scholarly journals Analysis of Global Transcriptional Profiles of Enterotoxigenic Escherichia coli Isolate E24377A

2012 ◽  
Vol 80 (3) ◽  
pp. 1232-1242 ◽  
Author(s):  
Jason W. Sahl ◽  
David A. Rasko
Keyword(s):  
Escherichia Coli ◽  
Bile Salts ◽  
Regulatory Networks ◽  
Luria Broth ◽  
Chemical Signals ◽  
Enterotoxigenic Escherichia Coli ◽  
Rna Seq ◽  
Content Type ◽  
E Coli ◽  
Colonization Factors

EnterotoxigenicEscherichia coli(ETEC) is an important pathogenic variant (pathovar) ofE. coliin developing countries from a human health perspective, causing significant morbidity and mortality. Previous studies have examined specific regulatory networks in ETEC, although little is known about the global effects of inter- and intrakingdom signaling on the expression of virulence and colonization factors in ETEC. In this study, anE. coli/Shigellapan-genome microarray, combined with quantitative reverse transcriptase PCR (qRT-PCR) and RNA sequencing (RNA-seq), was used to quantify the expression of ETEC virulence and colonization factors. Biologically relevant chemical signals were combined with ETEC isolate E24377A during growth in either Luria broth (LB) or Dulbecco's modified Eagle medium (DMEM), and transcription was examined during different phases of the growth cycle; chemical signals examined included glucose, bile salts, and preconditioned media fromE. coli/Shigellaisolates. The results demonstrate that the presence of bile salts, which are found in the intestine and thought to be bactericidal, upregulates the expression of many ETEC virulence factors, including heat-stable (estA) and heat-labile (eltA) enterotoxin genes. In contrast, the ETEC colonization factors CS1 and CS3 were downregulated in the presence of bile, consistent with findings in studies of other enteric pathogens. RNA-seq analysis demonstrated that one of the most differentially expressed genes in the presence of bile is a unique plasmid-encoded AraC-like transcriptional regulator (peaR); other previously unknown genetic elements were found as well. These results provide transcriptional targets and putative mechanisms that should help improve understanding of the global regulatory networks and virulence expression in this important human pathogen.

scholarly journals Elucidation of Regulatory Modes for Five Two-Component Systems in Escherichia coli Reveals Novel Relationships

mSystems ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Kumari Sonal Choudhary ◽  
Julia A. Kleinmanns ◽  
Katherine Decker ◽  
Anand V. Sastry ◽  
Ye Gao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Target Gene ◽  
Target Genes ◽  
Rna Seq ◽  
Content Type ◽  
E Coli ◽  
Component Systems ◽  
Two Component ◽  
Two Component Systems

ABSTRACT Escherichia coli uses two-component systems (TCSs) to respond to environmental signals. TCSs affect gene expression and are parts of E. coli’s global transcriptional regulatory network (TRN). Here, we identified the regulons of five TCSs in E. coli MG1655: BaeSR and CpxAR, which were stimulated by ethanol stress; KdpDE and PhoRB, induced by limiting potassium and phosphate, respectively; and ZraSR, stimulated by zinc. We analyzed RNA-seq data using independent component analysis (ICA). ChIP-exo data were used to validate condition-specific target gene binding sites. Based on these data, we do the following: (i) identify the target genes for each TCS; (ii) show how the target genes are transcribed in response to stimulus; and (iii) reveal novel relationships between TCSs, which indicate noncognate inducers for various response regulators, such as BaeR to iron starvation, CpxR to phosphate limitation, and PhoB and ZraR to cell envelope stress. Our understanding of the TRN in E. coli is thus notably expanded. IMPORTANCE E. coli is a common commensal microbe found in the human gut microenvironment; however, some strains cause diseases like diarrhea, urinary tract infections, and meningitis. E. coli’s two-component systems (TCSs) modulate target gene expression, especially related to virulence, pathogenesis, and antimicrobial peptides, in response to environmental stimuli. Thus, it is of utmost importance to understand the transcriptional regulation of TCSs to infer bacterial environmental adaptation and disease pathogenicity. Utilizing a combinatorial approach integrating RNA sequencing (RNA-seq), independent component analysis, chromatin immunoprecipitation coupled with exonuclease treatment (ChIP-exo), and data mining, we suggest five different modes of TCS transcriptional regulation. Our data further highlight noncognate inducers of TCSs, which emphasizes the cross-regulatory nature of TCSs in E. coli and suggests that TCSs may have a role beyond their cognate functionalities. In summary, these results can lead to an understanding of the metabolic capabilities of bacteria and correctly predict complex phenotype under diverse conditions, especially when further incorporated with genome-scale metabolic models.

Over-expression of major colonization factors of enterotoxigenic Escherichia coli, alone or together, on non-toxigenic E. coli bacteria

Vaccine ◽  
2010 ◽  
Vol 28 (43) ◽  
pp. 6977-6984 ◽  
Author(s):  
Joshua Tobias ◽  
Jan Holmgren ◽  
Maria Hellman ◽  
Erik Nygren ◽  
Michael Lebens ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enterotoxigenic Escherichia Coli ◽  
Over Expression ◽  
E Coli ◽  
Colonization Factors

scholarly journals TleA, a Tsh-Like Autotransporter Identified in a Human Enterotoxigenic Escherichia coli Strain

2015 ◽  
Vol 83 (5) ◽  
pp. 1893-1903 ◽  
Author(s):  
Daniela Gutiérrez ◽  
Mirka Pardo ◽  
David Montero ◽  
Angel Oñate ◽  
Mauricio J. Farfán ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Library ◽  
Coli Strain ◽  
Enterotoxigenic Escherichia Coli ◽  
Watery Diarrhea ◽  
Temperature Sensitive ◽  
Content Type ◽  
E Coli ◽  
Colonization Factor ◽  
Adhesion Level

EnterotoxigenicEscherichia coli(ETEC), a leading cause of acute diarrhea, colonizes the intestine by means of adhesins. However, 15 to 50% of clinical isolates are negative for known adhesins, making it difficult to identify antigens for broad-coverage vaccines. The ETEC strain 1766a, obtained from a child with watery diarrhea in Chile, harbors the colonization factor CS23 but is negative for other known adhesins. One clone, derived from an ETEC 1766a genomic library (clone G10), did not produce CS23 yet was capable of adhering to Caco-2 cells. The goal of this study was to identify the gene responsible for this capacity. Random transposon-based mutagenesis allowed the identification of a 4,110-bp gene that codes for a homologue of the temperature-sensitive hemagglutinin (Tsh) autotransporter described in avianE. colistrains (97% identity, 90% coverage) and that is called TleA (Tsh-like ETEC autotransporter) herein. An isogenic ETEC 1766a strain with atleAmutation showed an adhesion level similar to that of the wild-type strain, suggesting that the gene does not direct attachment to Caco-2 cells. However, expression oftleAconferred the capacity for adherence to nonadherentE. coliHB101. This effect coincided with the detection of TleA on the surface of nonpermeabilized bacteria, while, conversely, ETEC 1766a seems to secrete most of the produced autotransporter to the medium. On the other hand, TleA was capable of degrading bovine submaxillary mucin and leukocyte surface glycoproteins CD45 and P-selectin glycoprotein ligand 1 (PSGL-1). These results suggest that TleA promotes colonization of the intestinal epithelium and that it may modulate the host immune response.

scholarly journals Rapid Accumulation of Motility-Activating Mutations in Resting Liquid Culture ofEscherichia coli

2019 ◽  
Vol 201 (19) ◽  
Author(s):  
Darren J. Parker ◽  
Pınar Demetci ◽  
Gene-Wei Li
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Liquid Medium ◽  
Regulatory Networks ◽  
Gene Knockout ◽  
Single Gene ◽  
Point Mutations ◽  
Content Type ◽  
E Coli ◽  
Keio Collection

ABSTRACTExpression of motility genes is a potentially beneficial but costly process in bacteria. Interestingly, many isolate strains ofEscherichia colipossess motility genes but have lost the ability to activate them under conditions in which motility is advantageous, raising the question of how they respond to these situations. Through transcriptome profiling of strains in theE. colisingle-gene knockout Keio collection, we noticed drastic upregulation of motility genes in many of the deletion strains compared to levels in their weakly motile parent strain (BW25113). We show that this switch to a motile phenotype is not a direct consequence of the genes deleted but is instead due to a variety of secondary mutations that increase the expression of the major motility regulator, FlhDC. Importantly, we find that this switch can be reproduced by growing poorly motileE. colistrains in nonshaking liquid medium overnight but not in shaking liquid medium. Individual isolates after the nonshaking overnight incubations acquired distinct mutations upstream of theflhDCoperon, including different insertion sequence (IS) elements and, to a lesser extent, point mutations. The rapidity with which genetic changes sweep through the populations grown without shaking shows that poorly motile strains can quickly adapt to a motile lifestyle by genetic rewiring.IMPORTANCEThe ability to tune gene expression in times of need outside preordained regulatory networks is an essential evolutionary process that allows organisms to survive and compete. Here, we show that upon overnight incubation in liquid medium without shaking, populations of largely nonmotileEscherichia colibacteria can rapidly accumulate mutants that have constitutive motility. This effect contributes to widespread secondary mutations in the single-gene knockout library, the Keio collection. As a result, 49/71 (69%) of the Keio strains tested exhibited various degrees of motility, whereas their parental strain is poorly motile. These observations highlight the plasticity of gene expression even in the absence of preexisting regulatory programs and should raise awareness of procedures for handling laboratory strains ofE. coli.

scholarly journals An Escherichia coli Mutant That Makes Exceptionally Long Cells

2015 ◽  
Vol 197 (8) ◽  
pp. 1507-1514 ◽  
Author(s):  
Ziad W. El-Hajj ◽  
Elaine B. Newman
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Luria Broth ◽  
Small Cells ◽  
Content Type ◽  
E Coli ◽  
Coli Mutant ◽  
Rich Media ◽  
Shaped Cell ◽  
Cell Division Protein

ABSTRACTAlthoughEscherichia coliis a very small (1- to 2-μm) rod-shaped cell, here we describe anE. colimutant that forms enormously long cells in rich media such as Luria broth, as long indeed as 750 μm. Theseextremelyelongated (eel) cells are as long as the longest bacteria known and have no internal subdivisions. They are metabolically competent, elongate rapidly, synthesize DNA, and distribute cell contents along this length. They lack only the ability to divide. The concentration of the essential cell division protein FtsZ is reduced in these eel cells, and increasing this concentration restores division.IMPORTANCEEscherichia coliis usually a very small bacterium, 1 to 2 μm long. We have isolated a mutant that forms enormously long cells, 700 times longer than the usualE. colicell.E. colifilaments that form under other conditions usually die within a few hours, whereas our mutant is fully viable even when it reaches such lengths. This mutant provides a useful tool for the study of aspects ofE. coliphysiology that are difficult to investigate with small cells.

scholarly journals Lineage-Specific Distribution of Insertion Sequence Excision Enhancer in Enterotoxigenic Escherichia coli Isolated from Swine

2013 ◽  
Vol 80 (4) ◽  
pp. 1394-1402 ◽  
Author(s):  
Masahiro Kusumoto ◽  
Dai Fukamizu ◽  
Yoshitoshi Ogura ◽  
Eiji Yoshida ◽  
Fumiko Yamamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Bacterial Genome ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Genomic Deletions ◽  
Specific Distribution ◽  
Multiple Copies ◽  
Genomic Locations

ABSTRACTInsertion sequences (ISs) are the simplest transposable elements and are widely distributed in bacteria; however, they also play important roles in genome evolution. We recently identified a protein called IS excision enhancer (IEE) in enterohemorrhagicEscherichia coli(EHEC) O157. IEE promotes the excision of IS elements belonging to the IS3family, such as IS629, as well as several other families. IEE-mediated IS excision generates various genomic deletions that lead to the diversification of the bacterial genome. IEE has been found in a broad range of bacterial species; however, among sequencedE. colistrains, IEE is primarily found in EHEC isolates. In this study, we investigated non-EHEC pathogenicE. colistrains isolated from domestic animals and found that IEE is distributed in specific lineages of enterotoxigenicE. coli(ETEC) strains of serotypes O139 or O149 isolated from swine. Theieegene is located within integrative elements that are similar to SpLE1 of EHEC O157. Alliee-positive ETEC lineages also contained multiple copies of IS629, a preferred substrate of IEE, and their genomic locations varied significantly between strains, as observed in O157. These data suggest that IEE may have been transferred among EHEC and ETEC in swine via SpLE1 or SpLE1-like integrative elements. In addition, IS629is actively moving in the ETEC O139 and O149 genomes and, as in EHEC O157, is promoting the diversification of these genomes in combination with IEE.

Enterotoxigenic Escherichia coli Isolated from Foods in São Paulo, Brazil

1987 ◽  
Vol 50 (10) ◽  
pp. 832-834 ◽  
Author(s):  
BERNADETTE D. G. M. FRANCO ◽  
BEATRIZ E. C. GUTH ◽  
LUIZ R. TRABULSI
Keyword(s):  
Escherichia Coli ◽  
Food Samples ◽  
Sao Paulo ◽  
Enterotoxigenic Escherichia Coli ◽  
São Paulo ◽  
E Coli ◽  
Colonization Factors ◽  
The City

Incidence of enterotoxigenic Escherichia coli (ETEC) in foods usually consumed in the city of Sao Paulo, Brazil was determined. Raw and cooked foods of animal and vegetable origin were investigated. Enterotoxigenic strains were found in approximately 3.5% of food samples contaminated with E. coli. There was a great predominance of ETEC strains producing only LT enterotoxin. None of the isolated strains produced LT and ST simultaneously. Several serotypes were involved, and none of them was positive for colonization factors CFA-I and CFA-II. One ETEC showed resistance to some antibiotics but most were sensitive to the ones tested.

scholarly journals The Major Subunit, CfaB, of Colonization Factor Antigen I from Enterotoxigenic Escherichia coli Is a Glycosphingolipid Binding Protein

2006 ◽  
Vol 74 (6) ◽  
pp. 3488-3497 ◽  
Author(s):  
Lena Jansson ◽  
Joshua Tobias ◽  
Michael Lebens ◽  
Ann-Mari Svennerholm ◽  
Susann Teneberg
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Binding Capacity ◽  
Enterotoxigenic Escherichia Coli ◽  
E Coli ◽  
Colonization Factor ◽  
Mucosal Surfaces ◽  
Colonization Factors ◽  
Bacteria Adhesion ◽  
Colonization Factor Antigen I

ABSTRACT Bacterial adherence to mucosal surfaces is an important virulence trait of pathogenic bacteria. Adhesion of enterotoxigenic Escherichia coli (ETEC) to the intestine is mediated by a number of antigenically distinct colonization factors (CFs). One of the most common CFs is CFA/I. This has a fimbrial structure composed of a major repeating subunit, CfaB, and a single tip subunit, CfaE. The potential carbohydrate recognition by CFA/I was investigated by binding CFA/I-fimbriated bacteria and purified CFA/I fimbriae to a large number of variant glycosphingolipids separated on thin-layer chromatograms. For both fimbriated bacteria and purified fimbriae, specific interactions could be identified with a number of nonacid glycosphingolipids. These included glucosylceramide, lactosylceramide with phytosphingosine and/or hydroxy fatty acids, neolactotetraosylceramide, gangliotriaosylceramide, gangliotetraosylceramide, the H5 type 2 pentaglycosylceramide, the Lea-5 glycosphingolipid, the Lex-5 glycosphingolipid, and the Ley-6 glycosphingolipid. These glycosphingolipids were also recognized by recombinant E. coli expressing CFA/I in the absence of tip protein CfaE, as well as by purified fimbriae from the same strain. This demonstrates that the glycosphingolipid-binding capacity of CFA/I resides in the major CfaB subunit.

scholarly journals Allele Variants of Enterotoxigenic Escherichia coli Heat-Labile Toxin Are Globally Transmitted and Associated with Colonization Factors

2014 ◽  
Vol 197 (2) ◽  
pp. 392-403 ◽  
Author(s):  
Enrique Joffré ◽  
Astrid von Mentzer ◽  
Moataz Abd El Ghany ◽  
Numan Oezguen ◽  
Tor Savidge ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Fluid Secretion ◽  
Toxin Production ◽  
Amino Acid Sequences ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
Heat Labile ◽  
Virulence Potential ◽  
Colonization Factors

EnterotoxigenicEscherichia coli(ETEC) is a significant cause of morbidity and mortality in the developing world. ETEC-mediated diarrhea is orchestrated by heat-labile toxin (LT) and heat-stable toxins (STp and STh), acting in concert with a repertoire of more than 25 colonization factors (CFs). LT, the major virulence factor, induces fluid secretion after delivery of a monomeric ADP-ribosylase (LTA) and its pentameric carrier B subunit (LTB). A study of ETEC isolates from humans in Brazil reported the existence of natural LT variants. In the present study, analysis of predicted amino acid sequences showed that the LT amino acid polymorphisms are associated with a geographically and temporally diverse set of 192 clinical ETEC strains and identified 12 novel LT variants. Twenty distinct LT amino acid variants were observed in the globally distributed strains, and phylogenetic analysis showed these to be associated with different CF profiles. Notably, the most prevalent LT1 allele variants were correlated with major ETEC lineages expressing CS1 + CS3 or CS2 + CS3, and the most prevalent LT2 allele variants were correlated with major ETEC lineages expressing CS5 + CS6 or CFA/I. LTB allele variants generally exhibited more-stringent amino acid sequence conservation (2 substitutions identified) than LTA allele variants (22 substitutions identified). The functional impact of LT1 and LT2 polymorphisms on virulence was investigated by measuring total-toxin production, secretion, and stability using GM1–enzyme-linked immunosorbent assays (GM1-ELISA) andin silicoprotein modeling. Our data show that LT2 strains produce 5-fold more toxin than LT1 strains (P< 0.001), which may suggest greater virulence potential for this genetic variant. Our data suggest that functionally distinct LT-CF variants with increased fitness have persisted during the evolution of ETEC and have spread globally.

scholarly journals Emergence of a Multidrug-Resistant Shiga Toxin-Producing Enterotoxigenic Escherichia coli Lineage in Diseased Swine in Japan

2016 ◽  
Vol 54 (4) ◽  
pp. 1074-1081 ◽  
Author(s):  
Masahiro Kusumoto ◽  
Yuna Hikoda ◽  
Yuki Fujii ◽  
Misato Murata ◽  
Hirotsugu Miyoshi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Significant Risk ◽  
Multidrug Resistant ◽  
Limited Range ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Shigella Boydii ◽  
High Level

EnterotoxigenicEscherichia coli(ETEC) and Shiga toxin-producingE. coli(STEC) are important causes of diarrhea and edema disease in swine. The majority of swine-pathogenicE. colistrains belong to a limited range of O serogroups, including O8, O138, O139, O141, O147, O149, and O157, which are the most frequently reported strains worldwide. However, the circumstances of ETEC and STEC infections in Japan remain unknown; there have been few reports on the prevalence or characterization of swine-pathogenicE. coli. In the present study, we determined the O serogroups of 967E. coliisolates collected between 1991 and 2014 from diseased swine in Japan, and we found that O139, O149, O116, and OSB9 (O serogroup ofShigella boydiitype 9) were the predominant serogroups. We further analyzed these four O serogroups using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, and virulence factor profiling. Most of the O139 and O149 strains formed serogroup-specific PFGE clusters (clusters I and II, respectively), whereas the O116 and OSB9 strains were grouped together in the same cluster (cluster III). All of the cluster III strains belonged to a single sequence type (ST88) and carried genes encoding both enterotoxin and Shiga toxin. This PFGE cluster III/ST88 lineage exhibited a high level of multidrug resistance (to a median of 10 antimicrobials). Notably, these bacteria were resistant to fluoroquinolones. Thus, this lineage should be considered a significant risk to animal production due to the toxigenicity and antimicrobial resistance of these bacteria.

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