Effects of Metals on Antibiotic Resistance and Conjugal Plasmid Transfer in Soil Bacterial Communities

• Main Author: Song, Jianxiao
• Format: Book
• Language: English
• Published: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen 2017
• Subjects: permafrost
• Online Access: https://curis.ku.dk/portal/da/publications/effects-of-metals-on-antibiotic-resistance-and-conjugal-plasmid-transfer-in-soil-bacterial-communities(55585bb1-e867-4c01-a92b-67abe93833d9).html; https://soeg.kb.dk/permalink/45KBDK_KGL/fbp0ps/alma99122333680505763

Antibiotic resistance currently represents one of the biggest challenges for human health and in recent years the environmental dimension of antibiotic resistance has been increasingly recognized. The soil environment serves as an important reservoir of antibiotic resistance determinants. In addition to direct selection of antibiotic resistance by antibiotics, metals may co-select for antibiotic resistance via different mechanisms causing environmental selection of antibiotic resistance in metal contaminated soils. Horizontal gene transfer of mobile genetic elements (MGEs) like plasmids is generally considered one of the most important co-selection mechanisms as multiple resistance genes can be located on the same MGE. This PhD thesis focused on the impact of metals (Cu and Zn) on the development of antibiotic resistance in bacterial communities in soils exposed to different degrees of anthropogenic disturbance ranging from ‘pristine’ permafrost soils to highly contaminated agricultural soils. In addition, the effect of long term Cu contamination on soil bacterial community permissiveness towards conjugal plasmid uptake was investigated. In conclusion, the study demonstrates a potentially important role of metals for environmental selection of antibiotic resistance in soil bacterial communities. Co-selection by metals was observed both in ‘pre-antibiotic era’-like bacterial communities and in corresponding communities from highly anthropogenically affected agricultural soils. Long term adaptation to metal stress did not significantly increase the permissiveness of the soil bacterial community towards conjugal plasmid transfer.