scholarly journals The occurrence of specific markers of Bacteroides fragilis group, B. dorei and antibiotic-resistance genes in the wastewater treatment plants

2018 ◽  
Vol 44 ◽  
pp. 00124
Author(s):  
Sebastian Niestępski ◽  
Monika Harnisz ◽  
Ewa Korzeniewska ◽  
Adriana Osińska

Wastewater treatment plants (WWTPs) are one of the main transmission sources of pathogenic bacteria and antibiotic-resistance genes in the natural environment. In this study, the presence of specific markers of Bacteroides fragilis group (BFG), B. dorei and genes encoding resistance to beta-lactams (cepA, cfxA), tetracyclines (tet(Q)), macrolides, lincosamides and streptogramins (MLS) mechanism (ermF, linA) was analyzed by standard PCR in the inflows and outflows from three wastewater treatment plants with the activated sludge process. Genetic material was isolated from wastewater samples with the use of two commercial kits for genomic DNA extraction, the Fast DNA SPIN Kit for Soil and the Genomic Micro AX Bacteria Gravity Kit. The quality of the isolated genetic material differed between the tested isolation kits. The Fast DNA SPIN Kit for Soil was more effective in detecting cfxA, ermF and linA genes. However, both extraction kits effectively identified tet(Q), bfr and HF183/BacR287 genes in all wastewater samples. The results of the study indicate that genes specific to BFG and B. dorei, and genes encoding resistance to MLS and tetracyclines are not completely eliminated during the wastewater treatment process.

2020 ◽  
Vol 10 (17) ◽  
pp. 5816
Author(s):  
Damian Rolbiecki ◽  
Monika Harnisz ◽  
Ewa Korzeniewska ◽  
Łukasz Jałowiecki ◽  
Grażyna Płaza

This study identified differences in the prevalence of antibiotic resistance genes (ARGs) between wastewater treatment plants (WWTPs) processing different proportions of hospital and municipal wastewater as well as various types of industrial wastewater. The influence of treated effluents discharged from WWTPs on the receiving water bodies (rivers) was examined. Genomic DNA was isolated from environmental samples (river water, wastewater and sewage sludge). The presence of genes encoding resistance to sulfonamides (sul1, sul2) and fluoroquinolones (qepA, aac(6′)-Ib-cr) was determined by standard polymerase chain reaction (PCR). The effect of the sampling season (summer – June, fall – November) was analyzed. Treated wastewater and sewage sludge were significant reservoirs of antibiotic resistance and contained all of the examined ARGs. All wastewater samples contained sul1 and aac(6′)-lb-cr genes, while the qepA and sul2 genes occurred less frequently. These observations suggest that the prevalence of ARGs is determined by the type of processed wastewater. The Warmia and Mazury WWTP was characterized by higher levels of the sul2 gene, which could be attributed to the fact that this WWTP processes agricultural sewage containing animal waste. However, hospital wastewater appears to be the main source of the sul1 gene. The results of this study indicate that WWTPs are significant sources of ARGs, contributing to the spread of antibiotic resistance in rivers receiving processed wastewater.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 650 ◽  
Author(s):  
Ioanna Zerva ◽  
Ioanna Alexandropoulou ◽  
Maria Panopoulou ◽  
Paraschos Melidis ◽  
Spyridon Ntougias

Wastewater treatment plants (WWTPs) highly contribute to the transmission of antibiotic resistance genes (ARGs) in the environment. In this work, the diversity of ermF, ermB, sul1 and int1-enconding genes was examined in the influent, the mixed liquor and the effluent of a full-scale WWTP. Based on the clones analyzed, similar genotypes were recorded at all process stages. However, distinct genotypes of int1 were responsible for the expression of sul1 and ermF genes in Gammaproteobacteria and Bacteroidetes, respectively. Due to the detection of similar ARGs profiles throughout the biological process, it is concluded that additional treatment is needed for their retention.


Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1516
Author(s):  
Il Han ◽  
Keunje Yoo

Wastewater treatment plants (WWTPs) have been considered hotspots for the development and dissemination of antibiotic resistance in the environment. Although researchers have reported a significant increase in bioaerosols in WWTPs, the associated bacterial taxa, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) remain relatively unknown. In this study, we have investigated the abundance and occurrences of ARGs and MGEs, as well as the bacterial community compositions in activated sludge (AS), dewatered sludge (DS) and bioaerosols (BA) in a WWTP. In total, 153 ARG subtypes belonging to 19 ARG types were identified by the broad scanning of metagenomic profiles obtained using Illumina HiSeq. The results indicated that the total occurrences and abundances of ARGs in AS and DS samples were significantly higher than those in BA samples (p < 0.05). However, some specific ARG types related to sulfonamide, tetracycline, macrolide resistance were present in relatively high abundance in BA samples. Similar to many other full-scale WWTPs, the Proteobacteria (58%) and Bacteroidetes (18%) phyla were dominant in the AS and DS samples, while the Firmicutes (25%) and Actinobacteria (20%) phyla were the most dominant in the BA samples. Although the abundance of genes related to plasmids and integrons in bioaerosols were two to five times less than those in AS and DS samples, different types of MGEs were observed in BA samples. These results suggest that comprehensive analyses of resistomes in BA are required to better understand the emergence of both ARGs and MGEs in the wastewater treatment process due to the significant increase of scientific attention toward bioaerosols effects.


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