Fungal Networks Serve as Novel Ecological Routes for Enrichment and Dissemination of Antibiotic Resistance Genes as Exhibited by Microcosm Experiments

Author: mycolabadmin
2017-11-13
View Source

Summary

This research reveals that common soil fungi can help spread antibiotic-resistant bacteria and their resistance genes through soil environments. The fungi create networks of thread-like structures that act as highways for bacteria to travel along, potentially spreading antibiotic resistance to new areas. This has important implications for public health and environmental contamination. Impacts on everyday life: – Helps explain how antibiotic resistance can spread through agricultural soils – Suggests need for better management of manure and wastewater application to prevent resistance spread – Highlights importance of considering fungal presence when assessing environmental contamination risks – May lead to new strategies for controlling antibiotic resistance in agricultural settings – Demonstrates complex ecological interactions that affect human health

Background

Over recent decades, there has been an enormous increase in antibiotic use in clinics, agriculture and animal husbandry. This has led to microbes developing multiple drug resistance via antibiotic resistance genes (ARGs). Animal manure and wastewater treatment plants have been recognized as important reservoirs for environmental dissemination of ARGs. The spread of ARGs and their potential acquisition by pathogens poses a threat to human health, making it essential to understand their dissemination mechanisms.

Objective

To investigate the role of soil fungi in the distribution of bacteria with antibiotic resistance genes through soil microcosm experiments. Specifically, to explore: 1) the influences of fungal colonization on ARG abundance and antibiotic resistant bacteria communities, 2) effects of different manure-originating fungi on ARGs from manure and wastewater sources, and 3) if fungi can transport ARGs and resistant bacteria through soil via mycelial networks.

Results

The qPCR assay detected unique ARGs specifically found in the mycosphere of different fungi. Different fungi exerted varying selection pressures on ARGs from the same source. The fungi supported different antibiotic resistant bacteria enriched in the mycosphere and transported them to distant locations. The relative abundance of the tnpA gene decreased along mycelial networks for all fungi with manure source. The fungal strain NFC-5 enriched the intI1 gene more compared to other fungi at the migration front. Network analyses revealed different co-occurrence patterns of ARGs under fungal influence.

Conclusion

The study provides first evidence that soil fungi can contribute to ARG distribution by affecting host bacterial diversity and abundance. The fungal-bacterial consortia have the potential to disseminate resistance determinants through soil, increasing ARG exposure risk to humans. Different fungi showed differential effects on ARG patterns and transmission factors, emphasizing the importance of considering fungal presence when assessing risks associated with ARG spread in environments.

Published in:Scientific Reports,
Study Type:Laboratory Microcosm Experiment,
Source: 10.1038/s41598-017-15660-7