Research highlights: antibiotic resistance genes: from wastewater into the environment

2015 ◽  
Vol 1 (3) ◽  
pp. 264-267 ◽  
Author(s):  
David T. Tan ◽  
Danmeng Shuai
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Natural Transformation ◽  
Antibiotic Resistance Genes ◽  
Quantitative Model ◽  
Land Application ◽  
Untreated Wastewater

We highlight the effects of treated and untreated wastewater on antibiotic resistance genes (ARGs) in the environment, attenuation of ARGs following land application of wastewater solids, and a quantitative model for natural transformation.

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.

Fate and Transport of Antibiotic Residues and Antibiotic Resistance Genes following Land Application of Manure Waste

2009 ◽  
Vol 38 (3) ◽  
pp. 1086-1108 ◽  
Author(s):  
Joanne C. Chee-Sanford ◽  
Roderick I. Mackie ◽  
Satoshi Koike ◽  
Ivan G. Krapac ◽  
Yu-Feng Lin ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Fate And Transport ◽  
Land Application ◽  
Antibiotic Residues

scholarly journals Metagenomic Analysis of Antibiotic Resistance Genes in Untreated Wastewater From Three Different Hospitals

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiurong Guo ◽  
Nan Tang ◽  
Hui Lei ◽  
Qi Fang ◽  
Li Liu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
High Throughput Sequencing ◽  
Antibiotic Resistance Genes ◽  
Pollution Source ◽  
Resistant Bacteria ◽  
Hospital Wastewater ◽  
Protection Measures ◽  
Untreated Wastewater ◽  
Different Types

Controlling antibiotic resistance genes (ARGs) is a worldwide intervention to ensure global health. Hospital wastewater is the main pollution source of antibiotic-resistant bacteria and ARGs in the environment. Expanding our knowledge on the bacterial composition of hospital wastewater could help us to control infections in hospitals and decrease pathogen release into the environment. In this study, a high-throughput sequencing-based metagenomic approach was applied to investigate the community composition of bacteria and ARGs in untreated wastewater from three different types of hospitals [the general hospital, traditional Chinese medicine (TCM) hospital, and stomatology hospital]. In total, 130 phyla and 2,554 genera were identified from the microbiota of the wastewaters, with significantly different bacterial community compositions among the three hospitals. Total ARG analysis using the Antibiotic Resistance Genes Database (ARDB) and Comprehensive Antibiotic Resistance Database (CARD) revealed that the microbiota in the wastewaters from the three hospitals harbored different types and percentage of ARGs, and their composition was specific to the hospital type based on the correlation analysis between species and ARG abundance, some ARGs contributed to different bacterial genera with various relationships in different hospitals. In summary, our findings demonstrated a widespread occurrence of ARGs and ARG-harboring microbiota in untreated wastewaters of different hospitals, suggesting that protection measures should be applied to prevent human infections. Concurrently, hospital wastewater should be treated more specifically for the removal of pathogens before its discharge into the urban sewage system.

scholarly journals Horizontal gene transfer facilitates the spread of extracellular antibiotic resistance genes in soil

2021 ◽  
Author(s):  
Heather A. Kittredge ◽  
Kevin M. Dougherty ◽  
Sarah E. Evans
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Resistance Genes ◽  
Natural Transformation ◽  
Antibiotic Resistance Genes ◽  
Live Cells ◽  
Resistant Bacteria ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant

AbstractAntibiotic resistance genes (ARGs) are ubiquitous in the environment and pose a serious risk to human and veterinary health. While many studies focus on the spread of live antibiotic resistant bacteria throughout the environment, it is unclear whether extracellular ARGs from dead cells can transfer to live bacteria to facilitate the evolution of antibiotic resistance in nature. Here, we inoculate antibiotic-free soil with extracellular ARGs (eARGs) from dead Pseudeononas stutzeri cells and track the evolution of antibiotic resistance via natural transformation – a mechanism of horizontal gene transfer involving the genomic integration of eARGs. We find that transformation facilitates the rapid evolution of antibiotic resistance even when eARGs occur at low concentrations (0.25 μg g-1 soil). However, when eARGs are abundant, transformation increases substantially. The evolution of antibiotic resistance was high under soil moistures typical in terrestrial systems (5%-30% gravimetric water content) and was only inhibited at very high soil moistures (>30%). While eARGs transformed into live cells at a low frequency, exposure to a low dose of antibiotic allowed a small number of transformants to reach high abundances in laboratory populations, suggesting even rare transformation events pose a risk to human health. Overall, this work demonstrates that dead bacteria and their eARGs are an overlooked path to antibiotic resistance, and that disinfection alone is insufficient to stop the spread of antibiotic resistance. More generally, the spread of eARGs in antibiotic-free soil suggests that transformation allows genetic variants to establish at low frequencies in the absence of antibiotic selection.ImportanceOver the last decade, antibiotics in the environment have gained increasing attention because they can select for drug-resistant phenotypes that would have otherwise gone extinct. To counter this effect, bacterial populations exposed to antibiotics often undergo disinfection. However, the release of extracellular antibiotic resistance genes (eARGs) into the environment following disinfection can promote the transfer of eARGs through natural transformation. This phenomenon is well-documented in wastewater and drinking water, but yet to be investigated in soil. Our results directly demonstrate that eARGs from dead bacteria are an important, but often overlooked source of antibiotic resistance in soil. We conclude that disinfection alone is insufficient to prevent the spread of ARGs. Special caution should be taken in releasing antibiotics into the environment, even if there are no live antibiotic resistant bacteria in the community, as transformation allows DNA to maintain its biological activity past microbial death.

scholarly journals Chlorine disinfection facilitates natural transformation through ROS-mediated oxidative stress

2021 ◽  
Author(s):  
Shuai Zhang ◽  
Yue Wang ◽  
Ji Lu ◽  
Zhigang Yu ◽  
Hailiang Song ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Natural Transformation ◽  
Membrane Damage ◽  
Antibiotic Resistance Genes ◽  
Free Chlorine ◽  
Water Disinfection ◽  
Resistant Bacteria ◽  
Residual Chlorine ◽  
Acinetobacter Baylyi

AbstractThe bacterial infection that involves antimicrobial resistance is a rising global threat to public health. Chlorine-based water disinfection processes can inactivate antibiotic resistant bacteria. However, at the same time, these processes may cause the release of antibiotic resistance genes into the water as free DNA, and consequently increase the risk to disseminate antibiotic resistance via natural transformation. Presently, little is known about the contribution of residual chlorine affecting the transformation of extracellular antibiotic resistance genes (ARGs). This study investigates whether chloramine and free chlorine promote the transformation of ARGs and how this may occur. We reveal that both chloramine and free chlorine, at practically relevant concentrations, significantly stimulated the transformation of plasmid-encoded ARGs by the recipient Acinetobacter baylyi ADP1, by up to a 10-fold increase. The underlying mechanisms underpinning the increased transformations were revealed. Disinfectant exposure induced a series of cell responses, including increased levels of reactive oxygen species (ROS), bacterial membrane damage, ROS-mediated DNA damage, and increased stress response. These effects thus culminated in the enhanced transformation of ARGs. This promoted transformation was observed when exposing disinfectant-pretreated A. baylyi to free plasmid. In contrast, after pretreating free plasmid with disinfectants, the transformation of ARGs decreased due to the damage of plasmid integrity. These findings provide important insight on the roles of disinfectants affecting the horizontal transfer of ARGs, which could be crucial in the management of antibiotic resistance in our water systems.

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 Artificial sweeteners stimulate horizontal transfer of extracellular antibiotic resistance genes through natural transformation

2021 ◽  
Author(s):  
Zhigang Yu ◽  
Yue Wang ◽  
Ian R. Henderson ◽  
Jianhua Guo
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Horizontal Transfer ◽  
Natural Transformation ◽  
Model Organism ◽  
Antibiotic Resistance Genes ◽  
Artificial Sweeteners ◽  
Dna Uptake ◽  
Long Term Effects ◽  
Acinetobacter Baylyi

AbstractAntimicrobial resistance has emerged as a global threat to human health. Natural transformation is an important pathway for horizontal gene transfer, which facilitates the dissemination of antibiotic resistance genes (ARGs) among bacteria. Although it is suspected that artificial sweeteners could exert antimicrobial effects, little is known whether artificial sweeteners would also affect horizontal transfer of ARGs via transformation. Here we demonstrate that four commonly used artificial sweeteners (saccharin, sucralose, aspartame, and acesulfame potassium) promote transfer of ARGs via natural transformation in Acinetobacter baylyi ADP1, a model organism for studying competence and transformation. Such phenomenon was also found in a Gram-positive human pathogen Bacillus subtilis and mice faecal microbiome. We reveal that exposure to these sweeteners increases cell envelope permeability and results in an upregulation of genes encoding DNA uptake and translocation (Com) machinery. In addition, we find that artificial sweeteners induce an increase in plasmid persistence in transformants. We propose a mathematical model established to predict the long-term effects on transformation dynamics under exposure to these sweeteners. Collectively, our findings offer insights into natural transformation promoted by artificial sweeteners and highlight the need to evaluate these environmental contaminants for their antibiotic-like side effects.

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