scholarly journals Temporal Variability ofEscherichia coliDiversity in the Gastrointestinal Tracts of Tanzanian Children with and without Exposure to Antibiotics

mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Taylor K. S. Richter ◽  
Tracy H. Hazen ◽  
Diana Lam ◽  
Christian L. Coles ◽  
Jessica C. Seidman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Tract ◽  
Antimicrobial Resistance ◽  
Antibiotic Treatment ◽  
Genomic Diversity ◽  
Human Gastrointestinal Tract ◽  
Content Type ◽  
E Coli ◽  
Time Points ◽  
Antimicrobial Resistance Genes

ABSTRACTThe stability of theEscherichia colipopulations in the human gastrointestinal tract is not fully appreciated, and represents a significant knowledge gap regarding gastrointestinal community structure, as well as resistance to incoming pathogenic bacterial species and antibiotic treatment. The current study examines the genomic content of 240Escherichia coliisolates from 30 children, aged 2 to 35 months old, in Tanzania. TheE. colistrains were isolated from three time points spanning a six-month time period, with and without antibiotic treatment. The resulting isolates were sequenced, and the genomes compared. The findings in this study highlight the transient nature ofE. colistrains in the gastrointestinal tract of these children, as during a six-month interval, no one individual contained phylogenomically related isolates at all three time points. While the majority of the isolates at any one time point were phylogenomically similar, most individuals did not contain phylogenomically similar isolates at more than two time points. Examination of global genome content, canonicalE. colivirulence factors, multilocus sequence type, serotype, and antimicrobial resistance genes identified diversity even among phylogenomically similar strains. There was no apparent increase in the antimicrobial resistance gene content after antibiotic treatment. The examination of theE. colifrom longitudinal samples from multiple children in Tanzania provides insight into the genomic diversity and population variability of residentE. coliwithin the rapidly changing environment of the gastrointestinal tract of these children.IMPORTANCEThis study increases the number of residentEscherichia coligenome sequences, and exploresE. colidiversity through longitudinal sampling. We investigate the genomes ofE. coliisolated from human gastrointestinal tracts as part of an antibiotic treatment program among rural Tanzanian children. Phylogenomics demonstrates that residentE. coliare diverse, even within a single host. Though theE. coliisolates of the gastrointestinal community tend to be phylogenomically similar at a given time, they differed across the interrogated time points, demonstrating the variability of the members of theE. colicommunity in these subjects. Exposure to antibiotic treatment did not have an apparent impact on theE. colicommunity or the presence of resistance and virulence genes withinE. coligenomes. The findings of this study highlight the variable nature of specific bacterial members of the human gastrointestinal tract.

scholarly journals Population dynamics of Escherichia coli in the gastrointestinal tracts of Tanzanian children

2018 ◽  
Author(s):  
Taylor K. S. Richter ◽  
Tracy H. Hazen ◽  
Diana Lam ◽  
Christian L. Coles ◽  
Jessica C. Seidman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Tract ◽  
Antimicrobial Resistance ◽  
Antibiotic Treatment ◽  
Genomic Diversity ◽  
Human Gastrointestinal Tract ◽  
E Coli ◽  
Time Points ◽  
Antimicrobial Resistance Genes ◽  
Variable Nature

AbstractThe stability of the Escherichia coli populations in the human gastrointestinal tract are not fully appreciated, and represent a significant knowledge gap regarding gastrointestinal community structure, as well as resistance to incoming pathogenic bacterial species and antibiotic treatment. The current study examines the genomic content of 240 Escherichia coli isolates from children 2 to 35 months old in Tanzania. The E. coli strains were isolated from three time points spanning a six month time period, with or without antibiotic treatment. The resulting isolates were sequenced, and the genomes compared. The findings in this study highlight the transient nature of E. coli strains in the gastrointestinal tract of children, as during a six-month interval, no one individual contained phylogenomically related isolates at all three time points. While the majority of the isolates at any one time point were phylogenomically similar, most individuals did not contain phylogenomically similar isolates at more than two time points. Examination of global genome content, canonical E. coli virulence factors, multilocus sequence type, serotype, and antimicrobial resistance genes identified diversity even among phylogenomically similar strains. There was no apparent increase in the antimicrobial resistance gene content after antibiotic treatment. The examination of the E. coli from longitudinal samples from multiple children in Tanzania provides insight into the genomic diversity and population variability of resident E. coli within the rapidly changing environment of the gastrointestinal tract.ImportanceThis study increases the number of resident Escherichia coli genome sequences, and explores E. coli diversity through longitudinal sampling. We investigate the genomes of E. coli isolated from human gastrointestinal tracts as part of an antibiotic treatment program among rural Tanzanian children. Phylogenomics demonstrates that resident E. coli are diverse, even within a single host. Though the E. coli isolates of the gastrointestinal community tend to be phylogenomically similar at a given time, they differed across the interrogated time points, demonstrating the variability of the members of the E. coli community. Exposure to antibiotic treatment did not have an apparent impact on the E. coli community or the presence of resistance and virulence genes within E. coli genomes. The findings of this study highlight the variable nature of bacterial members of the human gastrointestinal tract.

scholarly journals Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

2014 ◽  
Vol 80 (12) ◽  
pp. 3656-3666 ◽  
Author(s):  
Basanta Kumar Biswal ◽  
Ramzi Khairallah ◽  
Kareem Bibi ◽  
Alberto Mazza ◽  
Ronald Gehr ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Peracetic Acid ◽  
Content Type ◽  
E Coli ◽  
Antimicrobial Resistance Genes ◽  
Antimicrobial Resistance Gene ◽  
Municipal Wastewaters ◽  
The Impact

ABSTRACTWastewater discharges may increase the populations of pathogens, includingEscherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenicEscherichia coli(UPEC), the most abundantE. colipathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766E. coliisolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm2and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters.

scholarly journals Genomic surveillance of Escherichia coli and Klebsiella spp. in hospital sink drains and patients

2020 ◽  
Vol 6 (7) ◽  
Author(s):  
Bede Constantinides ◽  
Kevin K. Chau ◽  
T. Phuong Quan ◽  
Gillian Rodger ◽  
Monique I. Andersson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Type Species ◽  
Whole Genome ◽  
Content Type ◽  
E Coli ◽  
Link Type ◽  
Antimicrobial Resistance Genes

Escherichia coli and Klebsiella spp. are important human pathogens that cause a wide spectrum of clinical disease. In healthcare settings, sinks and other wastewater sites have been shown to be reservoirs of antimicrobial-resistant E. coli and Klebsiella spp., particularly in the context of outbreaks of resistant strains amongst patients. Without focusing exclusively on resistance markers or a clinical outbreak, we demonstrate that many hospital sink drains are abundantly and persistently colonized with diverse populations of E. coli , Klebsiella pneumoniae and Klebsiella oxytoca , including both antimicrobial-resistant and susceptible strains. Using whole-genome sequencing of 439 isolates, we show that environmental bacterial populations are largely structured by ward and sink, with only a handful of lineages, such as E. coli ST635, being widely distributed, suggesting different prevailing ecologies, which may vary as a result of different inputs and selection pressures. Whole-genome sequencing of 46 contemporaneous patient isolates identified one (2 %; 95 % CI 0.05–11 %) E. coli urine infection-associated isolate with high similarity to a prior sink isolate, suggesting that sinks may contribute to up to 10 % of infections caused by these organisms in patients on the ward over the same timeframe. Using metagenomics from 20 sink-timepoints, we show that sinks also harbour many clinically relevant antimicrobial resistance genes including bla CTX-M, bla SHV and mcr, and may act as niches for the exchange and amplification of these genes. Our study reinforces the potential role of sinks in contributing to Enterobacterales infection and antimicrobial resistance in hospital patients, something that could be amenable to intervention. This article contains data hosted by Microreact.

scholarly journals Salmonella Genomic Island 1B Variant Found in a Sequence Type 117 Avian Pathogenic Escherichia coli Isolate

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Max Laurence Cummins ◽  
Piklu Roy Chowdhury ◽  
Marc Serge Marenda ◽  
Glenn Francis Browning ◽  
Steven Philip Djordjevic
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Acinetobacter Baumannii ◽  
Genome Sequencing ◽  
Genomic Island ◽  
Sequence Type ◽  
Genomic Islands ◽  
Content Type ◽  
E Coli ◽  
Antimicrobial Resistance Genes

ABSTRACT Salmonella genomic island 1 (SGI1) is an integrative genetic island first described in Salmonella enterica serovars Typhimurium DT104 and Agona in 2000. Variants of it have since been described in multiple serovars of S. enterica, as well as in Proteus mirabilis, Acinetobacter baumannii, Morganella morganii, and several other genera. The island typically confers resistance to older, first-generation antimicrobials; however, some variants carry blaNDM-1, blaVEB-6, and blaCTX-M15 genes that encode resistance to frontline, clinically important antibiotics, including third-generation cephalosporins. Genome sequencing studies of avian pathogenic Escherichia coli (APEC) identified a sequence type 117 (ST117) isolate (AVC96) with genetic features found in SGI1. The complete genome sequence of AVC96 was assembled from a combination of Illumina and single-molecule real-time (SMRT) sequence data. Analysis of the AVC96 chromosome identified a variant of SGI1-B located 18 bp from the 3′ end of trmE, also known as the attB site, a known hot spot for the integration of genomic islands. This is the first report of SGI1 in wild-type E. coli. The variant, here named SGI1-B-Ec1, was otherwise unremarkable, apart from the identification of ISEc43 in open reading frame (ORF) S023. IMPORTANCE SGI1 and variants of it carry a variety of antimicrobial resistance genes, including those conferring resistance to extended-spectrum β-lactams and carbapenems, and have been found in diverse S. enterica serovars, Acinetobacter baumannii, and other members of the Enterobacteriaceae. SGI1 integrates into Gram-negative pathogenic bacteria by targeting a conserved site 18 bp from the 3′ end of trmE. For the first time, we describe a novel variant of SGI1 in an avian pathogenic Escherichia coli isolate. The presence of SGI1 in E. coli is significant because it represents yet another lateral gene transfer mechanism to enhancing the capacity of E. coli to acquire and propagate antimicrobial resistance and putative virulence genes. This finding underscores the importance of whole-genome sequencing (WGS) to microbial genomic epidemiology, particularly within a One Health context. Further studies are needed to determine how widespread SGI1 and variants of it may be in Australia.

scholarly journals Responses of the Human GutEscherichia coliPopulation to Pathogen and Antibiotic Disturbances

mSystems ◽  
2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Taylor K. S. Richter ◽  
Jane M. Michalski ◽  
Luke Zanetti ◽  
Sharon M. Tennant ◽  
Wilbur H. Chen ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Antibiotic Treatment ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Whole Genome ◽  
Human Gastrointestinal Tract ◽  
Content Type ◽  
E Coli ◽  
Pathogen Invasion

ABSTRACTStudies ofEscherichia coliin the human gastrointestinal tract have focused on pathogens, such as diarrhea-causing enterotoxigenicE. coli(ETEC), while overlooking the resident, nonpathogenicE. colicommunity. Relatively few genomes of nonpathogenicE. colistrains are available for comparative genomic analysis, and the ecology of these strains is poorly understood. This study examined the diversity and dynamics of resident human gastrointestinalE. colicommunities in the face of the ecological challenges presented by pathogen (ETEC) challenge, as well as of antibiotic treatment. Whole-genome sequences obtained fromE. coliisolates from before, during, and after ETEC challenge were used in phylogenomic and comparative genomic analyses to examine the diversity of the residentE. colicommunities, as well as the dynamics of the challenge strain, H10407, a well-studied ETEC strain (serotype O78:H11) that produces both heat-labile and heat-stable enterotoxins. ETEC failed to become the dominantE. coliclone in two of the six challenge subjects, each of whom exhibited limited or no clinical presentation of diarrhea. TheE. colicommunities of the remaining four subjects became ETEC dominant during the challenge but reverted to their original, subject-specific populations following antibiotic treatment, suggesting resiliency of the residentE. colipopulation following major ecological disruptions. This resiliency is likely due in part to the abundance of antibiotic-resistant ST131E. colistrains in the resident populations. This report provides valuable insights into the potential interactions of members of the gastrointestinal microbiome and its responses to challenge by an external pathogen and by antibiotic exposure.IMPORTANCEResearch on human-associatedE. colitends to focus on pathogens, such as enterotoxigenicE. coli(ETEC) strains, which are a leading cause of diarrhea in developing countries. However, the severity of disease caused by these pathogens is thought to be influenced by the microbiome. The nonpathogenicE. colicommunity that resides in the human gastrointestinal tract may play a role in pathogen colonization and disease severity and may become a reservoir for virulence and antibiotic resistance genes. Our study used whole-genome sequencing ofE. colibefore, during, and after challenge with an archetype ETEC isolate, H10407, and antibiotic treatment to explore the diversity and resiliency of the residentE. colipopulation in response to the ecological disturbances caused by pathogen invasion and antibiotic treatment.

scholarly journals Plasmid Sequences of Four Large Plasmids Carrying Antimicrobial Resistance Genes in Escherichia coli Strains Isolated from Beef Cattle in Japan

2020 ◽  
Vol 9 (20) ◽  
Author(s):  
Shiori Yamamoto ◽  
Wataru Kitagawa ◽  
Motoki Nakano ◽  
Hiroshi Asakura ◽  
Eriko Iwabuchi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Beef Cattle ◽  
Resistance Genes ◽  
Content Type ◽  
E Coli ◽  
Antimicrobial Resistance Genes ◽  
Resistance Plasmids ◽  
Large Plasmids

Escherichia coli is a common reservoir for antimicrobial resistance genes that can be easily transformed to possess multidrug resistance through plasmid transfer. To understand multidrug resistance plasmids, we report the plasmid sequences of four large plasmids carrying a number of genes related to antimicrobial resistance that were found in E. coli strains isolated from beef cattle.

scholarly journals Diverse Commensal Escherichia coli Clones and Plasmids Disseminate Antimicrobial Resistance Genes in Domestic Animals and Children in a Semirural Community in Ecuador

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Liseth Salinas ◽  
Paúl Cárdenas ◽  
Timothy J. Johnson ◽  
Karla Vasco ◽  
Jay Graham ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Multidrug Resistant ◽  
Domestic Animals ◽  
Whole Genome ◽  
Content Type ◽  
Phenotypic Resistance ◽  
E Coli ◽  
Antimicrobial Resistance Genes

ABSTRACT The increased prevalence of antimicrobial resistance (AMR) among Enterobacteriaceae has had major clinical and economic impacts on human medicine. Many of the multidrug-resistant (multiresistant) Enterobacteriaceae found in humans are community acquired, and some of them are possibly linked to food animals (i.e., livestock raised for meat and dairy products). In this study, we examined whether numerically dominant commensal Escherichia coli strains from humans (n = 63 isolates) and domestic animals (n = 174 isolates) in the same community and with matching phenotypic AMR patterns were clonally related or shared the same plasmids. We identified 25 multiresistant isolates (i.e., isolates resistant to more than one antimicrobial) that shared identical phenotypic resistance patterns. We then investigated the diversity of E. coli clones, AMR genes, and plasmids carrying the AMR genes using conjugation, replicon typing, and whole-genome sequencing. All of the multiresistant E. coli isolates (from children and domestic animals) analyzed had at least 90 or more whole-genome SNP differences between one another, suggesting that none of the strains was recently transferred. While the majority of isolates shared the same antimicrobial resistance genes and replicons, DNA sequencing indicated that these genes and replicons were found on different plasmid structures. We did not find evidence of the clonal spread of AMR in this community: instead, AMR genes were carried on diverse clones and plasmids. This presents a significant challenge for understanding the movement of AMR in a community. IMPORTANCE Even though Escherichia coli strains may share nearly identical phenotypic AMR profiles and AMR genes and overlap in space and time, the diversity of clones and plasmids challenges research that aims to identify sources of AMR. Horizontal gene transfer appears to play a more significant role than clonal expansion in the spread of AMR in this community.

Antimicrobial resistance genes and genetic characteristics of multidrug-resistant Escherichia coli in a veterinary hospital in Taiwan

2021 ◽  
Vol 70 (11) ◽  
Author(s):  
Lii-Tzu Wu ◽  
Xin-Xia Wu ◽  
Se-Chin Ke ◽  
Yi-Pei Lin ◽  
Ying-Chen Wu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Type Species ◽  
Multidrug Resistant ◽  
Content Type ◽  
E Coli ◽  
Link Type ◽  
Antimicrobial Resistance Genes ◽  
Veterinary Hospital

Introduction. Antimicrobial resistance associated with animal hosts is easily transmitted to humans either by direct contact with resistant organisms or by transferring resistance genes into human pathogens. Gap statement. There are limited studies on antimicrobial resistance genes and genetic elements of multidrug-resistant (MDR) Escherichia coli in veterinary hospitals in Taiwan. Aim. The aim of this study was to investigate antimicrobial resistance genes in multidrug-resistant Escherichia coli from animals. Methodology. Between January 2014 and August 2015, 95 multidrug-resistant Escherichia coli isolates were obtained from pigs (n=66), avians (n=18), and other animals (n=11) in a veterinary hospital in Taiwan. Susceptibility testing to 24 antimicrobial agents of 14 antimicrobial classes was performed. Antimicrobial resistance genes, integrons, and insertion sequences were analysed by polymerase chain reaction and nucleotide sequencing. Pulsed-field gel electrophoresis (PFGE), and multi-locus sequence typing were used to explore the clonal relatedness of the study isolates. Results. Different antimicrobial resistance genes found in these isolates were associated with resistance to β-lactams, tetracycline, phenicols, sulfonamides, and aminoglycosides. Fifty-five of 95 E. coli isolates (55/95, 57.9 %) were not susceptible to extended-spectrum cephalosporins, and bla CTX-M-55 (11/55, 20.0 %) and bla CMY-2 (40/55, 72.7 %) were the most common extended-spectrum β-lactamase (ESBL) and AmpC genes, respectively. Both bla CTX-M and bla CMY-2 were present on conjugative plasmids that contained the insertion sequence ISEcp1 upstream of the bla genes. Plasmid-mediated FOX-3 β-lactamase-producing E. coli was first identified in Taiwan. Forty isolates (40/95, 42 %) with class 1 integrons showed seven resistance phenotypes. Genotyping of 95 E. coli isolates revealed 91 different XbaI pulsotypes and 52 different sequence types. PFGE analysis revealed no clonal outbreaks in our study isolates. Conclusion. This study showed a high diversity of antimicrobial resistance genes and genotypes among MDR E. coli isolated from diseased livestock in Taiwan. To our knowledge, this is the first report of plasmid-mediated ESBL in FOX-3 β-lactamase-producing E. coli isolates in Taiwan. MDR E. coli isolates from animal origins may contaminate the environment, resulting in public health concerns, indicating that MDR isolates from animals need to be continuously investigated.

scholarly journals Population genomics and antimicrobial resistance dynamics of Escherichia coli in wastewater and river environments

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jose F. Delgado-Blas ◽  
Cristina M. Ovejero ◽  
Sophia David ◽  
Natalia Montero ◽  
William Calero-Caceres ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Population Genomics ◽  
Population Diversity ◽  
Genomic Diversity ◽  
Resistant Bacteria ◽  
Aquatic Environments ◽  
E Coli ◽  
Water Ecosystems ◽  
Sequence Types

AbstractAquatic environments are key niches for the emergence, evolution and dissemination of antimicrobial resistance. However, the population diversity and the genetic elements that drive the dynamics of resistant bacteria in different aquatic environments are still largely unknown. The aim of this study was to understand the population genomics and evolutionary events of Escherichia coli resistant to clinically important antibiotics including aminoglycosides, in anthropogenic and natural water ecosystems. Here we show that less different E. coli sequence types (STs) are identified in wastewater than in rivers, albeit more resistant to antibiotics, and with significantly more plasmids/cell (6.36 vs 3.72). However, the genomic diversity within E. coli STs in both aquatic environments is similar. Wastewater environments favor the selection of conserved chromosomal structures associated with diverse flexible plasmids, unraveling promiscuous interplasmidic resistance genes flux. On the contrary, the key driver for river E. coli adaptation is a mutable chromosome along with few plasmid types shared between diverse STs harboring a limited resistance gene content.

scholarly journals Species-Wide Collection of Escherichia coli Isolates for Examination of Genomic Diversity

2017 ◽  
Vol 5 (50) ◽  
Author(s):  
Jayanthi Gangiredla ◽  
Mark K. Mammel ◽  
Tammy J. Barnaba ◽  
Carmen Tartera ◽  
Solomon T. Gebru ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Human Health ◽  
Potential Risk ◽  
Phylogenetic Relationships ◽  
Genomic Diversity ◽  
Genome Sequences ◽  
Content Type ◽  
E Coli

ABSTRACT Pathogenic and nonpathogenic Escherichia coli strains present a vast genomic diversity. We report the genome sequences of 2,244 E. coli isolates from multiple animal and environmental sources. Their phylogenetic relationships and potential risk to human health were examined.

Sign in / Sign up

Export Citation Format

Share Document