scholarly journals Fate of antibiotic resistant E. coli and antibiotic resistance genes during full scale conventional and advanced anaerobic digestion of sewage sludge

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0237283
Author(s):  
Sky Redhead ◽  
Jeroen Nieuwland ◽  
Sandra Esteves ◽  
Do-Hoon Lee ◽  
Dae-Wi Kim ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Relative Abundance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Absolute Abundance ◽  
Sludge Treatment ◽  
Antibiotic Resistant ◽  
Pre Treatment

Antibiotic resistant bacteria (ARB) and their genes (ARGs) have become recognised as significant emerging environmental pollutants. ARB and ARGs in sewage sludge can be transmitted back to humans via the food chain when sludge is recycled to agricultural land, making sludge treatment key to control the release of ARB and ARGs to the environment. This study investigated the fate of antibiotic resistant Escherichia coli and a large set of antibiotic resistance genes (ARGs) during full scale anaerobic digestion (AD) of sewage sludge at two U.K. wastewater treatment plants and evaluated the impact of thermal hydrolysis (TH) pre-treatment on their abundance and diversity. Absolute abundance of 13 ARGs and the Class I integron gene intI1 was calculated using single gene quantitative (q) PCR. High through-put qPCR analysis was also used to determine the relative abundance of 370 ARGs and mobile genetic elements (MGEs). Results revealed that TH reduced the absolute abundance of all ARGs tested and intI1 by 10–12,000 fold. After subsequent AD, a rebound effect was seen in many ARGs. The fate of ARGs during AD without pre-treatment was variable. Relative abundance of most ARGs and MGEs decreased or fluctuated, with the exception of macrolide resistance genes, which were enriched at both plants, and tetracyline and glycopeptide resistance genes which were enriched in the plant employing TH. Diversity of ARGs and MGEs decreased in both plants during sludge treatment. Principal coordinates analysis revealed that ARGs are clearly distinguished according to treatment step, whereas MGEs in digested sludge cluster according to site. This study provides a comprehensive within-digestor analysis of the fate of ARGs, MGEs and antibiotic resistant E. coli and highlights the effectiveness of AD, particularly when TH is used as a pre-treatment, at reducing the abundance of most ARGs and MGEs in sludgeand preventing their release into the environment.

scholarly journals Study of Occurrence Characteristics of Antibiotic Resistance Genes in Pig manure during Anaerobic Digestion and Digestate Fertilization

2021 ◽  
Vol 233 ◽  
pp. 01130
Author(s):  
PAN Xin-rong ◽  
CHEN Lei ◽  
YU Heng ◽  
ZUO Jian-e
Keyword(s):  
Antibiotic Resistance ◽  
Anaerobic Digestion ◽  
Relative Abundance ◽  
Resistance Genes ◽  
Poultry Manure ◽  
Antibiotic Resistance Genes ◽  
Pig Manure ◽  
Rrna Gene ◽  
Occurrence Characteristics ◽  
Biogas Residue

Antibiotic resistance genes (ARGs) existing in livestock and poultry manure have the risk to spread and proliferate. This might endanger people’s health. The common treatment of livestock and poultry manure is anaerobic digestion. But the change of ARGs during anaerobic digestion require further study, and the effect of digestate fertilization to the antibiotic resistance of cropland soil is still unclear. This study investigated the pig manure, biogas liquid, biogas residue, and cropland soils fertilized with and without digestate. The results showed that, the relative abundance of ARGs in biogas residue was much higher than other samples. The average relative abundance was 1.46×10-1 copy ratio (copy of ARG/copy of 16S rRNA gene), and the total relative abundance was 3.07 copy ratio. There were 21 ARGs detected in the 5 samples. 11 of them were shared by the 5 samples. The main ARGs were aminoglycoside, chloramphenicol, sulfonamide, tetracycline, and multidrug. Aminoglycoside had the highest relative abundance, and the total relative abundance in all samples was 1.18 copy ratio. Anaerobic digestion increased the total relative abundance of ARGs in pig manure from 1.14×10-1 to 1.70×10-1 copy ratio. Fertilization of digestate increased the total relative abundance of AGRs in soil from 3.27×10-1 to 7.29×10-1 copy ratio.

scholarly journals Impact of Fertilizing with Raw or Anaerobically Digested Sewage Sludge on the Abundance of Antibiotic-Resistant Coliforms, Antibiotic Resistance Genes, and Pathogenic Bacteria in Soil and on Vegetables at Harvest

2014 ◽  
Vol 80 (22) ◽  
pp. 6898-6907 ◽  
Author(s):  
Teddie O. Rahube ◽  
Romain Marti ◽  
Andrew Scott ◽  
Yuan-Ching Tien ◽  
Roger Murray ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Sewage Sludge ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Antibiotic Resistance Genes ◽  
Coliform Bacteria ◽  
Agricultural Practice ◽  
Antibiotic Resistant ◽  
Human Waste ◽  
Class B

ABSTRACTThe consumption of crops fertilized with human waste represents a potential route of exposure to antibiotic-resistant fecal bacteria. The present study evaluated the abundance of bacteria and antibiotic resistance genes by using both culture-dependent and molecular methods. Various vegetables (lettuce, carrots, radish, and tomatoes) were sown into field plots fertilized inorganically or with class B biosolids or untreated municipal sewage sludge and harvested when of marketable quality. Analysis of viable pathogenic bacteria or antibiotic-resistant coliform bacteria by plate counts did not reveal significant treatment effects of fertilization with class B biosolids or untreated sewage sludge on the vegetables. Numerous targeted genes associated with antibiotic resistance and mobile genetic elements were detected by PCR in soil and on vegetables at harvest from plots that received no organic amendment. However, in the season of application, vegetables harvested from plots treated with either material carried gene targets not detected in the absence of amendment. Several gene targets evaluated by using quantitative PCR (qPCR) were considerably more abundant on vegetables harvested from sewage sludge-treated plots than on vegetables from control plots in the season of application, whereas vegetables harvested the following year revealed no treatment effect. Overall, the results of the present study suggest that producing vegetable crops in ground fertilized with human waste without appropriate delay or pretreatment will result in an additional burden of antibiotic resistance genes on harvested crops. Managing human exposure to antibiotic resistance genes carried in human waste must be undertaken through judicious agricultural practice.

scholarly journals Impact of Long-Term Manure and Sewage Sludge Application to Soil as Organic Fertilizer on the Incidence of Pathogenic Microorganisms and Antibiotic Resistance Genes

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1423
Author(s):  
Hana Stiborova ◽  
Martina Kracmarova ◽  
Tereza Vesela ◽  
Marta Biesiekierska ◽  
Jindrich Cerny ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Sewage Sludge ◽  
Relative Abundance ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Agricultural Soils ◽  
Organic Fertilizer ◽  
Antibiotic Resistance Genes ◽  
Thermophilic Conditions ◽  
Repeated Applications

The reuse of stabilized (under thermophilic conditions) sewage sludge and manure on agricultural soils is a common practice. The aim of this study was to evaluate the risks associated with their repeated applications on the spread of pathogenic bacteria and antibiotic resistance genes (ARGs) that encode resistance to tetracycline (tetA and tetW), sulphonamide (sul1 and sul2), erythromycin (ermB), vancomycin (vanA) and integron genetic element (intI1). The trial fields has been regularly fertilized every 3rd year since 1996 with manure (MF; 330 kg N/ha) and sewage sludge (SF; 330 kg N/ha and SF3; 990 kg N/ha). Unfertilized soil (CF) served as a control. Samples were collected at different time points: (i) right before fertilization (which was also 3 years after the last fertilization), (ii) 5 months after fertilization, and (iii) 11 months after fertilization. The relative abundance of amplicon sequence variants (ASVs) assigned to potentially pathogenic bacteria was low (0.3% and 0.25% in sludge and manure, respectively), and no association with the application of these fertilizers was found. On the other hand, our data indicate that an increased relative abundance of the ARGs sul1 and tetW was significantly associated with these fertilizer applications, and sul1 was increased in all treatments regardless of the time. It is suggested that sul1 should be monitored in organically fertilized soils to prevent its spread and possible further accumulation in crops.

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