scholarly journals Quantitative PCR Monitoring of Antibiotic Resistance Genes and Bacterial Pathogens in Three European Artificial Groundwater Recharge Systems

2008 ◽  
Vol 75 (1) ◽  
pp. 154-163 ◽  
Author(s):  
Uta B�ckelmann ◽  
Hans-Henno D�rries ◽  
M. Neus Ayuso-Gabella ◽  
Miquel Salgot de Mar�ay ◽  
Valter Tandoi ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Groundwater Recharge ◽  
Quantitative Pcr ◽  
Resistance Genes ◽  
Bacterial Pathogens ◽  
Reclaimed Water ◽  
Antibiotic Resistance Genes ◽  
Aquifer Recharge ◽  
Human Pathogens ◽  
Integrated Water Management

ABSTRACT Aquifer recharge presents advantages for integrated water management in the anthropic cycle, namely, advanced treatment of reclaimed water and additional dilution of pollutants due to mixing with natural groundwater. Nevertheless, this practice represents a health and environmental hazard because of the presence of pathogenic microorganisms and chemical contaminants. To assess the quality of water extracted from recharged aquifers, the groundwater recharge systems in Torreele, Belgium, Sabadell, Spain, and Nard�, Italy, were investigated for fecal-contamination indicators, bacterial pathogens, and antibiotic resistance genes over the period of 1 year. Real-time quantitative PCR assays for Helicobacter pylori, Yersinia enterocolitica, and Mycobacterium avium subsp. paratuberculosis, human pathogens with long-time survival capacity in water, and for the resistance genes ermB, mecA, blaSHV-5, ampC, tetO, and vanA were adapted or developed for water samples differing in pollutant content. The resistance genes and pathogen concentrations were determined at five or six sampling points for each recharge system. In drinking and irrigation water, none of the pathogens were detected. tetO and ermB were found frequently in reclaimed water from Sabadell and Nard�. mecA was detected only once in reclaimed water from Sabadell. The three aquifer recharge systems demonstrated different capacities for removal of fecal contaminators and antibiotic resistance genes. Ultrafiltration and reverse osmosis in the Torreele plant proved to be very efficient barriers for the elimination of both contaminant types, whereas aquifer passage followed by UV treatment and chlorination at Sabadell and the fractured and permeable aquifer at Nard� posed only partial barriers for bacterial contaminants.

scholarly journals The resistome of common human pathogens

2017 ◽  
Author(s):  
Christian Munck ◽  
Mostafa M. Hashim Ellabaan ◽  
Michael Schantz Klausen ◽  
Morten O.A. Sommer
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Bacterial Pathogens ◽  
Antibiotic Resistance Genes ◽  
Gene Clusters ◽  
Species Level ◽  
Natural Environments ◽  
Human Pathogens ◽  
Bacterial Genomes ◽  
Risk Ranking

AbstractGenes capable of conferring resistance to clinically used antibiotics have been found in many different natural environments. However, a concise overview of the resistance genes found in common human bacterial pathogens is lacking, which complicates risk ranking of environmental reservoirs. Here, we present an analysis of potential antibiotic resistance genes in the 17 most common bacterial pathogens isolated from humans. We analyzed more than 20,000 bacterial genomes and defined a clinical resistome as the set of resistance genes found across these genomes. Using this database, we uncovered the co-occurrence frequencies of the resistance gene clusters within each species enabling identification of co-dissemination and co-selection patterns. The resistance genes identified in this study represent the subset of the environmental resistome that is clinically relevant and the dataset and approach provides a baseline for further investigations into the abundance of clinically relevant resistance genes across different environments. To facilitate an easy overview the data is presented at the species level at www.resistome.biosustain.dtu.dk.

scholarly journals Coexistence of Antibiotic Resistance Genes and Virulence Factors Deciphered by Large-Scale Complete Genome Analysis

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Yu Pan ◽  
Jiaxiong Zeng ◽  
Liguan Li ◽  
Jintao Yang ◽  
Ziyun Tang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Large Scale ◽  
Antibiotic Resistance Genes ◽  
Comprehensive Analysis ◽  
Health Concern ◽  
Human Pathogens ◽  
Bacterial Genomes ◽  
Gene Acquisition

ABSTRACT Widespread use of antibiotics has enhanced the evolution of highly resilient pathogens and poses a severe risk to human health via coselection of antibiotic resistance genes (ARGs) and virulence factors (VFs). In this study, we rigorously evaluate the abundance relationship and physical linkage between ARGs and VFs by performing a comprehensive analysis of 9,070 bacterial genomes isolated from multiple species and hosts. The coexistence of ARGs and VFs was observed in bacteria across distinct phyla, pathogenicities, and habitats, especially among human-associated pathogens. The coexistence patterns of gene elements in different habitats and pathogenicity groups were similar, presumably due to frequent gene transfer. A shorter intergenic distance between mobile genetic elements and ARGs/VFs was detected in human/animal-associated bacteria, indicating a higher transfer potential. Increased accumulation of exogenous ARGs/VFs in human pathogens highlights the importance of gene acquisition in the evolution of human commensal bacteria. Overall, the findings provide insights into the genic features of combinations of ARG-VF and expand our understanding of ARG-VF coexistence in bacteria. IMPORTANCE Antibiotic resistance has become a serious global health concern. Despite numerous case studies, a comprehensive analysis of ARG and VF coexistence in bacteria is lacking. In this study, we explore the coexistence profiles of ARGs and VFs in diverse categories of bacteria by using a high-resolution bioinformatics approach. We also provide compelling evidence of unique ARG-VF gene pairs coexisting in specific bacterial genomes and reveal the potential risk associated with the coexistence of ARGs and VFs in organisms in both clinical settings and environments.

scholarly journals F Plasmids Are the Major Carriers of Antibiotic Resistance Genes in Human-Associated Commensal Escherichia coli

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Craig Stephens ◽  
Tyler Arismendi ◽  
Megan Wright ◽  
Austin Hartman ◽  
Andres Gonzalez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Transposable Elements ◽  
Dna Sequencing ◽  
Resistance Genes ◽  
Bacterial Pathogens ◽  
Acquired Resistance ◽  
Antibiotic Resistance Genes ◽  
Content Type ◽  
E Coli

ABSTRACT The evolution and propagation of antibiotic resistance by bacterial pathogens are significant threats to global public health. Contemporary DNA sequencing tools were applied here to gain insight into carriage of antibiotic resistance genes in Escherichia coli, a ubiquitous commensal bacterium in the gut microbiome in humans and many animals, and a common pathogen. Draft genome sequences generated for a collection of 101 E. coli strains isolated from healthy undergraduate students showed that horizontally acquired antibiotic resistance genes accounted for most resistance phenotypes, the primary exception being resistance to quinolones due to chromosomal mutations. A subset of 29 diverse isolates carrying acquired resistance genes and 21 control isolates lacking such genes were further subjected to long-read DNA sequencing to enable complete or nearly complete genome assembly. Acquired resistance genes primarily resided on F plasmids (101/153 [67%]), with smaller numbers on chromosomes (30/153 [20%]), IncI complex plasmids (15/153 [10%]), and small mobilizable plasmids (5/153 [3%]). Nearly all resistance genes were found in the context of known transposable elements. Very few structurally conserved plasmids with antibiotic resistance genes were identified, with the exception of an ∼90-kb F plasmid in sequence type 1193 (ST1193) isolates that appears to serve as a platform for resistance genes and may have virulence-related functions as well. Carriage of antibiotic resistance genes on transposable elements and mobile plasmids in commensal E. coli renders the resistome highly dynamic. IMPORTANCE Rising antibiotic resistance in human-associated bacterial pathogens is a serious threat to our ability to treat many infectious diseases. It is critical to understand how acquired resistance genes move in and through bacteria associated with humans, particularly for species such as Escherichia coli that are very common in the human gut but can also be dangerous pathogens. This work combined two distinct DNA sequencing approaches to allow us to explore the genomes of E. coli from college students to show that the antibiotic resistance genes these bacteria have acquired are usually carried on a specific type of plasmid that is naturally transferrable to other E. coli, and likely to other related bacteria.

scholarly journals Antibiotic Resistance Genes in the Bacteriophage DNA Fraction of Human Fecal Samples

2013 ◽  
Vol 58 (1) ◽  
pp. 606-609 ◽  
Author(s):  
Pablo Quirós ◽  
Marta Colomer-Lluch ◽  
Alexandre Martínez-Castillo ◽  
Elisenda Miró ◽  
Marc Argente ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Real Time ◽  
Quantitative Pcr ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Fecal Samples ◽  
Real Time Quantitative Pcr ◽  
Healthy Humans ◽  
Phage Dna

ABSTRACTA group of antibiotic resistance genes (ARGs) (blaTEM,blaCTX-M-1,mecA,armA,qnrA, andqnrS) were analyzed by real-time quantitative PCR (qPCR) in bacteriophage DNA isolated from feces from 80 healthy humans. Seventy-seven percent of the samples were positive in phage DNA for one or more ARGs.blaTEM,qnrA, and,blaCTX-M-1were the most abundant, andarmA,qnrS, andmecAwere less prevalent. Free bacteriophages carrying ARGs may contribute to the mobilization of ARGs in intra- and extraintestinal environments.

scholarly journals Synthetic Fatty Acids Prevent Plasmid-Mediated Horizontal Gene Transfer

mBio ◽  
2015 ◽  
Vol 6 (5) ◽  
Author(s):  
María Getino ◽  
David J. Sanabria-Ríos ◽  
Raúl Fernández-López ◽  
Javier Campos-Gómez ◽  
José M. Sánchez-López ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Aliphatic Chain ◽  
Bacterial Conjugation ◽  
Human Pathogens

ABSTRACT Bacterial conjugation constitutes a major horizontal gene transfer mechanism for the dissemination of antibiotic resistance genes among human pathogens. Antibiotic resistance spread could be halted or diminished by molecules that interfere with the conjugation process. In this work, synthetic 2-alkynoic fatty acids were identified as a novel class of conjugation inhibitors. Their chemical properties were investigated by using the prototype 2-hexadecynoic acid and its derivatives. Essential features of effective inhibitors were the carboxylic group, an optimal long aliphatic chain of 16 carbon atoms, and one unsaturation. Chemical modification of these groups led to inactive or less-active derivatives. Conjugation inhibitors were found to act on the donor cell, affecting a wide number of pathogenic bacterial hosts, including Escherichia, Salmonella, Pseudomonas, and Acinetobacter spp. Conjugation inhibitors were active in inhibiting transfer of IncF, IncW, and IncH plasmids, moderately active against IncI, IncL/M, and IncX plasmids, and inactive against IncP and IncN plasmids. Importantly, the use of 2-hexadecynoic acid avoided the spread of a derepressed IncF plasmid into a recipient population, demonstrating the feasibility of abolishing the dissemination of antimicrobial resistances by blocking bacterial conjugation. IMPORTANCE Diseases caused by multidrug-resistant bacteria are taking an important toll with respect to human morbidity and mortality. The most relevant antibiotic resistance genes come to human pathogens carried by plasmids, mainly using conjugation as a transmission mechanism. Here, we identified and characterized a series of compounds that were active against several plasmid groups of clinical relevance, in a wide variety of bacterial hosts. These inhibitors might be used for fighting antibiotic-resistance dissemination by inhibiting conjugation. Potential inhibitors could be used in specific settings (e.g., farm, fish factory, or even clinical settings) to investigate their effect in the eradication of undesired resistances.

scholarly journals Genome-Resolved Metagenomics and Antibiotic Resistance Genes Analysis in Reclaimed Water Distribution Systems

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3477
Author(s):  
Changzhi Wang ◽  
Pei-Ying Hong
Keyword(s):  
Antibiotic Resistance ◽  
Relative Abundance ◽  
Resistance Genes ◽  
Distribution Systems ◽  
Water Distribution ◽  
Reclaimed Water ◽  
Water Distribution Systems ◽  
Antibiotic Resistance Genes ◽  
Quality Data ◽  
Metagenomic Data

Water reuse is increasingly pursued to alleviate global water scarcity. However, the wastewater treatment process does not achieve full removal of biological contaminants from wastewater, hence microorganisms and their genetic elements can be disseminated into the reclaimed water distribution systems (RWDS). In this study, reclaimed water samples are investigated via metagenomics to assess their bacterial diversity, metagenome-assembled genomes (MAGs) and antibiotic resistance genes (ARGs) at both point of entry (POE) and point of use (POU) in 3 RWDS. The number of shared bacterial orders identified by metagenome was higher at the POE than POU among the three sites, indicating that specific conditions in RWDS can cause further differentiation in the microbial communities at the end of the distribution system. Two bacterial orders, namely Rhizobiales and Sphingomonadales, had high replication rates in two of the examined RWDS (i.e., site A and B), and were present in higher relative abundance in POU than at POE. In addition, MAG and ARG relative abundance exhibited a strong correlation (R2 = 0.58) in POU, indicating that bacteria present in POU may have a high incidence of ARG. Specifically, resistance genes associated with efflux pump mechanisms (e.g., adeF and qacH) increased in its relative abundance from POU to POE at two of the RWDS (i.e., site A and B). When correlated with the water quality data that suggests a significantly lower dissolved organic carbon (DOC) concentration at site D than the other two RWDS, the metagenomic data suggest that low DOC is needed to maintain the biological stability of reclaimed water along the distribution network.

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