scholarly journals Extracellular DNA (eDNA): Neglected and Potential Sources of Antibiotic Resistant Genes (ARGs) in the Aquatic Environments

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 874
Author(s):  
Periyasamy Sivalingam ◽  
John Poté ◽  
Kandasamy Prabakar
Keyword(s):  
Antibiotic Resistance ◽  
Health Risk ◽  
Genetic Material ◽  
Antibiotic Resistance Genes ◽  
Extracellular Dna ◽  
Antibiotic Resistant ◽  
Treatment Technologies ◽  
Environmental Bacteria ◽  
Global Threat ◽  
Potential Public Health

Over the past decades, the rising antibiotic resistance bacteria (ARB) are continuing to emerge as a global threat due to potential public health risk. Rapidly evolving antibiotic resistance and its persistence in the environment, have underpinned the need for more studies to identify the possible sources and limit the spread. In this context, not commonly studied and a neglected genetic material called extracellular DNA (eDNA) is gaining increased attention as it can be one of the significant drivers for transmission of extracellular ARGS (eARGs) via horizontal gene transfer (HGT) to competent environmental bacteria and diverse sources of antibiotic-resistance genes (ARGs) in the environment. Consequently, this review highlights the studies that address the environmental occurrence of eDNA and encoding eARGs and its impact on the environmental resistome. In this review, we also brief the recent dedicated technological advancements that are accelerating extraction of eDNA and the efficiency of treatment technologies in reducing eDNA that focuses on environmental antibiotic resistance and potential ecological health risk.

Horizontal transfer of antibiotic resistance genes in clinical environments

2019 ◽  
Vol 65 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Nicole A. Lerminiaux ◽  
Andrew D.S. Cameron
Keyword(s):  
Antibiotic Resistance ◽  
Antibiotic Resistance Gene ◽  
Genetic Material ◽  
Antibiotic Resistance Genes ◽  
Extracellular Dna ◽  
Genetic Diagnostics ◽  
Antibiotic Resistant ◽  
Rapid Spread ◽  
Medical Crisis ◽  
Clinical Environments

A global medical crisis is unfolding as antibiotics lose effectiveness against a growing number of bacterial pathogens. Horizontal gene transfer (HGT) contributes significantly to the rapid spread of resistance, yet the transmission dynamics of genes that confer antibiotic resistance are poorly understood. Multiple mechanisms of HGT liberate genes from normal vertical inheritance. Conjugation by plasmids, transduction by bacteriophages, and natural transformation by extracellular DNA each allow genetic material to jump between strains and species. Thus, HGT adds an important dimension to infectious disease whereby an antibiotic resistance gene (ARG) can be the agent of an outbreak by transferring resistance to multiple unrelated pathogens. Here, we review the small number of cases where HGT has been detected in clinical environments. We discuss differences and synergies between the spread of plasmid-borne and chromosomal ARGs, with a special consideration of the difficulties of detecting transduction and transformation by routine genetic diagnostics. We highlight how 11 of the top 12 priority antibiotic-resistant pathogens are known or predicted to be naturally transformable, raising the possibility that this mechanism of HGT makes significant contributions to the spread of ARGs. HGT drives the evolution of untreatable “superbugs” by concentrating ARGs together in the same cell, thus HGT must be included in strategies to prevent the emergence of resistant organisms in hospitals and other clinical settings.

scholarly journals A Mechanism of Unidirectional Transformation, Leading to Antibiotic Resistance, Occurs within Nasopharyngeal Pneumococcal Biofilm Consortia

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Santiago M. Lattar ◽  
Xueqing Wu ◽  
Jennifer Brophy ◽  
Fuminori Sakai ◽  
Keith P. Klugman ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Extracellular Dna ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Serotype Replacement ◽  
Genes Encoding ◽  
Receptor Cross Talk ◽  
Or Genes

ABSTRACT Streptococcus pneumoniae acquires genes for resistance to antibiotics such as streptomycin (Str) or trimethoprim (Tmp) by recombination via transformation of DNA released by other pneumococci and closely related species. Using naturally transformable pneumococci, including strain D39 serotype 2 (S2) and TIGR4 (S4), we studied whether pneumococcal nasopharyngeal transformation was symmetrical, asymmetrical, or unidirectional. Incubation of S2 Tet and S4 Str in a bioreactor simulating the human nasopharynx led to the generation of Spn Tet/Str recombinants. Double-resistant pneumococci emerged soon after 4 h postinoculation at a recombination frequency (rF) of 2.5 × 10 −4 while peaking after 8 h at a rF of 1.1 × 10 −3 . Acquisition of antibiotic resistance genes by transformation was confirmed by treatment with DNase I. A high-throughput serotyping method demonstrated that all double-resistant pneumococci belonged to one serotype lineage (S2 Tet/Str ) and therefore that unidirectional transformation had occurred. Neither heterolysis nor availability of DNA for transformation was a factor for unidirectional transformation given that the density of each strain and extracellular DNA (eDNA) released from both strains were similar. Unidirectional transformation occurred regardless of the antibiotic-resistant gene carried by donors or acquired by recipients and regardless of whether competence-stimulating peptide-receptor cross talk was allowed. Moreover, unidirectional transformation occurred when two donor strains (e.g., S4 Str and S19F Tmp ) were incubated together, leading to S19F Str/Tmp but at a rF 3 orders of magnitude lower (4.9 × 10 −6 ). We finally demonstrated that the mechanism leading to unidirectional transformation was due to inhibition of transformation of the donor by the recipient. IMPORTANCE Pneumococcal transformation in the human nasopharynx may lead to the acquisition of antibiotic resistance genes or genes encoding new capsular variants. Antibiotics and vaccines are currently putting pressure on a number of strains, leading to an increase in antibiotic resistance and serotype replacement. These pneumococcal strains are also acquiring virulence traits from vaccine types via transformation. In this study, we recapitulated multiple-strain colonization with strains carrying a resistance marker and selected for those acquiring resistance to two or three antibiotics, such as would occur in the human nasopharynx. Strains acquiring dual and triple resistance originated from one progenitor, demonstrating that transformation was unidirectional. Unidirectional transformation was the result of inhibition of transformation of donor strains. Unidirectional transformation has implications for the understanding of acquisition patterns of resistance determinants or capsule-switching events.

scholarly journals Mitigating Antibiotic Resistance Genes in Wastewater by Sequential Treatment with Novel Nanomaterials

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1593
Author(s):  
Lisa Paruch ◽  
Adam M. Paruch ◽  
Tanta-Verona Iordache ◽  
Andreea G. Olaru ◽  
Andrei Sarbu
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Bactericidal Effect ◽  
Resistant Bacteria ◽  
Emerging Pathogens ◽  
Antibiotic Resistant ◽  
Functionalized Nanomaterials ◽  
Treatment Technologies

Wastewater (WW) has been widely recognized as the major sink of a variety of emerging pathogens (EPs), antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs), which may disseminate and impact wider environments. Improving and maximizing WW treatment efficiency to remove these microbial hazards is fundamentally imperative. Despite a variety of physical, biological and chemical treatment technologies, the efficiency of ARG removal is still far from satisfactory. Within our recently accomplished M-ERA.NET project, novel functionalized nanomaterials, i.e., molecularly imprinted polymer (MIP) films and quaternary ammonium salt (QAS) modified kaolin microparticles, were developed and demonstrated to have significant EP removal effectiveness on both Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB) from WW. As a continuation of this project, we took the further step of exploring their ARG mitigation potential. Strikingly, by applying MIP and QAS functionalized kaolin microparticles in tandem, the ARGs prevalent in wastewater treatment plants (WWTPs), e.g., blaCTXM, ermB and qnrS, can be drastically reduced by 2.7, 3.9 and 4.9 log (copies/100 mL), respectively, whereas sul1, tetO and mecA can be eliminated below their detection limits. In terms of class I integron-integrase I (intI1), a mobile genetic element (MGE) for horizontal gene transfer (HGT), 4.3 log (copies/100 mL) reduction was achieved. Overall, the novel nanomaterials exhibit outstanding performance on attenuating ARGs in WW, being superior to their control references. This finding provides additional merit to the application of developed nanomaterials for WW purification towards ARG elimination, in addition to the proven bactericidal effect.

scholarly journals Inactivation of antibiotic-resistant bacteria and antibiotic resistance genes by electrochemical oxidation/electro-Fenton process

2020 ◽  
Vol 81 (10) ◽  
pp. 2221-2231 ◽  
Author(s):  
Lei Chen ◽  
Zhi Zhou ◽  
Chaofeng Shen ◽  
Yilu Xu
Keyword(s):  
Antibiotic Resistance ◽  
Electrochemical Oxidation ◽  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Fenton Process ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Treatment Technologies

Abstract Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in the environment are of great concern due to their potential risk to human health. The effluents from wastewater treatment plants and livestock production are major sources of ARB and ARGs. Chlorination, UV irradiation, and ozone disinfection cannot remove ARGs completely. In this study, the potential of electrochemical oxidation and electro-Fenton processes as alternative treatment technologies for inactivation of ARB and ARGs in both intracellular and extracellular forms was evaluated. Results showed that the electrochemical oxidation process was effective for the inactivation of selected ARB but not for the removal of intracellular ARGs or extracellular ARGs. The electro-Fenton process was more effective for the removal of both intracellular and extracellular ARGs. The removal efficiency after 120 min of electro-Fenton treatment under 21.42 mA/cm2 was 3.8 logs for intracellular tetA, 4.1 logs for intracellular ampC, 5.2 logs for extracellular tetA, and 4.8 logs for extracellular ampC, respectively in the presence of 1.0 mmol/L Fe2+. It is suggested that electrochemical oxidation is an effective disinfection method for ARB and the electro-Fenton process is a promising technology for the removal of both intracellular and extracellular ARGs in wastewater.

scholarly journals Treatment Processes for Microbial Resistance Mitigation: The Technological Contribution to Tackle the Problem of Antibiotic Resistance

2020 ◽  
Vol 17 (23) ◽  
pp. 8866
Author(s):  
Gabriela Bairán ◽  
Georgette Rebollar-Pérez ◽  
Edith Chávez-Bravo ◽  
Eduardo Torres
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Treatment Processes ◽  
Treatment Technologies ◽  
High Doses

Advances generated in medicine, science, and technology have contributed to a better quality of life in recent years; however, antimicrobial resistance has also benefited from these advances, creating various environmental and health problems. Several determinants may explain the problem of antimicrobial resistance, such as wastewater treatment plants that represent a powerful agent for the promotion of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARG), and are an important factor in mitigating the problem. This article focuses on reviewing current technologies for ARB and ARG removal treatments, which include disinfection, constructed wetlands, advanced oxidation processes (AOP), anaerobic, aerobic, or combined treatments, and nanomaterial-based treatments. Some of these technologies are highly intensive, such as AOP; however, other technologies require long treatment times or high doses of oxidizing agents. From this review, it can be concluded that treatment technologies must be significantly enhanced before the environmental and heath problems associated with antimicrobial resistance can be effectively solved. In either case, it is necessary to achieve total removal of bacteria and genes to avoid the possibility of regrowth given by the favorable environmental conditions at treatment plant facilities.

scholarly journals Antibiotic Resistance in Wastewater and Its Impact on a Receiving River: A Case Study of WWTP Brno-Modřice, Czech Republic

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2309
Author(s):  
Iva Buriánková ◽  
Peter Kuchta ◽  
Anna Molíková ◽  
Kateřina Sovová ◽  
David Výravský ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Water Environment ◽  
Antibiotic Resistance Genes ◽  
Treated Wastewater ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Receiving River ◽  
Global Threat

Antibiotic resistance has become a global threat in which the anthropogenically influenced aquatic environment represents not only a reservoir for the spread of antibiotic resistant bacteria (ARB) among humans and animals but also an environment where resistance genes are introduced into natural microbial ecosystems. Wastewater is one of the sources of antibiotic resistance. The aim of this research was the evaluation of wastewater impact on the spread of antibiotic resistance in the water environment. In this study, qPCR was used to detect antibiotic resistance genes (ARGs)—blaCTX-M-15, blaCTX-M-32, ampC, blaTEM, sul1, tetM and mcr-1 and an integron detection primer (intl1). Detection of antibiotic resistant Escherichia coli was used as a complement to the observed qPCR results. Our results show that the process of wastewater treatment significantly reduces the abundances of ARGs and ARB. Nevertheless, treated wastewater affects the ARGs and ARB number in the receiving river.

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