A subtractive hybridisation analysis of genomic differences between the uropathogenic E. coli strain 536 and the E. coli K-12 strain MG1655

Methods have been developed to study the intracellular Na and K concentrations in E. coli, strain K-12. These intracellular cation concentrations have been shown to be functions of the extracellular cation concentrations and the age of the bacterial culture. During the early logarithmic phase of growth, the intracellular K concentration greatly exceeds that of the external medium, whereas the intracellular Na concentration is lower than that of the growth medium. As the age of the culture increases, the intracellular K concentration falls and the intracellular Na concentration rises, changes which are related to the fall in the pH of the medium and to the accumulation of the products of bacterial metabolism. When stationary phase cells, which are rich in Na and poor in K, are resuspended in fresh growth medium, there is a rapid reaccumulation of K and extrusion of Na. These processes represent oppositely directed net ion movements against concentration gradients, and have been shown to be dependent upon the presence of an intact metabolic energy supply.

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The Transcriptional Antiterminator RfaH Represses Biofilm Formation in Escherichia coli

Journal of Bacteriology ◽

10.1128/jb.188.4.1316-1331.2006 ◽

2006 ◽

Vol 188 (4) ◽

pp. 1316-1331 ◽

Cited By ~ 67

Author(s):

Christophe Beloin ◽

Kai Michaelis ◽

Karin Lindner ◽

Paolo Landini ◽

Jörg Hacker ◽

...

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Wild Type Strain ◽

Wild Type ◽

Strain Mg1655 ◽

Upec Strain ◽

E Coli ◽

Initial Adhesion ◽

State Production ◽

K 12

ABSTRACT We investigated the influence of regulatory and pathogenicity island-associated factors (Hha, RpoS, LuxS, EvgA, RfaH, and tRNA5 Leu) on biofilm formation by uropathogenic Escherichia coli (UPEC) strain 536. Only inactivation of rfaH, which encodes a transcriptional antiterminator, resulted in increased initial adhesion and biofilm formation by E. coli 536. rfaH inactivation in nonpathogenic E. coli K-12 isolate MG1655 resulted in the same phenotype. Transcriptome analysis of wild-type strain 536 and an rfaH mutant of this strain revealed that deletion of rfaH correlated with increased expression of flu orthologs. flu encodes antigen 43 (Ag43), which mediates autoaggregation and biofilm formation. We confirmed that deletion of rfaH leads to increased levels of flu and flu-like transcripts in E. coli K-12 and UPEC. Supporting the hypothesis that RfaH represses biofilm formation through reduction of the Ag43 level, the increased-biofilm phenotype of E. coli MG1655rfaH was reversed upon inactivation of flu. Deletion of the two flu orthologs, however, did not modify the behavior of mutant 536rfaH. Our results demonstrate that the strong initial adhesion and biofilm formation capacities of strain MG1655rfaH are mediated by both increased steady-state production of Ag43 and likely increased Ag43 presentation due to null rfaH-dependent lipopolysaccharide depletion. Although the roles of rfaH in the biofilm phenotype are different in UPEC strain 536 and K-12 strain MG1655, this study shows that RfaH, in addition to affecting the expression of bacterial virulence factors, also negatively controls expression and surface presentation of Ag43 and possibly another Ag43-independent factor(s) that mediates cell-cell interactions and biofilm formation.

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The lipopolysaccharide of the mastitis isolate Escherichia coli strain 1303 comprises a novel O-antigen and the rare K-12 core type

Microbiology ◽

10.1099/mic.0.046912-0 ◽

2011 ◽

Vol 157 (6) ◽

pp. 1750-1760 ◽

Cited By ~ 13

Author(s):

Katarzyna A. Duda ◽

Buko Lindner ◽

Helmut Brade ◽

Andreas Leimbach ◽

Elżbieta Brzuszkiewicz ◽

...

Keyword(s):

Escherichia Coli ◽

Inner Core ◽

Bovine Mastitis ◽

Outer Core ◽

Coli Strain ◽

Core Oligosaccharide ◽

2D Nmr Spectroscopy ◽

E Coli ◽

O Antigen ◽

K 12

Mastitis represents one of the most significant health problems of dairy herds. The two major causative agents of this disease are Escherichia coli and Staphylococcus aureus. Of the first, its lipopolysaccharide (LPS) is thought to play a prominent role during infection. Here, we report the O-antigen (OPS, O-specific polysaccharide) structure of the LPS from bovine mastitis isolate E. coli 1303. The structure was determined utilizing chemical analyses, mass spectrometry, and 1D and 2D NMR spectroscopy methods. The O-repeating unit was characterized as -[→4)-β-d-Quip3NAc-(1→3)-α-l-Fucp2OAc-(1→4)-β-d-Galp-(1→3)-α-d-GalpNAc-(1→]- in which the O-acetyl substitution was non-stoichiometric. The nucleotide sequence of the O-antigen gene cluster of E. coli 1303 was also determined. This cluster, located between the gnd and galF genes, contains 13 putative open reading frames, most of which represent unknown nucleotide sequences that have not been described before. The O-antigen of E. coli 1303 was shown to substitute O-7 of the terminal ld-heptose of the K-12 core oligosaccharide. Interestingly, the non-OPS-substituted core oligosaccharide represented a truncated version of the K-12 outer core – namely terminal ld-heptose and glucose were missing; however, it possessed a third Kdo residue in the inner core. On the basis of structural and genetic data we show that the mastitis isolate E. coli 1303 represents a new serotype and possesses the K-12 core type, which is rather uncommon among human and bovine isolates.

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Characterization of the flexible genome complement of the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31)

Microbiology ◽

10.1099/mic.0.27469-0 ◽

2005 ◽

Vol 151 (2) ◽

pp. 385-398 ◽

Cited By ~ 33

Author(s):

Jana Hejnova ◽

Ulrich Dobrindt ◽

Radka Nemcova ◽

Christophe Rusniok ◽

Alojz Bomba ◽

...

Keyword(s):

Escherichia Coli ◽

Multiplex Pcr ◽

Gene Clusters ◽

Coli Strain ◽

Bac Clone ◽

Sequence Comparisons ◽

Multiple Sequence ◽

E Coli ◽

Gut Colonization ◽

K 12

Colonization by the commensal Escherichia coli strain A0 34/86 (O83 : K24 : H31) has proved to be safe and efficient in the prophylaxis and treatment of nosocomial infections and diarrhoea of preterm and newborn infants in Czech paediatric clinics over the past three decades. In searching for traits contributing to this beneficial effect related to the gut colonization capacity of the strain, the authors have analysed its genome by DNA–DNA hybridization to E. coli K-12 (MG1655) genomic DNA arrays and to ‘Pathoarrays’, as well as by multiplex PCR, bacterial artificial chromosome (BAC) library cloning and shotgun sequencing. Four hundred and ten E. coli K-12 ORFs were absent from A0 34/86, while 72 out of 456 genes associated with pathogenicity islands of E. coli and Shigella were also detected in E. coli A0 34/86. Furthermore, extraintestinal pathogenic E. coli-related genes involved in iron uptake and adhesion were detected by multiplex PCR, and genes encoding the HlyA and cytotoxic necrotizing factor toxins, together with 21 genes of the uropathogenic E. coli 536 pathogenicity island II, were identified by analysis of 2304 shotgun and 1344 BAC clone sequences of A0 34/86 DNA. Multiple sequence comparisons identified 31 kb of DNA specific for E. coli A0 34/86; some of the genes carried by this DNA may prove to be implicated in the colonization capacity of the strain, enabling it to outcompete pathogens. Among 100 examined BAC clones roughly covering the A0 34/86 genome, one reproducibly conferred on the laboratory strain DH10B an enhanced capacity to persist in the intestine of newborn piglets. Sequencing revealed that this BAC clone carried gene clusters encoding gluconate and mannonate metabolism, adhesion (fim), invasion (ibe) and restriction/modification functions. Hence, the genome of this clinically safe and highly efficient colonizer strain appears to harbour many ‘virulence-associated’ genes. These results highlight the thin line between bacterial ‘virulence’ and ‘fitness' or ‘colonization’ factors, and question the definition of enterobacterial virulence factors.

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Expression of fnr Is Constrained by an Upstream IS5 Insertion in Certain Escherichia coli K-12 Strains

Journal of Bacteriology ◽

10.1128/jb.187.8.2609-2617.2005 ◽

2005 ◽

Vol 187 (8) ◽

pp. 2609-2617 ◽

Cited By ~ 16

Author(s):

R. Gary Sawers

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Transcription Initiation ◽

Regulatory Region ◽

Initiation Site ◽

Strain Mg1655 ◽

Transcript Levels ◽

E Coli ◽

K 12 ◽

Strain Mc4100

ABSTRACT FNR is a global transcriptional regulator that controls anaerobic gene expression in Escherichia coli. Through the use of a number of approaches it was shown that fnr gene expression is reduced approximately three- to fourfold in E. coli strain MC4100 compared with the results seen with strain MG1655. This reduction in fnr expression is due to the insertion of IS5 (is5F) in the regulatory region of the gene at position −41 relative to the transcription initiation site. Transcription of the fnr gene nevertheless occurs from its own promoter in strain MC4100, but transcript levels are reduced approximately fourfold compared with those seen with strain MG1655. Remarkably, in strains bearing is5F the presence of Hfq prevents IS5-dependent transcriptional silencing of fnr expression. Thus, an hfq mutant of MC4100 is devoid of FNR protein and has the phenotype of an fnr mutant. In strain MG1655, or a derivative of MC4100 lacking is5F, mutation of hfq had no effect on fnr transcript levels. This finding indicates that IS5 mediates the effect of Hfq on fnr expression in MC4100. Western blot analysis revealed that cellular levels of FNR were reduced threefold in strain MC4100 compared with strain MG1655 results. A selection of FNR-dependent genes fused to lacZ were analyzed for the effects of reduced FNR levels on anaerobic gene expression. Expression of some operons, e.g., focA-pfl and fdnGHJI, was unaffected by reduction in the level of FNR, while the expression of other genes such as ndh and nikA was clearly affected.

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A SitABCD homologue from an avian pathogenic Escherichia coli strain mediates transport of iron and manganese and resistance to hydrogen peroxide

Microbiology ◽

10.1099/mic.0.28682-0 ◽

2006 ◽

Vol 152 (3) ◽

pp. 745-758 ◽

Cited By ~ 85

Author(s):

Mourad Sabri ◽

Simon Léveillé ◽

Charles M. Dozois

Keyword(s):

Escherichia Coli ◽

Hydrogen Peroxide ◽

Metal Ion ◽

Growth Promotion ◽

Coli Strain ◽

Transport Systems ◽

Virulence Plasmid ◽

E Coli ◽

K 12 ◽

Iron And Manganese

An operon encoding a member of the family of ATP-binding cassette (ABC) divalent metal ion transporters, homologous to Salmonella enterica SitABCD, has been identified in the avian pathogenic Escherichia coli (APEC) strain χ7122. The sitABCD genes were located on the virulence plasmid pAPEC-1, and were highly similar at the nucleotide level to the chromosomally encoded sitABCD genes present in Shigella spp. A cloned copy of sitABCD conferred increased growth upon a siderophore-deficient E. coli strain grown in nutrient broth supplemented with the chelator 2,2′-dipyridyl. Ion rescue demonstrated that Sit-mediated growth promotion of this strain was due to the transport of iron. SitABCD mediated increased transport of both iron and manganese as demonstrated by uptake of 55Fe, 59Fe or 54Mn in E. coli K-12 strains deficient for the transport of iron (aroB feoB) and manganese (mntH) respectively. Isotope uptake and transport inhibition studies showed that in the iron transport deficient strain, SitABCD demonstrated a greater affinity for iron than for manganese, and SitABCD-mediated transport was higher for ferrous iron, whereas in the manganese transport deficient strain, SitABCD demonstrated greater affinity for manganese than for iron. Introduction of the APEC sitABCD genes into an E. coli K-12 mntH mutant also conferred increased resistance to the bactericidal effects of hydrogen peroxide. APEC strain χ7122 derivatives lacking either a functional SitABCD or a functional MntH transport system were as resistant to hydrogen peroxide as the wild-type strain, whereas a Δsit ΔmntH double mutant was more sensitive to hydrogen peroxide. Overall, the results demonstrate that in E. coli SitABCD represents a manganese and iron transporter that, in combination with other ion transport systems, may contribute to acquisition of iron and manganese, and resistance to oxidative stress.

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Genomic data of an environmental Escherichia coli isolate shows high resemblance to E. coli K-12 reference strain MG1655.

Data in Brief ◽

10.1016/j.dib.2021.107586 ◽

2021 ◽

pp. 107586

Author(s):

Nicola Holden

Keyword(s):

Escherichia Coli ◽

Reference Strain ◽

Genomic Data ◽

Strain Mg1655 ◽

Coli Isolate ◽

E Coli ◽

K 12

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Cloning and expression of the beta-D-phosphogalactoside galactohydrolase gene of Lactobacillus casei in Escherichia coli K-12

Journal of Bacteriology ◽

10.1128/jb.152.3.1138-1146.1982 ◽

1982 ◽

Vol 152 (3) ◽

pp. 1138-1146

Author(s):

L J Lee ◽

J B Hansen ◽

E K Jagusztyn-Krynicka ◽

B M Chassy

Keyword(s):

Escherichia Coli ◽

Lactobacillus Casei ◽

Specific Activity ◽

Protein Product ◽

Coli Strain ◽

Cloning And Expression ◽

E Coli ◽

Lactose Metabolism ◽

Gene Coding ◽

K 12

Lactose metabolism in Lactobacillus casei 64H is associated with the presence of plasmid pLZ64. This plasmid determines both phosphoenolpyruvate-dependent phosphotransferase uptake of lactose and beta-D-phosphogalactoside galactohydrolase. A shotgun clone bank of chimeric plasmids containing restriction enzyme digest fragments of pLZ64 DNA was constructed in Escherichia coli K-12. One clone contained the gene coding for beta-D-phosphogalactoside galactohydrolase on a 7.9-kilobase PstI fragment cloned into the vector pBR322 in E. coli strain chi 1849. The beta-D-phosphogalactoside galactohydrolase enzyme isolated from E. coli showed no difference from that isolated from L. casei, and specific activity of beta-D-phosphogalactoside galactohydrolase was stimulated 1.8-fold in E. coli by growth in media containing beta-galactosides. A restriction map of the recombinant plasmid was compiled, and with that information, a series of subclones was constructed. From an analysis of the proteins produced by minicells prepared from transformant E. coli cells containing each of the recombinant subclone plasmids, it was found that the gene for the 56-kilodalton beta-D-phosphogalactoside galactohydrolase was transcribed from an L. casei-derived promoter. The gene for a second protein product (43 kilodaltons) was transcribed in the opposite direction, presumably under the control of a promoter in pBR322. The relationship of this second product to the lactose metabolism genes of L. casei is at present unknown.

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A Commensal Gone Bad: Complete Genome Sequence of the Prototypical Enterotoxigenic Escherichia coli Strain H10407

Journal of Bacteriology ◽

10.1128/jb.00710-10 ◽

2010 ◽

Vol 192 (21) ◽

pp. 5822-5831 ◽

Cited By ~ 121

Author(s):

Lisa C. Crossman ◽

Roy R. Chaudhuri ◽

Scott A. Beatson ◽

Timothy J. Wells ◽

Mickael Desvaux ◽

...

Keyword(s):

Escherichia Coli ◽

Genomic Sequence ◽

Epidemiological Data ◽

Coli Strain ◽

Enterotoxigenic Escherichia Coli ◽

E Coli ◽

Extraintestinal Disease ◽

K 12 ◽

Genetic Context ◽

Complete Genomic

ABSTRACT In most cases, Escherichia coli exists as a harmless commensal organism, but it may on occasion cause intestinal and/or extraintestinal disease. Enterotoxigenic E. coli (ETEC) is the predominant cause of E. coli-mediated diarrhea in the developing world and is responsible for a significant portion of pediatric deaths. In this study, we determined the complete genomic sequence of E. coli H10407, a prototypical strain of enterotoxigenic E. coli, which reproducibly elicits diarrhea in human volunteer studies. We performed genomic and phylogenetic comparisons with other E. coli strains, revealing that the chromosome is closely related to that of the nonpathogenic commensal strain E. coli HS and to those of the laboratory strains E. coli K-12 and C. Furthermore, these analyses demonstrated that there were no chromosomally encoded factors unique to any sequenced ETEC strains. Comparison of the E. coli H10407 plasmids with those from several ETEC strains revealed that the plasmids had a mosaic structure but that several loci were conserved among ETEC strains. This study provides a genetic context for the vast amount of experimental and epidemiological data that have been published.

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S-Fimbria-Encoding Determinant sfaI Is Located on Pathogenicity Island III536 of UropathogenicEscherichia coli Strain 536

Infection and Immunity ◽

10.1128/iai.69.7.4248-4256.2001 ◽

2001 ◽

Vol 69 (7) ◽

pp. 4248-4256 ◽

Cited By ~ 74

Author(s):

Ulrich Dobrindt ◽

Gabriele Blum-Oehler ◽

Thomas Hartsch ◽

Gerhard Gottschalk ◽

Eliora Z. Ron ◽

...

Keyword(s):

Insertion Sequence ◽

Pathogenicity Island ◽

Coli Strain ◽

E Coli ◽

Sequence Elements ◽

Fimbrial Adhesins ◽

Colicin V ◽

K 12 ◽

Insertion Sequence Elements ◽

Fimbrial Adhesin

ABSTRACT The sfa I determinant encoding the S-fimbrial adhesin of uropathogenic Escherichia colistrains was found to be located on a pathogenicity island of uropathogenic E. coli strain 536. This pathogenicity island, designated PAI III536, is located at 5.6 min of theE. coli chromosome and covers a region of at least 37 kb between the tRNA locus thrW and yagU. As far as it has been determined, PAI III536 also contains genes which code for components of a putative enterochelin siderophore system of E. coli and Salmonella spp. as well as for colicin V immunity. Several intact or nonfunctional mobility genes of bacteriophages and insertion sequence elements such as transposases and integrases are present on PAI III536. The presence of known PAI III536 sequences has been investigated in several wild-type E. coli isolates. The results demonstrate that the determinants of the members of the S-family of fimbrial adhesins may be located on a common pathogenicity island which, in E. coli strain 536, replaces a 40-kb DNA region which represents anE. coli K-12-specific genomic island.

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