Tanel Tenson, University of Tartu
Veljo Kisand, University of Tartu
Célia Maria Manaia Rodrigues, Universidade Católica Portuguesa, Portugal
The discovery and usage of antibiotics has changed the outcome for many diseases and operations for the best. The early excitement of defeating infectious diseases has turned to worries about the wide spread of resistance to antibiotics and their treatment. The wide usage of antibiotics in medicine, veterinary medicine, agriculture, and aquaculture is the main culprit for this wide and fast dissemination of resistance through the world. Although, antibiotic resistance causes problems in human related settings, resistance itself has not emerged with the use of antibiotics by man. Resistance has existed in the environment for millions of years and lately more and more attention is turned to finding out if and which connections there exist between the environmental and human related resistomes, which is the collection of known, unknown, and potential antibiotic resistance genes. In connection to this I have described in my research a cultivatable population of antibiotic resistant bacteria from the river Suur-Emajõgi. I found that many of the bacteria were resistant to more than one antibiotic and I also saw interesting and statistically significant correlations between different resistances which can hint at a mobile element or an efflux pump. I also found a resistance gene from the environment that is related to resistance genes in the medical settings. Since the knowledge of which way the resistance genes might move, from the natural environment to the human environment or vice versa, is not whole, I look in my research how wastewater treatment plants (WWTP) might influence the environments after purification. For this I measured quantitatively the copy numbers for several resistance genes in sewage and treated outgoing water and measured the differences between these two. The results showed that WWTP might not be a hot-spot for antibiotic resistance gene accumulation and increase.