Ampicillin in Soil? Earthworms to the Rescue!

by: Hania De La Fuente

The image displays two line graphs comparing the effects of ampicillin on soil and earthworms over 17 days. Graph (A) shows the concentration of ampicillin in soil and in soil with earthworms, while graph (B) illustrates the weight changes in earthworms over time. Figure taken from Gao et al. 2024.

    Antibiotics are used in cattle farming to ensure livestock health, but their overuse and the use of cattle dung as fertilizer have led to the accumulation of antibiotic-resistant genes (ARGs) in soil and wastewater, making pathogens in these areas multi-drug resistant and posing a significant threat to human health. This issue alarmed researchers Gao and colleagues, who then performed an experiment striving to decrease the contamination of ARGs in soil using very common soil dwellers: earthworms! The researchers placed earthworms in both uncontaminated and ampicillin-contaminated soils, observing that the earthworms in the contaminated soil gained weight more rapidly during the first few days of the experiment. The concentration of ampicillin and ARGs were also reduced in the soil containing earthworms. Moreover, the microbial population in the soil was altered by the presence of earthworms, with increased populations of the bacterial species Proteobacteria and Cyanobacteria being observed. These effects led to the conclusion that not only do the earthworms decrease the ampicillin concentration of the soil, reduce the presence of ARGs, and modify the soil’s microbiota, but they also prosper in the contaminated soil, as evidenced by their weight gain. These results show that using earthworms for bioremediation is an eco-friendly and cost-effective method to clean contaminated soils. They also show how earthworms mitigate the environmental impact of antibiotic overuse in livestock farming. This study highlights the potential of using natural bioremediation methods, such as earthworms, to address the growing environmental and public health challenges posed by antibiotic overuse in agriculture.

Citation:

Gao X, Zhang H, Xu L, Wang L, Li X, Jiang Y, Yu H,  Zhu G. 2024. Impact of earthworms on antibiotic resistance genes removal in ampicillin‐contaminated soil through bacterial community alteration. J Environ Qual 53(4):521-534.