scholarly journals Genetic diversity of Escherichia coli isolates from surface water and groundwater in a rural environment

2017 ◽  
Vol 15 (5) ◽  
pp. 757-765 ◽  
Author(s):  
Maria Laura Gambero ◽  
Monica Blarasin ◽  
Susana Bettera ◽  
Jesica Giuliano Albo
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Surface Water ◽  
Water Contamination ◽  
Fecal Contamination ◽  
Genotypic Diversity ◽  
Human Consumption ◽  
Genetic Characteristics ◽  
E Coli ◽  
Surface Water And Groundwater

The genetic characteristics among Escherichia coli strains can be grouped by origin of isolation. Then, it is possible to use the genotypes as a tool to determine the source of water contamination. The aim of this study was to define water aptitude for human consumption in a rural basin and to assess the diversity of E. coli water populations. Thus, it was possible to identify the main sources of fecal contamination and to explore linkages with the hydrogeological environment and land uses. The bacteriological analysis showed that more than 50% of samples were unfit for human consumption. DNA fingerprinting analysis by BOX-PCR indicated low genotypic diversity of E. coli isolates taken from surface water and groundwater. The results suggested the presence of a dominant source of fecal contamination. The relationship between low genotypic diversity and land use would prove that water contamination comes from livestock. The genetic diversity of E. coli isolated from surface water was less than that identified in groundwater because of the different hydraulic features of both environments. Furthermore, each one of the two big strain groups identified in this basin is located in different sub-basins, showing that hydrological dynamics exerts selective pressure on bacteria DNA.

scholarly journals Effects of hydrological regime and land use on in-stream Escherichia coli concentration in the Mekong basin, Lao PDR

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paty Nakhle ◽  
Olivier Ribolzi ◽  
Laurie Boithias ◽  
Sayaphet Rattanavong ◽  
Yves Auda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Land Use ◽  
Surface Water ◽  
Stream Water ◽  
Fecal Contamination ◽  
Lao Pdr ◽  
Fecal Matter ◽  
E Coli ◽  
Sampling Campaign ◽  
Tropical Conditions

AbstractIn the basin of Mekong, over 70 million people rely on unimproved surface water for their domestic requirements. Surface water is often contaminated with fecal matter and yet little information exists on the underlying mechanisms of fecal contamination in tropical conditions at large watershed scales. Our objectives were to (1) investigate the seasonality of fecal contamination using Escherichia coli as fecal indicator bacteria (FIB), and (2) establish links between the fecal contamination in stream water and its controlling factors (hydrology and land use). We present the results of (1) a sampling campaign at the outlet of 19 catchments across Lao PDR, in both the dry and the rainy seasons of 2016, and (2) a 10-day interval monitoring conducted in 2017 and 2018 at three point locations of three rivers (Nam Ou, Nam Suang, and Mekong) in northern Lao PDR. Our results show the presence of fecal contamination at most of the sampled sites, with a seasonality characterized by higher and extreme E. coli concentrations occurring during the rainy season. The highest E. coli concentrations, strongly correlated with total suspended sediment concentrations, were measured in catchments dominated by unstocked forest areas, especially in mountainous northern Lao PDR and in Vientiane province.

scholarly journals Genetic diversity and antimicrobial resistance of Escherichia coli as microbial source tracking tools of Karaj River, Iran

2017 ◽  
Vol 17 (5) ◽  
pp. 1468-1478
Author(s):  
Roohollah Kheiri ◽  
Leili Akhtari
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Antimicrobial Resistance ◽  
Microbial Source Tracking ◽  
Source Tracking ◽  
Enterobacterial Repetitive Intergenic Consensus ◽  
Genetic Characteristics ◽  
Sample Group ◽  
E Coli ◽  
Cattle Faeces

The aim of this study was to analyze the enterobacterial repetitive intergenic consensus (ERIC)-types, phylo-groups and antimicrobial resistance (AMR) patterns of Escherichia coli and to investigate if these approaches are suitable for microbial source tracking (MST). E. coli strains were isolated from cattle faeces and Karaj River. For genetic diversity, AMR profile, and phylo-grouping, we applied ERIC-PCR, disk diffusion, and multiplex-PCR, respectively. Fifty isolates from each sample group were used in the study. ERIC fingerprinting produced ten different bands, demonstrating 64 unique and 36 repetitive profiles. Six isolates from the river showed the same ERIC pattern of the cattle, of which four expressed the same AMR profile. E. coli isolates from water were represented in A, B1, C, and D phylo-groups. Phylo-groups A, B1, and E were more prevalent in the cattle isolates and B2 was absent in both sources. Three of the water isolates with the same ERIC-type and AMR to cattle isolates showed the same phylo-groups. Genetic characteristics, AMR, and phylo-groups of the isolates from the river are diverse and complex. For accurate MST, complementary approaches should be applied together and a comprehensive library should be provided.

scholarly journals Using GFP-Tagged Escherichia coli to Investigate the Persistence of Fecal Bacteria in Vegetated Wetlands: An Experimental Approach

Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 335
Author(s):  
Emilia Chiapponi ◽  
Charles P. Henriot ◽  
Xavier Bertrand ◽  
Didier Hocquet ◽  
Gudrun Bornette
Keyword(s):  
Escherichia Coli ◽  
Surface Water ◽  
Water Column ◽  
Pathogenic Bacteria ◽  
Fluorescent Protein ◽  
Fecal Contamination ◽  
Public Health Issue ◽  
Fecal Bacteria ◽  
Bacterial Survival ◽  
E Coli

The contamination of surface water by pathogenic bacteria of human origin is an important public health issue. Wetlands can be contaminated with fecal bacteria by water originating from different sources, such as wastewater treatment plants and agriculture. Escherichia coli is a commensal of the human gut flora and the major indication of fecal contamination in surface water. Little is known about the association between fecal bacteria and submerged macrophytes and how this may influence the water quality. We questioned whether macrophytes enhance or inhibit the bacterial growth in wetlands. For this purpose, we grew four different species of macrophytes (Mentha aquatica, Baldellia ranunculoides, Sparganium emersum and Elodea canadensis, in mono- or multispecies cultures) in aquatic rhizotrons and inoculated the devices with a fluorescent strain of Escherichia coli (producing a green fluorescent protein) to simulate the fecal contamination of wetlands. Bacterial survival was monitored by measuring the fluorescence for 19 days. We found (i) that contaminated sediments did not release E. coli in the water column in lentic conditions and (ii) that monocultures of E. canadensis, M. aquatica and S. emersum reduced the E. coli concentration in the water column. This suggests that aquatic plant species may be used in constructed wetlands to clear surface freshwater from bacteria of fecal origin.

Uneven genotypic diversity of Escherichia coli in fecal sources limits the performance of a library-dependent method of microbial source tracking on the southwestern French Atlantic coast

2020 ◽  
Vol 66 (12) ◽  
pp. 698-712
Author(s):  
Frédéric Garabetian ◽  
Isabelle Vitte ◽  
Antoine Sabourin ◽  
Hélène Moussard ◽  
Adeline Jouanillou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Source Identification ◽  
Diversity Index ◽  
Atlantic Coast ◽  
Fecal Contamination ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Genotypic Diversity ◽  
Support Vector ◽  
E Coli

To develop a library-dependent method of tracking fecal sources of contamination of beaches on the Atlantic coast of southwestern France, a library of 6368 Escherichia coli isolates was constructed from samples of feces, from 40 known human or animal sources collected in the vicinity of Arcachon Bay in 2010, and in French Basque Country, Landes, and Béarn, between 2017 and 2018. Different schemes of source identification were tested: use of the complete or filtered reference library; characterization of the isolates by genotypic or proteomic profiling based on ERIC-PCR or MALDI-TOF mass spectrometry, respectively; isolate by isolate assignment using either classifiers based on the Pearson similarity or SVM (support vector machine). With the exception of one source identification scheme, which was discarded since it used self-assignment, all tested schemes resulted in low rates of correct classification (<35%) and significant rates of incorrect classification (>15%). The heterogeneous coverage of E. coli genotypic diversity between sources and the uneven distribution of E. coli genotypes in the library likely explain the difficulties encountered in identifying the sources of fecal contamination. Shannon diversity index of sources ranged from 0 for several wildlife species sampled once to 3.03 for sewage treatment plant effluents sampled on various occasions, showing discrepancies between sources. The uneven genotypic composition of the library was attested by the value of the Pielou index (0.54), the high proportion of nondiscriminatory genotypes (>91% of the isolates), and the very low proportion of discriminatory genotypes (<3%). Since efforts made to constitute such a library are not affordable for routine analyses, the results question the relevance of developing such a method for identifying sources of fecal contamination on such a coastline.

scholarly journals Genotypic Diversity and Antimicrobial Resistance of Escherichia Coli Isolated From Pigs in Hubei, China

2021 ◽  
Author(s):  
Xiaoyue Li ◽  
Zewen Liu ◽  
Ningning Wang ◽  
Wei Liu ◽  
Ting Gao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Genotypic Diversity ◽  
Hubei Province ◽  
Economic Losses ◽  
Multi Drug Resistance ◽  
Growth Delay ◽  
E Coli

Abstract BackgroundIntestinal infections with Escherichia coli (E. coli) are mostly occur in piglets between 1~10 days old, which major lead to diarrhea and edema in newborn piglets. These diseases caused by E. coli can increase mortality, morbidity and growth delay of piglets, which are responsible for economic losses. In this study was to investigate the prevalence of antibiotic resistance, transmission mechanisms, and molecular epidemiology of E. coli strains isolated from pig farms in Hubei province. Furthermore, clonal and genetic diversity of isolates were identified. ResultsA total of 29 E. coli isolates were obtained from fecal of weaned piglets from Hubei province. The E. coli isolates in different regions demonstrate different genetic diversity. Multilocus sequence typing (MLST) presented that ST165 was the common sequence type, accounting for 27.6% of all E. coli isolates, followed by ST744, ST1081, ST101 and ST10. All of the isolates were resistant to the tested antibiotics to vary degrees, and more than 80% of E. coli isolates presented high resistance rates to ampicillin, lincomycin, doxycycline, tetracycline, sulfaisoxazole and ampicillin. There was one E. coli strain that was resistant to the fifteen antimicrobial agents tested. Overall, most of the isolates were conferring resistance to 5-7 antimicrobial agents tested.ConclusionsOur study reported E. coli isolates with high antimicrobial resistance and explores the genetic diversity of E. coli isolated from swine-origin. From the results obtained it can be concluded that these isolates present high prevalent multi-drug resistance. These data provide a greater understanding of the genetic diversity and antimicrobial resistance of E. coli.

The use of antibiotic resistance profiling as a means of tracing sources of fecal contamination in source waters

2010 ◽  
Vol 10 (2) ◽  
pp. 209-215
Author(s):  
M. S. Mthembu ◽  
P. T. Biyela ◽  
T. G. Djarova ◽  
A. K. Basson
Keyword(s):  
Antibiotic Resistance ◽  
Municipal Wastewater ◽  
Fecal Contamination ◽  
Source Tracking ◽  
Human Consumption ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
E Coli ◽  
Intestinal Pathogens ◽  
Source Waters

Fecal contamination of source waters and its associated intestinal pathogens continues to pose risks to public health although the extent and effect of microbial contamination of source waters gets very little attention in designing treatment plants in most developing countries. Coliform counts give an indication of the overall bacterial contamination of water and thus its safety for human consumption. However, their presence fails to provide information about the source of fecal contamination which is vital to managing fecal contamination problems in surface waters. This study explored the use of multiple antibiotic resistance (MAR) indexing as means of differentiating E. coli isolates from different sources. A total of 322 E. coli isolates were obtained from municipal wastewater and from fecal samples from domestic and wild animals. Conventional culture methods and standard chemical and biochemical tests were used for isolation and identification of E. coli. Isolates were assayed against 10 antibiotics using the micro-dilution technique. The results obtained generated antibiotic resistance profiles which were used to statistically group the isolates into different subsets. Correct source classification was obtained for 60% of human-derived and 95% non-human-derived E. coli respectively. These results indicate the validity of the usefulness of MAR indexing as a method of bacterial source tracking.

scholarly journals CONSTRUCTION, EXPRESSION AND PURIFICATION OF RECOMBINANT PRE-MATURE PEPTIDE OF PLANTARICIN F FROM Lactobacillus plantarum S34 IN Escherichia coli

2015 ◽  
Vol 16 (1) ◽  
pp. 31
Author(s):  
Kusdianawati Kusdianawati ◽  
Apon Zaenal Mustopa ◽  
Suharsono Suharsono ◽  
Bugi Ratno Budiarto ◽  
Fatimah Fatimah ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Plantarum ◽  
Proteolytic Enzymes ◽  
Leader Peptide ◽  
Human Consumption ◽  
Mature Peptide ◽  
Expression And Purification ◽  
Food Preservative ◽  
E Coli ◽  
Sds Page

Plantaricin is one of bacteriocins that have the potential to be used as food preservative. Plantaricin is safe for human consumption because it can be easily degraded by proteolytic enzymes. The objective of this study was to express and purify recombinant pre-mature peptide of plantaricin F from <em>Lactobacillus plantarum</em> S34 in <em>Escherichia coli</em>. Plantaricin gene-specific primer was used to obtain pln F structural gene amplicon from L. <em>plantarum</em> S34. This amplicon was cloned in pET32a vector and expressed in E. coli BL21 (DE3) pLysS. Pre-mature plantaricin F peptide was expressed as Histagged-fusion protein and separated by Co2+-chelating affinity chromatography. L. <em>plantarum</em> S34-derived pre-mature plantaricin F peptide fused with thioredoxin-(His)6tag had successfully been expressed in E. <em>coli</em> BL21 (DE3) pLysS using pET32a as an expression vector. The fused recombinant pln F as pre-mature state expressed had a molecular mass of +24 kDa, meanwhile the fused recombinant that contained only the leader peptide of pln F appeared as +20 kDa based on SDS-PAGE separations. The optimal production of fused recombinant pln F as soluble fraction was obtained when culture condition was added with 0.5 mM of IPTG and incubated at 22°C for 5 hours (OD~1). Furthermore, the expression of fused recombinant pln F as its pre-mature peptide pointed out that the pln F’s leader peptide could be proteolytically cleaved by a system in heterologous cells. Overall, heterologous pln F production as pre-mature peptide fused with thioredoxin-(His)6tag had been well established. From this research, we expect plantaricin F can be expressed and purified in E. coli.

scholarly journals Escherichia coli is not a suitable fecal indicator to assess water fecal contamination by otters

2017 ◽  
Vol 78 (1) ◽  
pp. 155-159 ◽  
Author(s):  
M. Oliveira ◽  
D. Freire ◽  
N. M. Pedroso
Keyword(s):  
Escherichia Coli ◽  
Fecal Contamination ◽  
Microbiological Quality ◽  
Aquatic Environments ◽  
Pathogenic Microorganisms ◽  
Fecal Indicator ◽  
Fecal Samples ◽  
E Coli ◽  
Paulo State

Abstract The detection of pathogenic microorganisms in aquatic environments is extremely relevant in terms of public health. As these laboratorial methodologies are usually difficult, expensive and time-consuming, they are frequently replaced by the assessment of fecal indicator bacteria, such as Escherichia coli. This study aimed to assess the presence of E. coli in fecal samples from Neotropical otters, to evaluate its potential as fecal indicator to be applied to the determination of water microbiological quality in areas where otters’ populations are high. Twenty-six otter fecal samples, collected in Alto Paranapanema river basin, São Paulo State, Brazil, were analyzed for the presence of E. coli, using conventional bacteriological methods. Only 8 scat samples (30%) were E. coli positive, indicating that this microorganism is not a suitable fecal indicator to assess water fecal contamination by Neotropical otters, and should not be used to infer the presence of otter related pathogens in waters.

scholarly journals Genome Sequence of a T4-like Phage, Escherichia Phage vB_EcoM-Sa45lw, Infecting Shiga Toxin-Producing Escherichia coli Strains

2019 ◽  
Vol 8 (32) ◽  
Author(s):  
Yen-Te Liao ◽  
Yujie Zhang ◽  
Alexandra Salvador ◽  
Vivian C. H. Wu
Keyword(s):  
Escherichia Coli ◽  
Surface Water ◽  
Genome Size ◽  
Shiga Toxin ◽  
Open Reading Frames ◽  
Content Type ◽  
E Coli ◽  
Double Stranded Dna ◽  
A Genome ◽  
Reading Frames

Escherichia phage vB_EcoM-Sa45lw, a new member of the T4-like phages, was isolated from surface water in a produce-growing area. The phage, containing double-stranded DNA with a genome size of 167,353 bp and 282 predicted open reading frames (ORFs), is able to infect generic Escherichia coli and Shiga toxin-producing E. coli O45 and O157 strains.

scholarly journals Genomewide Mutational Diversity in Escherichia coli Population Evolving in Prolonged Stationary Phase

mSphere ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Savita Chib ◽  
Farhan Ali ◽  
Aswin Sai Narain Seshasayee
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Stationary Phase ◽  
Phenotypic Diversity ◽  
Model System ◽  
Content Type ◽  
Neutral Drift ◽  
E Coli ◽  
Evolution By Natural Selection ◽  
Over Time

ABSTRACT Prolonged stationary phase in bacteria, contrary to its name, is highly dynamic, with extreme nutrient limitation as a predominant stress. Stationary-phase cultures adapt by rapidly selecting a mutation(s) that confers a growth advantage in stationary phase (GASP). The phenotypic diversity of starving E. coli populations has been studied in detail; however, only a few mutations that accumulate in prolonged stationary phase have been described. This study documented the spectrum of mutations appearing in Escherichia coli during 28 days of prolonged starvation. The genetic diversity of the population increases over time in stationary phase to an extent that cannot be explained by random, neutral drift. This suggests that prolonged stationary phase offers a great model system to study adaptive evolution by natural selection. Prolonged stationary phase is an approximation of natural environments presenting a range of stresses. Survival in prolonged stationary phase requires alternative metabolic pathways for survival. This study describes the repertoire of mutations accumulating in starving Escherichia coli populations in lysogeny broth. A wide range of mutations accumulates over the course of 1 month in stationary phase. Single nucleotide polymorphisms (SNPs) constitute 64% of all mutations. A majority of these mutations are nonsynonymous and are located at conserved loci. There is an increase in genetic diversity in the evolving populations over time. Computer simulations of evolution in stationary phase suggest that the maximum frequency of mutations observed in our experimental populations cannot be explained by neutral drift. Moreover, there is frequent genetic parallelism across populations, suggesting that these mutations are under positive selection. Finally, functional analysis of mutations suggests that regulatory mutations are frequent targets of selection. IMPORTANCE Prolonged stationary phase in bacteria, contrary to its name, is highly dynamic, with extreme nutrient limitation as a predominant stress. Stationary-phase cultures adapt by rapidly selecting a mutation(s) that confers a growth advantage in stationary phase (GASP). The phenotypic diversity of starving E. coli populations has been studied in detail; however, only a few mutations that accumulate in prolonged stationary phase have been described. This study documented the spectrum of mutations appearing in Escherichia coli during 28 days of prolonged starvation. The genetic diversity of the population increases over time in stationary phase to an extent that cannot be explained by random, neutral drift. This suggests that prolonged stationary phase offers a great model system to study adaptive evolution by natural selection.

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