scholarly journals Transduction, restriction and recombination patterns in Escherichia coli.

Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 35-43
Author(s):  
M McKane ◽  
R Milkman
Keyword(s):  
Escherichia Coli ◽  
Coli Strain ◽  
Chromosomal Dna ◽  
Bacteriophage P1 ◽  
E Coli ◽  
Sequence Patterns ◽  
Single Marker ◽  
Different Strains ◽  
Restriction Modification ◽  
Restriction Modification Systems

Abstract Chromosomal DNA from several Escherichia coli reference (ECOR) strains was transduced by bacteriophage P1 into E. coli strain K12 W3110 trpA33. Recombination patterns of the transductants were determined by restriction fragment length polymorphism over a 40-kb region centering on a single marker (trpA+) in the tryptophan operon. These experiments demonstrate that transduction between different strains of E. coli can result in recombinational replacements that are small in comparison to the entrant molecule (replacements average 8-14 kb, whereas P1 packages approximately 100 kb) often in a series of discrete segments. The transduction patterns generated resemble the natural mosaic sequence patterns of the ECOR strains described in previous work. Extensive polymorphisms in the restriction-modification systems of the ECOR strains are a possible explanation for the sequence patterns in nature. To test this possibility two transductants were back-transduced into strain K12 W3110 trpA33. The resulting patterns were strikingly different from the original transductions. The size of the replacements was greater, and no multiple replacements were observed, suggesting a role for restriction-modification systems in the transduction patterns and perhaps for the mosaic sequence patterns in nature.

scholarly journals Methylation by multiple type I restriction modification systems avoids influencing gene regulation in uropathogenic Escherichia coli

2021 ◽  
Author(s):  
Kurosh S Mehershahi ◽  
Swaine Chen
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Dna Methylation ◽  
Gene Regulation ◽  
Detectable Effect ◽  
Epigenetic Mark ◽  
Type I ◽  
E Coli ◽  
Restriction Modification ◽  
Restriction Modification Systems

DNA methylation is a common epigenetic mark that influences transcriptional regulation, and therefore cellular phenotype, across all domains of life, extending also to bacterial virulence. Both orphan methyltransferases and those from restriction modification systems (RMSs) have been co-opted to regulate virulence epigenetically in many bacteria. However, the potential regulatory role of DNA methylation mediated by archetypal Type I systems in Escherichia coli has never been studied. We demonstrated that removal of DNA methylated mediated by three different Escherichia coli Type I RMSs in three distinct E. coli strains had no detectable effect on gene expression or growth in a screen of 1190 conditions. Additionally, deletion of the Type I RMS EcoUTI in UTI89, a prototypical cystitis strain of E. coli , which led to loss of methylation at >750 sites across the genome, had no detectable effect on virulence in a murine model of ascending urinary tract infection (UTI). Finally, introduction of two heterologous Type I RMSs into UTI89 also resulted in no detectable change in gene expression or growth phenotypes. These results stand in sharp contrast with many reports of RMSs regulating gene expression in other bacteria, leading us to propose the concept of “regulation avoidance” for these E. coli Type I RMSs. We hypothesize that regulation avoidance is a consequence of evolutionary adaptation of both the RMSs and the E. coli genome. Our results provide a clear and (currently) rare example of regulation avoidance for Type I RMSs in multiple strains of E. coli , further study of which may provide deeper insights into the evolution of gene regulation and horizontal gene transfer.

scholarly journals Molecular Evolution of the Escherichia coli Chromosome. V. Recombination Patterns Among Strains of Diverse Origin

Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 539-554 ◽  
Author(s):  
Roger Milkman ◽  
Elisabeth A Raleigh ◽  
Melissa McKane ◽  
Diane Cryderman ◽  
Patricia Bilodeau ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Evolution ◽  
Parental Strain ◽  
Activity Analysis ◽  
Exonuclease Activity ◽  
Recombinant Chromosome ◽  
E Coli ◽  
Diverse Origin ◽  
Restriction Modification ◽  
Restriction Modification Systems

Abstract Incorporation patterns of donor DNA into recipient chromosomes following transduction or conjugation have been studied in the progeny of a variety of Escherichia coli crosses in which donor and recipient nucleotide sequences differ by 1-3%. Series of contiguous or variously spaced PCR fragments have been amplified from each recombinant chromosome and digested with a commercial restriction endonuclease previously shown to distinguish the respective parents in a given fragment. We conclude that entering donor DNA fragments are frequently abridged (cut and shortened) before incorporation, the cutting being due to restriction systems, and the shortening presumably due to exonuclease activity. Analysis of several backcrosses confirms, and extends to conjugation, the importance of restriction in E. coli recombination in nature. The transmission patterns in conjugation are similar to those of transduction, but (as expected) on a much larger scale. Asymmetric results of reciprocal crosses imply that mismatch frequency is not a major factor. Marked differences among the results of simple crosses according to parental strain combinations are consistent with observations that E. coli strains in nature vary dramatically in their restriction-modification systems.

scholarly journals Evidence of Horizontal Transfer of theEcoO109I Restriction-Modification Gene to Escherichia coli Chromosomal DNA

1999 ◽  
Vol 181 (21) ◽  
pp. 6822-6827 ◽  
Author(s):  
Keiko Kita ◽  
Junko Tsuda ◽  
Toshinobu Kato ◽  
Kenji Okamoto ◽  
Hideshi Yanase ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Horizontal Transfer ◽  
Attachment Site ◽  
Chromosomal Dna ◽  
E Coli ◽  
Bacteriophage P4 ◽  
Dna Fragment ◽  
Stable Maintenance ◽  
K 12 ◽  
Restriction Modification

ABSTRACT A DNA fragment carrying the genes coding for EcoO109I endonuclease and EcoO109I methylase, which recognize the nucleotide sequence 5′-(A/G)GGNCC(C/T)-3′, was cloned from the chromosomal DNA of Escherichia coli H709c. TheEcoO109I restriction-modification (R-M) system was found to be inserted between the int and psu genes from satellite bacteriophage P4, which were lysogenized in the chromosome at the P4 phage attachment site of the corresponding leuX gene observed in E. coli K-12 chromosomal DNA. Thesid gene of the prophage was inactivated by insertion of one copy of IS21. These findings may shed light on the horizontal transfer and stable maintenance of the R-M system.

scholarly journals New indicator Escherichia coli strain for rapid and accurate detection of supF mutations

2020 ◽  
Vol 42 (1) ◽  
Author(s):  
Ruriko Fukushima ◽  
Tetsuya Suzuki ◽  
Hiroyuki Kamiya
Keyword(s):  
Escherichia Coli ◽  
Mammalian Cells ◽  
Indicator Strain ◽  
Coli Strain ◽  
Chromosomal Dna ◽  
Amber Mutation ◽  
E Coli ◽  
Accurate Detection ◽  
Mutation Spectra ◽  
Forward Mutation

Abstract Background The supF gene of Escherichia coli is useful for forward mutation analysis in bacterial and mammalian cells used in mutagenesis and DNA repair studies. Indicator E. coli strains, such as KS40/pOF105, have been used to analyze supF mutations. However, KS40/pOF105 is not enough to select supF mutants on nutrient-rich agar plates. Therefore, in this study, a new indicator E. coli strain for rapid and accurate detection of supF mutations was developed. Results The gyrA and rpsL genes with an amber mutation were integrated into the chromosomal DNA of E. coli KS40 to produce a new indicator strain, RF01. RF01 cells transformed by the wild-type supF gene were sensitive to nalidixic acid and streptomycin on LB agar plates. supF mutant frequencies and mutation spectra in RF01 were similar to those in KS40/pOF105. In addition, some mutations in supF were only detected in RF01. Conclusion RF01 is a new and useful indicator E. coli strain for analyzing supF mutations.

scholarly journals Temporal Appraisal and Molecular Characterization of Escherichia coli from Oyun River, Kwara State, Nigeria

2020 ◽  
pp. 56-63
Author(s):  
Olatunji Matthew Kolawole ◽  
Oluwasanmi Anuoluwapo Adeyemi
Keyword(s):  
Escherichia Coli ◽  
Molecular Characterization ◽  
Bacterial Load ◽  
Disease Outbreaks ◽  
Coli Strain ◽  
Microbial Count ◽  
Mean Values ◽  
E Coli ◽  
Risk Variants ◽  
Different Strains

Introduction: Escherichia coli, an indicator of feacal contamination has been proven to be the cause of several disease outbreaks in countries and continents around the world. Aim: To determine the genotypic variants of Escherichia coli present in Oyun River and provide information regarding the high-risk variants of E. coli in Oyun River. Study Design: The study cuts across the two seasons of Nigeria’s tropical climate weather, being the peak of the Harmattan season and the onset of the Rainy season. Three sampling sites (Jimba Oja; Unilorin Dam and Oyun in Ilorin, Kwara State) along the River course were examined for three months (February – April). Methodology: Heterotrophic counts, coli form counts and molecular characterization via PCR   using 16 sRNA primers, of water samples were done using standard microbiological and molecular methods. Results: Bacteriological results showed monthly mean values of microbial counts, ranged from 23.5 x 106 – 45.17 x 106 cfu/mL and total coli form count ranged from 53 cfu/100 mL to 256 cfu/100 mLs, both of which exceed the WHO standards of 100 cfu/mL for total microbial count and <1 cfu/100 mLs for total coliforms. A total of forty-eight coliforms were isolated, thirty two of which were Escherichia coli. Sequencing and BLAST analysis of eleven of the isolates using NCBI’s online database revealed five different strains. They include: Escherichia coli FAP1 genome (9.1%); Escherichia coli strain ST2747 (54.5%); Escherichia coli strain EADK4 (9.1%); Escherichia coli strain ST540 (18.2%) and Escherichia coli strain NCM3722 (9.1%). Correlation of results with previous studies showed that most of the strains identified were pathogenic. The E. coli strains isolated, coupled with the bacterial load, coliform count and some physicochemical parameters of Oyun River makes it unsafe for public consumption if not treated. Efforts therefore should be made to treat the water before use, while making frantic efforts to prevent further contamination of Oyun River.

Transport of escherichia coli through soil to groundwater traced by randomly amplified polymorphic DNA (RAPD)

1997 ◽  
Vol 35 (11-12) ◽  
pp. 351-357 ◽  
Author(s):  
R. Rothmaier ◽  
A. Weidenmann ◽  
K. Botzenhart
Keyword(s):  
Negative Impact ◽  
Random Amplified Polymorphic Dna ◽  
Coli Strain ◽  
Soil Samples ◽  
Test Field ◽  
Liquid Manure ◽  
E Coli ◽  
Rapd Pattern ◽  
Geological Situation ◽  
Different Strains

Isolates (50) of E. coli obtained from liquid manure (20 bovine, 20 porcine) were genotyped using random amplified polymorphic DNA (RAPD). Typing revealed 9 and 14 different strains in bovine and porcine liquid manure respectively with no strains in common. One porcine strain, showing a simple RAPD pattern, was subcultured and spread on a test field (1.5l/m2 at 1010 cfu/l) in a drinking water protection zone with loamy to sandy sediments in the Donauried area, Baden-Wurttemberg. Soil samples and groundwaters were collected at monthly intervals October 1994 – June 1995 during which 114 E. coli isolates were recovered. The first occurrence and maximum concentration of E. coli in soil samples taken from more than 20cm depth was in January 1995, declining rapidly with depth and time. All isolates from soil and only one from groundwater showed the RAPD pattern of the spread E. coli strain. The results could not demonstrate a severe negative impact of the spreading of liquid manure on the bacteriological quality of the groundwater in the given geological situation. The distinct strain patterns found in different kinds of liquid manure suggest that genotyping of E. coli by RAPD may be an adequate tool for tracing sources of faecal contamination.

scholarly journals Regulation of Expression of the TIR-Containing Protein C Gene of the Uropathogenic Escherichia coli Strain CFT073

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 549
Author(s):  
Julia Ittensohn ◽  
Jacqueline Hemberger ◽  
Hannah Griffiths ◽  
Maren Keller ◽  
Simone Albrecht ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein C ◽  
Interleukin 1 ◽  
Coli Strain ◽  
Uropathogenic Escherichia Coli ◽  
Reporter Construct ◽  
Regulation Of Expression ◽  
E Coli ◽  
Strain Cft073 ◽  
Myeloid Differentiation Factor

The uropathogenic Escherichia coli strain CFT073 causes kidney abscesses in mice Toll/interleukin-1 receptor domain-containing protein C (TcpC) dependently and the corresponding gene is present in around 40% of E. coli isolates of pyelonephritis patients. It impairs the Toll-like receptor (TLR) signaling chain and the NACHT leucin-rich repeat PYD protein 3 inflammasome (NLRP3) by binding to TLR4 and myeloid differentiation factor 88 as well as to NLRP3 and caspase-1, respectively. Overexpression of the tcpC gene stopped replication of CFT073. Overexpression of several tcpC-truncation constructs revealed a transmembrane region, while its TIR domain induced filamentous bacteria. Based on these observations, we hypothesized that tcpC expression is presumably tightly controlled. We tested two putative promoters designated P1 and P2 located at 5′ of the gene c2397 and 5′ of the tcpC gene (c2398), respectively, which may form an operon. High pH and increasing glucose concentrations stimulated a P2 reporter construct that was considerably stronger than a P1 reporter construct, while increasing FeSO4 concentrations suppressed their activity. Human urine activated P2, demonstrating that tcpC might be induced in the urinary tract of infected patients. We conclude that P2, consisting of a 240 bp region 5′ of the tcpC gene, represents the major regulator of tcpC expression.

Polyester Cloth–Based Hybridization Array System for Identification of Enterohemorrhagic Escherichia coli Serogroups O26, O45, O103, O111, O121, O145, and O157

2012 ◽  
Vol 75 (9) ◽  
pp. 1691-1697 ◽  
Author(s):  
BURTON W. BLAIS ◽  
MARTINE GAUTHIER ◽  
MYLÈNE DESCHÊNES ◽  
GEORGE HUSZCZYNSKI
Keyword(s):  
Escherichia Coli ◽  
Marker Gene ◽  
Enterohemorrhagic Escherichia Coli ◽  
Oligonucleotide Probes ◽  
E Coli ◽  
Polyester Cloth ◽  
Gene Profiles ◽  
Pcr Products ◽  
Different Strains ◽  
Immunoenzymatic Assay

A cloth-based hybridization array system (CHAS) was developed for the identification of foodborne colony isolates of seven priority enterohemorrhagic Escherichia coli (EHEC-7) serogroups targeted by U.S. food inspection programs. Gene sequences associated with intimin; Shiga-like toxins 1 and 2; and the antigenic markers O26, O45, O103, O111, O121, O145, and O157 were amplified in a multiplex PCR incorporating a digoxigenin label, and detected by hybridization of the PCR products with an array of specific oligonucleotide probes immobilized on a polyester cloth support, with subsequent immunoenzymatic assay of the captured amplicons. The EHEC-7 CHAS exhibited 100% inclusivity and 100% exclusivity characteristics with respect to detection of the various markers among 89 different E. coli strains, with various marker gene profiles and 15 different strains of non–E. coli bacteria.

scholarly journals Genetic Organization of the Vibrio harveyi dnaA Gene Region and Analysis of the Function of the V. harveyi DnaA Protein in Escherichia coli

2002 ◽  
Vol 184 (9) ◽  
pp. 2533-2538 ◽  
Author(s):  
Dvora Berenstein ◽  
Kirsten Olesen ◽  
Christian Speck ◽  
Ole Skovgaard
Keyword(s):  
Escherichia Coli ◽  
Promoter Region ◽  
Vibrio Harveyi ◽  
Gene Region ◽  
Chromosomal Dna ◽  
Dnaa Gene ◽  
E Coli ◽  
Dnaa Protein ◽  
Dam Methylase ◽  
And Function

ABSTRACT The Vibrionaceae family is distantly related to Enterobacteriaceae within the group of bacteria possessing the Dam methylase system. We have cloned, sequenced, and analyzed the dnaA gene region of Vibrio harveyi and found that although the organization of the V. harveyi dnaA region differs from that of Escherichia coli, the expression of both genes is autoregulated and ATP-DnaA binds cooperatively to ATP-DnaA boxes in the dnaA promoter region. The DnaA proteins of V. harveyi and E. coli are interchangeable and function nearly identically in controlling dnaA transcription and the initiation of chromosomal DNA replication despite the evolutionary distance between these bacteria.

scholarly journals Transcriptomic Analysis of Shiga Toxin-Producing Escherichia coli during Initial Contact with Cattle Colonic Explants

2020 ◽  
Vol 8 (11) ◽  
pp. 1662
Author(s):  
Zachary R. Stromberg ◽  
Rick E. Masonbrink ◽  
Melha Mellata
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Bacterial Colonization ◽  
Coli Strain ◽  
Fold Change ◽  
Initial Contact ◽  
Lon Protease ◽  
E Coli ◽  
Log2 Fold Change ◽  
Colonization Factors

Foodborne pathogens are a public health threat globally. Shiga toxin-producing Escherichia coli (STEC), particularly O26, O111, and O157 STEC, are often associated with foodborne illness in humans. To create effective preharvest interventions, it is critical to understand which factors STEC strains use to colonize the gastrointestinal tract of cattle, which serves as the reservoir for these pathogens. Several colonization factors are known, but little is understood about initial STEC colonization factors. Our objective was to identify these factors via contrasting gene expression between nonpathogenic E. coli and STEC. Colonic explants were inoculated with nonpathogenic E. coli strain MG1655 or STEC strains (O26, O111, or O157), bacterial colonization levels were determined, and RNA was isolated and sequenced. STEC strains adhered to colonic explants at numerically but not significantly higher levels compared to MG1655. After incubation with colonic explants, flagellin (fliC) was upregulated (log2 fold-change = 4.0, p < 0.0001) in O157 STEC, and collectively, Lon protease (lon) was upregulated (log2 fold-change = 3.6, p = 0.0009) in STEC strains compared to MG1655. These results demonstrate that H7 flagellum and Lon protease may play roles in early colonization and could be potential targets to reduce colonization in cattle.

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