Capsules of Escherichia coli, expression and biological significance

1992 ◽  
Vol 38 (7) ◽  
pp. 705-710 ◽  
Author(s):  
Klaus Jann ◽  
Barbara Jann
Keyword(s):  
Escherichia Coli ◽  
Host Defense ◽  
Pathogenic Bacteria ◽  
Biological Significance ◽  
Surface Expression ◽  
Capsular Polysaccharides ◽  
Virulence Determinants ◽  
E Coli ◽  
Group I ◽  
Group Ii

Escherichia coli may cause intestinal or extraintestinal infections. Generally, extraintestinal E. coli are encapsulated. The capsules are important virulence determinants, which enable the pathogenic bacteria to evade or counteract the unspecific host defense during the early (preimmune) phase of infection. They interfere with the action of complement and phagocytes. This effect is generally transient and overcome by capsule-specific antibodies in the immune phase of the host defense. In some cases, capsules are not or only poorly immunogenic, as a result of structural relationship or identity with host material. Strains with such capsules (e.g., K1 or K5) are very virulent. Bacterial capsules consist of acidic polysaccharides, which are made up from oligosaccharide repeating units. The capsules of E. coli are divided into two groups, which differ in chemistry, biochemistry, and genetic organization. All capsular polysaccharides are chromosomally determined: those of group I close to his and those of group II close to serA. The biosynthesis and surface expression have been extensively studied with representatives of group II capsular polysaccharides. It could be shown that their biosynthesis is directed from a gene block that determines the synthesis of the polysaccharide, its translocation across the cytoplasmic membrane, as well as its surface expression in a coordinate process. The chemical nature of group II capsular polysaccharides, as well as the mechanism(s) of their biosynthesis and expression, is presented. Key words: Escherichia coli, capsular polysaccharides, structure, genetics, biology.

scholarly journals PENGARUH PEMBERIAN Lactobacillus TERHADAP GAMBARAN MIKROSKOPIS MUKOSA USUS HALUS TIKUS WISTAR (Rattus norvegicus) YANG DIINFEKSI DENGAN Escherichia coli

2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Steviany Towoliu
Keyword(s):  
Escherichia Coli ◽  
Wistar Rats ◽  
Pathogenic Bacteria ◽  
Control Group ◽  
Group Iii ◽  
Treatment Groups ◽  
E Coli ◽  
Group 4 ◽  
Group I ◽  
Microscopic Features

Abstract: E. coli is part of the normal flora of the human and animal intestine and is commonly non pathogenic. However, one of the serotypes of this bacteria, which is enteropathogenic E. coli (EPEC), can cause primary infection on the intestine such diarrhea.  The growth of pathogenic bacteria in diarrheal patients can be inhibited by Lactobacillus.  Lactobacillus can function as probiotic which can affect the immune system of the digestive canals.  In addition, Lactobacillus also produce mucus  which can act as barrier to the pathogens.  The objective of this study was to reveal the effects of the administration of Lactobacillus on the microscopic features of the mucosa of the intestine of wistar rats infected by Escherichia coli.  This study was a laboratory experimental research employing 16 wistar rats divided into the control group (4 rats) and three treatment groups (12 rats) consisting of 4 rats each.  Results showed that; in group I the histological features were normal, in group II part of the epithelium of the mucosa showed erosion, dilatation of the capillary vessels, and many lymphosites were observed, in group III the epithelium of the mucosa was intact and the number of lymphosites was liitle, and in group IV the surface of the epithelium was intact, the presence of cell regeneration indicated by the increase number of goblet cells and a small number of  lymphocyes. Conclusions: The administration of after infection by E. coli has benefial effects indicated by the improvement of epithelial cells and the absence of denudation of the epithelium of the intestine. Keywords: E.coli, Lactobacillus, intestinal mucosa.   Abstrak: E.coli merupakan flora normal usus halus manusia dan hewan umumnya tidak menyebabkan penyakit.  Namun salah satu serotipe E.coli yaitu E.coli Enteropatogenik (EPEK) bersifat patogen dan dapat menyebabkan infeksi primer pada usus misalnya diare.  Pertumbuhan bakteri patogen pada pasien diare dapat dihambat oleh Lactobacillus. Lactobacillus merupakan probiotik yang akan mempengaruhi sistem imun saluran cerna serta memproduksi mukus yang berfungsi sebagai penghalang saluran cerna terhadap bakteri patogen.  Penelitian ini bertujuan untuk melihat efek pemberian Lactobacillus terhadap gambaran mikroskopis mukosa usus halus tikus wistar yang diinfeksi dengan Escherichia coli.  Penelitian ini merupakan penelitian eksperimental laboratorik.  Subjek penelitian terdiri dari 16 ekor tikur wistar yang dibagi dalam kelompok kontrol (4 ekor) dan kelompok  perlakuan (12 ekor) dibagi dalam 3 kelompok masing-masing 4 ekor.  Hasil penelitian kelompok I dengan gambaran histologik jaringan usus normal, kelompok II sebagian epitel mukosa usus halus terlihat erosi,  ada pelebaran pembuluh darah kapiler, dan banyak limfosit, kelompok III dengan permukaan epitel mukosa yang utuh dan jumlah limfosit sedikit, dan kelompok IV dengan permukaan epitel yang utuh, adanya regenerasi sel ditandai dengan bertambahnya sel goblet, dan sedikit limfosit.  Simpulan: Pemberian Lactobacillus setelah diberikan E.coli memberi efek yang baik berupa perbaikan sel epitel permukaan dan tidak terlihat denudasi epitel permukaan usus halus. Kata Kunci: E.coli, Lactobacillus, mukosa usus halus.

scholarly journals Role of Host Xanthine Oxidase in Infection Due to Enteropathogenic and Shiga-Toxigenic Escherichia coli

2013 ◽  
Vol 81 (4) ◽  
pp. 1129-1139 ◽  
Author(s):  
John K. Crane ◽  
Tonniele M. Naeher ◽  
Jacqueline E. Broome ◽  
Edgar C. Boedeker
Keyword(s):  
Escherichia Coli ◽  
Xanthine Oxidase ◽  
Host Defense ◽  
Pathogenic Bacteria ◽  
Intestinal Cell ◽  
Intestinal Loop ◽  
Loop Model ◽  
Content Type ◽  
E Coli

ABSTRACTXanthine oxidase (XO), also known as xanthine oxidoreductase, has long been considered an important host defense molecule in the intestine and in breastfed infants. Here, we present evidence that XO is released from and active in intestinal tissues and fluids in response to infection with enteropathogenicEscherichia coli(EPEC) and Shiga-toxigenicE. coli(STEC), also known as enterohemorrhagicE. coli(EHEC). XO is released into intestinal fluids in EPEC and STEC infection in a rabbit animal model. XO activity results in the generation of surprisingly high concentrations of uric acid in both cultured cell and animal models of infection. Hydrogen peroxide (H2O2) generated by XO activity triggered a chloride secretory response in intestinal cell monolayers within minutes but decreased transepithelial electrical resistance at 6 to 22 h. H2O2generated by XO activity was effective at killing laboratory strains ofE. coli, commensal microbiotas, and anaerobes, but wild-type EPEC and STEC strains were 100 to 1,000 times more resistant to killing or growth inhibition by this pathway. Instead of killing pathogenic bacteria, physiologic concentrations of XO increased virulence by inducing the production of Shiga toxins from STEC strains.In vivo, exogenous XO plus the substrate hypoxanthine did not protect and instead worsened the outcome of STEC infection in the rabbit ligated intestinal loop model of infection. XO released during EPEC and STEC infection may serve as a virulence-inducing signal to the pathogen and not solely as a protective host defense.

scholarly journals Functional Analysis of Conserved Gene Products Involved in Assembly of Escherichia coli Capsules and Exopolysaccharides: Evidence for Molecular Recognition between Wza and Wzc for Colanic Acid Biosynthesis

2005 ◽  
Vol 187 (15) ◽  
pp. 5470-5481 ◽  
Author(s):  
Anne N. Reid ◽  
Chris Whitfield
Keyword(s):  
Escherichia Coli ◽  
Chimeric Protein ◽  
Surface Expression ◽  
Capsular Polysaccharides ◽  
E Coli ◽  
Colanic Acid ◽  
Periplasmic Domain ◽  
Conserved Gene ◽  
K 12 ◽  
Group 1

ABSTRACT Group 1 capsular polysaccharides (CPSs) of Escherichia coli and some loosely cell-associated exopolysaccharides (EPSs), such as colanic acid, are assembled by a Wzy-dependent polymerization system. In this biosynthesis pathway, Wza, Wzb, and Wzc homologues are required for surface expression of wild-type CPS or EPS. Multimeric complexes of Wza in the outer membrane are believed to provide a channel for polymer export; Wzc is an inner membrane tyrosine autokinase and Wzb is its cognate phosphatase. This study was performed to determine whether the Wza, Wzb, and Wzc proteins for colanic acid expression in E. coli K-12 could function in the E. coli K30 prototype group 1 capsule system. When expressed together, colanic acid Wza, Wzb, and Wzc could complement a wza-wzb-wzc defect in E. coli K30, suggesting conservation in their collective function in Wzy-dependent CPS and EPS systems. Expressed individually, colanic acid Wza and Wzb could also function in K30 CPS expression. In contrast, the structural requirements for Wzc function were more stringent because colanic acid Wzc could restore translocation of K30 CPS to the cell surface only when expressed with its cognate Wza protein. Chimeric colanic acid-K30 Wzc proteins were constructed to further study this interaction. These proteins could restore K30 biosynthesis but were unable to couple synthesis to export. The chimeric protein comprising the periplasmic domain of colanic acid Wzc was functional for effective K30 CPS surface expression only when coexpressed with colanic acid Wza. These data highlight the importance of Wza-Wzc interactions in group 1 CPS assembly.

scholarly journals Replacement of GroEL in Escherichia coli by the Group II Chaperonin from the Archaeon Methanococcus maripaludis

2016 ◽  
Vol 198 (19) ◽  
pp. 2692-2700 ◽  
Author(s):  
Riddhi Shah ◽  
Andrew T. Large ◽  
Astrid Ursinus ◽  
Bevan Lin ◽  
Preethy Gowrinathan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Single Point ◽  
Biochemical Properties ◽  
Phylogenetic Groups ◽  
Methanococcus Maripaludis ◽  
Content Type ◽  
E Coli ◽  
Group I ◽  
Group Ii ◽  
Group Ii Chaperonin

ABSTRACTChaperonins are required for correct folding of many proteins. They exist in two phylogenetic groups: group I, found in bacteria and eukaryotic organelles, and group II, found in archaea and eukaryotic cytoplasm. The two groups, while homologous, differ significantly in structure and mechanism. The evolution of group II chaperonins has been proposed to have been crucial in enabling the expansion of the proteome required for eukaryotic evolution. In an archaeal species that expresses both groups of chaperonins, client selection is determined by structural and biochemical properties rather than phylogenetic origin. It is thus predicted that group II chaperonins will be poor at replacing group I chaperonins. We have tested this hypothesis and report here that the group II chaperonin fromMethanococcus maripaludis(Mm-cpn) can partially functionally replace GroEL, the group I chaperonin ofEscherichia coli. Furthermore, we identify and characterize two single point mutations in Mm-cpn that have an enhanced ability to replace GroEL function, including one that allowsE. coligrowth after deletion of thegroELgene. The biochemical properties of the wild-type and mutant Mm-cpn proteins are reported. These data show that the two groups are not as functionally diverse as has been thought and provide a novel platform for genetic dissection of group II chaperonins.IMPORTANCEThe two phylogenetic groups of the essential and ubiquitous chaperonins diverged approximately 3.7 billion years ago. They have similar structures, with two rings of multiple subunits, and their major role is to assist protein folding. However, they differ with regard to the details of their structure, their cofactor requirements, and their reaction cycles. Despite this, we show here that a group II chaperonin from a methanogenic archaeon can partially substitute for the essential group I chaperonin GroEL inE. coliand that we can easily isolate mutant forms of this chaperonin with further improved functionality. This is the first demonstration that these two groups, despite the long time since they diverged, still overlap significantly in their functional properties.

scholarly journals In vivo susceptibility of ESBL producing Escherichia coli to ceftriaxone in children with acute pyelonephritis

2012 ◽  
Vol 140 (5-6) ◽  
pp. 321-325 ◽  
Author(s):  
Amira Peco-Antic ◽  
Dusan Paripovic ◽  
Svetlana Buljugic ◽  
Brankica Spasojevic-Dimitrijeva ◽  
Mirjana Cvetkovic ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acute Pyelonephritis ◽  
Empiric Therapy ◽  
Confirmatory Test ◽  
Diffusion Method ◽  
E Coli ◽  
Group I ◽  
Days Of Therapy ◽  
Group Ii

Introduction. The choice of empiric therapy of acute pyelonephritis (APN) in children should be based on the knowledge of Escherichia coli (E. coli) as the most common uropathogen and its antibiotic sensitivities considering that nowadays ESBL-producing [ESBL (+)] E. coli is on the rise worldwide. Objective. To examine in vivo susceptibility of ESBL (+) E. coli to ceftriaxone (CTX), and to evaluate the options for empiric therapy for APN in children. Methods. Retrospective study of CTX empiric therapy of APN in children treated at the University Children?s Hospital in Belgrade from January 2005 to December 2009. ESBL phenotypic confirmatory test with ceftazidime, CTX and cefotaxime was performed for all urine isolates by disc diffusion method on Mueller-Hinton agar plates. In vivo sensitivity of CTX documented by clinical response to empiric CTX therapy was compared between two groups of children: group I with ESBL (+) E. coli and group II with ESBL (-) E. coli APN. Results. Group I with ESBL (+) APN consisted of 94 patients and group II of 120 patients with ESBL (-) APN, respectively. All patients received CTX as empiric therapy at a mean dose of 66.9 mg during 7.2?2.6 days of therapy. Clinical effect of CTX was similar in patients with ESBL (+) compared to those with ESBL (-) APN. Conclusions. In vitro resistance of ESBL E. coli to CTX determined by standard methods is not sufficiently predictive for its in vivo sensitivity. Therefore CTX may be used as empiric therapy for acute pyelonephritis in children.

scholarly journals Relationship between O-antigen subtypes, bacterial surface structures and O-antigen gene clusters in Escherichia coli O123 strains carrying genes for Shiga toxins and intimin

2007 ◽  
Vol 56 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Lothar Beutin ◽  
Quan Wang ◽  
Dieter Naumann ◽  
Weiqing Han ◽  
Gladys Krause ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid Level ◽  
Gene Clusters ◽  
Surface Structures ◽  
Nucleotide Sequence Analysis ◽  
E Coli ◽  
Antigen Gene ◽  
O Antigen ◽  
Group I ◽  
Group Ii

Escherichia coli O123 strains express a broad spectrum of phenotypes, H serotypes and virulence markers and are able to colonize and to cause disease in different hosts including humans. In this study, two subtypes of E. coli O123 antigen (group I and group II) have been identified based on their cross-reactions with other E. coli O antigens. Investigation of the relationship between O123 group I and group II strains by O serotyping and Fourier transform infrared spectroscopy of whole bacteria revealed surface structural differences between these two groups of E. coli O123 strains. Nucleotide sequence analysis of the O-antigen gene clusters of two E. coli O123 strains representing O123 group I and group II revealed no change at the amino acid level. These findings indicate that the differences in the surface structures of group I and group II strains are not related to genetic heterogeneity in their O-antigen gene clusters. A PCR assay based on O123 antigen-specific wzx and wzy genes was developed and found to be suitable for reliable detection of all subtypes of E. coli O123 strains, which bears an advantage over traditional serological detection.

scholarly journals High-density transposon libraries utilising outward-oriented promoters identify mechanisms of action and resistance to antimicrobials

2020 ◽  
Vol 367 (22) ◽  
Author(s):  
Chris Coward ◽  
Gopujara Dharmalingham ◽  
Omar Abdulle ◽  
Tim Avis ◽  
Stephan Beisken ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Selective Advantage ◽  
Mechanisms Of Action ◽  
Over Expression ◽  
E Coli ◽  
Synthase Inhibitor ◽  
Established Technique ◽  
Bacterial Transposon

ABSTRACT The use of bacterial transposon mutant libraries in phenotypic screens is a well-established technique for determining which genes are essential or advantageous for growth in conditions of interest. Standard, inactivating, transposon libraries cannot give direct information about genes whose over-expression gives a selective advantage. We report the development of a system wherein outward-oriented promoters are included in mini-transposons, generation of transposon mutant libraries in Escherichia coli and Pseudomonas aeruginosa and their use to probe genes important for growth under selection with the antimicrobial fosfomycin, and a recently-developed leucyl-tRNA synthase inhibitor. In addition to the identification of known mechanisms of action and resistance, we identify the carbon–phosphorous lyase complex as a potential resistance liability for fosfomycin in E. coli and P. aeruginosa. The use of this technology can facilitate the development of novel mechanism-of-action antimicrobials that are urgently required to combat the increasing threat worldwide from antimicrobial-resistant pathogenic bacteria.

Prevalence and distribution of different diarrhoeagenicEscherichia colivirulotypes in major water bodies in Bangladesh

2013 ◽  
Vol 141 (12) ◽  
pp. 2516-2525 ◽  
Author(s):  
S. AKTER ◽  
M. ISLAM ◽  
K. S. AFREEN ◽  
N. AZMUDA ◽  
S. I. KHAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Regional Distribution ◽  
Distribution Patterns ◽  
Aquatic Systems ◽  
Water Bodies ◽  
Virulence Determinants ◽  
Waterborne Pathogen ◽  
E Coli ◽  
Enriched Cultures ◽  
Natural Water Bodies

SUMMARYEscherichia coli, a prominent waterborne pathogen, causes a variety of gastrointestinal and extraintestinal infections that depend on virulence determinants. To monitor natural aquatic systems for virulence-associated genes ofE. coli, multiplex PCR was used in a survey covering 46 major natural water bodies in Bangladesh. DNA was extracted directly from water samples as well as from pre-enriched and enriched cultures during three successive seasons and assessed forE. colivirulotype distribution. From the five virulotypes, genes from the enterotoxigenic (ETEC), enteropathogenic (EPEC), and enterohaemorrhagic (EHEC) virulotypes were detected consistently, but genes from the enteroinvasive (EIEC) and enteroaggregative (EAEC) virulotypes were traced only occasionally. ETEC was the most prevalent virulotype, followed by EPEC. However, EIEC and EAEC virulotypes could not be detected in winter or the rainy season, respectively. Specific regional distribution patterns of differentE. colivirulotypes and their temporal fluctuations were identified. These observations may assist with assessing seasonal risk and identifying vulnerable areas of the country prone toE. coli-associated outbreaks.

PCR for the Specific Detection of an Escherichia coli O157:H7 Laboratory Control Strain

2015 ◽  
Vol 78 (9) ◽  
pp. 1738-1744 ◽  
Author(s):  
MICHAEL KNOWLES ◽  
DOMINIC LAMBERT ◽  
GEORGE HUSZCZYNSKI ◽  
MARTINE GAUTHIER ◽  
BURTON W. BLAIS
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Control Measure ◽  
Positive Control ◽  
Food Microbiology ◽  
Escherichia Coli O157 ◽  
Control Strain ◽  
E Coli ◽  
Signature Sequences ◽  
Materials Used

Control strains of bacterial pathogens such as Escherichia coli O157:H7 are commonly processed in parallel with test samples in food microbiology laboratories as a quality control measure to assure the satisfactory performance of materials used in the analytical procedure. Before positive findings can be reported for risk management purposes, analysts must have a means of verifying that pathogenic bacteria (e.g., E. coli O157:H7) recovered from test samples are not due to inadvertent contamination with the control strain routinely handled in the laboratory environment. Here, we report on the application of an in-house bioinformatic pipeline for the identification of unique genomic signature sequences in the development of specific oligonucleotide primers enabling the identification of a common positive control strain, E. coli O157:H7 (ATCC 35150), using a simple PCR procedure.

scholarly journals Cloning of Salmonella enterica Serovar Enteritidis Fimbrial Protein SefA as a Surface Protein in Escherichia coli Confers the Ability To Attach to Eukaryotic Cell Lines

2009 ◽  
Vol 75 (20) ◽  
pp. 6622-6625 ◽  
Author(s):  
Douglas L. Rank ◽  
Mahdi A. Saeed ◽  
Peter M. Muriana
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Expression Vector ◽  
Surface Protein ◽  
Surface Expression ◽  
Eukaryotic Cell ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Western Blot Assay ◽  
E Coli ◽  
Fimbrial Protein

ABSTRACT The gene for the Salmonella enterica serovar Enteritidis fimbrial protein SefA was cloned into an Escherichia coli surface expression vector and confirmed by Western blot assay. E. coli clones expressing SefA attached to avian ovary granulosa cells and HEp-2 cells, providing evidence for the involvement of SefA in the ability of Salmonella to attach to eukaryotic cells.

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