put the apostrophe instead of high quotation marks, takes it as an error), associated with the degradation of the plastic material, has been identified as one of the most relevant in the process of removing microplastics in the soil.
The consequences for food safety and the quality of the soil
The accumulation of microplastics in agricultural soil does not only have ecological consequences, but also impacts agricultural productivity and food safety. In fact, these modify the physical and chemical properties of the soil, compromising the quality of the soil.
«At the moment, some studies have found a reduction in the yield of crops between 11% and 24% in agricultural soils where a high concentration of microplastic residues has been measured “report Annamaria Bevivino.
According to FAO about 30% of the world soil is subject to degradation, with losses of agricultural productivity that reach 40 billion dollars every year. In Europe, the phenomenon is even more accentuated, with over 60% of the soils degraded due to pollution, urbanization and the effects of climate change. The intensive use of the soil, together with the massive use of chemical and organic fertilizers, is increasing the concentration of microplastics in the ground, altering the composition of the microbial communities and putting at risk the vital ecosystem functions for agriculture.
It is essential that environmental and health policies work together to monitor the spread of microplastics and to reduce the risks associated with antibiotic-resistance.
Source: Enea