scholarly journals Is sewage sludge a valuable fertilizer? A soil microbiome and resistome study under field conditions

2021 ◽  
Author(s):  
Anna Markowicz ◽  
Kinga Bondarczuk ◽  
Aleksandra Wiekiera ◽  
Sławomir Sułowicz
Keyword(s):  
Antibiotic Resistance ◽  
Sewage Sludge ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Nutrient Content ◽  
Metal Resistance ◽  
Land Application ◽  
Soil Microbiome ◽  
Soil Microbial ◽  
Cu Content

Abstract Purpose Sewage sludge land application is strongly recommended to improve soil quality and fertility despite the presence of pollutants, pathogens and antibiotic resistance genes. This study aimed to assess the fertilization value of low and recommended by law sewage sludge dose (15 t ha−1). Materials and methods In a 540-day field study, the effect of sewage sludge on the soil physicochemical and microbial parameters, emphasising antibiotic and metal resistance spread, was investigated. Results In contrast to expectations, sewage sludge did not improve the organic matter, nutrient content and microbial activity in the soil; therefore, the fertilization effect was not achieved. Moreover, an increase in the bioavailable Cd, Ni and Cu content was observed. Canonical correspondence analysis revealed that these increases mainly explain the changes in the soil microbial community. Sixteen resistance genes and four integron classes were detected in both the total DNA and on plasmids isolated from sewage sludge. Obtained plasmids confer β-lactam resistance or extreme resistance to tetracycline (> 256 μg mL−1). Two antibiotic resistance genes (blaNPS-2, tetA) were transferred into the fertilized soil and detected up to 6 months after the fertilization. Conclusion Our results provide evidence that the regulated dose of sewage sludge, even when characterized by low total metal content, may affect soil microbial microbiome and resistome. Therefore, these findings provide critical data that have public health implications, which may raise concerns about the suitability of applying sewage sludge to the soil even at the low regulated dose.

scholarly journals Combined effects of composting and antibiotic administration on cattle manure–borne antibiotic resistance genes

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Ishi Keenum ◽  
Robert K. Williams ◽  
Partha Ray ◽  
Emily D. Garner ◽  
Katharine F. Knowlton ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Land Application ◽  
Multidimensional Analysis ◽  
Small Scale ◽  
Antibiotic Administration ◽  
Metagenomic Sequencing ◽  
Combined Effects ◽  
Bacterial Microbiota

Abstract Background Research is needed to delineate the relative and combined effects of different antibiotic administration and manure management practices in either amplifying or attenuating the potential for antibiotic resistance to spread. Here, we carried out a comprehensive parallel examination of the effects of small-scale (> 55 °C × 3 days) static and turned composting of manures from dairy and beef cattle collected during standard antibiotic administration (cephapirin/pirlimycin or sulfamethazine/chlortetracycline/tylosin, respectively), versus from untreated cattle, on “resistomes” (total antibiotic resistance genes (ARGs) determined via shotgun metagenomic sequencing), bacterial microbiota, and indicator ARGs enumerated via quantitative polymerase chain reaction. To gain insight into the role of the thermophilic phase, compost was also externally heated to > 55 °C × 15 days. Results Progression of composting with time and succession of the corresponding bacterial microbiota was the overarching driver of the resistome composition (ANOSIM; R = 0.424, p = 0.001, respectively) in all composts at the small-scale. Reduction in relative abundance (16S rRNA gene normalized) of total ARGs in finished compost (day 42) versus day 0 was noted across all conditions (ANOSIM; R = 0.728, p = 0.001), except when externally heated. Sul1, intI1, beta-lactam ARGs, and plasmid-associated genes increased in all finished composts as compared with the initial condition. External heating more effectively reduced certain clinically relevant ARGs (blaOXA, blaCARB), fecal coliforms, and resistome risk scores, which take into account putative pathogen annotations. When manure was collected during antibiotic administration, taxonomic composition of the compost was distinct according to nonmetric multidimensional analysis and tet(W) decayed faster in the dairy manure with antibiotic condition and slower in the beef manure with antibiotic condition. Conclusions This comprehensive, integrated study revealed that composting had a dominant effect on corresponding resistome composition, while little difference was noted as a function of collecting manure during antibiotic administration. Reduction in total ARGs, tet(W), and resistome risk suggested that composting reduced some potential for antibiotic resistance to spread, but the increase and persistence of other indicators of antibiotic resistance were concerning. Results indicate that composting guidelines intended for pathogen reduction do not necessarily provide a comprehensive barrier to ARGs or their mobility prior to land application and additional mitigation measures should be considered.

Rare earth oxide nanoparticles promote soil microbial antibiotic resistance by selectively enriching antibiotic resistance genes

2019 ◽  
Vol 6 (2) ◽  
pp. 456-466 ◽  
Author(s):  
Lin Qi ◽  
Yuan Ge ◽  
Tian Xia ◽  
Ji-Zheng He ◽  
Congcong Shen ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Rare Earth ◽  
Microbial Communities ◽  
Resistance Genes ◽  
Soil Microbial Communities ◽  
Antibiotic Resistance Genes ◽  
Rare Earth Oxide ◽  
Oxide Nanoparticles ◽  
Soil Microbial

This study demonstrates that rare earth oxide nanoparticles can enhance soil microbial antibiotic resistance by inducing the enrichment and spread of antibiotic resistance genes in soil microbial communities.

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