Development of antibiotic resistance detection method for the express analysis of wastewater effluents
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Journal Title
Journal ISSN
Volume Title
Insinööritieteiden korkeakoulu |
Master's thesis
Authors
Date
2020-12-14
Department
Major/Subject
Mcode
Degree programme
Master's Programme in Water and Environmental Engineering (WAT)
Language
en
Pages
8+43+18
Series
Abstract
Antibiotic resistance is a well-known threat to global society that is becoming in-creasingly important. Due to the ubiquitous use of antibiotics for human, animal and agricultural purposes and their partial metabolic rate, these enter continually into wastewater treatment plants (WWTPs). Furthermore, the activated sludge pro-cess of wastewater treatment systems offers an optimal environment for resistance development and spread of antibiotic resistant genes (ARG) between bacteria. To better understand the occurrence of antibiotic resistant bacteria (ARB) in WWTP’s sludge and effluents, an easy, rapid and cheap testing method should be incorporate in WWTP’s analysis. So far, most of the studies on ARB in WWTPs have focused on a single antibiotic. Those conventional methods which only are able to test a single effect of antibiotic are not enough, because, the antibiotics never appear as a single compound, but rather as a complex mixture of antibiotics and chemicals. This leads to the devel-opment of multi-drug resistant bacteria (MDR). Thus, the method which is able to test the combination effect of antibiotics was selected in the literature research part. This thesis focuses on study of ARB in activated sludge. Four antibiotics and the mixture of them was studied: azithromycin (AZM), tetracycline (TCN), sulfameth-oxazole (SMX) and trimethoprim (TMP). Those four antibiotics are widely used in global level, and they can be found in wastewater treatment effluent. The antibiotic resistant detection method was tested and optimized. The method was based on agar dilution. Three different agar media and different antibiotic concentrations were tested. The results showed that in the range of 0,1mg/L to 4mg/L of studied antibiotics, the bacteria growth was significantly inhibited in higher antibiotic con-centration. However, high resistance was shown to SMX. In the medium with a mixture of antibiotics the results indicated a great synergy between them, and only few multi-drug resistant strains were detected. Among the three studied media, Mueller-Hinton agar allowed the higher growth of colonies and it was, thus, consid-ered the most suitable one. This research provides a preliminary protocol for the express analysis of antibiotic resistance in activated sludge and wastewater effluent studies.Description
Supervisor
Mikola, AnnaThesis advisor
Kruglova, AntoninaValtari, Maria
Keywords
activated sludge, antibiotic resistant bacteria, antibiotic resistant genes, multi-drug resistant, wastewater