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Journal of Applied Microbiology Sep 2017Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of... (Review)
Review
Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm-blooded animals, including humans, and is often discharged into the environment through faeces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent faecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extraintestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a faecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long-term survival. Large-scale studies of population genetics revealed the diversity and complexity of E. coli strains in various environments, which are affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments with regard to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed.
Topics: Animals; Escherichia coli; Escherichia coli Infections; Feces; Fresh Water; Humans; Public Health; Water Pollution
PubMed: 28383815
DOI: 10.1111/jam.13468 -
Molecular Microbiology Jun 2006Pathogenic Escherichia coli cause over 160 million cases of dysentery and one million deaths per year, whereas non-pathogenic E. coli constitute part of the normal...
Pathogenic Escherichia coli cause over 160 million cases of dysentery and one million deaths per year, whereas non-pathogenic E. coli constitute part of the normal intestinal flora of healthy mammals and birds. The evolutionary pathways underlying this dichotomy in bacterial lifestyle were investigated by multilocus sequence typing of a global collection of isolates. Specific pathogen types [enterohaemorrhagic E. coli, enteropathogenic E. coli, enteroinvasive E. coli, K1 and Shigella] have arisen independently and repeatedly in several lineages, whereas other lineages contain only few pathogens. Rates of evolution have accelerated in pathogenic lineages, culminating in highly virulent organisms whose genomic contents are altered frequently by increased rates of homologous recombination; thus, the evolution of virulence is linked to bacterial sex. This long-term pattern of evolution was observed in genes distributed throughout the genome, and thereby is the likely result of episodic selection for strains that can escape the host immune response.
Topics: Alleles; Biological Evolution; Escherichia coli; Genes, Bacterial; Humans; Mutation; Phylogeny; Recombination, Genetic
PubMed: 16689791
DOI: 10.1111/j.1365-2958.2006.05172.x -
Applied and Environmental Microbiology Mar 2015Aldehydes are a class of chemicals with many industrial uses. Several aldehydes are responsible for flavors and fragrances present in plants, but aldehydes are not known... (Review)
Review
Aldehydes are a class of chemicals with many industrial uses. Several aldehydes are responsible for flavors and fragrances present in plants, but aldehydes are not known to accumulate in most natural microorganisms. In many cases, microbial production of aldehydes presents an attractive alternative to extraction from plants or chemical synthesis. During the past 2 decades, a variety of aldehyde biosynthetic enzymes have undergone detailed characterization. Although metabolic pathways that result in alcohol synthesis via aldehyde intermediates were long known, only recent investigations in model microbes such as Escherichia coli have succeeded in minimizing the rapid endogenous conversion of aldehydes into their corresponding alcohols. Such efforts have provided a foundation for microbial aldehyde synthesis and broader utilization of aldehydes as intermediates for other synthetically challenging biochemical classes. However, aldehyde toxicity imposes a practical limit on achievable aldehyde titers and remains an issue of academic and commercial interest. In this minireview, we summarize published efforts of microbial engineering for aldehyde synthesis, with an emphasis on de novo synthesis, engineered aldehyde accumulation in E. coli, and the challenge of aldehyde toxicity.
Topics: Aldehydes; Escherichia coli; Metabolic Engineering; Microbial Viability
PubMed: 25576610
DOI: 10.1128/AEM.03319-14 -
Clinical Microbiology Reviews Jul 2014In 2008, a previously unknown Escherichia coli clonal group, sequence type 131 (ST131), was identified on three continents. Today, ST131 is the predominant E. coli... (Review)
Review
In 2008, a previously unknown Escherichia coli clonal group, sequence type 131 (ST131), was identified on three continents. Today, ST131 is the predominant E. coli lineage among extraintestinal pathogenic E. coli (ExPEC) isolates worldwide. Retrospective studies have suggested that it may originally have risen to prominence as early as 2003. Unlike other classical group B2 ExPEC isolates, ST131 isolates are commonly reported to produce extended-spectrum β-lactamases, such as CTX-M-15, and almost all are resistant to fluoroquinolones. Moreover, ST131 E. coli isolates are considered to be truly pathogenic, due to the spectrum of infections they cause in both community and hospital settings and the large number of virulence-associated genes they contain. ST131 isolates therefore seem to contradict the widely held view that high levels of antimicrobial resistance are necessarily associated with a fitness cost leading to a decrease in pathogenesis. Six years after the first description of E. coli ST131, this review outlines the principal traits of ST131 clonal group isolates, based on the growing body of published data, and highlights what is currently known and what we need to find out to provide public health authorities with better information to help combat ST131.
Topics: Animals; Escherichia coli; Escherichia coli Infections; Genomics; Humans; Risk Factors; Virulence
PubMed: 24982321
DOI: 10.1128/CMR.00125-13 -
Scientific Reports Oct 2020Processing of animal carcasses and other animal wastes in rendering plants is a significant source of antibiotic resistant microorganisms. The main goal of this study...
Processing of animal carcasses and other animal wastes in rendering plants is a significant source of antibiotic resistant microorganisms. The main goal of this study was to investigate the resistance to 18 antibacterial agents including β-lactams, fluoroquinolones, colistin and virulence factors (iss, tsh, cvaC, iutA, papC, kps and ibeA genes) in 88 Escherichia coli strains isolated from a rendering plant over 1 year period. ESBL (Extended-spectrum beta-lactamases) and plasmid-mediated Amp were screened by interpretative reading of MIC. ESBL phenotype was detected in 20.4% of samples and high level of resistance to fluoroquinolone was found in 27.2% of strains. Cephalosporinase CTX-M1, cephamycinase CMY-2, integrase 1 and transposon 3 genes were detected by PCR. Furthermore, there were found three CMY-2 producing E. coli with O25b-ST131, resistant to the high level of enrofloxacin and containing the gene encoding the ferric aerobactin receptor (iutA). One enrofloxacin resistant E. coli strain possessed iss, ibeA, kps and papC virulence genes also with CMY-2, integrase1 and Tn3. ST131 E. coli with CMY-2 has a zoonotic potential and presents a serious health risk to humans.
Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Escherichia coli; Meat-Packing Industry; Microbial Sensitivity Tests; Polymerase Chain Reaction; Virulence; Virulence Factors; beta-Lactam Resistance
PubMed: 33051473
DOI: 10.1038/s41598-020-72851-5 -
Cell Sep 2015
Topics: Education, Graduate; Escherichia coli; Genetics, Microbial; History, 20th Century; Microbial Viability; New York
PubMed: 26359976
DOI: 10.1016/j.cell.2015.08.048 -
Nature Communications Feb 2018Self-assembly is a promising route for micro- and nano-fabrication with potential to revolutionise many areas of technology, including personalised medicine. Here we...
Self-assembly is a promising route for micro- and nano-fabrication with potential to revolutionise many areas of technology, including personalised medicine. Here we demonstrate that external control of the swimming speed of microswimmers can be used to self assemble reconfigurable designer structures in situ. We implement such 'smart templated active self assembly' in a fluid environment by using spatially patterned light fields to control photon-powered strains of motile Escherichia coli bacteria. The physics and biology governing the sharpness and formation speed of patterns is investigated using a bespoke strain designed to respond quickly to changes in light intensity. Our protocol provides a distinct paradigm for self-assembly of structures on the 10 μm to mm scale.
Topics: Escherichia coli; Kinetics; Light
PubMed: 29472614
DOI: 10.1038/s41467-018-03161-8 -
MicrobiologyOpen May 2019The aim of this study was to determine the serogroups, antimicrobial resistance and genetic diversity of Escherichia coli isolates from samples of bivalve mollusks...
The aim of this study was to determine the serogroups, antimicrobial resistance and genetic diversity of Escherichia coli isolates from samples of bivalve mollusks collected along Santa Catarina coast, Brazil, and from the Chesapeake Bay, Maryland, USA. One hundred forty-one E. coli isolates were characterized for serogroups with 181 specific O antisera and antimicrobial susceptibility using the disk diffusion method. The genetic diversity was assessed using pulsed-field gel electrophoresis (PFGE). The results showed that among the isolates, 19.9% were classified as multi-drug resistant (MDR) and resistance was most frequently observed to cephalothin, nitrofurantoin, and ampicillin. The predominant serogroups were O6, O8, and O38. Some serogroups were recognized as pathogenic E. coli. PFGE dendrograms indicated extensive genetic diversity among the isolates. Although characteristics of the E. coli isolates were highly variable, it is important to note that E. coli belonging to pathogenic serogroups and MDR isolates are present in mollusks of both study areas. This is the first report on the phenotypic and genotypic characterization of E. coli from mollusks from Santa Catarina and the Chesapeake Bay that should encourage studies focusing on comparison of isolates across countries.
Topics: Animals; Brazil; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Genetic Variation; Genotype; Genotyping Techniques; Maryland; Microbial Sensitivity Tests; Mollusca; Phenotype; Serotyping
PubMed: 30311420
DOI: 10.1002/mbo3.738 -
Ecotoxicology and Environmental Safety Sep 2021There are rising concerns about microbes harboring antibiotic resistance genes (ARGs) and virulence-associated genes (VAGs) in humans and food-producing animals....
There are rising concerns about microbes harboring antibiotic resistance genes (ARGs) and virulence-associated genes (VAGs) in humans and food-producing animals. Moreover, ARGs are considered as emerging environmental pollutants, posing probable life-threatening complications in humans and animals. Commensal Escherichia coli (E. coli) strain can carry a large number of VAGs, which may become opportunistic pathogen. The objective of this study was to determine the prevalence and possible association of ARGs and VAGs in E. coli isolates from clinically healthy waterfowls in China's tropical island, Hainan. For this purpose, 311 non-repeating E. coli isolates were evaluated for phenotypic drug resistance linked with ARGs. Additionally, strains were examined for subsequent resistance and virulence genes by uniplex or multiplex PCR and sequencing. Overall, 89 types of antibiotic resistance patterns were analysed, while 25 ARGs and 23 VAGs were observed, of which qnrS (99.4%) and iucD (99.7%) were the most commonly found genes, respectively. Significant positive associations were observed among ARGs and VAGs (p<0.05, OR>1). The strongest association between resistance and virulence gene was observed for qnrS and iss (OR, 76.25; 95% CI, 4.02-1445.42). Our results propose that waterfowls serve as a reservoir of E. coli carrying multi ARGs and various ExPEC associated VAGs. Therefore, this study provides necessary information on the occurrence and possible associations of ARGs and VAGs in healthy waterfowls, which may act as a reference for the regulatory use of antibiotics to stop the direct or indirect spread of these resistant and potential virulent microbes to natural environment.
Topics: Animals; Animals, Wild; Anti-Bacterial Agents; Bird Diseases; China; Drug Resistance, Bacterial; Ducks; Escherichia coli; Escherichia coli Infections; Geese; Virulence
PubMed: 34049228
DOI: 10.1016/j.ecoenv.2021.112317 -
Microbial Cell Factories Mar 2021Escherichia coli is generally used as model bacteria to define microbial cell factories for many products and to investigate regulation mechanisms. E. coli exhibits... (Review)
Review
Escherichia coli is generally used as model bacteria to define microbial cell factories for many products and to investigate regulation mechanisms. E. coli exhibits phospholipids, lipopolysaccharides, colanic acid, flagella and type I fimbriae on the outer membrane which is a self-protective barrier and closely related to cellular morphology, growth, phenotypes and stress adaptation. However, these outer membrane associated molecules could also lead to potential contamination and insecurity for fermentation products and consume lots of nutrients and energy sources. Therefore, understanding critical insights of these membrane associated molecules is necessary for building better microbial producers. Here the biosynthesis, function, influences, and current membrane engineering applications of these outer membrane associated molecules were reviewed from the perspective of synthetic biology, and the potential and effective engineering strategies on the outer membrane to improve fermentation features for microbial cell factories were suggested.
Topics: Bacterial Outer Membrane; Cell Engineering; Escherichia coli; Escherichia coli Proteins; Fermentation; Synthetic Biology
PubMed: 33743682
DOI: 10.1186/s12934-021-01565-8