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Sample records for coli f41 fimbrial

  1. Monoclonal antibody passive hemagglutination and capture enzyme-linked immunosorbent assays for direct detection and quantitation of F41 and K99 fimbrial antigens in enterotoxigenic Escherichia coli.

    PubMed Central

    Raybould, T J; Crouch, C F; Acres, S D

    1987-01-01

    Production of diarrhea in neonatal calves by enterotoxigenic Escherichia coli depends on its ability to attach to the epithelial cells of the intestine via surface adhesins called pili or fimbriae and to secrete enterotoxins. The most important of these fimbriae are designated K99 and F41. We produced and characterized a murine monoclonal antibody specific to F41. This monoclonal antibody and a K99-specific monoclonal antibody were used to develop sensitive and specific passive hemagglutination and capture enzyme-linked immunosorbent assays (ELISAs) for detection and quantitation of F41 and K99 antigens in E. coli cultures and culture supernatants. The capture ELISA systems exhibited excellent sensitivity and specificity, whereas the passive hemagglutination systems appeared to be oversensitive. The ability of the capture ELISAs to detect K99 and F41 fimbrial antigens in fecal specimens from calves was evaluated. Fimbrial antigens were detected in six of six specimens from scouring calves but not in four of four specimens from nonscouring calves. PMID:2880866

  2. F41 pili as protective antigens of enterotoxigenic Escherichia coli that produce F41, K99, or both pilus antigens.

    PubMed Central

    Runnels, P L; Moseley, S L; Moon, H W

    1987-01-01

    Pigs suckling dams that have been vaccinated with pilus antigen are protected against challenge with enterotoxigenic Escherichia coli (ETEC) strains that express the same pilus antigen. However, some ETEC strains express more than one pilus antigen. Pregnant swine were vaccinated either with E. coli HB101 that harbored a recombinant plasmid coding for F41 expression (F41+) or with the HB101 parent strain that carries the pHC79 vector (F41-). Suckling pigs born to vaccinated dams were challenged with ETEC that expressed either K99, F41, or both pilus antigens. Production of F41 in vivo was demonstrated by immunofluorescence assay of sections of ileum and by seroconversion against F41 antigen by pigs challenged with F41+ and K99+ F41+ ETEC strains. The F41+ vaccine protected against challenge with an F41+ ETEC strain. In contrast, F41+ vaccination did not protect against challenge with K99+ or K99+ F41+ ETEC strains. The F41- vaccine did not protect against challenge with any strain used. The results indicate that K99+ F41+ ETEC strains produce F41 antigen in the small intestine during disease and that F41+ vaccination can be a protective antigen if the challenge strain expresses only F41 antigen, but that F41+ vaccination may not protect against strains that produce both K99 and F41 antigens. PMID:2880807

  3. Requirement for capsular antigen KX105 and fimbrial antigen CS1541 in the pathogenicity of porcine enterotoxigenic Escherichia coli O8:KX105 strains.

    PubMed Central

    Broes, A; Fairbrother, J M; Jacques, M; Larivière, S

    1989-01-01

    The requirement for capsular antigen KX105 and fimbrial antigen CS1541 in the pathogenicity of porcine enterotoxigenic Escherichia coli O8:KX105 strains lacking the colonization factor antigens K88, K99, 987P and F41 was investigated using two encapsulated strains and their acapsular variants, one of which produced the fimbrial antigen CS1541 in vitro. None of the strains adhered in vitro to enterocytes isolated from newborn colostrum-deprived piglets. All of the strains caused diarrhea in orally infected, hysterotomy-derived, colostrum-deprived piglets although a great variability in the clinical response of the piglets was observed. Colonization of the small intestine of infected piglets by these strains was only moderate and no differences in the ability to colonize the small intestine was noted between the strains. All of the strains reacted in the indirect fluorescent antibody test with both CS1541 and 987P antisera when applied to organisms in the intestines of infected piglets. A control strain expressing the 987P fimbrial adhesin also reacted with the CS1541 antiserum applied to organisms in the intestines of an infected piglet. It was concluded that capsular antigen KX105 was not essential for intestinal colonization and production of diarrhea in hysterotomy-derived colostrum-deprived pigs, and that fimbrial antigen CS1541 does not promote in vitro adherence to enterocyte brush borders but could be important in bacterial colonization in vivo. Images Fig. 1. Fig. 2. Fig. 3. PMID:2563336

  4. Pathogenicity of porcine enterotoxigenic Escherichia coli that do not express K88, K99, F41, or 987P adhesins.

    PubMed

    Casey, T A; Nagy, B; Moon, H W

    1992-09-01

    Three-week-old weaned and colostrum-deprived neonatal (less than 1 day old) pigs were inoculated to determine the pathogenicity of 2 enterotoxigenic Escherichia coli isolates that do not express K88, K99, F41, or 987P adhesins (strains 2134 and 2171). Strains 2134 and 2171 were isolated from pigs that had diarrhea after weaning attributable to enterotoxigenic E coli infection. We found that both strains of E coli adhered in the ileum and caused diarrhea in pigs of both age groups. In control experiments, adherent bacteria were not seen in the ileum of pigs less than 1 day old or 3 weeks old that were noninoculated or inoculated with a nonpathogenic strain of E coli. These control pigs did not develop diarrhea. Antisera raised against strains 2134 and 2171 and absorbed with the autologous strain, grown at 18 C, were used for bacterial-agglutination and colony-immunoblot assays. Both absorbed antisera reacted with strains 2134 and 2171, but not with strains that express K99, F41, or 987P adhesins. A cross-reaction was observed with 2 wild-type K88 strains, but not with a K12 strain that expresses K88 pili. Indirect immunofluorescence with these absorbed antisera revealed adherent bacteria in frozen sections of ileum from pigs infected with either strain. We concluded that these strains are pathogenic and express a common surface antigen that may be a novel adhesin in E coli strains that cause diarrhea in weaned pigs.

  5. Effect of Temperature on Fimbrial Gene Expression and Adherence of Enteroaggregative Escherichia coli.

    PubMed

    Hinthong, Woranich; Indrawattana, Nitaya; Pitaksajjakul, Pannamthip; Pipattanaboon, Chonlatip; Kongngoen, Thida; Tharnpoophasiam, Prapin; Worakhunpiset, Suwalee

    2015-07-23

    The influence of temperature on bacterial virulence has been studied worldwide from the viewpoint of climate change and global warming. The bacterium enteroaggregative Escherichia coli (EAEC) is the causative agent of watery diarrhea and shows an increasing incidence worldwide. Its pathogenicity is associated with the virulence factors aggregative adherence fimbria type I and II (AAFI and AAFII), encoded by aggA and aafA in EAEC strains 17-2 and 042, respectively. This study focused on the effect of temperature increases from 29 °C to 40 °C on fimbrial gene expression using real-time PCR, and on its virulence using an aggregative adherence assay and biofilm formation assay. Incubation at 32 °C caused an up-regulation in both EAEC strains 17-2 and strain 042 virulence gene expression. EAEC strain 042 cultured at temperature above 32 °C showed down-regulation of aafA expression except at 38 °C. Interestingly, EAEC cultured at a high temperature showed a reduced adherence to cells and an uneven biofilm formation. These results provide evidence that increases in temperature potentially affect the virulence of pathogenic EAEC, although the response varies in each strain.

  6. Biosensor for selective detection of E. coli in spinach using the strong affinity of derivatized mannose with fimbrial lectin.

    PubMed

    Yazgan, Idris; Noah, Naumih M; Toure, Ousmane; Zhang, Siyi; Sadik, Omowunmi A

    2014-11-15

    Escherichia coli (E. coli) contamination in foods and water resources represents a major threat for human health and the environment. This work exploits the strong affinity of mannose-containing oligosaccharides with the fimbrial lectin of E. coli to design novel biosensors. Modified carbohydrate ligands were synthesized by introducing phenyl residues and aliphatic chains to mannose via reductive amination in order to increase both the affinity and selectivity to E. coli compared to other pathogenic bacteria. The synthesized ligands include p-thiolphenyl aminomannose (PTAM), p-carboxyphenyl aminomannose (PCAM), 1-deoxy-1-aminomannopyranoside (DAMP), glucosamine and low molecular weight chitosan bonded to mercapto undecanoic acid. The structures of the ligands were confirmed using (1)H NMR and 1H, (13)C, COZY NMR, and ESI/MS. The ligands were immobilized onto gold electrodes and SPR surfaces using-mercaptoundecanoic acid with glycine as deactivating agent. Two detection mechanisms were tested: (i) metal-enhanced electrochemical detection (MED) and (ii) label-free surface plasmon resonance (SPR) detection. The introduction of phenyl residues and aliphatic side groups to the mannose-containing oligosaccharides produced extremely high affinity for E. coli with detection limit of 1 cfu/mL. The relative selectivity of these ligands for E. coli, Citrobacter freundii, Staphylococcus epidermidis were 100%, 2.6% and 8.6% respectively. The biosensors were validated using spinach leaves at 3.0 cfu/mL. The work provides a generic biosensor for other pathogenic bacteria by enabling multivalent binding, immediate recognition for pathogens as well as inhibition of bacterial growth.

  7. Maternal Vaccination with a Fimbrial Tip Adhesin and Passive Protection of Neonatal Mice against Lethal Human Enterotoxigenic Escherichia coli Challenge

    PubMed Central

    Luiz, Wilson B.; Rodrigues, Juliana F.; Crabb, Joseph H.

    2015-01-01

    Globally, enterotoxigenic Escherichia coli (ETEC) is a leading cause of childhood and travelers' diarrhea, for which an effective vaccine is needed. Prevalent intestinal colonization factors (CFs) such as CFA/I fimbriae and heat-labile enterotoxin (LT) are important virulence factors and protective antigens. We tested the hypothesis that donor strand-complemented CfaE (dscCfaE), a stabilized form of the CFA/I fimbrial tip adhesin, is a protective antigen, using a lethal neonatal mouse ETEC challenge model and passive dam vaccination. For CFA/I-ETEC strain H10407, which has been extensively studied in volunteers, an inoculum of 2 × 107 bacteria resulted in 50% lethal doses (LD50) in neonatal DBA/2 mice. Vaccination of female DBA/2 mice with CFA/I fimbriae or dscCfaE, each given with a genetically attenuated LT adjuvant (LTK63) by intranasal or orogastric delivery, induced high antigen-specific serum IgG and fecal IgA titers and detectable milk IgA responses. Neonates born to and suckled by dams antenatally vaccinated with each of these four regimens showed 78 to 93% survival after a 20× LD50 challenge with H10407, compared to 100% mortality in pups from dams vaccinated with sham vaccine or LTK63 only. Crossover experiments showed that high pup survival rates after ETEC challenge were associated with suckling but not birthing from vaccinated dams, suggesting that vaccine-specific milk antibodies are protective. In corroboration, preincubation of the ETEC inoculum with antiadhesin and antifimbrial bovine colostral antibodies conferred a dose-dependent increase in pup survival after challenge. These findings indicate that the dscCfaE fimbrial tip adhesin serves as a protective passive vaccine antigen in this small animal model and merits further evaluation. PMID:26371126

  8. Dimeric and Trimeric Fusion Proteins Generated with Fimbrial Adhesins of Uropathogenic Escherichia coli.

    PubMed

    Luna-Pineda, Víctor M; Reyes-Grajeda, Juan Pablo; Cruz-Córdova, Ariadnna; Saldaña-Ahuactzi, Zeus; Ochoa, Sara A; Maldonado-Bernal, Carmen; Cázares-Domínguez, Vicenta; Moreno-Fierros, Leticia; Arellano-Galindo, José; Hernández-Castro, Rigoberto; Xicohtencatl-Cortes, Juan

    2016-01-01

    Urinary tract infections (UTIs) are associated with high rates of morbidity and mortality worldwide, and uropathogenic Escherichia coli (UPEC) is the main etiologic agent. Fimbriae assembled on the bacterial surface are essential for adhesion to the urinary tract epithelium. In this study, the FimH, CsgA, and PapG adhesins were fused to generate biomolecules for use as potential target vaccines against UTIs. The fusion protein design was generated using bioinformatics tools, and template fusion gene sequences were synthesized by GenScript in the following order fimH-csgA-papG-fimH-csgA (fcpfc) linked to the nucleotide sequence encoding the [EAAAK]5 peptide. Monomeric (fimH, csgA, and papG), dimeric (fimH-csgA), and trimeric (fimH-csgA-papG) genes were cloned into the pLATE31 expression vector and generated products of 1040, 539, 1139, 1442, and 2444 bp, respectively. Fusion protein expression in BL21 E. coli was induced with 1 mM IPTG, and His-tagged proteins were purified under denaturing conditions and refolded by dialysis using C-buffer. Coomassie blue-stained SDS-PAGE gels and Western blot analysis revealed bands of 29.5, 11.9, 33.9, 44.9, and 82.1 kDa, corresponding to FimH, CsgA, PapG, FC, and FCP proteins, respectively. Mass spectrometry analysis by MALDI-TOF/TOF revealed specific peptides that confirmed the fusion protein structures. Dynamic light scattering analysis revealed the polydispersed state of the fusion proteins. FimH, CsgA, and PapG stimulated the release of 372-398 pg/mL IL-6; interestingly, FC and FCP stimulated the release of 464.79 pg/mL (p ≤ 0.018) and 521.24 pg/mL (p ≤ 0.002) IL-6, respectively. In addition, FC and FCP stimulated the release of 398.52 pg/mL (p ≤ 0.001) and 450.40 pg/mL (p ≤ 0.002) IL-8, respectively. High levels of IgA and IgG antibodies in human sera reacted against the fusion proteins, and under identical conditions, low levels of IgA and IgG antibodies were detected in human urine. Rabbit polyclonal antibodies

  9. Dimeric and Trimeric Fusion Proteins Generated with Fimbrial Adhesins of Uropathogenic Escherichia coli

    PubMed Central

    Luna-Pineda, Víctor M.; Reyes-Grajeda, Juan Pablo; Cruz-Córdova, Ariadnna; Saldaña-Ahuactzi, Zeus; Ochoa, Sara A.; Maldonado-Bernal, Carmen; Cázares-Domínguez, Vicenta; Moreno-Fierros, Leticia; Arellano-Galindo, José; Hernández-Castro, Rigoberto; Xicohtencatl-Cortes, Juan

    2016-01-01

    Urinary tract infections (UTIs) are associated with high rates of morbidity and mortality worldwide, and uropathogenic Escherichia coli (UPEC) is the main etiologic agent. Fimbriae assembled on the bacterial surface are essential for adhesion to the urinary tract epithelium. In this study, the FimH, CsgA, and PapG adhesins were fused to generate biomolecules for use as potential target vaccines against UTIs. The fusion protein design was generated using bioinformatics tools, and template fusion gene sequences were synthesized by GenScript in the following order fimH-csgA-papG-fimH-csgA (fcpfc) linked to the nucleotide sequence encoding the [EAAAK]5 peptide. Monomeric (fimH, csgA, and papG), dimeric (fimH-csgA), and trimeric (fimH-csgA-papG) genes were cloned into the pLATE31 expression vector and generated products of 1040, 539, 1139, 1442, and 2444 bp, respectively. Fusion protein expression in BL21 E. coli was induced with 1 mM IPTG, and His-tagged proteins were purified under denaturing conditions and refolded by dialysis using C-buffer. Coomassie blue-stained SDS-PAGE gels and Western blot analysis revealed bands of 29.5, 11.9, 33.9, 44.9, and 82.1 kDa, corresponding to FimH, CsgA, PapG, FC, and FCP proteins, respectively. Mass spectrometry analysis by MALDI-TOF/TOF revealed specific peptides that confirmed the fusion protein structures. Dynamic light scattering analysis revealed the polydispersed state of the fusion proteins. FimH, CsgA, and PapG stimulated the release of 372–398 pg/mL IL-6; interestingly, FC and FCP stimulated the release of 464.79 pg/mL (p ≤ 0.018) and 521.24 pg/mL (p ≤ 0.002) IL-6, respectively. In addition, FC and FCP stimulated the release of 398.52 pg/mL (p ≤ 0.001) and 450.40 pg/mL (p ≤ 0.002) IL-8, respectively. High levels of IgA and IgG antibodies in human sera reacted against the fusion proteins, and under identical conditions, low levels of IgA and IgG antibodies were detected in human urine. Rabbit polyclonal antibodies

  10. Surface expression of Helicobacter pylori HpaA adhesion antigen on Vibrio cholerae, enhanced by co-expressed enterotoxigenic Escherichia coli fimbrial antigens.

    PubMed

    Tobias, Joshua; Lebens, Michael; Wai, Sun Nyunt; Holmgren, Jan; Svennerholm, Ann-Mari

    2017-02-17

    Helicobacter pylori infection can cause peptic ulceration and is associated with gastric adenocarcinoma. This study aimed to construct and characterize a non-virulent Vibrio cholerae O1 strain, which grows more rapidly than H. pylori, as vector for H. pylori antigens for possible use as a vaccine strain against H. pylori. This was done by recombinant expression of the H. pylori adhesion antigen HpaA alone or, as a proof of principle, together with different colonization factor (CF) antigens of enterotoxigenic Escherichia coli (ETEC) which may enhance immune responses against HpaA. A recombinant V. cholerae strain co-expressing HpaA and a fimbrial CF antigens CFA/I or CS5, but not the non-fimbrial CF protein CS6, was shown to express larger amounts of HpaA on the surface when compared with the same V. cholerae strain expressing HpaA alone. Mutations in the CFA/I operon showed that the chaperon, possibly together with the usher, was involved in enhancing the surface expression of HpaA. Oral immunization of mice with formaldehyde-inactivated recombinant V. cholerae expressing HpaA alone or together with CFA/I induced significantly higher serum antibody responses against HpaA than mice similarly immunized with inactivated HpaA-expressing H. pylori bacteria. Our results demonstrate that a non-virulent V. cholerae strain can be engineered to allow strong surface expression of HpaA, and that the expression can be further increased by co-expressing it with ETEC fimbrial antigens. Such recombinant V. cholerae strains expressing HpaA, and possibly also other H. pylori antigens, may have the potential as oral inactivated vaccine candidates against H. pylori.

  11. Integration of minitransposons for expression of the Escherichia coli elt genes at a preferred site in Salmonella typhimurium identifies a novel putative fimbrial locus.

    PubMed

    Brocchi, M; Covone, M G; Palla, E; Galeotti, C L

    1999-01-01

    An asd-complementing mini-Tn5 transposon was constructed for random insertion of the Escherichia coli LT enterotoxin genes (elt) into the genome of Deltaasd attenuated strains of Salmonella typhimurium. Transfer of the minitransposon to different S. typhimurium strains resulted in random integration only in strain chi4072, while in strain chi3987, which harbours the virulence plasmid, over 20% of the insertions occurred at the same site. Expression of elt was found to be highest in Salmonella isolates carrying the mini-Tn5 integrated at the preferred site, which was mapped to an uncharacterised region of the virulence plasmid. Sequence analysis of the integration site showed that it lies within an open reading frame with sequence similarity to E. coli leuO and contiguous to a novel fimbrial locus.

  12. Differentiation of Crohn’s Disease-Associated Isolates from Other Pathogenic Escherichia coli by Fimbrial Adhesion under Shear Force

    PubMed Central

    Szunerits, Sabine; Zagorodko, Oleksandr; Cogez, Virginie; Dumych, Tetiana; Chalopin, Thibaut; Alvarez Dorta, Dimitri; Sivignon, Adeline; Barnich, Nicolas; Harduin-Lepers, Anne; Larroulet, Iban; Yanguas Serrano, Aritz; Siriwardena, Aloysius; Pesquera, Amaia; Zurutuza, Amaia; Gouin, Sébastien G.; Boukherroub, Rabah; Bouckaert, Julie

    2016-01-01

    Shear force exerted on uropathogenic Escherichia coli adhering to surfaces makes type-1 fimbriae stretch out like springs to catch on to mannosidic receptors. This mechanism is initiated by a disruption of the quaternary interactions between the lectin and the pilin of the two-domain FimH adhesin and transduces allosterically to the mannose-binding pocket of FimH to increase its affinity. Mannose-specific adhesion of 14 E. coli pathovars was measured under flow, using surface plasmon resonance detection on functionalized graphene-coated gold interfaces. Increasing the shear had important differential consequences on bacterial adhesion. Adherent-invasive E. coli, isolated from the feces and biopsies of Crohn’s disease patients, consistently changed their adhesion behavior less under shear and displayed lower SPR signals, compared to E. coli opportunistically infecting the urinary tract, intestines or loci of knee and hip prostheses. We exemplified this further with the extreme behaviors of the reference strains UTI89 and LF82. Whereas their FimA major pilins have identical sequences, FimH of LF82 E. coli is marked by the Thr158Pro mutation. Positioned in the inter-domain region known to carry hot spots of mutations in E. coli pathotypes, residue 158 is indicated to play a structural role in the allosteric regulation of type-1 fimbriae-mediated bacterial adhesion. PMID:27043645

  13. [Cloning and expression of F18 fimbrial operon gene clusters from enterotoxigenic Escherichia coli and their bioactivity].

    PubMed

    Zhang, Jian-Jun; Zhu, Guo-Qiang

    2007-10-01

    The fed operon gene clusters with each size of 5.6kb, encoding the F18ab or F18ac fimbriae, was amplified respectively by high fidelity PCR using the genomic DNA templates from F18 fimbriae E. coli strains 107/86 or 2134P. The PCR products with the restriction enzyme sites at each end were digested and then cloned into the vector pET-22b (+), the recombinant plamids with the inserts of both type of fed gene clusters were constructed and screened, further confirmed by the means of combination with restriction endonuclease analysis and sequencing. The both types of fimbriae F18ab and F18ac were expressed efficiently in the E. coli BL21 (DE3) after proper concentration of IPTG induction. Expressed fimbriae were revealed and confirmed by transmissible electromicroscope observation. The both fimbriae F18ab and F18ac were isolated and purified from the recombinant E. coli, and only a single major band of protein with size of approximately 15kDa was visualized in Coomassie blue-stained gels after SDS-PAGE. The rabbits sera with high titer of anti-F18 fimbriae were detected after being immunized with the purified F18ab or F18ac fimbriae. The results of combination of agglutination assay with Western blotting showed that the sera directed against both fimbriae F18ab and F18ac reacted positively with the F18 fimbriae from both wild E. coli 107/86 and 2134P. Small intestine epithelial cells with F18 fimbriae receptors, which were from post-weaning piglets with the genotypes of FUT1 gene both M307(GG) and M307(AG), were prepared and tested for the adherence of E. coli expressing F18 fimbriae under the microscopic examination. Adhesion and adhesion inhibition test showed both of the recombinant E. coli expressing F18ab or F18ac fimbriae respectively could adhere to the jejunal epithelial cells in vitro as E. coli 107/86 and 2134p did. The both of anti-sera directed against fimbriae F18ab or F18ac respectively can efficiently inhibit the fimbriae-mediated post-weaning piglet

  14. Characterization of porcine intestinal receptors for the K88ac fimbrial adhesin of Escherichia coli as mucin-type sialoglycoproteins.

    PubMed Central

    Erickson, A K; Baker, D R; Bosworth, B T; Casey, T A; Benfield, D A; Francis, D H

    1994-01-01

    We have previously identified two K88ac adhesion receptors (210 and 240 kDa) which are present in membrane preparations from adhesive but not nonadhesive porcine intestinal brush border cells; these adhesin receptors are postulated to be important determinants of the susceptibility of pigs to K88ac+ enterotoxigenic Escherichia coli infections (A.K. Erickson, J.A. Willgohs, S.Y. McFarland, D.A. Benfield, and D.F. Francis, Infect. Immun. 60:983-988, 1992). We now describe a procedure for the purification of these two receptors. Receptors were solubilized from adhesive intestinal brush border vesicles using deoxycholate and were purified by gel filtration chromatography on Sepharose CL-4B and then by hydroxyapatite chromatography. Amino acid compositional analyses indicated that the two receptors have similar amino acid compositions. The most distinguishing characteristic of both receptors is a high percentage of threonine and proline residues. Neuraminidase treatment caused the K88ac adhesin receptors to migrate with a slower mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels, indicating that these receptors are sialoglycoproteins. Results from lectin-binding studies indicated that the receptors contain O-linked oligosaccharides composed of galactosyl (beta-1,3)N-acetylgalactosamine, alpha-linked fucose, galactosyl(beta-1,4)N-acetylglucosamine, sialic acid, galactose, and N-acetylgalactosamine. Collectively, these characteristics indicate that the K88ac adhesin receptors are mucin-type sialoglycoproteins. Images PMID:7960120

  15. The Use of Specific Antibodies to Demonstrate the Glycocalyx and Spatial Relationships of a K99-, F41- Enterotoxigenic Strain of Escherichia coli Colonizing the Ileum of Colostrum-deprived Calves

    PubMed Central

    Chan, R.; Lian, C.J.; Costerton, J.W.; Acres, S.D.

    1983-01-01

    Electron microscopy was used to study the interaction between the glycocalyx of enterotoxigenic Escherichia coli strain 210 (09:K30+;K99-;F41-:H-) and the glycocalyx of epithelial cells in then ileum of experimentally infected newborn colostrum-deprived calves. Fixation of tissues in anti-K30 antibody and ruthenium red was used to stabilize the bacterial glycocalyx so that the spatial relationship between the bacteria and the intestinal epithelial cells could be characterized. When strain 210 was grown in vitro and reacted with anti-K30 antibody prior to staining with ruthenium red, the extensive glycocalyx could be clearly visualized surrounding the bacterial cells. By negative staining, an unidentified pilus was also seen. Sections of ileum from infected calves, which were not fixed in antibody nor stained with ruthenium red, revealed attached bacteria which were surrounded by an electron-translucent zone and no visible bacterial glycocalyx. When ruthenium red staining was used, the bacterial glycocalyx partially collapsed during the dehydration steps of fixation, but could be seen as either a fibrous capsule or an electron-dense accretion on the bacterial cell surface. When ileal tissue was reacted for one hour in anti-K30 antibody before staining with ruthenium red, the bacterial glycocalyx was seen as a discrete electron-dense structure up to 1.0µm thick which was in intimate contact with the glycocalyx of the epithelial cells. The importance of the bacterial exopolysaccharide to microcolony formation on the villi could be clearly visualized. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5.Fig. 6.Fig. 7. PMID:6349756

  16. Designations F18ab and F18ac for the related fimbrial types F107, 2134P and 8813 of Escherichia coli isolated from porcine postweaning diarrhoea and from oedema disease.

    PubMed

    Rippinger, P; Bertschinger, H U; Imberechts, H; Nagy, B; Sorg, I; Stamm, M; Wild, P; Wittig, W

    1995-08-01

    The relatedness of the fimbriae produced by eight E. coli strains including type strains with F107 fimbriae, 2134P pili and colonization factor 8813 (preliminary F18), was examined. These strains had been isolated principally from pigs which were affected with postweaning diarrhoea or with oedema disease. The fimbriae were analyzed by means of electron microscopy, slide agglutination, immunofluorescence, immunogold labelling, immuno-diffusion, immunoelectrophoresis and western blot, molecular genetic techniques, and in vitro adhesion. The fimbriae of all the strains were long flexible filaments with a diameter not larger than 4.6 nm showing a zig-zag pattern. Results obtained by the serological techniques confirmed that the fimbriae possessed a common antigenic determinant designated 'a' in addition to a variant-specific determinant designated 'b' or 'c'. Immunoelectron microscopy demonstrated that the determinants 'a' and 'b' or 'a' and 'c' were localized along the same fimbrium. In immunoelectrophoresis, fimbrial extracts of selected strains yielded a single precipitation line towards the cathode. One single major subunit of approximately 15 kDa was recognised in western blots by antisera against the common antigenic determinant and the variant specific determinants. All strains possessed sequences related to gene fedA, coding for the major subunit of fimbriae F107. Two types of fedA-related subunit genes were differentiated, corresponding to the 'ab' and 'ac' types of fimbriae as defined by serological methods. The results demonstrated that F107 fimbriae, 2134P pili and colonization factor 8813 are related, and that two serological variants can be distinguished. We propose designations F18ab (for F107), and F18ac (for 2134P and 8813) in analogy to the nomenclature of F4 fimbriae.

  17. Mutation of Tyr137 of the universal Escherichia coli fimbrial adhesin FimH relaxes the tyrosine gate prior to mannose binding

    PubMed Central

    Rabbani, Said; Krammer, Eva-Maria; Roos, Goedele; Zalewski, Adam; Preston, Roland; Eid, Sameh; Zihlmann, Pascal; Prévost, Martine; Lensink, Marc F.; Thompson, Andrew; Ernst, Beat; Bouckaert, Julie

    2017-01-01

    The most prevalent diseases manifested by Escherichia coli are acute and recurrent bladder infections and chronic inflammatory bowel diseases such as Crohn’s disease. E. coli clinical isolates express the FimH adhesin, which consists of a mannose-specific lectin domain connected via a pilin domain to the tip of type 1 pili. Although the isolated FimH lectin domain has affinities in the nanomolar range for all high-mannosidic glycans, differentiation between these glycans is based on their capacity to form predominantly hydrophobic interactions within the tyrosine gate at the entrance to the binding pocket. In this study, novel crystal structures of tyrosine-gate mutants of FimH, ligand-free or in complex with heptyl α-d-O-mannopyranoside or 4-biphenyl α-d-O-mannopyranoside, are combined with quantum-mechanical calculations and molecular-dynamics simulations. In the Y48A FimH crystal structure, a large increase in the dynamics of the alkyl chain of heptyl α-d-O-mannopyranoside attempts to compensate for the absence of the aromatic ring; however, the highly energetic and stringent mannose-binding pocket of wild-type FimH is largely maintained. The Y137A mutation, on the other hand, is the most detrimental to FimH affinity and specificity: (i) in the absence of ligand the FimH C-terminal residue Thr158 intrudes into the mannose-binding pocket and (ii) ethylenediaminetetraacetic acid interacts strongly with Glu50, Thr53 and Asn136, in spite of multiple dialysis and purification steps. Upon mutation, pre-ligand-binding relaxation of the backbone dihedral angles at position 137 in the tyrosine gate and their coupling to Tyr48 via the interiorly located Ile52 form the basis of the loss of affinity of the FimH adhesin in the Y137A mutant. PMID:28250938

  18. Generation of Salmonella ghost cells expressing fimbrial antigens of enterotoxigenic Escherichia coli and evaluation of their antigenicity in a murine model

    PubMed Central

    Kim, Chan Song; Hur, Jin; Eo, Seong Kug; Park, Sang-Youel; Lee, John Hwa

    2016-01-01

    Salmonella Typhimurium ghost cells expressing K88ab, K88ac, K99, and FasA fimbriae of enterotoxigenic Escherichia coli (ETEC) in their envelopes were constructed. The genes encoding the fimbriae were individually cloned into an expression plasmid, pMMP81, carrying the asd gene, which was subsequently electroporated into the Δasd S. Typhimurium mutant. Plasmid pJHLP99, carrying the phiX174 lysis gene E, was also subsequently electroporated into the Salmonella mutant. The presence of the individual fimbriae on the ghost cells was examined by Western blot analysis. Forty BALB/c mice were equally divided into 2 groups of 20 mice each. Group A mice were intramuscularly vaccinated with a mixture of the 4 ghost cells expressing the individual fimbriae. The group B mice were inoculated with sterile phosphate-buffered saline as a control. The antigen-specific serum IgG concentrations were significantly higher in group A than in group B from week 2 until week 6 after inoculation. In addition, the antigen-specific IgA concentrations in fecal samples were significantly higher in group A than in group B at week 2 after inoculation. A large difference between the groups in the number of antigen-specific IgA-secreting cells in the small intestine was observed by immunohistochemical study. Also, the splenic lymphocyte proliferative responses were significantly greater in group A than in the control mice. These results suggest that vaccination with our Salmonella ghost cells can induce both humoral and cell-mediated immune responses and that the increased number of antigen-specific IgA-secreting cells in the small intestine may be correlated with the elevated fecal IgA immune response. PMID:26733731

  19. A vaccine candidate for post-weaning diarrhea in swine constructed with a live attenuated Salmonella delivering Escherichia coli K88ab, K88ac, FedA, and FedF fimbrial antigens and its immune responses in a murine model.

    PubMed

    Hur, Jin; Stein, Barry D; Lee, John Hwa

    2012-07-01

    In order to construct a novel vaccine candidate for preventing post-weaning diarrhea in swine, the individual genes for Escherichia coli K88ab, K88ac, FedA, and FedF fimbriae were inserted into a secretion plasmid pBP244 containing asd, lepB, secA, and secB. These were transformed into Salmonella Typhimurium Δlon ΔcpxR Δasd. Secretion of the individual recombinant fimbrial antigens was confirmed by immunoblot analysis. Groups 1 and 2 mice received a single oral dose of the vaccine mixture and S. Typhimurium carrying pBP244 only as a control, respectively. In groups 3 and 4, mice were primed and boosted with the vaccine mixture and S. Typhimurium carrying pBP244 only as a control, respectively. In general, all immunized mice had significantly increased serum immunoglobulin (Ig)G (P < 0.05) and intestinal secretory IgA against the individual fimbrial antigens compared with those mice in the control group. In the IgG2a and IgG1 titer assay, only IgG2a titer was increased in group 1, while both IgG2a and IgG1 titers were increased in group 3. Furthermore, the vaccine strains were not detected in the excreted feces of any immunized mice. Thus, the vaccine candidate can be highly immunogenic and be safe to the environment.

  20. Protective antibody titres and antigenic competition in multivalent Dichelobacter nodosus fimbrial vaccines using characterised rDNA antigens.

    PubMed

    Raadsma, H W; O'Meara, T J; Egerton, J R; Lehrbach, P R; Schwartzkoff, C L

    1994-03-01

    The relationship between K-agglutination antibody titres and protection against experimental challenge with Dichelobacter nodosus, the effect of increasing the number of D. nodosus fimbrial antigens, and the importance of the nature of additional antigens in multivalent vaccines on antibody response and protection against experimental challenge with D. nodosus were examined in Merino sheep. A total of 204 Merino sheep were allocated to one of 12 groups, and vaccinated with preparations containing a variable number of rDNA D. nodosus fimbrial antigens. The most complex vaccine contained ten fimbrial antigens from all major D. nodosus serogroups, while the least complex contained a single fimbrial antigen. In addition to D. nodosus fimbrial antigens, other bacterial rDNA fimbrial antigens (Moraxella bovis Da12d and Escherichia coli K99), and bovine serum albumin (BSA) were used in some vaccines. Antibody titres to fimbrial antigens and BSA were measured by agglutination and ELISA tests, respectively. Antibody titres were determined on five occasions (Weeks 0, 3, 6, 8, and 11 after primary vaccination). All sheep were exposed to an experimental challenge with virulent isolates of D. nodosus from either serogroup A or B, 8 weeks after primary vaccination. For D. nodosus K-agglutinating antibody titres, a strong negative correlation between antibody titre and footrot lesion score was observed. This relationship was influenced by the virulence of the challenge strain. Increasing the number of fimbrial antigens in experimental rDNA D. nodosus fimbrial vaccines resulted in a linear decrease in K-agglutinating antibody titres to individual D. nodosus serogroups. Similarly, a linear decrease in protection to challenge with homologous serogroups was observed as the number of D. nodosus fimbrial antigens represented in the vaccine increased. The reduction in antibody titres in multicomponent vaccines is thought to be due to antigenic competition. The level of competition

  1. Mapping the Binding Domain of the F18 Fimbrial Adhesin

    PubMed Central

    Smeds, A.; Pertovaara, M.; Timonen, T.; Pohjanvirta, T.; Pelkonen, S.; Palva, A.

    2003-01-01

    F18 fimbrial Esherichia coli strains are associated with porcine postweaning diarrhea and pig edema disease. Recently, the FedF subunit was identified as the adhesin of the F18 fimbriae. In this study, adhesion domains of FedF were further studied by constructing deletions within the fedF gene and expressing FedF proteins with deletions either together with the other F18 fimbrial subunits or as fusion proteins tagged with maltose binding protein. The region essential for adhesion to porcine intestinal epithelial cells was mapped between amino acid residues 60 and 109 of FedF. To map the binding domain even more closely, all eight charged amino acid residues within this region were independently replaced by alanine. Three of these single point mutants expressing F18 fimbriae exhibited significantly diminished capabilities to adhere to porcine epithelial cells in vitro. In addition, a triple point mutation and a double point mutation completely abolished receptor adhesiveness. The result further confirmed that the region between amino acid residues 60 and 109 is essential for the binding of F18 fimbriae to their receptor. In addition, the adhesion capability of the binding domain was eliminated after treatment with iodoacetamide, suggesting the formation of a disulfide bridge between Cys-63 and Cys-83, whereas Cys-111 and Cys-116 could be deleted without affecting the binding ability of FedF. PMID:12654838

  2. Divergent Evolution of the repFII Replicon of IncF Plasmids Carrying Cytotoxic Necrotizing Factor cnf2, Cytolethal Distending Toxin cdtIII, and f17Ae Fimbrial Variant Genes in Type 2 Necrotoxigenic Escherichia coli Isolates from Calves

    PubMed Central

    Bihannic, Morgan; Haenni, Marisa; Oswald, Eric

    2015-01-01

    Among the pathovars of Escherichia coli in cattle, necrotoxigenic E. coli (NTEC) is defined by the production of cytotoxic necrotizing factors (CNFs). In particular, type 2 NTEC (NTEC2) strains are frequent in diarrheic and septicemic calves and usually coproduce CNF type 2 (CNF2), cytolethal distending toxin type III (CDTIII), and fimbrial adhesins of the F17 family, whose genetic determinants have frequently been reported on the same Vir-like plasmid. In this study, we investigated the genetic environment of the cnf2, f17Ae, and cdtIII genes in a collection of fecal E. coli isolates recovered from 484 French and 58 Iranian calves. In particular, we highlighted the spread of cnf2, f17Ae, and cdtIII on similar 150-kb IncF plasmids harboring the newly assigned repFII replicon allele F74 in NTEC2 isolates. Interestingly, this 150-kb IncF plasmid differed from the 140-kb IncF plasmid harboring the newly assigned repFII replicon allele F75 and carrying cnf2 alone. These results suggest two divergent lineages of cnf2-carrying IncF plasmids depending on the presence of the f17Ae and cdtIII genes. This partition was observed in E. coli strains of unrelated backgrounds, suggesting two different evolutionary paths of cnf2-carrying IncF plasmids rather than divergent evolutions of NTEC2 clones. The driving forces for such divergent evolutions are not known, and further studies are required to clarify the selection of plasmid subtypes spreading virulence determinants in E. coli, in particular, plasmids of the IncF family. PMID:26546422

  3. Molecular screening of pathogenic Escherichia coli strains isolated from dairy neonatal calves in Cordoba province, Argentina.

    PubMed

    Picco, Natalia Y; Alustiza, Fabrisio E; Bellingeri, Romina V; Grosso, María C; Motta, Carlos E; Larriestra, Alejandro J; Vissio, Claudina; Tiranti, Karina I; Terzolo, Horacio R; Moreira, Ana R; Vivas, Adriana B

    2015-01-01

    The aim of this study was to perform a current molecular characterization of bovine pathogenic Escherichia coli strains isolated from random samplings in Argentinean dairy farms. Rectal swabs were obtained from 395 (63.7%) healthy and 225 (36.3%) diarrheic calves, belonging to 45 dairy farms in Cordoba Province, Argentina. E. coli isolates were examined for virulence genes (f5, f41, f17, sta, stb, lt, eae, vt) using PCR and the prevalence of E. coli virulence profiles was spatially described in terms of spatial distribution. A total of 30.1% isolates were found to be positive for at least one of the virulence genes. Depending on the different gene combinations present, 11 virulence profiles were found. Most of the isolates analyzed had a single gene, and no combination of fimbrial and enterotoxin gene was predominant. There was no association between the frequency and distribution of E. coli virulence genes and calf health status. Most of the virulence profiles were compatible with ETEC strains and showed a homogeneous distribution over the sampled area. A clustering pattern for E. coli virulence profiles could not be recognized. This work provides updated information on the molecular characterization of pathogenic E. coli strains from dairy herds in Cordoba, Argentina. These findings would be important to formulate prevention programs and effective therapies for diarrhea in calves caused by E. coli.

  4. Detection of virulence factors of Escherichia coli focused on prevalence of EAST1 toxin in stool of diarrheic and non-diarrheic piglets and presence of adhesion involving virulence factors in astA positive strains.

    PubMed

    Zajacova, Zuzana Sramkova; Konstantinova, Lucie; Alexa, Pavel

    2012-01-27

    Between 2005 and 2009, a total of 800 Escherichia coli strains isolated from piglets with diarrhea were tested for the presence of enteroaggregative heat-stable enterotoxin EAST1, heat-labile (LT) and heat-stable enterotoxins (STa) and shigatoxin (Stx2e) by PCR with the purpose of investigating the present distribution of virulence factors on swine farms in the Czech Republic. The isolates were analyzed for their O-serogroup, fimbrial (K88, K99, 987P, F41, F18) and nonfimbrial adhesins (adhesin involved in diffuse adherence AIDA and porcine attaching and effacing-associated factor PAA). The detection rates of ETEC and STEC isolates were 36.5% and 7.75%, respectively, which implies that ETEC play the major role in E. coli infections in Czech herds. Generally, the most common serotype was O149:K88 which possessed genetic determinants for LT and EAST1. None of the tested E. coli isolates was positive for genes K99, 987P and F41. It was shown that out of 800 E. coli strains isolated from pigs, 277 were EAST1 positive and 74% from the latter were identified as ETEC. Of the fimbrial adhesins, K88 and F18 were commonly detected. Over 80% of K88/EAST1 positive strains possessed the gene for paa. We detected no EAE isolate positive for fimbrial adhesins or PAA and AIDA. The AIDA was more often associated with F18 than with K88. The gene astA was also identified among E. coli isolates of non-diarrheic piglets. We tested rectal swab samples collected from apparently healthy piglets on three farms. On all farms, E. coli astA positive strains (26.66%, 90.00% and 46.66% astA positive animals) were isolated. Our results showed a significantly higher prevalence of astA positive E. coli isolates among apparently healthy piglets in comparison with diarrheic piglets. The question remains as to what is the role of the astA gene in the pathogenesis of porcine colibacillosis and as a virulence factor.

  5. Humoral immune response to Bacteroides gingivalis fimbrial antigen in mice.

    PubMed Central

    Ogawa, T; Shimauchi, H; Kusumoto, Y; Hamada, S

    1990-01-01

    Bacteroides gingivalis fimbrial antigen incorporated into liposomes, but not in Tris-HCl buffer, significantly raised the levels of anti-fimbriae antibodies in serum, particularly of the IgG class, after oral primary and booster immunizations in BALB/c mice. An approximately linear relationship was observed between the dose of fimbrial antigen and the level of fimbriae-specific antibodies produced; antibody production reached its maximum at an immunization dosage of 500 micrograms of fimbriae per mouse. Fimbriae-specific antibody production was enhanced by use of a semi-synthetic adjuvant, a stearoyl derivative of sodium beta-N-acetylglucosaminyl-(1----4)-N-acetylmuramyl-L-alanyl-D-isoglutaminyl-(L) - stearoyl-(D)-meso-diamino-pimelic acid-(D)-amide-D-alanine (GM)-53) in liposomes. High anti-fimbriae antibody levels in serum and saliva were maintained for several months in the mice that had received two orally administered boosters of fimbrial antigen with GM-53 in liposomes. Salivary anti-fimbriae antibody levels, particularly of the IgA class, were markedly raised. PMID:1968885

  6. Nucleotide sequences of two fimbrial major subunit genes, pmpA and ucaA, from canine-uropathogenic Proteus mirabilis strains.

    PubMed

    Bijlsma, I G; van Dijk, L; Kusters, J G; Gaastra, W

    1995-06-01

    Proteus mirabilis strains were isolated from dogs with urinary tract infection (UTI) and fimbriae were prepared from two strains. The N-terminal amino acid sequences of the major fimbrial subunits were determined and both sequences appeared identical to the N-terminal amino acid sequence of a urinary cell adhesin (UCA) (Wray, S. K., Hull, S. I., Cook, R. G., Barrish, J. & Hull, R. A., 1986, Infect Immun 54, 43-49). The genes of two different major fimbrial subunits were cloned using oligonucleotide probes that were designed on the basis of the N-terminal UCA sequence. Nucleotide sequencing revealed the complete ucaA gene of 540 bp (from strain IVB247) encoding a polypeptide of 180 amino acids, including a 22 amino acid signal sequence peptide, and the pmpA (P. mirabilis P-like pili) gene of 549 bp (from strain IVB219) encoding a polypeptide of 183 amino acids, including a 23 amino acid signal sequence. Hybridization experiments gave clear indications of the presence of both kinds of fimbriae in many UTI-related canine P. mirabilis isolates. However, the presence of these fimbriae could not be demonstrated in P. vulgaris or other Proteus-related species. Database analysis of amino acid sequences of major subunit proteins revealed that the UcaA protein shares about 56% amino acid identity with the F17A and F111A major fimbrial subunits from bovine enterotoxigenic Escherichia coli. In turn, the PmpA protein more closely resembled the pyelonephritis-associated pili (Pap)-like major subunit protein from UTI-related E. coli. The evolutionary relationship of UcaA, PmpA and various other fimbrial subunit proteins is presented in a phylogenetic tree.

  7. Direct observation of type 1 fimbrial switching.

    PubMed

    Adiciptaningrum, Aileen M; Blomfield, Ian C; Tans, Sander J

    2009-05-01

    The defining feature of bacterial phase variation is a stochastic 'all-or-nothing' switching in gene expression. However, direct observations of these rare switching events have so far been lacking, obscuring possible correlations between switching events themselves, and between switching and other cellular events, such as division and DNA replication. We monitored the phase variation of type 1 fimbriae in individual Escherichia coli in real time and simultaneously tracked the chromosome replication process. We observed distinctive patterns of fim (fimbriae) expression in multiple genealogically related lineages. These patterns could be explained by a model that combines a single switching event with chromosomal fim replication, as well as the epigenetic inheritance of expressed fim protein and RNA, and their dilution by growth. Analysis of the moment of switching at sub-cell-cycle resolution revealed a correlation between fim switching and cell age, which challenges the traditional idea of phase variation as a random Poissonian phenomenon.

  8. FGL chaperone-assembled fimbrial polyadhesins: anti-immune armament of Gram-negative bacterial pathogens.

    PubMed

    Zavialov, Anton; Zav'yalova, Galina; Korpela, Timo; Zav'yalov, Vladimir

    2007-07-01

    This review summarizes the current knowledge on the structure, function, assembly, and biomedical applications of the family of adhesive fimbrial organelles assembled on the surface of Gram-negative pathogens via the FGL chaperone/usher pathway. Recent studies revealed the unique structural and functional properties of these organelles, distinguishing them from a related family, FGS chaperone-assembled adhesive pili. The FGL chaperone-assembled organelles consist of linear polymers of one or two types of protein subunits, each possessing one or two independent adhesive sites specific to different host cell receptors. This structural organization enables these fimbrial organelles to function as polyadhesins. Fimbrial polyadhesins may ensure polyvalent fastening of bacteria to the host cells, aggregating their receptors and triggering subversive signals that allow pathogens to evade immune defense. The FGL chaperone-assembled fimbrial polyadhesins are attractive targets for vaccine and drug design.

  9. RosE represses Std fimbrial expression in Salmonella enterica serotype Typhimurium

    PubMed Central

    Chessa, Daniela; Winter, Maria G; Nuccio, Sean-Paul; Tükel, Çagla; Bäumler, Andreas J

    2008-01-01

    The Salmonella enterica serotype Typhimurium (S. typhimurium) genome contains a large repertoire of putative fimbrial operons that remain poorly characterized because they are not expressed in vitro. In this study, insertions that induced expression of the putative stdABCD fimbrial operon were identified from a random bank of transposon mutants by screening with immuno-magnetic particles for ligand expression (SIMPLE). Transposon insertions upstream of csgC and lrhA or within dam, setB and STM4463 (renamed rosE) resulted in expression of StdA and its assembly into fimbrial filaments on the cell surface. RosE is a novel negative regulator of Std fimbrial expression as indicated by its repression of a std::lacZ reporter construct and by binding of the purified protein to a DNA region upstream of the stdA start codon. Expression of Std fimbriae in the rosE mutant resulted in increased attachment of S. typhimurium to human colonic epithelial cell lines (T-84 and CaCo-2). A rosE mutant exhibited a reduced ability to compete with virulent S. typhimurium for colonization of murine organs, while no defect was observed when both competing strains carried a stdAB deletion. These data suggest that a tight control of Std fimbrial expression mediated by RosE is required during host pathogen interaction. PMID:18331470

  10. Pathogenicity of Vietnamese enterotoxigenic Escherichia coli strains in colostrum-deprived one-day-old piglets.

    PubMed

    Do, T N; Wilkie, I; Driesen, S J; Fahy, V A; Trott, D J

    2006-03-01

    Preweaning colibacillosis is a major cause of economic loss to the swine industry in Vietnam. The aim of this study was to examine the enteropathogenicity of representative enterotoxigenic Escherichia coli (ETEC) strains obtained during an earlier epidemiologic survey conducted in five provinces in North Vietnam. This included isolates belonging to serotype O8 that produced heat-stable and heat-labile enterotoxins but did not produce any of the recognized fimbriae (F4, F5, F6, F41, F18). In vitro hemagglutination (unique mannose-resistant hemagglutination activity with guinea pig, sheep, human, and chicken red blood cells at 37 degrees C, but not at 18 degrees C) and enterocyte brush border attachment assays suggested that the F- ETEC strains produced an unidentified colonization factor that promoted adherence to the intestinal epithelium. Colostrum-deprived 1-day-old piglets challenged with an F- strain (1-2 x 10(9) bacteria) developed acute watery diarrhea within 4 hours of inoculation and suffered up to 20% weight loss, with comparable severity to piglets challenged with conventional F4 and F5 strains. At necropsy, viable counts and histopathologic examination of intestinal sections demonstrated colonization of the duodenum, jejunum, and ileum by F4-positive strains. In comparison, the F- and F5-positive strains attached exclusively to the ileum. Transmission electron micrographs of negatively stained F- cells grown at 37 degrees C demonstrated the presence of fimbriae. These results confirm the presence of a potentially new pathogenic ETEC fimbrial type in piggeries in Vietnam, with a unique hemagglutination property and attachment characteristics similar to ETEC bearing F5 fimbriae.

  11. Molecular cloning and sequencing of the gene encoding the fimbrial subunit protein of Bacteroides gingivalis.

    PubMed Central

    Dickinson, D P; Kubiniec, M A; Yoshimura, F; Genco, R J

    1988-01-01

    The gene encoding the fimbrial subunit protein of Bacteroides gingivalis 381, fimbrilin, has been cloned and sequenced. The gene was present as a single copy on the bacterial chromosome, and the codon usage in the gene conformed closely to that expected for an abundant protein. The predicted size of the mature protein was 35,924 daltons, and the secretory form may have had a 10-amino-acid, hydrophilic leader sequence similar to the leader sequences of the MePhe fimbriae family. The protein sequence had no marked similarity to known fimbrial sequences, and no homologous sequences could be found in other black-pigmented Bacteroides species, suggesting that fimbrillin represents a class of fimbrial subunit protein of limited distribution. Images PMID:2895100

  12. Additive protective effects of colostral antipili antibodies in calves experimentally infected with enterotoxigenic Escherichia coli.

    PubMed Central

    Contrepois, M G; Girardeau, J P

    1985-01-01

    With oral infection of calves by an enterotoxigenic Escherichia coli strain carrying K99, F41, and FY adhesins, colostrums from cows vaccinated against either K99+F41 or FY did not provide protection, but a mixture of the two colostrums did. The association of antibodies directed against the different adhesins is more effective than antibodies directed against one adhesin alone for colostral protection against enterotoxigenic E. coli carrying several adhesins. PMID:2866162

  13. Importance of Escherichia coli in young beef calves from northwestern Quebec.

    PubMed Central

    Ganaba, R; Bigras-Poulin, M; Fairbrother, J M; Bélanger, D

    1995-01-01

    The objectives of this study were: (i) to investigate the prevalence of Escherichia coli producing F5 (K99), F41, or F165 fimbriae and STa enterotoxin; (ii) to determine serum antibody levels against these fimbriae; (iii) and to examine the association between bacteriological and serological results and the presence of diarrhea, in beef calves from northwestern Quebec. A total of 373 live three to four week old calves and 27 dead calves were sampled between January and March 1991. No isolates positive for F5 were detected in live calves, and only one E. coli producing STa and F41 was isolated. Escherichia coli producing F41-like surface antigens or F165 fimbriae were isolated from 17.43% and 5.63% of live calves, respectively. Antibodies against F5, F41 and F165 were low. Escherichia coli isolates positive for F41-like surface antigen were most often observed in calves born between January and March. No association was found between bacteriological and serological findings, nor between these findings and diarrhea. Calves born from dams vaccinated against E. coli had higher median antibody levels than those born from unvaccinated dams. No E. coli positive for F5 or F41 fimbriae were isolated from dead calves. Escherichia coli with F41-like surface antigen or F165 were found in 55.56% and 11.11% of ileal samples; 4% and 16% of cecal samples, and 0% and 7.4% of colon samples, respectively. Escherichia coli positive for F41-like surface antigen were detected significantly more frequently in the ileum (chi (2)2df = 31.01, p < 0.001). PMID:7704838

  14. Plasticity of fimbrial genotype and serotype within populations of Bordetella pertussis: analysis by paired flow cytometry and genome sequencing.

    PubMed

    Vaughan, Thomas E; Pratt, Catherine B; Sealey, Katie; Preston, Andrew; Fry, Norman K; Gorringe, Andrew R

    2014-09-01

    The fimbriae of Bordetella pertussis are required for colonization of the human respiratory tract. Two serologically distinct fimbrial subunits, Fim2 and Fim3, considered important vaccine components for many years, are included in the Sanofi Pasteur 5-component acellular pertussis vaccine, and the World Health Organization recommends the inclusion of strains expressing both fimbrial serotypes in whole-cell pertussis vaccines. Each of the fimbrial major subunit genes, fim2, fim3, and fimX, has a promoter poly(C) tract upstream of its -10 box. Such monotonic DNA elements are susceptible to changes in length via slipped-strand mispairing in vitro and in vivo, which potentially causes on/off switching of genes at every cell division. Here, we have described intra-culture variability in poly(C) tract lengths and the resulting fimbrial phenotypes in 22 recent UK B. pertussis isolates. Owing to the highly plastic nature of fimbrial promoters, we used the same cultures for both genome sequencing and flow cytometry. Individual cultures of B. pertussis contained multiple fimbrial serotypes and multiple different fimbrial promoter poly(C) tract lengths, which supports earlier serological evidence that B. pertussis expresses both serotypes during infection.

  15. A food-grade fimbrial adhesin FaeG expression system in Lactococcus lactis and Lactobacillus casei.

    PubMed

    Lu, W W; Wang, T; Wang, Y; Xin, M; Kong, J

    2016-03-01

    Enterotoxigenic Escherichia coli (ETEC) infection is the major cause of diarrhea in neonatal piglets. The fimbriae as colonizing factor in the pathogenesis of ETEC constitute a primary target for vaccination against ETEC. Lactic acid bacteria (LAB) are attractive tools to deliver antigens at the mucosal level. With the safety of genetically modified LAB in mind, a food-grade secretion vector (pALRc or pALRb) was constructed with DNA entirely from LAB, including the replicon, promoter, signal peptide, and selection marker alanine racemase gene (alr). To evaluate the feasibility of the system, the nuclease gene (nuc) from Staphylococcus aureus was used as a reporter to be expressed in both Lactococcus lactis and Lactobacillus casei. Subsequently, the extracellular secretion of the fimbrial adhesin FaeG of ETEC was confirmed by Western blot analysis. These results showed that this food-grade expression system has potential as the delivery vehicle for the safe use of genetically modified LAB for the development of vaccines against ETEC infection.

  16. Production and regulation of functional amyloid curli fimbriae by Shiga toxin-producing Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Functional amyloid, in the form of adhesive fimbrial proteins termed curli, was first described in Salmonella and Escherichia coli. Curli fibers adhere to various host cells and structural proteins, interact with components of the host immune system, and participate in biofilm formation. Shiga toxin...

  17. Identification and Characterization of a Gene Cluster Mediating Enteroaggregative Escherichia Coli Aggregative Adherence Fimbria I Biogenesis

    DTIC Science & Technology

    1994-08-01

    adherent E. coli ( DAEC ). respectively. The LA ties to other known fimbrial biogenesis systems of pathogenic pattern is typified by the formation of...agg gene cluster is configured similarly to 60 to 80% of DAEC strains share relatedness with F1845 the determinants of members of the Dr adhesin

  18. Evolution of the Chaperone/Usher Assembly Pathway: Fimbrial Classification Goes Greek†

    PubMed Central

    Nuccio, Sean-Paul; Bäumler, Andreas J.

    2007-01-01

    Summary: Many Proteobacteria use the chaperone/usher pathway to assemble proteinaceous filaments on the bacterial surface. These filaments can curl into fimbrial or nonfimbrial surface structures (e.g., a capsule or spore coat). This article reviews the phylogeny of operons belonging to the chaperone/usher assembly class to explore the utility of establishing a scheme for subdividing them into clades of phylogenetically related gene clusters. Based on usher amino acid sequence comparisons, our analysis shows that the chaperone/usher assembly class is subdivided into six major phylogenetic clades, which we have termed α-, β-, γ-, κ-, π-, and σ-fimbriae. Members of each clade share related operon structures and encode fimbrial subunits with similar protein domains. The proposed classification system offers a simple and convenient method for assigning newly discovered chaperone/usher systems to one of the six major phylogenetic groups. PMID:18063717

  19. Salmonella enterica serotype Typhimurium fimbrial proteins serve as antigens during infection of mice.

    PubMed

    Humphries, Andrea; Deridder, Sandra; Bäumler, Andreas J

    2005-09-01

    The Salmonella enterica serotype Typhimurium genome contains 13 operons with homology to fimbrial gene sequences. Here we investigated the role of 11 serotype Typhimurium fimbrial proteins, including FimA, AgfA (CsgA), BcfA, StbA, SthA, LpfA, PefA, StdA, StcA, StiA, and StfA, as antigens during the infection of genetically resistant mice (CBA). Upon the growth of serotype Typhimurium in standard laboratory broth culture, only the expression of FimA could be detected by Western blot analysis. The infection of mice with serotype Typhimurium grown in broth culture, followed by at least one subsequent infection, resulted in seroconversion of animals to FimA, AgfA, BcfA, StbA, SthA, LpfA, PefA, StdA, StcA, StiA, and StfA positivity. Most animals seroconverted to only a subset of these fimbrial antigens. The immunization of mice with glutathione S-transferase (GST)-FimA, GST-AgfA, GST-BcfA, GST-StbA, GST-SthA, GST-LpfA, GST-PefA, GST-StdA, GST-StcA, GST-StiA, and GST-StfA fusion proteins resulted in reduced fecal shedding of serotype Typhimurium during a challenge compared to that by a control group immunized with purified GST protein. Collectively, these data suggest that the expression of serotype Typhimurium fimbrial antigens is induced during the infection of mice.

  20. Genetic exchange of fimbrial alleles exemplifies the adaptive virulence strategy of Porphyromonas gingivalis.

    PubMed

    Kerr, Jennifer E; Abramian, Jared R; Dao, Doan-Hieu V; Rigney, Todd W; Fritz, Jamie; Pham, Tan; Gay, Isabel; Parthasarathy, Kavitha; Wang, Bing-yan; Zhang, Wenjian; Tribble, Gena D

    2014-01-01

    Porphyromonas gingivalis is a gram-negative anaerobic bacterium, a member of the human oral microbiome, and a proposed "keystone" pathogen in the development of chronic periodontitis, an inflammatory disease of the gingiva. P. gingivalis is a genetically diverse species, and is able to exchange chromosomal DNA between strains by natural competence and conjugation. In this study, we investigate the role of horizontal DNA transfer as an adaptive process to modify behavior, using the major fimbriae as our model system, due to their critical role in mediating interactions with the host environment. We show that P. gingivalis is able to exchange fimbrial allele types I and IV into four distinct strain backgrounds via natural competence. In all recombinants, we detected a complete exchange of the entire fimA allele, and the rate of exchange varies between the different strain backgrounds. In addition, gene exchange within other regions of the fimbrial genetic locus was identified. To measure the biological implications of these allele swaps we compared three genotypes of fimA in an isogenic background, strain ATCC 33277. We demonstrate that exchange of fimbrial allele type results in profound phenotypic changes, including the quantity of fimbriae elaborated, membrane blebbing, auto-aggregation and other virulence-associated phenotypes. Replacement of the type I allele with either the type III or IV allele resulted in increased invasion of gingival fibroblast cells relative to the isogenic parent strain. While genetic variability is known to impact host-microbiome interactions, this is the first study to quantitatively assess the adaptive effect of exchanging genes within the pan genome cloud. This is significant as it presents a potential mechanism by which opportunistic pathogens may acquire the traits necessary to modify host-microbial interactions.

  1. Genetic Exchange of Fimbrial Alleles Exemplifies the Adaptive Virulence Strategy of Porphyromonas gingivalis

    PubMed Central

    Kerr, Jennifer E.; Abramian, Jared R.; Dao, Doan-Hieu V.; Rigney, Todd W.; Fritz, Jamie; Pham, Tan; Gay, Isabel; Parthasarathy, Kavitha; Wang, Bing-yan; Zhang, Wenjian; Tribble, Gena D.

    2014-01-01

    Porphyromonas gingivalis is a gram–negative anaerobic bacterium, a member of the human oral microbiome, and a proposed “keystone” pathogen in the development of chronic periodontitis, an inflammatory disease of the gingiva. P. gingivalis is a genetically diverse species, and is able to exchange chromosomal DNA between strains by natural competence and conjugation. In this study, we investigate the role of horizontal DNA transfer as an adaptive process to modify behavior, using the major fimbriae as our model system, due to their critical role in mediating interactions with the host environment. We show that P. gingivalis is able to exchange fimbrial allele types I and IV into four distinct strain backgrounds via natural competence. In all recombinants, we detected a complete exchange of the entire fimA allele, and the rate of exchange varies between the different strain backgrounds. In addition, gene exchange within other regions of the fimbrial genetic locus was identified. To measure the biological implications of these allele swaps we compared three genotypes of fimA in an isogenic background, strain ATCC 33277. We demonstrate that exchange of fimbrial allele type results in profound phenotypic changes, including the quantity of fimbriae elaborated, membrane blebbing, auto-aggregation and other virulence-associated phenotypes. Replacement of the type I allele with either the type III or IV allele resulted in increased invasion of gingival fibroblast cells relative to the isogenic parent strain. While genetic variability is known to impact host-microbiome interactions, this is the first study to quantitatively assess the adaptive effect of exchanging genes within the pan genome cloud. This is significant as it presents a potential mechanism by which opportunistic pathogens may acquire the traits necessary to modify host-microbial interactions. PMID:24626479

  2. A conserved fold for fimbrial components revealed by the crystal structure of a putative fimbrial assembly protein (BT1062) from Bacteroides thetaiotaomicron at 2.2 Å resolution

    PubMed Central

    Xu, Qingping; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Bakolitsa, Constantina; Cai, Xiaohui; Carlton, Dennis; Chen, Connie; Chiu, Hsiu-Ju; Chiu, Michelle; Clayton, Thomas; Das, Debanu; Deller, Marc C.; Duan, Lian; Ellrott, Kyle; Farr, Carol L.; Feuerhelm, Julie; Grant, Joanna C.; Grzechnik, Anna; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Kumar, Abhinav; Marciano, David; McMullan, Daniel; Miller, Mitchell D.; Morse, Andrew T.; Nigoghossian, Edward; Nopakun, Amanda; Okach, Linda; Puckett, Christina; Reyes, Ron; Sefcovic, Natasha; Tien, Henry J.; Trame, Christine B.; van den Bedem, Henry; Weekes, Dana; Wooten, Tiffany; Yeh, Andrew; Zhou, Jiadong; Hodgson, Keith O.; Wooley, John; Elsliger, Marc-Andre; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.

    2010-01-01

    BT1062 from Bacteroides thetaiotaomicron is a homolog of Mfa2 (PGN0288 or PG0179), which is a component of the minor fimbriae in Porphyromonas gingivalis. The crystal structure of BT1062 revealed a conserved fold that is widely adopted by fimbrial components. PMID:20944223

  3. Phenotypic and genotypic characterization of enterotoxigenic Escherichia coli serotype O8:KX105 and O8:K"2829" strains isolated from piglets with diarrhea.

    PubMed Central

    Broes, A; Fairbrother, J M; Mainil, J; Harel, J; Lariviere, S

    1988-01-01

    Twelve pathogenic and seven nonpathogenic enterotoxigenic Escherichia coli strains which were previously identified as belonging to serogroup O8:KX105 (A. Broes, J. M. Fairbrother, S. Larivière, M. Jacques, and W. M. Johnson, Infect. Immun. 56:241-246, 1988) were further examined for their phenotypic and genotypic properties. Only the 12 pathogenic strains were confirmed to possess the capsular antigen KX105. The seven nonpathogenic strains did not possess this antigen and thus were incorrectly assigned to have capsular antigen KX105. All seven nonpathogenic strains apparently possessed a previously unrecognized capsular antigen which has been designated K"2829". Studies with antisera prepared against F1 (type 1) fimbriae from three E. coli strains suggested that at least three antigenic subtypes of F1 fimbriae were represented among the O8:KX105 strains examined. By using serotyping, biotyping, and outer membrane protein profile analyses, the O8:KX105 strains were divided into at least two distinct clusters, whereas the O8:K"2829" strains were grouped into a single unique cluster. Most of the strains of the same cluster were further differentiated by testing for antibiotic resistance and colicin production and resistance and by analysis of plasmid content. With the exception of one strain which lost its enterotoxicity during storage, all of the O8:KX105 strains hybridized with the gene probes for the heat-labile (LT) and heat-stable (STb) enterotoxins. For each O8:KX105 strain, a single plasmid ranging in size from 61 to 77 megadaltons carried the LT and STb genes.All of the enterotoxigenic O8: KX105 strains fermented sorbose, whereas the nonenterotoxigenic strain did not. All of the O8:K "2829" strains hybridized with the STb probe only. For each O8:K "2829" strain, the STb genes were located on a single plasmid of 61 or 22 megadaltons. None of the strains demonstrated homology with the genes encoding the F4 (K88), F5 (K99), F6 (987P), and F41 fimbrial antigens

  4. Characterization of fimbriae produced by enteropathogenic Escherichia coli.

    PubMed Central

    Girón, J A; Ho, A S; Schoolnik, G K

    1993-01-01

    Enteropathogenic Escherichia coli (EPEC) express rope-like bundles of filaments, termed bundle-forming pili (BFP) (J. A. Girón, A. S. Y. Ho, and G. K. Schoolnik, Science 254:710-713, 1991). Expression of BFP is associated with localized adherence to HEp-2 cells and the presence of the EPEC adherence factor plasmid. In this study, we describe the identification of rod-like fimbriae and fibrillae expressed simultaneously on the bacterial surface of three prototype EPEC strains. Upon fimbrial extraction from EPEC B171 (O111:NM), three fimbrial subunits with masses of 16.5, 15.5, and 14.7 kDa were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Their N-terminal amino acid sequence showed homology with F9 and F7(2) fimbriae of uropathogenic E. coli and F1845 of diffuse-adhering E. coli, respectively. The mixture of fimbrial subunits (called FB171) exhibited mannose-resistant agglutination of human erythrocytes only, and this activity was not inhibited by alpha-D-Gal(1-4)-beta-Gal disaccharide or any other described receptor analogs for P, S, F, M, G, and Dr hemagglutinins of uropathogenic E. coli, which suggests a different receptor specificity. Hemagglutination was inhibited by extracellular matrix glycoproteins, i.e., collagen type IV, laminin, and fibronectin, and to a lesser extent by gangliosides, fetuin, and asialofetuin. Scanning electron microscopic studies performed on clusters of bacteria adhering to HEp-2 cells revealed the presence of structures resembling BFP and rod-like fimbriae linking bacteria to bacteria and bacteria to the eukaryotic cell membrane. We suggest a role of these surface appendages in the interaction of EPEC with eukaryotic cells as well as in the overall pathogenesis of intestinal disease caused by EPEC. Images PMID:7901197

  5. Effectiveness of F18+ Fimbrial Antigens Released by a Novel Autolyzed Salmonella Expression System as a Vaccine Candidate against Lethal F18+ STEC Infection

    PubMed Central

    Won, Gayeon; Lee, John H.

    2016-01-01

    Porcine edema disease (ED) caused by Shiga toxin 2e producing Escherichia coli expressing F18ab+ fimbriae (F18ab+STEC) frequently occurs in post-weaned piglets, resulting in a significant economic loss in swine industries worldwide. In the present study, we proposed an efficient prevention scheme against ED in which the attenuated Salmonella Typhimurium inactivated by the E-mediated cell lysis to deliver target antigens, FedF and FedA, which function in fimbrial-mediated adhesion and as a major subunit of F18ab+fimbriae, respectively. The co-expression of FedA and FedF protein with outer membrane protein A signal peptide was confirmed in the resultant strains JOL1460 and JOL1464 by immunoblot analysis. Immunization with the candidate strains in mice led to the significant generation of immunoglobulin (Ig) G, specific to both antigens and secretory IgA specific to FedF (P < 0.05). The titers of IgG isotypes, IgG1 and IgG2a, used as markers for T-helpers (Th)-2 and Th-1lymphocytes, respectively, also significantly increased in the immunized group (P < 0.05). The increase in CD3+CD4+ T lymphocyte subpopulation and in vitro proliferative activity was observed in in vivo stimulated splenocytes, which indicated the immunostimulatory effect of the candidate strains. Moreover, the immunized mice were completely protected from a lethal challenge against wild-type F18+STEC whereas 28% of mice died in the non-immunized group. This study demonstrated that the inactivated Salmonella system could efficiently release FedF and FedA and induce robust immune responses specific to the target antigens, which is sufficient to protect the mice from the lethal challenge. PMID:27920758

  6. Nerve growth factor promotes survival of septal cholinergic neurons after fimbrial transections.

    PubMed

    Hefti, F

    1986-08-01

    Several findings obtained in recent years suggest that NGF, aside from its well-established function as a neurotrophic factor for peripheral sympathetic and sensory neurons, also has trophic influence on the cholinergic neurons of the basal forebrain. The present study assessed whether NGF was able to affect survival of central cholinergic neurons after axonal transections in adult rats. The septo-hippocampal pathway was transected unilaterally by cutting the fimbria, and animals were implanted with a cannula through which NGF or control solutions were injected intraventricularly over 4 weeks. The lesions reduced the number of large cell bodies, as visualized by Nissl staining in the medial septal nucleus and in the vertical limb of the diagonal band of Broca. Furthermore, in the same nuclei, they reduced the number of cell bodies positively stained for AChE after pretreatment with diisopropylfluorophosphate (a method known to result in reliable identification of cholinergic neurons in the septal area). On lesioned sides, the number of cholinergic cells in medial septal nucleus and the vertical limb of the diagonal band was reduced by 50 +/- 4%, as compared to the number on contralateral sides. On lesioned sides of animals chronically treated with NGF, the number of AChE-positive cells in these areas was reduced only by 12 +/- 6%, as compared to control levels. These findings suggest that fimbrial transections resulted in retrograde degeneration of cholinergic septo-hippocampal neurons and that NGF treatment strongly attenuated this lesion-induced degeneration.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. E. Coli

    MedlinePlus

    ... CDC Cancel Submit Search The CDC E.coli (Escherichia coli) Note: Javascript is disabled or is not supported ... Brand SoyNut Butter Read the Latest E. coli (Escherichia coli) General Information Protect Yourself Learn about E. coli ...

  8. Evolution of Salmonella enterica Virulence via Point Mutations in the Fimbrial Adhesin

    PubMed Central

    Kisiela, Dagmara I.; Chattopadhyay, Sujay; Libby, Stephen J.; Karlinsey, Joyce E.; Fang, Ferric C.; Tchesnokova, Veronika; Kramer, Jeremy J.; Beskhlebnaya, Viktoriya; Samadpour, Mansour; Grzymajlo, Krzysztof; Ugorski, Maciej; Lankau, Emily W.; Mackie, Roderick I.; Clegg, Steven; Sokurenko, Evgeni V.

    2012-01-01

    Whereas the majority of pathogenic Salmonella serovars are capable of infecting many different animal species, typically producing a self-limited gastroenteritis, serovars with narrow host-specificity exhibit increased virulence and their infections frequently result in fatal systemic diseases. In our study, a genetic and functional analysis of the mannose-specific type 1 fimbrial adhesin FimH from a variety of serovars of Salmonella enterica revealed that specific mutant variants of FimH are common in host-adapted (systemically invasive) serovars. We have found that while the low-binding shear-dependent phenotype of the adhesin is preserved in broad host-range (usually systemically non-invasive) Salmonella, the majority of host-adapted serovars express FimH variants with one of two alternative phenotypes: a significantly increased binding to mannose (as in S. Typhi, S. Paratyphi C, S. Dublin and some isolates of S. Choleraesuis), or complete loss of the mannose-binding activity (as in S. Paratyphi B, S. Choleraesuis and S. Gallinarum). The functional diversification of FimH in host-adapted Salmonella results from recently acquired structural mutations. Many of the mutations are of a convergent nature indicative of strong positive selection. The high-binding phenotype of FimH that leads to increased bacterial adhesiveness to and invasiveness of epithelial cells and macrophages usually precedes acquisition of the non-binding phenotype. Collectively these observations suggest that activation or inactivation of mannose-specific adhesive properties in different systemically invasive serovars of Salmonella reflects their dynamic trajectories of adaptation to a life style in specific hosts. In conclusion, our study demonstrates that point mutations are the target of positive selection and, in addition to horizontal gene transfer and genome degradation events, can contribute to the differential pathoadaptive evolution of Salmonella. PMID:22685400

  9. Type IV fimbrial subunit protein ApfA contributes to protection against porcine pleuropneumonia

    PubMed Central

    2012-01-01

    Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae accounts for serious economic losses in the pig farming industry worldwide. We examined here the immunogenicity and protective efficacy of the recombinant type IV fimbrial subunit protein ApfA as a single antigen vaccine against pleuropneumonia, or as a component of a multi-antigen preparation comprising five other recombinant antigens derived from key virulence factors of A. pleuropneumoniae (ApxIA, ApxIIA, ApxIIIA, ApxIVA and TbpB). Immunization of pigs with recombinant ApfA alone induced high levels of specific serum antibodies and provided partial protection against challenge with the heterologous A. pleuropneumoniae serotype 9 strain. This protection was higher than that engendered by vaccination with rApxIVA or rTbpB alone and similar to that observed after immunization with the tri-antigen combination of rApxIA, rApxIIA and rApxIIIA. In addition, rApfA improved the vaccination potential of the penta-antigen mixture of rApxIA, rApxIIA, rApxIIIA, rApxIVA and rTbpB proteins, where the hexa-antigen vaccine containing rApfA conferred a high level of protection on pigs against the disease. Moreover, when rApfA was used for vaccination alone or in combination with other antigens, such immunization reduced the number of pigs colonized with the challenge strain. These results indicate that ApfA could be a valuable component of an efficient subunit vaccine for the prevention of porcine pleuropneumonia. PMID:22240397

  10. Immunoglobulin domains in Escherichia coli and other enterobacteria: from pathogenesis to applications in antibody technologies.

    PubMed

    Bodelón, Gustavo; Palomino, Carmen; Fernández, Luis Ángel

    2013-03-01

    The immunoglobulin (Ig) protein domain is widespread in nature having a well-recognized role in proteins of the immune system. In this review, we describe the proteins containing Ig-like domains in Escherichia coli and enterobacteria, reporting their structural and functional properties, protein folding, and diverse biological roles. In addition, we cover the expression of heterologous Ig domains in E. coli owing to its biotechnological application for expression and selection of antibody fragments and full-length IgG molecules. Ig-like domains in E. coli and enterobacteria are frequently found in cell surface proteins and fimbrial organelles playing important functions during host cell adhesion and invasion of pathogenic strains, being structural components of pilus and nonpilus fimbrial systems and members of the intimin/invasin family of outer membrane (OM) adhesins. Ig-like domains are also found in periplasmic chaperones and OM usher proteins assembling fimbriae, in oxidoreductases and hydrolytic enzymes, ATP-binding cassette transporters, sugar-binding and metal-resistance proteins. The folding of most E. coli Ig-like domains is assisted by periplasmic chaperones, peptidyl-prolyl cis/trans isomerases and disulfide bond catalysts that also participate in the folding of antibodies expressed in this bacterium. The technologies for expression and selection of recombinant antibodies in E. coli are described along with their biotechnological potential.

  11. AFA and F17 adhesins produced by pathogenic Escherichia coli strains in domestic animals.

    PubMed

    Le Bouguénec, C; Bertin, Y

    1999-01-01

    AFA and F17 are afimbrial and fimbrial adhesins, respectively, produced by pathogenic Escherichia coli strains in domestic animals. F17-related fimbriae are mainly detected on bovine and ovine E. coli associated with diarrhoea or septicaemia. The F17-G adhesin subunits recognize N-acetyl-D-glucosamine (GlcNAc) receptors present on bovine intestinal cells. Some F17 subtypes also bind to GlcNAc receptors present on human uroepithelial and intestinal Caco-2 cells or to the laminin contained in the basement of mammalian membranes. F17 is often associated with other virulence factors (aerobactin, serum resistance, CNF2 toxin, K99, CS31A or AFA adhesins) on pathogenic E. coli. A cluster of only four genes is required to synthesize functional F17-related fimbrial structures. The hypothesis of multifunctional F17 fimbrial subunits is supported by the fact that: i) the N-terminal part of the adhesin subunit participates in receptor recognition, whereas the C-terminal part is required for biogenesis of the fimbrial filament; and ii) the interaction between structural and adhesin subunits seems to be crucial for the initiation of monomer polymerization. Recently, determinants related to the afa gene clusters from human pathogenic E. coli associated with intestinal and extra-intestinal infections were identified in strains isolated from calves and piglets with diarrhoea and septicaemia. Two afa-related gene clusters, designated afa-7 and afa-8, that encode afimbrial adhesins were cloned and characterized from bovine pathogenic E. coli. These animal afa gene clusters were plasmid and chromosome borne and were expressed by strains that produced other virulence factors such as CNF toxins, F17, PAP and CS31A adhesins. A high frequency of afa-8 and a low prevalence of afa-7 among bovine E. coli isolates were suggested by preliminary epidemiological studies. As with the human afa gene clusters, the animal ones encode an adhesive structure composed of two proteins: AfaE which

  12. Vaccines for preventing enterotoxigenic Escherichia coli infections in farm animals.

    PubMed

    Moon, H W; Bunn, T O

    1993-01-01

    Fimbrial vaccines are routinely given parenterally to pregnant cattle, sheep and swine to protect suckling newborn calves, lambs and pigs against enterotoxigenic Escherichia coli (ETEC) infections. Such vaccines are practical and effective because (1) most fatal ETEC infections in farm animals occur in the early neonatal period when the antibody titres in colostrum and milk are highest; (2) more than 90% of the ETEC in farm animals belong to a small family of fimbrial antigen types; (3) fimbriae consist of good protein antigens on the bacterial surface where they are readily accessible to antibody; (4) fimbriae are required for a critical step (adhesion-colonization) early in the pathogenesis of the disease. ETEC infections continue to be a significant clinical problem in farm animals in spite of extensive use of fimbriae-based vaccines. Definitive data on the efficacy of the commercial vaccines in field use are not available. The prevailing perception among animal health professionals is that the vaccines are effective, that the problem occurs chiefly among non-vaccinated animals, and that in some herds vaccination moves peak prevalence of disease from the first to the second or third week after birth, when mortality is lower. It has been suggested that extensive use of vaccines will rapidly select for the emergence of novel or previously low prevalence fimbrial antigen types. There is no evidence that this has happened after a decade of routine vaccine use in the United States. However, there is no active direct surveillance for such emergence.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. S-Fimbria-Encoding Determinant sfaI Is Located on Pathogenicity Island III536 of Uropathogenic Escherichia coli Strain 536

    PubMed Central

    Dobrindt, Ulrich; Blum-Oehler, Gabriele; Hartsch, Thomas; Gottschalk, Gerhard; Ron, Eliora Z.; Fünfstück, Reinhard; Hacker, Jörg

    2001-01-01

    The sfaI determinant encoding the S-fimbrial adhesin of uropathogenic Escherichia coli strains 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 the E. 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 an E. coli K-12-specific genomic island. PMID:11401961

  14. K88 Fimbrial Adhesin Targeting of Microspheres Containing Gentamicin Made with Albumin Glycated with Lactose

    PubMed Central

    Sarabia-Sainz, Andre-i; Sarabia-Sainz, Hector Manuel; Ramos-Clamont Montfort, Gabriela; Mata-Haro, Veronica; Guzman-Partida, Ana María; Guzman, Roberto; Garcia-Soto, Mariano; Vazquez-Moreno, Luz

    2015-01-01

    The formulation and characterization of gentamicin-loaded microspheres as a delivery system targeting enterotoxigenic Escherichia coli K88 (E. coli K88) was investigated. Glycated albumin with lactose (BSA-glucose-β (4-1) galactose) was used as the microsphere matrix (MS-Lac) and gentamicin included as the transported antibiotic. The proposed target strategy was that exposed galactoses of MS-Lac could be specifically recognized by E. coli K88 adhesins, and the delivery of gentamicin would inhibit bacterial growth. Lactosylated microspheres (MS-Lac1, MS-Lac2 and MS-Lac3) were obtained using a water-in-oil emulsion, containing gentamicin, followed by crosslinking with different concentrations of glutaraldehyde. Electron microscopy displayed spherical particles with a mean size of 10–17 µm. In vitro release of gentamicin from MS-Lac was best fitted to a first order model, and the antibacterial activity of encapsulated and free gentamicin was comparable. MS-Lac treatments were recognized by plant galactose-specific lectins from Ricinus communis and Sophora japonica and by E. coli K88 adhesins. Results indicate MS-Lac1, produced with 4.2 mg/mL of crosslinker, as the best treatment and that lactosylated microsphere are promising platforms to obtain an active, targeted system against E. coli K88 infections. PMID:26389896

  15. K88 Fimbrial Adhesin Targeting of Microspheres Containing Gentamicin Made with Albumin Glycated with Lactose.

    PubMed

    Sarabia-Sainz, Andre-I; Sarabia-Sainz, Hector Manuel; Montfort, Gabriela Ramos-Clamont; Mata-Haro, Veronica; Guzman-Partida, Ana María; Guzman, Roberto; Garcia-Soto, Mariano; Vazquez-Moreno, Luz

    2015-09-16

    The formulation and characterization of gentamicin-loaded microspheres as a delivery system targeting enterotoxigenic Escherichia coli K88 (E. coli K88) was investigated. Glycated albumin with lactose (BSA-glucose-β (4-1) galactose) was used as the microsphere matrix (MS-Lac) and gentamicin included as the transported antibiotic. The proposed target strategy was that exposed galactoses of MS-Lac could be specifically recognized by E. coli K88 adhesins, and the delivery of gentamicin would inhibit bacterial growth. Lactosylated microspheres (MS-Lac1, MS-Lac2 and MS-Lac3) were obtained using a water-in-oil emulsion, containing gentamicin, followed by crosslinking with different concentrations of glutaraldehyde. Electron microscopy displayed spherical particles with a mean size of 10-17 µm. In vitro release of gentamicin from MS-Lac was best fitted to a first order model, and the antibacterial activity of encapsulated and free gentamicin was comparable. MS-Lac treatments were recognized by plant galactose-specific lectins from Ricinus communis and Sophora japonica and by E. coli K88 adhesins. Results indicate MS-Lac1, produced with 4.2 mg/mL of crosslinker, as the best treatment and that lactosylated microsphere are promising platforms to obtain an active, targeted system against E. coli K88 infections.

  16. The Bordetella avium BAV1965-1962 fimbrial locus is regulated by temperature and produces fimbriae involved in adherence to turkey tracheal tissue.

    PubMed

    Loker, Stewart B; Temple, Louise M; Preston, Andrew

    2011-06-01

    Bordetella pertussis, Bordetella parapertussis, and Bordetella bronchiseptica cause respiratory tract disease in mammals, whereas Bordetella avium causes respiratory tract disease in avian hosts. While there are striking similarities between the diseases caused by the mammalian- and avian-adapted bordetellae, differences at the genetic level may account for their different host tropisms. Bacterial pathogens utilize the chaperone-usher pathway to assemble extracellular multisubunit structures (fimbriae) that play a role in virulence. Fimbriae of the mammalian bordetellae mediate attachment to the host respiratory epithelium. They are assembled by a single chaperone/usher system encoded by the fimbrial biogenesis operon fimA-D. B. avium contains a homologous fimbrial operon (BAV1965-1962), and we report here the functionality of this locus. Reverse transcription (RT)-PCR and quantitative PCR analyses demonstrated that transcription of the locus is regulated by temperature. By immuno-transmission electron microscopy (TEM), BAV1965-containing fimbriae were observed on bacteria grown at 37°C but not those grown at 22°C. A mutant in which BAV1965-1962 was deleted displayed significantly lower levels of adherence to turkey tracheal rings than the wild type. Thus, the BAV1965-1962 fimbrial locus is functional, its expression is regulated in response to temperature, and it produces fimbriae involved in adherence to host respiratory tract tissue.

  17. E. Coli

    MedlinePlus

    ... Emergency Room? What Happens in the Operating Room? E. Coli KidsHealth > For Kids > E. Coli A A A What's in this article? What ... Doctor Do? What Can Kids Do? en español E. coli What Is It? E. coli is a common ...

  18. Design and Evaluation of a Multiplex PCR Assay for the Simultaneous Identification of Genes for Nine Different Virulence Factors Associated with Escherichia coli that Cause Diarrhea and Edema Disease in Swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multiplex PCR assay was developed for detection and characterization of pathogenic E. coli that cause diarrhea and Edema Disease in swine. This PCR assay was designed as a single reaction for detecting five different adhesins (K88, K99, 987P, F41 and F18), three enterotoxins (LT, STaP, STb), and ...

  19. Escherichia coli Global Gene Expression in Urine from Women with Urinary Tract Infection

    PubMed Central

    Rasko, David A.; Faerber, Gary J.; Mobley, Harry L. T.

    2010-01-01

    Murine models of urinary tract infection (UTI) have provided substantial data identifying uropathogenic E. coli (UPEC) virulence factors and assessing their expression in vivo. However, it is unclear how gene expression in these animal models compares to UPEC gene expression during UTI in humans. To address this, we used a UPEC strain CFT073-specific microarray to measure global gene expression in eight E. coli isolates monitored directly from the urine of eight women presenting at a clinic with bacteriuria. The resulting gene expression profiles were compared to those of the same E. coli isolates cultured statically to exponential phase in pooled, sterilized human urine ex vivo. Known fitness factors, including iron acquisition and peptide transport systems, were highly expressed during human UTI and support a model in which UPEC replicates rapidly in vivo. While these findings were often consistent with previous data obtained from the murine UTI model, host-specific differences were observed. Most strikingly, expression of type 1 fimbrial genes, which are among the most highly expressed genes during murine experimental UTI and encode an essential virulence factor for this experimental model, was undetectable in six of the eight E. coli strains from women with UTI. Despite the lack of type 1 fimbrial expression in the urine samples, these E. coli isolates were generally capable of expressing type 1 fimbriae in vitro and highly upregulated fimA upon experimental murine infection. The findings presented here provide insight into the metabolic and pathogenic profile of UPEC in urine from women with UTI and represent the first transcriptome analysis for any pathogenic E. coli during a naturally occurring infection in humans. PMID:21085611

  20. Novel architectural features of Bordetella pertussis fimbrial subunit promoters and their activation by the global virulence regulator BvgA

    PubMed Central

    Chen, Qing; Decker, Kimberly Baxter; Boucher, Philip E.; Hinton, Deborah; Stibitz, Scott

    2010-01-01

    SUMMARY A prominent feature of the promoters of Bordetella pertussis fimbrial subunit genes fim2, fim3, and fimX is the presence of a “C-stretch”, a monotonic run of C residues. The C-stretch renders these genes capable of phase-variation, through spontaneous variations in its length. For each of these we determined the length of the C-stretch that gave maximal transcriptional activity, and found that the three optimized promoters align perfectly, with identical distances between conserved upstream sequences and the downstream −10 elements and transcriptional start sites. We also demonstrated, for Pfim3, that the conserved sequence corresponds to BvgA-binding sites. The more upstream of the two binding sites is predicted to be high affinity, by comparison to a functionally-derived consensus BvgA-binding sequence. The other binding site is a fairly poor match to this consensus, with 10 of 14 bp belonging to the C-stretch. Interestingly, the center of this downstream site of BvgA binding coincides exactly with the center of the expected typical location of a −35 sequence. However, the lack of a recognizable −35 element (CCCCCC vs. TTGACA), and the occupation of this site by BvgA~P suggest that activation of the fim promoters involves unusual interactions among BvgA, RNA polymerase, and promoter DNA. PMID:20662776

  1. Reduction of Salmonella Enteritidis in the Spleens of Hens by Bacterins That Vary in Fimbrial Protein SefD

    PubMed Central

    Sanchez-Ingunza, Roxana; Morales, Cesar A.; Icard, Alan H.

    2015-01-01

    Abstract The objective of this research was to determine whether variation in the presence of fimbrial protein SefD would impact efficacy of bacterins as measured by recovery of Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) from the spleens of hens. Two bacterins were prepared that varied in SefD content. Also, two adjuvants were tested, namely, water-in-oil and aluminum hydroxide gel (alum). Control groups for both adjuvant preparations included infected nonvaccinated hens and uninfected nonvaccinated hens. At 21 days postinfection, Salmonella Enteritidis was recovered from 69.7%, 53.1%, and 86.0% from the spleens of all hens vaccinated with bacterins lacking SefD, bacterins that included SefD, and infected nonvaccinated control hens, respectively. No Salmonella was recovered from uninfected nonvaccinates. Results from individual trials showed that both bacterins reduced positive spleens, but that the one with SefD was more efficacious. Alum adjuvant had fewer side effects on hens and egg production as compared to water-in-oil. However, adjuvant did not change the relative recovery of Salmonella Enteritidis from spleens. These results suggest that SefD is a promising target antigen for improving the efficacy of immunotherapy in hens, and is intended to reduce Salmonella Enteritidis in the food supply. PMID:26218804

  2. Reduction of Salmonella Enteritidis in the spleens of hens by bacterins that vary in fimbrial protein SefD.

    PubMed

    Sanchez-Ingunza, Roxana; Guard, Jean; Morales, Cesar A; Icard, Alan H

    2015-10-01

    The objective of this research was to determine whether variation in the presence of fimbrial protein SefD would impact efficacy of bacterins as measured by recovery of Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) from the spleens of hens. Two bacterins were prepared that varied in SefD content. Also, two adjuvants were tested, namely, water-in-oil and aluminum hydroxide gel (alum). Control groups for both adjuvant preparations included infected nonvaccinated hens and uninfected nonvaccinated hens. At 21 days postinfection, Salmonella Enteritidis was recovered from 69.7%, 53.1%, and 86.0% from the spleens of all hens vaccinated with bacterins lacking SefD, bacterins that included SefD, and infected nonvaccinated control hens, respectively. No Salmonella was recovered from uninfected nonvaccinates. Results from individual trials showed that both bacterins reduced positive spleens, but that the one with SefD was more efficacious. Alum adjuvant had fewer side effects on hens and egg production as compared to water-in-oil. However, adjuvant did not change the relative recovery of Salmonella Enteritidis from spleens. These results suggest that SefD is a promising target antigen for improving the efficacy of immunotherapy in hens, and is intended to reduce Salmonella Enteritidis in the food supply.

  3. Conservation of an Actinomyces viscosus T14V type 1 fimbrial subunit homolog among divergent groups of Actinomyces spp.

    PubMed Central

    Yeung, M K

    1992-01-01

    The type 1 fimbrial subunit gene of the human Actinomyces viscosus T14V was used as a DNA probe in Southern analyses to detect related DNA sequences in 16 of 30 strains of Actinomyces spp. under conditions of high stringency. The organisms with homology to the DNA probe included two human and six nonhuman A. viscosus, three human and three nonhuman A. naeslundii, and two A. bovis isolates. Homologous DNA sequences were not detected in strains of A. odontolyticus and A. israelii examined in this study. Northern (RNA) blot analysis revealed expression of a transcript from each of the A. viscosus and A. naeslundii strains and from one A. bovis strain that was comparable in size to that detected from A. viscosus T14V. Cell surface fimbriae were observed on a majority of the strains that expressed the transcript. Various degrees of cross-immunoreactivities between these strains and antibodies specific for type 1 fimbriae of A. viscosus T14V were also observed by colony immunoassay. Thus, the data clearly demonstrate the existence in, and expression by, divergent Actinomyces groups of genomic sequences that are closely related to the type 1 fimbriae of A. viscosus T14V. Images PMID:1347285

  4. Putative glycoprotein and glycolipid polymorphonuclear leukocyte receptors for the Actinomyces naeslundii WVU45 fimbrial lectin.

    PubMed Central

    Sandberg, A L; Ruhl, S; Joralmon, R A; Brennan, M J; Sutphin, M J; Cisar, J O

    1995-01-01

    Recognition of receptors on sialidase-treated polymorphonuclear leukocytes (PMNs) by the Gal/GalNAc lectin associated with the type 2 fimbriae of certain strains of actinomyces results in activation of the PMNs, phagocytosis, and destruction of the bacteria. In the present study, plant lectins were utilized as probes to identify putative PMN receptors for the actinomyces lectin. The Gal-reactive lectin from Ricinus communis (RCAI), the Gal/GalNAc-reactive lectins from R. communis (RCAII) and Bauhinia purpurea (BPA), as well as the Gal beta 1-3GalNAc-specific lectins from Arachis hypogaea (PNA) and Agaricus bisporus (ABA) inhibited killing of Actinomyces naeslundii WVU45 by sialidase-treated PMNs. These five lectins detected a 130-kDa surface-labeled glycoprotein on nitrocellulose transfers of PMN extracts separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This glycoprotein was revealed only after treatment of the transfers with sialidase, a condition analogous to the sialidase dependence of the lectin-mediated biological responses of the PMNs to the actinomyces. The mannose-reactive lectin concanavalin A did not inhibit killing of the actinomyces and failed to detect the 130-kDa glycoprotein but did block PMN-dependent killing of Escherichia coli B, a bacterium that possesses mannose-sensitive fimbriae. Therefore, the PMN glycoprotein receptor for A. naeslundii is clearly distinct from those recognized by E. coli. Two major putative glycolipid receptors were also identified by actinomyces and RCAI overlays on sialidase-treated thin-layer chromatograms of PMN gangliosides. Thus, both a 130-kDa glycoprotein and certain gangliosides are implicated in the attachment of the actinomyces to PMNs. PMID:7790078

  5. Immune response in diarrheal patients and asymptomatic carrier with CS6-producing enterotoxigenic Escherichia coli infection.

    PubMed

    Puiprom, Orapim; Chantaroj, Siriporn; Matsuda, Shigeaki; Sawanpanyalert, Pathom; Honda, Takeshi; Iida, Tetsuya; Taniguchi, Tooru

    2012-11-01

    Enterotoxigenic Escherichia coli (ETEC) is one of the major causes of diarrhea in children and travelers in developing countries. ETEC colonization factors (CFs) are virulence determinants considered as protective antigens and major targets for vaccine development against ETEC infections. One of the most prevalent CFs, coli surface antigen 6 (CS6), a non-fimbrial polymeric protein consisting of two major subunits, CssA and CssB, is produced by approximately 25-35% of ETEC worldwide. We could isolate only CS6-producing ETEC strains from two diarrheal patients and one asymptomatic carrier, but we could not detect CssA- or CssB-specific antibodies in the feces and blood of two patients convalescing from natural ETEC infection and of an asymptomatic carrier using western blotting. Therefore, in order to protect against infection with CS6-producing ETEC, protective levels of CS6 immunity should be incorporated in any future vaccines against ETEC.

  6. The role of genomic islands in Escherichia coli K1 interactions with intestinal and kidney epithelial cells.

    PubMed

    Yousuf, Farzana Abubakar; Rafiq, Sahar; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2016-04-01

    The completion of Escherichia coli K1 genome has identified several genomic islands that are present in meningitis-causing E. coli RS218 but absent in the non-pathogenic E. coli MG1655. In this study, the role of various genomic islands in E. coli K1 interactions with intestinal epithelial cells (Caco-2) and kidney epithelial cells (MA104) was determined. Using association assays, invasion assays, and intracellular survival assays, the findings revealed that the genomic island deletion mutants of RS218 related to P fimbriae, S fimbriae, F17-like fimbriae, non-fimbrial adhesins, Hek and hemagglutinin, protein secretion system (T1SS for hemolysin; T2SS; T5SS for antigen 43), Iro system and hmu system), invasins (CNF1, IbeA), toxins (α-hemolysin), K1 capsule biosynthesis, metabolism (d-serine catabolism, dihydroxyacetone, glycerol, and glyoxylate metabolism), prophage genes, showed reduced interactions with both cell types. Next, we determined the role of various genomic islands in E. coli K1 resistance to serum. When exposed to the normal human serum, the viability of the genomic island deletion mutants related to adhesins such as S fimbriae, P fimbriae, F17-like fimbriae, non-fimbrial adhesins, Hek and hemagglutinin, antigen 43 and T5SS for antigen 43, T2SS, and T1SS for hemolysin, Iro system and hmu system, prophage genes, metabolism (sugar metabolism and d-serine catabolism), K1 capsule biosynthesis, and invasins such as CNF1 was affected, suggesting their role in bacteremia. The characterization of these genomic islands should reveal mechanisms of E. coli K1 pathogenicity that could be of value as therapeutic targets.

  7. Structural predictions of AgfA, the insoluble fimbrial subunit of Salmonella thin aggregative fimbriae.

    PubMed

    Collinson, S K; Parker, J M; Hodges, R S; Kay, W W

    1999-07-16

    The unusually stable and multifunctional, thin aggregative fimbriae common to all Salmonella spp. are principally polymers of the fimbrin subunit, AgfA. AgfA of Salmonella enteritidis consists of two domains: a protease-sensitive, 22 amino acid residue N-terminal region and a protease-resistant, 109 residue C-terminal core. The unusual amino acid sequence of the AgfA core region comprises two-, five- and tenfold internal sequence homology patterns reflected in five conserved, 18-residue tandem repeats. These repeats have the consensus sequence, Sx5QxGx2NxAx3Q and are linked together by four or five residues, (x)xAx2. The predicted secondary structure for this unusual arrangement of tandem repeats in AgfA indicates mainly extended conformation with the beta strands linked by four to six residues. Candidate proteins of known structure with motifs of alternating beta strands and short loops were selected from folds described in SCOP as a source of coordinates for AgfA model construction. Three all-beta class motifs selected from the Serratia marcescens metalloprotease, myelin P2 protein or vitelline membrane outer protein I were used for initial AgfA homology build-up procedures ultimately resulting in three structural models; beta barrel, beta prism and parallel beta helix. The beta barrel model is a compact, albeit irregular structure, with the beta strands arranged in two antiparallel beta sheet faces. The beta prism model does not reflect the 5 or 10-fold symmetry of the AgfA primary sequence. However, the favored, parallel beta helix model is a compact coil of ten helically arranged beta strands forming two parallel beta sheet faces. This arrangement predicts a regular, potentially stable, C-terminal core region consistent with the observed tandem repeat sequences, protease-resistance and strong tendency of this fimbrin to oligomerize and aggregate. Positional conservation of amino acid residues in AgfA and the Escherichia coli AgfA homologue, CsgA, provides

  8. A systematic review and meta-analysis of the epidemiology of pathogenic Escherichia coli of calves and the role of calves as reservoirs for human pathogenic E. coli.

    PubMed

    Kolenda, Rafał; Burdukiewicz, Michał; Schierack, Peter

    2015-01-01

    Escherichia coli bacteria are the most common causes of diarrhea and septicemia in calves. Moreover, calves form a major reservoir for transmission of pathogenic E. coli to humans. Systematic reviews and meta-analyses of publications on E. coli as calf pathogens and the role of calves as reservoir have not been done so far. We reviewed studies between 1951 and 2013 reporting the presence of virulence associated factors (VAFs) in calf E. coli and extracted the following information: year(s) and country of sampling, animal number, health status, isolate number, VAF prevalence, serotypes, diagnostic methods, and biological assays. The prevalence of VAFs or E. coli pathotypes was compared between healthy and diarrheic animals and was analyzed for time courses. Together, 106 papers with 25,982 E. coli isolates from 27 countries tested for VAFs were included. F5, F17, and F41 fimbriae and heat-stable enterotoxin (ST) - VAFs of enterotoxigenic E. coli (ETEC) were significantly associated with calf diarrhea. On the contrary, ETEC VAF F4 fimbriae and heat-labile enterotoxin as well as enteropathogenic (EPEC), Shiga toxin-producing (STEC), and enterohemorrhagic E. coli (EHEC) were not associated with diarrhea. The prevalence increased overtime for ST-positive isolates, but decreased for F5- and STEC-positive isolates. Our study provides useful information about the history of scientific investigations performed in this domain so far, and helps to define etiological agents of calf disease, and to evaluate calves as reservoir hosts for human pathogenic E. coli.

  9. Uropathogenic virulence factor FimH facilitates binding of uteropathogenic Escherichia coli to canine endometrium.

    PubMed

    Krekeler, N; Marenda, M S; Browning, G F; Holden, K M; Charles, J A; Wright, P J

    2012-09-01

    Pyometra is a potentially life-threatening condition in bitches and is often caused by Escherichia coli infection. Both pathogenic and non-pathogenic E. coli strains commonly carry the genes for type 1 fimbriae that mediate bacterial adhesion onto host epithelium. To investigate whether the type 1 fimbrial adhesin, FimH, facilitates the binding of uropathogenic E. coli to canine endometrium, the fimH gene was insertionally inactivated in a pathogenic E. coli strain. The ability of E. coli to bind to canine endometrial epithelial cells was determined in vitro using canine uterine biopsies. Binding of the fimH mutant was only 0.3% of that of the wild type. Complementation of the mutation restored the phenotype to that of the parent. This study has developed an in vitro model that allows quantitative and qualitative assessment of bacterial binding to canine endometrium and has demonstrated that the fimH gene plays a role in adherence of pathogenic E. coli to canine endometrium.

  10. E. Coli

    MedlinePlus

    ... of Your Teeth El cuidado de los dientes Video: Getting an X-ray E. Coli KidsHealth > For Kids > E. Coli Print A A A What's in ... recalls affecting contaminated vegetables or other products. But kids can ... inside. Don't swallow lake, ocean, or pool water. If the water contains ...

  11. Detection and sequences of the enteroaggregative Escherichia coli heat-stable enterotoxin 1 gene in enterotoxigenic E. coli strains isolated from piglets and calves with diarrhea.

    PubMed

    Yamamoto, T; Nakazawa, M

    1997-01-01

    Enterotoxigenic Escherichia coli (ETEC) strains isolated from piglets and calves with diarrhea were tested for the presence of the enteroaggregative E. coli enterotoxin 1 (EAST1) gene sequences by PCR and colony hybridization. The EAST1 gene was found in most porcine ETEC strains with adherence factor K88, especially in those elaborating heat-labile enterotoxin. One porcine ETEC strain with adherence factor K99 was also positive for the EAST1 gene. In contrast, 987P-positive (987P+) ETEC strains from piglets, K99+ ETEC strains from calves, and K99+ F41+ or F41+ ETEC strains from piglets and calves were negative for the EAST1 gene. The K88ab+ or K88ac+ ETEC strains tested possessed the EAST1 gene on a plasmid that was distinct from a K88-encoding plasmid. The EAST1 gene sequences of the K88+ ETEC strains were identical to each other and 99.1 and 98.3% homologous to the previously reported sequences of ETEC strains colonizing humans and enteroaggregative E. coli strains, respectively. The data indicate that the EAST1 gene is distributed among porcine ETEC strains in association with the adherence factor type.

  12. E. Coli Infection

    MedlinePlus

    ... is E. coli?E. coli is short for Escherichia coli -- bacteria (germs) that cause severe cramps and diarrhea. ... staff Tags: bacterial endotoxin, bloody diarrhea, enterohemorrhagic infection, Escherichia coli, food-borne illness, gastroenteritis, hemorrhagic colitis, HUS, thrombotic ...

  13. Regulation of type 1 fimbriae synthesis and biofilm formation by the transcriptional regulator LrhA of Escherichia coli.

    PubMed

    Blumer, Caroline; Kleefeld, Alexandra; Lehnen, Daniela; Heintz, Margit; Dobrindt, Ulrich; Nagy, Gábor; Michaelis, Kai; Emödy, Levente; Polen, Tino; Rachel, Reinhard; Wendisch, Volker F; Unden, Gottfried

    2005-10-01

    Type 1 fimbriae of Escherichia coli facilitate attachment to the host mucosa and promote biofilm formation on abiotic surfaces. The transcriptional regulator LrhA, which is known as a repressor of flagellar, motility and chemotaxis genes, regulates biofilm formation and expression of type 1 fimbriae. Whole-genome expression profiling revealed that inactivation of lrhA results in an increased expression of structural components of type 1 fimbriae. In vitro, LrhA bound to the promoter regions of the two fim recombinases (FimB and FimE) that catalyse the inversion of the fimA promoter, and to the invertible element itself. Translational lacZ fusions with these genes and quantification of fimE transcript levels by real-time PCR showed that LrhA influences type 1 fimbrial phase variation, primarily via activation of FimE, which is required for the ON-to-OFF transition of the fim switch. Enhanced type 1 fimbrial expression as a result of lrhA disruption was confirmed by mannose-sensitive agglutination of yeast cells. Biofilm formation was stimulated by lrhA inactivation and completely suppressed upon LrhA overproduction. The effects of LrhA on biofilm formation were exerted via the changed levels of surface molecules, most probably both flagella and type 1 fimbriae. Together, the data show a role for LrhA as a repressor of type 1 fimbrial expression, and thus as a regulator of the initial stages of biofilm development and, presumably, bacterial adherence to epithelial host cells also.

  14. Effect of 2,4-Dichlorophenoxyacetic acid herbicide Escherichia coli growth, chemical, composition, and cellular envelope

    USGS Publications Warehouse

    Carr, R.S.; Biedenbach, J.M.; Hooten, R.L.

    2001-01-01

    2,4-Dichlorophenoxyacetic acid (2,4-D) is a herbicide widely used in the world and mainly excreted by the renal route in exposed humans and animals. Herbicides can affect other nontarget organisms, such as Escherichia coli. We observed that a single exposure to 1 mM 2,4-D diminished growth and total protein content in all E. coli strains tested in vitro. In addition, successive exposures to 0.01 mM 2,4-D had a toxic effect decreasing growth up to early stationary phase. Uropathogenic E. coli adhere to epithelial cells mediated by fimbriae, adhesins, and hydrophobic properties. 2,4-D exposure of uropathogenic E. coli demonstrated altered hydrophobicity and fimbriation. Hydrophobicity index values obtained by partition in p-xylene/water were 300-420% higher in exposed cells than in control ones. Furthermore, values of hemagglutination titer, protein contents in fimbrial crude extract, and electron microscopy demonstrated a significant diminution of fimbriation in treated cells. Other envelope alterations could be detected, such as lipoperoxidation, evidenced by decreased polyunsaturated fatty acids and increased lipid degradation products (malonaldehyde), and motility diminution. These alterations decreased cell adherence to erythrocytes, indicating a diminished pathogenic capacity of the 2,4-D-exposed E. coli. ?? 2001 by John Wiley & Sons, Inc.

  15. Avirulent K88 (F4)+ Escherichia coli strains constructed to express modified enterotoxins protect young piglets from challenge with a virulent enterotoxigenic Escherichia coli strain that expresses the same adhesion and enterotoxins.

    PubMed

    Santiago-Mateo, Kristina; Zhao, Mojun; Lin, Jun; Zhang, Weiping; Francis, David H

    2012-10-12

    Virulence of enterotoxigenic Escherichia coli (ETEC) is associated with fimbrial adhesins and enterotoxins such as heat-labile (LT) and/or heat-stable (ST) enterotoxins. Previous studies using a cell culture model suggest that exclusion of ETEC from attachment to epithelial cells requires expression of both an adhesin such as K88 (F4) fimbriae, and LT. To test the ability of non-pathogenic E. coli constructs to exclude virulent ETEC sufficiently to prevent clinical disease, we utilized a piglet ETEC challenge model. Thirty-nine 5-day-old piglets were inoculated with a placebo (control), or with either of the three K88(+)E. coli strains isogenic with regard to modified LT expression: 8017 (pBR322 plasmid vector control), non-toxigenic mutant 8221 (LT(R192G)) in pBR322, or 8488, with the LT gene fused to the STb gene in pBR322 (LT(R192G)-STb). Piglets were challenged with virulent ETEC Strain 3030-2 (K88(+)/LT/STb) 24h post-inoculation. K88ac receptor-positive piglets in the control group developed diarrhea and became dehydrated 12-24h post-challenge. Piglets inoculated with 8221 or 8488 did not exhibit clinical signs of ETEC disease; most piglets inoculated with 8017 showed diarrhea. Control pigs exhibited significant weight loss, increased blood total protein, and higher numbers of colony-forming units of 3030-2 E. coli in washed ileum and jejunum than treated pigs. This study shows for the first time that pre-inoculation with an avirulent strain expressing adhesive fimbriae and a non-toxic form of LT provides significant short term protection from challenge with a virulent ETEC strain that expresses the same fimbrial adhesion and enterotoxin.

  16. Genetic Characterization and Immunogenicity of Coli Surface Antigen 4 from Enterotoxigenic Escherichia coli when It Is Expressed in a Shigella Live-Vector Strain

    PubMed Central

    Altboum, Zeev; Levine, Myron M.; Galen, James E.; Barry, Eileen M.

    2003-01-01

    The genes that encode the enterotoxigenic Escherichia coli (ETEC) CS4 fimbriae, csaA, -B, -C, -E, and -D′, were isolated from strain E11881A. The csa operon encodes a 17-kDa major fimbrial subunit (CsaB), a 40-kDa tip-associated protein (CsaE), a 27-kDa chaperone-like protein (CsaA), a 97-kDa usher-like protein (CsaC), and a deleted regulatory protein (CsaD′). The predicted amino acid sequences of the CS4 proteins are highly homologous to structural and assembly proteins of other ETEC fimbriae, including CS1 and CS2, and to CFA/I in particular. The csaA, -B, -C, -E operon was cloned on a stabilized plasmid downstream from an osomotically regulated ompC promoter. pGA2-CS4 directs production of CS4 fimbriae in both E. coli DH5α and Shigella flexneri 2a vaccine strain CVD 1204, as detected by Western blot analysis and bacterial agglutination with anti-CS4 immune sera. Electron-microscopic examination of Shigella expressing CS4 confirmed the presence of fimbriae on the bacterial surface. Guinea pigs immunized with CVD 1204(pGA2-CS4) showed serum and mucosal antibody responses to both the Shigella vector and the ETEC fimbria CS4. Among the seven most prevalent fimbrial antigens of human ETEC, CS4 is the last to be cloned and sequenced. These findings pave the way for CS4 to be included in multivalent ETEC vaccines, including an attenuated Shigella live-vector-based ETEC vaccine. PMID:12595452

  17. [Genotypic characterization of toxigenic Escherichia coli isolated from pigs with postweaning diarrhea (PWD) and edema disease (ED)].

    PubMed

    Moredo, Fabiana A; Cappuccio, Javier A; Insarralde, Lucas; Perfumo, Carlos J; Quiroga, María A; Leotta, Gerardo A

    2012-01-01

    The purpose of this work was to characterize 47 Escherichia coli strains isolated from 32 pigs diagnosed with postweaning diarrhea and three pigs with edema disease by PCR. Forty two (95.5 %) of the strains isolated from diarrheic pigs were characterized as enterotoxigenic E. coli (ETEC) and 2 (4.5 %) as Shiga toxin-producing E. coli (STEC). Fourteen (33.3 %) ETEC strains were positive for est/estII/fedA genes. The most complex genotype was eltA/estI/faeG/aidA. Strains isolated from pigs with ED were classified as porcine STEC and were stx2e/aidA carriers. Eleven (25 %) strains carried the gene encoding adhesin protein AIDA-I. However, genes coding for F5, F6, F41, intimin and Paa were not detected. The development of vaccines generating antibodies against prevalent E. coli adhesins in Argentina could be useful for the prevention of PWD and ED.

  18. Analysis of the unique structural and physicochemical properties of the DraD/AfaD invasin in the context of its belonging to the family of chaperone/usher type fimbrial subunits

    PubMed Central

    2011-01-01

    Background DraD invasin encoded by the dra operon possesses a classical structure characteristic to fimbrial subunits of the chaperone/usher type. The Ig-fold of the DraD possesses two major characteristics distinguishing it from the family of fimbrial subunits: 1) a distortion of the β-barrel structure in the region of the acceptor cleft, demonstrated by a disturbance of the main-chain hydrogen bonds network, and 2) an unusually located disulfide bond connecting B and F strands - the localization exclusively observed in the subfamily of DraD/AfaD-type subunits. Results To evaluate the influence of the DraD-sc specific structural features on its stability and mechanism of thermal denaturation, a series of DSC and FT-IR denaturation experiments were performed giving following conclusions. 1) The DraD-sc is characterized by a low stability (standard Gibbs free energy and enthalpy of unfolding of 18.4 ±1.4 kJ mol-1 and 131 ±25 kJ mol-1, respectively) that contrasts strongly with almost infinite stability of the described previously DraE-sc fimbrial protein. 2) The DraD-sc unfolds thermally according to the two state equilibrium model, in contrast to the irreversible kinetically controlled transition of the DraE-sc. 3) The DraD specific disulfide bond is crucial at the folding stage and has little stability effect in the mature protein. Conclusions Data published so far emphasize unique biological properties of the DraD invasin as fimbrial subunit: a chaperone independent folding, an usher independent surface localization and the possibility to exist in two forms: as unbound subunits and as loosely bound at fimbrial tip. Presented calorimetric and FT-IR stability data combined with structural correlations has underlined that the DraD invasin is also characterized by unique physicochemical and structural attributes in the context of its belonging to the family of fimbrial subunits. PMID:21575181

  19. The majority of enteroaggregative Escherichia coli strains produce the E. coli common pilus when adhering to cultured epithelial cells.

    PubMed

    Avelino, Fabiola; Saldaña, Zeus; Islam, Sohidul; Monteiro-Neto, Valerio; Dall'Agnol, Monique; Eslava, Carlos A; Girón, Jorge A

    2010-11-01

    Enteroaggregative Escherichia coli (EAEC) have emerged as a significant worldwide cause of chronic diarrhea in the pediatric population and in HIV patients. The vast majority of EAEC strains do not produce the aggregative adherence fimbriae I-III (AAFs) so far reported and thus, what adherence factors are present in these strains remains unknown. Here, we investigated the prevalence of the chromosomal E. coli common pilus (ECP) genes and ECP production amongst 130 EAEC strains of diverse origin as well as the role of ECP in EAEC adherence. Through multiplex PCR analysis we found that 96% of EAEC strains contained the ecpA structural pilin gene whereas only 3.1% and 5.4% were positive for AAF fimbrial genes aggA or aafA, respectively. Among the ecpA(+) strains, 63% produced ECP when adhering to cultured epithelial cells. An ecpA mutant derived from prototypic strain 042 (AAF/II(+)) was not altered in adherence suggesting that the AAF/II, and not ECP, plays a major role in this strain. In contrast, strain 278-1 (AAF(-)) deleted of the ecpA gene was significantly reduced in adherence to cultured epithelial cells. In all, these data indicate a potential role of ECP in adherence for EAEC strains lacking the known AAFs and that in association with other adhesive determinants, ECP may contribute to their survival and persistence within the host and in the environment.

  20. Afa/Dr diffusely adhering Escherichia coli C1845 infection promotes selective injuries in the junctional domain of polarized human intestinal Caco-2/TC7 cells.

    PubMed

    Peiffer, I; Blanc-Potard, A B; Bernet-Camard, M F; Guignot, J; Barbat, A; Servin, A L

    2000-06-01

    The Afa/Dr diffusely adhering Escherichia coli (DAEC) C1845 strain harboring the F1845 fimbrial adhesin interacts with the brush border-associated CD55 molecule and promotes elongation of brush border microvilli resulting from rearrangement of the F-actin network. This phenomenon involves the activation of a cascade of signaling coupled to the glycosylphosphatidylinositol-anchored receptor of the F1845 adhesin. We provide evidence that infection of the polarized human intestinal cell line Caco-2/TC7 by strain C1845 is followed by an increase in the paracellular permeability for [(3)H]mannitol without a decrease of the transepithelial resistance of the monolayers. Alterations in the distribution of tight-junction (TJ)-associated occludin and ZO-1 protein are observed, whereas the distribution of the zonula adherens-associated E-cadherin is not affected. Using the recombinant E. coli strains HB101(pSSS1) and -(pSSS1C) expressing the F1845 fimbrial adhesin, we demonstrate that the adhesin-CD55 interaction is not sufficient for the induction of structural and functional TJ lesions. Moreover, using the actin filament-stabilizing agent Jasplakinolide, we demonstrate that the C1845-induced functional alterations in TJs are independent of the C1845-induced apical cytoskeleton rearrangements. The results indicated that pathogenic factor(s) other than F1845 adhesin may be operant in Afa/Dr DAEC C1845.

  1. Crystallization and preliminary X-ray diffraction analysis of CfaE, the adhesive subunit of the CFA/I fimbriae from human enterotoxigenic Escherichia coli

    SciTech Connect

    Li, Yong-Fu; Poole, Steven; Rasulova, Fatima; Esser, Lothar; Savarino, Stephen J.; Xia, Di

    2006-02-01

    The adhesin CfaE of the CFA/I fimbriae from human enterotoxigenic E. coli has been crystallized. CfaE crystals diffracted X-rays to better than 2.4 Å and phasing was solved by the SIRAS method. Enterotoxigenic Escherichia coli (ETEC) represents a formidable food and waterborne diarrheal disease threat of global importance. The first step in ETEC pathogenesis is bacterial attachment to small-intestine epithelial cells via adhesive fimbriae, many of which are genetically related to the prototype colonization factor antigen I (CFA/I). The minor fimbrial subunit CfaE is required for initiation of CFA/I fimbrial assembly and mediates bacterial attachment to host cell-surface receptors. A donor-strand complemented variant of CfaE (dscCfaE) was expressed with a hexahistidine tag, purified to homogeneity and crystallized using the hanging-drop vapor-diffusion method. X-ray diffraction data sets were collected to 2.4 Å resolution for both native and derivatized crystals and showed the symmetry of space group P6{sub 2}22, with unit-cell parameters a = b = 142.9, c = 231.9 Å. Initial phases were derived from the SIRAS approach and electron density showed two molecules in the crystallographic asymmetric unit. Sequence assignments were aided by anomalous signals from the selenium of an SeMet-derivatized crystal and from S atoms of a native crystal.

  2. Development and Efficacy Assessment of an Enteric Coated Porous Tablet Loaded With F4 Fimbriae for Oral Vaccination of Piglets against F4+ Escherichia coli Infections.

    PubMed

    Srivastava, Atul; Gowda, D V; Madhunapantula, SubbaRao V; Siddaramaiah

    2016-01-01

    Enterotoxigenic Escherichia coli (ETEC) infection is one of the major causes contributing to the development of diarrhoea and mortality in new born, suckling and newly weaned piglets. To date, no preventive/treatment strategy showed promising results, which could be due to the lack of potent vaccines, and/or due to the development of resistance of ETEC to antibiotics. Therefore, in the present investigation, a novel porous sodium alginate (SA) tablet formulation loaded with F4 fimbriae antigen was developed and tested for efficacy against ETEC infections in piglet models. Precompression parameters of the powder mixes and post compression parameters of tablets have been evaluated and results were found to be satisfactory. Loading of F4 fimbrial antigens into the tablets was achieved by inducing pores in the tablets via the sublimation of camphor followed by incubation with purified F4 fimbriae. The loaded tablets have been coated with Eudragit L100 to protect the F4 fimbriae from (a) highly acidic gastric environment; (b) proteolytic cleavage by pepsin; and (c) to promote subsequent release in the intestine. Evaluation of developed F4 fimbrial tablets in a Pig model demonstrated induction of mucosal immunity, and a significant reduction of F4+ E. coli in faeces. Therefore, F4 fimbriae loaded porous tablets could be a novel oral vaccination candidate to induce mucosal and systemic immunity against ETEC infections.

  3. Genome Sequences and Phylogenetic Analysis of K88- and F18-Positive Porcine Enterotoxigenic Escherichia coli

    PubMed Central

    Shepard, Sara M.; Danzeisen, Jessica L.; Isaacson, Richard E.; Seemann, Torsten; Achtman, Mark

    2012-01-01

    Porcine enterotoxigenic Escherichia coli (ETEC) continues to result in major morbidity and mortality in the swine industry via postweaning diarrhea. The key virulence factors of ETEC strains, their serotypes, and their fimbrial components have been well studied. However, most studies to date have focused on plasmid-encoded traits related to colonization and toxin production, and the chromosomal backgrounds of these strains have been largely understudied. Here, we generated the genomic sequences of K88-positive and F18-positive porcine ETEC strains and examined the phylogenetic distribution of clinical porcine ETEC strains and their plasmid-associated genetic content. The genomes of porcine ETEC strains UMNK88 and UMNF18 were both found to contain remarkable plasmid complements containing known virulence factors, potential novel virulence factors, and antimicrobial resistance-associated elements. The chromosomes of these strains also possessed several unique genomic islands containing hypothetical genes with similarity to classical virulence factors, although phage-associated genomic islands dominated the accessory genomes of these strains. Phylogenetic analysis of 78 clinical isolates associated with neonatal and porcine diarrhea revealed that a limited subset of porcine ETEC lineages exist that generally contain common toxin and fimbrial profiles, with many of the isolates belonging to the ST10, ST23, and ST169 multilocus sequencing types. These lineages were generally distinct from existing human ETEC database isolates. Overall, most porcine ETEC strains appear to have emerged from a limited subset of E. coli lineages that either have an increased propensity to carry plasmid-encoded virulence factors or have the appropriate ETEC core genome required for virulence. PMID:22081385

  4. E. Coli and Pregnancy

    MedlinePlus

    ... care provider. What is E. coli? E. coli (Escherichia coli) is a bacterium that lives in your colon ( ... 10):1411-1413. Jones B, et al. 2004. Escherichia coli: a growing problem in early onset neonatal sepsis. ...

  5. Clonal and pathotypic analysis of archetypal Escherichia coli cystitis isolate NU14.

    PubMed

    Johnson, J R; Weissman, S J; Stell, A L; Trintchina, E; Dykhuizen, D E; Sokurenko, E V

    2001-12-15

    Escherichia coli NU14, a cystitis isolate used to study the pathogenesis of cystitis and to develop a FimH (type 1 fimbrial adhesin) vaccine, was assessed for extended virulence genotype, phylogenetic background, and FimH sequence and binding phenotype(s). NU14 exhibited the same virulence genotype and was derived from the same (meningitis- and cystitis-associated) subclone of E. coli O18:K1:H7 as the archetypal neonatal bacterial meningitis (NBM) isolate RS218. NU14 also displayed the same Ser62Ala FimH polymorphism as did NBM isolates RS218 and IHE3034-conferring both collagen binding and a distinct monomannose binding capability (which characterizes uropathogenic but not commensal E. coli and dramatically increases adherence to uroepithelial cells). These findings establish that strain NU14 exhibits numerous urovirulence-associated traits and derives from the single most prevalent clonal group in acute cystitis. They provide further evidence of clonal and pathotypic similarities between cystitis and NBM isolates of E. coli O18:K1:H7.

  6. Escherichia Coli

    ERIC Educational Resources Information Center

    Goodsell, David S.

    2009-01-01

    Diverse biological data may be used to create illustrations of molecules in their cellular context. I describe the scientific results that support a recent textbook illustration of an "Escherichia coli cell". The image magnifies a portion of the bacterium at one million times, showing the location and form of individual macromolecules. Results…

  7. A high-molecular-weight outer membrane protein of Xanthomonas oryzae pv. oryzae exhibits similarity to non-fimbrial adhesins of animal pathogenic bacteria and is required for optimum virulence.

    PubMed

    Ray, Suvendra K; Rajeshwari, R; Sharma, Yogendra; Sonti, Ramesh V

    2002-11-01

    Transposon insertions in a novel 3.798 kb open reading frame (ORF) of the rice pathogen, Xanthomonas oryzae pv. oryzae (Xoo) cause virulence deficiency and altered colony/lawn morphology. This ORF encodes a protein, XadA, of 1,265 amino acids that exhibits significant similarity to non-fimbrial adhesins of animal pathogenic bacteria such as Yersinia YadA and Moraxella UspA1. An interesting feature is that the YadA similarity region is repeated six times within the XadA sequence and encompasses almost the entire length of the protein. Anti-XadA antibodies identified a 110 kDa outer membrane protein that was sensitive to protease treatment of whole cells. XadA expression is induced in minimal medium. Homology modelling suggests that XadA adopts a beta-helix conformation-like pertactin, a non-fimbrial adhesin of Bordetella pertussis. This work is the first characterization of a non-fimbrial adhesin-like molecule in a plant pathogenic bacterium. It extends our knowledge about the repertoire of homologous virulence factors that are deployed by animal and plant pathogenic bacteria to include functions potentially involved in adhesion.

  8. The distribution of Escherichia coli serovars, virulence genes, gene association and combinations and virulence genes encoding serotypes in pathogenic E. coli recovered from diarrhoeic calves, sheep and goat.

    PubMed

    Osman, K M; Mustafa, A M; Elhariri, M; Abdelhamed, G S

    2013-02-01

    Ruminants, especially cattle, have been implicated as a principal reservoir of one of the enterovirulent Escherichia coli pathotypes. The detection of the virulence genes in diarrhoeic calves and small ruminants has not been studied in Egypt. To determine the occurrence, serotypes and the virulence gene markers, stx1, stx2, hylA, Flic(h7) , stb, F41, K99, sta, F17, LT-I, LT-II and eae, rectal swabs were taken from diarrhoeic calves, sheep and goats and subjected to bacterial culture and PCR. The E. coli prevalence rate in the diarrhoeic animals was 63.6% in calves, 27.3% in goat and 9.1% in sheep. The 102 E. coli strains isolated from the calves, goat and sheep were 100% haemolytic non-verotoxic and fitted into the Eagg group. The isolates belonged to seven O serogroups (O25, O78, O86, O119, O158, O164 and O157). The eae gene was detected in six of the strains isolated from the calves. The 102 bovine, ovine and caprine E. coli strains isolated in this study were negative for stx1, stx2, F41, LT-I and Flic(h7) genes. The highest gene combinations were found to occur in the form of 24/102 isolates (23.5%) that carried the F17 gene predominantly associated with eaeA, hylA, K99 and Stb genes in the calves, while the hylA, K99 and Sta were the only genes found to be in conjunction in both calves and goats (6/102; 5.9% each). Our data show that in Egypt, large and small ruminants could be a potential source of infection in humans.

  9. Piracy of decay-accelerating factor (CD55) signal transduction by the diffusely adhering strain Escherichia coli C1845 promotes cytoskeletal F-actin rearrangements in cultured human intestinal INT407 cells.

    PubMed

    Peiffer, I; Servin, A L; Bernet-Camard, M F

    1998-09-01

    Diffusely adhering Escherichia coli (DAEC) C1845 (clinical isolate) harboring the fimbrial adhesin F1845 can infect cultured human differentiated intestinal epithelial cells; this process is followed by the disassembly of the actin network in the apical domain. The aim of this study was to examine the mechanism by which DAEC C1845 promotes F-actin rearrangements. For this purpose, we used a human embryonic intestinal cell line (INT407) expressing the membrane-associated glycosylphosphatidylinositol (GPI) protein-anchored decay-accelerating factor (DAF), the receptor of the F1845 adhesin. We show here that infection of INT407 cells by DAEC C1845 can provoke dramatic F-actin rearrangements without cell entry. Clustering of phosphotyrosines was observed, revealing that the DAEC C1845-DAF interaction involves the recruitment of signal transduction molecules. A pharmacological approach with a subset of inhibitors of signal transduction molecules was used to identify the cascade of signal transduction molecules that are coupled to the DAF, that are activated upon infection, and that promote the F-actin rearrangements. DAEC C1845-induced F-actin rearrangements can be blocked dose dependently by protein tyrosine kinase, phospholipase Cgamma, phosphatidylinositol 3-kinase, protein kinase C, and Ca2+ inhibitors. F-actin rearrangements and blocking by inhibitors were observed after infection of the cells with two E. coli recombinants carrying the plasmids containing the fimbrial adhesin F1845 or the fimbrial hemagglutinin Dr, belonging to the same family of adhesins. These findings show that the DAEC Dr family of pathogens promotes alterations in the intestinal cell cytoskeleton by piracy of the DAF-GPI signal cascade without bacterial cell entry.

  10. Detection of enterotoxigenic Escherichia coli colonization factor antigen I in stool specimens by an enzyme-linked immunosorbent assay.

    PubMed Central

    Evans, D G; Evans, D J; Clegg, S

    1980-01-01

    An enzyme-linked immunosorbent assay (ELISA) was employed to detect and quantitate the fimbrial colonization factor antigen (CFA/I) of enterotoxigenic Escherichia coli in stool specimens obtained from adult cases of diarrhea in which CFA/I-positive E. coli was the known causative agent. The inhibition method, or blocking technique, was used. In this method, a standardized dilution of human anti-CFA/I serum was preincubated with dilutions of stool extract before transfer to CFA/I-coated microtiter plate wells, and then ELISA was performed with alkaline phosphatase-conjugated anti-human immunoglobulin. CFA/I purified from E. coli strain H-10407 (O78:H11) was used. Acute-phase diarrheal stool specimens were found to contain approximately 3.0 mg of antigen (mean value) per g stool, whereas control (CFA/I-negative) specimens contained insignificant amounts (less than 0.03 mg/g) of antigen. Also, CFA/I was detected in culture fluids of CFA/I positive enterotoxigenic E. coli belonging to a variety of serotypes and was undetectable in similar preparations from P-strains (spontaneous CFA/I-negative derivatives) of the same test cultures. Equivalent results were obtained in ELISA tests by using bacterial cells taken from isolated colonies grown on CFA agar. These results indicate that the ELISA technique will be useful for the diagnosis of diarrhea caused by CFA/I-positive enterotoxigenic E. coli. PMID:7031075

  11. The role of Type 1, P and S fimbriae in binding of Escherichia coli to the canine endometrium.

    PubMed

    Krekeler, N; Marenda, M S; Browning, G F; Holden, K M; Charles, J A; Wright, P J

    2013-06-28

    Escherichia coli (E. coli) is the most commonly isolated infectious agent causing pyometra in bitches. Many E. coli strains isolated from the uteri of infected dogs carry several adhesin genes (fimH, papGIII and sfa). The objective of this study was to investigate the role of each adhesin gene product, acting alone or expressed in combination, in the bacterial binding to canine endometrium. E. coli strain P3, which was isolated from a uterus of a bitch naturally affected with pyometra, was shown by PCR to carry all three known fimbrial adhesin genes fimH, papGIII and sfa. Knockout (KO) mutants of this wildtype (P3-wt) strain were generated using insertional inactivation. Adhesion assays on anoestrous uteri of three post-pubertal bitches were undertaken. Overall, the number of bacteria adhering to canine endometrial biopsies was comparable between strains and no significant difference in the number of bound bacteria was found between the P3-wt strain and the single or double KO-strains. However, the triple knockout strain displayed less binding to the canine endometrium compared with the P3-wt strain. This study shows that a pathogenic E. coli strain (P3) isolated from the uterus of a bitch with pyometra was able to fully compensate for the loss of two of its three known adhesin genes. It was necessary to inactivate all three known adhesin genes in order to see a significant decrease in binding to canine endometrium.

  12. Two autonomous structural modules in the fimbrial shaft adhesin FimA mediate Actinomyces interactions with streptococci and host cells during oral biofilm development

    SciTech Connect

    Mishra, Arunima; Devarajan, Bharanidharan; Reardon, Melissa E.; Dwivedi, Prabhat; Krishnan, Vengadesan; Cisar, John O.; Das, Asis; Narayana, Sthanam V.L.; Ton-That, Hung

    2011-09-06

    By combining X-ray crystallography and modelling, we describe here the atomic structure of distinct adhesive moieties of FimA, the shaft fimbrillin of Actinomyces type 2 fimbriae, which uniquely mediates the receptor-dependent intercellular interactions between Actinomyces and oral streptococci as well as host cells during the development of oral biofilms. The FimA adhesin is built with three IgG-like domains, each of which harbours an intramolecular isopeptide bond, previously described in several Gram-positive pilins. Genetic and biochemical studies demonstrate that although these isopeptide bonds are dispensable for fimbrial assembly, cell-cell interactions and biofilm formation, they contribute significantly to the proteolytic stability of FimA. Remarkably, FimA harbours two autonomous adhesive modules, which structurally resemble the Staphylococcus aureus Cna B domain. Each isolated module can bind the plasma glycoprotein asialofetuin as well as the polysaccharide receptors present on the surface of oral streptococci and epithelial cells. Thus, FimA should serve as an excellent paradigm for the development of therapeutic strategies and elucidating the precise molecular mechanisms underlying the interactions between cellular receptors and Gram-positive fimbriae.

  13. The Protein Interaction Network of Bacteriophage Lambda with Its Host, Escherichia coli

    PubMed Central

    Blasche, Sonja; Wuchty, Stefan; Rajagopala, Seesandra V.

    2013-01-01

    Although most of the 73 open reading frames (ORFs) in bacteriophage λ have been investigated intensively, the function of many genes in host-phage interactions remains poorly understood. Using yeast two-hybrid screens of all lambda ORFs for interactions with its host Escherichia coli, we determined a raw data set of 631 host-phage interactions resulting in a set of 62 high-confidence interactions after multiple rounds of retesting. These links suggest novel regulatory interactions between the E. coli transcriptional network and lambda proteins. Targeted host proteins and genes required for lambda infection are enriched among highly connected proteins, suggesting that bacteriophages resemble interaction patterns of human viruses. Lambda tail proteins interact with both bacterial fimbrial proteins and E. coli proteins homologous to other phage proteins. Lambda appears to dramatically differ from other phages, such as T7, because of its unusually large number of modified and processed proteins, which reduces the number of host-virus interactions detectable by yeast two-hybrid screens. PMID:24049175

  14. The afimbrial adhesive sheath encoded by the afa-3 gene cluster of pathogenic Escherichia coli is composed of two adhesins.

    PubMed

    Garcia, M I; Gounon, P; Courcoux, P; Labigne, A; Le Bouguenec, C

    1996-02-01

    The afa-3 gene cluster determines the formation of an afimbrial adhesive sheath that is expressed by uropathogenic as well as diarrhoea-associated Escherichia coli strains. It contains six genes (afaA-afaF), among which the afaE3 gene is known to code for the structural AfaE-III adhesin (previously designated AFA-III), whereas no role has yet been identified for the afaD gene product. The afa-3 gene cluster is closely related to the daa operon that codes for an adhesin, the F1845 adhesin, which is highly related to the AfaE-III adhesin; however, unlike the AfaE-III adhesin, F1845 is a fimbrial adhesin. Reported in this work is the construction of chimeras between the afa-3 and daa operons. Analyses of the phenotypes conferred by these afa-3/daa chimeric clusters allowed us to conclude that the biogenesis of a fimbrial or an afimbrial adhesin is fully determined by the amino acid sequence of the AfaE-III and F1845 adhesins. Moreover, the role of the AfaD product in the biosynthesis of the afimbrial sheath was assessed by immunogold and immunofluorescence experiments. The AfaD and the AfaE-III products were purified and used to raise rabbit and mouse antisera. Similar to AfaE-III, AfaD was found to be a surface-exposed protein as well as an adhesin; both AfaD and AfaE-III are concomittantly expressed by the bacterial cell. These results demonstrate, for the first time, that the afimbrial adhesive sheath expressed by pathogenic E. coli is composed of two adhesins.

  15. Adhesion of human enterotoxigenic Escherichia coli to human mucus secreting HT-29 cell subpopulations in culture.

    PubMed Central

    Kerneis, S; Bernet, M F; Coconnier, M H; Servin, A L

    1994-01-01

    Enterotoxigenic Escherichia coli (ETEC) bearing the fimbrial colonisation factor antigens CFA/I, CFA/II, CFA/III, and the non-fimbrial antigen 2230 were tested for their ability to adhere to two cultured human intestinal HT-29 mucus secreting cell subpopulations. These populations are referred to as HT29-MTX and HT29-FU, which differ in the amount of secreted mucins and in their gastric or colonic mucin immunoreactivity respectively. Adherence of radiolabelled bacteria to cell monolayers infected apically was assessed. All ETEC strains adhered to the mucus secreting HT29-FU subpopulation, which secretes mucins of colonic immunoreactivity. Visualisation of bacteria by scanning electron microscopy showed that ETEC bound to the HT29-FU cells possessing a brush border, but not to the mucus and that ETEC binding developed as a function of cell differentiation. The adhesion of ETEC to cells possessing a brush border and to mucus secreting cells was also analysed by indirect immunofluorescence in HT29-MTX cells, which secrete mucins of gastric immunoreactivity. Fluorescein isothiocyanate labelling using specific anti-CFA/I antibody was used to show ETEC; rhodamine isothiocyanate labelling using a monoclonal antibody (designated M1) against purified human gastric mucus was used to detect secreted mucins, and rhodamine isothiocyanate labelling using a monoclonal antibody (designated 4H3) against human dipeptidylpeptidase IV was used to show cells possessing a brush border. Binding of bacteria colocalised with dipeptidylpeptidase IV of enterocytes and not with mucins. Images Figure 1 Figure 2 Figure 3 Figure 5 PMID:7959203

  16. Immunogenicity of a prototype enterotoxigenic Escherichia coli adhesin vaccine in mice and nonhuman primates.

    PubMed

    Sincock, Stephanie A; Hall, Eric R; Woods, Colleen M; O'Dowd, Aisling; Poole, Steven T; McVeigh, Annette L; Nunez, Gladys; Espinoza, Nereyda; Miller, Milagros; Savarino, Stephen J

    2016-01-04

    Enterotoxigenic Escherichia coli (ETEC) are the most common cause of bacterial diarrhea in young children in developing countries and in travelers. Efforts to develop an ETEC vaccine have intensified in the past decade, and intestinal colonization factors (CFs) are somatic components of most investigational vaccines. CFA/I and related Class 5 fimbrial CFs feature a major stalk-forming subunit and a minor, antigenically conserved tip adhesin. We hypothesized that the tip adhesin is critical for stimulating antibodies that specifically inhibit ETEC attachment to the small intestine. To address this, we compared the capacity of donor strand complemented CfaE (dscCfaE), a stabilized form of the CFA/I fimbrial tip adhesin, and CFA/I fimbriae to elicit anti-adhesive antibodies in mice, using hemagglutination inhibition (HAI) as proxy for neutralization of intestinal adhesion. When given with genetically attenuated heat-labile enterotoxin LTR192G as adjuvant by intranasal (IN) or orogastric (OG) vaccination, dscCfaE exceeded CFA/I fimbriae in eliciting serum HAI titers and anti-CfaE antibody titers. Based on these findings, we vaccinated Aotus nancymaae nonhuman primates (NHP) with dscCfaE alone or admixed with one of two adjuvants, LTR192G and cholera toxin B-subunit, by IN and OG administration. Only IN vaccination with dscCfaE with either adjuvant elicited substantial serum HAI titers and IgA and IgG anti-adhesin responses, with the latter detectable a year after vaccination. In conclusion, we have shown that dscCfaE elicits robust HAI and anti-adhesin antibody responses in both mice and NHPs when given with adjuvant by IN vaccination, encouraging further evaluation of an ETEC adhesin-based vaccine approach.

  17. Pathogenicity of an Escherichia coli O115:K"V165" mutant negative for F165(1) fimbriae in septicemia of gnotobiotic pigs.

    PubMed Central

    Ngeleka, M; Jacques, M; Martineau-Doizé, B; Daigle, F; Harel, J; Fairbrother, J M

    1993-01-01

    To evaluate the role of the F165(1) fimbrial system in the pathogenesis of septicemia, 2-day-old germfree pigs were inoculated intragastrically with Escherichia coli O115:K"V165":F165 wild-type strain 5131, its F165(1)-negative TnphoA mutant M48, or E. coli O115:K(-):F165(-) wild-type strain 862B. Pigs were sacrificed at different times (3, 6, 12, 24, 48, and 96 h) postinfection (p.i.). Pigs inoculated with strain 5131 developed clinical signs (anorexia, lameness, reluctance to move, or lack of motor coordination) and were moribund within 48 h p.i., and, at necropsy, infecting bacteria were isolated in various extraintestinal organs. Strain 5131 was isolated as early as 6 h p.i. from the blood of inoculated pigs. Pigs inoculated with mutant M48 developed only mild clinical signs at 96 h p.i. Mutant M48 colonized extraintestinal organs of pigs but to a lesser extent than the parent strain did. In contrast to the parent strain, this mutant was not isolated in the blood of inoculated pigs. Pigs inoculated with strain 862B remained normal during the experiment. All of the strains colonized the mucus layer of the intestine, but no histological changes of intestinal mucosa were observed by either light or electron microscopy. The parent strain, but not the mutant M48, expressed F165(1) in vivo. In a competitive study in which the parent strain and its afimbrial mutant were inoculated simultaneously, clinical signs of septicemia developed 24 h after inoculation, and only the parent strain 5131 was isolated from the blood of inoculated pigs. Our results suggest that the F165(1) fimbrial system of E. coli O115:K"V165" strains may play an important role in the ability of the bacteria to survive in the blood and spread systemically through the porcine host. Images PMID:8094383

  18. Sequence analysis of the clpG gene, which codes for surface antigen CS31A subunit: evidence of an evolutionary relationship between CS31A, K88, and F41 subunit genes.

    PubMed Central

    Girardeau, J P; Bertin, Y; Martin, C; Der Vartanian, M; Boeuf, C

    1991-01-01

    The clpG gene coding for the CS31A subunit was localized on a 0.9-kb SphI fragment from the recombinant plasmid pAG315. This was established by testing the ability of subclones to hybridize with a 17-meric oligonucleotide probe obtained from N-terminal analysis of the CS31A subunit. The nucleotide sequence of the region coding for CS31A was determined. From primer extension analysis, two initiation translation start sites were detected. Two possible promoterlike sequences were identified; the ribosome binding site and the translation terminator are proposed. Inverted repeat sequences leading to the formation of possible hairpin structures of the transcripts were found on the 5' untranslated region of clpG. The deduced amino acid composition was in close agreement with the chemical amino acid composition and sequence match with the first 25 N-terminal amino acids from the published N-terminal sequence of the purified CS31A subunit. The clpG gene codes for a mature protein of 257 amino acids with a molecular size of 26,777 Da. An obvious homology was observed when the amino acid sequence of CS31A was compared with those of K88 and F41. This homology includes five different conserved sequences of up to 19 identical amino acids, which is associated with conserved proline. An extensive change in the CS31A region homologous to that identified to contain the K88 receptor binding site might be responsible for the functional divergence between CS31A and K88. Images FIG. 4 FIG. 5 PMID:1938963

  19. In Vitro Activities of Cephalosporins and Quinolones against Escherichia coli Strains Isolated from Diarrheic Dairy Calves

    PubMed Central

    Orden, José Antonio; Ruiz-Santa-Quiteria, José Antonio; García, Silvia; Cid, Dolores; de la Fuente, Ricardo

    1999-01-01

    The in vitro activities of several cephalosporins and quinolones against 195 strains of Escherichia coli isolated from dairy calves affected by neonatal diarrhea were determined. One hundred thirty-seven of these strains produced one or more potential virulence factors (F5, F41, F17, cytotoxic necrotizing factor, verotoxin, and the eae gene), but the remaining 58 strains did not produce any of these factors. From 11 to 18% of the E. coli strains were resistant to cephalothin, nalidixic acid, enoxacin, and enrofloxacin. However, cefuroxime, cefotaxime, and cefquinome were highly effective against the E. coli isolates tested. Some significant differences (P < 0.05) in resistance to quinolones between the strains producing potential virulence factors and nonfimbriated, nontoxigenic, eae-negative strains were found. Thus, eae-positive, necrotoxigenic, and verotoxigenic (except for nalidixic acid) E. coli strains were significantly more sensitive to nalidixic acid, enoxacin, and enrofloxacin than nonfimbriated, nontoxigenic, eae-negative strains. Moreover, eae-positive strains were significantly more sensitive to enoxacin and enrofloxacin than F5-positive strains. Thus, the results of this study suggest that the bovine E. coli strains that produce some potential virulence factors are more sensitive to quinolones than those that do not express these factors. PMID:10049259

  20. Diarrheagenic Escherichia coli

    PubMed Central

    Nataro, James P.; Kaper, James B.

    1998-01-01

    Escherichia coli is the predominant nonpathogenic facultative flora of the human intestine. Some E. coli strains, however, have developed the ability to cause disease of the gastrointestinal, urinary, or central nervous system in even the most robust human hosts. Diarrheagenic strains of E. coli can be divided into at least six different categories with corresponding distinct pathogenic schemes. Taken together, these organisms probably represent the most common cause of pediatric diarrhea worldwide. Several distinct clinical syndromes accompany infection with diarrheagenic E. coli categories, including traveler’s diarrhea (enterotoxigenic E. coli), hemorrhagic colitis and hemolytic-uremic syndrome (enterohemorrhagic E. coli), persistent diarrhea (enteroaggregative E. coli), and watery diarrhea of infants (enteropathogenic E. coli). This review discusses the current level of understanding of the pathogenesis of the diarrheagenic E. coli strains and describes how their pathogenic schemes underlie the clinical manifestations, diagnostic approach, and epidemiologic investigation of these important pathogens. PMID:9457432

  1. Function and Expression of an N-Acetylneuraminic Acid-Inducible Outer Membrane Channel in Escherichia coli

    PubMed Central

    Condemine, Guy; Berrier, Catherine; Plumbridge, Jacqueline; Ghazi, Alexandre

    2005-01-01

    The Escherichia coli yjhA (renamed nanC) gene encodes a protein of the KdgM family of outer membrane-specific channels. It is transcribed divergently from fimB, a gene involved in the site-specific inversion of the region controlling transcription of the fimbrial structural genes but is separated from it by one of the largest intergenic regions in E. coli. We show that nanC expression is induced by N-acetylneuraminic acid and modulated by N-acetylglucosamine. This regulation occurs via the NanR and NagC regulators, which also control fimB expression. nanC expression is also activated by the regulators cyclic AMP-catabolite activator protein, OmpR, and CpxR. When the NanC protein was reconstituted into liposomes, it formed channels with a conductance of 450 pS at positive potential and 300 to 400 pS at negative potential in 800 mM KCl. The channels had a weak anionic selectivity. In an ompR background, where the general porins OmpF and OmpC are absent, NanC is required for growth of E. coli on N-acetylneuraminic acid as the sole carbon source. All these results suggest that NanC is an N-acetylneuraminic acid outer membrane channel protein. PMID:15743943

  2. Examination of the genome-wide transcriptional response of Escherichia coli O157:H7 to cinnamaldehyde exposure.

    PubMed

    Visvalingam, Jeyachchandran; Hernandez-Doria, Juan David; Holley, Richard A

    2013-02-01

    Cinnamaldehyde is a natural antimicrobial that has been found to be effective against many food-borne pathogens, including Escherichia coli O157:H7. Although its antimicrobial effects have been well investigated, limited information is available on its effects at the molecular level. Sublethal treatment at 200 mg/liter cinnamaldehyde inhibited growth of E. coli O157:H7 at 37°C and for ≤2 h caused cell elongation, but from 2 to 4 h growth resumed and cells reverted to normal length. To understand this transient behavior, genome-wide transcriptional analysis of E. coli O157:H7 was performed at 2 and 4 h of exposure to cinnamaldehyde in conjunction with reverse-phase high-performance liquid chromatography (RP-HPLC) analysis for cinnamaldehyde and other cinnamic compounds. Drastically different gene expression profiles were obtained at 2 and 4 h. RP-HPLC analysis showed that cinnamaldehyde was structurally stable for at least 2 h. At 2 h of exposure, cinnamaldehyde induced expression of many oxidative stress-related genes and repressed expression of DNA, protein, O-antigen, and fimbrial synthetic genes. At 4 h, many cinnamaldehyde-induced repressive effects on E. coli O157:H7 gene expression were reversed, and cells became more motile and grew at a slightly higher rate. Data indicated that by 4 h, E. coli O157:H7 was able to convert cinnamaldehyde into the less toxic cinnamic alcohol using dehydrogenase/reductase enzymes (YqhD and DkgA). This is the first study to characterize the ability of E. coli O157:H7 to convert cinnamaldehyde into cinnamic alcohol which, in turn, showed that the antimicrobial activity of cinnamaldehyde is mainly attributable to its carbonyl aldehyde group.

  3. Examination of the Genome-Wide Transcriptional Response of Escherichia coli O157:H7 to Cinnamaldehyde Exposure

    PubMed Central

    Visvalingam, Jeyachchandran; Hernandez-Doria, Juan David

    2013-01-01

    Cinnamaldehyde is a natural antimicrobial that has been found to be effective against many food-borne pathogens, including Escherichia coli O157:H7. Although its antimicrobial effects have been well investigated, limited information is available on its effects at the molecular level. Sublethal treatment at 200 mg/liter cinnamaldehyde inhibited growth of E. coli O157:H7 at 37°C and for ≤2 h caused cell elongation, but from 2 to 4 h growth resumed and cells reverted to normal length. To understand this transient behavior, genome-wide transcriptional analysis of E. coli O157:H7 was performed at 2 and 4 h of exposure to cinnamaldehyde in conjunction with reverse-phase high-performance liquid chromatography (RP-HPLC) analysis for cinnamaldehyde and other cinnamic compounds. Drastically different gene expression profiles were obtained at 2 and 4 h. RP-HPLC analysis showed that cinnamaldehyde was structurally stable for at least 2 h. At 2 h of exposure, cinnamaldehyde induced expression of many oxidative stress-related genes and repressed expression of DNA, protein, O-antigen, and fimbrial synthetic genes. At 4 h, many cinnamaldehyde-induced repressive effects on E. coli O157:H7 gene expression were reversed, and cells became more motile and grew at a slightly higher rate. Data indicated that by 4 h, E. coli O157:H7 was able to convert cinnamaldehyde into the less toxic cinnamic alcohol using dehydrogenase/reductase enzymes (YqhD and DkgA). This is the first study to characterize the ability of E. coli O157:H7 to convert cinnamaldehyde into cinnamic alcohol which, in turn, showed that the antimicrobial activity of cinnamaldehyde is mainly attributable to its carbonyl aldehyde group. PMID:23183978

  4. Phenotypical analysis of the Lactobacillus rhamnosus GG fimbrial spaFED operon: surface expression and functional characterization of recombinant SpaFED pili in Lactococcus lactis.

    PubMed

    Rintahaka, Johanna; Yu, Xia; Kant, Ravi; Palva, Airi; von Ossowski, Ingemar

    2014-01-01

    A noticeable genomic feature of many piliated Gram-positive bacterial species is the presence of more than one pilus-encoding operon. Paradigmatically, the gut-adapted Lactobacillus rhamnosus GG strain contains two different fimbrial operons in its genome. However, whereas one of these operons (called spaCBA) is encoding for the functionally mucus-/collagen-binding SpaCBA pilus, for the other operon (called spaFED) any native expression of the SpaFED-called pili is still the subject of some uncertainty. Irrespective of such considerations, we decided it would be of relevance or interest to decipher the gross structure of this pilus type, and as well assess its functional capabilities for cellular adhesion and immunostimulation. For this, and by following the approach we had used previously to explicate the immuno-properties of SpaCBA pili, we constructed nisin-inducible expression clones producing either wild-type or SpaF pilin-deleted surface-assembled L. rhamnosus GG SpaFED pili on Lactococcus lactis cells. Using these piliated lactococcal constructs, we found that the pilin-polymerized architecture of a recombinant-produced SpaFED pilus coincides with sequence-based functional predictions of the related pilins, and in fact is prototypical of those other sortase-dependent pilus-like structures thus far characterized for piliated Gram-positive bacteria. Moreover, we confirmed that among the different pilin subunits encompassing spaFED operon-encoded pili, the SpaF pilin is a main adhesion determinant, and when present in the assembled structure can mediate pilus binding to mucus, certain extracellular matrix proteins, and different gut epithelial cell lines. However, somewhat unexpectedly, when recombinant SpaFED pili are surface-attached, we found that they could not potentiate the existing lactococcal cell-induced immune responses so elicited from intestinal- and immune-related cells, but rather instead, they could dampen them. Accordingly, we have now provided

  5. Phenotypical Analysis of the Lactobacillus rhamnosus GG Fimbrial spaFED Operon: Surface Expression and Functional Characterization of Recombinant SpaFED Pili in Lactococcus lactis

    PubMed Central

    Kant, Ravi; Palva, Airi; von Ossowski, Ingemar

    2014-01-01

    A noticeable genomic feature of many piliated Gram-positive bacterial species is the presence of more than one pilus-encoding operon. Paradigmatically, the gut-adapted Lactobacillus rhamnosus GG strain contains two different fimbrial operons in its genome. However, whereas one of these operons (called spaCBA) is encoding for the functionally mucus-/collagen-binding SpaCBA pilus, for the other operon (called spaFED) any native expression of the SpaFED-called pili is still the subject of some uncertainty. Irrespective of such considerations, we decided it would be of relevance or interest to decipher the gross structure of this pilus type, and as well assess its functional capabilities for cellular adhesion and immunostimulation. For this, and by following the approach we had used previously to explicate the immuno-properties of SpaCBA pili, we constructed nisin-inducible expression clones producing either wild-type or SpaF pilin-deleted surface-assembled L. rhamnosus GG SpaFED pili on Lactococcus lactis cells. Using these piliated lactococcal constructs, we found that the pilin-polymerized architecture of a recombinant-produced SpaFED pilus coincides with sequence-based functional predictions of the related pilins, and in fact is prototypical of those other sortase-dependent pilus-like structures thus far characterized for piliated Gram-positive bacteria. Moreover, we confirmed that among the different pilin subunits encompassing spaFED operon-encoded pili, the SpaF pilin is a main adhesion determinant, and when present in the assembled structure can mediate pilus binding to mucus, certain extracellular matrix proteins, and different gut epithelial cell lines. However, somewhat unexpectedly, when recombinant SpaFED pili are surface-attached, we found that they could not potentiate the existing lactococcal cell-induced immune responses so elicited from intestinal- and immune-related cells, but rather instead, they could dampen them. Accordingly, we have now provided

  6. Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections

    PubMed Central

    Vogeleer, Philippe; Tremblay, Yannick D. N.; Jubelin, Grégory; Jacques, Mario

    2015-01-01

    Forming biofilms may be a survival strategy of Shiga toxin-producing Escherichia coli to enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producing Escherichia coli isolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes, ehaB and espP, and two fimbrial genes, z1538 and lpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producing Escherichia coli but did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producing Escherichia coli and specifically seropathotype A isolates in the environment. PMID:26712549

  7. Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections.

    PubMed

    Vogeleer, Philippe; Tremblay, Yannick D N; Jubelin, Grégory; Jacques, Mario; Harel, Josée

    2015-12-28

    Forming biofilms may be a survival strategy of Shiga toxin-producing Escherichia coli to enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producing Escherichia coli isolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes, ehaB and espP, and two fimbrial genes, z1538 and lpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producing Escherichia coli but did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producing Escherichia coli and specifically seropathotype A isolates in the environment.

  8. The YfcO fimbriae gene enhances adherence and colonization abilities of avian pathogenic Escherichia coli in vivo and in vitro.

    PubMed

    Li, Yaxin; Wang, Haojin; Ren, Jianluan; Chen, Ling; Zhuge, Xiangkai; Hu, Lin; Li, Dezhi; Tang, Fang; Dai, Jianjun

    2016-11-01

    Chaperone-usher (CU) fimbriae, which are adhesive surface organelles found in many Gram-negative bacteria, mediate tissue tropism through the interaction of fimbrial adhesins with specific receptors expressed on the host cell surface. A CU fimbrial gene yfcO, was identified in avian pathogenic E. coli (APEC) strain DE205B via gene functional analysis. In this study, yfcO was found in 13.41% (11/82) of E. coli strains, including phylogenetic groups A, B1, B2 and D, with the highest percentage in group B2. The expression of yfcO in biofilm forming bacteria was significantly higher (P < 0.05) than that in the planktonic bacteria. A yfcO deletion mutant was constructed, and adherence to DF-1 chicken embryo fibroblast cells was analyzed in vitro. Compared to the wild-type (WT), adherence of the mutant to DF-1 cells was significantly decreased (P < 0.01). The mutant bacterial loads in the heart, brain and liver were significantly lower (P < 0.05) than those of the WT strain. Resistance of the mutant to acidic (acetic, pH 4.0, 20 min) and high osmolarity (2.5 M NaCl, 1 h) stress conditions decreased by 51.28% (P < 0.001) and 80.34% (P < 0.01), respectively. These results suggest that yfcO contributes to APEC virulence through bacterial adherence to host tissues.

  9. Structural and functional lesions in brush border of human polarized intestinal Caco-2/TC7 cells infected by members of the Afa/Dr diffusely adhering family of Escherichia coli.

    PubMed

    Peiffer, I; Guignot, J; Barbat, A; Carnoy, C; Moseley, S L; Nowicki, B J; Servin, A L; Bernet-Camard, M F

    2000-10-01

    Diffusely adhering Escherichia coli (DAEC) strains expressing F1845 fimbrial adhesin or Dr hemagglutinin belonging to the Afa/Dr family of adhesins infect cultured polarized human intestinal cells through recognition of the brush border-associated decay-accelerating factor (DAF; CD55) as a receptor. The wild-type Afa/Dr DAEC strain C1845 has been shown to induce brush border lesions by an adhesin-dependent mechanism triggering apical F-actin rearrangements. In the present study, we undertook to further characterize cell injuries following the interaction of wild-type Afa/Dr DAEC strains C1845 and IH11128 expressing fimbrial F1845 adhesin and Dr hemagglutinin, respectively, with polarized, fully differentiated Caco-2/TC7 cells. In both cases, bacterium-cell interaction was followed by rearrangement of the major brush border-associated cytoskeletal proteins F-actin, villin, and fimbrin, proteins which play a pivotal role in brush border assembly. In contrast, distribution of G-actin, actin-depolymerizing factor, and tubulin was not modified. Using draE mutants, we found that a mutant in which cysteine replaces aspartic acid at position 54 conserved binding capacity but failed to induce F-actin disassembly. Accompanying the cytoskeleton injuries, we found that the distribution of brush border-associated functional proteins sucrase-isomaltase (SI), dipeptidylpeptidase IV (DPPIV), glucose transporter SGLT1, and fructose transporter GLUT5 was dramatically altered. In parallel, SI and DPPIV enzyme activity decreased.

  10. E. Coli Infections

    MedlinePlus

    ... adults with weak immune systems. You can get E. coli infections by eating foods containing the bacteria. Symptoms of ... pool contaminated with human waste. Most cases of E. coli infection get better without treatment in 5 to 10 ...

  11. F9 fimbriae of uropathogenic Escherichia coli are expressed at low temperature and recognise Galβ1-3GlcNAc-containing glycans.

    PubMed

    Wurpel, Daniël J; Totsika, Makrina; Allsopp, Luke P; Hartley-Tassell, Lauren E; Day, Christopher J; Peters, Kate M; Sarkar, Sohinee; Ulett, Glen C; Yang, Ji; Tiralongo, Joe; Strugnell, Richard A; Jennings, Michael P; Schembri, Mark A

    2014-01-01

    Uropathogenic Escherichia coli (UPEC) is the leading causative agent of urinary tract infections (UTI) in the developed world. Among the major virulence factors of UPEC, surface expressed adhesins mediate attachment and tissue tropism. UPEC strains typically possess a range of adhesins, with type 1 fimbriae and P fimbriae of the chaperone-usher class the best characterised. We previously identified and characterised F9 as a new chaperone-usher fimbrial type that mediates biofilm formation. However, the regulation and specific role of F9 fimbriae remained to be determined in the context of wild-type clinical UPEC strains. In this study we have assessed the distribution and genetic context of the f9 operon among diverse E. coli lineages and pathotypes and demonstrated that f9 genes are significantly more conserved in a UPEC strain collection in comparison to the well-defined E. coli reference (ECOR) collection. In the prototypic UPEC strain CFT073, the global regulator protein H-NS was identified as a transcriptional repressor of f9 gene expression at 37°C through its ability to bind directly to the f9 promoter region. F9 fimbriae expression was demonstrated at 20°C, representing the first evidence of functional F9 fimbriae expression by wild-type E. coli. Finally, glycan array analysis demonstrated that F9 fimbriae recognise and bind to terminal Galβ1-3GlcNAc structures.

  12. The complete genome sequence of Escherichia coli EC958: a high quality reference sequence for the globally disseminated multidrug resistant E. coli O25b:H4-ST131 clone.

    PubMed

    Forde, Brian M; Ben Zakour, Nouri L; Stanton-Cook, Mitchell; Phan, Minh-Duy; Totsika, Makrina; Peters, Kate M; Chan, Kok Gan; Schembri, Mark A; Upton, Mathew; Beatson, Scott A

    2014-01-01

    Escherichia coli ST131 is now recognised as a leading contributor to urinary tract and bloodstream infections in both community and clinical settings. Here we present the complete, annotated genome of E. coli EC958, which was isolated from the urine of a patient presenting with a urinary tract infection in the Northwest region of England and represents the most well characterised ST131 strain. Sequencing was carried out using the Pacific Biosciences platform, which provided sufficient depth and read-length to produce a complete genome without the need for other technologies. The discovery of spurious contigs within the assembly that correspond to site-specific inversions in the tail fibre regions of prophages demonstrates the potential for this technology to reveal dynamic evolutionary mechanisms. E. coli EC958 belongs to the major subgroup of ST131 strains that produce the CTX-M-15 extended spectrum β-lactamase, are fluoroquinolone resistant and encode the fimH30 type 1 fimbrial adhesin. This subgroup includes the Indian strain NA114 and the North American strain JJ1886. A comparison of the genomes of EC958, JJ1886 and NA114 revealed that differences in the arrangement of genomic islands, prophages and other repetitive elements in the NA114 genome are not biologically relevant and are due to misassembly. The availability of a high quality uropathogenic E. coli ST131 genome provides a reference for understanding this multidrug resistant pathogen and will facilitate novel functional, comparative and clinical studies of the E. coli ST131 clonal lineage.

  13. Hemolysin and K antigens in relation to serotype and hemagglutination type of Escherichia coli isolated from extraintestinal infections.

    PubMed Central

    Evans, D J; Evans, D G; Höhne, C; Noble, M A; Haldane, E V; Lior, H; Young, L S

    1981-01-01

    Escherichia coli isolated from cases of bacteremia and from a variety of urinary tract infections were characterized according to serotype (O:H antigenicity), K type (possession of K1, K2, K3, K12, or K13), hemagglutination (HA) type, and production of beta-hemolysin. Results obtained with the bacteremia and urinary tract infection isolates were similar except for more hemolytic isolated from urine than from blood (42 versus 29%) and more K1+ isolates from blood than from urine (50 versus 29%). A close correlation was found between Ha type VI (production of fimbriae which mediate mannose-resistant HA of human and African green monkey erythrocytes) and the production of hemolysin or K1 capsular antigen or both. Most (95 of 98, or 95%) of the HA type VI+ blood isolates and most (146 of 164, or 89%) of the HA type VI+ urine isolates produced hemolysin or K1 or both, in contrast to 22 and 26%, respectively, of those belonging to HA types other than HA type VI. Also, 76% of all hemolytic and 70% of all K1+ isolates belonged to HA type VI. Remarkably few of the HA type VI+ isolates (13%) and even fewer of the HA type VI- isolates (3%) produced both K1 and hemolysin; these belonged mainly to serotypes O16:H6, O18:H7 and O2:H4. Other major serogroups were usually K1+/hemolysin- (O1, O7) or K1-/hemolysin+ (O2, O4, O6). At least 74% (262 of 351) and possibly as many as 83% (293 of 351) of those isolates which produced mannose-resistant HA of human erythrocytes were classified as HA type VI+; 31 isolates produced mannose-resistant HA with all erythrocytes tested. Taking serogroup and serotype into consideration, we conclude that the E. coli fimbrial hemagglutinin(s) responsible for the HA type VI phenotype will prove to be the same as the virulence-associated mannose-resistant adhesins of uropathogenic E. coli which other investigators have characterized as unique fimbrial antigens detectable by mannose-resistant HA of human erythrocytes. PMID:7007421

  14. Role of homologous recombination in adaptive diversification of extraintestinal Escherichia coli.

    PubMed

    Paul, Sandip; Linardopoulou, Elena V; Billig, Mariya; Tchesnokova, Veronika; Price, Lance B; Johnson, James R; Chattopadhyay, Sujay; Sokurenko, Evgeni V

    2013-01-01

    The contribution of homologous exchange (recombination) of core genes in the adaptive evolution of bacterial pathogens is not well understood. To investigate this, we analyzed fully assembled genomes of two Escherichia coli strains from sequence type 131 (ST131), a clonal group that is both the leading cause of extraintestinal E. coli infections and the main source of fluoroquinolone-resistant E. coli. Although the sequences of each of the seven multilocus sequence typing genes were identical in the two ST131 isolates, the strains diverged from one another by homologous recombination that affected at least 9% of core genes. This was on a par with the contribution to genomic diversity of horizontal gene transfer and point gene mutation. The genomic positions of recombinant and mobile genetic regions were partially linked, suggesting their concurrent occurrence. One of the genes affected by homologous recombination was fimH, which encodes mannose-specific type 1 fimbrial adhesin, resulting in functionally distinct copies of the gene in ST131 strains. One strain, a uropathogenic isolate, had a pathoadaptive variant of fimH that was acquired by homologous replacement into the commensal strain background. Close examination of FimH structure and function in additional ST131 isolates revealed that recombination led to acquisition of several functionally distinct variants that, upon homologous exchange, were targeted by a variety of pathoadaptive mutations under strong positive selection. Different recombinant fimH strains also showed a strong clonal association with ST131 isolates that had distinct fluoroquinolone resistance profiles. Thus, homologous recombination of core genes plays a significant role in adaptive diversification of bacterial pathogens, especially at the level of clonally related groups of isolates.

  15. In silico and in vivo studies of truncated forms of flagellin (FliC) of enteroaggregative Escherichia coli fused to FimH from uropathogenic Escherichia coli as a vaccine candidate against urinary tract infections.

    PubMed

    Savar, Nastaran Sadat; Jahanian-Najafabadi, Ali; Mahdavi, Mehdi; Shokrgozar, Mohammad Ali; Jafari, Anis; Bouzari, Saeid

    2014-04-10

    The new generation of vaccines against infectious diseases is based on recombinant fusion proteins. Flagellin (FliC) of enteroaggregative Escherichia coli (EAEC) could be considered as a potent adjuvant in designing new vaccines. However, because of its large size, incorporation of this protein with a vaccine antigen might negatively influence recognition of the vaccine epitopes by the immune system. Designing the truncated forms of FliC, capable of inducing innate immune response, enhances the immune responses to the target antigen. We have previously shown that two truncated forms of FliC are able to induce Interleukine-8 production in HT-29 epithelial cell line. In this study we designed recombinant vaccine against urinary tract infections (UTIs) using truncated forms of FliC and type 1 fimbrial FimH adhesin from uropathogenic Escherichia coli (UPEC) and studied their in silico interactions with Toll-like receptor 5 (TLR-5) via docking protocols. The best fusion protein was subjected to cloning and expression. The ability of the recombinant vaccine and the truncated forms in inducing immune responses was investigated. Our results showed that truncated forms are capable of inducing Th1 (forms A and B) and Th2 (form A) responses and fusion vaccine induced strong cellular and humoral immune responses.

  16. Escherichia coli biofilms

    PubMed Central

    Beloin, Christophe; Roux, Agnès; Ghigo, Jean-Marc

    2008-01-01

    Escherichia coli is a predominant species among facultative anaerobic bacteria of the gastrointestinal tract. Both its frequent community lifestyle and the availability of a wide array of genetic tools contributed to establish E. coli as a relevant model organism for the study of surface colonization. Several key factors, including different extracellular appendages, are implicated in E. coli surface colonization and their expression and activity are finely regulated, both in space and time, to ensure productive events leading to mature biofilm formation. This chapter will present known molecular mechanisms underlying biofilm development in both commensal and pathogenic E. coli. PMID:18453280

  17. pap-and pil-related DNA sequences and other virulence determinants associated with Escherichia coli isolated from septicemic chickens and turkeys.

    PubMed Central

    Dozois, C M; Fairbrother, J M; Harel, J; Bossé, M

    1992-01-01

    Escherichia coli isolates from septicemic or healthy chickens and turkeys from Quebec were serotyped, examined genotypically by using DNA probes specific for the pil and pap fimbrial systems and the aerobactin siderophore system, and examined phenotypically for lethality in day-old chicks, hemagglutination, serum resistance, and aerobactin production. Serogroups O78 and O1 were most common in septicemic chickens and turkeys. pap+ isolates from chickens were associated with septicemia, and pap+ isolates from turkeys were associated with lethality in day-old chicks. Four of nine pap+ isolates from septicemic turkeys expressed P adhesin, whereas all pap+ isolates from septicemic chickens were negative for P adhesin. The pil+ genotype was associated with septicemia in chickens and with serum resistance in isolates from turkeys. Mannose-sensitive hemagglutination of guinea pig erythrocytes was associated with septicemia in chickens and turkeys, although this phenotype was not associated with pil+ isolates from turkeys. Serum resistance was associated with isolates from septicemic turkeys and with lethality in isolates from chickens. The aerobactin system was associated with isolates from septicemic chickens and turkeys. Overall, results indicated that (i) genotypic examination may reveal virulence-associated traits which differ from the typically expected phenotype and/or are not readily expressed in vitro, and (ii) certain phenotypic and genotypic traits associated with E. coli causing extraintestinal disease in humans and animals are also associated with E. coli causing avian septicemia. PMID:1351879

  18. Identification of Enterohemorrhagic Escherichia coli O26:H− Genes Required for Intestinal Colonization in Calves

    PubMed Central

    van Diemen, Pauline M.; Dziva, Francis; Stevens, Mark P.; Wallis, Timothy S.

    2005-01-01

    Enterohemorrhagic Escherichia coli (EHEC) infections in humans are an important public health problem and are commonly acquired via contact with ruminant feces. The serogroups that are predominantly associated with human infection in the United States and Europe are O157 and O26. Serotypes O157:H7 and O26:H− differ in their virulence and tissue tropism in calves and therefore may colonize calves by distinct mechanisms. The mechanisms underlying EHEC intestinal colonization and pathogenesis are poorly understood. Signature-tagged mutagenesis was used to identify 59 genes of EHEC O26:H− that are required for the intestinal colonization of calves. Our results indicate important roles for locus of enterocyte effacement (LEE)-encoded type III secreted proteins in intestinal colonization. In addition, colonization is facilitated by cytotoxins, putative type III secreted proteins unlinked to the LEE, a putative fimbrial operon, and numerous genes involved in central metabolism and transport and genes of unknown function. Our data also imply that the elaboration of type I fimbriae by EHEC O26:H− is disadvantageous for persistence within the bovine intestines. These observations have important implications for the design of vaccines to control these important zoonotic pathogens. PMID:15731074

  19. Oral administration of protease inhibits enterotoxigenic Escherichia coli receptor activity in piglet small intestine.

    PubMed Central

    Mynott, T L; Luke, R K; Chandler, D S

    1996-01-01

    The virulence of enterotoxigenic Escherichia coli (ETEC) is attributed to their ability to adhere via fimbrial adhesins to specific receptors located on the intestinal mucosa. A novel approach to preventing ETEC induced diarrhoea would be to prevent attachment of ETEC to intestine by proteolytically modifying the receptor attachment sites. This study aimed to examine the effect of bromelain, a proteolytic extract obtained from pineapple stems, on ETEC receptor activity in porcine small intestine. Bromelain was administered orally to piglets and K88+ ETEC attachment to small intestine was measured at 50 cm intervals using an enzyme immunoassay. K88+ ETEC attachment to intestinal sections that were not treated with bromelain varied appreciably between sampling sites. Variability in receptor activity along the intestinal surface is though to be caused by the localised effects of endogenous proteases. Oral administration of exogenous protease inhibited K88+ ETEC attachment to pig small intestine in a dose dependent manner (p < 0.05). Attachment of K88+ ETEC was negligible after treatment, resembling the levels of attachment of K88 to piglets of the genetically determined non-adhesive phenotype, which are resistant to K88+ ETEC infection. Serum biochemical analysis and histopathological examination of treated piglets showed no adverse effects of the bromelain treatment. It is concluded that administration of bromelain can inhibit ETEC receptor activity in vivo and may therefore be useful for prevention of K88+ ETEC induced diarrhoea. PMID:8566855

  20. Genotypic analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs in Iran.

    PubMed

    Ghanbarpour, Reza; Askari, Nasrin; Ghorbanpour, Masoud; Tahamtan, Yahya; Mashayekhi, Khoobyar; Afsharipour, Narjes; Darijani, Nasim

    2017-03-01

    The aim of the present study was to determine the analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs. Two hundred ninety E. coli isolates were recovered from 300 rectal swabs of diarrheic lambs and were confirmed by biochemical tests. The pathotype determination was done according to the presence of genes including f5, f41, LTI, STI, bfp, ipaH, stx 1 , stx 2 , eae, ehlyA, cnf 1 , cnf 2 , cdIII, cdIV, and f17 by PCR method. Sixty-six isolates (23.72%) possessed the STI gene and categorized into entrotoxigenic E. coli (ETEC). Nine isolates (3.1%) and five isolates (1.72%) were positive for the cnf1 and cnf2 genes which categorized into necrotoxic E. coli (NTEC). Hundred and seventeen isolates (40.34%) harbored stx 1 and/or stx 2 and classified as Shiga toxin-producing E. coli (STEC). Thirteen isolates (4.48%) were assigned to atypical entropathogenic E. coli (aEPEC) and possessed eae gene. Two isolates (0.68%) were positive for ipaH gene and were assigned to entroinvasive E. coli (EIEC). Statistical analysis showed a specific association between eae gene and STEC pathotype (P < 0.0001). The most prevalent resistance was observed against lincomycin (96.5%) and the lowest resistance was against kanamycine (56.02%), respectively. The high prevalence of STEC and ETEC indicates that diarrheic lambs represent an important reservoir for humans. ETEC may play an important role for frequent occurrence of diarrhea in lambs observed in this region. Due to high antibiotic resistance, appropriate control should be implemented in veterinary medicine to curb the development of novel resistant isolates.

  1. PATHOGENIC ESCHERICHIA COLI

    EPA Science Inventory

    Escherichia coli is a bacterial species which inhabits the gastrointestinal tract of man and warm-blooded animals. Because of the ubiquity of this bacterium in the intestinal flora, it serves as an important indicator organism of fecal contamination. E. coli, aside from serving a...

  2. Pathogenic Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli, a member of the Enterobacteriaceae family, is a part of the normal flora of the intestinal tract of humans and a variety of animals. E. coli strains are classified on the basis of antigenic differences in two surface components (serotyping), the somatic antigen (O) of the lipopoly...

  3. Diarrheagenic Escherichia coli.

    PubMed

    Gomes, Tânia A T; Elias, Waldir P; Scaletsky, Isabel C A; Guth, Beatriz E C; Rodrigues, Juliana F; Piazza, Roxane M F; Ferreira, Luís C S; Martinez, Marina B

    2016-12-01

    Most Escherichia coli strains live harmlessly in the intestines and rarely cause disease in healthy individuals. Nonetheless, a number of pathogenic strains can cause diarrhea or extraintestinal diseases both in healthy and immunocompromised individuals. Diarrheal illnesses are a severe public health problem and a major cause of morbidity and mortality in infants and young children, especially in developing countries. E. coli strains that cause diarrhea have evolved by acquiring, through horizontal gene transfer, a particular set of characteristics that have successfully persisted in the host. According to the group of virulence determinants acquired, specific combinations were formed determining the currently known E. coli pathotypes, which are collectively known as diarrheagenic E. coli. In this review, we have gathered information on current definitions, serotypes, lineages, virulence mechanisms, epidemiology, and diagnosis of the major diarrheagenic E. coli pathotypes.

  4. Whole-Genome Analysis of Antimicrobial-Resistant and Extraintestinal Pathogenic Escherichia coli in River Water.

    PubMed

    Gomi, Ryota; Matsuda, Tomonari; Matsumura, Yasufumi; Yamamoto, Masaki; Tanaka, Michio; Ichiyama, Satoshi; Yoneda, Minoru

    2017-03-01

    Contamination of surface waters by antimicrobial-resistant bacteria and pathogenic bacteria is a great concern. In this study, 531 Escherichia coli isolates obtained from the Yamato River in Japan were evaluated phenotypically for resistance to 25 antimicrobials. Seventy-six isolates (14.3%) were multidrug resistant (MDR), 66 (12.4%) were nonsusceptible to one or two classes of agents, and 389 (73.3%) were susceptible. We performed whole-genome sequencing of selected strains by using Illumina technology. In total, the genome sequences of 155 strains were analyzed for antibiotic resistance determinants and phylogenetic characteristics. More than 50 different resistance determinants, including acquired resistance genes and chromosomal resistance mutations, were detected. Among the sequenced MDR strains (n = 66), sequence type 155 (ST155) complex (n = 9), ST10 complex (n = 9), and ST69 complex (n = 7) were prevalent. Among extraintestinal pathogenic E. coli (ExPEC) strains (n = 58), clinically important clonal groups, namely, ST95 complex (n = 18), ST127 complex (n = 8), ST12 complex (n = 6), ST14 complex (n = 6), and ST131 complex (n = 6), were prevalent, demonstrating the clonal distribution of environmental ExPEC strains. Typing of the fimH (type 1 fimbrial adhesin) gene revealed that ST131 complex strains carried fimH22 or fimH41, and no strains belonging to the fimH30 subgroup were detected. Fine-scale phylogenetic analysis and virulence gene content analysis of strains belonging to the ST95 complex (one of the major clonal ExPEC groups causing community-onset infections) revealed no significant differences between environmental and clinical strains. The results indicate contamination of surface waters by E. coli strains belonging to clinically important clonal groups.IMPORTANCE The prevalence of antimicrobial-resistant and pathogenic E. coli strains in surface waters is a concern because surface waters are used as sources for drinking water, irrigation, and

  5. Virulence factors and antimicrobial resistance of escherichia coli isolated from urinary tract of swine in southern of Brazil

    PubMed Central

    da Costa, Mateus Matiuzzi; Drescher, Guilherme; Maboni, Franciele; Weber, Shana; de Avila Botton, Sônia; Vainstein, Marilene Henning; Schrank, Irene Silveira; de Vargas, Agueda Castagna

    2008-01-01

    The present study determined the molecular and resistance patterns of E. coli isolates from urinary tract of swine in Southern of Brazil. Molecular characterization of urinary vesicle samples was performed by PCR detection of virulence factors from ETEC, STEC and UPEC. From a total of 82 E. coli isolates, 34 (38.63%) harbored one or more virulence factors. The frequency of virulence factors genes detected by PCR were: pap (10.97%), hlyA (10.97%), iha (9.75%), lt (8.53%), sta (7.31%) sfa (6.09%), f4 (4.87%), f5 (4.87%), stb (4.87%), f6 (1.21%) and f41 (1.21%). Isolates were resistant to penicillin (95.12%), lincomycin (93.9%), erythromycin (92.68%), tetracycline (90.24%), amoxicillin (82.92%), ampicillin (74.39%), josamycin (79.26%), norfloxacin (58.53%), enrofloxacin (57.31%), gentamicin (39.02%), neomycin (37.8%), apramycin (30.48%), colistine (30.48%) and cefalexin (6.09%). A number of 32 (39.02%) E. coli isolates harbored plasmids. PMID:24031300

  6. Transcriptional analysis of the MrpJ network: modulation of diverse virulence-associated genes and direct regulation of mrp fimbrial and flhDC flagellar operons in Proteus mirabilis.

    PubMed

    Bode, Nadine J; Debnath, Irina; Kuan, Lisa; Schulfer, Anjelique; Ty, Maureen; Pearson, Melanie M

    2015-06-01

    The enteric bacterium Proteus mirabilis is associated with a significant number of catheter-associated urinary tract infections (UTIs). Strict regulation of the antagonistic processes of adhesion and motility, mediated by fimbriae and flagella, respectively, is essential for disease progression. Previously, the transcriptional regulator MrpJ, which is encoded by the mrp fimbrial operon, has been shown to repress both swimming and swarming motility. Here we show that MrpJ affects an array of cellular processes beyond adherence and motility. Microarray analysis found that expression of mrpJ mimicking levels observed during UTIs leads to differential expression of 217 genes related to, among other functions, bacterial virulence, type VI secretion, and metabolism. We probed the molecular mechanism of transcriptional regulation by MrpJ using transcriptional reporters and chromatin immunoprecipitation (ChIP). Binding of MrpJ to two virulence-associated target gene promoters, the promoters of the flagellar master regulator flhDC and mrp itself, appears to be affected by the condensation state of the native chromosome, although both targets share a direct MrpJ binding site proximal to the transcriptional start. Furthermore, an mrpJ deletion mutant colonized the bladders of mice at significantly lower levels in a transurethral model of infection. Additionally, we observed that mrpJ is widely conserved in a collection of recent clinical isolates. Altogether, these findings support a role of MrpJ as a global regulator of P. mirabilis virulence.

  7. Detection of pap, sfa, afa, foc, and fim Adhesin-Encoding Operons in Uropathogenic Escherichia coli Isolates Collected From Patients With Urinary Tract Infection

    PubMed Central

    Rahdar, Masoud; Rashki, Ahmad; Miri, Hamid Reza; Rashki Ghalehnoo, Mehdi

    2015-01-01

    Background: Uropathogenic Escherichia coli (UPEC) with its virulence factors is the most prevalent cause of urinary tract infection (UTI). Objectives; This study aimed to determine the occurrence of fim, pap, sfa, and afa genes among 100 UPEC isolates collected from patients diagnosed with UTI. Materials and Methods A total of 100 UPEC isolates were obtained from urine samples of patients with UTI. The prevalence of 5 virulence genes encoding type 1 fimbriae (fimH), pili associated with pyelonephritis (pap), S and F1C fimbriae (sfa and foc) and afimbrial adhesins (afa) were determined through PCR method. We also investigated the phylogenetic background of all isolates. In addition, the distribution of adhesin-encoding operons between the phylogroups was assessed. Results: The prevalence of genes encoding for fimbrial adhesive systems was 95% for fim, 57% for pap, 16% for foc, and 81% for sfa. The operons encoding for afa afimbrial adhesins were identified in 12% of isolates. The various combinations of detected genes were designated as virulence patterns. The fim gene, which occurred in strains from all phylogenetic groups (A, B1, B2, and D) was evaluated and no significant differences were found among these groups. Conversely, significant differences were observed in relation to pap, afa, foc, and sfa operons. Conclusions: These results indicate that the PCR method is a powerful genotypic assay for the detection of adhesin-encoding operons. Thus, this assay can be recommended for clinical use to detect virulent urinary E. coli strains, as well as epidemiological studies. PMID:26464770

  8. Afa/Dr diffusely adhering Escherichia coli infection in T84 cell monolayers induces increased neutrophil transepithelial migration, which in turn promotes cytokine-dependent upregulation of decay-accelerating factor (CD55), the receptor for Afa/Dr adhesins.

    PubMed

    Bétis, Fréderic; Brest, Patrick; Hofman, Véronique; Guignot, Julie; Kansau, Imad; Rossi, Bernard; Servin, Alain; Hofman, Paul

    2003-04-01

    Ulcerative colitis and Crohn's disease are inflammatory bowel diseases thought to involve strains of Escherichia coli. We report here that two wild-type Afa/Dr diffusely adhering E. coli (DAEC) strains, C1845 and IH11128, which harbor the fimbrial F1845 adhesin and the Dr hemagglutinin, respectively, and the E. coli laboratory strain HB101, transformed with the pSSS1 plasmid to produce Afa/Dr F1845 adhesin, all induced interleukin-8 (IL-8) production and transepithelial migration of polymorphonuclear leukocytes (PMNL) in polarized monolayers of the human intestinal cell line T84 grown on semipermeable filters. We observed that after PMNL migration, expression of decay-accelerating factor (DAF, or CD55), the brush border-associated receptor for Afa/Dr adhesins, was strongly enhanced, increasing the adhesion of Afa/Dr DAEC bacteria. When examining the mechanism by which DAF expression was enhanced, we observed that the PMNL transepithelial migration induced epithelial synthesis of tumor necrosis factor alpha and IL-1beta, which in turn promoted the upregulation of DAF.

  9. Different Cellular Origins and Functions of Extracellular Proteins from Escherichia coli O157:H7 and O104:H4 as Determined by Comparative Proteomic Analysis

    PubMed Central

    Islam, Nazrul; Nagy, Attila; Garrett, Wesley M.; Shelton, Dan

    2016-01-01

    ABSTRACT Extracellular proteins play important roles in bacterial interactions with the environmental matrices. In this study, we examined the extracellular proteins from Escherichia coli O157:H7 and O104:H4 by tandem mass spectrometry. We identified 500 and 859 proteins from the growth media of E. coli O157:H7 and O104:H4, respectively, including 371 proteins common to both strains. Among proteins that were considered specific to E. coli O157:H7 or present at higher relative abundances in O157:H7 medium, most (57 of 65) had secretion signal sequences in their encoding genes. Noticeably, the proteins included locus of enterocyte effacement (LEE) virulence factors, proteins required for peptidyl-lipoprotein accumulation, and proteins involved in iron scavenging. In contrast, a much smaller proportion of proteins (37 of 150) that were considered specific to O104:H4 or presented at higher relative abundances in O104:H4 medium had signals targeting them for secretion. These proteins included Shiga toxin 2 subunit B and O104:H4 signature proteins, including AAF/1 major fimbrial subunit and serine protease autotransporters. Most of the abundant proteins from the growth medium of E. coli O104:H4 were annotated as having functions in the cytoplasm. We provide evidence that the extensive presence of cytoplasmic proteins in E. coli O104:H4 growth medium was due to biological processes independent of cell lysis, indicating alternative mechanisms for this potent pathogen releasing cytoplasmic contents into the growth milieu, which could play a role in interaction with the environmental matrices, such as pathogenesis and biofilm formation. IMPORTANCE In this study, we compared the extracellular proteins from two of the most prominent foodborne pathogenic E. coli organisms that have caused severe outbreaks in the United States and in Europe. E. coli O157:H7 is a well-studied Shiga toxigenic foodborne pathogen of the enterohemorrhagic pathotype that has caused numerous outbreaks

  10. Enhancing E. coli isobutanol tolerance through engineering its global transcription factor cAMP receptor protein (CRP).

    PubMed

    Chong, Huiqing; Geng, Hefang; Zhang, Hongfang; Song, Hao; Huang, Lei; Jiang, Rongrong

    2014-04-01

    The limited isobutanol tolerance of Escherichia coli is a major drawback during fermentative isobutanol production. Different from classical strain engineering approaches, this work was initiated to improve E. coli isobutanol tolerance from its transcriptional level by engineering its global transcription factor cAMP receptor protein (CRP). Random mutagenesis libraries were generated by error-prone PCR of crp, and the libraries were subjected to isobutanol stress for selection. Variant IB2 (S179P, H199R) was isolated and exhibited much better growth (0.18 h(-1) ) than the control (0.05 h(-1) ) in 1.2% (v/v) isobutanol (9.6 g/L). Genome-wide DNA microarray analysis revealed that 58 and 308 genes in IB2 had differential expression (>2-fold, p < 0.05) in the absence and presence of 1% (v/v) isobutanol, respectively. When challenged with isobutanol, genes related to acid resistance (gadABCE, hdeABD), nitrate reduction (narUZYWV), flagella and fimbrial activity (lfhA, yehB, ycgR, fimCDF), and sulfate reduction and transportation (cysIJH, cysC, cysN) were the major functional groups that were up-regulated, whereas most of the down-regulated genes were enzyme (tnaA) and transporters (proVWX, manXYZ). As demonstrated by single-gene knockout experiments, gadX, nirB, rhaS, hdeB, and ybaS were found associated with strain isobutanol resistance. The intracellular reactive oxygen species (ROS) level in IB2 was only half of that of the control when facing stress, indicating that IB2 can withstand toxic isobutanol much better than the control.

  11. Functional Heterogeneity of the UpaH Autotransporter Protein from Uropathogenic Escherichia coli

    PubMed Central

    Allsopp, Luke P.; Beloin, Christophe; Moriel, Danilo Gomes; Totsika, Makrina; Ghigo, Jean-Marc

    2012-01-01

    Uropathogenic Escherichia coli (UPEC) is responsible for the majority of urinary tract infections (UTI). To cause a UTI, UPEC must adhere to the epithelial cells of the urinary tract and overcome the shear flow forces of urine. This function is mediated primarily by fimbrial adhesins, which mediate specific attachment to host cell receptors. Another group of adhesins that contributes to UPEC-mediated UTI is autotransporter (AT) proteins. AT proteins possess a range of virulence properties, such as adherence, aggregation, invasion, and biofilm formation. One recently characterized AT protein of UPEC is UpaH, a large adhesin-involved-in-diffuse-adherence (AIDA-I)-type AT protein that contributes to biofilm formation and bladder colonization. In this study we characterized a series of naturally occurring variants of UpaH. We demonstrate that extensive sequence variation exists within the passenger-encoding domain of UpaH variants from different UPEC strains. This sequence variation is associated with functional heterogeneity with respect to the ability of UpaH to mediate biofilm formation. In contrast, all of the UpaH variants examined retained a conserved ability to mediate binding to extracellular matrix (ECM) proteins. Bioinformatic analysis of the UpaH passenger domain identified a conserved region (UpaHCR) and a hydrophobic region (UpaHHR). Deletion of these domains reduced biofilm formation but not the binding to ECM proteins. Despite variation in the upaH sequence, the transcription of upaH was repressed by a conserved mechanism involving the global regulator H-NS, and mutation of the hns gene relieved this repression. Overall, our findings shed new light on the regulation and functions of the UpaH AT protein. PMID:22904291

  12. sRNA-Mediated Regulation of P-Fimbriae Phase Variation in Uropathogenic Escherichia coli

    PubMed Central

    Khandige, Surabhi; Kronborg, Tina; Uhlin, Bernt Eric; Møller-Jensen, Jakob

    2015-01-01

    Uropathogenic Escherichia coli (UPEC) are capable of occupying physiologically distinct intracellular and extracellular niches within the urinary tract. This feat requires the timely regulation of gene expression and small RNAs (sRNAs) are known to mediate such rapid adjustments in response to changing environmental cues. This study aimed to uncover sRNA-mediated gene regulation in the UPEC strain UTI89, during infection of bladder epithelial cells. Hfq is an RNA chaperone known to facilitate and stabilize sRNA and target mRNA interactions with bacterial cells. The co-immunoprecipitation and high throughput RNA sequencing of Hfq bound sRNAs performed in this study, revealed distinct sRNA profiles in UPEC in the extracellular and intracellular environments. Our findings emphasize the importance of studying regulatory sRNAs in a biologically relevant niche. This strategy also led to the discovery of a novel virulence-associated trans-acting sRNA—PapR. Deletion of papR was found to enhance adhesion of UTI89 to both bladder and kidney cell lines in a manner independent of type-1 fimbriae. We demonstrate PapR mediated posttranscriptional repression of the P-fimbriae phase regulator gene papI and postulate a role for such regulation in fimbrial cross-talk at the population level in UPEC. Our results further implicate the Leucine responsive protein (LRP) as a transcriptional activator regulating PapR expression. Our study reports, for the first time, a role for sRNAs in regulation of P-fimbriae phase variation and emphasizes the importance of studying pathogenesis-specific sRNAs within a relevant biological niche. PMID:26291711

  13. Transcriptional regulation of the ecp operon by EcpR, IHF, and H-NS in attaching and effacing Escherichia coli.

    PubMed

    Martínez-Santos, Verónica I; Medrano-López, Abraham; Saldaña, Zeus; Girón, Jorge A; Puente, José L

    2012-09-01

    Enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli are clinically important diarrheagenic pathogens that adhere to the intestinal epithelial surface. The E. coli common pili (ECP), or meningitis-associated and temperature-regulated (MAT) fimbriae, are ubiquitous among both commensal and pathogenic E. coli strains and play a role as colonization factors by promoting the interaction between bacteria and host epithelial cells and favoring interbacterial interactions in biofilm communities. The first gene of the ecp operon encodes EcpR (also known as MatA), a proposed regulatory protein containing a LuxR-like C-terminal helix-turn-helix (HTH) DNA-binding motif. In this work, we analyzed the transcriptional regulation of the ecp genes and the role of EcpR as a transcriptional regulator. EHEC and EPEC ecpR mutants produce less ECP, while plasmids expressing EcpR increase considerably the expression of EcpA and production of ECP. The ecp genes are transcribed as an operon from a promoter located 121 bp upstream of the start codon of ecpR. EcpR positively regulates this promoter by binding to two TTCCT boxes distantly located upstream of the ecp promoter, thus enhancing expression of downstream ecp genes, leading to ECP production. EcpR mutants in the putative HTH DNA-binding domain are no longer able to activate ecp expression or bind to the TTCCT boxes. EcpR-mediated activation is aided by integration host factor (IHF), which is essential for counteracting the repression exerted by histone-like nucleoid-structuring protein (H-NS) on the ecp promoter. This work demonstrates evidence about the interplay between a novel member of a diverse family of regulatory proteins and global regulators in the regulation of a fimbrial operon.

  14. The effects of upaB deletion and the double/triple deletion of upaB, aatA, and aatB genes on pathogenicity of avian pathogenic Escherichia coli.

    PubMed

    Zhu-Ge, Xiang-Kai; Pan, Zi-Hao; Tang, Fang; Mao, Xiang; Hu, Lin; Wang, Shao-Hui; Xu, Bin; Lu, Cheng-Ping; Fan, Hong-Jie; Dai, Jian-Jun

    2015-12-01

    Autotransporters (ATs) are associated with pathogenesis of Avian Pathogenic Escherichia coli (APEC). The molecular characterization of APEC ATs can provide insights about their relevance to APEC pathogenesis. Here, we characterized a conventional autotransporter UpaB in APEC DE205B genome. The upaB existed in 41.9 % of 236 APEC isolates and was predominantly associated with ECOR B2 and D. Our studies showed that UpaB mediates the DE205B adhesion in DF-1 cells, and enhances autoaggregation and biofilm formation of fimbria-negative E. coli AAEC189 (MG1655Δfim) in vitro. Deletion of upaB of DE205B attenuates the virulence in duck model and early colonization in the duck lungs during APEC systemic infection. Furthermore, double and triple deletion of upaB, aatA, and aatB genes cumulatively attenuated DE205B adhesion in DF-1 cells, accompanying with decreased 50 % lethal dose (LD50) in duck model and the early colonization in the duck lungs. However, DE205BΔupaB/ΔaatA/ΔaatB might "compensate" the influence of gene deletion by upregulating the expression of fimbrial adhesin genes yqiL, yadN, and vacuolating autotransporter vat during early colonization of APEC. Finally, we demonstrated that vaccination with recombinant UpaB, AatA, and AatB proteins conferred protection against colisepticemia caused by DE205B infection in duck model.

  15. The Afa/Dr adhesins of diffusely adhering Escherichia coli stimulate interleukin-8 secretion, activate mitogen-activated protein kinases, and promote polymorphonuclear transepithelial migration in T84 polarized epithelial cells.

    PubMed

    Bétis, Fréderic; Brest, Patrick; Hofman, Véronique; Guignot, Julie; Bernet-Camard, Marie-Françoise; Rossi, Bernard; Servin, Alain; Hofman, Paul

    2003-03-01

    Afa/Dr diffusely adhering Escherichia coli (Afa/Dr DAEC) strains cause symptomatic urinary tract and intestinal infections. The proinflammatory effects of Afa/Dr DAEC strains in vitro have been not investigated to date. In the present study, we used confluent polarized monolayers of intestinal cell line T84 to evaluate the consequences of epithelial infection by Afa/Dr DAEC strains in terms of proinflammatory response. Polymorphonuclear leukocyte (PMNL) migration across the epithelial barrier was induced after incubation of the T84 monolayers with the wild-type Afa/Dr DAEC strain C1845 harboring the fimbrial F1845 adhesin and strain IH11128 harboring the Dr hemagglutinin, and the E. coli laboratory strain HB101 was transformed with the pSSS1 plasmid, producing Afa/Dr F1845 adhesin. PMNL migrations were correlated with a basolateral secretion of interleukin-8 by T84 cells and were abolished after incubation of epithelial cells with an anti-decay accelerating factor (DAF) antibody that recognized the short consensus repeat 3 domain of DAF (monoclonal antibody 1H4). Moreover, Afa/Dr DAEC strains induced tyrosine phosphorylation of several T84 proteins and activated the mitogen-activated protein kinases (ERK1/2 mitogen-activated protein, P38, and Jun-C kinases). These data demonstrated for the first time that, in vitro, Afa/Dr DAEC strains exert a proinflammatory signal in intestinal epithelial cells.

  16. Investigation of E. coli Enterotoxins.

    DTIC Science & Technology

    1976-08-01

    It has been determined that representative culture filtrates from two different strains (H197 and 74-114) of enterotoxigenic E . coli contain at least...for E . coli entorotoxin (soluble) and that trypsin-activated insol ECT is more antigenic than unactivated insol ECT. In contrast, it was determined...that cholera (ga) toxoid, with or without adjuvant, stimulates antitoxin capable of neutralizing both cholera and E . coli enterotoxins. It has been

  17. Human Gut-Commensalic Lactobacillus ruminis ATCC 25644 Displays Sortase-Assembled Surface Piliation: Phenotypic Characterization of Its Fimbrial Operon through In Silico Predictive Analysis and Recombinant Expression in Lactococcus lactis

    PubMed Central

    Yu, Xia; Lyytinen, Outi; Kant, Ravi; Åvall-Jääskeläinen, Silja; von Ossowski, Ingemar; Palva, Airi

    2015-01-01

    Sortase-dependent surface pili (or fimbriae) in Gram-positive bacteria are well documented as a key virulence factor for certain harmful opportunistic pathogens. However, it is only recently known that these multi-subunit protein appendages are also belonging to the “friendly” commensals and now, with this new perspective, they have come to be categorized as a niche-adaptation factor as well. In this regard, it was shown earlier that sortase-assembled piliation is a native fixture of two human intestinal commensalics (i.e., Lactobacillus rhamnosus and Bifidobacterium bifidum), and correspondingly where the pili involved have a significant role in cellular adhesion and immunomodulation processes. We now reveal that intestinal indigenous (or autochthonous) Lactobacillus ruminis is another surface-piliated commensal lactobacillar species. Heeding to in silico expectations, the predicted loci for the LrpCBA-called pili are organized tandemly in the L. ruminis genome as a canonical fimbrial operon, which then encodes for three pilin-proteins and a single C-type sortase enzyme. Through electron microscopic means, we showed that these pilus formations are a surface assemblage of tip, basal, and backbone pilin subunits (respectively named LrpC, LrpB, and LrpA) in L. ruminis, and also when expressed recombinantly in Lactococcus lactis. As well, by using the recombinant-piliated lactococci, we could define certain ecologically relevant phenotypic traits, such as the ability to adhere to extracellular matrix proteins and gut epithelial cells, but also to effectuate an induced dampening on Toll-like receptor 2 signaling and interleukin-8 responsiveness in immune-related cells. Within the context of the intestinal microcosm, by wielding such niche-advantageous cell-surface properties the LrpCBA pilus would undoubtedly have a requisite functional role in the colonization dynamics of L. ruminis indigeneity. Our study provides only the second description of a native

  18. Inhibition and Reversal of Microbial Attachment by an Antibody with Parasteric Activity against the FimH Adhesin of Uropathogenic E. coli

    PubMed Central

    Friend, Della; Jalan, Aachal; Gupta, Shivani; Interlandi, Gianluca; Liu, Yan; Tchesnokova, Veronika; Rodriguez, Victoria B.; Sumida, John P.; Strong, Roland K.; Wu, Xue-Ru; Thomas, Wendy E.; Sokurenko, Evgeni V.

    2015-01-01

    Attachment proteins from the surface of eukaryotic cells, bacteria and viruses are critical receptors in cell adhesion or signaling and are primary targets for the development of vaccines and therapeutic antibodies. It is proposed that the ligand-binding pocket in receptor proteins can shift between inactive and active conformations with weak and strong ligand-binding capability, respectively. Here, using monoclonal antibodies against a vaccine target protein - fimbrial adhesin FimH of uropathogenic Escherichia coli, we demonstrate that unusually strong receptor inhibition can be achieved by antibody that binds within the binding pocket and displaces the ligand in a non-competitive way. The non-competitive antibody binds to a loop that interacts with the ligand in the active conformation of the pocket but is shifted away from ligand in the inactive conformation. We refer to this as a parasteric inhibition, where the inhibitor binds adjacent to the ligand in the binding pocket. We showed that the receptor-blocking mechanism of parasteric antibody differs from that of orthosteric inhibition, where the inhibitor replaces the ligand or allosteric inhibition where the inhibitor binds at a site distant from the ligand, and is very potent in blocking bacterial adhesion, dissolving surface-adherent biofilms and protecting mice from urinary bladder infection. PMID:25974133

  19. Pre- and post-weaning scours in southeastern Australia: A survey of 22 commercial pig herds and characterisation of Escherichia coli isolates

    PubMed Central

    Van Breda, Lechelle K.; Dhungyel, Om P.; Ginn, Andrew N.; Iredell, Jonathan R.; Ward, Michael P.

    2017-01-01

    Diarrhoeal diseases in piglets caused by Escherichia coli are responsible for substantial losses each year in the Australian pig industry. A cross-sectional survey was conducted (September 2013–May 2014) across 22 commercial pig herds located in southeastern Australia: NSW (n = 9); VIC (n = 10); and SA (n = 3), to estimate the prevalence of E. coli associated diarrhoea in pre- and post-weaned piglets and to identify key risk factors associated with E. coli disease. A questionnaire on management and husbandry practices was included. Faecal samples (n = 50 from each herd) were tested for the presence of β-haemolytic E. coli. Species level identification was confirmed by matrix-assisted laser desorption / ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). ETEC virulence and enterotoxin genes (F4, F5, F6, F18, F41, STa, STb and LT) were screened for by multiplex PCR. This study assessed 60 potential risk factors for E. coli disease in post-weaned piglets, with 2 key factors–recent disease events and the presence of bedding, statistically associated with the presence of post-weaning scours. The prevalence of diarrhea in pre-weaned pens was 17% (16/93), compared with 24% (24/102) in post-weaned pens. The most prevalent β-haemolytic ETEC genes were F18 (32%) and STb (32%) but isolates were more likely to contain F4:STb (11 of 22 herds, 23%), than F18:STb (5 of 22 herds, 6%). These findings indicate that recent disease events that have occurred within the last 12 months, and by the use of bedding or not maintaining fresh bedding can have significant impacts on piglet diarrhoea. PMID:28273152

  20. ANIMAL ENTEROTOXIGENIC ESCHERICHIA COLI

    PubMed Central

    Dubreuil, J. Daniel; Isaacson, Richard E.; Schifferli, Dieter M.

    2016-01-01

    Enterotoxigenic Escherichia coli (ETEC) is the most common cause of E. coli diarrhea in farm animals. ETEC are characterized by the ability to produce two types of virulence factors; adhesins that promote binding to specific enterocyte receptors for intestinal colonization and enterotoxins responsible for fluid secretion. The best-characterized adhesins are expressed in the context of fimbriae, such as the F4 (also designated K88), F5 (K99), F6 (987P), F17 and F18 fimbriae. Once established in the animal small intestine, ETEC produces enterotoxin(s) that lead to diarrhea. The enterotoxins belong to two major classes; heat-labile toxin that consist of one active and five binding subunits (LT), and heat-stable toxins that are small polypeptides (STa, STb, and EAST1). This chapter describes the disease and pathogenesis of animal ETEC, the corresponding virulence genes and protein products of these bacteria, their regulation and targets in animal hosts, as well as mechanisms of action. Furthermore, vaccines, inhibitors, probiotics and the identification of potential new targets identified by genomics are presented in the context of animal ETEC. PMID:27735786

  1. Epigenetic Influence of Dam Methylation on Gene Expression and Attachment in Uropathogenic Escherichia coli

    PubMed Central

    Stephenson, Stacy Ann-Marie; Brown, Paul D.

    2016-01-01

    Urinary tract infections (UTI) are among the most frequently encountered infections in clinical practice globally. Predominantly a burden among female adults and infants, UTIs primarily caused by uropathogenic Escherichia coli (UPEC) results in high morbidity and fiscal health strains. During pathogenesis, colonization of the urinary tract via fimbrial adhesion to mucosal cells is the most critical point in infection and has been linked to DNA methylation. Furthermore, with continuous exposure to antibiotics as the standard therapeutic strategy, UPEC has evolved to become highly adaptable in circumventing the effect of antimicrobial agents and host defenses. Hence, the need for alternative treatment strategies arises. Since differential DNA methylation is observed as a critical precursor to virulence in various pathogenic bacteria, this body of work sought to assess the influence of the DNA adenine methylase (dam) gene on gene expression and cellular adhesion in UPEC and its potential as a therapeutic target. To monitor the influence of dam on attachment and FQ resistance, selected UPEC dam mutants created via one-step allelic exchange were transformed with cloned qnrA and dam complement plasmid for comparative analysis of growth rate, antimicrobial susceptibility, biofilm formation, gene expression, and mammalian cell attachment. The absence of DNA methylation among dam mutants was apparent. Varying deficiencies in cell growth, antimicrobial resistance and biofilm formation, alongside low-level increases in gene expression (recA and papI), and adherence to HEK-293 and HTB-9 mammalian cells were also detected as a factor of SOS induction to result in increased mutability. Phenotypic characteristics of parental strains were restored in dam complement strains. Dam’s vital role in DNA methylation and gene expression in local UPEC isolates was confirmed. Similarly to dam-deficient Enterohemorrhagic E. coli (EHEC), these findings suggest unsuccessful therapeutic use

  2. Epigenetic Influence of Dam Methylation on Gene Expression and Attachment in Uropathogenic Escherichia coli.

    PubMed

    Stephenson, Stacy Ann-Marie; Brown, Paul D

    2016-01-01

    Urinary tract infections (UTI) are among the most frequently encountered infections in clinical practice globally. Predominantly a burden among female adults and infants, UTIs primarily caused by uropathogenic Escherichia coli (UPEC) results in high morbidity and fiscal health strains. During pathogenesis, colonization of the urinary tract via fimbrial adhesion to mucosal cells is the most critical point in infection and has been linked to DNA methylation. Furthermore, with continuous exposure to antibiotics as the standard therapeutic strategy, UPEC has evolved to become highly adaptable in circumventing the effect of antimicrobial agents and host defenses. Hence, the need for alternative treatment strategies arises. Since differential DNA methylation is observed as a critical precursor to virulence in various pathogenic bacteria, this body of work sought to assess the influence of the DNA adenine methylase (dam) gene on gene expression and cellular adhesion in UPEC and its potential as a therapeutic target. To monitor the influence of dam on attachment and FQ resistance, selected UPEC dam mutants created via one-step allelic exchange were transformed with cloned qnrA and dam complement plasmid for comparative analysis of growth rate, antimicrobial susceptibility, biofilm formation, gene expression, and mammalian cell attachment. The absence of DNA methylation among dam mutants was apparent. Varying deficiencies in cell growth, antimicrobial resistance and biofilm formation, alongside low-level increases in gene expression (recA and papI), and adherence to HEK-293 and HTB-9 mammalian cells were also detected as a factor of SOS induction to result in increased mutability. Phenotypic characteristics of parental strains were restored in dam complement strains. Dam's vital role in DNA methylation and gene expression in local UPEC isolates was confirmed. Similarly to dam-deficient Enterohemorrhagic E. coli (EHEC), these findings suggest unsuccessful therapeutic use of

  3. Investigation of E. coli Enterotoxins.

    DTIC Science & Technology

    In the course of investigating E . coli enterotoxins, it was discovered that trypsin treatment of partially purified enterotoxin from strain H197 (078...loops) did exhibit elevated PF titers compared with uninoculated controls. These findings are consistent with the hypothesis that E . coli enterotoxins

  4. Thiophene metabolism by E. coli

    SciTech Connect

    Clark, D.P.

    1990-01-01

    The objective of this project is to investigate the mechanism of degradation of sulfur containing heterocyclic molecules by mutants of Escherichia coli K-12. We previously isolated multiple mutants of E. coli which were selected for improved oxidation of furan and thiophene derivatives. We have focused on the thdA mutation in our subsequent research as it appears to be of central importance in thiophene oxidation. We hope that analysis of the thd gene of E. coli will lead to improvement of our thiophene metabolizing bacterial strains.

  5. Presence of pap-, sfa-, and afa-related sequences in necrotoxigenic Escherichia coli isolates from cattle: evidence for new variants of the AFA family.

    PubMed

    Mainil, J G; Jacquemin, E; Hérault, F; Oswald, E

    1997-07-01

    Necrotoxigenic Escherichia coli (NTEC) are associated with intestinal and extraintestinal diseases in animals and human beings and produce Cytotoxic Necrotizing Factor 1 (CNF1) or 2 (CNF2). Fourty-three NTEC1, 42 NTEC2, and 32 CNF-negative isolates from cattle were tested by colony DNA hybridization, by plasmid DNA hybridization and by PCR assays for the presence of DNA sequences homologous to the operons coding for fimbrial (PAP/PRS, SFA/FIC, and F17) and afimbrial (AFA/Dr) adhesins of extraintestinal E. coli. Most NTEC1 isolates hybridized with the PAP probes and either the SFA probe (37%) or the AFA probes (49%). Most NTEC2 isolates, in contrast, hybridized with the F17 probe (45%), the AFA probes (19%), or the F17 and AFA probes (22%). A probe-positive plasmid was identified in each of the 19 NTEC2 isolates studied. They all hybridized with the CNF2 toxin probe (Vir plasmids) and most of them with the F17 (6 plasmids) or AFA (7 plasmids) probes. PCR amplification was obtained with 6 of the 11 NTEC isolates tested for the papGII/prsG genes; with all 5 NTEC isolates tested for the sfa and related operons; but with none of the 18 NTEC isolates tested for the afa and related operons. pap-, sfa-, and afa-related sequences are thus present in NTEC isolates from cattle in addition to f17-related operons and may code for adhesins corresponding to specific colonization factors. f17- and afa-related sequences can be located on the Vir plasmids along with the cnf2 gene. Existence of new variants of the AFA/Dr family is evident from the negative results of this family-specific PCR assay.

  6. Human Body Temperature (37°C) Increases the Expression of Iron, Carbohydrate, and Amino Acid Utilization Genes in Escherichia coli K-12▿

    PubMed Central

    White-Ziegler, Christine A.; Malhowski, Amy J.; Young, Sarah

    2007-01-01

    Using DNA microarrays, we identified 126 genes in Escherichia coli K-12 whose expression is increased at human body temperature (37°C) compared to growth at 23°C. Genes involved in the uptake and utilization of amino acids, carbohydrates, and iron dominated the list, supporting a model in which temperature serves as a host cue to increase expression of bacterial genes needed for growth. Using quantitative real-time PCR, we investigated the thermoregulatory response for representative genes in each of these three categories (hisJ, cysP, srlE, garP, fes, and cirA), along with the fimbrial gene papB. Increased expression at 37°C compared to 23°C was retained in both exponential and stationary phases for all of the genes and in most of the various media tested, supporting the relative importance of this cue in adapting to changing environments. Because iron acquisition is important for both growth and virulence, we analyzed the regulation of the iron utilization genes cirA and fes and found that growth in iron-depleted medium abrogated the thermoregulatory effect, with high-level expression at both temperatures, contrasting with papB thermoregulation, which was not greatly altered by limiting iron levels. A positive role for the environmental regulator H-NS was found for fes, cirA, hisJ, and srlE transcription, whereas it had a primarily negative effect on cysP and garP expression. Together, these studies indicate that temperature is a broadly used cue for regulating gene expression in E. coli and that H-NS regulates iron, carbohydrate, and amino acid utilization gene expression. PMID:17526711

  7. Mucosal and systemic immune responses in patients with diarrhea due to CS6-expressing enterotoxigenic Escherichia coli.

    PubMed

    Qadri, Firdausi; Ahmed, Tanvir; Ahmed, Firoz; Bhuiyan, M Saruar; Mostofa, Mohammad Golam; Cassels, Frederick J; Helander, Anna; Svennerholm, Ann-Mari

    2007-05-01

    Colonization factor CS6 expressed by enterotoxigenic Escherichia coli (ETEC) is a nonfimbrial polymeric protein. A substantial proportion of ETEC strains isolated from patients in endemic settings and in people who travel to regions where ETEC is endemic are ETEC strains expressing CS6, either alone or in combination with fimbrial colonization factor CS5 or CS4. However, relatively little is known about the natural immune responses elicited against CS6 expressed by ETEC strains causing disease. We studied patients who were hospitalized with diarrhea (n = 46) caused by CS6-expressing ETEC (ETEC expressing CS6 or CS5 plus CS6) and had a disease spectrum ranging from severe dehydration (27%) to moderate or mild dehydration (73%). Using recombinant CS6 antigen, we found that more than 90% of the patients had mucosal immune responses to CS6 expressed as immunoglobulin (IgA) antibody-secreting cells (ASC) or antibody in lymphocyte supernatant (ALS) and that about 57% responded with CS6-specific IgA antibodies in feces. More than 80% of the patients showed IgA seroconversion to CS6. Significant increases in the levels of anti-CS6 antibodies of the IgG isotype were also observed in assays for ASC (75%), ALS (100%), and serum (70%). These studies demonstrated that patients hospitalized with the noninvasive enteric pathogen CS6-expressing ETEC responded with both mucosal and systemic antibodies against CS6. Studies are needed to determine if the anti-CS6 responses protect against reinfection and if protective levels of CS6 immunity are induced by vaccination.

  8. Antimicrobial resistance and molecular characterization of virulence genes, phylogenetic groups of Escherichia coli isolated from diarrheic and healthy camel-calves in Tunisia.

    PubMed

    Bessalah, Salma; Fairbrother, John Morris; Salhi, Imed; Vanier, Ghyslaine; Khorchani, Touhami; Seddik, Mouldi Mabrouk; Hammadi, Mohamed

    2016-12-01

    This study was conducted to determine the prevalence of virulence genes, serogroups, antimicrobial resistance and phylogenetic groups of Escherichia coli strains isolated from diarrheic and healthy camel calves in Tunisia. From 120 fecal samples (62 healthy and 58 diarrheic camel calves aged less than 3 months), 70 E. coli isolates (53 from diarrheic herds and 17 from healthy herds) were examined by PCR for detection of the virulence genes associated with pathogenic E. coli in animals. A significantly greater frequency of the f17 gene was observed in individual camels and in herds with diarrhea, this gene being found in 44.7% and 41.5% of isolates from camels and herds with diarrhea versus 22.5% and 11.7% in camels (p=0.05) and herds without diarrhea (p=0.02). The aida, cnf1/2, f18, stx2 and paa genes were found only in isolates from camels with diarrhea, although at a low prevalence, 1.8%, 3.7%, 1.8%, 3.7% and 11.3%, respectively. Prevalence of afa8, cdtB, eae, east1, iroN, iss, kpsMTII, paa, sfa, tsh and papC genes did not differ significantly between herds with or without diarrhea. Genes coding for faeG, fanC, f41, estI, estII, CS31a and eltA were not detected in any isolates. All isolates were sensitive to amikacin, chloramphenicol, ciprofloxacin, gentamicin and ceftiofur and the highest frequency of resistance was observed to tetracycline, and ampicillin (52.8% and 37.1% respectively). The phylogenetic groups were identified by conventional triplex PCR. Results showed that E. coli strains segregated mainly in phylogenetic group B1, 52.8% in diarrheic herds and 52.9% in healthy herds.

  9. Detection of bacteria and fungi and assessment of the molecular aspects and resistance of Escherichia coli isolated from confiscated passerines intended for reintroduction programs.

    PubMed

    Braconaro, Patricia; Saidenberg, André B S; Benites, Nilson R; Zuniga, Eveline; da Silva, Adriana M J; Sanches, Thais C; Zwarg, Ticiana; Brandão, Paulo E; Melville, Priscilla A

    2015-11-01

    Many native bird species are currently considered rare in Brazil because they have been indiscriminately collected by animal traffickers and commercialized, leading to dwindling numbers in their natural habitats. Confiscated animals are at times destined for reintroduction programs that must ensure these animals do not pose a risk to native populations. Healthy or sick wild passerines may carry a great diversity of microorganisms. Therefore, knowledge of the sanitary status of confiscated animals destined for reintroduction is critical to assess whether these animals act as microorganism carriers and to investigate the epidemiology of transmissible diseases, a crucial aspect for animal and human health preservation. This study examined the occurrence of aerobic and facultative anaerobic bacteria and fungi in cloacal swabs collected from wild confiscated passerines intended for reintroduction programs. In vitro susceptibility tests of the most frequent isolates as well as studies of the molecular aspects of Escherichia coli isolates were also performed. There was microorganism growth in 62.5% of 253 samples. The microorganisms that were most frequently isolated were Staphylococcus spp. (15.0%), Micrococcus spp. (11.5%), E. coli (10.7%) and Klebsiella spp. (10.7%). Fifteen bacteria genera and seven fungi genera were isolated. Multidrug-resistance to antimicrobials was observed in Staphylococcus spp., Micrococcus spp., E. coli and Klebsiella spp. isolates. The high occurrence of Enterobacteria observed is possibly related to the sanitary conditions in which confiscated animals are usually kept. One E. coli sample (out of 27 isolates) was positive for the S-fimbrial adhesion encoding gene (sfa). Considering the low occurrence of genes that encode virulence factors, confiscated passerines may represent a low risk for the potential transmission of EPEC, APEC, UPEC and NMEC isolates to other animals or humans. The potential risk of intra- or inter-specific transmission of

  10. Colonization of the small intestine of weaned pigs by enterotoxigenic Escherichia coli that lack known colonization factors.

    PubMed

    Nagy, B; Arp, L H; Moon, H W; Casey, T A

    1992-05-01

    Intestinal colonization of 3-week-old weaned pigs by enterotoxigenic Escherichia coli (ETEC) strains that were originally isolated from weaned pigs with fatal diarrhea and that lacked K88, K99, F41, and 987P adhesins (4P- ETEC) was studied by histologic, immunofluorescent, and electron microscopic techniques. In the first experiment, 16 principal pigs were inoculated orogastrically with ETEC strain 2134 (serogroup O157: H19) or 2171 (serogroup 0141:H4), and eight control pigs were not inoculated. In the second experiment, 24 principals were inoculated with ETEC strain 2134, and 12 controls were inoculated with a nonenterotoxigenic strain of E. coli. Principal and control pigs were necropsied at intervals from 24 to 72 hours after inoculation of principals to provide the tissues used for this report. Results from the two experiments and with both ETEC strains were similar and therefore were combined. Adhesion by 4P- ETEC was demonstrated in ileum but not in cecum or colon in 22/40 principal pigs sampled at 24 to 72 hours after orogastric inoculation. Adherent bacteria were most apparent on the intestinal villi covering Peyer's patches. Only occasional adherent bacteria were detected in ileal sections from a few (4/20) of the control pigs. Adherence by 4P- ETEC was characterized by "patches" of bacteria closely associated with the lateral surfaces and less frequently with the tips and the bases of intact villi. In most cases, the adherent bacteria were separated from epithelial cell microvilli and other bacterial cells by a 50-400-nm space. Filamentous bacterial appendages bridged this space and formed a network among adjacent bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Pathogenic Lifestyles of E. coli Pathotypes in a Standardized Epithelial Cell Model Influence Inflammatory Signaling Pathways and Cytokines Secretion

    PubMed Central

    Sanchez-Villamil, Javier; Tapia-Pastrana, Gabriela; Navarro-Garcia, Fernando

    2016-01-01

    Inflammatory response is key for the host defense against diarrheagenic Escherichia coli and contributes to the pathogenesis of the disease but there is not a comparative study among different diarrheagenic pathotypes. We analyzed the inflammatory response induced by five diarrheagenic pathotypes in a HT-29 cell infection model. The model was unified to reproduce the pathogenesis of each pathotype. To compare the inflammatory responses we evaluated: (i) nuclear NF-κB and ERK1/2 translocation by confocal microscopy; (ii) kinetics of activation by each pathway detecting p65 and ERK1/2 phosphorylation by Western blotting; (iii) pathways modulation through bacterial infections with or without co-stimulation with TNF-α or EGF; (iv) cytokine profile induced by each pathotype with and without inhibitors of each pathway. EHEC but mainly EPEC inhibited translocation and activation of p65 and ERK1/2 pathways, as well as cytokines secretion; inhibition of p65 and ERK1/2 phosphorylation prevailed in the presence of TNF-α and EGF, respectively. Intracellular strains, EIEC/Shigella flexneri, caused a strong translocation, activation, and cytokines secretion but they could not inhibit TNF-α and EGF stimulation. ETEC and mainly EAEC caused a moderate translocation, but a differential activation, and high cytokines secretion; interestingly TNF-α and EGF stimulation did no modify p65 and ERK1/2 activation. The use of inhibitors of NF-κB and/or ERK1/2 showed that NF-κB is crucial for cytokine induction by the different pathotypes; only partially depended on ERK1/2 activation. Thus, in spite of their differences, the pathotypes can also be divided in three groups according to their inflammatory response as those (i) that inject effectors to cause A/E lesion, which are able to inhibit NF-κB and ERK1/2 pathways, and cytokine secretion; (ii) with fimbrial adherence and toxin secretion with a moderate inhibition of both pathways but high cytokines secretion through autocrine

  12. Experimental evolution of E. coli

    NASA Astrophysics Data System (ADS)

    Zhang, Mengshi

    The evolution from unicellular to multicellular behavior is an essential step in the history of life. Our aim is to investigate the emergence of collective behavior in the model organism Escherichia coli (E. coli) and its selection advantages, such as better utilization of public goods. Our preliminary results suggest that the evolution of collective behavior may be a natural response to stressed conditions. Mailing address: Room 306 Science Centre North Block, The Chinese University of Hong Kong, Shatin, N.T. Hong Kong SAR. Phone: +852-3943-6354. Fax: +852-2603-5204. E-mail: mengshi0928@gmail.com.

  13. Serogroups of Escherichia coli from drinking water.

    PubMed

    Ramteke, P W; Tewari, Suman

    2007-07-01

    Fifty seven isolates of thermotolerant E. coli were recovered from 188 drinking water sources, 45 (78.9%) were typable of which 15 (26.3%) were pathogenic serotypes. Pathogenic serogroup obtained were 04 (Uropathogenic E. coli, UPEC), 025 (Enterotoxigenic E. coli, ETEC), 086 (Enteropathogenic E. coli, EPEC), 0103 (Shiga-toxin producing E. coli, STEC), 0157 (Shiga-toxin producing E. coli, STEC), 08 (Enterotoxigenic E. coli, ETEC) and 0113 (Shiga-toxin producing E. coli, STEC). All the pathogenic serotypes showed resistance to bacitracin and multiple heavy metal ions. Resistance to streptomycin and cotrimazole was detected in two strains whereas resistance to cephaloridine, polymixin-B and ampicillin was detected in one strain each. Transfer of resistances to drugs and metallic ions was observed in 9 out of 12 strains studied. Resistances to bacitracin were transferred in all nine strains. Among heavy metals resistance to As(3+) followed by Cr(6+) were transferred more frequently.

  14. In-stream Escherichia coli Modeling

    NASA Astrophysics Data System (ADS)

    Pandey, P.; Soupir, M.

    2013-12-01

    Elevated levels of pathogenic bacteria indicators such as Escherichia coli (E. coli) in streams are a serious concern. Controlling E. coli levels in streams requires improving our existing understanding of fate and transport of E. coli at watershed scale. In-stream E. coli concentrations are potentially linked to non-point pollution sources (i.e., agricultural land). Water of a natural stream can receive E. coli by either through overland flow (via runoff from cropland) or resuspension from the streambed to the water column. Calculating in-stream total E. coli loads requires estimation of particle attached bacteria as well free floating E. coli transport. Currently water quality models commonly used for predicting E. coli levels in stream water have limited capability for predicting E. coli levels in the water column as well as in the streambed sediment. The challenges in calculating in-stream E. coli levels include difficulties in modeling the complex interactions between sediment particles and E. coli. Here we have developed a watershed scale model (integrated with Soil and Water Assessment Tool (SWAT)), which involves calculation of particle attached E. coli, to predict in-stream E. coli concentrations. The proposed model predicts E. coli levels in streambed bed sediment as well as in the water column. An extensive in-stream E. coli monitoring was carried out to verify the model predictions, and results indicate that the model performed well. The study proposed here will improve understanding on in-stream bacterial contamination, and help improving existing water quality models for predicting pathogenic bacteria levels in ambient water bodies.

  15. Investigation of ’Escherichia coli’ Enterotoxins

    DTIC Science & Technology

    1978-05-01

    E . coli diarrheal disease in man and domestic animals. Fundamentally, the design of the vaccine is based on the well- documented ability of cholera antitoxin to neutralize both cholera and heat- labile E . coli enterotoxins and on the ability of certain E . coli antigens to enhance the immune response to cholera toxoid and possibly whole-cell Cholera Vaccine, as

  16. Exonuclease IX of Escherichia coli.

    PubMed Central

    Shafritz, K M; Sandigursky, M; Franklin, W A

    1998-01-01

    The bacteria Escherichia coli contains several exonucleases acting on both double- and single-stranded DNA and in both a 5'-->3' and 3'-->5' direction. These enzymes are involved in replicative, repair and recombination functions. We have identified a new exonuclease found in E.coli, termed exonuclease IX, that acts preferentially on single-stranded DNA as a 3'-->5' exonuclease and also functions as a 3'-phosphodiesterase on DNA containing 3'-incised apurinic/apyrimidinic (AP) sites to remove the product trans -4-hydroxy-2-pentenal 5-phosphate. The enzyme showed essentially no activity as a deoxyribophosphodiesterase acting on 5'-incised AP sites. The activity was isolated as a glutathione S-transferase fusion protein from a sequence of the E.coli genome that was 60% identical to a 260 bp region of the small fragment of the DNA polymerase I gene. The protein has a molecular weight of 28 kDa and is free of AP endonuclease and phosphatase activities. Exonuclease IX is expressed in E.coli , as demonstrated by reverse transcription-PCR, and it may function in the DNA base excision repair and other pathways. PMID:9592142

  17. Afa/Dr-expressing, diffusely adhering Escherichia coli strain C1845 triggers F1845 fimbria-dependent phosphatidylserine externalization on neutrophil-like differentiated PLB-985 cells through an apoptosis-independent mechanism.

    PubMed

    Sémiramoth, Nicolas; Gleizes, Aude; Turbica, Isabelle; Sandré, Catherine; Marin-Esteban, Viviana; Gorges, Roseline; Servin, Alain; Chollet-Martin, Sylvie

    2010-07-01

    The enterovirulent Escherichia coli strains potentially involved in inflammatory bowel diseases include diffusely adherent strains expressing Afa/Dr fimbriae (Afa/Dr DAEC). We have previously observed type 1 pilus-mediated interleukin-8 (IL-8) hyperproduction in infected neutrophils. As pathogen induction of host cell death programs and clearance of apoptotic infected cells are crucial for innate immune system homeostasis and host integrity, we examined modulation of neutrophil cell death by Afa/Dr DAEC. Using the human PLB-985 cell line differentiated into fully mature neutrophils, we found that the wild-type enterovirulent E. coli strain C1845 and the recombinant strain DH5alpha/pF1845 (expressing the fimbrial adhesin F1845) similarly induced time-dependent phosphatidylserine (PS) externalization, suggesting a major specific role of this virulence factor. Using small interfering RNA (siRNA) decay-accelerating factor (DAF)-transfected PLB-985 cells, we then showed that this PS externalization was triggered in part by glycosylphosphatidylinositol (GPI)-anchored DAF receptor engagement (leading to tyrosine kinase and protein kinase C activation) and that it required cytoskeleton and lipid raft architectural integrity. PS externalization under these conditions was not dependent on caspases, mitochondria, lysosomes, or reactive oxygen or nitrogen species. F1845-mediated PS externalization was sufficient to enable macrophage engulfment of infected differentiated PLB-985 cells. These findings provide new insights into the neutrophil response to Afa/Dr DAEC infection and highlight a new role for F1845 fimbriae. Interestingly, although apoptosis pathways were not engaged, C1845-infected PLB-985 cells displayed enhanced removal by macrophages, a process that may participate in the resolution of Afa/Dr DAEC infection and related inflammation.

  18. Impairments in enzyme activity and biosynthesis of brush border-associated hydrolases in human intestinal Caco-2/TC7 cells infected by members of the Afa/Dr family of diffusely adhering Escherichia coli.

    PubMed

    Peiffer, I; Bernet-Camard, M F; Rousset, M; Servin, A L

    2001-05-01

    Wild-type diffusely adhering Escherichia coli (DAEC) harbouring afimbrial adhesin (Afa) or fimbrial Dr and F1845 adhesins (Afa/Dr DAEC) apically infecting the human intestinal epithelial cells promote injuries in the brush border of the cells. We report here that infection by Afa/Dr DAEC wild-type strains C1845 and IH11128 in polarized human fully differentiated Caco-2/TC7 cells dramatically impaired the enzyme activity of functional brush border-associated proteins sucrase-isomaltase (SI) and dipeptidylpeptidase IV (DPP IV). Blockers of the transduction signal molecules, previously found to be active against the Afa/Dr DAEC-induced cytoskeleton injury, were inactive against the Afa/Dr-induced decrease in sucrase enzyme activity. In parallel, Afa/Dr DAEC infection promotes the blockade of the biosynthesis of SI and DPP IV without affection enzyme stability. The observation that no changes occurred in mRNA levels of SI and DPP IV upon infection suggested that the decrease in biosynthesis probably resulted from a decrease in the translation rate. When the cells were infected with recombinant E. coli strains expressing homologous adhesins of the wild-type strains, neither a decrease in sucrase and DPP IV enzyme activities nor an inhibition of enzyme biosynthesis were observed. In conclusion, taken together, these data give new insights into the mechanisms by which the wild-type Afa/Dr DAEC strains induce functional injuries in polarized fully differentiated human intestinal cells. Moreover, the results revealed that other pathogenic factor(s) distinct from the Afa/Dr adhesins may play(s) a crucial role in this mechanism of pathogenicity.

  19. Dietary specific antibodies in spray-dried immune plasma prevent enterotoxigenic Escherichia coli F4 (ETEC) post weaning diarrhoea in piglets.

    PubMed

    Niewold, T A; van Dijk, A J; Geenen, P L; Roodink, H; Margry, R; van der Meulen, J

    2007-10-06

    In order to establish the mechanism of spray dried plasma powder (SDPP) in improving pig health and performance, a diet containing either 8% SDPP, spray dried immune plasma powder (SDIPP), or control protein (soybean and whey) ration was fed to piglets in an experimental model of enterotoxigenic Escherichia coli F4 (ETEC) post-weaning diarrhoea (PWD). SDIPP was obtained from pigs immunized with a vaccine containing ETEC fimbrial subunit F4 and heat-labile toxin (LT), and SDPP from non-immunized controls. Average daily growth (ADG) was determined, and daily samples of rectal faeces were assessed for diarrhoea (as percentage of dry matter), and ETEC excretion (in CFU/g). SDPP and SDIPP significantly (p<0.05) reduced diarrhoea, and SDIPP significantly reduced ETEC excretion. ADG was not significantly (p>0.05) affected. After the experiment, 30% of piglets tested F4 receptor positive (F4R+). A significant correlation between F4R status and morbidity was found. In F4R+ animals, SDIPP significantly improved diarrhoea and ADG, and decreased ETEC excretion, and SDPP significantly improved diarrhoea and ADG. Surprisingly, SDPP reduced diarrhoea in F4R+ animals without significant reduction of ETEC excretion, which is most likely related to the presence of anti-LT antibodies in SDPP. The results show that oral protection against ETEC by SDPP is attributable to spontaneous antibodies, in this case anti-LT antibodies. Furthermore, the results indicate that the combination of anti-LT and anti-F4 antibodies as in SDIPP is most effective in ETEC prevention. Finally, the F4R distribution in the herd should be taken into account to correctly assess efficacy.

  20. Curli Temper Adherence of Escherichia coli O157:H7 to Squamous Epithelial Cells from the Bovine Recto-Anal Junction in a Strain-Dependent Manner.

    PubMed

    Kudva, Indira T; Carter, Michelle Q; Sharma, Vijay K; Stasko, Judith A; Giron, Jorge A

    2017-01-01

    Our recent studies have shown that intimin and the locus of enterocyte effacement-encoded proteins do not play a role in Escherichia coli O157:H7 (O157) adherence to the bovine recto-anal junction squamous epithelial (RSE) cells. To define factors that play a contributory role, we investigated the role of curli, fimbrial adhesins commonly implicated in adherence to various fomites and plant and human epithelial cells, in O157 adherence to RSE cells. Specifically, we examined (i) wild-type strains of O157; (ii) curli variants of O157 strains; (iii) isogenic curli deletion mutants of O157; and (iv) adherence inhibition of O157 using anti-curlin sera. Results of these experiments conducted under stringent conditions suggest that curli do not solely contribute to O157 adherence to RSE cells and in fact demonstrate a modulating effect on O157 adherence to RSE cells in contrast to HEp-2 cells (human epidermoid carcinoma of the larynx cells with HeLa contamination). The absence of curli and presence of blocking anti-curli antibodies enhanced O157-RSE cell interactions among some strains, thus alluding to a spatial, tempering effect of curli on O157 adherence to RSE cells when present. At the same time, the presence or absence of curli did not alter RSE cell adherence patterns of another O157 strain. These observations are at variance with the reported role of curli in O157 adherence to human cell lines such as HEp-2 and need to be factored in when developing anti-adherence modalities for preharvest control of O157 in cattle.

  1. Effects of lng Mutations on LngA Expression, Processing, and CS21 Assembly in Enterotoxigenic Escherichia coli E9034A.

    PubMed

    Saldaña-Ahuactzi, Zeus; Rodea, Gerardo E; Cruz-Córdova, Ariadnna; Rodríguez-Ramírez, Viridiana; Espinosa-Mazariego, Karina; González-Montalvo, Martín A; Ochoa, Sara A; González-Pedrajo, Bertha; Eslava-Campos, Carlos A; López-Villegas, Edgar O; Hernández-Castro, Rigoberto; Arellano-Galindo, José; Patiño-López, Genaro; Xicohtencatl-Cortes, Juan

    2016-01-01

    Enterotoxigenic Escherichia coli (ETEC) is a major cause of morbidity in children under 5 years of age in low- and middle-income countries and a leading cause of traveler's diarrhea worldwide. The ability of ETEC to colonize the intestinal epithelium is mediated by fimbrial adhesins, such as CS21 (Longus). This adhesin is a type IVb pilus involved in adherence to intestinal cells in vitro and bacterial self-aggregation. Fourteen open reading frames have been proposed to be involved in CS21 assembly, hitherto only the lngA and lngB genes, coding for the major (LngA) and minor (LngB) structural subunit, have been characterized. In this study, we investigated the role of the LngA, LngB, LngC, LngD, LngH, and LngP proteins in the assembly of CS21 in ETEC strain E9034A. The deletion of the lngA, lngB, lngC, lngD, lngH, or lngP genes, abolished CS21 assembly in ETEC strain E9034A and the adherence to HT-29 cells was reduced 90%, compared to wild-type strain. Subcellular localization prediction of CS21 proteins was similar to other well-known type IV pili homologs. We showed that LngP is the prepilin peptidase of LngA, and that ETEC strain E9034A has another peptidase capable of processing LngA, although with less efficiency. Additionally, we present immuno-electron microscopy images to show that the LngB protein could be localized at the tip of CS21. In conclusion, our results demonstrate that the LngA, LngB, LngC, LngD, LngH, and LngP proteins are essential for CS21 assembly, as well as for bacterial aggregation and adherence to HT-29 cells.

  2. Effects of lng Mutations on LngA Expression, Processing, and CS21 Assembly in Enterotoxigenic Escherichia coli E9034A

    PubMed Central

    Saldaña-Ahuactzi, Zeus; Rodea, Gerardo E.; Cruz-Córdova, Ariadnna; Rodríguez-Ramírez, Viridiana; Espinosa-Mazariego, Karina; González-Montalvo, Martín A.; Ochoa, Sara A.; González-Pedrajo, Bertha; Eslava-Campos, Carlos A.; López-Villegas, Edgar O.; Hernández-Castro, Rigoberto; Arellano-Galindo, José; Patiño-López, Genaro; Xicohtencatl-Cortes, Juan

    2016-01-01

    Enterotoxigenic Escherichia coli (ETEC) is a major cause of morbidity in children under 5 years of age in low- and middle-income countries and a leading cause of traveler's diarrhea worldwide. The ability of ETEC to colonize the intestinal epithelium is mediated by fimbrial adhesins, such as CS21 (Longus). This adhesin is a type IVb pilus involved in adherence to intestinal cells in vitro and bacterial self-aggregation. Fourteen open reading frames have been proposed to be involved in CS21 assembly, hitherto only the lngA and lngB genes, coding for the major (LngA) and minor (LngB) structural subunit, have been characterized. In this study, we investigated the role of the LngA, LngB, LngC, LngD, LngH, and LngP proteins in the assembly of CS21 in ETEC strain E9034A. The deletion of the lngA, lngB, lngC, lngD, lngH, or lngP genes, abolished CS21 assembly in ETEC strain E9034A and the adherence to HT-29 cells was reduced 90%, compared to wild-type strain. Subcellular localization prediction of CS21 proteins was similar to other well-known type IV pili homologs. We showed that LngP is the prepilin peptidase of LngA, and that ETEC strain E9034A has another peptidase capable of processing LngA, although with less efficiency. Additionally, we present immuno-electron microscopy images to show that the LngB protein could be localized at the tip of CS21. In conclusion, our results demonstrate that the LngA, LngB, LngC, LngD, LngH, and LngP proteins are essential for CS21 assembly, as well as for bacterial aggregation and adherence to HT-29 cells. PMID:27536289

  3. Clinical Implications of Enteroadherent Escherichia coli

    PubMed Central

    Arenas-Hernández, Margarita M.P.; Martínez-Laguna, Ygnacio; Torres, Alfredo G.

    2012-01-01

    Pathogenic Escherichia coli that colonize the small intestine primarily cause gastrointestinal illness in infants and travelers. The main categories of pathogenic E. coli that colonize the epithelial lining of the small intestine are enterotoxigenic E. coli enteropathogenic E. coli and enteroaggregative E. coli. These organisms accomplish their pathogenic process by a complex, coordinated multistage strategy, including non-intimate adherence mediated by various adhesins. These so called “enteroadherent E. coli ” categories subsequently produced toxins or effector proteins that are either secreted to the milieu or injected to the host cell. Finally, destruction of the intestinal microvilli results from the intimate adherence or the toxic effect exerted over the epithelia, resulting in water secretion and diarrhea. In this review, we summarize the current state of knowledge regarding these enteroadherent E. coli strains and the present clinical understanding of how these organisms colonize the human intestine and cause disease. PMID:22798032

  4. Intestinal Colonization by Enterotoxigenic Escherichia coli.

    DTIC Science & Technology

    1980-09-01

    E . coli is mediated by specific types of pili. These pili are antigenic and can be used in diagnosing enterotoxigenic E . coli infections. They are also good protective antigens. When pregnant dams are vaccinated parenterally or orally with pili on live piliated bacteria, they secrete antibodies against the pili in their milk. Neonates suckling dams so vaccinated are passively protected against fatal challenge by enterotoxigenic E . coli . Pili are also good candidate protective antigens for the development of vaccines to protect by

  5. PHYSIOLOGICAL RESPONSES TO LIVE E. COLI ORGANISMS

    DTIC Science & Technology

    shock and shock produced by injection of live E . coli organisms in dogs. A primary purpose of our research has been to determine the effects of...intravenous injections of living E . coli organisms in dogs and monkeys and compare them with responses produced by endotoxin. Hemodynamic changes...pathologic alterations, and metabolic abnormalities have been evaluated in animals receiving lethal and sublethal injections of live E . coli organisms and comparable dosages of purified endotoxin.

  6. Transcription of foreign DNA in Escherichia coli.

    PubMed

    Warren, René L; Freeman, John D; Levesque, Roger C; Smailus, Duane E; Flibotte, Stephane; Holt, Robert A

    2008-11-01

    Propagation of heterologous DNA in E. coli host cells is central to molecular biology. DNA constructs are often engineered for expression of recombinant protein in E. coli, but the extent of incidental transcription arising from natural regulatory sequences in cloned DNA remains underexplored. Here, we have used programmable microarrays and RT-PCR to measure, comprehensively, the transcription of H. influenzae, P. aeruginosa, and human DNA propagating in E. coli as bacterial artificial chromosomes. We find evidence that at least half of all H. influenzae genes are transcribed in E. coli. Highly transcribed genes are principally involved in energy metabolism, and their proximal promoter regions are significantly enriched with E. coli sigma(70) (also known as RpoD) binding sites. H. influenzae genes acquired from an ancient bacteriophage Mu insertion are also highly transcribed. Compared with H. influenzae, a smaller proportion of P. aeruginosa genes are transcribed in E. coli, and in E. coli there is punctuated transcription of human DNA. The presence of foreign DNA in E. coli disturbs the host transcriptional profile, with expression of the E. coli phage shock protein operon and the flagellar gene cluster being particularly strongly up-regulated. While cross-species transcriptional activation is expected to be enabling for horizontal gene transfer in bacteria, incidental expression of toxic genes can be problematic for DNA cloning. Ongoing characterization of cross-expression will help inform the design of biosynthetic gene clusters and synthetic microbial genomes.

  7. Presence of Shiga toxin-producing Escherichia coli, Enteroinvasive E. coli, Enteropathogenic E. coli, and Enterotoxigenic E. coli on tomatoes from public markets in Mexico.

    PubMed

    Gómez-Aldapa, Carlos A; Torres-Vitela, M Del Refugio; Acevedo-Sandoval, Otilio A; Rangel-Vargas, Esmeralda; Villarruel-López, Angélica; Castro-Rosas, Andjavier

    2013-09-01

    Diarrheagenic Escherichia coli pathotypes (DEP) are important foodborne pathogens in various countries, including Mexico. However, no data exist on the presence of DEP on fresh tomatoes (Solanum lycopericum) from Mexico. The frequency of fecal coliforms (FC), E. coli, and DEP were determined for two tomato varieties. One hundred samples of a saladette tomato variety and 100 samples of a red round tomato variety were collected from public markets in Pachuca, Mexico. Each tomato sample consisted of four whole tomatoes. For the 100 saladette samples, coliform bacterial, FC, E. coli, and DEP were identified in 100, 70, 60, and 10% of samples, respectively. For the 100 red round samples, coliform bacterial, FC, E. coli, and DEP were identified in 100, 75, 65, and 11% of samples, respectively. Identified DEP included Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC). STEC were isolated from 6% of saladette samples and 5% of red round samples. ETEC were isolated from 3% of saladette samples and 4% of red round samples. EPEC were isolated from 2% of saladette samples and 3% of red round samples, and EIEC were isolated from 1% of saladette samples. Both STEC and ETEC were identified in two saladette samples and 1 red round sample. E. coli O157:H7 was not detected in any STEC-positive samples.

  8. Susceptibility of porcine intestine to pilus-mediated adhesion by some isolates of piliated enterotoxigenic Escherichia coli increases with age.

    PubMed Central

    Nagy, B; Casey, T A; Whipp, S C; Moon, H W

    1992-01-01

    Two porcine isolates of enterotoxigenic Escherichia coli (ETEC) (serogroup O157 and O141) derived from fatal cases of postweaning diarrhea and lacking K88, K99, F41, and 987P pili (4P- ETEC) were tested for adhesiveness to small-intestinal epithelia of pigs of different ages. Neither strain adhered to isolated intestinal brush borders of newborn (1-day-old) pigs in the presence of mannose. However, mannose-resistant adhesion occurred when brush borders from 10-day- and 3- and 6-week-old pigs were used. Electron microscopy revealed that both strains produced fine (3.5-nm) and type 1 pili at 37 degrees C but only type 1 pili at 18 degrees C. Mannose-resistant in vitro adhesion to brush borders of older pigs correlated with the presence of fine pili. These strains produced predominantly fine pili in ligated intestinal loops of both older and newborn pigs, but adherence was greater in loops in older pigs. Immunoelectron microscopic studies, using antiserum raised against piliated bacteria and absorbed with nonpiliated bacteria, of samples from brush border adherence studies revealed labelled appendages between adherent bacteria and intestinal microvilli. Orogastric inoculation of pigs weaned at 10 and 21 days of age indicated significantly (P less than 0.001) higher levels of adhesion by the ETEC to the ileal epithelia of older pigs than to that of younger ones. We suggest that small-intestinal adhesion and colonization by these ETEC isolates is dependent on receptors that develop progressively with age during the first 3 weeks after birth. Furthermore, our data are consistent with the hypothesis that the fine pili described mediate intestinal adhesion by the 4P- ETEC strains studied. Images PMID:1347758

  9. Susceptibility of porcine intestine to pilus-mediated adhesion by some isolates of piliated enterotoxigenic Escherichia coli increases with age.

    PubMed

    Nagy, B; Casey, T A; Whipp, S C; Moon, H W

    1992-04-01

    Two porcine isolates of enterotoxigenic Escherichia coli (ETEC) (serogroup O157 and O141) derived from fatal cases of postweaning diarrhea and lacking K88, K99, F41, and 987P pili (4P- ETEC) were tested for adhesiveness to small-intestinal epithelia of pigs of different ages. Neither strain adhered to isolated intestinal brush borders of newborn (1-day-old) pigs in the presence of mannose. However, mannose-resistant adhesion occurred when brush borders from 10-day- and 3- and 6-week-old pigs were used. Electron microscopy revealed that both strains produced fine (3.5-nm) and type 1 pili at 37 degrees C but only type 1 pili at 18 degrees C. Mannose-resistant in vitro adhesion to brush borders of older pigs correlated with the presence of fine pili. These strains produced predominantly fine pili in ligated intestinal loops of both older and newborn pigs, but adherence was greater in loops in older pigs. Immunoelectron microscopic studies, using antiserum raised against piliated bacteria and absorbed with nonpiliated bacteria, of samples from brush border adherence studies revealed labelled appendages between adherent bacteria and intestinal microvilli. Orogastric inoculation of pigs weaned at 10 and 21 days of age indicated significantly (P less than 0.001) higher levels of adhesion by the ETEC to the ileal epithelia of older pigs than to that of younger ones. We suggest that small-intestinal adhesion and colonization by these ETEC isolates is dependent on receptors that develop progressively with age during the first 3 weeks after birth. Furthermore, our data are consistent with the hypothesis that the fine pili described mediate intestinal adhesion by the 4P- ETEC strains studied.

  10. Strategies for Protein Overproduction in Escherichia coli.

    ERIC Educational Resources Information Center

    Mott, John E.

    1984-01-01

    Examines heterologous expression in Escherichia coli and the role of regulatory sequences which control gene expression at transcription resulting in abundant production of messenger RNA and regulatory sequences in mRNA which promote efficient translation. Also examines the role of E. coli cells in stabilizing mRNA and protein that is…

  11. Escherichia coli survival in waters: Temperature dependence

    EPA Science Inventory

    Knowing the survival rates of water-borne Escherichia coli is important in evaluating microbial contamination and making appropriate management decisions. E. coli survival rates are dependent on temperature, a dependency that is routinely expressed using an analogue of the Q10 mo...

  12. Third International E. coli genome meeting

    SciTech Connect

    1994-12-31

    Proceedings of the Third E. Coli Genome Meeting are provided. Presentations were divided into sessions entitled (1) Large Scale Sequencing, Sequence Analysis; (2) Databases; (3) Sequence Analysis; (4) Sequence Divergence in E. coli Strains; (5) Repeated Sequences and Regulatory Motifs; (6) Mutations, Rearrangements and Stress Responses; and (7) Origins of New Genes. The document provides a collection of abstracts of oral and poster presentations.

  13. E. coli survival in waters: temperature dependence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowing the survival rates of water-borne Escherichia coli is important for evaluating microbial contamination and in making appropriate management decisions. E. coli survival rates are dependent on temperature; this dependency is routinely expressed using an analog of the Q10 model. This suggestion...

  14. Escherichia coli and Sudden Infant Death Syndrome

    PubMed Central

    Bettelheim, Karl A.; Goldwater, Paul N.

    2015-01-01

    This review examines the association of strains of Escherichia coli with sudden infant death syndrome (SIDS) and the possible role these bacteria play in this enigmatic condition. The review addresses evidence for E. coli in SIDS infants, potential sources of E. coli in the environment, colonization by commensal and pathogenic strains, the variety of currently accepted pathotypes, and how these pathotypes could compromise intestinal integrity and induce inflammation. Both intestinal and extraintestinal pathotypes are compared in relation to the apparent liability in which virulence traits can be gained or lost by strains of E. coli. The way in which E. coli infections fit with current views on infant sleeping position and other SIDS risk factors is highlighted. PMID:26191064

  15. Structure of Escherichia Coli Tryptophanase

    SciTech Connect

    Ku,S.; Yip, P.; Howell, P.

    2006-01-01

    Pyridoxal 5'-phosphate (PLP) dependent tryptophanase has been isolated from Escherichia coli and its crystal structure has been determined. The structure shares the same fold with and has similar quaternary structure to Proteus vulgaris tryptophanase and tyrosine-phenol lyase, but is found in a closed conformation when compared with these two enzymes. The tryptophanase structure, solved in its apo form, does not have covalent PLP bound in the active site, but two sulfate ions. The sulfate ions occupy the phosphoryl-binding site of PLP and the binding site of the {alpha}-carboxyl of the natural substrate tryptophan. One of the sulfate ions makes extensive interactions with both the transferase and PLP-binding domains of the protein and appears to be responsible for holding the enzyme in its closed conformation. Based on the sulfate density and the structure of the P. vulgaris enzyme, PLP and the substrate tryptophan were modeled into the active site. The resulting model is consistent with the roles of Arg419 in orienting the substrate to PLP and acidifying the {alpha}-proton of the substrate for {beta}-elimination, Lys269 in the formation and decomposition of the PLP quinonoid intermediate, Arg230 in orienting the substrate-PLP intermediates in the optimal conformation for catalysis, and His463 and Tyr74 in determining substrate specificity and suggests that the closed conformation observed in the structure could be induced by substrate binding and that significant conformational changes occur during catalysis. A catalytic mechanism for tryptophanase is proposed. Since E. coli tryptophanase has resisted forming diffraction-quality crystals for many years, the molecular surface of tryptophanase has been analyzed in various crystal forms and it was rationalized that strong crystal contacts occur on the flat surface of the protein and that the size of crystal contact surface seems to correlate with the diffraction quality of the crystal.

  16. Structure of Escherichia coli tryptophanase.

    PubMed

    Ku, Shao Yang; Yip, Patrick; Howell, P Lynne

    2006-07-01

    Pyridoxal 5'-phosphate (PLP) dependent tryptophanase has been isolated from Escherichia coli and its crystal structure has been determined. The structure shares the same fold with and has similar quaternary structure to Proteus vulgaris tryptophanase and tyrosine-phenol lyase, but is found in a closed conformation when compared with these two enzymes. The tryptophanase structure, solved in its apo form, does not have covalent PLP bound in the active site, but two sulfate ions. The sulfate ions occupy the phosphoryl-binding site of PLP and the binding site of the alpha-carboxyl of the natural substrate tryptophan. One of the sulfate ions makes extensive interactions with both the transferase and PLP-binding domains of the protein and appears to be responsible for holding the enzyme in its closed conformation. Based on the sulfate density and the structure of the P. vulgaris enzyme, PLP and the substrate tryptophan were modeled into the active site. The resulting model is consistent with the roles of Arg419 in orienting the substrate to PLP and acidifying the alpha-proton of the substrate for beta-elimination, Lys269 in the formation and decomposition of the PLP quinonoid intermediate, Arg230 in orienting the substrate-PLP intermediates in the optimal conformation for catalysis, and His463 and Tyr74 in determining substrate specificity and suggests that the closed conformation observed in the structure could be induced by substrate binding and that significant conformational changes occur during catalysis. A catalytic mechanism for tryptophanase is proposed. Since E. coli tryptophanase has resisted forming diffraction-quality crystals for many years, the molecular surface of tryptophanase has been analyzed in various crystal forms and it was rationalized that strong crystal contacts occur on the flat surface of the protein and that the size of crystal contact surface seems to correlate with the diffraction quality of the crystal.

  17. The evolution of the Escherichia coli phylogeny.

    PubMed

    Chaudhuri, Roy R; Henderson, Ian R

    2012-03-01

    Escherichia coli is familiar to biologists as a classical model system, ubiquitous in molecular biology laboratories around the world. Outside of the laboratory, E. coli strains exist as an almost universal component of the lower-gut flora of humans and animals. Although usually a commensal, E. coli has an alter ego as a pathogen, and is associated with diarrhoeal disease and extra-intestinal infections. The study of E. coli diversity predates the availability of molecular data, with strains initially distinguished by serotyping and metabolic profiling, and genomic diversity illustrated by DNA hybridisation. The quantitative study of E. coli diversity began with the application of multi-locus enzyme electrophoresis (MLEE), and has progressed with the accumulation of nucleotide sequence data, from single genes through multi-locus sequence typing (MLST) to whole genome sequencing. Phylogenetic methods have shed light on the processes of genomic evolution in this extraordinarily diverse species, and revealed the origins of pathogenic E. coli strains, including members of the phylogenetically indistinguishable "genus"Shigella. In May and June 2011, an outbreak of haemorrhagic uraemic syndrome in Germany was linked to a strain of enterohaemorrhagic E. coli (EHEC) O104:H4. Application of high-throughput sequencing technologies allowed the genome and origins of the outbreak strain to be characterised in real time as the outbreak was in progress.

  18. Effect of bile on growth, peritoneal absorption, and blood clearance of Escherichia coli in E coli peritonitis

    SciTech Connect

    Andersson, R.; Schalen, C.; Tranberg, K.G. )

    1991-06-01

    The effect of intraperitoneal bile on growth, peritoneal absorption, and clearance of Escherichia coli was determined in E coli peritonitis in the rat. In E coli peritonitis, intraperitoneal bacterial counts gradually decreased, whereas they increased (after 2 hours) with subsequent development of bacteremia in E coli plus bile peritonitis. After an intraperitoneal injection of labeled bacteria, blood radioactivity was only initially lower in E coli plus bile peritonitis compared with E coli peritonitis. Clearance from blood was lower in E coli plus bile peritonitis than in E coli peritonitis. Organ localization was similar in E coli peritonitis and E coli plus bile peritonitis with decreased splenic, increased pulmonary, and unchanged hepatic uptakes compared with controls. Impaired peritoneal absorption of bacteria, together with impaired local host defense, is likely to enhance the noxious effect of bile in E coli peritonitis.

  19. Low level of cross-resistance between triclosan and antibiotics in Escherichia coli K-12 and E. coli O55 compared to E. coli O157.

    PubMed

    Braoudaki, Maria; Hilton, Anthony Craig

    2004-06-15

    Misuse of biocides has encouraged the emergence of resistance and cross-resistance in certain strains. This study investigated resistance of triclosan-adapted Escherichia coli K-12 and E. coli O55 to antimicrobial agents and compared these to E. coli O157:H7. Cross-resistance in E. coli K-12 and E. coli O55 was observed however to a lesser extent than in E. coli O157:H7. Triclosan-adapted E. coli K-12 demonstrated cross-resistance to chloramphenicol, whereas triclosan-adapted E. coli O55 exhibited resistance to trimethoprim. In comparison, E. coli O157:H7 was resistant to chloramphenicol, tetracycline, amoxicillin, amoxicillin/clavulanic acid, trimethoprim, benzalkonium chloride and chlorohexidine suggesting strain specific rather than general resistance mechanisms.

  20. Advances in genoserotyping and subtyping of Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    E. coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera a...

  1. Survival of pathogenic Escherichia coli on basil, lettuce, and spinach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contamination of lettuce, spinach and basil with pathogenic E. coli has caused numerous illnesses over the past decade. E. coli O157:H7, E. coli O104:H4 and avian pathogenic E. coli (APECstx- and APECstx+) were inoculated on basil plants and in promix soiless substrate using drip and overhead ir...

  2. 21 CFR 866.3255 - Escherichia coli serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Escherichia coli serological reagents. 866.3255... coli serological reagents. (a) Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identify Escherichia coli from...

  3. 21 CFR 866.3255 - Escherichia coli serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Escherichia coli serological reagents. 866.3255... coli serological reagents. (a) Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identify Escherichia coli from...

  4. 21 CFR 866.3255 - Escherichia coli serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Escherichia coli serological reagents. 866.3255... coli serological reagents. (a) Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identify Escherichia coli from...

  5. 21 CFR 866.3255 - Escherichia coli serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Escherichia coli serological reagents. 866.3255... coli serological reagents. (a) Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identify Escherichia coli from...

  6. 21 CFR 866.3255 - Escherichia coli serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Escherichia coli serological reagents. 866.3255... coli serological reagents. (a) Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identify Escherichia coli from...

  7. Electrophoretic Mobilities of Escherichia coli O157:H7 and Wild-Type Escherichia coli Strains

    PubMed Central

    Lytle, Darren A.; Rice, Eugene W.; Johnson, Clifford H.; Fox, Kim R.

    1999-01-01

    The electrophoretic mobilities (EPMs) of a number of Escherichia coli O157:H7 and wild-type E. coli strains were measured. The effects of pH and ionic strength on the EPMs were investigated. The EPMs of E. coli O157:H7 strains differed from those of wild-type strains. As the suspension pH decreased, the EPMs of both types of strains increased. PMID:10388724

  8. Biofuels from E. Coli: Engineering E. coli as an Electrofuels Chassis for Isooctane Production

    SciTech Connect

    2010-07-16

    Electrofuels Project: Ginkgo Bioworks is bypassing photosynthesis and engineering E. coli to directly use carbon dioxide (CO2) to produce biofuels. E. coli doesn’t naturally metabolize CO2, but Ginkgo Bioworks is manipulating and incorporating the genes responsible for CO2 metabolism into the microorganism. By genetically modifying E. coli, Ginkgo Bioworks will enhance its rate of CO2 consumption and liquid fuel production. Ginkgo Bioworks is delivering CO2 to E. coli as formic acid, a simple industrial chemical that provides energy and CO2 to the bacterial system.

  9. First international E. coli genome meeting

    SciTech Connect

    Not Available

    1992-01-01

    This volume is a collection of abstracts of oral presentations and poster sessions of studies reported at the First International E. Coli Genome Meeting, held September 10-14, 1992 at the University of Wisconsin.

  10. First international E. coli genome meeting

    SciTech Connect

    Not Available

    1992-12-31

    This volume is a collection of abstracts of oral presentations and poster sessions of studies reported at the First International E. Coli Genome Meeting, held September 10-14, 1992 at the University of Wisconsin.

  11. Structure of Water in Escherichia Coli B

    DTIC Science & Technology

    structure broadening of the NMR water spectrum. Using bacteria grown in the special chemically defined medium, we showed that the water in E. coli B was highly ordered and was very different from ’free’ water and from polywater .

  12. Native valve Escherichia coli endocarditis following urosepsis.

    PubMed

    Rangarajan, D; Ramakrishnan, S; Patro, K C; Devaraj, S; Krishnamurthy, V; Kothari, Y; Satyaki, N

    2013-05-01

    Gram-negative organisms are a rare cause of infective endocarditis. Escherichia coli, the most common cause of urinary tract infection and gram-negative septicemia involves endocardium rarely. In this case report, we describe infection of native mitral valve by E. coli following septicemia of urinary tract origin in a diabetic male; subsequently, he required prosthetic tissue valve replacement indicated by persistent sepsis and congestive cardiac failure.

  13. Biodegradation of Aromatic Compounds by Escherichia coli

    PubMed Central

    Díaz, Eduardo; Ferrández, Abel; Prieto, María A.; García, José L.

    2001-01-01

    Although Escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. This review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by E. coli. After giving a general overview of the aromatic compounds that E. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on the genes and proteins involved in the catabolism of such compounds, namely, several aromatic acids (phenylacetic acid, 3- and 4-hydroxyphenylacetic acid, phenylpropionic acid, 3-hydroxyphenylpropionic acid, and 3-hydroxycinnamic acid) and amines (phenylethylamine, tyramine, and dopamine). Other enzymatic activities acting on aromatic compounds in E. coli are also reviewed and evaluated. The review also reflects the present impact of genomic research and how the analysis of the whole E. coli genome reveals novel aromatic catabolic functions. Moreover, evolutionary considerations derived from sequence comparisons between the aromatic catabolic clusters of E. coli and homologous clusters from an increasing number of bacteria are also discussed. The recent progress in the understanding of the fundamentals that govern the degradation of aromatic compounds in E. coli makes this bacterium a very useful model system to decipher biochemical, genetic, evolutionary, and ecological aspects of the catabolism of such compounds. In the last part of the review, we discuss strategies and concepts to metabolically engineer E. coli to suit specific needs for biodegradation and biotransformation of aromatics and we provide several examples based on selected studies. Finally, conclusions derived from this review may serve as a lead for future research and applications. PMID:11729263

  14. Biodegradation of aromatic compounds by Escherichia coli.

    PubMed

    Díaz, E; Ferrández, A; Prieto, M A; García, J L

    2001-12-01

    Although Escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. This review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by E. coli. After giving a general overview of the aromatic compounds that E. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on the genes and proteins involved in the catabolism of such compounds, namely, several aromatic acids (phenylacetic acid, 3- and 4-hydroxyphenylacetic acid, phenylpropionic acid, 3-hydroxyphenylpropionic acid, and 3-hydroxycinnamic acid) and amines (phenylethylamine, tyramine, and dopamine). Other enzymatic activities acting on aromatic compounds in E. coli are also reviewed and evaluated. The review also reflects the present impact of genomic research and how the analysis of the whole E. coli genome reveals novel aromatic catabolic functions. Moreover, evolutionary considerations derived from sequence comparisons between the aromatic catabolic clusters of E. coli and homologous clusters from an increasing number of bacteria are also discussed. The recent progress in the understanding of the fundamentals that govern the degradation of aromatic compounds in E. coli makes this bacterium a very useful model system to decipher biochemical, genetic, evolutionary, and ecological aspects of the catabolism of such compounds. In the last part of the review, we discuss strategies and concepts to metabolically engineer E. coli to suit specific needs for biodegradation and biotransformation of aromatics and we provide several examples based on selected studies. Finally, conclusions derived from this review may serve as a lead for future research and applications.

  15. Systems Metabolic Engineering of Escherichia coli.

    PubMed

    Choi, Kyeong Rok; Shin, Jae Ho; Cho, Jae Sung; Yang, Dongsoo; Lee, Sang Yup

    2017-03-01

    Systems metabolic engineering, which recently emerged as metabolic engineering integrated with systems biology, synthetic biology, and evolutionary engineering, allows engineering of microorganisms on a systemic level for the production of valuable chemicals far beyond its native capabilities. Here, we review the strategies for systems metabolic engineering and particularly its applications in Escherichia coli. First, we cover the various tools developed for genetic manipulation in E. coli to increase the production titers of desired chemicals. Next, we detail the strategies for systems metabolic engineering in E. coli, covering the engineering of the native metabolism, the expansion of metabolism with synthetic pathways, and the process engineering aspects undertaken to achieve higher production titers of desired chemicals. Finally, we examine a couple of notable products as case studies produced in E. coli strains developed by systems metabolic engineering. The large portfolio of chemical products successfully produced by engineered E. coli listed here demonstrates the sheer capacity of what can be envisioned and achieved with respect to microbial production of chemicals. Systems metabolic engineering is no longer in its infancy; it is now widely employed and is also positioned to further embrace next-generation interdisciplinary principles and innovation for its upgrade. Systems metabolic engineering will play increasingly important roles in developing industrial strains including E. coli that are capable of efficiently producing natural and nonnatural chemicals and materials from renewable nonfood biomass.

  16. Succinate production in Escherichia coli

    PubMed Central

    Thakker, Chandresh; Martínez, Irene; San, Ka-Yiu; Bennett, George N.

    2012-01-01

    Succinate has been recognized as an important platform chemical that can be produced from biomass. While a number of organisms are capable of succinate production naturally, this review focuses on the engineering of Escherichia coli for production of the four-carbon dicarboxylic acid. Important features of a succinate production system are to achieve optimal balance of reducing equivalents generated by consumption of the feedstock, while maximizing the amount of carbon that is channeled to the product. Aerobic and anaerobic production strains have been developed and applied to production from glucose as well as other abundant carbon sources. Metabolic engineering methods and strain evolution have been used and supplemented by the recent application of systems biology and in silico modeling tools to construct optimal production strains. The metabolic capacity of the production strain, as well as the requirement for efficient recovery of succinate and the reliability of the performance under scale-up are important in the overall process. The costs of the overall biorefinery compatible process will determine the economical commercialization of succinate and its impact in larger chemical markets. PMID:21932253

  17. E. coli on the move

    NASA Astrophysics Data System (ADS)

    Calne, S.

    2012-04-01

    Lynn Grove High School in Great Yarmouth, UK has been awarded a Royal Society partnership grant. Lynn Grove pupils aged between 11 and 16 years will carry out an investigation collaborating with scientists at the John Innes Centre in Norwich, UK to investigate the distribution of E.coli and other coliform bacteria within a school. The information will be used as an evidence base to educate pupils about the transmission of microbes and about methods of control. Through this work pupils will gain an appreciation of the diversity of microbial biochemistry and the chemistry behind chromogenic detection methodologies for specific bacterial enzymes. Inferences from the use of diagnostic selective media will be confirmed by carrying out DNA isolation and PCR to identify the genes responsible for the biochemical reactions. PCR will also be used to identify species of coliforms by reference to genomic sequence databases. These techniques will allow pupils to look into an unseen world in a way which has direct relevance to their everyday lives. Furthermore this partnership study will demonstrate to pupils that solving scientific questions requires the integration of a variety of scientific disciplines. The project will run from January 2012 until June 2012. We will present our preliminary results from the investigation and outline our future plans.

  18. Lytic bacteriophages reduce Escherichia coli O157

    PubMed Central

    Ferguson, Sean; Roberts, Cheryl; Handy, Eric; Sharma, Manan

    2013-01-01

    The role of lytic bacteriophages in preventing cross contamination of produce has not been evaluated. A cocktail of three lytic phages specific for E. coli O157:H7 (EcoShield™) or a control (phosphate buffered saline, PBS) was applied to lettuce by either; (1) immersion of lettuce in 500 ml of EcoShield™ 8.3 log PFU/ml or 9.8 log PFU/ml for up to 2 min before inoculation with E. coli O157:H7; (2) spray-application of EcoShield™ (9.3 log PFU/ml) to lettuce after inoculation with E. coli O157:H7 (4.10 CFU/cm2) following exposure to 50 μg/ml chlorine for 30 sec. After immersion studies, lettuce was spot-inoculated with E. coli O157:H7 (2.38 CFU/cm2). Phage-treated, inoculated lettuce pieces were stored at 4°C for and analyzed for E. coli O157:H7 populations for up to 7 d. Immersion of lettuce in 9.8 log PFU/ml EcoShield™ for 2 min significantly (p < 0.05) reduced E. coli O157:H7 populations after 24 h when stored at 4°C compared with controls. Immersion of lettuce in suspensions containing high concentrations of EcoShield™ (9.8 log PFU/ml) resulted in the deposition of high concentrations (7.8 log log PFU/cm2) of bacteriophages on the surface of fresh cut lettuce, potentially contributing to the efficacy of the lytic phages on lettuce. Spraying phages on to inoculated fresh cut lettuce after being washed in hypochlorite solution was significantly more effective in reducing E. coli O157:H7 populations (2.22 log CFU/cm2) on day 0 compared with control treatments (4.10 log CFU/cm2). Both immersion and spray treatments provided protection from E. coli O157:H7 contamination on lettuce, but spray application of lytic bacteriophages to lettuce was more effective in immediately reducing E. coli O157:H7 populations fresh cut lettuce. PMID:23819106

  19. Transmission OF Campylobacter coli in chicken embryos

    PubMed Central

    Rossi, Daise Aparecida; Fonseca, Belchiolina Beatriz; de Melo, Roberta Torres; Felipe, Gutembergue da Silva; da Silva, Paulo Lourenço; Mendonça, Eliane Pereira; Filgueiras, Ana Luzia Lauria; Beletti, Marcelo Emilio

    2012-01-01

    Campylobacter coli is an important species involved in human cases of enteritis, and chickens are carriers of the pathogen mainly in developing country. The current study aimed to evaluate the transmission of C. coli and its pathogenic effects in chicken embryos. Breeder hens were inoculated intra-esophageally with C. coli isolated from chickens, and their eggs and embryos were analyzed for the presence of bacteria using real-time PCR and plate culture. The viability of embryos was verified. In parallel, SPF eggs were inoculated with C. coli in the air sac; after incubation, the embryos were submitted to the same analysis as the embryos from breeder hens. In embryos and fertile eggs from breeder hens, the bacterium was only identified by molecular methods; in the SPF eggs, however, the bacterium was detected by both techniques. The results showed no relationship between embryo mortality and positivity for C. coli in the embryos from breeder hens. However, the presence of bacteria is a cause of precocious mortality for SPF embryos. This study revealed that although the vertical transmission is a possible event, the bacteria can not grow in embryonic field samples. PMID:24031861

  20. Behavior of non-O157 Shiga toxin-producing Escherichia coli, enteroinvasive E. coli, enteropathogenic E. coli, and enterotoxigenic E. coli strains on alfalfa sprouts.

    PubMed

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Torres-Vitela, M Del Refugio; Villarruel-López, Angélica; Castro-Rosas, Javier

    2013-08-01

    Data about the behavior of non-O157 Shiga toxin-producing Escherichia coli (non-O157 STEC), enteroinvasive E. coli (EIEC), enterotoxigenic E. coli (ETEC), and enteropathogenic E. coli (EPEC) on seeds and alfalfa sprouts are not available. The behavior of STEC, EIEC, ETEC, and EPEC was determined during germination and sprouting of alfalfa seeds at 20 ± 2°C and 30 ± 2°C and on alfalfa sprouts at 3 ± 2°C. When alfalfa seeds were inoculated with STEC, EIEC, ETEC, or EPEC strains, all these diarrheagenic E. coli pathotypes (DEPs) grew during germination and sprouting of seeds, reaching counts of approximately 5 and 6 log CFU/g after 1 day at 20 ± 2°C and 30 ± 2°C, respectively. However, when the sprouts were inoculated after 1 day of seed germination and stored at 20 ± 2°C or 30 ± 2°C, no growth was observed for any DEP during sprouting at 20 ± 2°C or 30 ± 2°C for 9 days. Refrigeration reduced significantly (P < 0.0.5) the number of viable DEPs on sprouts after 20 days in storage; nevertheless, these decreases have no practical significance for the safety of the sprouts.

  1. The 503nm pigment of Escherichia coli

    PubMed Central

    Kamitakahara, Joyce R.; Polglase, W. J.

    1970-01-01

    The yield of cell protein was one-third less for streptomycin-dependent Escherichia coli B than for the wild-type parent strain when both were grown aerobically on a medium with limiting glucose, but anaerobically the yield of protein was similar for both strains. The transient pigment absorbing at 503nm that is known to be present in E. coli and other organisms was not detectable in streptomycin-dependent mutants nor in a non-dependent (energy-deficient) revertant. When wild-type E. coli B was grown on limiting glucose–salts medium containing 2,4 dinitrophenol, the yield of cell protein was decreased and formation of the 503nm pigment was inhibited. Fumarase, aconitase and glucose 6-phosphate dehydrogenase were de-repressed in E. coli B cells grown with excess of glucose in a medium containing 2,4-dinitrophenol. In air-oxidized, wild-type E. coli B cells, the 503nm pigment appeared before reduced cytochromes when gluconate was the substrate but failed to appear when succinate was the substrate. The results provide evidence for a role of the 503nm pigment in aerobic energy metabolism, possibly as an electron acceptor from NADPH. PMID:4395501

  2. Multidrug- and Extensively Drug-Resistant Uropathogenic Escherichia coli Clinical Strains: Phylogenetic Groups Widely Associated with Integrons Maintain High Genetic Diversity

    PubMed Central

    Ochoa, Sara A.; Cruz-Córdova, Ariadnna; Luna-Pineda, Victor M.; Reyes-Grajeda, Juan P.; Cázares-Domínguez, Vicenta; Escalona, Gerardo; Sepúlveda-González, Ma. Eugenia; López-Montiel, Fernanda; Arellano-Galindo, José; López-Martínez, Briceida; Parra-Ortega, Israel; Giono-Cerezo, Silvia; Hernández-Castro, Rigoberto; de la Rosa-Zamboni, Daniela; Xicohtencatl-Cortes, Juan

    2016-01-01

    In recent years, an increase of uropathogenic Escherichia coli (UPEC) strains with Multidrug-resistant (MDR) and Extensively Drug-resistant (XDR) profiles that complicate therapy for urinary tract infections (UTIs) has been observed and has directly impacted costs and extended hospital stays. The aim of this study was to determine MDR- and XDR-UPEC clinical strains, their virulence genes, their phylogenetic groups and to ascertain their relationship with integrons and genetic diversity. From a collection of 500 UPEC strains, 103 were selected with MDR and XDR characteristics. MDR-UPEC strains were mainly associated with phylogenetic groups D (54.87%) and B2 (39.02%) with a high percentage (≥70%) of several fimbrial genes (ecpA, fimH, csgA, and papGII), an iron uptake gene (chuA), and a toxin gene (hlyA). In addition, a moderate frequency (40–70%) of other genes (iutD, tosA, and bcsA) was observed. XDR-UPEC strains were predominantly associated with phylogenetic groups B2 (47.61%) and D (42.85%), which grouped with ≥80 virulence genes, including ecpA, fimH, csgA, papGII, iutD, and chuA. A moderate frequency (40–70%) of the tosA and hlyA genes was observed. The class 1 and 2 integrons that were identified in the MDR- and XDR-UPEC strains were associated with phylogenetic groups D, B2, and A, while the XDR-UPEC strains that were associated with phylogenetic groups B2, D, and A showed an extended-spectrum beta-lactamase (ESBL) phenotype. The modifying enzymes (aadA1, aadB, aacC, ant1, dfrA1, dfrA17, and aadA4) that were identified in the variable region of class 1 and 2 integrons from the MDR strains showed resistance to gentamycin (56.25 and 66.66%, respectively) and trimethoprim-sulfamethoxazole (84.61 and 66.66%, respectively). The MDR- and XDR-UPEC strains were distributed into seven clusters and were closely related to phylogenic groups B2 and D. The diversity analysis by PFGE showed 42.68% of clones of MDR-UPEC and no clonal association in the XDR

  3. Multidrug- and Extensively Drug-Resistant Uropathogenic Escherichia coli Clinical Strains: Phylogenetic Groups Widely Associated with Integrons Maintain High Genetic Diversity.

    PubMed

    Ochoa, Sara A; Cruz-Córdova, Ariadnna; Luna-Pineda, Victor M; Reyes-Grajeda, Juan P; Cázares-Domínguez, Vicenta; Escalona, Gerardo; Sepúlveda-González, Ma Eugenia; López-Montiel, Fernanda; Arellano-Galindo, José; López-Martínez, Briceida; Parra-Ortega, Israel; Giono-Cerezo, Silvia; Hernández-Castro, Rigoberto; de la Rosa-Zamboni, Daniela; Xicohtencatl-Cortes, Juan

    2016-01-01

    In recent years, an increase of uropathogenic Escherichia coli (UPEC) strains with Multidrug-resistant (MDR) and Extensively Drug-resistant (XDR) profiles that complicate therapy for urinary tract infections (UTIs) has been observed and has directly impacted costs and extended hospital stays. The aim of this study was to determine MDR- and XDR-UPEC clinical strains, their virulence genes, their phylogenetic groups and to ascertain their relationship with integrons and genetic diversity. From a collection of 500 UPEC strains, 103 were selected with MDR and XDR characteristics. MDR-UPEC strains were mainly associated with phylogenetic groups D (54.87%) and B2 (39.02%) with a high percentage (≥70%) of several fimbrial genes (ecpA, fimH, csgA, and papGII), an iron uptake gene (chuA), and a toxin gene (hlyA). In addition, a moderate frequency (40-70%) of other genes (iutD, tosA, and bcsA) was observed. XDR-UPEC strains were predominantly associated with phylogenetic groups B2 (47.61%) and D (42.85%), which grouped with ≥80 virulence genes, including ecpA, fimH, csgA, papGII, iutD, and chuA. A moderate frequency (40-70%) of the tosA and hlyA genes was observed. The class 1 and 2 integrons that were identified in the MDR- and XDR-UPEC strains were associated with phylogenetic groups D, B2, and A, while the XDR-UPEC strains that were associated with phylogenetic groups B2, D, and A showed an extended-spectrum beta-lactamase (ESBL) phenotype. The modifying enzymes (aadA1, aadB, aacC, ant1, dfrA1, dfrA17, and aadA4) that were identified in the variable region of class 1 and 2 integrons from the MDR strains showed resistance to gentamycin (56.25 and 66.66%, respectively) and trimethoprim-sulfamethoxazole (84.61 and 66.66%, respectively). The MDR- and XDR-UPEC strains were distributed into seven clusters and were closely related to phylogenic groups B2 and D. The diversity analysis by PFGE showed 42.68% of clones of MDR-UPEC and no clonal association in the XDR

  4. Interaction between Escherichia coli and lunar fines

    NASA Technical Reports Server (NTRS)

    Johansson, K. R.

    1983-01-01

    A sample of mature lunar fines (10084.151) was solubilized to a high degree (about 17 percent) by the chelating agent salicylic acid (0.01. M). The neutralized (pH adjusted to 7.0) leachate was found to inhibit the growth of Escherichia coli (ATCC 259922) in a minimial mineral salts glucose medium; however, the inhibition was somewhat less than that caused by neutralized salicylic acid alone. The presence of lunar fines in the minimal medium was highly stimulatory to growth of E. coli following an early inhibitory response. The bacterium survived less well in the lunar leachate than in distilled water, no doubt because of the salicylate. It was concluded that the sample of lunar soil tested has nutritional value to E. coli and that certain products of fermentation helped to solubilize the lunar soil.

  5. Production of curcuminoids in engineered Escherichia coli.

    PubMed

    Kim, Eun Ji; Cha, Mi Na; Kim, Bog-Gyu; Ahn, Joong-Hoon

    2017-03-09

    Curcumin, a hydrophobic polyphenol derived from the rhizome of the herb Curcuma longa, possesses diverse pharmacological properties including anti-inflammatory, antioxidant, antiproliferative and antiangiogenic activity. Two curcuminoids (dicinnamoylmethane and bisdemethoxycurcumin) were synthesized from glucose in Escherichia coli. PAL (phenylalanine ammonia lyase) or TAL (tyrosine ammonia lyase), along with Os4CL (p-coumaroyl-CoA ligase) and CUS (curcumin synthase), were introduced in to E. coli, and each strain produced dicinnamoylmethane or bisdemethoxycurcumin, respectively. In order to increase the production of curcuminoids in E. coli, the shikimic acid biosynthesis pathway which increases the substrates for curcuminoid biosynthesis, was engineered. Using engineered strains, the production of bisdemethoxycurcumin increased from 0.32 to 4.63 mg/L, and that of dicinnamoylmethane from 1.24 mg/L and 6.95 mg/L.

  6. Frequency-Dependent Escherichia coli Chemotaxis Behavior

    NASA Astrophysics Data System (ADS)

    Zhu, Xuejun; Si, Guangwei; Deng, Nianpei; Ouyang, Qi; Wu, Tailin; He, Zhuoran; Jiang, Lili; Luo, Chunxiong; Tu, Yuhai

    2012-03-01

    We study Escherichia coli chemotaxis behavior in environments with spatially and temporally varying attractant sources by developing a unique microfluidic system. Our measurements reveal a frequency-dependent chemotaxis behavior. At low frequency, the E. coli population oscillates in synchrony with the attractant. In contrast, in fast-changing environments, the population response becomes smaller and out of phase with the attractant waveform. These observations are inconsistent with the well-known Keller-Segel chemotaxis equation. A new continuum model is proposed to describe the population level behavior of E. coli chemotaxis based on the underlying pathway dynamics. With the inclusion of a finite adaptation time and an attractant consumption rate, our model successfully explains the microfluidic experiments at different stimulus frequencies.

  7. Thymineless death in Escherichia coli: strain specificity.

    PubMed

    Cummings, D J; Mondale, L

    1967-06-01

    Thymineless death of various ultraviolet (UV)-sensitive strains of Escherichia coli B and K-12 was investigated. It was found that E. coli B, B(s-12), K-12 rec-21, and possibly K-12 Lon(-), all sensitive to UV, were also sensitive to thymine starvation. However, other UV-sensitive strains of E. coli were found to display the typical resistant-type kinetics of thymineless death. The correlation of these results with various other cellular processes suggested that the filament-forming ability of the bacteria might be involved in the mechanism of thymineless death. It was apparent from the present results that capacity for host-cell reactivation, recombination ability, thymine dimer excision, and probably induction of a defective prophage had little to do with determining sensitivity to thymine deprivation.

  8. Thymineless Death in Escherichia coli: Strain Specificity

    PubMed Central

    Cummings, Donald J.; Mondale, Lee

    1967-01-01

    Thymineless death of various ultraviolet (UV)-sensitive strains of Escherichia coli B and K-12 was investigated. It was found that E. coli B, Bs−12, K-12 rec-21, and possibly K-12 Lon−, all sensitive to UV, were also sensitive to thymine starvation. However, other UV-sensitive strains of E. coli were found to display the typical resistant-type kinetics of thymineless death. The correlation of these results with various other cellular processes suggested that the filament-forming ability of the bacteria might be involved in the mechanism of thymineless death. It was apparent from the present results that capacity for host-cell reactivation, recombination ability, thymine dimer excision, and probably induction of a defective prophage had little to do with determining sensitivity to thymine deprivation. Images PMID:5337772

  9. Diversity of CRISPR loci in Escherichia coli.

    PubMed

    Díez-Villaseñor, C; Almendros, C; García-Martínez, J; Mojica, F J M

    2010-05-01

    CRISPR (clustered regularly interspaced short palindromic repeats) and CAS (CRISPR-associated sequence) proteins are constituents of a novel genetic barrier that limits horizontal gene transfer in prokaryotes by means of an uncharacterized mechanism. The fundamental discovery of small RNAs as the guides of the defence apparatus arose as a result of Escherichia coli studies. However, a survey of the system diversity in this species in order to further contribute to the understanding of the CRISPR mode of action has not yet been performed. Here we describe two CRISPR/CAS systems found in E. coli, following the analysis of 100 strains representative of the species' diversity. Our results substantiate different levels of activity between loci of both CRISPR types, as well as different target preferences and CRISPR relevances for particular groups of strains. Interestingly, the data suggest that the degeneration of one CRISPR/CAS system in E. coli ancestors could have been brought about by self-interference.

  10. Prodigiosin - A Multifaceted Escherichia coli Antimicrobial Agent

    PubMed Central

    Zorec, Maša; Stopar, David

    2016-01-01

    Despite a considerable interest in prodigiosin, the mechanism of its antibacterial activity is still poorly understood. In this work, Escherichia coli cells were treated with prodigiosin to determine its antimicrobial effect on bacterial physiology. The effect of prodigiosin was concentration dependent. In prodigiosin treated cells above MIC value no significant DNA damage or cytoplasmic membrane disintegration was observed. The outer membrane, however, becomes leaky. Cells had severely decreased respiration activity. In prodigiosin treated cells protein and RNA synthesis were inhibited, cells were elongated but could not divide. Pre-treatment with prodigiosin improved E. coli survival rate in media containing ampicillin, kanamycin and erythromycin but not phleomycin. The results suggest that prodigiosin acts as a bacteriostatic agent in E. coli cells. If prodigiosin was diluted, cells resumed growth. The results indicate that prodigiosin has distinct mode of antibacterial action in different bacteria. PMID:27612193

  11. Persistent colonization of sheep by Escherichia coli O157:H7 and other E. coli pathotypes.

    PubMed

    Cornick, N A; Booher, S L; Casey, T A; Moon, H W

    2000-11-01

    Shiga toxin-producing Escherichia coli (STEC) is an important cause of food-borne illness in humans. Ruminants appear to be more frequently colonized by STEC than are other animals, but the reason(s) for this is unknown. We compared the frequency, magnitude, duration, and transmissibility of colonization of sheep by E. coli O157:H7 to that by other pathotypes of E. coli. Young adult sheep were simultaneously inoculated with a cocktail consisting of two strains of E. coli O157:H7, two strains of enterotoxigenic E. coli (ETEC), and one strain of enteropathogenic E. coli. Both STEC strains and ETEC 2041 were given at either 10(7) or 10(10) CFU/strain/animal. The other strains were given only at 10(10) CFU/strain. We found no consistent differences among pathotypes in the frequency, magnitude, and transmissibility of colonization. However, the STEC strains tended to persist to 2 weeks and 2 months postinoculation more frequently than did the other pathotypes. The tendency for persistence of the STEC strains was apparent following an inoculation dose of either 10(7) or 10(10) CFU. One of the ETEC strains also persisted when inoculated at 10(10) CFU. However, in contrast to the STEC strains, it did not persist when inoculated at 10(7) CFU. These results support the hypothesis that STEC is better adapted to persist in the alimentary tracts of sheep than are other pathotypes of E. coli.

  12. Use of specific antibody to demonstrate glycocalyx, K99 pili, and the spatial relationships of K99+ enterotoxigenic Escherichia coli in the ileum of colostrum-fed calves.

    PubMed Central

    Chan, R; Acres, S D; Costerton, J W

    1982-01-01

    The attachment of enterotoxigenic Escherichia coli (ETEC) strain B44 (O9:K30:K99:F41:H-) to the ileal epithelium of newborn colostrum-fed calves was studied by electron microscopy. Stabilization of the bacterial glycocalyx (K30) and pili (K99) by fixation of tissue sections in specific antibody and staining with ruthenium red were used so that the bacterial surface structures could be clearly visualized and their spatial relationship to the intestinal brush border defined. When sections of ileum from infected calves were neither fixed in antibody nor stained with ruthenium red, the ETEC cells colonizing the small intestine were separated from each other and from the brush border by an electron-translucent halo; neither the glycocalyx nor the pili could be clearly resolved. When ruthenium red staining was used, the halo was partially filled by a net of electron-dense fibers composed of pili and condensed glycocalyx which extended to the brush border. Tissue sections reacted with anti-K30 antibody before staining with ruthenium red revealed microcolonies of ETEC surrounded by a discrete electron-dense glycocalyx 0.3 to 1.0 micrometers thick and in tight contact with the epithelial cell surface. When ileal tissue was treated with K99 antibody, the K99 pili were visible as discrete fibers extending from the bacterial cell surface through the glycocalyx. We discuss the role of these cell surface components in pathogenic adhesion and in the formation of protected microcolonies at the surface of the infected ileal epithelium. Images PMID:6127313

  13. Melanosis coli in patients with colon cancer

    PubMed Central

    Biernacka-Wawrzonek, Dorota; Stępka, Michał; Tomaszewska, Alicja; Ehrmann-Jóśko, Agnieszka; Chojnowska, Natalia; Muszyński, Jacek

    2016-01-01

    Introduction Melanosis coli is a benign lesion affecting the mucosa of the large intestine. There is a relationship between the presence of melanosis and anthraquinone laxative use. Melanosis coli is also observed in patients with colon cancer, but there is doubt whether these two conditions are related. Aim To analyze the correlation between melanosis and colon cancer. Material and methods We analyzed retrospectively 436 patients undergoing colon cancer surgery. There were 246 women and 190 men. Patients were divided into three age groups: under 50 years, between 51 and 65 years, and over 66 years. We analyzed sections of the cancer and intestinal mucosa from the tumor’s proximal (2–5 cm) and distal (8–10 cm) zone. Results Melanosis coli was present in 52 patients, which represents 11.9% of patients with colon cancer. More often it was present in women. The most common location of melanosis and colon cancer was the terminal part of the large intestine. In patients below 50 years of age in both sexes melanosis coli did not occur. In men, melanosis was more common in the age group over 66 years. Intensity of pigmentation was higher in the tumor’s distal zone. Conclusions The incidence of melanosis coli increases with age, similar to that of colon cancer. Melanosis was not present inside tumors, in almost half of the cases it was not present in the proximal zone, and the degree of pigmentation increased in distal zone. The cause-effect relationship between melanosis coli and colon cancer remains uncertain. PMID:28337232

  14. Hydrogen production by recombinant Escherichia coli strains

    PubMed Central

    Maeda, Toshinari; Sanchez‐Torres, Viviana; Wood, Thomas K.

    2012-01-01

    Summary The production of hydrogen via microbial biotechnology is an active field of research. Given its ease of manipulation, the best‐studied bacterium Escherichia coli has become a workhorse for enhanced hydrogen production through metabolic engineering, heterologous gene expression, adaptive evolution, and protein engineering. Herein, the utility of E. coli strains to produce hydrogen, via native hydrogenases or heterologous ones, is reviewed. In addition, potential strategies for increasing hydrogen production are outlined and whole‐cell systems and cell‐free systems are compared. PMID:21895995

  15. Uropathogenic Escherichia coli-Associated Exotoxins.

    PubMed

    Welch, Rodney A

    2016-06-01

    Escherichia coli are a common cause of infectious disease outside of the gastrointestinal tract. Several independently evolved E. coli clades are common causes of urinary tract and bloodstream infections. There is ample epidemiological and in vitro evidence that several different protein toxins common to many, but not all, of these strains are likely to aid the colonization and immune-evasion ability of these bacteria. This review discusses our current knowledge and areas of ignorance concerning the contribution of the hemolysin; cytotoxic-necrotizing factor-1; and the autotransporters, Sat, Pic, and Vat, to extraintestinal human disease.

  16. WGS accurately predicts antimicrobial resistance in Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives: To determine the effectiveness of whole-genome sequencing (WGS) in identifying resistance genotypes of multidrug-resistant Escherichia coli (E. coli) and whether these correlate with observed phenotypes. Methods: Seventy-six E. coli strains were isolated from farm cattle and measured f...

  17. Intestinal Colonization by Enterotoxigenic ’Escherichia Coli

    DTIC Science & Technology

    1976-12-01

    Growth of enterotoxigenic E . coli in porcine small intestine selects for piliated forms which adhere to the intestinal epithelium. Surface antigen...K99 on enterotoxigenic E . coli is a pilus. Antigen K99 occurs on porcine enterotoxigenic E . coli strains and is produced in pig small intestine.

  18. 77 FR 9888 - Shiga Toxin-Producing Escherichia coli

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... Food Safety and Inspection Service Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products... manufacturing trimmings for six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups (O26, O45..., non-intact product, that are contaminated with Shiga toxin-producing Escherichia coli (STEC) O26,...

  19. Gentamicin: effect on E. coli in space

    NASA Technical Reports Server (NTRS)

    Kacena, M. A.; Todd, P.

    1999-01-01

    Previous investigations have shown that liquid bacterial cultures grown in space flight were not killed as effectively by antibiotic treatments as were cultures grown on Earth. However, the cause for the decreased antibiotic effectiveness remains unknown. Possible explanations include modified cell proliferation and modified antibiotic transport in the culture medium. Escherichia coli cultures were grown in space flight (STS-69 and STS-73), with and without gentamicin, on a solid agar substrate thus eliminating fluid effects and reducing the unknowns associated with space-flight bacterial cultures in suspension. This research showed that E. coli cultures grown in flight on agar for 24 to 27 hours experienced a heightened growth compared to simultaneous controls. However, addition of gentamicin to the agar killed the bacteria such that both flight and ground control E. coli samples had similar final cell concentrations. Therefore, while the reported existence of a decrease in antibiotic effectiveness in liquid cultures remains unexplained, these data suggest that gentamicin in space flight was at least as effective as, if not more effective than, on Earth, when E. coli cells were grown on agar.

  20. Escherichia coli O157:H7.

    PubMed

    Mead, P S; Griffin, P M

    1998-10-10

    Escherichia coli O157 was first identified as a human pathogen in 1982. One of several Shiga toxin-producing serotypes known to cause human illness, the organism probably evolved through horizontal acquisition of genes for Shiga toxins and other virulence factors. E. coli O157 is found regularly in the faeces of healthy cattle, and is transmitted to humans through contaminated food, water, and direct contact with infected people or animals. Human infection is associated with a wide range of clinical illness, including asymptomatic shedding, non-bloody diarrhoea, haemorrhagic colitis, haemolytic uraemic syndrome, and death. Since laboratory practices vary, physicians need to know whether laboratories in their area routinely test for E. coli O157 in stool specimens. Treatment with antimicrobial agents remains controversial: some studies suggest that treatment may precipitate haemolytic uraemic syndrome, and other studies suggest no effect or even a protective effect. Physicians can help to prevent E. coli O157 infections by counselling patients about the hazards of consuming undercooked ground meat or unpasteurised milk products and juices, and about the importance of handwashing to prevent the spread of diarrhoeal illness, and by informing public-health authorities when they see unusual numbers of cases of bloody diarrhoea or haemolytic uraemic syndrome.

  1. Travelers' diarrhea and toxigenic Escherichia coli.

    PubMed

    Gorbach, S L; Kean, B H; Evans, D G; Evans, D J; Bessudo, D

    1975-05-01

    In a group of 133 United States students studied for 18 days after arriving in Mexico, diarrhea developed in 38 (29 per cent). Diarrhea rarely began before the fourth day, and the mean onset was 13 days after arrival. Symptoms lasted an average of 3.4 days but persisted in 21 per cent of sick students. Heat-labile enterotoxin-producing Escheria coli was found in the stools of 72 per cent of sick and 15 per cent of healthy students. None had heat-labile Esch. coli when they entered Mexico. The incubation period was short, generally 24 to 48 hours, and the carrier state was five days or less in 82 per cent of students surveyed. Entamoeba histolytica was found in 6 per cent of cases of diarrhea, but not salmonella, shigella or penetrating Esch. coli. These studies suggest that approximately 70 per cent of travelers' diarrhea in Mexico is associated with heat-labile toxigenic strains of Esch. coli.

  2. E. Coli: Preventing Outbreaks at Camp.

    ERIC Educational Resources Information Center

    McKinney, Mary D.

    1996-01-01

    One strain of E. coli is not usually found in foods, but has been related to consumption of undercooked ground beef. Symptoms are stomach cramps and diarrhea, and 2-7% of infections lead to hemolytic uremic syndrome, which is life threatening. Camps can prevent outbreaks by avoiding uncooked meat on overnight campouts and requiring appropriate…

  3. Hybrid speciation in agricultural Campylobacter coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction Hybridization between distantly related organisms can facilitate rapid adaptation but is constrained by epistatic fitness interactions. The zoonotic pathogens Campylobacter coli and C. jejuni differ from each other at an average of nearly 40 amino acids per gene. Nevertheless, they have...

  4. Transport proteins promoting Escherichia coli pathogenesis.

    PubMed

    Tang, Fengyi; Saier, Milton H

    2014-01-01

    Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies.

  5. Transport proteins promoting Escherichia coli pathogenesis

    PubMed Central

    Tang, Fengyi; Saier, Milton H.

    2014-01-01

    Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. PMID:24747185

  6. Extracellular recombinant protein production from Escherichia coli.

    PubMed

    Ni, Ye; Chen, Rachel

    2009-11-01

    Escherichia coli is the most commonly used host for recombinant protein production and metabolic engineering. Extracellular production of enzymes and proteins is advantageous as it could greatly reduce the complexity of a bioprocess and improve product quality. Extracellular production of proteins is necessary for metabolic engineering applications in which substrates are polymers such as lignocelluloses or xenobiotics since adequate uptake of these substrates is often an issue. The dogma that E. coli secretes no protein has been challenged by the recognition of both its natural ability to secrete protein in common laboratory strains and increased ability to secrete proteins in engineered cells. The very existence of this review dedicated to extracellular production is a testimony for outstanding achievements made collectively by the community in this regard. Four strategies have emerged to engineer E. coli cells to secrete recombinant proteins. In some cases, impressive secretion levels, several grams per liter, were reached. This secretion level is on par with other eukaryotic expression systems. Amid the optimism, it is important to recognize that significant challenges remain, especially when considering the success cannot be predicted a priori and involves much trials and errors. This review provides an overview of recent developments in engineering E. coli for extracellular production of recombinant proteins and an analysis of pros and cons of each strategy.

  7. Engineering Escherichia coli for methanol conversion.

    PubMed

    Müller, Jonas E N; Meyer, Fabian; Litsanov, Boris; Kiefer, Patrick; Potthoff, Eva; Heux, Stéphanie; Quax, Wim J; Wendisch, Volker F; Brautaset, Trygve; Portais, Jean-Charles; Vorholt, Julia A

    2015-03-01

    Methylotrophic bacteria utilize methanol and other reduced one-carbon compounds as their sole source of carbon and energy. For this purpose, these bacteria evolved a number of specialized enzymes and pathways. Here, we used a synthetic biology approach to select and introduce a set of "methylotrophy genes" into Escherichia coli based on in silico considerations and flux balance analysis to enable methanol dissimilation and assimilation. We determined that the most promising approach allowing the utilization of methanol was the implementation of NAD-dependent methanol dehydrogenase and the establishment of the ribulose monophosphate cycle by expressing the genes for hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi). To test for the best-performing enzymes in the heterologous host, a number of enzyme candidates from different donor organisms were selected and systematically analyzed for their in vitro and in vivo activities in E. coli. Among these, Mdh2, Hps and Phi originating from Bacillus methanolicus were found to be the most effective. Labeling experiments using (13)C methanol with E. coli producing these enzymes showed up to 40% incorporation of methanol into central metabolites. The presence of the endogenous glutathione-dependent formaldehyde oxidation pathway of E. coli did not adversely affect the methanol conversion rate. Taken together, the results of this study represent a major advancement towards establishing synthetic methylotrophs by gene transfer.

  8. Escherichia Coli--Key to Modern Genetics.

    ERIC Educational Resources Information Center

    Bregegere, Francois

    1982-01-01

    Mid-nineteenth century work by Mendel on plant hybrids and by Pasteur on fermentation gave birth by way of bacterial genetics to modern-day molecular biology. The bacterium Escherichia Coli has occupied a key position in genetic studies leading from early gene identification with DNA to current genetic engineering using recombinant DNA technology.…

  9. Quantitative Proteomics of the E. coli Membranome.

    PubMed

    Tsolis, K C; Economou, A

    2017-01-01

    Due to their physicochemical properties, membrane protein proteomics analyses often require extensive sample preparation protocols resulting in sample loss and introducing technical variation. Several methods for membrane proteomics have been described, designed to meet the needs of specific sample types and experimental designs. Here, we present a complete membrane proteomics pipeline starting from the membrane sample preparation to the protein identification/quantification and also discuss about annotation of proteomics data. The protocol has been developed using Escherichia coli samples but is directly adaptable to other bacteria including pathogens. We describe a method for the preparation of E. coli inner membrane vesicles (IMVs) central to our pipeline. IMVs are functional membrane vesicles that can also be used for biochemical studies. Next, we propose methods for membrane protein digestion and describe alternative experimental approaches that have been previously tested in our lab. We highlight a surface proteolysis protocol for the identification of inner membrane and membrane-bound proteins. This is a simple, fast, and reproducible method for the membrane sample characterization that has been previously used for the E. coli inner membrane proteome characterization (Papanastasiou et al., 2013) and the experimental validation of E. coli membrane proteome (Orfanoudaki & Economou, 2014). It provides a reduced load on MS-time and allows for multiple repeats. Then we discuss membrane protein quantification approaches and tools that can be used for the functional annotation of identified proteins. Overall, membrane proteome quantification can be fast, simplified, and reproducible; however, optimization steps should be performed for a given sample type.

  10. Ethanol production using engineered mutant E. coli

    DOEpatents

    Ingram, Lonnie O.; Clark, David P.

    1991-01-01

    The subject invention concerns novel means and materials for producing ethanol as a fermentation product. Mutant E. coli are transformed with a gene coding for pyruvate decarboxylase activity. The resulting system is capable of producing relatively large amounts of ethanol from a variety of biomass sources.

  11. Engineering Escherichia coli to bind to cyanobacteria.

    PubMed

    Zhang, Zijian; Meng, Liuyi; Ni, Congjian; Yao, Lanqiu; Zhang, Fengyu; Jin, Yuji; Mu, Xuelang; Zhu, Shiyu; Lu, Xiaoyu; Liu, Shiyu; Yu, Congyu; Wang, Chenggong; Zheng, Pu; Wu, Jie; Kang, Li; Zhang, Haoqian M; Ouyang, Qi

    2017-03-01

    We engineered Escherichia coli cells to bind to cyanobacteria by heterologously producing and displaying lectins of the target cyanobacteria on their surface. To prove the efficacy of our approach, we tested this design on Microcystis aeruginosa with microvirin (Mvn), the lectin endogenously produced by this cyanobacterium. The coding sequence of Mvn was C-terminally fused to the ice nucleation protein NC (INPNC) gene and expressed in E. coli. Results showed that E. coli cells expressing the INPNC::Mvn fusion protein were able to bind to M. aeruginosa and the average number of E. coli cells bound to each cyanobacterial cell was enhanced 8-fold. Finally, a computational model was developed to simulate the binding reaction and help reconstruct the binding parameters. To our best knowledge, this is the first report on the binding of two organisms in liquid culture mediated by the surface display of lectins and it may serve as a novel approach to mediate microbial adhesion.

  12. Impact of dry chilling on the genetic diversity of Escherichia coli on beef carcasses and on the survival of E. coli and E. coli O157.

    PubMed

    Visvalingam, Jeyachchandran; Liu, Yang; Yang, Xianqin

    2017-03-06

    The objective of this study was to examine the effect of dry chilling on the genetic diversity of naturally occurring Escherichia coli on beef carcasses, and to examine whether two populations of E. coli recovered from carcasses during chilling and E. coli O157 differed in their response to desiccation. Isolates of E. coli were obtained from beef carcasses during a 67h dry chilling process and were genotyped using multiple-locus variable-number tandem-repeat analysis (MLVA). Ten E. coli genotypes found only at 0h (group A) and found more than once (group B), as well as five strains of E. coli O157 (group C) were inoculated on stainless steel coupons and their survival was examined after exposure to 75 and 100% relative humidity (RH) at 0 or 35°C for 67h. A total of 450 E. coli isolates were obtained, with 254, 49, 49, 51, 23, 20, and 4 from 0, 1, 2, 4, 6, 8 and 24h of chilling, respectively. No E. coli were recovered at 67h. MLVA of the isolates revealed 173 distinct genotypes. Genetic diversity of E. coli isolates, defined as ratio of the number of isolates to the number of genotypes, remained between 2.3 and 1.3 during the 24h of chilling. All strains inoculated on stainless steel coupons and exposed to 75% RH at 35°C were completely inactivated, irrespective of their groups. Inactivation of E. coli of the three groups was not significantly (P>0.05) different by exposure to 75% RH at 0°C. The findings indicate that the genetic diversity of E. coli on beef carcasses was not affected by dry chilling. In addition, inactivation of E. coli genotypes and E. coli O157 by desiccation on stainless steel simulating dry chilling conditions did not differ significantly (P>0.05). Thus, dry chilling may be used as an effective antimicrobial intervention for beef carcasses.

  13. Genotypic Characterization of Egypt Enterotoxigenic Escherichia coli Isolates Expressing Coli Surface Antigen 6

    DTIC Science & Technology

    2013-02-01

    USA Abstract Introduction: One approach to control enterotoxigenic Escherichia coli (ETEC) infections has been to develop vaccines focused on...results show a lack of clonality among Egypt CS6 E. coli isolates and supports the use and the further research on vaccines targeting this cell surface...has received considerable attention as a target for vaccine development [11-14]. CS6 is immunogenic in humans both after natural infection and

  14. CRISPRi engineering E. coli for morphology diversification.

    PubMed

    Elhadi, Dina; Lv, Li; Jiang, Xiao-Ran; Wu, Hong; Chen, Guo-Qiang

    2016-11-01

    Microbial morphology engineering has recently become interesting for biotechnology. Genes ftsZ and mreB encoding proteins of bacterial fission ring and skeletons, respectively, are essential for cell growth, they both are the most important genes keeping the bacterial shapes including the cell length and width, respectively. Clustered regularly interspaced short palindromic repeats interference, abbreviated as CRISPRi, was for the first time used in this study to regulate expression intensities of ftsZ or/and mreB in E. coli. Five sgRNAs associated with CRISPRi were designed and synthesized, respectively, to target five various locations on genes ftsZ or mreB encoded in the E. coli chromosome, resulting in various reduced expression levels of ftsZ or/and mreB, respectively, forming elongated or/and fatter cells. Repressions on gene expressions of ftsZ or/and mreB could be further intensified by combining various sgRNAs together. It was found that the stronger the repression on genes ftsZ or/and mreB, the longer the E. coli fibers, and the larger the E. coli cells. Combined repressions on expressions of ftsZ and mreB generated long and larger E. coli with diverse morphologies including various sizes of gourds, bars, coccus, spindles, multi-angles and ellipsoids. In all cases, accumulations of intracellular biopolyester polyhydroxybutyrate (PHB) were in direct proportional to the intracellular volumes, ranging from 40% to 80% PHB in bacterial cell dry weights, depending on the cell volumes increases by the above CRISPRi applications.

  15. Diarrhea, bacteremia and multiorgan dysfunction due to an extraintestinal pathogenic Escherichia coli strain with enteropathogenic E. coli genes.

    PubMed

    Kessler, Robert; Nisa, Shahista; Hazen, Tracy H; Horneman, Amy; Amoroso, Anthony; Rasko, David A; Donnenberg, Michael S

    2015-11-01

    A 55-year-old man with well-controlled HIV had severe diarrhea for 3 weeks and developed multiorgan dysfunction and bacteremia due to Escherichia coli. The genome of the patient's isolate had features characteristic of extraintestinal pathogenic E. coli and genes distantly related to those defining enteropathogenic E. coli.

  16. Fimbrial-mediated colonization of murine teeth by Actinomyces naeslundii.

    PubMed

    Beem, J E; Hurley, C G; Nesbitt, W E; Croft, D F; Marks, R G; Cisar, J O; Clark, W B

    1996-08-01

    Groups of mice fed diets high in sucrose or glucose were orally inoculated with 10(10), 10(9) or 10(8) colony-forming units of one of the following Actinomyces naeslundii strains possessing the type 1 (T1+) and/or the type 2 (T2+) fimbriae: T14VJ1 (T1+, T2+), 5519 (T1+), 5951 (T2+), and 147 (non-fimbriated). Ninety-six hours after inoculation their upper jaws were cultured to look at the implantation of each of these strains on the teeth. In mice fed a sucrose diet, regardless of the presence or absence of fimbriae, each bacterial strain colonized 100% of the mice at the highest inoculation doses of the infecting organism. But at a dose of 10(8), T14V-J1 was the only strain which colonized 100% (12/12) of the mice, 5519 colonized 10/11, 5951 colonized 9/11 and 147 colonized 7/11. These differences were not statistically significant. When mice were fed a high-glucose diet, 100% infection was achieved with strains T14V-J1, 5519 and 5951 only at the highest dose of 10(10) colony-forming units. Strain 147 colonized in 8/9 of the mice at that dosage. At lower dosages, no bacterial strain implanted in 100% of the mice. In the glucose experiment at a dose of 10(8), strains expressing the T1 fimbriae implanted significantly better than strains without the T1 fimbriae. At a dose of 10(9) colony-forming units, the parent strain T14V-J1 implanted significantly better than strains without the T1 fimbriae. Similarly, strain 5519 (T1+) implanted significantly better than 5951 and implanted better than 147, although the difference was not significant. These results suggest that while the presence of the T1 and T2 fimbriae may confer some advantage in the establishment of these organisms in vivo, even the strains without fimbriae were able to colonize. Strains T14VJ1 and 5519 were found to bind well to hydroxyapatite treated with mouse saliva, while strains 5951 and 147 did not. Only T2 fimbriated strains T14V-J1 and 5951 exhibited a lactose-reversible coaggreation with indigenous strains of enterococci that may contribute to the elevated levels of colonization of strain 5951 in vivo.

  17. Sources of Escherichia coli in a Coastal Subtropical Environment

    PubMed Central

    Solo-Gabriele, Helena M.; Wolfert, Melinda A.; Desmarais, Timothy R.; Palmer, Carol J.

    2000-01-01

    Sources of Escherichia coli in a coastal waterway located in Ft. Lauderdale, Fla., were evaluated. The study consisted of an extensive program of field measurements designed to capture spatial and temporal variations in E. coli concentrations as well as experiments conducted under laboratory-controlled conditions. E. coli from environmental samples was enumerated by using a defined substrate technology (Colilert-18). Field sampling tasks included sampling the length of the North Fork to identify the river reach contributing high E. coli levels, autosampler experiments at two locations, and spatially intense sampling efforts at hot spots. Laboratory experiments were designed to simulate tidal conditions within the riverbank soils. The results showed that E. coli entered the river in a large pulse during storm conditions. After the storm, E. coli levels returned to baseline levels and varied in a cyclical pattern which correlated with tidal cycles. The highest concentrations were observed during high tide, whereas the lowest were observed at low tide. This peculiar pattern of E. coli concentrations between storm events was caused by the growth of E. coli within riverbank soils which were subsequently washed in during high tide. Laboratory analysis of soil collected from the riverbanks showed increases of several orders of magnitude in soil E. coli concentrations. The ability of E. coli to multiply in the soil was found to be a function of soil moisture content, presumably due to the ability of E. coli to outcompete predators in relatively dry soil. The importance of soil moisture in regulating the multiplication of E. coli was found to be critical in tidally influenced areas due to periodic wetting and drying of soils in contact with water bodies. Given the potential for growth in such systems, E. coli concentrations can be artificially elevated above that expected from fecal impacts alone. Such results challenge the use of E. coli as a suitable indicator of water

  18. Uropathogenic Escherichia coli are less likely than paired fecal E. coli to have CRISPR loci.

    PubMed

    Dang, Trang Nguyen Doan; Zhang, Lixin; Zöllner, Sebastian; Srinivasan, Usha; Abbas, Khadija; Marrs, Carl F; Foxman, Betsy

    2013-10-01

    CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats) are short fragments of DNA that act as an adaptive immune system protecting bacteria against invasion by phages, plasmids or other forms of foreign DNA. Bacteria without a CRISPR locus may more readily adapt to environmental changes by acquiring foreign genetic material. Uropathogenic Escherichia coli (UPEC) live in a number of environments suggesting an ability to rapidly adapt to new environments. If UPEC are more adaptive than commensal E. coli we would expect that UPEC would have fewer CRISPR loci, and--if loci are present--that they would harbor fewer spacers than CRISPR loci in fecal E. coli. We tested this in vivo by comparing the number of CRISPR loci and spacers, and sensitivity to antibiotics (resistance is often obtained via plasmids) among 81 pairs of UPEC and fecal E. coli isolated from women with urinary tract infection. Each pair included one uropathogen and one commensal (fecal) sample from the same female patient. Fecal isolates had more repeats (p=0.009) and more unique spacers (p<0.0001) at four CRISPR loci than uropathogens. By contrast, uropathogens were more likely than fecal E. coli to be resistant to ampicillin, cefazolin and trimethoprim/sulfamethoxazole. However, no consistent association between CRISPRs and antibiotic resistance was identified. To our knowledge, this is the first study to compare fecal E. coli and pathogenic E. coli from the same individuals, and to test the association of CRISPR loci with antibiotic resistance. Our results suggest that the absence of CRISPR loci may make UPEC more susceptible to infection by phages or plasmids and allow them to adapt more quickly to various environments.

  19. Leukemia and risk of recurrent Escherichia coli bacteremia: genotyping implicates E. coli translocation from the colon to the bloodstream.

    PubMed

    Samet, A; Sledzińska, A; Krawczyk, B; Hellmann, A; Nowicki, S; Kur, J; Nowicki, B

    2013-11-01

    In patients with leukemia, the portal(s) and reasons for the persistence of an Escherichia coli recurrent bacteremia remain unclear. Adult Hematology Clinic (AHC) databases at the State Clinical Hospital in Gdańsk were reviewed to evaluate the frequency of E. coli bacteremia between 2002 and 2005. Blood and bowel E. coli strains were obtained and the genetic relatedness of the strains was analyzed. The rate of E. coli bacteremia per 1,000 admissions at the AHC was higher (85.0) than in the other clinics of the hospital (2.9), p < 0.001. A higher mortality was observed in patients with a history of E. coli versus non-E. coli bacteremia [30/95 (31 %) vs. 53/430 (12 %), p < 0.001]; 72.8 % of patients with leukemia had an unknown source of bacteremia. In 2005, 6 out of 25 (24 %) patients with leukemia had ≥2 episodes of E. coli-positive blood cultures. These gastrointestinal E. coli isolates were replaced within 3-8 weeks with a new E. coli H genotype. A recurrent episode of bacteremia was usually caused by an infection with a transient E. coli H genotype identical to that found in the subject's bowel. Consistent with the definition of bowel/blood translocation, the bowel appeared to be a portal for E. coli in these subjects and, hence, a clear source for their recurring bacteremia.

  20. [Escherichia coli R live vaccine Suicolplex "Dessau"].

    PubMed

    Michael-Meese, M; Klie, H; Schöll, W

    1980-01-01

    Immunisation of pregnant sows prior to parturition has long proved to be a good method to forestall coli dysentery in piglets before weaning. Inactivated vaccines of the pathogenetically important E. coli serogroups with and without adjuvant so far were primarily used at international level. A vaccine of that kind has become available in the GDR more than eight years ago. Its name is Coliporc "Dessau". A live vaccine has been developed from two R-mutants at the authors' institute. The effectiveness of that live vaccine on laboratory animals and in field experiments is reported in this paper together with possibilities of differential diagnosis to distinguish wild strains from the mutants. The live vaccine was commercially registered under the name of Suicolpex "Dessau", in spring 1976.

  1. Designed phosphoprotein recognition in Escherichia coli.

    PubMed

    Sawyer, Nicholas; Gassaway, Brandon M; Haimovich, Adrian D; Isaacs, Farren J; Rinehart, Jesse; Regan, Lynne

    2014-11-21

    Protein phosphorylation is a central biological mechanism for cellular adaptation to environmental changes. Dysregulation of phosphorylation signaling is implicated in a wide variety of diseases. Thus, the ability to detect and quantify protein phosphorylation is highly desirable for both diagnostic and research applications. Here we present a general strategy for detecting phosphopeptide-protein interactions in Escherichia coli. We first redesign a model tetratricopeptide repeat (TPR) protein to recognize phosphoserine in a sequence-specific fashion and characterize the interaction with its target phosphopeptide in vitro. We then combine in vivo site-specific incorporation of phosphoserine with split mCherry assembly to observe the designed phosphopeptide-protein interaction specificity in E. coli. This in vivo strategy for detecting and characterizing phosphopeptide-protein interactions has numerous potential applications for the study of natural interactions and the design of novel ones.

  2. Automatic tracking of Escherichia coli bacteria.

    PubMed

    Xie, Jun; Khan, Shahid; Shah, Mubarak

    2008-01-01

    In this paper, we present an automatic method for estimating the trajectories of Escherichia coli bacteria from in vivo phase-contrast microscopy videos. To address the low-contrast boundaries in cellular images, an adaptive kernel-based technique is applied to detect cells in sequence of frames. Then a novel matching gain measure is introduced to cope with the challenges such as dramatic changes of cells' appearance and serious overlapping and occlusion. For multiple cell tracking, an optimal matching strategy is proposed to improve the handling of cell collision and broken trajectories. The results of successful tracking of Escherichia coli from various phase-contrast sequences are reported and compared with manually-determined trajectories, as well as those obtained from existing tracking methods. The stability of the algorithm with different parameter values is also analyzed and discussed.

  3. Escherichia coli growth under modeled reduced gravity

    NASA Technical Reports Server (NTRS)

    Baker, Paul W.; Meyer, Michelle L.; Leff, Laura G.

    2004-01-01

    Bacteria exhibit varying responses to modeled reduced gravity that can be simulated by clino-rotation. When Escherichia coli was subjected to different rotation speeds during clino-rotation, significant differences between modeled reduced gravity and normal gravity controls were observed only at higher speeds (30-50 rpm). There was no apparent affect of removing samples on the results obtained. When E. coli was grown in minimal medium (at 40 rpm), cell size was not affected by modeled reduced gravity and there were few differences in cell numbers. However, in higher nutrient conditions (i.e., dilute nutrient broth), total cell numbers were higher and cells were smaller under reduced gravity compared to normal gravity controls. Overall, the responses to modeled reduced gravity varied with nutrient conditions; larger surface to volume ratios may help compensate for the zone of nutrient depletion around the cells under modeled reduced gravity.

  4. Detection of Escherichia coli enterotoxins in stools.

    PubMed Central

    Merson, M H; Yolken, R H; Sack, R B; Froehlich, J L; Greenberg, H B; Huq, I; Black, R W

    1980-01-01

    We determined whether enterotoxigenic Escherichia coli diarrhea could be diagnosed by direct examination of stools for heat-labile (LT) and heat-stable (ST) enterotoxins. The Y-1 adrenal cell and an enzyme-linked immunosorbent assay (ELISA) detected LT in 85 and 93%, respectively, of stool specimens obtained from adults with acute diarrhea from whom an LT- and ST-producing organism had been isolated. Furthermore, the ELISA assay detected LT in 8 of 35 stool specimens from which no LT-producing E. coli had been isolated. The infant mouse assay was utilized to detect ST in these stool specimens and was found to be an insensitive method, showing positive results in only 36% of the specimens from which an ST-producing organism was isolated. Further studies are warranted to determine the diagnostic value of direct detection of LT in stools, especially by the ELISA method. PMID:6995331

  5. Compilation of DNA sequences of Escherichia coli

    PubMed Central

    Kröger, Manfred

    1989-01-01

    We have compiled the DNA sequence data for E.coli K12 available from the GENBANK and EMBO databases and over a period of several years independently from the literature. We have introduced all available genetic map data and have arranged the sequences accordingly. As far as possible the overlaps are deleted and a total of 940,449 individual bp is found to be determined till the beginning of 1989. This corresponds to a total of 19.92% of the entire E.coli chromosome consisting of about 4,720 kbp. This number may actually be higher by some extra 2% derived from the sequence of lysogenic bacteriophage lambda and the various insertion sequences. This compilation may be available in machine readable form from one of the international databanks in some future. PMID:2654890

  6. Silver nanoparticle-E. coli colloidal interaction in water and effect on E. coli survival.

    PubMed

    Dror-Ehre, A; Mamane, H; Belenkova, T; Markovich, G; Adin, A

    2009-11-15

    Silver nanoparticles exhibit antibacterial properties via bacterial inactivation and growth inhibition. The mechanism is not yet completely understood. This work was aimed at elucidating the effect of silver nanoparticles on inactivation of Escherichia coli, by studying particle-particle interactions in aqueous suspensions. Stable, molecularly capped, positively or negatively charged silver nanoparticles were mixed at 1 to 60microgmL(-1) with suspended E. coli cells to examine their effect on inactivation of the bacteria. Gold nanoparticles with the same surfactant were used as a control, being of similar size but made up of a presumably inert metal. Log reduction of 5log(10) and complete inactivation were obtained with the silver nanoparticles while the gold nanoparticles did not show any inactivation ability. The effect of molecularly capped nanoparticles on E. coli survival was dependent on particle number. Log reduction of E. coli was associated with the ratio between the number of nanoparticles and the initial bacterial cell count. Electrostatic attraction or repulsion mechanisms in silver nanoparticle-E. coli cell interactions did not contribute to the inactivation process.

  7. Secretion of clostridium cellulase by E. coli

    DOEpatents

    Yu, Ida Kuo

    1998-01-01

    A gene, encoding an endocellulase from a newly isolated mesophilic Clostridium strain IY-2 which can digest bamboo fibers, cellulose, rice straw, and sawdust, was isolated by shotgun cloning in an E. coli expression plasmid pLC2833. E. coli positive clones were selected based on their ability to hydrolyze milled bamboo fibers and cellulose present in agar plates. One clone contained a 2.8 kb DNA fragment that was responsible for cellulase activity. Western blot analyses indicated that the positive clone produced a secreted cellulase with a mass of about 58,000 daltons that was identical in size to the subunit of one of the three major Clostridium cellulases. The products of cellulose digestion by this cloned cellulase were cellotetraose and soluble higher polymers. The cloned DNA contained signal sequences capable of directing the secretion of heterologous proteins from an E. coli host. The invention describes a bioprocess for the treatment of cellulosic plant materials to produce cellular growth substrates and fermentation end products suitable for production of liquid fuels, solvents, and acids.

  8. Arabidopsis alternative oxidase sustains Escherichia coli respiration.

    PubMed Central

    Kumar, A M; Söll, D

    1992-01-01

    Glutamyl-tRNA reductase, encoded by the hemA gene, is the first enzyme in porphyrin biosynthesis in many organisms. Hemes, important porphyrin derivatives, are essential components of redox enzymes, such as cytochromes. Thus a hemA Escherichia coli strain (SASX41B) is deficient in cytochrome-mediated aerobic respiration. Upon complementation of this strain with an Arabidopsis thaliana cDNA library, we isolated a clone which permitted the SASX41B strain to grow aerobically. The clone encodes the gene for Arabidopsis alternative oxidase, whose deduced amino acid sequence was found to have 71% identity with that of the enzyme from the voodoo lily, Sauromatum guttatum. The Arabidopsis protein is expressed as a 31-kDa protein in E. coli and confers on this organism cyanide-resistant growth, which in turn is sensitive to salicylhydroxamate. This implies that a single polypeptide is sufficient for alternative oxidase activity. Based on these observations we propose that a cyanide-insensitive respiratory pathway operates in the transformed E. coli hemA strain. Introduction of this pathway now opens the way to genetic/molecular biological investigations of alternative oxidase and its cofactor. Images PMID:1438286

  9. Role of Escherichia coli in Biofuel Production

    PubMed Central

    Koppolu, Veerendra; Vasigala, Veneela KR

    2016-01-01

    Increased energy consumption coupled with depleting petroleum reserves and increased greenhouse gas emissions have renewed our interest in generating fuels from renewable energy sources via microbial fermentation. Central to this problem is the choice of microorganism that catalyzes the production of fuels at high volumetric productivity and yield from cheap and abundantly available renewable energy sources. Microorganisms that are metabolically engineered to redirect renewable carbon sources into desired fuel products are contemplated as best choices to obtain high volumetric productivity and yield. Considering the availability of vast knowledge in genomic and metabolic fronts, Escherichia coli is regarded as a primary choice for the production of biofuels. Here, we reviewed the microbial production of liquid biofuels that have the potential to be used either alone or in combination with the present-day fuels. We specifically highlighted the metabolic engineering and synthetic biology approaches used to improve the production of biofuels from E. coli over the past few years. We also discussed the challenges that still exist for the biofuel production from E. coli and their possible solutions. PMID:27441002

  10. Regulation of alcohol fermentation by Escherichia coli

    SciTech Connect

    Clark, D.P.

    1989-01-01

    The purpose of this project is to elucidate the way in which the fermentative synthesis of ethanol is regulated in the facultative anaerobe Escherichia coli. We are also investigating the control of other genes required for fermentation and anaerobic growth. We have isolated both structural and regulatory mutations affecting the expression of alcohol dehydrogenase, the enzyme responsible for the final step in alcohol synthesis. Some of these regulatory mutations also affect other anaerobically induced genes. The adh gene has been cloned and sequenced. The ADH protein is one of the largest highly expressed proteins in E. coli and requires approximately 2700bp of DNA for its cloning sequence. We have also isolated mutations affecting the fermentative lactate dehydrogenase. In consequence it is now possible to construct E. coli strains defective in the production of any one or more of their normal fermentation products (i.e. formate, acetate, lactate, ethanol and succinate). The factors affecting the ratio of fermentation products are being investigated by in vivo NMR spectroscopy.

  11. Regulation of alcohol fermentation by Escherichia coli

    SciTech Connect

    Clark, D.P.

    1990-01-01

    The purpose of this project is to elucidate the way in which the synthesis of ethanol and related fermentation products are regulated in the facultative anaerobe Escherichia coli. We are also investigating the control of other genes required for anaerobic growth. We have isolated both structural and regulatory mutations affecting the expression of alcohol dehydrogenase, the enzyme responsible for the final step in alcohol synthesis. Some of these regulatory mutations also affect other anaerobically induced genes. The adh gene has been cloned and sequenced. The ADH protein is one of the largest highly expressed proteins in E. coli and requires approximately 2700bp of DNA for its coding sequence. We have also isolated mutations affecting the fermentative lactate dehydrogenase and have recently cloned the ldh gene. In consequence it is now possible to construct E. coli strains defective in the production of any one or more of their normal fermentation products (i.e. formate, acetate, lactate, ethanol and succinate). The factors affecting ratio of fermentation products are being investigated by in vivo NMR spectroscopy.

  12. Long term effects of Escherichia coli mastitis.

    PubMed

    Blum, Shlomo E; Heller, Elimelech D; Leitner, Gabriel

    2014-07-01

    Escherichia coli is one of the most frequently diagnosed causes of bovine mastitis, and is typically associated with acute, clinical mastitis. The objective of the present study was to evaluate the long term effects of intramammary infections by E. coli on milk yield and quality, especially milk coagulation. Twenty-four Israeli Holstein cows diagnosed with clinical mastitis due to intramammary infection by E. coli were used in this study. Mean lactation number, days in milk (DIM) and daily milk yield (DMY) at the time of infection was 3.3 ± 1.3, 131.7 days ± 78.6 and 45.7 L ± 8.4, respectively. DMY, milk constituents, somatic cells count (SCC), differential leukocytes count and coagulation parameters were subsequently assessed. Two patterns of inflammation were identified: 'short inflammation', characterized by <15% decrease in DMY and <30 days until return to normal (n = 5), and 'long inflammation', characterized by >15% decrease in DMY and >30 days to reach a new maximum DMY (n = 19). The estimated mean loss of marketable milk during the study was 200 L/cow for 'short inflammation' cases, and 1,500 L/cow for 'long inflammation' ones. Significant differences between 'short' and 'long inflammation' effects were found in almost all parameters studied. Long-term detrimental effects on milk quality were found regardless of clinical or bacteriological cure of affected glands.

  13. Environmental Escherichia coli: Ecology and public health implications - A review

    USGS Publications Warehouse

    Jang, Jeonghwan; Hur, Hor-Gil; Sadowsky, Michael J.; Byappanahalli, Muruleedhara; Yan, Tao; Ishii, Satoshi

    2017-01-01

    Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm-blooded animals, including humans, and is often discharged into the environment through feces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent fecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extra-intestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a fecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long-term survival. Large-scale studies of population genetics provide the diversity and complexity of E. coli strains in various environments, affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments in regards to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed.

  14. Multidrug-resistant Escherichia coli in Asia: epidemiology and management.

    PubMed

    Sidjabat, Hanna E; Paterson, David L

    2015-05-01

    Escherichia coli has become multiresistant by way of production of a variety of β-lactamases. The prevalence of CTX-M-producing E. coli has reached 60-79% in certain parts of Asia. The acquisition of CTX-M plasmids by E. coli sequence type 131, a successful clone of E. coli, has caused further dissemination of CTX-M-producing E. coli. The prevalence of carbapenemase-producing E. coli, especially Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase (NDM)-producing E. coli has been increasing in Asia. K. pneumoniae carbapenemase and NDM have now been found in E. coli sequence type 131. The occurrence of NDM-producing E. coli is a major concern particularly in the Indian subcontinent, but now elsewhere in Asia as well. There are multiple reasons why antibiotic resistance in E. coli in Asia has reached such extreme levels. Approaches beyond antibiotic therapy, such as prevention of antibiotic resistance by antibiotic stewardship and protecting natural microbiome, are strategies to avoid further spread of antibiotic resistance.

  15. Diarrheagenic Escherichia coli in Children from Costa Rica

    PubMed Central

    Pérez, Cristian; Gómez-Duarte, Oscar G.; Arias, María L.

    2010-01-01

    More than 5,000 diarrheal cases per year receive medical care at the National Children's Hospital of Costa Rica, and nearly 5% of them require hospitalization. A total of 173 Escherichia coli strains isolated from children with diarrhea were characterized at the molecular, serologic, and phenotypic level. Multiplex and duplex polymerase chain reactions were used to detect the six categories of diarrheagenic E. coli. Thirty percent (n = 52) of the strains were positive, indicating a high prevalence among the pediatric population. Enteropathogenic E. coli and enteroinvasive E. coli pathotypes were the most prevalent (21% and 19%, respectively). Pathogenic strains were distributed among the four E. coli phylogenetic groups A, B1, B2, and D, with groups A and B1 the most commonly found. This study used molecular typing to evaluate the prevalence of diarrheagenic E. coli reported in Costa Rica and demonstrated the importance of these pathotypes in the pediatric population. PMID:20682870

  16. Experimental Escherichia coli O157:H7 carriage in calves.

    PubMed Central

    Brown, C A; Harmon, B G; Zhao, T; Doyle, M P

    1997-01-01

    Nine weaned calves (6 to 8 weeks of age) were given 10(10) CFU of a five-strain mixture of enterohemorrhagic Escherichia coli O157:H7 by oral-gastric intubation. After an initial brief period of pyrexia in three calves and transient mild diarrhea in five calves, calves were clinically normal throughout the 13- to 27-day study. The population of E. coli O157:H7 in the faces decreased dramatically in all calves during the first 2 weeks after inoculation. Thereafter, small populations of E. coli O157:H7 persisted in all calves, where they were detected intermittently in the feces and rumen contents. While withholding food increased fecal shedding of E. coli O157:H7 by 1 to 2 log10/g in three of four calves previously shedding small populations of E. coli O157:H7, the effect of fasting on fecal shedding of E. coli O157:H7 was variable in calves shedding larger populations. At necropsy, E. coli O157:H7 was not isolated from sites outside the alimentary tract. E. coli O157:H7 was isolated from the forestomach or colon of all calves at necropsy. Greater numbers of E. coli O157:H7 were present in the gastrointestinal contents than in the corresponding mucosal sections, and there was no histologic or immunohistochemical evidence of E. coli O157:H7 adhering to the mucosa. In conclusion, under these experimental conditions, E. coli O157:H7 is not pathogenic in weaned calves, and while it does not appear to colonize mucosal surfaces for extended periods, E. coli O157:H7 persists in the contents of the rumen and colon as a source for fecal shedding. PMID:8979335

  17. Draft Genome Sequence of Uropathogenic Escherichia coli Strain NB8

    PubMed Central

    Mi, Zu-huang; Wang, Chun-xin; Zhu, Jian-ming

    2016-01-01

    Escherichia coli NB8 is a clinical pyelonephritis isolate. Here, we report the draft genome sequence of uropathogenic E. coli NB8, which contains drug resistance genes encoding resistance to beta-lactams, aminoglycosides, quinolones, macrolides, colistin, sulfonamide-trimethoprim, and tetracycline. NB8 infects the kidney and bladder, making it an important tool for studying E. coli pathogenesis. PMID:27609920

  18. Development of an E. coli 0157:H7 Specific Probe

    DTIC Science & Technology

    1994-07-01

    E . coli strain O157:H7 is an organism causing severe bloody diarrhea in humans. It’s often contracted by ingestion of contaminated food. Present...problems of present methods and provide better health care. The 60 megadalton plasmid of E coli strain 0157:H7 was isolated by a modification of the Magic...molecule was used to transform competent DH5 E . coli cells. Approximately 35 clones were obtained from the 0157H7 plasmid library. This report ends

  19. E. COLI VARIABILITY IN WATER UNDER THE EFFECT OF OZONE

    DTIC Science & Technology

    As a result of the effect of ozone, E . coli underwent significant morphological, cultural and biochemical changes. Ozonized bacteria lost the...gas formation was absent in the majority of E . coli variants which developed during incubation of the secondary fermentation sample at 43 C. As a...result of the ozonization of water a depression was established in the dehydrogenase of E . coli in respect to carbohydrates (except saccharose), alcohols

  20. Cytotoxic Escherichia coli strains encoding colibactin colonize laboratory mice.

    PubMed

    García, Alexis; Mannion, Anthony; Feng, Yan; Madden, Carolyn M; Bakthavatchalu, Vasudevan; Shen, Zeli; Ge, Zhongming; Fox, James G

    2016-12-01

    Escherichia coli strains have not been fully characterized in laboratory mice and are not currently excluded from mouse colonies. Colibactin (Clb), a cytotoxin, has been associated with inflammation and cancer in humans and animals. We performed bacterial cultures utilizing rectal swab, fecal, and extra intestinal samples from clinically unaffected or affected laboratory mice. Fifty-one E. coli were isolated from 45 laboratory mice, identified biochemically, and selected isolates were serotyped. The 16S rRNA gene was amplified and sequenced for specific isolates, PCR used for clbA and clbQ gene amplification, and phylogenetic group identification was performed on all 51 E. coli strains. Clb genes were sequenced and selected E. coli isolates were characterized using a HeLa cell cytotoxicity assay. Forty-five of the 51 E. coli isolates (88%) encoded clbA and clbQ and belonged to phylogenetic group B2. Mouse E. coli serotypes included: O2:H6, O-:H-, OM:H+, and O22:H-. Clb-encoding O2: H6 mouse E. coli isolates were cytotoxic in vitro. A Clb-encoding E. coli was isolated from a clinically affected genetically modified mouse with cystic endometrial hyperplasia. Our findings suggest that Clb-encoding E. coli colonize laboratory mice and may induce clinical and subclinical diseases that may impact experimental mouse models.

  1. Using zebra mussels to monitor Escherichia coli in environmental waters.

    PubMed

    Selegean, J P; Kusserow, R; Patel, R; Heidtke, T M; Ram, J L

    2001-01-01

    Use of the zebra mussel (Dreissena polymorpha) as an indicator of previously elevated bacteria concentrations in a watershed was examined. The ability of the zebra mussel to accumulate and purge Escherichia coli over several days was investigated in both laboratory and field experiments. In laboratory experiments, periodic enumeration of E. coli in mussels that had been exposed to a dilute solution of raw sewage demonstrated that (i) maximum concentrations of E. coli are reached within a few hours of exposure to sewage, (ii) the tissue concentration attained is higher than the concentration in the ambient water, and (iii) the E. coli concentrations take several days to return to preexposure concentrations when mussels are subsequently placed in sterile water. In field experiments conducted in southeast Michigan in the Clinton River watershed, brief increases in E. coli concentrations in the water were accompanied by increases in mussel concentrations of E. coli that lasted 2 or 3 d. The ability of mussels to retain and to concentrate E. coli made it possible to detect E. coli in the environment under conditions that conventional monitoring may often miss. Sampling caged mussels in a river and its tributaries may enable watershed managers to reduce the sampling frequency normally required to identify critical E. coli sources, thereby providing a more cost-effective river monitoring strategy for bacterial contamination.

  2. Rapid Sterilization of Escherichia coli by Solution Plasma Process

    NASA Astrophysics Data System (ADS)

    Andreeva, Nina; Ishizaki, Takahiro; Baroch, Pavel; Saito, Nagahiro

    2012-12-01

    Solution plasma (SP), which is a discharge in the liquid phase, has the potential for rapid sterilization of water without chemical agents. The discharge showed a strong sterilization performance against Escherichia coli bacteria. The decimal value (D value) of the reduction time for E. coli by this system with an electrode distance of 1.0 mm was estimated to be approximately 1.0 min. Our discharge system in the liquid phase caused no physical damage to the E. coli and only a small increase in the temperature of the aqueous solution. The UV light generated by the discharge was an important factor in the sterilization of E. coli.

  3. Behavior of enteroaggregative Escherichia coli, non-O157-shiga toxin-producing E. coli, enteroinvasive E. coli, enteropathogenic E. coli and enterotoxigenic E. coli strains on mung bean seeds and sprout.

    PubMed

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Bautista-De León, Haydee; Vázquez-Barrios, Ma Estela; Gordillo-Martínez, Alberto J; Castro-Rosas, Javier

    2013-09-16

    The behavior of enteroaggregative Escherichia coli (EAEC), non-O157 shiga toxin-producing E. coli (non-O157-STEC), enteroinvasive E. coli (EIEC), enterotoxigenic E. coli (ETEC) and enteropathogenic E. coli (EPEC) on mung bean seeds at 25±2 °C and during germination and sprouting of mung bean seeds at 20±2 ° and 30±2 °C and on mung bean sprouts at 3±2 °C was determined. When mung bean seeds were inoculated with EAEC, non-O157 STEC, EIEC, EPEC or ETEC strains, all these diarrheagenic E. coli pathotypes (DEPs) survived at least 90 days on mung bean seeds at 25±2 °C. All DEPs grew during germination and sprouting of seeds, reaching counts of approximately 5 Log and 7 Log CFU/g after 2 days at 20±2 ° and 30±2 °C, respectively. However, when the sprouts were inoculated after 1 day of seeds germination and stored at 20±2 ° or 30±2 °C, no growth was observed for any DEPs during sprouting at 20±2 °C per 9 d; however, a significant increase in the concentration of DEPs of approximately 0.7 log CFU/g was observed during sprouting at 30±2 °C after 1 day of sprout contamination. Refrigeration reduced the number of viable DEPs strains on sprouts after 10 days in storage; nevertheless, these decreases have no practical significance in the safety of the sprouts.

  4. Cyclomodulins in urosepsis strains of Escherichia coli.

    PubMed

    Dubois, Damien; Delmas, Julien; Cady, Anne; Robin, Frédéric; Sivignon, Adeline; Oswald, Eric; Bonnet, Richard

    2010-06-01

    Determinants of urosepsis in Escherichia coli remain incompletely defined. Cyclomodulins (CMs) are a growing functional family of toxins that hijack the eukaryotic cell cycle. Four cyclomodulin types are actually known in E. coli: cytotoxic necrotizing factors (CNFs), cycle-inhibiting factor (Cif), cytolethal distending toxins (CDTs), and the pks-encoded toxin. In the present study, the distribution of CM-encoding genes and the functionality of these toxins were investigated in 197 E. coli strains isolated from patients with community-acquired urosepsis (n = 146) and from uninfected subjects (n = 51). This distribution was analyzed in relation to the phylogenetic background, clinical origin, and antibiotic resistance of the strains. It emerged from this study that strains harboring the pks island and the cnf1 gene (i) were strongly associated with the B2 phylogroup (P, <0.001), (ii) frequently harbored both toxin-encoded genes in phylogroup B2 (33%), and (iii) were predictive of a urosepsis origin (P, <0.001 to 0.005). However, the prevalences of the pks island among phylogroup B2 strains, in contrast to those of the cnf1 gene, were not significantly different between fecal and urosepsis groups, suggesting that the pks island is more important for the colonization process and the cnf1 gene for virulence. pks- or cnf1-harboring strains were significantly associated with susceptibility to antibiotics (amoxicillin, cotrimoxazole, and quinolones [P, <0.001 to 0.043]). Otherwise, only 6% and 1% of all strains harbored the cdtB and cif genes, respectively, with no particular distribution by phylogenetic background, antimicrobial susceptibility, or clinical origin.

  5. The extracellular RNA complement of Escherichia coli

    PubMed Central

    Ghosal, Anubrata; Upadhyaya, Bimal Babu; Fritz, Joëlle V; Heintz-Buschart, Anna; Desai, Mahesh S; Yusuf, Dilmurat; Huang, David; Baumuratov, Aidos; Wang, Kai; Galas, David; Wilmes, Paul

    2015-01-01

    The secretion of biomolecules into the extracellular milieu is a common and well-conserved phenomenon in biology. In bacteria, secreted biomolecules are not only involved in intra-species communication but they also play roles in inter-kingdom exchanges and pathogenicity. To date, released products, such as small molecules, DNA, peptides, and proteins, have been well studied in bacteria. However, the bacterial extracellular RNA complement has so far not been comprehensively characterized. Here, we have analyzed, using a combination of physical characterization and high-throughput sequencing, the extracellular RNA complement of both outer membrane vesicle (OMV)-associated and OMV-free RNA of the enteric Gram-negative model bacterium Escherichia coli K-12 substrain MG1655 and have compared it to its intracellular RNA complement. Our results demonstrate that a large part of the extracellular RNA complement is in the size range between 15 and 40 nucleotides and is derived from specific intracellular RNAs. Furthermore, RNA is associated with OMVs and the relative abundances of RNA biotypes in the intracellular, OMV and OMV-free fractions are distinct. Apart from rRNA fragments, a significant portion of the extracellular RNA complement is composed of specific cleavage products of functionally important structural noncoding RNAs, including tRNAs, 4.5S RNA, 6S RNA, and tmRNA. In addition, the extracellular RNA pool includes RNA biotypes from cryptic prophages, intergenic, and coding regions, of which some are so far uncharacterised, for example, transcripts mapping to the fimA-fimL and ves-spy intergenic regions. Our study provides the first detailed characterization of the extracellular RNA complement of the enteric model bacterium E. coli. Analogous to findings in eukaryotes, our results suggest the selective export of specific RNA biotypes by E. coli, which in turn indicates a potential role for extracellular bacterial RNAs in intercellular communication. PMID:25611733

  6. ELECTROPHORETIC MOBILITIES OF ESCHERICHIA COLI 0157:H7 AND WILD-TYPE ESCHERICHIA COLI STRAINS

    EPA Science Inventory

    The electrophoretic mobility (EPM) of a number of human-virulent and "wild-type" Escherichia coli strains in phosphate buffered water was measured. The impact of pH, ionic strength, cation type (valence) and concentration, and bacterial strain on the EPM was investigated. Resul...

  7. Recruitment of CD55 and CD66e brush border-associated glycosylphosphatidylinositol-anchored proteins by members of the Afa/Dr diffusely adhering family of Escherichia coli that infect the human polarized intestinal Caco-2/TC7 cells.

    PubMed

    Guignot, J; Peiffer, I; Bernet-Camard, M F; Lublin, D M; Carnoy, C; Moseley, S L; Servin, A L

    2000-06-01

    The Afa/Dr family of diffusely adhering Escherichia coli (Afa/Dr DAEC) includes bacteria expressing afimbrial adhesins (AFA), Dr hemagglutinin, and fimbrial F1845 adhesin. We show that infection of human intestinal Caco-2/TC7 cells by the Afa/Dr DAEC strains C1845 and IH11128 is followed by clustering of CD55 around adhering bacteria. Mapping of CD55 epitopes involved in CD55 clustering by Afa/Dr DAEC was conducted using CD55 deletion mutants expressed by stable transfection in CHO cells. Deletion in the short consensus repeat 1 (SCR1) domain abolished Afa/Dr DAEC-induced CD55 clustering. In contrast, deletion in the SCR4 domain does not modify Afa/Dr DAEC-induced CD55 clustering. We show that the brush border-associated glycosylphosphatidylinositol (GPI)-anchored protein CD66e (carcinoembryonic antigen) is recruited by the Afa/Dr DAEC strains C1845 and IH11128. This conclusion is based on the observations that (i) infection of Caco-2/TC7 cells by Afa/Dr DAEC strains is followed by clustering of CD66e around adhering bacteria and (ii) Afa/Dr DAEC strains bound efficiently to stably transfected HeLa cells expressing CD66e, accompanied by CD66e clustering around adhering bacteria. Inhibition assay using monoclonal antibodies directed against CD55 SCR domains, and polyclonal anti-CD55 and anti-CD66e antibodies demonstrate that CD55 and CD66e function as a receptors for the C1845 and IH11128 bacteria. Moreover, using structural draE gene mutants, we found that a mutant in which cysteine replaced aspartic acid at position 54 displayed conserved binding capacity but failed to induce CD55 and CD66e clustering. Taken together, these data give new insights into the mechanisms by which Afa/Dr DAEC induces adhesin-dependent cross talk in the human polarized intestinal epithelial cells by mobilizing brush border-associated GPI-anchored proteins known to function as transducing molecules.

  8. Escherichia coli survival in waters: temperature dependence.

    PubMed

    Blaustein, R A; Pachepsky, Y; Hill, R L; Shelton, D R; Whelan, G

    2013-02-01

    Knowing the survival rates of water-borne Escherichia coli is important in evaluating microbial contamination and making appropriate management decisions. E. coli survival rates are dependent on temperature, a dependency that is routinely expressed using an analogue of the Q₁₀ model. This suggestion was made 34 years ago based on 20 survival curves taken from published literature, but has not been revisited since then. The objective of this study was to re-evaluate the accuracy of the Q₁₀ equation, utilizing data accumulated since 1978. We assembled a database of 450 E. coli survival datasets from 70 peer-reviewed papers. We then focused on the 170 curves taken from experiments that were performed in the laboratory under dark conditions to exclude the effects of sunlight and other field factors that could cause additional variability in results. All datasets were tabulated dependencies "log concentration vs. time." There were three major patterns of inactivation: about half of the datasets had a section of fast log-linear inactivation followed by a section of slow log-linear inactivation; about a quarter of the datasets had a lag period followed by log-linear inactivation; and the remaining quarter were approximately linear throughout. First-order inactivation rate constants were calculated from the linear sections of all survival curves and the data grouped by water sources, including waters of agricultural origin, pristine water sources, groundwater and wells, lakes and reservoirs, rivers and streams, estuaries and seawater, and wastewater. Dependency of E. coli inactivation rates on temperature varied among the water sources. There was a significant difference in inactivation rate values at the reference temperature between rivers and agricultural waters, wastewaters and agricultural waters, rivers and lakes, and wastewater and lakes. At specific sites, the Q₁₀ equation was more accurate in rivers and coastal waters than in lakes making the value of

  9. Biosynthesis of phosphatidyl glycerophosphate in Escherichia coli.

    PubMed

    Chang, Y Y; Kennedy, E P

    1967-09-01

    An enzyme (L-glycerol 3-phosphate: CMP phosphatidyltransferase) catalyzing the synthesis of phosphatidyl glycerophosphate from CDP-diglyceride and L-glycerol 3-phosphate has been rendered soluble by treatment of the particulate, membrane-containing fraction of E. coli with Triton X-100 and has been partially purified. The enzyme, devoid of phosphatidyl glycerophosphatase activity, is specific for L-glycerol 3-phosphate and is completely dependent upon added Mg(++) or Mn(++) for activity. It has high affinity for CDP-diglyceride and can be used for the assay of this nucleotide. Other properties of the enzyme are also described.

  10. Genetic and Physical Structure of Salmonella-coli Phage Hybrids and Development of New Generalized Transducing Hybrid Phages for E. Coli.

    DTIC Science & Technology

    1984-05-01

    Walter Reed Army Institute of Research began searching for E . coli -S. typhimurium recombinants in 1971. After isolating E . coli -S. typhimurium hybrids...which are common hosts for the various coli and Salmonella phages, we developed efficient selective methods of hybrids between Salmonella and E . coli phages

  11. Expanding ester biosynthesis in Escherichia coli.

    PubMed

    Rodriguez, Gabriel M; Tashiro, Yohei; Atsumi, Shota

    2014-04-01

    To expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to facilitate ester formation. The diversity of CoA molecules found in nature in combination with various alcohol biosynthetic pathways allows for the biosynthesis of a multitude of esters. Small to medium volatile esters have extensive applications in the flavor, fragrance, cosmetic, solvent, paint and coating industries. The present work enables the production of these compounds by designing several ester pathways in E. coli. The engineered pathways generated acetate esters of ethyl, propyl, isobutyl, 2-methyl-1-butyl, 3-methyl-1-butyl and 2-phenylethyl alcohols. In particular, we achieved high-level production of isobutyl acetate from glucose (17.2 g l(-1)). This strategy was expanded to realize pathways for tetradecyl acetate and several isobutyrate esters.

  12. [Enteroinvasive Escherichia coli. Pathogenesis and epidemiology].

    PubMed

    Prats, G; Llovet, T

    1995-03-01

    Enteroinvasive Escherichia coli (EIEC) is an intestinal pathogen causing enteritis, with a similar pathogenic mechanism to that of Shigella, which causes an epithelial invasion of the large bowel leading to inflammation and ulceration of the mucosa. The patients often develop the symptoms of bacillary dysentery. The EIEC strains are atypical in their biochemical reactions and may ferment lactose late or not at all, are lysine decarboxilase negative, and non motile. In addition, most EIEC strains express somatic antigens which are either strongly related or identical to Shigella antigens. EIEC invasion is mediated by a large plasmid (140 MDa) coding for the production of several outer membrane proteins involved in invasiveness. These strains have been isolated with some regularity in South America, the Extreme Orient, and Eastern Europe. In Spain the incidence of enteroinvasive E. coli is extraordinarily low (0.2%), the serogroup O124 being the most frequently isolated. EIEC enteritis has been associated to sporadic cases occurring in travellers. Occasional outbreaks related to ingestion of contaminated water or food and person to person have been reported.

  13. Independence of replisomes in Escherichia coli chromosomalreplication

    SciTech Connect

    Breier, Adam M.; Weier, Heinz-Ulrich G.; Cozzarelli, Nicholas R.

    2005-03-13

    In Escherichia coli DNA replication is carried out by the coordinated action of the proteins within a replisome. After replication initiation, the two bidirectionally oriented replisomes from a single origin are colocalized into higher-order structures termed replication factories. The factory model postulated that the two replisomes are also functionally coupled. We tested this hypothesis by using DNA combing and whole-genome microarrays. Nascent DNA surrounding oriC in single, combed chromosomes showed instead that one replisome, usually the leftward one, was significantly ahead of the other 70% of the time. We next used microarrays to follow replication throughout the genome by measuring DNA copy number. We found in multiple E. coli strains that the replisomes are independent, with the leftward replisome ahead of the rightward one. The size of the bias was strain-specific, varying from 50 to 130 kb in the array results. When we artificially blocked one replisome, the other continued unabated, again demonstrating independence. We suggest an improved version of the factory model that retains the advantages of threading DNA through colocalized replisomes at about equal rates, but allows the cell flexibility to overcome obstacles encountered during elongation.

  14. Nucleotide excision repair in Escherichia coli.

    PubMed Central

    Van Houten, B

    1990-01-01

    One of the best-studied DNA repair pathways is nucleotide excision repair, a process consisting of DNA damage recognition, incision, excision, repair resynthesis, and DNA ligation. Escherichia coli has served as a model organism for the study of this process. Recently, many of the proteins that mediate E. coli nucleotide excision have been purified to homogeneity; this had led to a molecular description of this repair pathway. One of the key repair enzymes of this pathway is the UvrABC nuclease complex. The individual subunits of this enzyme cooperate in a complex series of partial reactions to bind to and incise the DNA near a damaged nucleotide. The UvrABC complex displays a remarkable substrate diversity. Defining the structural features of DNA lesions that provide the specificity for damage recognition by the UvrABC complex is of great importance, since it represents a unique form of protein-DNA interaction. Using a number of in vitro assays, researchers have been able to elucidate the action mechanism of the UvrABC nuclease complex. Current research is devoted to understanding how these complex events are mediated within the living cell. PMID:2181258

  15. Shear alters motility of Escherichia coli

    NASA Astrophysics Data System (ADS)

    Molaei, Mehdi; Jalali, Maryam; Sheng, Jian

    2013-11-01

    Understanding of locomotion of microorganisms in shear flows drew a wide range of interests in microbial related topics such as biological process including pathogenic infection and biophysical interactions like biofilm formation on engineering surfaces. We employed microfluidics and digital holography microscopy to study motility of E. coli in shear flows. We controlled the shear flow in three different shear rates: 0.28 s-1, 2.8 s-1, and 28 s-1 in a straight channel with the depth of 200 μm. Magnified holograms, recorded at 15 fps with a CCD camera over more than 20 minutes, are analyzed to obtain 3D swimming trajectories and subsequently used to extract shear responses of E.coli. Thousands of 3-D bacterial trajectories are tracked. The change of bacteria swimming characteristics including swimming velocity, reorientation, and dispersion coefficient are computed directly for individual trajectory and ensemble averaged over thousands of realizations. The results show that shear suppresses the bacterial dispersions in bulk but promote dispersions near the surface contrary to those in quiescent flow condition. Ongoing analyses are focusing to quantify effect of shear rates on tumbling frequency and reorientation of cell body, and its implication in locating the hydrodynamic mechanisms for shear enhanced angular scattering. NIH, NSF, GoMRI.

  16. Chemotaxis Toward Sugars in Escherichia coli

    PubMed Central

    Adler, Julius; Hazelbauer, Gerald L.; Dahl, M. M.

    1973-01-01

    Using a quantitative assay for measuring chemotaxis, we tested a variety of sugars and sugar derivatives for their ability to attract Escherichia coli bacteria. The most effective attractants, i.e., those that have thresholds near 10−5 M or below, are N-acetyl-d-glucosamine, 6-deoxy-d-glucose, d-fructose, d-fucose, 1-d-glycerol-β-d-galactoside, galactitol, d-galactose, d-glucosamine, d-glucose, α-d-glucose-1-phosphate, lactose, maltose, d-mannitol, d-mannose, methyl-β-d-galactoside, methyl-β-d-glucoside, d-ribose, d-sorbitol, and trehalose. Lactose, and probably d-glucose-1-phosphate, are attractive only after conversion to the free monosaccharide, while the other attractants do not require breakdown for taxis. Nine different chemoreceptors are involved in detecting these various attractants. They are called the N-acetyl-glucosamine, fructose, galactose, glucose, maltose, mannitol, ribose, sorbitol, and trehalose chemoreceptors; the specificity of each was studied. The chemoreceptors, with the exception of the one for d-glucose, are inducible. The galactose-binding protein serves as the recognition component of the galactose chemoreceptor. E. coli also has osmotically shockable binding activities for maltose and d-ribose, and these appear to serve as the recognition components for the corresponding chemoreceptors. PMID:4580570

  17. Expanding ester biosynthesis in Escherichia coli

    PubMed Central

    Rodriguez, Gabriel M; Tashiro, Yohei; Atsumi, Shota

    2015-01-01

    To expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to facilitate ester formation. The diversity of CoA molecules found in nature in combination with various alcohol biosynthetic pathways allows for the biosynthesis of a multitude of esters. Small to medium volatile esters have extensive applications in the flavor, fragrance, cosmetic, solvent, paint and coating industries. The present work enables the production of these compounds by designing several ester pathways in E. coli. The engineered pathways generated acetate esters of ethyl, propyl, isobutyl, 2-methyl-1-butyl, 3-methyl-1-butyl and 2-phenylethyl alcohols. In particular, we achieved high-level production of isobutyl acetate from glucose (17.2 g l−1). This strategy was expanded to realize pathways for tetradecyl acetate and several isobutyrate esters. PMID:24609358

  18. The thermal impulse response of Escherichia coli

    PubMed Central

    Paster, Eli; Ryu, William S.

    2008-01-01

    Swimming Escherichia coli responds to changes in temperature by modifying its motor behavior. Previous studies using populations of cells have shown that E. coli accumulate in spatial thermal gradients, but these experiments did not cleanly separate thermal responses from chemotactic responses. Here we have isolated the thermal response by studying the behavior of single, tethered cells. The motor output of cells grown at 33°C was measured at constant temperature, from 10° to 40°C, and in response to small, impulsive increases in temperature, from 23° to 43°C. The thermal impulse response at temperatures < 31°C is similar to the chemotactic impulse response: Both follow a similar time course, share the same directionality, and show biphasic characteristics. At temperatures > 31°C, some cells show an inverted response, switching from warm- to cold-seeking behavior. The fraction of inverted responses increases nonlinearly with temperature, switching steeply at the preferred temperature of 37°C. PMID:18385380

  19. A Tripartite Fusion, FaeG-FedF-LT192A2:B, of Enterotoxigenic Escherichia coli (ETEC) Elicits Antibodies That Neutralize Cholera Toxin, Inhibit Adherence of K88 (F4) and F18 Fimbriae, and Protect Pigs against K88ac/Heat-Labile Toxin Infection ▿

    PubMed Central

    Ruan, Xiaosai; Liu, Mei; Casey, Thomas A.; Zhang, Weiping

    2011-01-01

    Enterotoxigenic Escherichia coli (ETEC) strains expressing K88 (F4) or F18 fimbriae and heat-labile (LT) and/or heat-stable (ST) toxins are the major cause of diarrhea in young pigs. Effective vaccines inducing antiadhesin (anti-K88 and anti-F18) and antitoxin (anti-LT and anti-ST) immunity would provide broad protection to young pigs against ETEC. In this study, we genetically fused nucleotides coding for peptides from K88ac major subunit FaeG, F18 minor subunit FedF, and LT toxoid (LT192) A2 and B subunits for a tripartite adhesin-adhesin-toxoid fusion (FaeG-FedF-LT192A2:B). This fusion was used for immunizations in mice and pigs to assess the induction of antiadhesin and antitoxin antibodies. In addition, protection by the elicited antiadhesin and antitoxin antibodies against a porcine ETEC strain was evaluated in a gnotobiotic piglet challenge model. The data showed that this FaeG-FedF-LT192A2:B fusion elicited anti-K88, anti-F18, and anti-LT antibodies in immunized mice and pigs. In addition, the anti-porcine antibodies elicited neutralized cholera toxin and inhibited adherence against both K88 and F18 fimbriae. Moreover, immunized piglets were protected when challenged with ETEC strain 30302 (K88ac/LT/STb) and did not develop clinical disease. In contrast, all control nonvaccinated piglets developed severe diarrhea and dehydration after being challenged with the same ETEC strain. This study clearly demonstrated that this FaeG-FedF-LT192A2:B fusion antigen elicited antibodies that neutralized LT toxin and inhibited the adherence of K88 and F18 fimbrial E. coli strains and that this fusion could serve as an antigen for vaccines against porcine ETEC diarrhea. In addition, the adhesin-toxoid fusion approach used in this study may provide important information for developing effective vaccines against human ETEC diarrhea. PMID:21813665

  20. Genomic Comparative Study of Bovine Mastitis Escherichia coli

    PubMed Central

    Kempf, Florent; Slugocki, Cindy; Blum, Shlomo E.; Leitner, Gabriel; Germon, Pierre

    2016-01-01

    Escherichia coli, one of the main causative agents of bovine mastitis, is responsible for significant losses on dairy farms. In order to better understand the pathogenicity of E. coli mastitis, an accurate characterization of E. coli strains isolated from mastitis cases is required. By using phylogenetic analyses and whole genome comparison of 5 currently available mastitis E. coli genome sequences, we searched for genotypic traits specific for mastitis isolates. Our data confirm that there is a bias in the distribution of mastitis isolates in the different phylogenetic groups of the E. coli species, with the majority of strains belonging to phylogenetic groups A and B1. An interesting feature is that clustering of strains based on their accessory genome is very similar to that obtained using the core genome. This finding illustrates the fact that phenotypic properties of strains from different phylogroups are likely to be different. As a consequence, it is possible that different strategies could be used by mastitis isolates of different phylogroups to trigger mastitis. Our results indicate that mastitis E. coli isolates analyzed in this study carry very few of the virulence genes described in other pathogenic E. coli strains. A more detailed analysis of the presence/absence of genes involved in LPS synthesis, iron acquisition and type 6 secretion systems did not uncover specific properties of mastitis isolates. Altogether, these results indicate that mastitis E. coli isolates are rather characterized by a lack of bona fide currently described virulence genes. PMID:26809117

  1. [Verocytotoxigenic Escherichia coli--epidemiology, pathogenicity and antimicrobial resistance].

    PubMed

    Januszkiewicz, Aleksandra

    2012-01-01

    Verocytotoxigenic E. coli (VTEC) are one of the most common foodborne pathogen in human worldwide. High pathogenic potential of these organisms makes it often the cause of international outbreaks with numerous fatalities. This study presents the current knowledge on verocytotoxigenic E. coli: pathogenicity, drug resistance as well as the epidemiology of infections.

  2. Enterotoxigenic Escherichia coli Multilocus Sequence Types in Guatemala and Mexico

    PubMed Central

    Klena, John; Rodas, Claudia; Bourgeois, August Louis; Torres, Olga; Svennerholm, Ann-Mari; Sjöling, Åsa

    2010-01-01

    The genetic backgrounds of 24 enterotoxigenic Escherichia coli (ETEC) strains from Mexico and Guatemala expressing heat-stable toxin (ST) and coli surface antigen 6 (CS6) were analyzed. US travelers to these countries and resident children in Guatemala were infected by ETEC strains of sequence type 398, expressing STp and carrying genetically identical CS6 sequences. PMID:20031063

  3. Molecular serotyping of Escherichia coli: A verification and reclassification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Serotyping of E. coli, based on the O- (polysaccharide side chain) and H- (flagellar) antigens using antisera is a common practice for diagnostics, outbreak investigations, and epidemiological surveillance. The full set of E. coli serogroups comprises O-groups O1 to O181, with several O...

  4. [Acute diarrheal disease caused by enteropathogenic Escherichia coli in Colombia].

    PubMed

    Gómez-Duarte, Oscar G

    2014-10-01

    Intestinal Escherichia coli pathogens are leading causes of acute diarrheal disease in children less than 5 years in Latin America, Africa and Asia and a leading cause of death in children living in poorest communities in Africa and South East Asia. Studies on the role of E. coli pathogens in childhood diarrhea in Colombia and other countries in Latin America are limited due to the lack of detection assays in clinical laboratories at the main urban medical centers. Recent studies report that enterotoxigenic E. coli is the most common E. coli pathogens associated with diarrhea in children less than 5 years of age. Other E. coli pathotypes have been detected in children with diarrhea including enteropathogenic, enteroaggregative, shiga-toxin producing and diffusely adherent E. coli. It was also found that meat and vegetables at retail stores are contaminated with Shiga-toxin producing E. coli and enteroaggregative E. coli, suggesting that food products are involved in transmission and infection of the susceptible host. More studies are necessary to evaluate the mechanisms of transmission, the impact on the epidemiology of diarrheal disease, and management strategies and prevention of these pathogens affecting the pediatric population in Colombia.

  5. Characterization of enterohemorrhagic Escherichia coli on veal hides and carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enterohemorrhagic E. coli (EHEC) are Shiga toxin–producing Escherichia coli (STEC) associated with the most severe forms of foodborne illnesses. The United States Department of Agriculture (USDA) Food Safety Inspection Service (FSIS) has identified a higher percentage of non-O157 EHEC compared to E....

  6. Weak Electromagnetic Field Effects on Gene Expression in E. coli.

    DTIC Science & Technology

    2007-11-02

    and/or translation were altered by MFs. A cell-free E . coli system was used to determine whether or not MFs directly affect the translational or...inability to distinguish differences in transcription and translation in E . coli may be related to the coupled nature of these processes in the bacterial system.

  7. STUDY OF THE ACTION OF SODIUM LAURYLSULFATE ON E. COLI

    DTIC Science & Technology

    Sodium laurylsulfate (L.S.) lyses E . coli cells when their metabolism is halted or inhibited by any of a number of antimetabolites. Actively growing...L.S. has an extremely rapid lytic action on globular forms of E . coli . The probable mechanism of the cytolysis of nonmetabolizing whole cells is discussed.

  8. ACCELERATED METHOD FOR THE DETERMINATION OF E. COLI,

    DTIC Science & Technology

    A method was developed for preparing indicator paper slips for the determination of E . coli by the ’Bactostrip’ method (Foerg) when appraising the...quality of milk. The essence of the method is the exposure of E . coli on a strip of paper, impregnated with nutrient medium containing an indicator (triphenyltetrazolium chloride or other). (Author)

  9. Molecular Cloning of Actinomyces Bacteriophage DNA in E. Coli.

    DTIC Science & Technology

    2007-11-02

    recombinant clones revealed the presence of the expected phi63 DNA fragments that were used in the subcloning and they were stably maintained in E . coli . Further...feasibility of cloning of Actinomyces phage DNA fragments onto an E . coli expression vector.

  10. Use of bacteriophages in controlling E. coli in leafy vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteriophages are viruses that can infect and lys (kill) bacteria. These viruses are not harmful to humans and are present in the environment and many foods. Enterohemmorhagic E. coli (EHEC), like E. coli O157:H7, have been associated with contaminated bagged leafy green commodities. Outbreaks o...

  11. Escherichia coli and fecal coliforms in freshwater and estuarine sediments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has been known for some time that substantial populations of fecal coliforms and E. coli are harbored in freshwater bottom sediments, bank soils, and beach sands. However, the relative importance of sediments as bacterial habitats and as a source of water-borne fecal coliforms and E. coli has not...

  12. EcoCyc: Encyclopedia of Escherichia coli genes and metabolism.

    PubMed

    Karp, P D; Riley, M; Paley, S M; Pellegrini-Toole, A; Krummenacker, M

    1998-01-01

    The encyclopedia of Escherichia coli genes and metabolism (EcoCyc) is a database that combines information about the genome and the intermediary metabolism of E.coli. The database describes 3030 genes of E.coli , 695 enzymes encoded by a subset of these genes, 595 metabolic reactions that occur in E.coli, and the organization of these reactions into 123 metabolic pathways. The EcoCyc graphical user interface allows scientists to query and explore the EcoCyc database using visualization tools such as genomic-map browsers and automatic layouts of metabolic pathways. EcoCyc can be thought of as an electronic review article because of its copious references to the primary literature, and as a (qualitative) computational model of E.coli metabolism. EcoCyc is available at URL http://ecocyc.PangeaSystems.com/ecocyc/

  13. Phylogenetic Group Determination of Escherichia coli Isolated from Animals Samples

    PubMed Central

    Morcatti Coura, Fernanda; Diniz, Soraia de Araújo; Silva, Marcos Xavier; Mussi, Jamili Maria Suhet; Barbosa, Silvia Minharro; Lage, Andrey Pereira; Heinemann, Marcos Bryan

    2015-01-01

    This study analyzes the occurrence and distribution of phylogenetic groups of 391 strains of Escherichia coli isolated from poultry, cattle, and water buffalo. The frequency of the phylogroups was A = 19%, B1 = 57%, B2 = 2.3%, C = 4.6%, D = 2.8%, E = 11%, and F = 3.3%. Phylogroups A (P < 0.001) and F (P = 0.018) were associated with E. coli strains isolated from poultry, phylogroups B1 (P < 0.001) and E (P = 0.002) were associated with E. coli isolated from cattle, and phylogroups B2 (P = 0.003) and D (P = 0.017) were associated with E. coli isolated from water buffalo. This report demonstrated that some phylogroups are associated with the host analyzed and the results provide knowledge of the phylogenetic composition of E. coli from domestic animals. PMID:26421310

  14. Glycerol elicits energy taxis of Escherichia coli and Salmonella typhimurium.

    PubMed

    Zhulin, I B; Rowsell, E H; Johnson, M S; Taylor, B L

    1997-05-01

    Escherichia coli and Salmonella typhimurium show positive chemotaxis to glycerol, a chemical previously reported to be a repellent for E. coli. The threshold of the attractant response in both species was 10(-6) M glycerol. Glycerol chemotaxis was energy dependent and coincident with an increase in membrane potential. Metabolism of glycerol was required for chemotaxis, and when lactate was present to maintain energy production in the absence of glycerol, the increases in membrane potential and chemotactic response upon addition of glycerol were abolished. Methylation of a chemotaxis receptor was not required for positive glycerol chemotaxis in E. coli or S. typhimurium but is involved in the negative chemotaxis of E. coli to high concentrations of glycerol. We propose that positive chemotaxis to glycerol in E. coli and S. typhimurium is an example of energy taxis mediated via a signal transduction pathway that responds to changes in the cellular energy level.

  15. Molecular typing of avian pathogenic Escherichia coli colonies originating from outbreaks of E. coli peritonitis syndrome in chicken flocks.

    PubMed

    Landman, W J M; Buter, G J; Dijkman, R; van Eck, J H H

    2014-01-01

    Escherichia coli colonies isolated from the bone marrow of fresh dead hens of laying flocks with the E. coli peritonitis syndrome (EPS) were genotyped using pulsed-field gel electrophoresis (PFGE). Typing is important from an epidemiological point of view and also if the use of autogenous (auto)vaccines is considered. Birds with EPS originated from one house of each of three layer farms and one broiler breeder farm. Farms were considered as separate epidemiological units. In total, six flocks were examined including two successive flocks of one layer farm and the broiler breeder farm. E. coli colonies (one per bird) from nine to 16 hens of each flock were genotyped. The clonality of E. coli within birds was studied using five colonies of each of nine to 14 birds per flock. E. coli genotypes, which totalled 15, differed between farms and flocks except for two successive layer flocks that shared three genotypes. One to five genotypes were found per flock with one or two genotypes dominating each outbreak. Within hens, E. coli bacteria were always clonal. Colonies of the same PFGE type always had the same multilocus sequence type. However, four PFGE types shared sequence type 95. Neither PFGE types nor multilocus sequence types were unambiguously related to avian pathogenic E. coli from EPS. In cases where persistence of E. coli strains associated with EPS is found to occur frequently, routine genotyping to select strains for autovaccines should be considered.

  16. Effects of intravenous Escherichia coli (E. coli) dose on the pathophysiological response of colostrum-fed Jersey calves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to determine the effects of E. coli dose on the pathophysiological response of dairy calves following an intravenous challenge. Eighteen 3-week old colostrum-fed Jersey calves were completely randomized to 1 of 6 doses of E. coli. The challenge doses included 0, 105, 106, 107, 108,...

  17. Soil solarization reduces Escherichia coli O157:H7 and total Escherichia coli on cattle feedlot pen surfaces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feedlot pen soils are a source for transmission of Escherichia coli O157:H7, and therefore a target for preharvest strategies to reduce this pathogen in cattle. The objective of this study was to determine the ability of soil solarization to reduce E. coli O157:H7 in feedlot surface material (FSM)....

  18. Preparation of Soluble Proteins from Escherichia coli

    PubMed Central

    Wingfield, Paul T.

    2014-01-01

    Purification of human IL-1β is used in this unit as an example of the preparation of soluble proteins from E. coli. Bacteria containing IL-1β are lysed, and IL-1 β in the resulting supernatant is purified by anion-exchange chromatography, salt precipitation and cation-exchange chromatography, and then concentrated. Finally, the IL-1 β protein is applied to a gel-filtration column to separate it from remaining higher- and lower-molecular-weight contaminants, the purified protein is stored frozen or is lyophilized. The purification protocol described is typical for a protein that is expressed in fairly high abundance (i.e., >5% total protein) and accumulates in a soluble state. Also, the purification procedure serves as an example of how use classical protein purifications methods which may also be used in conjunction with the affinity-based methods now more commonly used. PMID:25367009

  19. Mechanism of Escherichia coli Resistance to Pyrrhocoricin

    PubMed Central

    Narayanan, Shalini; Modak, Joyanta K.; Ryan, Catherine S.; Garcia-Bustos, Jose; Davies, John K.

    2014-01-01

    Due to their lack of toxicity to mammalian cells and good serum stability, proline-rich antimicrobial peptides (PR-AMPs) have been proposed as promising candidates for the treatment of infections caused by antimicrobial-resistant bacterial pathogens. It has been hypothesized that these peptides act on multiple targets within bacterial cells, and therefore the likelihood of the emergence of resistance was considered to be low. Here, we show that spontaneous Escherichia coli mutants resistant to pyrrhocoricin arise at a frequency of approximately 6 × 10−7. Multiple independently derived mutants all contained a deletion in a nonessential gene that encodes the putative peptide uptake permease SbmA. Sensitivity could be restored to the mutants by complementation with an intact copy of the sbmA gene. These findings question the viability of the development of insect PR-AMPs as antimicrobials. PMID:24590485

  20. Animal models of enteroaggregative Escherichia coli infection

    PubMed Central

    Philipson, Casandra W.; Bassaganya-Riera, Josep; Hontecillas, Raquel

    2013-01-01

    Enteroaggregative Escherichia coli (EAEC) has been acknowledged as an emerging cause of gastroenteritis worldwide for over two decades. Epidemiologists are revealing the role of EAEC in diarrheal outbreaks as a more common occurrence than ever suggested before. EAEC induced diarrhea is most commonly associated with travelers, children and immunocompromised individuals however its afflictions are not limited to any particular demographic. Many attributes have been discovered and characterized surrounding the capability of EAEC to provoke a potent pro-inflammatory immune response, however cellular and molecular mechanisms underlying initiation, progression and outcomes are largely unknown. This limited understanding can be attributed to heterogeneity in strains and the lack of adequate animal models. This review aims to summarize current knowledge about EAEC etiology, pathogenesis and clinical manifestation. Additionally, current animal models and their limitations will be discussed along with the value of applying systems-wide approaches such as computational modeling to study host-EAEC interactions. PMID:23680797

  1. An overview of atypical enteropathogenic Escherichia coli.

    PubMed

    Hernandes, Rodrigo T; Elias, Waldir P; Vieira, Mônica A M; Gomes, Tânia A T

    2009-08-01

    The enteropathogenic Escherichia coli (EPEC) pathotype is currently divided into two groups, typical EPEC (tEPEC) and atypical EPEC (aEPEC). The property that distinguishes these two groups is the presence of the EPEC adherence factor plasmid, which is only found in tEPEC. aEPEC strains are emerging enteropathogens that have been detected worldwide. Herein, we review the serotypes, virulence properties, genetic relationships, epidemiology, reservoir and diagnosis of aEPEC, including those strains not belonging to the classical EPEC serogroups (nonclassical EPEC serogroups). The large variety of serotypes and genetic virulence properties of aEPEC strains from nonclassical EPEC serogroups makes it difficult to determine which strains are truly pathogenic.

  2. Escherichia coli fliAZY operon.

    PubMed Central

    Mytelka, D S; Chamberlin, M J

    1996-01-01

    We have cloned the Escherichia coli fliAZY operon, which contains the fliA gene (the alternative sigma factor sigma F) and two novel genes, fliZ and fliY. Transcriptional mapping of this operon shows two start sites, one of which is preceded by a canonical E sigma F-dependent consensus and is dependent on sigma F for expression in vivo and in vitro. We have overexpressed and purified sigma F and demonstrated that it can direct core polymerase to E sigma F-dependent promoters. FliZ and FliY are not required for motility but may regulate sigma F activity, perhaps in response to a putative cell density signal that may be detected by FliY, a member of the bacterial extracellular solute-binding protein family 3. PMID:8550423

  3. [Sensitivity to drugs of Escherichia coli strains isolated from poultry with coli septicemia].

    PubMed

    Giurov, B

    1985-01-01

    Investigations were carried out into the susceptibility of a total of 223 strains of Escherichia coli to therapeutic agents with the employment of the disk diffusion method. The organisms were isolated from internal organs and bone marrow of birds died of coli septicaemia. The serologic classification of the strains was defined with the use of 88 anti-group OK-agglutinating sera obtained through hyperimmunization of rabbits with the following Escherichia coli serotypes: 01-063, 068, 071, 073, 075, 078, 086, 0101, 0103, 0111-0114, 0119, 0124, 0129, 0135-0141, 0146, 0147, and 0149. It was found that serologically the strains referred as follows: 01-41 strains, 02-70 strains, 04-2 strains, 08-3 strains, 026-1 strain, 078-70 strains, 0111-2 strains, 0103-1 strain, 0141-1 strain. The number of untypable strains amounted to 32. Highest number of strains proved sensitive to colistin--96.06%, the remaining drugs following in a descending order: flumequine--95.65%, apramycin - 95.5%, gentamycin--93.72%, amoxicillin--93,8%, amikacin--88.57%, carbenicillin--86.88%, furazolidone--83,13%, and kanamycin--79.36%. High was the percent of strains resistant to tetracycline--66.17%, spectinomycin--61.67%, ampicillin--51.12%, chloramphenicol--50.23%, and streptomycin--44.84%.

  4. Escherichia coli Unsaturated Fatty Acid Synthesis

    PubMed Central

    Feng, Youjun; Cronan, John E.

    2009-01-01

    Although the unsaturated fatty acid (UFA) synthetic pathway of Escherichia coli is the prototype of such pathways, several unresolved issues have accumulated over the years. The key players are the fabA and fabB genes. Earlier studies of fabA transcription showed that the gene was transcribed from two promoters, with one being positively regulated by the FadR protein. The other weaker promoter (which could not be mapped with the technology then available) was considered constitutive because its function was independent of FadR. However, the FabR negative regulator was recently shown to represses fabA transcription. We report that the weak promoter overlaps the FadR-dependent promoter and is regulated by FabR. This promoter is strictly conserved in all E. coli and Salmonella enterica genomes sequenced to date and is thought to provide insurance against inappropriate regulation of fabA transcription by exogenous saturated fatty acids. Also, the fabAup promoter, a mutant promoter previously isolated by selection for increased FabA activity, was shown to be a promoter created de novo by a four-base deletion within the gene located immediately upstream of fabA. Demonstration of the key UFA synthetic reaction catalyzed by FabB has been elusive, although it was known to catalyze an elongation reaction. Strains lacking FabB are UFA auxotrophs indicating that the enzyme catalyzes an essential step in UFA synthesis. Using thioesterases specific for hydrolysis of short chain acyl-ACPs, the intermediates of the UFA synthetic pathway have been followed in vivo for the first time. These experiments showed that a fabB mutant strain accumulated less cis-5-dodecenoic acid than the parental wild-type strain. These data indicate that the key reaction in UFA synthesis catalyzed by FabB is elongation of the cis-3-decenoyl-ACP produced by FabA. PMID:19679654

  5. Mono and diterpene production in Escherichia coli.

    PubMed

    Reiling, K Kinkead; Yoshikuni, Yasuo; Martin, Vincent J J; Newman, Jack; Bohlmann, Jörg; Keasling, Jay D

    2004-07-20

    Mono- and diterpenoids are of great industrial and medical value as specialty chemicals and pharmaceuticals. Production of these compounds in microbial hosts, such as Escherichia coli, can be limited by intracellular levels of the polyprenyl diphosphate precursors, geranyl diphosphate (GPP), and geranylgeranyl diphosphate (GGPP). To alleviate this limitation, we constructed synthetic operons that express three key enzymes for biosynthesis of these precursors: (1). DXS,1-deoxy-d-xylulose-5-phosphate synthase; (2). IPPHp, IPP isomerase from Haematococcus pluvialis; and (3). one of two variants of IspA, FPP synthase that produces either GPP or GGPP. The reporter plasmids pAC-LYC and pACYC-IB, which encode enzymes that convert either FPP or GGPP, respectively, to the pigment lycopene, were used to demonstrate that at full induction, the operon encoding the wild-type FPP synthase and mutant GGPP synthase produced similar levels of lycopene. To synthesize di- or monoterpenes in E. coli using the GGPP and GPP encoding operons either a diterpene cyclase [casbene cyclase (Ricinus communis L) and ent-kaurene cyclase (Phaeosphaeria sp. L487)] or a monoterpene cyclase [3-carene cyclase (Picea abies)] was coexpressed with their respective precursor production operon. Analysis of culture extracts or headspace by gas chromatography-mass spectrometry confirmed the in vivo production of the diterpenes casbene, kaur-15-ene, and kaur-16-ene and the monoterpenes alpha-pinene, myrcene, sabinene, 3-carene, alpha-terpinene, limonene, beta-phellandrene, alpha-terpinene, and terpinolene. Construction and functional expression of GGPP and GPP operons provides an in vivo precursor platform host for the future engineering of di- and monoterpene cyclases and the overproduction of terpenes in bacteria.

  6. Microdiesel: Escherichia coli engineered for fuel production.

    PubMed

    Kalscheuer, Rainer; Stölting, Torsten; Steinbüchel, Alexander

    2006-09-01

    Biodiesel is an alternative energy source and a substitute for petroleum-based diesel fuel. It is produced from renewable biomass by transesterification of triacylglycerols from plant oils, yielding monoalkyl esters of long-chain fatty acids with short-chain alcohols such as fatty acid methyl esters and fatty acid ethyl esters (FAEEs). Despite numerous environmental benefits, a broader use of biodiesel is hampered by the extensive acreage required for sufficient production of oilseed crops. Therefore, processes are urgently needed to enable biodiesel production from more readily available bulk plant materials like sugars or cellulose. Toward this goal, the authors established biosynthesis of biodiesel-adequate FAEEs, referred to as Microdiesel, in metabolically engineered Escherichia coli. This was achieved by heterologous expression in E. coli of the Zymomonas mobilis pyruvate decarboxylase and alcohol dehydrogenase and the unspecific acyltransferase from Acinetobacter baylyi strain ADP1. By this approach, ethanol formation was combined with subsequent esterification of the ethanol with the acyl moieties of coenzyme A thioesters of fatty acids if the cells were cultivated under aerobic conditions in the presence of glucose and oleic acid. Ethyl oleate was the major constituent of these FAEEs, with minor amounts of ethyl palmitate and ethyl palmitoleate. FAEE concentrations of 1.28 g l(-1) and a FAEE content of the cells of 26 % of the cellular dry mass were achieved by fed-batch fermentation using renewable carbon sources. This novel approach might pave the way for industrial production of biodiesel equivalents from renewable resources by employing engineered micro-organisms, enabling a broader use of biodiesel-like fuels in the future.

  7. The Escherichia coli Peripheral Inner Membrane Proteome*

    PubMed Central

    Papanastasiou, Malvina; Orfanoudaki, Georgia; Koukaki, Marina; Kountourakis, Nikos; Sardis, Marios Frantzeskos; Aivaliotis, Michalis; Karamanou, Spyridoula; Economou, Anastassios

    2013-01-01

    Biological membranes are essential for cell viability. Their functional characteristics strongly depend on their protein content, which consists of transmembrane (integral) and peripherally associated membrane proteins. Both integral and peripheral inner membrane proteins mediate a plethora of biological processes. Whereas transmembrane proteins have characteristic hydrophobic stretches and can be predicted using bioinformatics approaches, peripheral inner membrane proteins are hydrophilic, exist in equilibria with soluble pools, and carry no discernible membrane targeting signals. We experimentally determined the cytoplasmic peripheral inner membrane proteome of the model organism Escherichia coli using a multidisciplinary approach. Initially, we extensively re-annotated the theoretical proteome regarding subcellular localization using literature searches, manual curation, and multi-combinatorial bioinformatics searches of the available databases. Next we used sequential biochemical fractionations coupled to direct identification of individual proteins and protein complexes using high resolution mass spectrometry. We determined that the proposed cytoplasmic peripheral inner membrane proteome occupies a previously unsuspected ∼19% of the basic E. coli BL21(DE3) proteome, and the detected peripheral inner membrane proteome occupies ∼25% of the estimated expressed proteome of this cell grown in LB medium to mid-log phase. This value might increase when fleeting interactions, not studied here, are taken into account. Several proteins previously regarded as exclusively cytoplasmic bind membranes avidly. Many of these proteins are organized in functional or/and structural oligomeric complexes that bind to the membrane with multiple interactions. Identified proteins cover the full spectrum of biological activities, and more than half of them are essential. Our data suggest that the cytoplasmic proteome displays remarkably dynamic and extensive communication with

  8. Slugs: Potential Novel Vectors of Escherichia coli O157

    PubMed Central

    Sproston, Emma L.; Macrae, M.; Ogden, Iain D.; Wilson, Michael J.; Strachan, Norval J. C.

    2006-01-01

    Field and laboratory studies were performed to determine whether slugs could act as novel vectors for pathogen (e.g., Escherichia coli O157) transfer from animal feces to salad vegetables. Escherichia coli O157 was isolated from 0.21% of field slugs from an Aberdeenshire sheep farm. These isolates carried the verocytotoxin genes (vt1 and vt2) and the attaching and effacing gene (eae), suggesting that they are potentially pathogenic to humans. Strain typing using multilocus variable number tandem repeats analysis showed that slug and sheep isolates were indistinguishable. Laboratory experiments using an E. coli mutant resistant to nalidixic acid showed that the ubiquitous slug species Deroceras reticulatum could carry viable E. coli on its external surface for up to 14 days. Slugs that had been fed E. coli shed viable bacteria in their feces with numbers showing a short but statistically significant linear log decline. Further, it was found that E. coli persisted for up to 3 weeks in excreted slug feces, and hence, we conclude that slugs have the potential to act as novel vectors of E. coli O157. PMID:16391036

  9. Advances in molecular serotyping and subtyping of Escherichia coli

    DOE PAGES

    Fratamico, Pina M.; DebRoy, Chitrita; Liu, Yanhong; ...

    2016-05-03

    Escherichia coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera against the ca. 186 O-antigens and 53 H-flagellar antigens. Phenotypic methods, including bacteriophage typing and O- and H- serotyping for differentiating and characterizing E. coli have been used for many years; however, these methods are generally time consuming and not always accurate. Advances in next generation sequencing technologies have made it possible to develop genetic-based subtypingmore » and molecular serotyping methods for E. coli, which are more discriminatory compared to phenotypic typing methods. Furthermore, whole genome sequencing (WGS) of E. coli is replacing established subtyping methods such as pulsedfield gel electrophoresis, providing a major advancement in the ability to investigate food-borne disease outbreaks and for trace-back to sources. Furthermore, a variety of sequence analysis tools and bioinformatic pipelines are being developed to analyze the vast amount of data generated by WGS and to obtain specific information such as O- and H-group determination and the presence of virulence genes and other genetic markers.« less

  10. Gentamicin resistance among Escherichia coli strains isolated in neonatal sepsis.

    PubMed

    Hasvold, J; Bradford, L; Nelson, C; Harrison, C; Attar, M; Stillwell, T

    2013-01-01

    Neonatal sepsis is a significant cause of morbidity and mortality among term and preterm infants. Ampicillin and gentamicin are standard empiric therapy for early onset sepsis. Four cases of neonatal sepsis secondary to Escherichia coli (E. coli) found to be gentamicin resistant occurred within a five week period in one neonatal intensive care unit (NICU). To determine whether these cases could be tied to a single vector of transmission, and to more broadly evaluate the incidence of gentamicin resistant strains of E. coli in the neonatal population at our institution compared to other centers, we reviewed the charts of the four neonates (Infants A through D) and their mothers. The E. coli isolates were sent for Pulse Field Gel Electrophoresis (PFGE) to evaluate for genetic similarity between strains. We also reviewed all positive E. coli cultures from one NICU over a two year period. Infants A and B had genetically indistinguishable strains which matched that of urine and placental cultures of Infant B's mother. Infant C had a genetically distinct organism. Infant D, the identical twin of Infant C, did not have typing performed. Review of all cultures positive for E. coli at our institution showed a 12.9 percent incidence of gentamicin-resistance. A review of other studies showed that rates of resistance vary considerably by institution. We conclude that gentamicin-resistant E. coli is a relatively uncommon cause of neonatal sepsis, but should remain a consideration in patients who deteriorate despite initiation of empiric antibiotics.

  11. Inactivation of Escherichia coli using atmospheric-pressure plasma jet

    NASA Astrophysics Data System (ADS)

    Kuwahata, Hiroshi; Yamaguchi, Takeshi; Ohyama, Ryu-ichiro; Ito, Atsushi

    2015-01-01

    An atmospheric-pressure argon (Ar) plasma jet was applied to the inactivation of Escherichia coli. The Ar plasma jet was generated at a frequency of 10 kHz, an applied voltage of 10 kV, and an Ar gas flow rate of 10 L/min at atmospheric pressure. E. coli cells seeded on an agar medium in a Petri dish were inactivated by Ar plasma jet irradiation for 1 s. Scanning electron microscopy (SEM) revealed that E. coli cells were killed because their cell wall and membrane were disrupted. To determine the causes of the disruption of the cell wall and membrane of E. coli, we performed the following experiments: the measurement of the surface temperature of an agar medium using a thermograph, the analysis of an emission spectrum of a plasma jet obtained using a multichannel spectrometer, and the determination of the distribution of the concentration of hydrogen peroxide (H2O2) generated on an agar medium by plasma jet irradiation using semiquantitative test strips. Moreover, H2O2 solutions of different concentrations were dropped onto an agar medium seeded with E. coli cells to examine the contribution of H2O2 to the death of E. coli. The results of these experiments showed that the cell wall and membrane of E. coli were disrupted by electrons in the plasma jet, as well as by electroneutral excited nitrogen molecules (N2) and hydroxyl (OH) radicals in the periphery of the plasma jet.

  12. ESBL-producing E. coli in Austrian sewage sludge.

    PubMed

    Reinthaler, Franz Ferdinand; Feierl, Gebhard; Galler, Herbert; Haas, Doris; Leitner, Eva; Mascher, Franz; Melkes, Angelika; Posch, Josefa; Winter, Ingrid; Zarfel, Gernot; Marth, Egon

    2010-03-01

    The aim of this study was to investigate the degree of contamination of sewage sludge with ESBL-producing Escherichia coli strains and the effectiveness of different sewage sludge treatment methods. Monthly sewage sludge samples were collected between January and September 2009 in 5 different sewage treatment plants and tested for the presence of ESBL E. coli. In addition, the number of colony forming units (CFU) of E. coli and coliform bacteria before and after the different sludge treatment methods (aerobic/anaerobic digestion, lime stabilization, and thermal treatment) was investigated. Of the 72 sewage sludge samples investigated, ESBL-positive E. coli were found in 44 (61.1%) sewage sludge samples. The classification of beta-lactamase groups was carried out in 15 strains resulting in the detection of 2 different groups (CTX-M and TEM) of bla genes. All 15 of them had a CTX-M gene and 4 of these strains furthermore carried a TEM gene. With regard to the CFU of E. coli and coliform bacteria, thermal treatment and lime stabilization following dehydration sufficiently reduced pathogen concentrations. The plants using merely stabilization and dehydration showed an increase of E. coli and coliform bacteria and thus also an increase in ESBL-producing E. coli.

  13. Soil solarization reduces Escherichia coli O157:H7 and total Escherichia coli on cattle feedlot pen surfaces.

    PubMed

    Berry, Elaine D; Wells, James E

    2012-01-01

    Feedlot pen soil is a source for transmission of Escherichia coli O157:H7, and therefore a target for preharvest strategies to reduce this pathogen in cattle. The objective of this study was to determine the ability of soil solarization to reduce E. coli O157:H7 in feedlot surface material (FSM). A feedlot pen was identified in which naturally occurring E. coli O157:H7 was prevalent and evenly distributed in the FSM. Forty plots 3 by 3 m were randomly assigned such that five plots of each of the solarization times of 0, 1, 2, 3, 4, 6, 8, and 10 weeks were examined. Temperature loggers were placed 7.5 cm below the surface of each plot, and plots to be solarized were covered with clear 6-mil polyethylene. At each sampling time, five FSM samples were collected from each of five solarized and five unsolarized plots. E. coli concentrations and E. coli O157:H7 presence by immunomagnetic separation and plating were determined for each FSM sample. Initial percentages of E. coli O157:H7-positive samples in control and solarized FSM were 84 and 80%, respectively, and did not differ (P > 0.05). E. coli O157:H7 was no longer detectable by 8 weeks of solarization, but was still detected in unsolarized FSM at 10 weeks. The average initial concentration of E. coli in FSM was 5.56 log CFU/g and did not differ between treatments (P > 0.05). There was a 2.0-log decrease of E. coli after 1 week of solarization, and a >3.0-log reduction of E. coli by week 6 of solarization (P, 0.05). E. coli levels remained unchanged in unsolarized FSM (P > 0.05). Daily peak FSM temperatures were on average 8.7°C higher for solarized FSM compared with unsolarized FSM, and reached temperatures as high as 57°C. Because soil solarization reduces E. coli O157:H7, this technique may be useful for reduction of persistence and transmission of this pathogen in cattle production, in addition to remediation of E. coli O157:H7-contaminated soil used to grow food crops.

  14. Fluorogenic assays for immediate confirmation of Escherichia coli.

    PubMed Central

    Feng, P C; Hartman, P A

    1982-01-01

    Rapid assays for Escherichia coli were developed by using the compound 4-methylumbelliferone glucuronide (MUG), which is hydrolyzed by glucuronidase to yield a fluorogenic product. The production of glucuronidase was limited to strains of E. coli and some Salmonella and Shigella strains in the family Enterobacteriaceae. For immediate confirmation of the presence of E. coli in most-probable-number tubes, MUG was incorporated into lauryl tryptose broth at a final concentration of 100 micrograms/ml. Results of both the presumptive test (gas production) and the confirmed test (fluorescence) for E. coli were obtained from a variety of food, water, and milk samples after incubation for only 24 h at 35 degrees C. Approximately 90% of the tubes showing both gas production and fluorescence contained fecal coliforms (they were positive in EC broth incubated at 45 degrees C). Few false-positive reactions were observed. The lauryl tryptose broth-MUG-most-probable-number assay was superior to violet red bile agar for the detection of heat- and chlorine-injured E. coli cells. Anaerogenic strains produced positive reactions, and small numbers of E. coli could be detected in the presence of large numbers of competing bacteria. The fluorogenic assay was sensitive and rapid; the presence of one viable cell was detected within 20 h. E. coli colonies could be distinguished from other coliforms on membrane filters and plates of violet red bile agar if MUG was incorporated into the culture media. A rapid confirmatory test for E. coli that is amenable to automation was developed by using microtitration plates filled with a nonselective medium containing MUG. Pure or mixed cultures containing E. coli produced fluorescence within 4 h (most strains) to 24 h (a few weakly positive strains). Images PMID:7049088

  15. Prevalence of Escherichia coli in apple cider manufactured in Connecticut.

    PubMed

    Dingman, D W

    1999-06-01

    Cider samples obtained from 11 cider mills operating in Connecticut during the 1997 to 1998 production season were tested for the presence of Escherichia coli. Cider production began in mid August and continued through March, with peak production in September and October. Of 314 cider samples tested, 11 (4%) were found to contain E. coli. Of the 11 mills, 6 (55%) tested positive for E. coli in the cider at least once during the production year. E. coli was first observed in cider samples produced in mid to late October and was not detected in samples made after January. A trend was observed for cider to decrease in acidity and increase in Brix (soluble sugars) throughout the production season. No correlation between pH and soluble sugars of cider and the presence of E. coli was detected. Eight mills used both dropped apples and tree-picked apples, whereas three mills used tree-picked apples only. The use of dropped apples in cider production began 5 weeks before the first detection of E. coli in cider. E. coli was isolated from cider samples produced using dropped apples and from samples produced using only tree-picked apples. No direct correlation between the use of dropped apples or tree-picked apples and the presence of E. coli in the cider was observed. An association between the time of apple harvest and the appearance of E. coli in cider was noted. For mills providing adequate records, all contaminated cider was produced from apples harvested between mid October and mid November.

  16. Thymineless Death in Escherichia coli: Inactivation and Recovery

    PubMed Central

    Cummings, Donald J.; Kusy, Alvin R.

    1969-01-01

    The effects of chloramphenicol (CAP) on the progress of thymineless death (TLD), nalidixic acid (NA) inactivation, ultraviolet (UV) irradiation, and mitomycin C (MC) inactivation were studied in Escherichia coli B, Bs−1, Bs−3, Bs−12, and B/r. This was done before, during, and after inactivation. During the progress of inactivation, it was found that at 10 to 20 μg of CAP per ml, up to 50% of the UV-sensitive bacteria survived TLD and about 10% survived NA. In E. coli B/r, at these concentrations of CAP, about 10 to 15% of the cells survived TLD and about 20 to 25% survived NA. Concentrations of CAP greater than 25 μg/ml actually increased the sensitivity of E. coli B, Bs−1, Bs−3, and Bs−12 to inactivation by either TLD or NA; at 150 μg of CAP per ml, the sensitivity of E. coli B/r to inactivation also increased. When E. coli B cells were incubated in CAP prior to inactivation, the longer the preincubation the longer onset of TLD was delayed; NA inactivation was also affected in that the rate of inactivation after CAP incubation was greatly decreased. Preincubation of E. coli B/r with CAP had much less effect on the progress of inactivation. After thymineless death, incubation in CAP plus thymine led to a rapid and almost complete recovery of E. coli B and Bs−12. Lesser recoveries were observed after inactivation due to UV, NA, or MC inactivation. E. coli Bs−1 and B/r did not recover viability after any mode of inactivation, and E. coli Bs−3 and Bs−12 recovered from UV to about 20% of the initial titer. It was suggested that protein synthesis, in particular proteins involved in deoxyribonucleic synthesis, was a determining factor in these inactivating and recovery events. PMID:4897115

  17. Triglyceride kinetics in fasted and fed E. coli septic rats

    SciTech Connect

    Lanza-Jacoby, S.; Tabares, A. )

    1990-02-26

    The mechanism for the development of hypertriglyceridemia during gram-negative sepsis was studies by examining the liver production and clearance of very-low-density lipoprotein (VLDL) triglyceride (TG). To assess the liver output and peripheral clearance the kinetics of VLDL-TG were determined by a constant intravenous infusion of (2-{sup 3}H) glycerol-labeled VLDL in fasted control, fasted E. coli-treated, fed control, and fed E.coli-treated rats. Lewis inbred rats, 275-300 g, were made septic with 8 {times} 10{sup 7} live E.coli colonies per 100 g body weight. Twenty-four hours following E.coli injection serum TG of fasted E.coli-treated rats was elevated by 170% which was attributed to a 67% decrease in the clearance rate of VLDL-TG in fasted E.coli-treated rats compared with their fasted controls. The secretion of VLDL-TG declined by 31% in the livers of the fasted E.coli-treated rats which was accompanied by a 2-fold increase in the composition of liver TG. In a second series of experiments control and E.coli-treated rats were fed intragastrically (IG) a balanced solution containing glucose plus fat as the sources of nonprotein calories. Serum TG were 26% lower in the fed E.coli-treated rats because the clearance rate increased by 86%. The secretion of TG in the fed septic rats increased by 40% but this difference was not significant. In the septic rat the ability to clear triglycerides from the plasma depends upon the nutritional state.

  18. The quantitative and condition-dependent Escherichia coli proteome

    PubMed Central

    Schmidt, Alexander; Kochanowski, Karl; Vedelaar, Silke; Ahrné, Erik; Volkmer, Benjamin; Callipo, Luciano; Knoops, Kèvin; Bauer, Manuel; Aebersold, Ruedi; Heinemann, Matthias

    2016-01-01

    Measuring precise concentrations of proteins can provide insights into biological processes. Here, we use efficient protein extraction and sample fractionation and state-of-the-art quantitative mass spectrometry techniques to generate a comprehensive, condition-dependent protein abundance map of Escherichia coli. We measure cellular protein concentrations for 55% of predicted E. coli genes (>2300 proteins) under 22 different experimental conditions and identify methylation and N-terminal protein acetylations previously not known to be prevalent in bacteria. We uncover system-wide proteome allocation, expression regulation, and post-translational adaptations. These data provide a valuable resource for the systems biology and broader E. coli research communities. PMID:26641532

  19. An integrated database to support research on Escherichia coli

    SciTech Connect

    Baehr, A.; Dunham, G.; Matsuda, Hideo; Michaels, G.; Taylor, R.; Overbeek, R.; Rudd, K.E.; Ginsburg, A.; Joerg, D.; Kazic, T.; Hagstrom, R.; Zawada, D.; Smith, C.; Yoshida, Kaoru

    1992-01-01

    We have used logic programming to design and implement a prototype database of genomic information for the model bacterial organism Escherichia coli. This report presents the fundamental database primitives that can be used to access and manipulate data relating to the E. coli genome. The present system, combined with a tutorial manual, provides immediate access to the integrated knowledge base for E. coli chromosome data. It also serves as the foundation for development of more user-friendly interfaces that have the same retrieval power and high-level tools to analyze complex chromosome organization.

  20. YeeO from Escherichia coli exports flavins.

    PubMed

    McAnulty, Michael J; Wood, Thomas K

    2014-01-01

    Multidrug and toxic compound extrusion (MATE) proteins help maintain cellular homeostasis by secreting metabolic wastes. Flavins may occur as cellular waste products, with their production and secretion providing potential benefit for industrial applications related to biofuel cells. Here we find that MATE protein YeeO from Escherichia coli exports both flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Significant amounts of flavins were trapped intracellularly when YeeO was produced indicating transport limits secretion of flavins. Wild-type E. coli secreted 3 flavins (riboflavin, FMN, and FAD), so E. coli likely produces additional flavin transporters.

  1. Production of Enzymatically Active Human Acetylcholinesterase in E. Coli

    DTIC Science & Technology

    1993-10-01

    AD-A282 703 lE1l1lm11I AD( CONTRACT NO: DAMD17-90-C-0107 TITLE: PRODUCTION OF ENZYMATICALLY ACTIVE HUMAN ACETYLCHOLINESTERASE IN E . COLI PRINCIPAL...FUNDING NUMBERS Production of Enzymatically Active Human Contract No. Acetylcholinesterase in E . coli DAMD17-90-C-0107 6. AUTHOR(S) M. Gorecki, Ph.D. and M...S493pMFL-52Ser - Run #1 37 Table 8: Summary of reconstitution and purification of rhAChE derived from E . coli S493pMFL-52Ser - Run #2 38 Table 9

  2. Heat-stable Escherichia coli enterotoxin production in vivo.

    PubMed Central

    Whipp, S C; Moon, H W; Lyon, N C

    1975-01-01

    Hysterectomy-derived, colostrum-deprived piglets were infected with enterotoxigenic Escherichia coli on day 4 of life. Samples of feces and intestinal contents were collected and tested in infant mice for enterotoxic activity. Positive enterotoxic responses were observed in mice given filtrates of feces and intestinal contents from piglets infected withe enterotoxigenic E. coli known to produce heat-stable enterotoxin but not heat-liabile enterotoxin in vitro. It is concluded that heat-stable enterotoxigenic E. coli induce diarrhea by production of heat-stable enterotoxin in vivo. PMID:1097335

  3. Reassessing Escherichia coli as a cell factory for biofuel production.

    PubMed

    Wang, Chonglong; Pfleger, Brian F; Kim, Seon-Won

    2017-03-11

    Via metabolic engineering, industrial microorganisms have the potential to convert renewable substrates into a wide range of biofuels that can address energy security and environmental challenges associated with current fossil fuels. The user-friendly bacterium, Escherichia coli, remains one of the most frequently used hosts for demonstrating production of biofuel candidates including alcohol-, fatty acid- and terpenoid-based biofuels. In this review, we summarize the metabolic pathways for synthesis of these biofuels and assess enabling technologies that assist in regulating biofuel synthesis pathways and rapidly assembling novel E. coli strains. These advances maintain E. coli's position as a prominent host for developing cell factories for biofuel production.

  4. Enteropathogenic Escherichia coli Serotypes and Endemic Diarrhea in Infants

    PubMed Central

    Toledo, M. Regina F.; Alvariza, M. do Carmo B.; Murahovschi, Jayme; Ramos, Sonia R. T. S.; Trabulsi, Luiz R.

    1983-01-01

    Enteropathogenic Escherichia coli serotypes were searched for in feces of 550 children with endemic diarrhea and in 129 controls, in São Paulo, in 1978 and 1979; serotypes O111ab:H−, O111ab:H2, and O119:H6 were significantly associated with diarrhea in children 0 to 5 months old and were the most frequent agents of diarrhea in this age group as compared with enterotoxigenic and enteroinvasive E. coli, Salmonella sp., Shigella sp., and Yersinia enterocolitica. It is concluded that various enteropathogenic E. coli serotypes may be agents of endemic infantile diarrhea. PMID:6339384

  5. Prevalence and behavior of multidrug-resistant shiga toxin-producing Escherichia coli, enteropathogenic E. coli and enterotoxigenic E. coli on coriander.

    PubMed

    Gómez-Aldapa, Carlos A; Segovia-Cruz, Jesús A; Cerna-Cortes, Jorge F; Rangel-Vargas, Esmeralda; Salas-Rangel, Laura P; Gutiérrez-Alcántara, Eduardo J; Castro-Rosas, Javier

    2016-10-01

    The prevalence and behavior of multidrug-resistant diarrheagenic Escherichia coli pathotypes on coriander was determined. One hundred coriander samples were collected from markets. Generic E. coli were determined using the most probable number procedure. Diarrheagenic E. coli pathotypes (DEPs) were identified using two multiplex polymerase chain reaction procedures. Susceptibility to sixteen antibiotics was tested for the isolated DEPs strains by standard test. The behavior of multidrug-resistant DEPs isolated from coriander was determined on coriander leaves and chopped coriander at 25°± 2 °C and 3°± 2 °C. Generic E. coli and DEPs were identified, respectively, in 43 and 7% of samples. Nine DEPs strains were isolated from positive coriander samples. The identified DEPs included Shiga toxin-producing E. coli (STEC, 4%) enterotoxigenic E. coli (ETEC, 2%) and enteropathogenic E. coli (EPEC, 1%). All isolated DEPs strains exhibited multi-resistance to antibiotics. On inoculated coriander leaves stored at 25°± 2 °C or 3°± 2 °C, no growth was observed for multidrug-resistant DEPs strains. However, multidrug-resistant DEPs strains grew in chopped coriander: after 24 h at 25° ± 2 °C, DEPs strains had grown to approximately 3 log CFU/g. However, at 3°± 2 °C the bacterial growth was inhibited. To the best of our knowledge, this is the first report of the presence and behavior of multidrug-resistant STEC, ETEC and EPEC on coriander and chopped coriander.

  6. Diarrhea, Urosepsis and Hemolytic Uremic Syndrome Caused by the Same Heteropathogenic Escherichia coli Strain.

    PubMed

    Ang, C Wim; Bouts, Antonia H M; Rossen, John W A; Van der Kuip, Martijn; Van Heerde, Marc; Bökenkamp, Arend

    2016-09-01

    We describe an 8-month-old girl with diarrhea, urosepsis and hemolytic uremic syndrome caused by Escherichia coli. Typing of cultured E. coli strains from urine and blood revealed the presence of virulence factors from multiple pathotypes of E. coli. This case exemplifies the genome plasticity of E. coli and the resulting heteropathogenic strains.

  7. Genome Sequence of the Enterohemorrhagic Escherichia coli Bacteriophage UFV-AREG1.

    PubMed

    Lopez, Maryoris E Soto; Batalha, Laís Silva; Vidigal, Pedro Marcus Pereira; Albino, Luiz Augusto A; Boggione, Delaine Meireles Gouveia; Gontijo, Marco Tulio Pardini; Bazzolli, Denise M Soares; Mendonca, Regina C Santos

    2016-10-13

    Here, we present the genome sequence of the Escherichia coli bacteriophage UFV-AREG1. This phage was isolated from cowshed wastewater and showed specificity for enterohemorrhagic E. coli O157:H7 (ATCC 43895), E. coli 0111 (CDC O11ab) and E. coli (ATCC 23229).

  8. Genome Sequence of the Enterohemorrhagic Escherichia coli Bacteriophage UFV-AREG1

    PubMed Central

    Batalha, Laís Silva; Albino, Luiz Augusto A.; Boggione, Delaine Meireles Gouveia; Gontijo, Marco Tulio Pardini; Bazzolli, Denise M. Soares; Mendonca, Regina C. Santos

    2016-01-01

    Here, we present the genome sequence of the Escherichia coli bacteriophage UFV-AREG1. This phage was isolated from cowshed wastewater and showed specificity for enterohemorrhagic E. coli O157:H7 (ATCC 43895), E. coli 0111 (CDC O11ab) and E. coli (ATCC 23229). PMID:27738021

  9. Molecular characterization of diarrheagenic Escherichia coli strains from stools samples and food products in Colombia

    PubMed Central

    Rúgeles, Laura Cristina; Bai, Jing; Martínez, Aída Juliana; Vanegas, María Consuelo; Gómez-Duarte, Oscar Gilberto

    2010-01-01

    The prevalence of diarrheagenic E. coli in childhood diarrhea and the role of contaminated food products in disease transmission in Colombia are largely unknown. The aim of this study is to identify E. coli pathotypes, including E. coli O157:H7, from 108 stool samples from children with acute diarrhea, 38 meat samples and 38 vegetable samples. Multiplex PCR and Bax Dupont systems were used for E. coli pathotype detection. Eighteen (9.8%) E. coli diarrheagenic pathotypes were detected among all clinical and food product samples tested. Four different pathotypes were identified from clinical samples, including enteroaggregative E. coli, enterotoxigenic E. coli, shiga-toxin producing E. coli, and enteropathogenic E. coli. Food product samples were positive for enteroaggregative and shiga-toxin producing E. coli, suggesting that meat and vegetables may be involved in transmission of these E. coli pathotypes in the community. Most E. coli strains identified belong to the phylogenetic groups A and B1, known to be associated with intestinal rather than extraintestinal E. coli clones. Our data is the first molecular E. coli report that confirms the presence of E. coli pathotypes circulating in Colombia among children with diarrhea and food products for human consumption. Implementation of multiplex PCR technology in Latin America and other countries with limited resources may provide an important epidemiological tool for the surveillance of E. coli pathotypes from clinical isolates as well as from water and food product samples. PMID:20153069

  10. Molecular characterization of diarrheagenic Escherichia coli strains from stools samples and food products in Colombia.

    PubMed

    Rúgeles, Laura Cristina; Bai, Jing; Martínez, Aída Juliana; Vanegas, María Consuelo; Gómez-Duarte, Oscar Gilberto

    2010-04-15

    The prevalence of diarrheagenic Escherichia coli in childhood diarrhea and the role of contaminated food products in disease transmission in Colombia are largely unknown. The aim of this study is to identify E. coli pathotypes, including E. coli O157:H7, from 108 stool samples from children with acute diarrhea, 38 meat samples and 38 vegetable samples. Multiplex PCR and Bax Dupont systems were used for E. coli pathotype detection. Eighteen (9.8%) E. coli diarrheagenic pathotypes were detected among all clinical and food product samples tested. Four different pathotypes were identified from clinical samples, including enteroaggregative E. coli, enterotoxigenic E. coli, shiga-toxin producing E. coli, and enteropathogenic E. coli. Food product samples were positive for enteroaggregative and shiga-toxin producing E. coli, suggesting that meat and vegetables may be involved in transmission of these E. coli pathotypes in the community. Most E. coli strains identified belong to the phylogenetic groups A and B1, known to be associated with intestinal rather than extraintestinal E. coli clones. Our data is the first molecular E. coli report that confirms the presence of E. coli pathotypes circulating in Colombia among children with diarrhea and food products for human consumption. Implementation of multiplex PCR technology in Latin America and other countries with limited resources may provide an important epidemiological tool for the surveillance of E. coli pathotypes from clinical isolates as well as from water and food product samples.

  11. 75 FR 14607 - Small Entity Compliance Guide: Bottled Water: Total Coliform and E. coli

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-26

    ... are Escherichia coli (E. coli), an indicator of fecal contamination. FDA also amended its bottled... and E. coli; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food... ``Bottled Water: Total Coliform and E. coli--Small Entity Compliance Guide'' for a final rule published...

  12. 40 CFR 141.858 - Repeat monitoring and E. coli requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... exceeded. (b) Escherichia coli (E. coli) testing. (1) If any routine or repeat sample is total coliform... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Repeat monitoring and E. coli....858 Repeat monitoring and E. coli requirements. (a) Repeat monitoring. (1) If a sample taken...

  13. 40 CFR 141.858 - Repeat monitoring and E. coli requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... exceeded. (b) Escherichia coli (E. coli) testing. (1) If any routine or repeat sample is total coliform... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Repeat monitoring and E. coli....858 Repeat monitoring and E. coli requirements. (a) Repeat monitoring. (1) If a sample taken...

  14. Multiplex PCR for Diagnosis of Enteric Infections Associated with Diarrheagenic Escherichia coli

    PubMed Central

    Vidal, Roberto; Vidal, Maricel; Lagos, Rossana; Levine, Myron; Prado, Valeria

    2004-01-01

    A multiplex PCR for detection of three categories of diarrheagenic Escherichia coli was developed. With this method, enterohemorrhagic E. coli, enteropathogenic E. coli, and enterotoxigenic E. coli were identified in fecal samples from patients with hemorrhagic colitis, watery diarrhea, or hemolytic-uremic syndrome and from food-borne outbreaks. PMID:15071051

  15. Characterization of a novel hemagglutinin of diarrhea-associated Escherichia coli that has characteristics of diffusely adhering E. coli and enteroaggregative E. coli.

    PubMed Central

    Yamamoto, T; Wakisaka, N; Nakae, T; Kamano, T; Serichantalergs, O; Echeverria, P

    1996-01-01

    Escherichia coli 73-1 (serotype O73:H33) and 5-2 (serotype O89:H-) isolated from patients with diarrhea adhered to tissue culture cells (HeLa and HEp-2) as well as coverslips (plastic and glass) in a diffuse pattern. Adherence of strain 73-1 was mediated by a 110-kbp plasmid designated pEDA1 and correlated with D-mannose-resistant hemagglutinin (MRHA) detected with bovine, sheep, or human erythrocytes. The MRHA region was duplicated on pEDA1 and mediated the production of the 57-kDa outer membrane protein whose N-terminal amino acid sequence was hydrophobic. In accordance with MRHA and adherence, the 57-kDa outer membrane protein was observed best at 37 degrees C and to a lesser extent at 25 degrees C. In human intestine, adherence to mucus and colonic epithelium was obvious. No detectable pili were observed. The enteroaggregative E. coli heat-stable enterotoxin 1 (EAST1) gene, whose nucleotide sequence was 99.1% homologous to that of enteroaggregative E. coli, was present adjacent to the MRHA region on pEDA1. Strain 5-2 also exhibited MRHA activities and adherence and had sequences corresponding to those of the MRHA region and EAST1 gene. The data suggest that strain 73-1 (and strain 5-2), which has characteristics of both diffusely adhering E. coli and enteroaggregative E. coli, possesses a novel hemagglutinin associated with diffuse adherence. PMID:8751919

  16. Free RNA polymerase in Escherichia coli.

    PubMed

    Patrick, Michael; Dennis, Patrick P; Ehrenberg, Mans; Bremer, Hans

    2015-12-01

    The frequencies of transcription initiation of regulated and constitutive genes depend on the concentration of free RNA polymerase holoenzyme [Rf] near their promoters. Although RNA polymerase is largely confined to the nucleoid, it is difficult to determine absolute concentrations of [Rf] at particular locations within the nucleoid structure. However, relative concentrations of free RNA polymerase at different growth rates, [Rf]rel, can be estimated from the activities of constitutive promoters. Previous studies indicated that the rrnB P2 promoter is constitutive and that [Rf]rel in the vicinity of rrnB P2 increases with increasing growth rate. Recently it has become possible to directly visualize Rf in growing Escherichia coli cells. Here we examine some of the important issues relating to gene expression based on these new observations. We conclude that: (i) At a growth rate of 2 doublings/h, there are about 1000 free and 2350 non-specifically DNA-bound RNA polymerase molecules per average cell (12 and 28%, respectively, of 8400 total) which are in rapid equilibrium. (ii) The reversibility of the non-specific binding generates more than 1000 free RNA polymerase molecules every second in the immediate vicinity of the DNA. Of these, most rebind non-specifically to the DNA within a few ms; the frequency of non-specific binding is at least two orders of magnitude greater than specific binding and transcript initiation. (iii) At a given amount of RNA polymerase per cell, [Rf] and the density of non-specifically DNA-bound RNA polymerase molecules along the DNA both vary reciprocally with the amount of DNA in the cell. (iv) At 2 doublings/h an E. coli cell contains, on the average, about 1 non-specifically bound RNA polymerase per 9 kbp of DNA and 1 free RNA polymerase per 20 kbp of DNA. However some DNA regions (i.e. near active rRNA operons) may have significantly higher than average [Rf].

  17. TRIMETHOPRIM-SULFAMETHOXAZOLE RESISTANCE IN SEWAGE ISOLATES OF ESCHERICHIA COLI

    EPA Science Inventory

    Sewage samples from seven locations in the United States were analyzed for Escherichia coli isolates which were resistant to trimethoprim-sulfamethoxazole (SXT). The prevalence rate of SXT resistant organisms varied between the different geographical locales. The majority of th...

  18. The different ecological niches of enterotoxigenic E scherichia coli

    PubMed Central

    Gonzales‐Siles, Lucia

    2015-01-01

    Summary Enterotoxigenic E scherichia coli (ETEC) is a water and food‐borne pathogen that infects the small intestine of the human gut and causes diarrhoea. Enterotoxigenic E. coli adheres to the epithelium by means of colonization factors and secretes two enterotoxins, the heat labile toxin and/or the heat stable toxin that both deregulate ion channels and cause secretory diarrhoea. Enterotoxigenic E. coli as all E. coli, is a versatile organism able to survive and grow in different environments. During transmission and infection, ETEC is exposed to various environmental cues that have an impact on survivability and virulence. The ability to cope with exposure to different stressful habitats is probably shaping the pool of virulent ETEC strains that cause both endemic and epidemic infections. This review will focus on the ecology of ETEC in its different habitats and interactions with other organisms as well as abiotic factors. PMID:26522129

  19. Genome Sequence of Escherichia coli Tailed Phage Utah

    PubMed Central

    Leavitt, Justin C.; Heitkamp, Alexandra J.; Bhattacharjee, Ananda S.; Gilcrease, Eddie B.

    2017-01-01

    ABSTRACT Escherichia coli bacteriophage Utah is a member of the chi-like tailed phage cluster in the Siphoviridae family. We report here the complete 59,024-bp sequence of the genome of phage Utah. PMID:28360173

  20. Proton-linked D-xylose transport in Escherichia coli.

    PubMed Central

    Lam, V M; Daruwalla, K R; Henderson, P J; Jones-Mortimer, M C

    1980-01-01

    The addition of xylose to energy-depleted cells of Escherichia coli elicited an alkaline pH change which failed to appear in the presence of uncoupling agents. Accumulation of [14C]xylose by energy-replete cells was also inhibited by uncoupling agents, but not by fluoride or arsenate. Subcellular vesicles of E. coli accumulated [14C]xylose provided that ascorbate plus phenazine methosulfate were present for respiration, and this accumulation was inhibited by uncoupling agents or valinomycin. Therefore, the transport of xylose into E. coli appears to be energized by a proton-motive force, rather than by a phosphotransferase or directly energized mechanism. Its specificity for xylose as inducer and substrate and the genetic location of a xylose-H+ transport-negative mutation near mtl showed that the xylose-H+ system is distinct from other proton-linked sugar transport systems of E. coli. PMID:6995439

  1. Evolution in the Lab: Biocide Resistance in E.coli.

    ERIC Educational Resources Information Center

    Welden, Charles W.; Hossler, Rex A.

    2003-01-01

    Describes a laboratory experiment on resistance to teach about evolution and issues of misuse of antimicrobial compounds. Investigates Escherichia coli's response to treatment of triclosan, a biocide used in consumer products. (Contains 12 references.) (YDS)

  2. A comprehensive library of fluorescent transcriptional reporters for Escherichia coli.

    PubMed

    Zaslaver, Alon; Bren, Anat; Ronen, Michal; Itzkovitz, Shalev; Kikoin, Ilya; Shavit, Seagull; Liebermeister, Wolfram; Surette, Michael G; Alon, Uri

    2006-08-01

    E. coli is widely used for systems biology research; there exists a need, however, for tools that can be used to accurately and comprehensively measure expression dynamics in individual living cells. To address this we present a library of transcriptional fusions of gfp to each of about 2,000 different promoters in E. coli K12, covering the great majority of the promoters in the organism. Each promoter fusion is expressed from a low-copy plasmid. We demonstrate that this library can be used to obtain highly accurate dynamic measurements of promoter activity on a genomic scale, in a glucose-lactose diauxic shift experiment. The library allowed detection of about 80 previously uncharacterized transcription units in E. coli, including putative internal promoters within previously known operons, such as the lac operon. This library can serve as a tool for accurate, high-resolution analysis of transcription networks in living E. coli cells.

  3. Biosynthesis of Two Flavones, Apigenin and Genkwanin, in Escherichia coli.

    PubMed

    Lee, Hyejin; Kim, Bong Gyu; Kim, Mihyang; Ahn, Joong-Hoon

    2015-09-01

    The flavonoid apigenin and its O-methyl derivative, genkwanin, have various biological activities and can be sourced from some vegetables and fruits. Microorganisms are an alternative for the synthesis of flavonoids. Here, to synthesize genkwanin from tyrosine, we first synthesized apigenin from p-coumaric acid using four genes (4CL, CHS, CHI, and FNS) in Escherichia coli. After optimization of different combinations of constructs, the yield of apigenin was increased from 13 mg/l to 30 mg/l. By introducing two additional genes (TAL and POMT7) into an apigenin-producing E. coli strain, we were able to synthesize 7-O-methyl apigenin (genkwanin) from tyrosine. In addition, the tyrosine content in E. coli was modulated by overexpressing aroG and tyrA. The engineered E. coli strain synthesized approximately 41 mg/l genkwanin.

  4. Large Surface Blebs on Escherichia coli Heated to Inactivating Temperatures

    PubMed Central

    Scheie, Paul; Ehrenspeck, Susan

    1973-01-01

    Large surface blebs were observed with phase-contrast optics on Escherichia coli B/r and Bs-1 heated to temperatures at which colony-forming ability was lost. Characterization of such blebs was consistent with the view that they were formed by a physical process and were bounded by the outer membrane of the cell. A hypothesis for thermal inactivation of E. coli is presented that places membrane damage near the primary lethal event. Images PMID:4196258

  5. ENERGY REQUIREMENT FOR THYMINELESS DEATH IN CELLS OF ESCHERICHIA COLI.

    PubMed

    FREIFELDER, D; MAALOE, O

    1964-10-01

    Freifelder, David (University of California, Berkeley), and Ole Maaløe. Energy requirement for thymineless death in cells of Escherichia coli. J. Bacteriol. 88:987-990. 1964.-Thymineless death in thymine-requiring Escherichia coli is arrested immediately and reversibly by nitrogenation if the bacterial population is growing in a medium containing a carbon source that can only be metabolized aerobically. The mechanism of death, therefore, involves a metabolic process.

  6. ENERGY REQUIREMENT FOR THYMINELESS DEATH IN CELLS OF ESCHERICHIA COLI

    PubMed Central

    Freifelder, David; Maaløe, Ole

    1964-01-01

    Freifelder, David (University of California, Berkeley), and Ole Maaløe. Energy requirement for thymineless death in cells of Escherichia coli. J. Bacteriol. 88:987–990. 1964.—Thymineless death in thymine-requiring Escherichia coli is arrested immediately and reversibly by nitrogenation if the bacterial population is growing in a medium containing a carbon source that can only be metabolized aerobically. The mechanism of death, therefore, involves a metabolic process. PMID:14219063

  7. Expression of staphylococcal enterotoxin C1 in Escherichia coli.

    PubMed Central

    Bohach, G A; Schlievert, P M

    1987-01-01

    The structural gene encoding staphylococcal enterotoxin C1 was cloned into Escherichia coli and localized on a 1.5-kilobase HindIII-ClaI DNA fragment by subcloning. The toxin was partially purified from E. coli clones and shown to be immunologically identical to enterotoxin C1 from Staphylococcus aureus. The cloned toxin also had the same molecular weight (26,000) and charge heterogeneity as staphylococcus-derived enterotoxin. Toxins from both sources were equally biologically active. Images PMID:3542834

  8. Construction and expression of recombinant plasmids encoding type 1 fimbriae of a urinary Klebsiella pneumoniae isolate.

    PubMed Central

    Purcell, B K; Clegg, S

    1983-01-01

    The type 1 fimbriae of Klebsiella pneumoniae have been implicated as important virulence factors in mediating Klebsiella urinary infections. The chromosomally encoded fimbrial genes were cloned by a cosmid cloning technique. Further subcloning was performed with the cloning vehicles pBR322 and pACYC184, and a recombinant plasmid containing the fimbrial genes was constructed. After transformation by this plasmid, both Escherichia coli and Salmonella typhimurium were shown to express fimbriae which reacted with Klebsiella fimbrial antiserum. The approximate location of the relevant genes on the chimeric plasmid was determined by insertion of the transposable element Tn5. Hemagglutination-negative phenotypes were used to estimate the minimum size of the DNA fragment necessary to encode fimbrial biosynthesis and expression. The size of the coding region of this fragment was found to be 5.5 kilobase pairs. PMID:6132874

  9. Summer E. coli patterns and responses along 23 Chicago beaches

    USGS Publications Warehouse

    Whitman, R.L.; Nevers, M.B.

    2008-01-01

    Concentrations of E. coli in recreational beach water are highly variable both locally and temporally, but a broader understanding of these fluctuations may be explained through coastal observations. Currently, beach contamination study approaches tend to be site-specific underthe belief that politically delineated beaches are unique and management of beaches cannot be regionally oriented. E. coli data collected over five years from 23 Chicago beaches clearly identified ambient linked patterns at the regional scale. Temporal fluctuations were similar, with all beaches having simultaneous peaks and troughs of E. coli concentrations. Spatially, E. coli concentrations for beaches more closely situated were more closely correlated, indicating spatial autocorrelation. Julian day, wave height, and barometric pressure explained up to 40% of the variation, a value comparable to individual, less parsimonious site-specific models. Day of sampling could explain the majority of the variation in E. coli concentrations, more so than beach, depth, or time of day. Comparing beaches along a targeted coastline allows a better understanding of inherent background regional fluctuations and, ultimately, better predictions of E. coli concentrations in coastal recreational water.

  10. A novel toolbox for E. coli lysis monitoring.

    PubMed

    Rajamanickam, Vignesh; Wurm, David; Slouka, Christoph; Herwig, Christoph; Spadiut, Oliver

    2017-01-01

    The bacterium Escherichia coli is a well-studied recombinant host organism with a plethora of applications in biotechnology. Highly valuable biopharmaceuticals, such as antibody fragments and growth factors, are currently being produced in E. coli. However, the high metabolic burden during recombinant protein production can lead to cell death, consequent lysis, and undesired product loss. Thus, fast and precise analyzers to monitor E. coli bioprocesses and to retrieve key process information, such as the optimal time point of harvest, are needed. However, such reliable monitoring tools are still scarce to date. In this study, we cultivated an E. coli strain producing a recombinant single-chain antibody fragment in the cytoplasm. In bioreactor cultivations, we purposely triggered cell lysis by pH ramps. We developed a novel toolbox using UV chromatograms as fingerprints and chemometric techniques to monitor these lysis events and used flow cytometry (FCM) as reference method to quantify viability offline. Summarizing, we were able to show that a novel toolbox comprising HPLC chromatogram fingerprinting and data science tools allowed the identification of E. coli lysis in a fast and reliable manner. We are convinced that this toolbox will not only facilitate E. coli bioprocess monitoring but will also allow enhanced process control in the future.

  11. Summer E. coli patterns and responses along 23 Chicago beaches.

    PubMed

    Whitman, Richard L; Nevers, Meredith B

    2008-12-15

    Concentrations of E. coli in recreational beach water are highly variable both locally and temporally, but a broader understanding of these fluctuations may be explained through coastal observations. Currently, beach contamination study approaches tend to be site-specific under the belief that politically delineated beaches are unique and management of beaches cannot be regionally oriented. E. coli data collected over five years from 23 Chicago beaches clearly identified ambient linked patterns at the regional scale. Temporal fluctuations were similar, with all beaches having simultaneous peaks and troughs of E. coli concentrations. Spatially, E. coli concentrations for beaches more closely situated were more closely correlated, indicating spatial autocorrelation. Julian day, wave height, and barometric pressure explained up to 40% of the variation, a value comparable to individual, less parsimonious site-specific models. Day of sampling could explain the majority of the variation in E. coli concentrations, more so than beach, depth, or time of day. Comparing beaches along a targeted coastline allows a better understanding of inherent background regional fluctuations and, ultimately, better predictions of E. coli concentrations in coastal recreational water.

  12. Interaction of Escherichia coli and Soil Particles in Runoff

    PubMed Central

    Muirhead, Richard William; Collins, Robert Peter; Bremer, Philip James

    2006-01-01

    A laboratory-scale model system was developed to investigate the transport mechanisms involved in the horizontal movement of bacteria in overland flow across saturated soils. A suspension of Escherichia coli and bromide tracer was added to the model system, and the bromide concentration and number of attached and unattached E. coli cells in the overland flow were measured over time. Analysis of the breakthrough curves indicated that the E. coli and bromide were transported together, presumably by the same mechanism. This implied that the E. coli was transported by advection with the flowing water. Overland-flow transport of E. coli could be significantly reduced if the cells were preattached to large soil particles (>45 μm). However, when unattached cells were inoculated into the system, the E. coli appeared to attach predominantly to small particles (<2 μm) and hence remained unattenuated during transport. These results imply that in runoff generated by saturation-excess conditions, bacteria are rapidly transported across the surface and have little opportunity to interact with the soil matrix. PMID:16672484

  13. Measuring Escherichia coli Gene Expression during Human Urinary Tract Infections

    PubMed Central

    Mobley, Harry L. T.

    2016-01-01

    Extraintestinal Escherichia coli (E. coli) evolved by acquisition of pathogenicity islands, phage, plasmids, and DNA segments by horizontal gene transfer. Strains are heterogeneous but virulent uropathogenic isolates more often have specific fimbriae, toxins, and iron receptors than commensal strains. One may ask whether it is the virulence factors alone that are required to establish infection. While these virulence factors clearly contribute strongly to pathogenesis, bacteria must survive by metabolizing nutrients available to them. By constructing mutants in all major metabolic pathways and co-challenging mice transurethrally with each mutant and the wild type strain, we identified which major metabolic pathways are required to infect the urinary tract. We must also ask what else is E. coli doing in vivo? To answer this question, we examined the transcriptome of E. coli CFT073 in the murine model of urinary tract infection (UTI) as well as for E. coli strains collected and analyzed directly from the urine of patients attending either a urology clinic or a university health clinic for symptoms of UTI. Using microarrays and RNA-seq, we measured in vivo gene expression for these uropathogenic E. coli strains, identifying genes upregulated during murine and human UTI. Our findings allow us to propose a new definition of bacterial virulence. PMID:26784237

  14. Regulation of arabinose and xylose metabolism in Escherichia coli.

    PubMed

    Desai, Tasha A; Rao, Christopher V

    2010-03-01

    Bacteria such as Escherichia coli will often consume one sugar at a time when fed multiple sugars, in a process known as carbon catabolite repression. The classic example involves glucose and lactose, where E. coli will first consume glucose, and only when it has consumed all of the glucose will it begin to consume lactose. In addition to that of lactose, glucose also represses the consumption of many other sugars, including arabinose and xylose. In this work, we characterized a second hierarchy in E. coli, that between arabinose and xylose. We show that, when grown in a mixture of the two pentoses, E. coli will consume arabinose before it consumes xylose. Consistent with a mechanism involving catabolite repression, the expression of the xylose metabolic genes is repressed in the presence of arabinose. We found that this repression is AraC dependent and involves a mechanism where arabinose-bound AraC binds to the xylose promoters and represses gene expression. Collectively, these results demonstrate that sugar utilization in E. coli involves multiple layers of regulation, where cells will consume first glucose, then arabinose, and finally xylose. These results may be pertinent in the metabolic engineering of E. coli strains capable of producing chemical and biofuels from mixtures of hexose and pentose sugars derived from plant biomass.

  15. Escherichia coli sequence type 131: epidemiology and challenges in treatment.

    PubMed

    Qureshi, Zubair A; Doi, Yohei

    2014-05-01

    Escherichia coli ST131 has emerged as a global epidemic, multidrug-resistant clone of E. coli causing extra-intestinal infections. It is now highly prevalent among fluoroquinolone-resistant and CTX-M ESBL-producing E. coli isolates worldwide. Humans are likely the primary reservoir of ST131. Factors associated with its acquisition include residence in long-term care facilities and recent receipt of antimicrobial agents. E. coli ST131 causes a wide array of infections ranging from cystitis to life-threatening sepsis. Fluoroquinolones and trimethoprim-sulfamethoxazole are no longer adequate options for empiric therapy when E. coli ST131 is suspected from risk factors and local epidemiology. Expanded-spectrum cephalosporins, piperacillin-tazobactam and carbapenems are options to treat serious non-ESBL-producing E. coli ST131 infections, while carbapenems are indicated for ESBL-producing infections. There is a growing interest in reevaluating oral agents including fosfomycin and pivmecillinam for less serious infections such as uncomplicated cystitis.

  16. Characterization of Shiga toxigenic Escherichia coli isolated from foods.

    PubMed

    Martínez, Aida Juliana; Bossio, Carolina Paba; Durango, Adriana Coral; Vanegas, Maria Consuelo

    2007-12-01

    The aim of this study was to characterize Shiga toxigenic Escherichia coli (STEC) by PCR using strains isolated from ham, beef, and cattle in Colombia. A total of 189 E. coli strains were tested for the presence of the uidA, stx1, and stx2 genes, and identification was confirmed by the automated PCR BAX system for E. coli O157:H7. Genes encoding Shiga-like toxins (stx) were found in eight (6.06%) of 132 strains previously isolated from minced beef; four (50%) of these strains yielded amplification products for both toxin genes (stx1 and stx2), and four (50%) yielded products only for the stx2 toxin. None of the strains analyzed were positive by PCR for the presence of the single base-pair mutation in the uidA gene from E. coli O157:H7; these results were confirmed by the BAX system analysis. A multiplex PCR assay was standardized for the three genes. Results from this study confirmed previous data about the low prevalence of E. coli O157:H7 and Shiga-like toxins in Colombia and is the first known report of the prevalence of non-O157 enterohemorrhagic E. coli in this country.

  17. [Avian Escherichia coli virulence factors associated with coli septicemia in broiler chickens].

    PubMed

    Ramirez Santoyo, R M; Moreno Sala, A; Almanza Marquez, Y

    2001-01-01

    In order to detect phenotypic characteristics associated with pathogenicity, 25 strains of Escherichia coli, isolated from clinical cases of colisepticemia in broiler chickens, were examined to determine the following properties: colicinogenicity, colicin V production, type 1 fimbriae, hemolysin expression and motility. Colicinogenicity occurred in 72% of the strains, 56% of all strains produced colicin V, 84% were positive for type 1 fimbriae and 80% were positive for motility. None of the strains had hemolytic activity; however, all of them, expressed at least one of the other characteristics studied. These results suggest that the diversity of phenotypes detected partially explain the multifactorial nature of avian colisepticemia.

  18. Regulation of Glutamine Transport in Escherichia coli.

    PubMed Central

    Willis, R C; Iwata, K K; Furlong, C E

    1975-01-01

    The formation of the high-affinity (Km equal to 0.2 muM) L-glutamine transport system of Escherichia coli strain 7 (Lin) appears to be subject to the same major control as the glutamine synthetase (EC 6.3.1.2) of this gram-negative organism. Culture of cells under nitrogen-limited conditions provides maximum derepression of both the glutamine synthetase and the glutamine transport system. Nutritional conditions providing a rich supply of ammonium salts or available sources of nitrogen, i.e., conditions which repress the formation of glutamine synthetase, provide three- and 20-fold repression, respectively, of the glutamine transport system. Culture of cells with glutamine supplements of 2 mM does not increase the repression of high-affinity glutamine transport system beyond the level observed in the absence of glutamine. A second kinetically distinct low-affinity component of glutamine. A second kinetically distinct low-affinity component of glutamine uptake is observed in cells cultured with a glutamine-depleted nutrient broth. This second component is associated with the appearance of glutaminase A (EC 3.5.1.2) and asparaginase I (EC 3.5.1.1), a periplasmic enzyme. Parallel changes were observed in the levels of the high-affinity glutamine transport system and the glutamine synthetase when cells were cultured with the carbon sources: glucose, glycerol, or succinate. PMID:238938

  19. ESCHERICHIA COLI Gene Induction by Alkylation Treatment

    PubMed Central

    Volkert, Michael R.; Nguyen, Dinh C.; Beard, K. Christopher

    1986-01-01

    Searches for alkylation-inducible (aid) genes of Escherichia coli have been conducted by screening random fusions of the Mu-dl(ApR lac) phage for fusions showing increased β-galactosidase activity after treatment with methylating agents, but not after treatments with UV-irradiation. In this report we describe gene fusions that are specifically induced by alkylation treatments. Nine new mutants are described, and their properties are compared with the five mutants described previously. The total of 14 fusion mutants map at five distinct genetic loci. They can be further subdivided on the basis of their induction by methyl methanesulfonate (MMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). alkA, aidB and aidD are induced by both agents and appear to be regulated by ada. Neither aidC nor aidI is regulated by ada. Moreover, since aidC is induced only by MNNG and aidI is induced only by MMS, these two genes are likely to be individually regulated. Thus, there appear to be at least three different regulatory mechanisms controlling aid genes. PMID:3080354

  20. Escherichia coli gene induction by alkylation treatment.

    PubMed

    Volkert, M R; Nguyen, D C; Beard, K C

    1986-01-01

    Searches for alkylation-inducible (aid) genes of Escherichia coli have been conducted by screening random fusions of the Mu-dl(ApR lac) phage for fusions showing increased beta-galactosidase activity after treatment with methylating agents, but not after treatments with UV-irradiation. In this report we describe gene fusions that are specifically induced by alkylation treatments. Nine new mutants are described, and their properties are compared with the five mutants described previously. The total of 14 fusion mutants map at five distinct genetic loci. They can be further subdivided on the basis of their induction by methyl methanesulfonate (MMS) and N-methyl-N' -nitro-N-nitrosoguanidine (MNNG). alkA, aidB and aidD are induced by both agents and appear to be regulated by ada. Neither aidC nor aidI is regulated by ada. Moreover, since aidC is induced only by MNNG and aidI is induced only by MMS, these two genes are likely to be individually regulated. Thus, there appear to be at least three different regulatory mechanisms controlling aid genes.

  1. Regulation of alcohol fermentation by Escherichia coli

    SciTech Connect

    Clark, D.P.

    1986-03-01

    The purpose of this project is to elucidate the way in which the fermentative synthesis of ethanol is regulated in the facultative anaerobe Escherichia coli. Focus is on the two final steps in alcohol synthesis, which are catalyzed by alcohol dehydrogenase and acetaldehyde CoA dehydrogenase. We have isolated a series of mutations affecting the expression of these enzymes. Some of these mutations are in the structural genes for these enzymes; others affect the regulation of the adh operon. We have recently cloned the genes coding for these enzymes and are now studying the effect of multiple copies of the adh gene on fermentative growth and its regulation. A recently invented technique, proton suicide has allowed the selection of a variety of novel mutants affecting fermentation which are presently being characterized. We have isolated a comprehensive collection of operon fusions in which the lacZ structural gene is fused to promoters that are inactive aerobically but active anaerobically. Although these genes (like adh) are only expressed under anaerobic conditions, the level of induction varies from two-fold to nearly 100-fold. The nitrogen source, medium pH, nature of the buffer, presence of alternative electron acceptors (e.g., nitrate), and other factors exert a great effect on the expression of many of these genes. In the near future we will investigate control mechanisms common to the adh operon and other anaerobically regulated genes.

  2. Antimicrobial-resistant Invasive Escherichia coli, Spain

    PubMed Central

    Oteo, Jesús; Lázaro, Edurne; de Abajo, Francisco J.; Baquero, Fernando; Campos, José

    2005-01-01

    To address the public health problem of antimicrobial resistance, the European Union founded the European Antimicrobial Resistance Surveillance System. A network of 32 Spanish hospitals, serving ≈9.6 million persons, submitted antimicrobial-susceptibility data on 7,098 invasive Escherichia coli species (2001–2003). Resistance to ampicillin, cotrimoxazole, ciprofloxacin, gentamicin, and tobramycin was found at rates of 59.9%, 32.6%, 19.3%, 6.8%, and 5.3%, respectively. Resistance to multiple drugs increased from 13.8% in 2001 to 20.6% in 2003 (p <0.0001). Antimicrobial consumption data were obtained from the Spanish National Health System. In spite of decreased cephalosporin and β-lactam use, overall extended-spectrum β-lactamase production increased from 1.6% (2001) to 4.1% (2003) (p <0.0001), mainly due to the rising prevalence of cefotaximases. Resistance to ciprofloxacin significantly increased, mostly in community-onset infections, which coincided with a rise in community quinolone use. Cotrimoxazole resistance remained stable at ≈30%, even though its use was dramatically reduced. PMID:15829192

  3. Starvation-induced dormancy in E. coli

    NASA Astrophysics Data System (ADS)

    Simsek, Emrah; Kim, Minsu

    Isogenic bacterial populations can exhibit phenotypic heterogeneity. Phenotypic heterogeneity is often viewed as a bet-hedging strategy to cope with environmental fluctuations, and believed to be under genetic control. The experimental evidence of this view, however, is limited. Here, we report experimental evidence that prompts reconsideration of this view. Observing how starved E. coli cells resume growth upon nutrient upshift at the single-cell level in real time, we revealed that physiological and metabolic state of starved cells, as well as growth resumption kinetics, vary from cell to cell. Upon nutrient upshift, a majority of cells resume growth instantly, but a small fraction maintain a non-growth state for several hours or days (i.e., long lag time). Hence they are dormant cells. The fraction strongly depends on the duration of starvation. The dormancy does not confer resistance to starvation. Oxidative damage accumulated during starvation leads to the appearance of dormant cells. Taken together, our data suggests that a dormant subpopulation appears as an inevitable consequence of starvation, rather than cellular decision to cope with starvation. Hence, the existence of a genetic program and adaptive value as a bet-hedging strategy to cope with starvation stress may not be needed to explain the emergence of bacterial dormancy.

  4. Optimal search in E. coli chemotaxis

    NASA Astrophysics Data System (ADS)

    Dev, Subrata; Chatterjee, Sakuntala

    2015-04-01

    We study chemotaxis of a single E. coli bacterium in a medium where the nutrient chemical is also undergoing diffusion and its concentration has the form of a Gaussian whose width increases with time. We measure the average first passage time of the bacterium at a region of high nutrient concentration. In the limit of very slow nutrient diffusion, the bacterium effectively experiences a Gaussian concentration profile with a fixed width. In this case we find that there exists an optimum width of the Gaussian when the average first passage time is minimum, i.e., the search process is most efficient. We verify the existence of the optimum width for the deterministic initial position of the bacterium and also for the stochastic initial position, drawn from uniform and steady state distributions. Our numerical simulation in a model of a non-Markovian random walker agrees well with our analytical calculations in a related coarse-grained model. We also present our simulation results for the case when the nutrient diffusion and bacterial motion occur over comparable time scales and the bacterium senses a time-varying concentration field.

  5. Genotoxicity of Graphene in Escherichia coli

    NASA Astrophysics Data System (ADS)

    Sharma, Ananya

    Rapid advances in nanotechnology necessitate assessment of the safety of nanomaterials in the resulting products and applications. One key nanomaterial attracting much interest in many areas of science and technology is graphene. Graphene is a one atom thick carbon allotrope arranged in a two-dimensional honeycomb lattice. In addition to being extremely thin, graphene has several extraordinary physical properties such as its exceptional mechanical strength, thermal stability, and high electrical conductivity. Graphene itself is relatively chemically inert and therefore pristine graphene must undergo a process called functionalization, which is combination of chemical and physical treatments that change the properties of graphene, to make it chemically active. Functionalization of graphene is of crucial importance as the end application of graphene depends on proper functionalization. In the field of medicine, graphene is currently a nanomaterial of high interest for building biosensors, DNA transistors, and probes for cancer detection. Despite the promising applications of graphene in several areas of biomedicine, there have been only few studies in recent years that focus on evaluating cytotoxicity of graphene on cells, and almost no studies that investigate how graphene exposure affects cellular genetic material. Therefore, in this study we used a novel approach to evaluate the genotoxicity, i.e., the effects of graphene on DNA, using Escherichia coli as a prokaryotic model organism.

  6. Oligosaccharide Binding in Escherichia coli Glycogen Synthase

    SciTech Connect

    Sheng, Fang; Yep, Alejandra; Feng, Lei; Preiss, Jack; Geiger, James H.

    2010-11-17

    Glycogen/starch synthase elongates glucan chains and is the key enzyme in the synthesis of glycogen in bacteria and starch in plants. Cocrystallization of Escherichia coli wild-type glycogen synthase (GS) with substrate ADPGlc and the glucan acceptor mimic HEPPSO produced a closed form of GS and suggests that domain-domain closure accompanies glycogen synthesis. Cocrystallization of the inactive GS mutant E377A with substrate ADPGlc and oligosaccharide results in the first oligosaccharide-bound glycogen synthase structure. Four bound oligosaccharides are observed, one in the interdomain cleft (G6a) and three on the N-terminal domain surface (G6b, G6c, and G6d). Extending from the center of the enzyme to the interdomain cleft opening, G6a mostly interacts with the highly conserved N-terminal domain residues lining the cleft of GS. The surface-bound oligosaccharides G6c and G6d have less interaction with enzyme and exhibit a more curled, helixlike structural arrangement. The observation that oligosaccharides bind only to the N-terminal domain of GS suggests that glycogen in vivo probably binds to only one side of the enzyme to ensure unencumbered interdomain movement, which is required for efficient, continuous glucan-chain synthesis.

  7. Biochemistry of homologous recombination in Escherichia coli.

    PubMed Central

    Kowalczykowski, S C; Dixon, D A; Eggleston, A K; Lauder, S D; Rehrauer, W M

    1994-01-01

    Homologous recombination is a fundamental biological process. Biochemical understanding of this process is most advanced for Escherichia coli. At least 25 gene products are involved in promoting genetic exchange. At present, this includes the RecA, RecBCD (exonuclease V), RecE (exonuclease VIII), RecF, RecG, RecJ, RecN, RecOR, RecQ, RecT, RuvAB, RuvC, SbcCD, and SSB proteins, as well as DNA polymerase I, DNA gyrase, DNA topoisomerase I, DNA ligase, and DNA helicases. The activities displayed by these enzymes include homologous DNA pairing and strand exchange, helicase, branch migration, Holliday junction binding and cleavage, nuclease, ATPase, topoisomerase, DNA binding, ATP binding, polymerase, and ligase, and, collectively, they define biochemical events that are essential for efficient recombination. In addition to these needed proteins, a cis-acting recombination hot spot known as Chi (chi: 5'-GCTGGTGG-3') plays a crucial regulatory function. The biochemical steps that comprise homologous recombination can be formally divided into four parts: (i) processing of DNA molecules into suitable recombination substrates, (ii) homologous pairing of the DNA partners and the exchange of DNA strands, (iii) extension of the nascent DNA heteroduplex; and (iv) resolution of the resulting crossover structure. This review focuses on the biochemical mechanisms underlying these steps, with particular emphases on the activities of the proteins involved and on the integration of these activities into likely biochemical pathways for recombination. Images PMID:7968921

  8. Endonuclease IV (nfo) mutant of Escherichia coli.

    PubMed Central

    Cunningham, R P; Saporito, S M; Spitzer, S G; Weiss, B

    1986-01-01

    A cloned gene, designated nfo, caused overproduction of an EDTA-resistant endonuclease specific for apurinic-apyrimidinic sites in DNA. The sedimentation coefficient of the enzyme was similar to that of endonuclease IV. An insertion mutation was constructed in vitro and transferred from a plasmid to the Escherichia coli chromosome. nfo mutants had an increased sensitivity to the alkylating agents methyl methanesulfonate and mitomycin C and to the oxidants tert-butyl hydroperoxide and bleomycin. The nfo mutation enhanced the killing of xth (exonuclease III) mutants by methyl methanesulfonate, H2O2, tert-butyl hydroperoxide, and gamma rays, and it enhanced their mutability by methyl methanesulfonate. It also increased the temperature sensitivity of an xth dut (dUTPase) mutant that is defective in the repair of uracil-containing DNA. These results are consistent with earlier findings that endonuclease IV and exonuclease III both cleave DNA 5' to an apurinic-apyrimidinic site and that exonuclease III is more active. However, nfo mutants were more sensitive to tert-butyl hydroperoxide and to bleomycin than were xth mutants, suggesting that endonuclease IV might recognize some lesions that exonuclease III does not. The mutants displayed no marked increase in sensitivity to 254-nm UV radiation, and the addition of an nth (endonuclease III) mutation to nfo or nfo xth mutants did not significantly increase their sensitivity to any of the agents tested. Images PMID:2430946

  9. Ribonuclease Sensitivity of Escherichia coli Ribosomes

    PubMed Central

    Santer, Melvin; Smith, Josephine R.

    1966-01-01

    Santer, Melvin (Haverford College, Haverford, Pa.), and Josephine R. Smith. Ribonuclease sensitivity of Escherichia coli ribosomes. J. Bacteriol. 92:1099–1110. 1966.—The ribonucleic acid (RNA) contained in 70S ribosomes and in 50S and 30S subunits was hydrolyzed by pancreatic ribonuclease. A 7% amount of the RNA was removed from the 70S particle; at 10−4m magnesium concentration, a maximum of 24 and 30% of the RNA in the 50S and the 30S fractions, respectively, was removed by ribonuclease. At the two lower magnesium ion concentrations, 50S ribosomes did not lose any protein, whereas 30S ribosomes lost protein as a result of ribonuclease treatment. A number of proteins were removed from the 30S particles by ribonuclease, and these proteins were antigenically related to proteins present in 50S ribosomes. The differential effect of ribonuclease on 50S and 30S ribosomes suggested that they have structural dissimilarities. Images PMID:5332866

  10. Prevalence of Escherichia coli sequence type 131 and its H30 subclone among E. coli isolates in a French hospital.

    PubMed

    Lafolie, Jeremy; Nicolas-Chanoine, Marie-Hélène; Grenouillet, Frédéric; Hocquet, Didier; Bertrand, Xavier

    2014-11-01

    The prevalence of Escherichia coli sequence type 131 (ST131) and its subclone H30 was assessed among a collection of 490 E. coli isolated in 2013 in a French university hospital. The prevalence of ST131 was 4% among bloodstream isolates (regardless of antimicrobial resistance) and 17.2% among extended-spectrum β-lactamase (ESBL)-producing isolates. Although a much lower prevalence of ST131 was found among bloodstream E. coli isolates compared with other countries, a large predominance of H30 subclone within ST131 was confirmed. It was also confirmed that, among ESBL-producing E. coli, ST131 isolates were more frequently resistant to amoxicillin/clavulanic acid, ceftazidime, fluoroquinolones and aminoglycosides than non-ST131 isolates.

  11. Phenotypic microarrays suggest Escherichia coli ST131 is not a metabolically distinct lineage of extra-intestinal pathogenic E. coli.

    PubMed

    Alqasim, Abdulaziz; Emes, Richard; Clark, Gemma; Newcombe, Jane; La Ragione, Roberto; McNally, Alan

    2014-01-01

    Extraintestinal pathogenic E. coli (ExPEC) are the major aetiological agent of urinary tract infections (UTIs) in humans. The emergence of the CTX-M producing clone E. coli ST131 represents a major challenge to public health worldwide. A recent study on the metabolic potential of E. coli isolates demonstrated an association between the E. coli ST131 clone and enhanced utilisation of a panel of metabolic substrates. The studies presented here investigated the metabolic potential of ST131 and other major ExPEC ST isolates using 120 API test reagents and found that ST131 isolates demonstrated a lower metabolic activity for 5 of 120 biochemical tests in comparison to non-ST131 ExPEC isolates. Furthermore, comparative phenotypic microarray analysis showed a lack of specific metabolic profile for ST131 isolates countering the suggestion that these bacteria are metabolically fitter and therefore more successful human pathogens.

  12. Escherichia coli EDL933 requires gluconeogenic nutrients to successfully colonize the intestines of streptomycin-treated mice precolonized with E. coli Nissle 1917.

    PubMed

    Schinner, Silvia A C; Mokszycki, Matthew E; Adediran, Jimmy; Leatham-Jensen, Mary; Conway, Tyrrell; Cohen, Paul S

    2015-05-01

    Escherichia coli MG1655, a K-12 strain, uses glycolytic nutrients exclusively to colonize the intestines of streptomycin-treated mice when it is the only E. coli strain present or when it is confronted with E. coli EDL933, an O157:H7 strain. In contrast, E. coli EDL933 uses glycolytic nutrients exclusively when it is the only E. coli strain in the intestine but switches in part to gluconeogenic nutrients when it colonizes mice precolonized with E. coli MG1655 (R. L. Miranda et al., Infect Immun 72:1666-1676, 2004, http://dx.doi.org/10.1128/IAI.72.3.1666-1676.2004). Recently, J. W. Njoroge et al. (mBio 3:e00280-12, 2012, http://dx.doi.org/10.1128/mBio.00280-12) reported that E. coli 86-24, an O157:H7 strain, activates the expression of virulence genes under gluconeogenic conditions, suggesting that colonization of the intestine with a probiotic E. coli strain that outcompetes O157:H7 strains for gluconeogenic nutrients could render them nonpathogenic. Here we report that E. coli Nissle 1917, a probiotic strain, uses both glycolytic and gluconeogenic nutrients to colonize the mouse intestine between 1 and 5 days postfeeding, appears to stop using gluconeogenic nutrients thereafter in a large, long-term colonization niche, but continues to use them in a smaller niche to compete with invading E. coli EDL933. Evidence is also presented suggesting that invading E. coli EDL933 uses both glycolytic and gluconeogenic nutrients and needs the ability to perform gluconeogenesis in order to colonize mice precolonized with E. coli Nissle 1917. The data presented here therefore rule out the possibility that E. coli Nissle 1917 can starve the O157:H7 E. coli strain EDL933 of gluconeogenic nutrients, even though E. coli Nissle 1917 uses such nutrients to compete with E. coli EDL933 in the mouse intestine.

  13. Fungal β-1,3-glucan increases ofloxacin tolerance of Escherichia coli in a polymicrobial E. coli/Candida albicans biofilm.

    PubMed

    De Brucker, Katrijn; Tan, Yulong; Vints, Katlijn; De Cremer, Kaat; Braem, Annabel; Verstraeten, Natalie; Michiels, Jan; Vleugels, Jef; Cammue, Bruno P A; Thevissen, Karin

    2015-01-01

    In the past, biofilm-related research has focused mainly on axenic biofilms. However, in nature, biofilms are often composed of multiple species, and the resulting polymicrobial interactions influence industrially and clinically relevant outcomes such as performance and drug resistance. In this study, we show that Escherichia coli does not affect Candida albicans tolerance to amphotericin or caspofungin in an E. coli/C. albicans biofilm. In contrast, ofloxacin tolerance of E. coli is significantly increased in a polymicrobial E. coli/C. albicans biofilm compared to its tolerance in an axenic E. coli biofilm. The increased ofloxacin tolerance of E. coli is mainly biofilm specific, as ofloxacin tolerance of E. coli is less pronounced in polymicrobial E. coli/C. albicans planktonic cultures. Moreover, we found that ofloxacin tolerance of E. coli decreased significantly when E. coli/C. albicans biofilms were treated with matrix-degrading enzymes such as the β-1,3-glucan-degrading enzyme lyticase. In line with a role for β-1,3-glucan in mediating ofloxacin tolerance of E. coli in a biofilm, we found that ofloxacin tolerance of E. coli increased even more in E. coli/C. albicans biofilms consisting of a high-β-1,3-glucan-producing C. albicans mutant. In addition, exogenous addition of laminarin, a polysaccharide composed mainly of poly-β-1,3-glucan, to an E. coli biofilm also resulted in increased ofloxacin tolerance. All these data indicate that β-1,3-glucan from C. albicans increases ofloxacin tolerance of E. coli in an E. coli/C. albicans biofilm.

  14. Prevalence of avian-pathogenic Escherichia coli strain O1 genomic islands among extraintestinal and commensal E. coli isolates.

    PubMed

    Johnson, Timothy J; Wannemuehler, Yvonne; Kariyawasam, Subhashinie; Johnson, James R; Logue, Catherine M; Nolan, Lisa K

    2012-06-01

    Escherichia coli strains that cause disease outside the intestine are known as extraintestinal pathogenic E. coli (ExPEC) and include pathogens of humans and animals. Previously, the genome of avian-pathogenic E. coli (APEC) O1:K1:H7 strain O1, from ST95, was sequenced and compared to those of several other E. coli strains, identifying 43 genomic islands. Here, the genomic islands of APEC O1 were compared to those of other sequenced E. coli strains, and the distribution of 81 genes belonging to 12 APEC O1 genomic islands among 828 human and avian ExPEC and commensal E. coli isolates was determined. Multiple islands were highly prevalent among isolates belonging to the O1 and O18 serogroups within phylogenetic group B2, which are implicated in human neonatal meningitis. Because of the extensive genomic similarities between APEC O1 and other human ExPEC strains belonging to the ST95 phylogenetic lineage, its ability to cause disease in a rat model of sepsis and meningitis was assessed. Unlike other ST95 lineage strains, APEC O1 was unable to cause bacteremia or meningitis in the neonatal rat model and was significantly less virulent than uropathogenic E. coli (UPEC) CFT073 in a mouse sepsis model, despite carrying multiple neonatal meningitis E. coli (NMEC) virulence factors and belonging to the ST95 phylogenetic lineage. These results suggest that host adaptation or genome modifications have occurred either in APEC O1 or in highly virulent ExPEC isolates, resulting in differences in pathogenicity. Overall, the genomic islands examined provide targets for further discrimination of the different ExPEC subpathotypes, serogroups, phylogenetic types, and sequence types.

  15. Effect of tannins on the in viro growth of Escherichia coli O157:H7 and in vivo growth of generic Escherichia coli excreted from steers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement o...

  16. Modeling the inactivation of Escherichia coli 0157:H7 and uropathogenic E.coli in ground chicken by high pressure processing and thymol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compare the resistance of iPEC (O157:H7) to UPEC in chicken meat using High Pressure Processing...

  17. Genetic and Physical Structure of Salmonella-coli Phage Hybrids and Development of New Generalized Transducing Hybrid Phages for E. Coli.

    DTIC Science & Technology

    1984-05-01

    coli chromosome although the parental phage Mu80, is a specialized transducing phage for the E . coli trp operon. Phage P22 can recombine with coli...mutator phage Mu. Genetic analysis of Mu80immP22 hybrid genomes led us to isolate high specialized transducing phages for argF and proAB genes of the E

  18. Modeling the inactivatin of Escherichia coli 0157:H7 and uropathogenic E. coli in ground beef by high pressure processing and citral

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compared the resistance of iPEC (O157:H7) to UPEC in ground beef using High Pressure Processing...

  19. 77 FR 58091 - Risk-Based Sampling of Beef Manufacturing Trimmings for Escherichia coli (E. coli) O157:H7 and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-19

    ... Food Safety and Inspection Service Risk-Based Sampling of Beef Manufacturing Trimmings for Escherichia coli (E. coli) O157:H7 and Plans for Beef Baseline AGENCY: Food Safety and Inspection Service (FSIS), U... announcing its intention to redesign its E. coli O157:H7 verification testing program for beef...

  20. Binding and Cleavage of E. coli HUβ by the E. coli Lon Protease

    PubMed Central

    Liao, Jiahn-Haur; Lin, Yu-Ching; Hsu, Jowey; Lee, Alan Yueh-Luen; Chen, Tse-An; Hsu, Chun-Hua; Chir, Jiun-Ly; Hua, Kuo-Feng; Wu, Tzu-Hua; Hong, Li-Jenn; Yen, Pei-Wen; Chiou, Arthur; Wu, Shih-Hsiung

    2010-01-01

    Abstract The Escherichia coli Lon protease degrades the E. coli DNA-binding protein HUβ, but not the related protein HUα. Here we show that the Lon protease binds to both HUβ and HUα, but selectively degrades only HUβ in the presence of ATP. Mass spectrometry of HUβ peptide fragments revealed that region K18-G22 is the preferred cleavage site, followed in preference by L36-K37. The preferred cleavage site was further refined to A20-A21 by constructing and testing mutant proteins; Lon degraded HUβ-A20Q and HUβ-A20D more slowly than HUβ. We used optical tweezers to measure the rupture force between HU proteins and Lon; HUα, HUβ, and HUβ-A20D can bind to Lon, and in the presence of ATP, the rupture force between each of these proteins and Lon became weaker. Our results support a mechanism of Lon protease cleavage of HU proteins in at least three stages: binding of Lon with the HU protein (HUβ, HUα, or HUβ-A20D); hydrolysis of ATP by Lon to provide energy to loosen the binding to the HU protein and to allow an induced-fit conformational change; and specific cleavage of only HUβ. PMID:20085725

  1. The Melibiose Transporter of Escherichia coli

    PubMed Central

    Fuerst, Oliver; Lin, Yibin; Granell, Meritxell; Leblanc, Gérard; Padrós, Esteve; Lórenz-Fonfría, Víctor A.; Cladera, Josep

    2015-01-01

    We examine the role of Lys-377, the only charged residue in helix XI, on the functional mechanism of the Na+-sugar melibiose symporter from Escherichia coli. Intrinsic fluorescence, FRET, and Fourier transform infrared difference spectroscopy reveal that replacement of Lys-377 with either Cys, Val, Arg, or Asp disables both Na+ and melibiose binding. On the other hand, molecular dynamics simulations extending up to 200–330 ns reveal that Lys-377 (helix XI) interacts with the anionic side chains of two of the three putative ligands for cation binding (Asp-55 and Asp-59 in helix II). When Asp-59 is protonated during the simulations, Lys-377 preferentially interacts with Asp-55. Interestingly, when a Na+ ion is positioned in the Asp-55-Asp-59 environment, Asp-124 in helix IV (a residue essential for melibiose binding) reorients and approximates the Asp-55-Asp-59 pair, and all three acidic side chains act as Na+ ligands. Under these conditions, the side chain of Lys-377 interacts with the carboxylic moiety of these three Asp residues. These data highlight the crucial role of the Lys-377 residue in the spatial organization of the Na+ binding site. Finally, the analysis of the second-site revertants of K377C reveals that mutation of Ile-22 (in helix I) preserves Na+ binding, whereas that of melibiose is largely abolished according to spectroscopic measurements. This amino acid is located in the border of the sugar-binding site and might participate in sugar binding through apolar interactions. PMID:25971963

  2. Novel Mechanism of Escherichia coli Porin Regulation

    PubMed Central

    Castillo-Keller, Maria; Vuong, Phu; Misra, Rajeev

    2006-01-01

    A novel mechanism of Escherichia coli porin regulation was discovered from multicopy suppressors that permitted growth of cells expressing a mutant OmpC protein in the absence of DegP. Analyses of two suppressors showed that both substantially lowered OmpC expression. Suppression activities were confined to a short DNA sequence, which we designated ipeX for inhibition of porin expression, and to DNA containing a 3′-truncated ompR gene. The major effect of ipeX on ompC expression was exerted posttranscriptionally, whereas the truncated OmpR protein reduced ompC transcription. ipeX was localized within an untranslated region of 247 base pairs between the stop codon of nmpC—a remnant porin gene from the cryptic phage qsr′ (DLP12) genome—and its predicted Rho-independent transcriptional terminator. Interestingly, another prophage, PA-2, which encodes a porin similar to NmpC, known as Lc, has sequences downstream from lc identical to that of ipeX. PA-2 lysogenization leads to Lc expression and OmpC inhibition. Our data show that the synthesis of the lc transcript, whose 3′ end contains the corresponding ipeX sequence, inhibits OmpC expression. Overexpression of ipeX RNA inhibited both OmpC and OmpF expression but not that of OmpA. ompC-phoA chimeric gene constructs revealed a 248-bp untranslated region of ompC required for ipeX-mediated inhibition. However, no sequence complementarity was found between ipeX and this region of ompC, indicating that inhibition may not involve simple base pairing between the two RNA molecules. The effect of ipeX on ompC, but not on ompF, was independent of the RNA chaperone Hfq. PMID:16385048

  3. Current World Status of Balantidium coli

    PubMed Central

    Schuster, Frederick L.; Ramirez-Avila, Lynn

    2008-01-01

    Balantidium coli is a cosmopolitan parasitic-opportunistic pathogen that can be found throughout the world. Pigs are its reservoir hosts, and humans become infected through direct or indirect contact with pigs. In rural areas and in some developing countries where pig and human fecal matter contaminates the water supply, there is a greater likelihood that balantidiosis may develop in humans. The infection may be subclinical in humans, as it mostly is in pigs, or may develop as a fulminant infection with bloody and mucus-containing diarrhea; this can lead to perforation of the colon. The disease responds to treatment with tetracycline or metronidazole. Balantidiosis is a disease that need never exist given access to clean water and a public health infrastructure that monitors the water supply and tracks infections. Its spread can be limited by sanitary measures and personal hygiene, but it is a disease that will be around as long as there are pigs. Immunocompromised individuals have developed balantidiosis without any direct contact with pigs, perhaps with rats or contaminated produce as a possible source of infection. For the clinician, balanatidiosis should be included in the differential diagnosis for persistent diarrhea in travelers to or from Southeast Asia, the Western Pacific islands, rural South America, or communities where close contact with domestic swine occurs. Warming of the earth's surface may provide a more favorable environment, even in the now-temperate areas of the world, for survival of trophic and cystic stages of Balantidium, and its prevalence may increase. Effective sanitation and uncontaminated water are the most useful weapons against infection. Fortunately, balantidiosis responds to antimicrobial therapy, and there have been no reports of resistance to the drugs of choice. PMID:18854484

  4. Effect of Ampicillin on E. Coli of Swine Origin

    PubMed Central

    Chopra, S. L.; Dale, D. G.; Blackwood, A. G.

    1963-01-01

    The in vitro susceptibility of 103 cultures of E. coli isolated from scouring and nonscouring pigs, and four cultures of Salmonella isolated from a case of necrotic enteritis was tested against Ampicillin contained in nutrient broth at concentrations of 0, 0.1, 1.0 and 5.0 uG per ml. of the medium. All but three cultures of E. coli were found to be susceptible to 5.0 uG/ml., all Salmonella isolates were also susceptible to this concentration of the antibiotic. Susceptibility of E. coli was also tested by plating dilutions of fecal samples obtained from either a scouring or a nonscouring pig, with E.M.B. agar containing 0, 0.1, 1.0, 2.5, 5.0 and 10.0 uG Ampicillin per ml. of the medium. No difference in the growth of E. coli was observed at 0, 0.1 and 1.0 uG concentrations. The three higher concentrations of the antibiotic inhibited the growth of E. coli proportional to the amount of Ampicillin in each concentration. Ampicillin proved very effective in alleviating the symptoms of hemorrhagic enteritis in a 11-week old pig. The disappearance of scours was associated with the replacement of the previously existing sero-biotypes of fecal E. coliwith another aberrant type of E.coli which produced H2S. No Ampicillin resistant strains of E. coli emerged following treatment of the animal with this antibiotic. ImagesFig. IIp227-a PMID:17649462

  5. Genotyping and virulence factors assessment of bovine mastitis Escherichia coli.

    PubMed

    Blum, Shlomo E; Leitner, Gabriel

    2013-05-03

    Escherichia coli is a major agent of bovine mastitis worldwide. However, specific E. coli virulence factors associated to pathogenicity during intra-mammary infections are yet unknown and this pathotype remains uncharacterized. The objectives of the present work were to assess the presence of a wide range of known virulence factors in a large set of E. coli strains isolated from bovine mastitis (mastitis set) and to study the genotypic distribution of strains in the mastitis set in comparison to a set of strains isolated from cows' environment in dairy farms (environmental set). Virulence factors were assessed by DNA hybridization microarray. The three most prevalent virulence factors found in the mastitis set were lpfA (long polar fimbriae), iss (increased serum resistance) and astA (enteroaggregative E. coli heat-stable enterotoxin 1). None, however, characterized the majority of these strains. Genotyping was assessed by ECOR phylogenetic grouping, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Strains in the mastitis and environmental sets were differentially distributed into ECOR phylogenetic groups; groups A and B1 being the most prevalent ones. Multiple MLST strain types were found in the two sets of strains, but only a few were common to both, and diversity was higher in the environmental set. A variety of PFGE patterns were found in the mastitis and environmental sets. Two clusters comprising mostly highly similar mastitis strains were identified. The results confirm that mastitis E. coli strains mostly lack known E. coli virulence factors. In addition, it is shown that the genotypic diversity of mastitis strains does not reflect the diversity found in the environmental E. coli population.

  6. Distribution of core oligosaccharide types in lipopolysaccharides from Escherichia coli.

    PubMed

    Amor, K; Heinrichs, D E; Frirdich, E; Ziebell, K; Johnson, R P; Whitfield, C

    2000-03-01

    In the lipopolysaccharides of Escherichia coli there are five distinct core oligosaccharide (core OS) structures, designated K-12 and R1 to R4. The objective of this work was to determine the prevalences of these core OS types within the species. Unique sequences in the waa (core OS biosynthesis) gene operon were used to develop a PCR-based system that facilitated unequivocal determination of the core OS types in isolates of E. coli. This system was applied to the 72 isolates in the E. coli ECOR collection, a compilation of isolates that is considered to be broadly representative of the genetic diversity of the species. Fifty (69. 4%) of the ECOR isolates contained the R1 core OS, 8 (11.1%) were representatives of R2, 8 (11.1%) were R3, 2 (2.8%) were R4, and only 4 (5.6%) were K-12. R1 is the only core OS type found in all four major phylogenetic groups (A, B1, B2, and D) in the ECOR collection. Virulent extraintestinal pathogenic E. coli isolates tend to be closely related to group B2 and, to a lesser extent, group D isolates. All of the ECOR representatives from the B2 and D groups had the R1 core OS. In contrast, commensal E. coli isolates are more closely related to group A, which contains isolates representing each of the five core OS structures. R3 was the only core OS type found in 38 verotoxigenic E. coli (VTEC) isolates from humans and cattle belonging to the common enterohemorrhagic E. coli serogroups O157, O111, and O26. Although isolates from other VTEC serogroups showed more core OS diversity, the R3 type (83.1% of all VTEC isolates) was still predominant. When non-VTEC commensal isolates from cattle were analyzed, it was found that most possessed the R1 core OS type.

  7. Reduction of verotoxigenic Escherichia coli in production of fermented sausages.

    PubMed

    Holck, Askild L; Axelsson, Lars; Rode, Tone Mari; Høy, Martin; Måge, Ingrid; Alvseike, Ole; L'abée-Lund, Trine M; Omer, Mohamed K; Granum, Per Einar; Heir, Even

    2011-11-01

    After a number of foodborne outbreaks of verotoxigenic Escherichia coli involving fermented sausages, some countries have imposed regulations on sausage production. For example, the US Food Safety and Inspection Service requires a 5 log(10) reduction of E. coli in fermented products. Such regulations have led to a number of studies on the inactivation of E. coli in fermented sausages by changing processing and post-processing conditions. Several factors influence the survival of E. coli such as pre-treatment of the meat, amount of NaCl, nitrite and lactic acid, water activity, pH, choice of starter cultures and addition of antimicrobial compounds. Also process variables like fermentation temperature and storage time play important roles. Though a large variety of different production processes of sausages exist, generally the reduction of E. coli caused by production is in the range 1-2 log(10). In many cases this may not be enough to ensure microbial food safety. By optimising ingredients and process parameters it is possible to increase E. coli reduction to some extent, but in some cases still other post process treatments may be required. Such treatments may be storage at ambient temperatures, specific heat treatments, high pressure processing or irradiation. HACCP analyses have identified the quality of the raw materials, low temperature in the batter when preparing the sausages and a rapid pH drop during fermentation as critical control points in sausage production. This review summarises the literature on the reduction verotoxigenic E. coli in production of fermented sausages.

  8. Persistence of Escherichia coli in batch and continuous vermicomposting systems.

    PubMed

    Hénault-Ethier, Louise; Martin, Vincent J J; Gélinas, Yves

    2016-10-01

    Vermicomposting is a biooxidation process in which epigeicearthworms act in synergy with microbial populations to degrade organic matter. Vermicomposting does not go through a thermophilic stage as required by North American legislations for pathogen eradication. We examined the survival of a Green Fluorescent Protein (GFP) labeled Escherichia coli MG1655 as a model for the survival of pathogenic bacteria in both small-scale batch and medium-scale continuously-operated systems to discern the influence of the earthworm Eisenia fetida, nutrient content and the indigenous vermicompost microbial community on pathogen abundance. In batch systems, the microbial community had the greatest influence on the rapid decline of E. coli populations, and the effect of earthworms was only visible in microbially-impoverishedvermicomposts. No significant earthworm density-dependent relationship was observed on E. coli survival under continuous operation. E. coli numbers decreased below the US EPA compost sanitation guidelines of 10(3)Colony Forming Units (CFU)/g (dry weight) within 18-21days for both the small-scale batch and medium-scale continuous systems, but it took up to 51days without earthworms and with an impoverished microbial community to reach the legal limit. Nutrient replenishment (i.e. organic carbon) provided by continuous feed input did not appear to extend E. coli survival. In fact, longer survival of E. coli was noticed in treatments where less total and labile sugars were available, suggesting that sugars may support potentially antagonist bacteria in the vermicompost. Total N, pH and humidity did not appear to affect E. coli survival. Several opportunistic human pathogens may be found in vermicompost, and their populations are likely kept in check by antagonists.

  9. Development of a Multiplex PCR Assay for Detection of Shiga Toxin-Producing Escherichia coli, Enterohemorrhagic E. coli, and Enteropathogenic E. coli Strains

    PubMed Central

    Botkin, Douglas J.; Galli, Lucía; Sankarapani, Vinoth; Soler, Michael; Rivas, Marta; Torres, Alfredo G.

    2012-01-01

    Escherichia coli O157:H7 and other pathogenic E. coli strains are enteric pathogens associated with food safety threats and which remain a significant cause of morbidity and mortality worldwide. In the current study, we investigated whether enterohemorrhagic E. coli (EHEC), Shiga toxin-producing E. coli (STEC), and enteropathogenic E. coli (EPEC) strains can be rapidly and specifically differentiated with multiplex PCR (mPCR) utilizing selected biomarkers associated with each strain’s respective virulence genotype. Primers were designed to amplify multiple intimin (eae) and long polar fimbriae (lpfA) variants, the bundle-forming pilus gene bfpA, and the Shiga toxin-encoding genes stx1 and stx2. We demonstrated consistent amplification of genes specific to the prototype EHEC O157:H7 EDL933 (lpfA1-3, lpfA2-2, stx1, stx2, and eae-γ) and EPEC O127:H6 E2348/69 (eae-α, lpfA1-1, and bfpA) strains using the optimized mPCR protocol with purified genomic DNA (gDNA). A screen of gDNA from isolates in a diarrheagenic E. coli collection revealed that the mPCR assay was successful in predicting the correct pathotype of EPEC and EHEC clones grouped in the distinctive phylogenetic disease clusters EPEC1 and EHEC1, and was able to differentiate EHEC1 from EHEC2 clusters. The assay detection threshold was 2 × 104 CFU per PCR reaction for EHEC and EPEC. mPCR was also used to screen Argentinean clinical samples from hemolytic uremic syndrome and diarrheal patients, resulting in 91% sensitivity and 84% specificity when compared to established molecular diagnostic procedures. In conclusion, our mPCR methodology permitted differentiation of EPEC, STEC and EHEC strains from other pathogenic E. coli; therefore, the assay becomes an additional tool for rapid diagnosis of these organisms. PMID:22919600

  10. Production of 3-O-xylosyl quercetin in Escherichia coli.

    PubMed

    Pandey, Ramesh Prasad; Malla, Sailesh; Simkhada, Dinesh; Kim, Byung-Gee; Sohng, Jae Kyung

    2013-03-01

    Quercetin, a flavonol aglycone, is one of the most abundant flavonoids with high medicinal value. The bioavailability and pharmacokinetic properties of quercetin are influenced by the type of sugars attached to the molecule. To efficiently diversify the therapeutic uses of quercetin, Escherichia coli was harnessed as a production factory by the installation of various plant and bacterial UDP-xylose sugar biosynthetic genes. The genes encoding for the UDP-xylose pathway enzymes phosphoglucomutase (nfa44530), glucose-1-phosphate uridylyltransferase (galU), UDP-glucose dehydrogenase (calS8), and UDP-glucuronic acid decarboxylase (calS9) were overexpressed in E. coli BL21 (DE3) along with a glycosyltransferase (arGt-3) from Arabidopsis thaliana. Furthermore, E. coli BL21(DE3)/∆pgi, E. coli BL21(DE3)/∆zwf, E. coli BL21(DE3)/∆pgi∆zwf, and E. coli BL21(DE3)/∆pgi∆zwf∆ushA mutants carrying the aforementioned UDP-xylose sugar biosynthetic genes and glycosyltransferase and the galU-integrated E. coli BL21(DE3)/∆pgi host harboring only calS8, calS9, and arGt-3 were constructed to enhance whole-cell bioconversion of exogeneously supplied quercetin into 3-O-xylosyl quercetin. Here, we report the highest production of 3-O-xylosyl quercetin with E. coli BL21 (DE3)/∆pgi∆zwf∆ushA carrying UDP-xylose sugar biosynthetic genes and glycosyltransferase. The maximum concentration of 3-O-xylosyl quercetin achieved was 23.78 mg/L (54.75 μM), representing 54.75 % bioconversion, which was an ~4.8-fold higher bioconversion than that shown by E. coli BL21 (DE3) with the same set of genes when the reaction was carried out in 5-mL culture tubes with 100 μM quercetin under optimized conditions. Bioconversion was further improved by 98 % when the reaction was scaled up in a 3-L fermentor at 36 h.

  11. Extraintestinal Escherichia coli carrying virulence genes in coastal marine sediments.

    PubMed

    Luna, G M; Vignaroli, C; Rinaldi, C; Pusceddu, A; Nicoletti, L; Gabellini, M; Danovaro, R; Biavasco, F

    2010-09-01

    Despite the recognized potential of long-term survival or even growth of fecal indicators bacteria (FIB) in marine sediments, this compartment is largely ignored by health protection authorities. We conducted a large-scale study over approximately 50 km of the Marche coasts (Adriatic Sea) at depths ranging from 2 to 5 m. Total and fecal coliforms (FC) were counted by culture-based methods. Escherichia coli was also quantified using fluorescence in situ hybridization targeting specific 16S rRNA sequences, which yielded significantly higher abundances than culture-based methods, suggesting the potential importance of viable but nonculturable E. coli cells. Fecal coliforms displayed high abundances at most sites and showed a prevalence of E. coli. FC isolates (n = 113) were identified by API 20E, additional biochemical tests, and internal transcribed spacer-PCR. E. coli strains, representing 96% of isolates, were then characterized for genomic relatedness and phylogenetic group (A, B1, B2, and D) of origin by randomly amplified polymorphic DNA and multiplex-PCR. The results indicated that E. coli displayed a wide genotypic diversity, also among isolates from the same station, and that 44 of the 109 E. coli isolates belonged to groups B2 and D. Further characterization of B2 and D isolates for the presence of 11 virulence factor genes (pap, sfa/foc, afa, eaeA, ibeA, traT, hlyA, stx(1), stx(2), aer, and fyuA) showed that 90% of B2 and 65% of D isolates were positive for at least one of these. Most of the variance of both E. coli abundance and assemblage composition (>62%) was explained by a combination of physical-chemical and trophic variables. These findings indicate that coastal sediments could represent a potential reservoir for commensal and pathogenic E. coli and that E. coli distribution in marine coastal sediments largely depends upon the physical and trophic status of the sediment. We conclude that future sampling designs aimed at monitoring the microbiological

  12. Antibiotic Resistance in Urinary Isolates of Escherichia coli

    PubMed Central

    Abduzaimovic, Amila; Aljicevic, Mufida; Rebic, Velma; Vranic, Sabina Mahmutovic; Abduzaimovic, Kadrija; Sestic, Sabina

    2016-01-01

    Objectives: The aim of this study was to examine the presence of antimicrobial resistance / susceptibility strains of Escherichia coli in inpatients and outpatients. Materials and methods: It is a retrospective study carried out at the Department of Microbiology, Parasitology and Virology Faculty of Medicine, University of Sarajevo. In cooperation with the Microbiological laboratory of the Cantonal Hospital Zenica and the Microbiological laboratory of the General Hospital Tesanj, 3863 urine samples were processed in the period from March 1st to March 31st 2016. Results: Our study showed that E. coli had the highest antimicrobial resistance to trimethoprim / sulfamethoxazole (38.61%), followed by amoxicillin / clavulanic acid (19.62%), ciprofloxacin (9.49%), gentamicin (8.86%), cephalexin (8.23%), nitrofurantoin (8.23%), cefuroxime (7.52%), ceftazidime (6.33%), cefuroxime (89.87%), amikacin (4.43%). Conclusions: The isolated strains of E. coli showed the highest resistance to trimethoprim / sulfamethoxazole and amoxicillin / clavulanic acid. The isolated strains of E. coli showed the greatest susceptibility to amikacin and ceftazidime. Gender distribution of positive E. coli isolates showed statistically significant differences in favor of females. PMID:28144190

  13. Antibiotic Resistance of Escherichia coli Serotypes from Cochin Estuary

    PubMed Central

    Sukumaran, Divya P.; Durairaj, Srinivasan; Abdulla, Mohamed Hatha

    2012-01-01

    This study aimed at detecting the prevalence of antibiotic-resistant serotypes of Escherichia coli in Cochin estuary, India. E. coli strains were isolated during the period January 2010–December 2011 from five different stations set at Cochin estuary. Water samples from five different stations in Cochin estuary were collected on a monthly basis for a period of two years. Isolates were serotyped, antibiogram-phenotyped for twelve antimicrobial agents, and genotyped by polymerase chain reaction for uid gene that codes for β-D-glucuronidase. These E. coli strains from Cochin estuary were tested against twelve antibiotics to determine the prevalence of multiple antibiotic resistance among them. The results revealed that more than 53.33% of the isolates were multiple antibiotic resistant. Thirteen isolates showed resistance to sulphonamides and two of them contained the sul 1 gene. Class 1 integrons were detected in two E. coli strains which were resistant to more than seven antibiotics. In the present study, O serotyping, antibiotic sensitivity, and polymerase chain reaction were employed with the purpose of establishing the present distribution of multiple antibiotic-resistant serotypes, associated with E. coli isolated from different parts of Cochin estuary. PMID:23008708

  14. Escherichia coli ST131, an Intriguing Clonal Group

    PubMed Central

    Bertrand, Xavier; Madec, Jean-Yves

    2014-01-01

    SUMMARY In 2008, a previously unknown Escherichia coli clonal group, sequence type 131 (ST131), was identified on three continents. Today, ST131 is the predominant E. coli lineage among extraintestinal pathogenic E. coli (ExPEC) isolates worldwide. Retrospective studies have suggested that it may originally have risen to prominence as early as 2003. Unlike other classical group B2 ExPEC isolates, ST131 isolates are commonly reported to produce extended-spectrum β-lactamases, such as CTX-M-15, and almost all are resistant to fluoroquinolones. Moreover, ST131 E. coli isolates are considered to be truly pathogenic, due to the spectrum of infections they cause in both community and hospital settings and the large number of virulence-associated genes they contain. ST131 isolates therefore seem to contradict the widely held view that high levels of antimicrobial resistance are necessarily associated with a fitness cost leading to a decrease in pathogenesis. Six years after the first description of E. coli ST131, this review outlines the principal traits of ST131 clonal group isolates, based on the growing body of published data, and highlights what is currently known and what we need to find out to provide public health authorities with better information to help combat ST131. PMID:24982321

  15. Recent Advances in Understanding Enteric Pathogenic Escherichia coli

    PubMed Central

    Croxen, Matthew A.; Law, Robyn J.; Scholz, Roland; Keeney, Kristie M.; Wlodarska, Marta

    2013-01-01

    SUMMARY Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli. PMID:24092857

  16. The Escherichia coli Proteome: Past, Present, and Future Prospects†

    PubMed Central

    Han, Mee-Jung; Lee, Sang Yup

    2006-01-01

    Proteomics has emerged as an indispensable methodology for large-scale protein analysis in functional genomics. The Escherichia coli proteome has been extensively studied and is well defined in terms of biochemical, biological, and biotechnological data. Even before the entire E. coli proteome was fully elucidated, the largest available data set had been integrated to decipher regulatory circuits and metabolic pathways, providing valuable insights into global cellular physiology and the development of metabolic and cellular engineering strategies. With the recent advent of advanced proteomic technologies, the E. coli proteome has been used for the validation of new technologies and methodologies such as sample prefractionation, protein enrichment, two-dimensional gel electrophoresis, protein detection, mass spectrometry (MS), combinatorial assays with n-dimensional chromatographies and MS, and image analysis software. These important technologies will not only provide a great amount of additional information on the E. coli proteome but also synergistically contribute to other proteomic studies. Here, we review the past development and current status of E. coli proteome research in terms of its biological, biotechnological, and methodological significance and suggest future prospects. PMID:16760308

  17. Isolation of an Aptamer that Binds Specifically to E. coli

    PubMed Central

    Cleto, Fernanda; Krieger, Marco Aurélio; Cardoso, Josiane

    2016-01-01

    Escherichia coli is a bacterial species found ubiquitously in the intestinal flora of animals, although pathogenic variants cause major public health problems. Aptamers are short oligonucleotides that bind to targets with high affinity and specificity, and have great potential for use in diagnostics and therapy. We used cell-based Systematic Evolution of Ligands by EXponential enrichment (cell-SELEX) to isolate four single stranded DNA (ssDNA) aptamers that bind strongly to E. coli cells (ATCC generic strain 25922), with Kd values in the nanomolar range. Fluorescently labeled aptamers label the surface of E. coli cells, as viewed by fluorescent microscopy. Specificity tests with twelve different bacterial species showed that one of the aptamers–called P12-31—is highly specific for E. coli. Importantly, this aptamer binds to Meningitis/sepsis associated E. coli (MNEC) clinical isolates, and is the first aptamer described with potential for use in the diagnosis of MNEC-borne pathologies. PMID:27104834

  18. Fumarate-Mediated Persistence of Escherichia coli against Antibiotics

    PubMed Central

    Kim, Jun-Seob; Cho, Da-Hyeong; Heo, Paul; Jung, Suk-Chae; Park, Myungseo; Oh, Eun-Joong; Sung, Jaeyun; Kim, Pan-Jun; Lee, Suk-Chan; Lee, Dae-Hee; Lee, Sarah; Lee, Choong Hwan; Shin, Dongwoo

    2016-01-01

    Bacterial persisters are a small fraction of quiescent cells that survive in the presence of lethal concentrations of antibiotics. They can regrow to give rise to a new population that has the same vulnerability to the antibiotics as did the parental population. Although formation of bacterial persisters in the presence of various antibiotics has been documented, the molecular mechanisms by which these persisters tolerate the antibiotics are still controversial. We found that amplification of the fumarate reductase operon (FRD) in Escherichia coli led to a higher frequency of persister formation. The persister frequency of E. coli was increased when the cells contained elevated levels of intracellular fumarate. Genetic perturbations of the electron transport chain (ETC), a metabolite supplementation assay, and even the toxin-antitoxin-related hipA7 mutation indicated that surplus fumarate markedly elevated the E. coli persister frequency. An E. coli strain lacking succinate dehydrogenase (SDH), thereby showing a lower intracellular fumarate concentration, was killed ∼1,000-fold more effectively than the wild-type strain in the stationary phase. It appears that SDH and FRD represent a paired system that gives rise to and maintains E. coli persisters by producing and utilizing fumarate, respectively. PMID:26810657

  19. Escherichia coli β-Lactamases: What Really Matters

    PubMed Central

    Bajaj, Priyanka; Singh, Nambram S.; Virdi, Jugsharan S.

    2016-01-01

    Escherichia coli strains belonging to diverse pathotypes have increasingly been recognized as a major public health concern. The β-lactam antibiotics have been used successfully to treat infections caused by pathogenic E. coli. However, currently, the utility of β-lactams is being challenged severely by a large number of hydrolytic enzymes – the β-lactamases expressed by bacteria. The menace is further compounded by the highly flexible genome of E. coli, and propensity of resistance dissemination through horizontal gene transfer and clonal spread. Successful management of infections caused by such resistant strains requires an understanding of the diversity of β-lactamases, their unambiguous detection, and molecular mechanisms underlying their expression and spread with regard to the most relevant information about individual bacterial species. Thus, this review comprises first such effort in this direction for E. coli, a bacterial species known to be associated with production of diverse classes of β-lactamases. The review also highlights the role of commensal E. coli as a potential but under-estimated reservoir of β-lactamases-encoding genes. PMID:27065978

  20. Effects of Escherichia coli hemolysin on endothelial cell function.

    PubMed Central

    Suttorp, N; Flöer, B; Schnittler, H; Seeger, W; Bhakdi, S

    1990-01-01

    Escherichia coli hemolysin is considered an important virulence factor in extraintestinal E. coli infections. The present study demonstrates that cultured pulmonary artery endothelial cells are susceptible to attack by low concentrations of E. coli hemolysin (greater than or equal to 0.05 hemolytic units/ml; greater than or equal to 5 ng/ml). Sublytic amounts of hemolysin increased the permeability of endothelial cell monolayers in a time- and dose-dependent manner. The hydraulic conductivity increased approximately 30-fold and the reflection coefficient for large molecules dropped from 0.71 to less than 0.05, indicating a toxin-induced loss of endothelial barrier function. The alterations of endothelial monolayer permeability were accompanied by cell retraction and interendothelial gap formation. In addition, E. coli hemolysin stimulated prostacyclin synthesis in endothelial cells. This effect was strictly dependent on the presence of extracellular Ca2+ but not of Mg2+. An enhanced passive influx of 45Ca2+ and 3H-sucrose but not of tritiated inulin and dextran was noted in toxin-treated cells, indicating that small transmembrane pores comparable to those detected in rabbit erythrocytes had been generated in endothelial cell membranes. These pores may act as nonphysiologic Ca2+ gates, thereby initiating different Ca2+-dependent cellular processes. We conclude that endothelial cells are highly susceptible to E. coli hemolysin and that two major endothelial cell functions are altered by very low concentrations of hemolysin. Images PMID:2121650

  1. Insights from 100 Years of Research with Probiotic E. Coli.

    PubMed

    Wassenaar, Trudy M

    2016-09-29

    A century ago, Alfred Nissle discovered that intentional intake of particular strains of Escherichia coli could treat patients suffering from infectious diseases. Since then, one of these strains became the most frequently used probiotic E. coli in research and was applied to a variety of human conditions. Here, properties of that E. coli Nissle 1917 strain are compared with other commercially available E. coli probiotic strains, with emphasis on their human applications. A literature search formed the basis of a summary of research findings reported for the probiotics Mutaflor, Symbioflor 2, and Colinfant. The closest relatives of the strains in these products are presented, and their genetic content, including the presence of virulence, genes is discussed. A similarity to pathogenic strains causing urinary tract infections is noticeable. Historic trends in research of probiotics treatment for particular human conditions are identified. The future of probiotic E. coli may lay in what Alfred Nissle originally discovered: to treat gastrointestinal infections, which nowadays are often caused by antibiotic-resistant pathogens.

  2. The Genetic Basis of Escherichia coli Pathoadaptation to Macrophages

    PubMed Central

    Miskinyte, Migla; Sousa, Ana; Ramiro, Ricardo S.; de Sousa, Jorge A. Moura; Kotlinowski, Jerzy; Caramalho, Iris; Magalhães, Sara; Soares, Miguel P.; Gordo, Isabel

    2013-01-01

    Antagonistic interactions are likely important driving forces of the evolutionary process underlying bacterial genome complexity and diversity. We hypothesized that the ability of evolved bacteria to escape specific components of host innate immunity, such as phagocytosis and killing by macrophages (MΦ), is a critical trait relevant in the acquisition of bacterial virulence. Here, we used a combination of experimental evolution, phenotypic characterization, genome sequencing and mathematical modeling to address how fast, and through how many adaptive steps, a commensal Escherichia coli (E. coli) acquire this virulence trait. We show that when maintained in vitro under the selective pressure of host MΦ commensal E. coli can evolve, in less than 500 generations, virulent clones that escape phagocytosis and MΦ killing in vitro, while increasing their pathogenicity in vivo, as assessed in mice. This pathoadaptive process is driven by a mechanism involving the insertion of a single transposable element into the promoter region of the E. coli yrfF gene. Moreover, transposition of the IS186 element into the promoter of Lon gene, encoding an ATP-dependent serine protease, is likely to accelerate this pathoadaptive process. Competition between clones carrying distinct beneficial mutations dominates the dynamics of the pathoadaptive process, as suggested from a mathematical model, which reproduces the observed experimental dynamics of E. coli evolution towards virulence. In conclusion, we reveal a molecular mechanism explaining how a specific component of host innate immunity can modulate microbial evolution towards pathogenicity. PMID:24348252

  3. Unusual "flesh-eating" strains of Escherichia coli.

    PubMed

    Shaked, Hila; Samra, Zmira; Paul, Michal; Madar-Shapiro, Liora; Cohen, Jonathan; Pitlik, Silvio; Bishara, Jihad

    2012-12-01

    Monomicrobial necrotizing fasciitis (type II) is typically caused by group A streptococcus alone or in combination with Staphylococcus aureus. Escherichia coli has been isolated from polymicrobial or Fournier's gangrene but has rarely been reported in monomicrobial necrotizing fasciitis. We describe the clinical characteristics and outcomes of seven cases of monomicrobial E. coli necrotizing fasciitis and/or severe soft tissue infection diagnosed at a single institution during an 18-month period. Four isolates from three patients and two isolates from two patients with type I polymicrobial severe soft tissue infection (controls) were assayed by the randomly amplified polymorphic DNA (RAPD) analysis for fingerprinting and PCR amplification of primers in order to detect cytotoxic necrotizing factor 1 and 2 (cnf1 and cnf2) genes. All patients had some type of immune suppression. The limb was the most commonly involved organ. In all cases, E. coli was isolated as a monomicrobial pathogen from blood, fascia, or both. All patients died during hospitalization, three within the first 48 h. The RAPD amplification assay showed a high degree of genetic diversity among the "flesh-eating" strains and controls. The cnf1 toxin gene was identified in two out of three cases, but not in the controls. cnf2 was not detected in any of the patients. E. coli may be responsible for life-threatening necrotizing fasciitis. Further research is needed to reveal relevant risk factors, reservoirs, and modes of transmission of cnf1 E. coli.

  4. Escherichia coli exports cyclic AMP via TolC.

    PubMed

    Hantke, Klaus; Winkler, Karin; Schultz, Joachim E

    2011-03-01

    In Escherichia coli more than 180 genes are regulated by the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex. However, more than 90% of cAMP that is made by intracellular adenylyl cyclases is found in the culture medium. How is cAMP exported from E. coli? In a tolC mutant, 0.03 mM IPTG (isopropyl-β-d-thiogalactopyranoside) was sufficient to induce β-galactosidase compared to 0.1 mM IPTG in the parent strain. In a cya mutant unable to produce cAMP about 1 mM extracellular cAMP was required to induce β-galactosidase, whereas in a cya tolC mutant 0.1 mM cAMP was sufficient. When cAMP in E. coli cya was generated intracellularly by a recombinant, weakly active adenylyl cyclase from Corynebacterium glutamicum, the critical level of cAMP necessary for induction of maltose degradation was only achieved in a tolC mutant and not in the parent strain. Deletion of a putative cAMP phosphodiesterase of E. coli, CpdA, resulted in a slightly similar, yet more diffuse phenotype. The data demonstrate that export of cAMP via TolC is a most efficient way of E. coli to lower high concentrations of cAMP in the cell and maintain its sensitivity in changing metabolic environments.

  5. Selective detection of Escherichia coli DNA using fluorescent carbon spindles.

    PubMed

    Roy, Anurag; Chatterjee, Sabyasachi; Pramanik, Srikrishna; Devi, Parukuttyamma Sujatha; Suresh Kumar, Gopinatha

    2016-04-28

    We investigate the interaction of hydrophilic blue emitting carbon spindles with various deoxyribonucleic acids (DNA) having different base pair compositions, such as Herring testes (HT), calf thymus (CT), Escherichia coli (EC) and Micrococcus lysodeikticus (ML) DNA, to understand the mode of interaction. Interestingly, the fluorescent carbon spindles selectively interacted with E. coli DNA resulting in enhanced fluorescence of the former. Interaction of the same carbon with other DNAs exhibited insignificant changes in fluorescence. In addition, in the presence of EC DNA, the D band in the Raman spectrum attributed to the defect state completely disappeared, resulting in enhanced crystallinity. Microscopy images confirmed the wrapping of DNA on the carbon spindles leading to the assembly of spindles in the form of flowers. Dissociation of double-stranded DNA occurred upon interaction with carbon spindles, resulting in selective E. coli DNA interaction. The carbon spindles also exhibited a similar fluorescence enhancement upon treating with E. coli bacteria. These results confirm the possibility of E. coli detection in water and other liquid foods using such fluorescent carbon.

  6. Salmonella typhimurium intercepts Escherichia coli signaling to enhance antibiotic tolerance

    PubMed Central

    Vega, Nicole M.; Allison, Kyle R.; Samuels, Amanda N.; Klempner, Mark S.; Collins, James J.

    2013-01-01

    Bacterial communication plays an important role in many population-based phenotypes and interspecies interactions, including those in host environments. These interspecies interactions may prove critical to some infectious diseases, and it follows that communication between pathogenic bacteria and commensal bacteria is a subject of growing interest. Recent studies have shown that Escherichia coli uses the signaling molecule indole to increase antibiotic tolerance throughout its population. Here, we show that the intestinal pathogen Salmonella typhimurium increases its antibiotic tolerance in response to indole, even though S. typhimurium does not natively produce indole. Increased antibiotic tolerance can be induced in S. typhimurium by both exogenous indole added to clonal S. typhimurium populations and indole produced by E. coli in mixed-microbial communities. Our data show that indole-induced tolerance in S. typhimurium is mediated primarily by the oxidative stress response and, to a lesser extent, by the phage shock response, which were previously shown to mediate indole-induced tolerance in E. coli. Further, we find that indole signaling by E. coli induces S. typhimurium antibiotic tolerance in a Caenorhabditis elegans model for gastrointestinal infection. These results suggest that the intestinal pathogen S. typhimurium can intercept indole signaling from the commensal bacterium E. coli to enhance its antibiotic tolerance in the host intestine. PMID:23946425

  7. Nonthermal atmospheric argon plasma jet effects on Escherichia coli biomacromolecules.

    PubMed

    Hosseinzadeh Colagar, Abasalt; Memariani, Hamed; Sohbatzadeh, Farshad; Valinataj Omran, Azadeh

    2013-12-01

    Nonthermal atmospheric plasma jet, a promising technology based on ionized gas at low temperatures, can be applied for disinfection of contaminated surfaces. In this study, Escherichia coli cells and their macromolecules were exposed to the nonthermal atmospheric argon plasma jet for different time durations. Total protein, genomic DNA, and malondialdehyde (MDA) levels of E. coli were assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining; agarose gel electrophoresis; and measurement of absorbance at 534 nm, respectively. After exposure, the spectroscopic results of liquid samples indicated that the survival reduction of E. coli can reach to 100 % in an exposure time of 600 s. Moreover, inactivation zones of E. coli, DNA degradation, and MDA levels were significantly increased. Additionally, banding patterns of total protein were changed and amino acid concentrations increased following ninhydrin test. The experimental results suggest that the nonthermal plasma could serve as an effective instrument for both sterilizing E. coli and degrading macromolecules from the surface of the objects being sterilized.

  8. Paper-based ELISA to rapidly detect Escherichia coli.

    PubMed

    Shih, Cheng-Min; Chang, Chia-Ling; Hsu, Min-Yen; Lin, Jyun-Yu; Kuan, Chen-Meng; Wang, Hsi-Kai; Huang, Chun-Te; Chung, Mu-Chi; Huang, Kui-Chou; Hsu, Cheng-En; Wang, Chun-Yuan; Shen, Ying-Cheng; Cheng, Chao-Min

    2015-12-01

    Escherichia coli is a generic indicator of fecal contamination, and certain serotypes cause food- and water-borne illness such as O157:H7. In the clinic, detection of bacteriuria, which is often due to E. coli, is critical before certain surgical procedures or in cases of nosocomial infection to prevent further adverse events such as postoperative infection or sepsis. In low- and middle-income countries, where insufficient equipment and facilities preclude modern methods of detection, a simple, low-cost diagnostic device to detect E. coli in water and in the clinic will have significant impact. We have developed a simple paper-based colorimetric platform to detect E. coli contamination in 5h. On this platform, the mean color intensity for samples with 10(5)cells/mL is 0.118±0.002 (n=4), and 0.0145±0.003 (P<0.01⁎⁎) for uncontaminated samples. This technique is less time-consuming, easier to perform, and less expensive than conventional methods. Thus, paper-based ELISA is an innovative point-of-care diagnostic tool to rapidly detect E. coli, and possibly other pathogens when customized as appropriate, especially in areas that lack advanced clinical equipment.

  9. Pulsed-Plasma Disinfection of Water Containing Escherichia coli

    NASA Astrophysics Data System (ADS)

    Satoh, Kohki; MacGregor, Scott J.; Anderson, John G.; Woolsey, Gerry A.; Fouracre, R. Anthony

    2007-03-01

    The disinfection of water containing the microorganism, Escherichia coli (E. coli) by exposure to a pulsed-discharge plasma generated above the water using a multineedle electrode (plasma-exposure treatment), and by sparging the off-gas of the pulsed plasma into the water (off-gas-sparging treatment), is performed in the ambient gases of air, oxygen, and nitrogen. For the off-gas-sparging treatment, bactericidal action is observed only when oxygen is used as the ambient gas, and ozone is found to generate the bactericidal action. For the plasma-exposure treatment, the density of E. coli bacteria decreases exponentially with plasma-exposure time for all the ambient gases. It may be concluded that the main contributors to E. coli inactivation are particle species produced by the pulsed plasma. For the ambient gases of air and nitrogen, the influence of acidification of the water in the system, as a result of pulsed-plasma exposure, may also contribute to the decay of E. coli density.

  10. Insights from 100 Years of Research with Probiotic E. Coli

    PubMed Central

    2016-01-01

    A century ago, Alfred Nissle discovered that intentional intake of particular strains of Escherichia coli could treat patients suffering from infectious diseases. Since then, one of these strains became the most frequently used probiotic E. coli in research and was applied to a variety of human conditions. Here, properties of that E. coli Nissle 1917 strain are compared with other commercially available E. coli probiotic strains, with emphasis on their human applications. A literature search formed the basis of a summary of research findings reported for the probiotics Mutaflor, Symbioflor 2, and Colinfant. The closest relatives of the strains in these products are presented, and their genetic content, including the presence of virulence, genes is discussed. A similarity to pathogenic strains causing urinary tract infections is noticeable. Historic trends in research of probiotics treatment for particular human conditions are identified. The future of probiotic E. coli may lay in what Alfred Nissle originally discovered: to treat gastrointestinal infections, which nowadays are often caused by antibiotic-resistant pathogens. PMID:27766164

  11. Escherichia coli isolated from feces of brown bears (Ursus arctos) have a lower prevalence of human extraintestinal pathogenic E. coli virulence-associated genes.

    PubMed

    Vadnov, Maruša; Barbič, Damjana; Žgur-Bertok, Darja; Erjavec, Marjanca Starčič

    2017-01-01

    Eighty-six Escherichia coli strains from feces of either wild brown bears or those living in a zoo were screened for phylogenetic groups using the revisited Clermont phylotyping method and the prevalence of 24 virulence-associated genes (VAGs) of extraintestinal pathogenic E. coli (ExPEC). Our results showed that most strains of E. coli in bears belonged to phylogenetic groups III/IV/V (29%) and B1 (26%). Only half of the tested VAGs were found in the E. coli bear strains, with fimH present in 72%, ompT in 63%, and kpsMT in 43% of the strains. When the data obtained on the fecal E. coli strains from brown bears were compared with the data obtained on 90 fecal E. coli strains from healthy humans, there were significant differences in E. coli population structures between both hosts.

  12. Infection by verocytotoxin-producing Escherichia coli.

    PubMed Central

    Karmali, M A

    1989-01-01

    Verocytotoxin (VT)-producing Escherichia coli (VTEC) are a newly recognized group of enteric pathogens which are increasingly being recognized as common causes of diarrhea in some geographic settings. Outbreak studies indicate that most patients with VTEC infection develop mild uncomplicated diarrhea. However, a significant risk of two serious and potentially life-threatening complications, hemorrhagic colitis and the hemolytic uremic syndrome, makes VTEC infection a public health problem of serious concern. The main reservoirs of VTEC appear to be the intestinal tracts of animals, and foods of animal (especially bovine) origin are probably the principal sources for human infection. The term VT refers to a family of subunit exotoxins with high biological activity. Individual VTEC strains elaborate one or both of at least two serologically distinct, bacteriophage-mediated VTs (VT1 and VT2) which are closely related to Shiga toxin and are thus also referred to as Shiga-like toxins. The holotoxins bind to cells, via their B subunits, to a specific receptor which is probably the glycolipid, globotriosyl ceramide (Gb3). Binding is followed by internalization of the A subunit, which, after it is proteolytically nicked and reduced to the A1 fragment, inhibits protein synthesis in mammalian cells by inactivating 60S ribosomal subunits through selective structural modification of 28S ribosomal ribonucleic acid. The mechanism of VTEC diarrhea is still controversial, and the relative roles of locally acting VT and "attaching and effacing adherence" of VTEC to the mucosa have yet to be resolved. There is increasing evidence that hemolytic uremic syndrome and possibly hemorrhagic colitis result from the systemic action of VT on vascular endothelial cells. The role of antitoxic immunity in preventing the systemic complications of VTEC infection is being explored. Antibiotics appear to be contraindicated in the treatment of VTEC infection. The most common VTEC serotype associated

  13. Characterization of Escherichia coli O157:H7 and other Shiga toxin-producing E. coli serotypes isolated from sheep.

    PubMed Central

    Kudva, I T; Hatfield, P G; Hovde, C J

    1997-01-01

    The isolation and characterization of Escherichia coli O157:H7 and non-O157 Shiga toxin-producing E. coli (STEC) strains from sheep are described. One flock was investigated for E. coli O157:H7 over a 16-month period that spanned two summer and two autumn seasons. Variation in the occurrence of E. coli O157:H7-positive sheep was observed, with animals being culture positive only in the summer months but not in the spring, autumn, or winter. E. coli O157:H7 isolates were distinguished by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA and toxin gene restriction fragment length polymorphism (RFLP) analysis. Ten PFGE patterns and five RFLP patterns, identified among the isolates, showed that multiple E. coli O157:H7 strains were isolated from one flock, that a single animal simultaneously shed multiple E. coli O157:H7 strains, and that the strains shed by individuals changed over time. E. coli O157:H7 was isolated only by selective enrichment culture off 10 g of ovine feces. In contrast, strains of eight STEC serotypes other than O157:H7 were cultured from feces of sheep from a separate flock without enrichment. The predominant non-O157 STEC serotype found was O91:NM (NM indicates nonmotile), and others included O128:NM, O88:NM, O6:H49, and O5:NM. Irrespective of serotype, 98% of the ovine STEC isolates possessed various combinations of the virulence-associated genes for Shiga toxin(s) and the attaching-and-effacing lesion (stx1, stx2, and eae), suggesting their potential for human pathogenicity. The most common toxin-eae genotype was positive for stx1, stx2, and eae. A Vero cell cytotoxicity assay demonstrated that 90% of the representative STEC isolates tested expressed the toxin gene. The report demonstrates that sheep transiently shed a variety of STEC strains, including E. coli O157:H7, that have potential as human pathogens. PMID:9157149

  14. Genetic Relatedness Among Escherichia coli Pathotypes Isolated from Food Products for Human Consumption in Cartagena, Colombia.

    PubMed

    Amézquita-Montes, Zorangel; Tamborski, Maria; Kopsombut, Usa G; Zhang, Chengxian; Arzuza, Octavio S; Gómez-Duarte, Oscar G

    2015-05-01

    Foodborne pathogens are a leading cause of mild-to-severe gastrointestinal illnesses worldwide. Escherichia coli pathotypes have been known to cause gastrointestinal illnesses in children less than 5 years old in Colombia. However, insufficient information is available on the prevalence of E. coli contamination of food products and the kind of E. coli food product reservoirs. The two objectives of this study were designed to address this issue. The first objective was to ascertain coliform, E. coli, and pathogenic E. coli contamination of food products readily available for human consumption in Cartagena, Colombia. The second objective was to evaluate the relationship between pathogenic E. coli isolated from food products and those isolated from cases of diarrhea in children. Food product samples consisting of pasteurized milk, unpasteurized fruit juice, ground beef, cheese, and vegetables were obtained at four retail stores. The food samples were cultured in liquid media and tested for the presence of coliforms and E. coli. E. coli isolates were tested by polymerase chain reaction for the presence of pathogenic E. coli. Coliforms, E. coli, and E. coli intestinal pathotypes contamination were detected in 88.4%, 53%, and 2.1% of food product samples, respectively. Ground beef and cheese were the only food samples contaminated with E. coli intestinal pathotypes including enteropathogenic (EPEC), Shiga toxin-producing (STEC), and enterotoxigenic E. coli (ETEC). Closed multilocus sequencing typing relationships between diarrheagenic E. coli isolates from food products and from individuals with diarrhea suggest that food products readily available at public markets in Cartagena can transmit ETEC and possibly EPEC and STEC. We demonstrated that a high proportion of food products for human consumption available at public markets in Cartagena are contaminated with coliforms, E. coli, and E. coli intestinal pathogens. Furthermore, food products containing E. coli intestinal

  15. Genetic Relatedness Among Escherichia coli Pathotypes Isolated from Food Products for Human Consumption in Cartagena, Colombia

    PubMed Central

    Amézquita-Montes, Zorangel; Tamborski, Maria; Kopsombut, Usa G.; Zhang, Chengxian; Arzuza, Octavio S.

    2015-01-01

    Abstract Foodborne pathogens are a leading cause of mild-to-severe gastrointestinal illnesses worldwide. Escherichia coli pathotypes have been known to cause gastrointestinal illnesses in children less than 5 years old in Colombia. However, insufficient information is available on the prevalence of E. coli contamination of food products and the kind of E. coli food product reservoirs. The two objectives of this study were designed to address this issue. The first objective was to ascertain coliform, E. coli, and pathogenic E. coli contamination of food products readily available for human consumption in Cartagena, Colombia. The second objective was to evaluate the relationship between pathogenic E. coli isolated from food products and those isolated from cases of diarrhea in children. Food product samples consisting of pasteurized milk, unpasteurized fruit juice, ground beef, cheese, and vegetables were obtained at four retail stores. The food samples were cultured in liquid media and tested for the presence of coliforms and E. coli. E. coli isolates were tested by polymerase chain reaction for the presence of pathogenic E. coli. Coliforms, E. coli, and E. coli intestinal pathotypes contamination were detected in 88.4%, 53%, and 2.1% of food product samples, respectively. Ground beef and cheese were the only food samples contaminated with E. coli intestinal pathotypes including enteropathogenic (EPEC), Shiga toxin–producing (STEC), and enterotoxigenic E. coli (ETEC). Closed multilocus sequencing typing relationships between diarrheagenic E. coli isolates from food products and from individuals with diarrhea suggest that food products readily available at public markets in Cartagena can transmit ETEC and possibly EPEC and STEC. We demonstrated that a high proportion of food products for human consumption available at public markets in Cartagena are contaminated with coliforms, E. coli, and E. coli intestinal pathogens. Furthermore, food products containing E. coli

  16. [Escherichia coli, a pathogen under fire from the news].

    PubMed

    Cohen, R; Raymond, J; Gendrel, D; Bingen, E

    2012-11-01

    Escherichia coli is both a gastrointestinal tract commensal and a major pathogen. In recent years, E. coli is under fire from the news due to a better understanding of pathogenic factors, outbreaks of infections caused by enterohaemorrhagic strains, and last but not least, the worrying development of antibiotic resistance. Due to the absence of new compounds active against these strains, producing extended-spectrum ß-lactamases (ESBL) and frequently multiresistant to other antibiotics, their emergence will pose therapeutic problems for practitioners of all pediatric specialties. The gold standard treatment for severe infections due to ESBL-E. coli family is the penem class. The frequent use of penems promotes the emergence of strains resistant to carbapenems. Sparing carbapenems should be a clear objective for non life-threatening infections.

  17. Campylobacter coli infection in pet birds in southern Italy.

    PubMed

    Dipineto, Ludovico; Borrelli, Luca; Pace, Antonino; Romano, Violante; D'Orazio, Stefano; Varriale, Lorena; Russo, Tamara Pasqualina; Fioretti, Alessandro

    2017-01-06

    Avian species are considered as the main reservoir of Campylobacter spp. However, few data are available on the presence of this microorganism in pet birds. This study was therefore performed to determine the prevalence of Campylobacter spp. in pet birds bred in southern Italy. Faecal samples were collected from 88 cages housing different species of pet birds and examined by bacteriological culture and polymerase chain reaction. A total of 13.6% of the cage samples were positive for Campylobacter coli. Other Campylobacter spp. were not found. The study shows that C. coli can be isolated from the cages of apparently healthy pet birds, which should therefore be considered as potential carriers of C. coli and a possible source of infection for humans and companion animals.

  18. Polyerositis and Arthritis Due to Escherichia coli in Gnotobiotic Pigs

    PubMed Central

    Waxler, G. L.; Britt, A. L.

    1972-01-01

    Forty gnotobiotic pigs from six litters were exposed orally to Escherichia coli 083:K·:NM at 69 to 148 hours of age, while 17 pigs from the same litters served as unexposed controls. Clinical signs of infection included fever, anorexia, diarrhea, lameness, and reluctance to move. Eighty-four percent of the exposed pigs in four litters died, while only 13% in two litters died. Gross and microscopic lesions included serofibrinous to fibrinopurulent polyserositis in 96% of the exposed pigs in four litters and 33% of the exposed pigs in two litters. A few pigs had gross and/or microscopic lesions of arthritis. Escherichia coli was routinely isolated from the serous and synovial cavities of infected pigs. Anti-hog cholera serum administered orally as a colostrum substitute gave partial protection against E. coli infection. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5.Fig. 6.Fig. 7.Fig. 8. PMID:4261837

  19. Functions of the gene products of Escherichia coli.

    PubMed Central

    Riley, M

    1993-01-01

    A list of currently identified gene products of Escherichia coli is given, together with a bibliography that provides pointers to the literature on each gene product. A scheme to categorize cellular functions is used to classify the gene products of E. coli so far identified. A count shows that the numbers of genes concerned with small-molecule metabolism are on the same order as the numbers concerned with macromolecule biosynthesis and degradation. One large category is the category of tRNAs and their synthetases. Another is the category of transport elements. The categories of cell structure and cellular processes other than metabolism are smaller. Other subjects discussed are the occurrence in the E. coli genome of redundant pairs and groups of genes of identical or closely similar function, as well as variation in the degree of density of genetic information in different parts of the genome. PMID:7508076

  20. Incidence of Escherichia coli in Black Walnut Meats

    PubMed Central

    Meyer, Melvin T.; Vaughn, Reese H.

    1969-01-01

    Examination of commercially shelled black walnut meats showed inconsistent numbers of total aerobic bacteria, coliforms, and Escherichia coli; variation occurred among different meat sizes and within each meat size. The incidence of E. coli on meats of commercially hulled black walnuts depended on the physical condition of the nuts. Apparently tightly sealed ones contained only a few or none, whereas those with visibly separated sutures and spoiled meats yielded the most. This contamination was in part correlated to a hulling operation. Large numbers of E. coli on the husk of the walnuts contaminated the hulling water, subsequently also contaminating the meats by way of separated sutures. Chlorination of the hulling wash water was ineffective. Attempts were made to decontaminate the walnut meats without subsequent deleterious changes in flavor or texture. A treatment in coconut oil at 100 C followed by removal of excess surface oil by centrifugation was best. PMID:4905608

  1. Evolution of E. coli tRNA(Trp)

    NASA Technical Reports Server (NTRS)

    Staves, Mark P.; Lacey, James C., Jr.; Bloch, David P.

    1988-01-01

    It has been shown by Lacey et al. (1985) that, in general, the hydrophobicity ranking of an amino acid correlates with that of its anticodonic nucleotide, with tryptophan being one of the four amino acids for which this rule does not apply. It was proposed that this failure to correlate was due to the fact that the anticodon assignments for the four amino acids were made late, after the mutation of existing tRNAs. In this paper, the evolution of E. coli tRNA(Trp) is examined by comparing its homology with other E. coli tRNAs. The results demonstrate the presence of an evolutionary relationship between E. coli tRNA(Trp) and tRNA(Gly) or tRNA(Arg) molecules, and support the idea of the late assignment of anticodon to Trp.

  2. Quantitative method for enumeration of enterotoxigenic Escherichia coli.

    PubMed Central

    Calderon, R L; Levin, M A

    1981-01-01

    A rapid method was developed to quantify toxigenic Escherichia coli, using a membrane filter procedure. After filtration of samples, the membrane filter was first incubated on a medium selective for E. coli (24 h, 44 degrees C) and then transferred to tryptic soy agar (3%; 6 h, 37 degrees C). To assay for labile toxin-producing colonies, the filter was then transferred to a monolayer of Y-1 cells, the E. coli colonies were marked on the bottom of the petri dish, and the filter was removed after 15 min. The monolayer was observed for a positive rounding effect after a 15- to 24-h incubation. The method has an upper limit of detecting 30 toxigenic colonies per plate and can detect as few as one toxigenic colony per plate. A preliminary screening for these enterotoxigenic strains in polluted waters and known positive fecal samples was performed, and positive results were obtained with fecal samples only. PMID:7007415

  3. Mechanisms of the radioprotective effect of cysteamine in Escherichia coli

    SciTech Connect

    Korystov, Yu.N.; Vexler, F.B.

    1988-06-01

    The values of the oxygen effect (m) and the maximal protective effect of cysteamine (DMF*) were estimated for four Escherichia coli strains: AB1157 (wild type), AB1886 (uvrA), AB2463 (recA), and p3478 (polA). A correlation made between DMF* and m as well as the kinetics of the increase of DMF with oxygen depletion showed that the protective effect of cysteamine is realized by three mechanisms: (i) anoxia achieved by oxygen reduction, with the DMF varying from 2.2 to 4.2 for different E. coli strains (this protection is the major contribution to the entire mechanism); (ii) lowering of the indirect radiation effect; i.e., for 50 mM cysteamine DMF does not exceed 1.1; and (iii) increase of the efficiency of enzymatic repair. The latter effect of cysteamine is registered only with the wild-type E. coli, the DMF being not less than 1.4.

  4. Chemotaxis towards autoinducer 2 mediates autoaggregation in Escherichia coli

    PubMed Central

    Laganenka, Leanid; Colin, Remy; Sourjik, Victor

    2016-01-01

    Bacteria communicate by producing and sensing extracellular signal molecules called autoinducers. Such intercellular signalling, known as quorum sensing, allows bacteria to coordinate and synchronize behavioural responses at high cell densities. Autoinducer 2 (AI-2) is the only known quorum-sensing molecule produced by Escherichia coli but its physiological role remains elusive, although it is known to regulate biofilm formation and virulence in other bacterial species. Here we show that chemotaxis towards self-produced AI-2 can mediate collective behaviour—autoaggregation—of E. coli. Autoaggregation requires motility and is strongly enhanced by chemotaxis to AI-2 at physiological cell densities. These effects are observed regardless whether cell–cell interactions under particular growth conditions are mediated by the major E. coli adhesin (antigen 43) or by curli fibres. Furthermore, AI-2-dependent autoaggregation enhances bacterial stress resistance and promotes biofilm formation. PMID:27687245

  5. Engineering Escherichia coli K12 MG1655 to use starch

    PubMed Central

    2014-01-01

    Background To attain a sustainable bioeconomy, fuel, or valuable product, production must use biomass as substrate. Starch is one of the most abundant biomass resources and is present as waste or as a food and agroindustry by-product. Unfortunately, Escherichia coli, one of the most widely used microorganisms in biotechnological processes, cannot use starch as a carbon source. Results We engineered an E. coli strain capable of using starch as a substrate. The genetic design employed the native capability of the bacterium to use maltodextrins as a carbon source plus expression and secretion of its endogenous α-amylase, AmyA, in an adapted background. Biomass production improved using 35% dissolved oxygen and pH 7.2 in a controlled bioreactor. Conclusion The engineered E. coli strain can use starch from the milieu and open the possibility of optimize the process to use agroindustrial wastes to produce biofuels and other valuable chemicals. PMID:24886307

  6. Persistence of Escherichia coli O157 and non-O157 strains in agricultural soils.

    PubMed

    Ma, Jincai; Mark Ibekwe, A; Crowley, David E; Yang, Ching-Hong

    2014-08-15

    Shiga toxin producing Escherichia coli O157 and non-O157 serogroups are known to cause serious diseases in human. However, research on the persistence of E. coli non-O157 serogroups in preharvest environment is limited. In the current study, we compared the survival behavior of E. coli O157 to that of non-O157 E. coli strains in agricultural soils collected from three major fresh produce growing areas of California (CA) and Arizona (AZ). Results showed that the nonpathogenic E. coli O157:H7 4554 survived longer than the pathogenic E. coli O157:H7 EDL933 in Imperial Valley CA and Yuma AZ, but not in soils from the Salinas area. However, E. coli O157:NM was found to persist significantly longer than E. coli O157:H7 EDL933 in all soil tested from the three regions. Furthermore, two non-O157 (E. coli O26:H21 and E. coli O103:H2) survived significantly longer than E. coli O157:H7 EDL933 in all soils tested. Pearson correlation analysis showed that survival of the E. coli strains was affected by different environmental factors. Our data suggest that survival of E. coli O157 and non-O157 may be strain and soil specific, and therefore, care must be taken in data interpretation with respect to survival of this pathogen in different soils.

  7. [Development of chromogenic agar medium for isolation of enterohaemorrhagic Escherichia coli O26].

    PubMed

    Ikedo, M; Komatsu, O; Hara-Kudo, Y; Yamamoto, S; Kumagai, S

    2001-04-01

    Agar media for isolation of enterohaemorrhagic Escherichia coli (EHEC) have been developed primarily for E. coli O157, because this bacterium has most frequently caused EHEC infection. However, there have been few studies for isolation of other serotypes of EHEC, and media appropriate for isolation of such organisms, especially from food samples, are not yet available. Among such serotypes, E. coli O26 has often been isolated from clinical specimens from patients and animals, but not from food samples in outbreaks, because of lack of an appropriate method for isolation. In this study, we tried to develop a new chromogenic agar medium for selective isolation of E. coli O26 using the characteristics of E. coli O26. Fifteen strains of E. coli O26, 11 strains of E. coli O157 and 36 strains of other sero-types E. coli were tested for fermentation of rhamnose, cellobiose, dulcitol, salicin, raffinose, sorbitol, sucrose, lactose, mannitol, arabinose, maltose, xylose and glucose. Rhamnose was fermented by all E. coli strains except for E. coli O26. The other substrates were not effective for differentiating E. coli O26 from the other strains of E. coli. Thus the medium containing rhamnose and 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside, which is a substrate of beta-galactosidase specific to coliforms, produced a color of E. coli O26 colonies different from colors of the other bacteria. Furthermore, cefixime and sodium tellulite were added to the composition of the medium for gaining higher selectivity.

  8. Occurrence of Escherichia coli, Campylobcter, Salmonella and Shiga-Toxin Producing E. coli in Norwegian Primary Strawberry Production.

    PubMed

    Johannessen, Gro S; Eckner, Karl F; Heiberg, Nina; Monshaugen, Marte; Begum, Mumtaz; Økland, Marianne; Høgåsen, Helga R

    2015-06-17

    The aim of this study was to investigate the bacteriological quality of strawberries at harvest and to study risk factors such as irrigation water, soil and picker's hand cleanliness. Four farms were visited during the harvest season in 2012. Samples of strawberries, irrigation water, soil and hand swabs were collected and analyzed for E. coli, Campylobacter, Salmonella and STEC Although fecal indicators and pathogens were found in environmental samples, only one of 80 samples of strawberries was positive for E. coli (1.0 log10 cfu/g) and pathogens were not detected in any of the strawberry samples. The water samples from all irrigation sources were contaminated with E. coli in numbers ranging from 0 to 3.3 log10 cfu/g. Campylobacter (8/16 samples) and Salmonella (1/16 samples) were isolated from samples with high numbers of E. coli. The water samples collected from a lake had lower numbers of E. coli than the samples from rivers and a stream. The present study indicated continuous background contamination in the primary production environment. Although the background contamination was not reflected on the strawberries tested here, the results must be interpreted with caution due to the limited number of samples.

  9. Occurrence of Escherichia coli, Campylobcter, Salmonella and Shiga-Toxin Producing E. coli in Norwegian Primary Strawberry Production

    PubMed Central

    Johannessen, Gro S.; Eckner, Karl F.; Heiberg, Nina; Monshaugen, Marte; Begum, Mumtaz; Økland, Marianne; Høgåsen, Helga R.

    2015-01-01

    The aim of this study was to investigate the bacteriological quality of strawberries at harvest and to study risk factors such as irrigation water, soil and picker’s hand cleanliness. Four farms were visited during the harvest season in 2012. Samples of strawberries, irrigation water, soil and hand swabs were collected and analyzed for E. coli, Campylobacter, Salmonella and STEC Although fecal indicators and pathogens were found in environmental samples, only one of 80 samples of strawberries was positive for E. coli (1.0 log10 cfu/g) and pathogens were not detected in any of the strawberry samples. The water samples from all irrigation sources were contaminated with E. coli in numbers ranging from 0 to 3.3 log10 cfu/g. Campylobacter (8/16 samples) and Salmonella (1/16 samples) were isolated from samples with high numbers of E. coli. The water samples collected from a lake had lower numbers of E. coli than the samples from rivers and a stream. The present study indicated continuous background contamination in the primary production environment. Although the background contamination was not reflected on the strawberries tested here, the results must be interpreted with caution due to the limited number of samples. PMID:26090606

  10. Adhesive Escherichia coli in inflammatory bowel disease and infective diarrhoea.

    PubMed Central

    Burke, D. A.; Axon, A. T.

    1988-01-01

    The clinical features of ulcerative colitis and Crohn's disease are similar to those of infections of the bowel, although their cause is uncertain. Many bacteria that cause intestinal diseases adhere to the gut mucosa, and adhesion of pathogenic Escherichia coli is resistant to D-mannose. The adhesive properties of isolates of E coli were assessed by assay of adhesion to buccal epithelial cells with mannose added. The isolates were obtained from patients with inflammatory bowel diseases (50 with a relapse of ulcerative colitis, nine with ulcerative colitis in remission, 13 with Crohn's disease, and 11 with infectious diarrhoea not due to E coli) and 22 controls. The median index of adhesion to buccal epithelial cells (the proportion of cells with more than 50 adherent bacteria) for E coli from patients with ulcerative colitis in relapse was significantly higher (43%) than that for controls (5%) and patients with infectious diarrhoea (14%). The index was not significantly different among isolates from patients with ulcerative colitis in relapse, Crohn's disease (53%), and ulcerative colitis in remission (30%). If an index of adhesion of greater than 25% is taken as indicating an adhesive strain 86% of isolates of E coli from patients with inflammatory bowel disease were adhesive compared with 27% from patients with infective diarrhoea and none from controls. The adhesive properties of the isolates from patients with inflammatory bowel disease were similar to those of pathogenic intestinal E coli, raising the possibility that they may have a role in the pathogenesis of the condition; the smaller proportion of adhesive isolates in patients with infective diarrhoea due to other bacteria suggests that the organism may be of primary importance rather than arising secondarily. Images a PMID:3044496

  11. Behavior of shiga toxin-producing Escherichia coli, enteroinvasive E. coli, enteropathogenic E. coli and enterotoxigenic E. coli strains on whole and sliced jalapeño and serrano peppers.

    PubMed

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Gordillo-Martínez, Alberto J; Castro-Rosas, Javier

    2014-06-01

    The behavior of enterotoxigenic Escherichia coli (ETEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC) and non-O157 shiga toxin-producing E. coli (non-O157-STEC) on whole and slices of jalapeño and serrano peppers as well as in blended sauce at 25 ± 2 °C and 3 ± 2 °C was investigated. Chili peppers were collected from markets of Pachuca city, Hidalgo, Mexico. On whole serrano and jalapeño stored at 25 ± 2 °C or 3 ± 2 °C, no growth was observed for EPEC, ETEC, EIEC and non-O157-STEC rifampicin resistant strains. After twelve days at 25 ± 2 °C, on serrano peppers all diarrheagenic E. coli pathotypes (DEP) strains had decreased by a total of approximately 3.7 log, whereas on jalapeño peppers the strains had decreased by approximately 2.8 log, and at 3 ± 2 °C they decreased to approximately 2.5 and 2.2 log respectively, on serrano and jalapeño. All E. coli pathotypes grew onto sliced chili peppers and in blended sauce: after 24 h at 25 ± 2 °C, all pathotypes had grown to approximately 3 and 4 log CFU on pepper slices and sauce, respectively. At 3 ± 2 °C the bacterial growth was inhibited.

  12. Pathogenic Escherichia coli in rural household container waters.

    PubMed

    Jagals, P; Barnard, T G; Mokoena, M M; Ashbolt, N; Roser, D J

    2013-01-01

    Plastic containers in the range of 5-20 L are widely used - especially in rural African settings - to collect, transport and store water for domestic use, including drinking, bathing and hygiene. The pathogen content of the waters in these containers has not been adequately characterized as yet. This paper presents the primary findings of a synoptic survey of drinking water quality samples from these containers and involved collection of bacterial indicator and pathogenicity gene data. In total, 571 samples of a variety of waters were taken in rural communities in South Africa and the Escherichia coli numbers measured. Of the E. coli positive samples, 46% (n = 148) were screened for the presence of E. coli pathogen gene markers. Though synoptic, the survey provided many insights into the issues that drove the study. Container use markedly degraded water quality as judged by indicator counts, even where improved water supply services were in place. Household container use also appeared to promote regrowth or contamination of containers with pathogenic E. coli strains. Polymerase chain reaction (PCR) analysis also showed that the diversity of potential pathogenic E. coli carrying virulence genes was great. All seven genes screened for (Ial, Stx1, Stx2, EaeA, Eagg, ST, LT) were found in the waters, alone or as mixtures (number of different combinations = 31) including those characteristic of the more dangerous invasive and haemorrhagic E. coli strains. Given the central role of containers in the management of water supply to rural communities, it is clear the microbiology of these waters requires much further characterization.

  13. Dynamic regulation of extracellular ATP in Escherichia coli.

    PubMed

    Alvarez, Cora Lilia; Corradi, Gerardo; Lauri, Natalia; Marginedas-Freixa, Irene; Leal Denis, María Florencia; Enrique, Nicolás; Mate, Sabina María; Milesi, Verónica; Ostuni, Mariano Anibal; Herlax, Vanesa; Schwarzbaum, Pablo Julio

    2017-04-04

    We studied the kinetics of extracellular ATP (ATPe) in Escherichia coli and their outer membrane vesicles (OMVs) stimulated with amphipatic peptides melittin (MEL) and mastoparan 7 (MST7). Real-time luminometry was used to measure ATPe kinetics, ATP release, and ATPase activity. The latter was also determined by following [(32)P]Pi released from [γ-(32)P]ATP. E. coli was studied alone, co-incubated with Caco-2 cells, or in rat jejunum segments. In E. coli, the addition of [γ-(32)P]ATP led to the uptake and subsequent hydrolysis of ATPe. Exposure to peptides caused an acute 3-fold (MST7) and 7-fold (MEL) increase in [ATPe]. In OMVs, ATPase activity increased linearly with [ATPe] (0.1-1 µM). Exposure to MST7 and MEL enhanced ATP release by 3-7 fold, with similar kinetics to that of bacteria. In Caco-2 cells, the addition of ATP to the apical domain led to a steep [ATPe] increase to a maximum, with subsequent ATPase activity. The addition of bacterial suspensions led to a 6-7 fold increase in [ATPe], followed by an acute decrease. In perfused jejunum segments, exposure to E. coli increased luminal ATP 2 fold. ATPe regulation of E. coli depends on the balance between ATPase activity and ATP release. This balance can be altered by OMVs, which display their own capacity to regulate ATPe. E. coli can activate ATP release from Caco-2 cells and intestinal segments, a response which in vivo might lead to intestinal release of ATP from the gut lumen.

  14. Expression of a synthetic pertussis toxin operon in Escherichia coli.

    PubMed

    Pozza, T D; Yan, H; Walker, M J

    1997-06-01

    Bordetella pertussis is the causative agent of whooping cough, a severe disease of infants characterised by repeated of paroxysmal coughing. Pertussis toxin (PT) is a major virulence factor of B. pertussis and is a typical A/B bacterial toxin consisting of five subunits S1-S5 in a ratio of 1:1:1:2:1. The PT subunit genes are organized into an operon which is not expressed in Escherichia coli, thus hampering the use of this organism for vaccine production. We have expressed the five PT subunits individually in E. coli by replacing the wild-type transcriptional and translational signals, and in the case of the S4 subunit the leader peptide has been exchanged with a modified E. coli beta-lactamase leader sequence. We have developed a stepwise cloning method to construct a synthetic PT operon which simultaneously expresses the five PT subunits in E. coli. Western blot analysis indicated that in E. coli KS476 containing the synthetic PT operon, S4 and S5 were completely processed, S1 was partially processed, whilst the majority of S2 and S3 remained unprocessed. Periplasmic extracts contained soluble S1 and S3; however, the processed form of S2, S4 and S5 were not detected, suggesting that these subunits may be membrane associated or in an insoluble form. This work should allow an investigation of the potential of E. coli to produce detoxified PT in a background free of other pertussis virulence factors that may contribute to the side-effects of some vaccine preparations currently in use.

  15. A structural view of the dissociation of Escherichia coli tryptophanase.

    PubMed

    Green, Keren; Qasim, Nasrin; Gdaelvsky, Garik; Kogan, Anna; Goldgur, Yehuda; Parola, Abraham H; Lotan, Ofra; Almog, Orna

    2015-12-01

    Tryptophanase (Trpase) is a pyridoxal 5'-phosphate (PLP)-dependent homotetrameric enzyme which catalyzes the degradation of L-tryptophan. Trpase is also known for its cold lability, which is a reversible loss of activity at low temperature (2°C) that is associated with the dissociation of the tetramer. Escherichia coli Trpase dissociates into dimers, while Proteus vulgaris Trpase dissociates into monomers. As such, this enzyme is an appropriate model to study the protein-protein interactions and quaternary structure of proteins. The aim of the present study was to understand the differences in the mode of dissociation between the E. coli and P. vulgaris Trpases. In particular, the effect of mutations along the molecular axes of homotetrameric Trpase on its dissociation was studied. To answer this question, two groups of mutants of the E. coli enzyme were created to resemble the amino-acid sequence of P. vulgaris Trpase. In one group, residues 15 and 59 that are located along the molecular axis R (also termed the noncatalytic axis) were mutated. The second group included a mutation at position 298, located along the molecular axis Q (also termed the catalytic axis). Replacing amino-acid residues along the R axis resulted in dissociation of the tetramers into monomers, similar to the P. vulgaris Trpase, while replacing amino-acid residues along the Q axis resulted in dissociation into dimers only. The crystal structure of the V59M mutant of E. coli Trpase was also determined in its apo form and was found to be similar to that of the wild type. This study suggests that in E. coli Trpase hydrophobic interactions along the R axis hold the two monomers together more strongly, preventing the dissociation of the dimers into monomers. Mutation of position 298 along the Q axis to a charged residue resulted in tetramers that are less susceptible to dissociation. Thus, the results indicate that dissociation of E. coli Trpase into dimers occurs along the molecular Q axis.

  16. Recurrent Hemolytic and Uremic Syndrome Induced by Escherichia Coli

    PubMed Central

    Commereuc, Morgane; Weill, Francois-Xavier; Loukiadis, Estelle; Gouali, Malika; Gleizal, Audrey; Kormann, Raphaël; Ridel, Christophe; Frémeaux-Bacchi, Véronique; Rondeau, Eric; Hertig, Alexandre

    2016-01-01

    Abstract A widespread belief is that typical hemolytic and uremic syndrome (HUS) does not recur. We report the case of a patient infected twice with raw milk taken from his own cow and containing a Shiga toxin–producing Escherichia coli O174:H21 that induced recurrent HUS causing severe renal and cerebral disorders. A genomic comparison of the human and bovine Shiga toxin–producing Escherichia coli O174:H21 isolates revealed that they were identical. Typical HUS may recur. Since milk from this animal was occasionally distributed locally, thereby posing a serious threat for the whole village, this particular cow was destroyed. PMID:26735524

  17. Metabolic engineering of Escherichia coli for 1-butanol production.

    PubMed

    Atsumi, Shota; Cann, Anthony F; Connor, Michael R; Shen, Claire R; Smith, Kevin M; Brynildsen, Mark P; Chou, Katherine J Y; Hanai, Taizo; Liao, James C

    2008-11-01

    Compared to ethanol, butanol offers many advantages as a substitute for gasoline because of higher energy content and higher hydrophobicity. Typically, 1-butanol is produced by Clostridium in a mixed-product fermentation. To facilitate strain improvement for specificity and productivity, we engineered a synthetic pathway in Escherichia coli and demonstrated the production of 1-butanol from this non-native user-friendly host. Alternative genes and competing pathway deletions were evaluated for 1-butanol production. Results show promise for using E. coli for 1-butanol production.

  18. Functional role of bdm during flagella biogenesis in Escherichia coli.

    PubMed

    Kim, Ji-Sun; Kim, Yu Jin; Seo, Sojin; Seong, Maeng-Je; Lee, Kangseok

    2015-03-01

    The biofilm-dependent modulation gene (bdm) has recently been shown to play a role in osmotic-induced formation of biofilm in Escherichia coli. In this study, we demonstrated that deletion of bdm results in down-regulation of flagella biosynthesis genes and, consequently, a defect in E. coli motility. In addition, we employed atomic force microscopy to confirm the absence of flagella-like structures on the surface of bdm-null cells. These findings indicate that bdm plays a key role in regulatory pathway for the formation of flagella.

  19. Unidirecetional motility of excherichia coli in restrictive capillaries

    SciTech Connect

    Liu, Z.; Papadopoulos, K.D.

    1995-10-01

    In a 6-{mu}m capillary filled with buffer and in the absence of any chemotactic stimuli, Escherichia coli K-12 cells swim persistently in only one direction. This behavior of E. coli can be simply explained by means of the length and relative rigidity of their flagella. Single-cell motility parameters-swimming speed, turn angle, and run length time-were measured. Compared with the motility parameters measured in bulk phase, turn angle was influenced because of the effect of the geometrical restriction. 30 refs., 6 figs.

  20. PROPERTIES OF A BACTERIOPHAGE DERIVED FROM ESCHERICHIA COLI K235

    PubMed Central

    Jesaitis, Margeris A.; Hutton, John J.

    1963-01-01

    A temperate bacteriophage was isolated from the colicinogenic strain of Escherichia coli K235 and characterized. This phage, termed PK, is related to P2 virus morphologically, serologically, and, possibly, genetically and it bears no relationship to the T-even phages. It was also demonstrated that PK virus and colicine K differ both in their host range and in their immunological specificity, and that PK prophage does not induce the colicinogenesis in its host bacterium. It was concluded that the formation of colicine K. and PK phage in E. coli K235 are controlled by different genetic determinants. PMID:14029160

  1. [Expression of Photobacterium leiognathi bioluminescence system genes in Escherichia coli].

    PubMed

    Ptitsyn, L R; Fatova, M A; Stepanov, A I

    1990-02-01

    Expression of Photobacterium leiognathi bioluminescence genes under the control of lac, tac, tet promoters in Escherichia coli cells has been studied. The position of the genes for aliphatic aldehyde biosynthesis and for the synthesis of luciferase subunits was identified. The plasmid pBRPL1 has been constructed containing the system of bioluminescence genes devoid of promoter following the polylinker DNA fragment. The plasmid can be used for selection of promoter containing DNA sequences as well as for studying the promoters regulation in process of Escherichia coli cells growth.

  2. Nitric oxide donor-mediated killing of bioluminescent Escherichia coli.

    PubMed Central

    Virta, M; Karp, M; Vuorinen, P

    1994-01-01

    The antimicrobial activities of two nitric oxide-releasing compounds against Escherichia coli were investigated by using recombinant E. coli cloned with a luciferase gene from Pyrophorus plagiophthalamus. Since luciferase uses intracellular ATP to generate visible light which can be measured from living cells in real time, we wanted to compare the extent to which cell viability parallels light emission. Results from luminescence measurements and CFU counts were in good agreement, and the decrease in light emission was shown to provide a rapid and more sensitive indication of cytotoxicity. PMID:7695261

  3. Antioxidant assay using genetically engineered bioluminescent Escherichia coli

    NASA Astrophysics Data System (ADS)

    Bartolome, Amelita; Macalino, Bernadette; Pastoral, Ian Lemuel; Sevilla, Fortunato, III

    2006-02-01

    A new antioxidant activity assay based on the reactive oxygen species (ROS)-inducible bacterial strain (E. coli DPD2511) is described. The strain harbors the plasmid pKatG::luxCDABE and responds to hydrogen peroxide treatment by increasing light emission at 490 nm. Antioxidant capacity is evaluated through the ability of an agent to inhibit the hydrogen peroxide-induced bioluminescence of E. coli DPD2511. Applicability of the developed assay in detecting levels of antioxidants in various aqueous plant extracts is demonstrated. The assay was validated against 2,2-diphenylpicrylhydrazyl (DPPH) assay, a known antioxidant assay.

  4. Accelerated glycerol fermentation in Escherichia coli using methanogenic formate consumption.

    PubMed

    Richter, Katrin; Gescher, Johannes

    2014-06-01

    Escherichia coli can ferment glycerol anaerobically only under very defined restrictive conditions. Hence, it was the aim of this study to overcome this limitation via a co-cultivation approach. Anaerobic glycerol fermentation by a pure E. coli culture was compared to a co-culture that also contained the formate-oxidizing methanogen Methanobacterium formicicum. Co-cultivation of the two strains led to a more than 11-fold increased glycerol consumption. Furthermore, it supported a constantly neutral pH and a shift from ethanol to succinate production. Moreover, M. formicicum was analyzed for its ability to grow on different standard media and a surprising versatility could be demonstrated.

  5. Bacterial self-defence: how Escherichia coli evades serum killing.

    PubMed

    Miajlovic, Helen; Smith, Stephen G

    2014-05-01

    The ability to survive the bactericidal action of serum is advantageous to extraintestinal pathogenic Escherichia coli that gain access to the bloodstream. Evasion of the innate defences present in serum, including complement and antimicrobial peptides, involves multiple factors. Serum resistance mechanisms utilized by E. coli include the production of protective extracellular polysaccharide capsules and expression of factors that inhibit or interfere with the complement cascade. Recent studies have also highlighted the importance of structural integrity of the cell envelope in serum survival. These survival strategies are outlined in this review with particular attention to novel findings and recent insights into well-established resistance mechanisms.

  6. Escherichia coli as a model active colloid: A practical introduction.

    PubMed

    Schwarz-Linek, Jana; Arlt, Jochen; Jepson, Alys; Dawson, Angela; Vissers, Teun; Miroli, Dario; Pilizota, Teuta; Martinez, Vincent A; Poon, Wilson C K

    2016-01-01

    The flagellated bacterium Escherichia coli is increasingly used experimentally as a self-propelled swimmer. To obtain meaningful, quantitative results that are comparable between different laboratories, reproducible protocols are needed to control, 'tune' and monitor the swimming behaviour of these motile cells. We critically review the knowledge needed to do so, explain methods for characterising the colloidal and motile properties of E. coli cells, and propose a protocol for keeping them swimming at constant speed at finite bulk concentrations. In the process of establishing this protocol, we use motility as a high-throughput probe of aspects of cellular physiology via the coupling between swimming speed and the proton motive force.

  7. Inducible repair of oxidative DNA damage in Escherichia coli.

    PubMed

    Demple, B; Halbrook, J

    Hydrogen peroxide is lethal to many cell types, including the bacterium Escherichia coli. Peroxides yield transient radical species that can damage DNA and cause mutations. Such partially reduced oxygen species are occasionally released during cellular respiration and are generated by lethal and mutagenic ionizing radiation. Because cells live in an environment where the threat of oxidative DNA damage is continual, cellular mechanisms may have evolved to avoid and repair this damage. Enzymes are known which evidently perform these functions. We report here that resistance to hydrogen peroxide toxicity can be induced in E. coli, that this novel induction is specific and occurs, in part, at the level of DNA repair.

  8. Sedimentation and gravitational instability of Escherichia coli Suspension

    NASA Astrophysics Data System (ADS)

    Douarche, Carine; Salin, Dominique; Collaboration between Laboratory FAST; LPS Collaboration

    2016-11-01

    The successive run and tumble of Escherichia coli bacteria provides an active matter suspension of rod-like particles with a large swimming diffusion. As opposed to inactive elongated particles, this diffusion prevents clustering and instability in the gravity field. We measure the time dependent E . coli concentration profile during their sedimentation. After some hours, due to the dioxygen consumption, a motile / non-motile front forms leading to a Rayleigh-Taylor type gravitational instability. Analyzing both sedimentation and instability in the framework of active particle suspensions, we can measure the relevant bacteria hydrodynamic characteristics such as its single particle sedimentation velocity and its hindrance volume.

  9. Susceptibility of Gnotobiotic Swine to Escherichia coli Isolated from Nonenteric Human Infections

    PubMed Central

    Meyer, R. C.; Rhoades, H. E.; Simon, J.

    1972-01-01

    Newborn, germfree piglets were susceptible to Escherichia coli associated with human, nonenteric infections and should provide a useful model in the study of generalized E. coli infections. PMID:4557565

  10. Flagella from F18+Escherichia coli play a role in adhesion to pig epithelial cell lines.

    PubMed

    Duan, Qiangde; Zhou, Mingxu; Zhu, Xiaofang; Yang, Yang; Zhu, Jun; Bao, Wenbin; Wu, Shenglong; Ruan, Xiaosai; Zhang, Weiping; Zhu, Guoqiang

    2013-02-01

    F18 fimbriae and toxins produced by F18 fimbriae-carrying Escherichia coli (E. coli) strains are known virulence factors responsible for post-weaning diarrhea (PWD) and edema disease (ED). In this study, we showed that fliC isogenic mutants constructed in two reference wild-type F18 fimbriae (F18+) E. coli were markedly impaired in adherence in vitro cell models (p < 0.05). Flagella purified from F18+E. coli could directly bind to cultured piglet epithelial cells and block adherence of F18+E. coli to cells when pre-incubated. In addition, the F18+E. coli fliC deletion mutants up-regulated the expression of type I fimbriae produced by F18+E. coli strains. These results demonstrated that expression of flagella is essential for the adherence of F18+E. coli in vitro.

  11. Virulence Factors and Stability of Coliphages Specific to Escherichia coli O157:H7 and to Various E. coli Infection.

    PubMed

    Kim, Eun-Jin; Chang, Hyun-Joo; Kwak, Soojin; Park, Jong-Hyun

    2016-12-28

    Characteristics of E. coli O157:H7-specific infection bacteriophages (O157 coliphages) and broad-host-range bacteriophages for other E. coli serotypes (broad-host coliphages) were compared. The burst sizes of the two groups ranged from 40 to 176 PFU/infected cell. Distributions of the virulence factors stx1, stx2, ehxA, and saa between the two groups were not differentiated. Broad-host-range coliphages showed lower stability at 70°C, in relation to O157 coliphages. However, O157 coliphages showed high acid and ethanol tolerance by reduction of only 22% and 11% phages, respectively, under pH 3 and 70% ethanol for 1 h exposure. Therefore, these results revealed that the O157 coliphages might be more stable under harsh environments, which might explain their effective infection of the acid-tolerant E. coli O157:H7.

  12. Escherichia coli Probiotic Strain ED1a in Pigs Has a Limited Impact on the Gut Carriage of Extended-Spectrum-β-Lactamase-Producing E. coli.

    PubMed

    Mourand, G; Paboeuf, F; Fleury, M A; Jouy, E; Bougeard, S; Denamur, E; Kempf, I

    2017-01-01

    Four trials were conducted to evaluate the impact of Escherichia coli probiotic strain ED1a administration to pigs on the gut carriage or survival in manure of extended-spectrum-β-lactamase-producing E. coli Groups of pigs were orally inoculated with strain E. coli M63 carrying the blaCTX-M-1 gene (n = 84) or used as a control (n = 26). In the first two trials, 24 of 40 E. coli M63-inoculated pigs were given E. coli ED1a orally for 6 days starting 8 days after oral inoculation. In the third trial, 10 E. coli M63-inoculated pigs were given either E. coli ED1a or probiotic E. coli Nissle 1917 for 5 days. In the fourth trial, E. coli ED1a was given to a sow and its 12 piglets, and these 12 piglets plus 12 piglets that had not received E. coli ED1a were then inoculated with E. coli M63. Fecal shedding of cefotaxime-resistant Enterobacteriaceae (CTX-RE) was studied by culture, and blaCTX-M-1 genes were quantified by PCR. The persistence of CTX-RE in manure samples from inoculated pigs or manure samples inoculated in vitro with E. coli M63 with or without probiotics was studied. The results showed that E. coli M63 and ED1a were good gut colonizers. The reduction in the level of fecal excretion of CTX-RE in E. coli ED1a-treated pigs compared to that in nontreated pigs was usually less than 1 log10 CFU and was mainly observed during the probiotic administration period. The results obtained with E. coli Nissle 1917 did not differ significantly from those obtained with E. coli ED1a. CTX-RE survival did not differ significantly in manure samples with or without probiotic treatment. In conclusion, under our experimental conditions, E. coli ED1a and E. coli Nissle 1917 could not durably prevent CTX-RE colonization of the pig gut.

  13. EcoR phylogenetic analysis and virulence genotyping of avian pathogenic Escherichia coli strains and Escherichia coli isolates from commercial chicken carcasses in southern Brazil.

    PubMed

    Kobayashi, Renata K T; Aquino, Ivani; Ferreira, Ana Lívia da S; Vidotto, Marilda C

    2011-05-01

    Escherichia coli strains designated as avian pathogenic E. coli (APEC) are responsible for avian colibacillosis, an acute and largely systemic disease that promotes significant economic losses in poultry industry worldwide because of mortality increase, medication costs, and condemnation of carcasses. APEC is a subgroup of extraintestinal pathogenic E. coli pathotype, which includes uropathogenic E. coli, neonatal meningitis E. coli, and septicemic E. coli. We isolated E. coli from commercial chicken carcasses in a Brazilian community and compared by polymerase chain reaction-defined phylogenetic group (A, B1, B2, or D) with APEC strains isolated from sick chickens from different poultry farms. A substantial number of strains assigned to phylogenetic E. coli reference collection group B2, which is known to harbor potent extraintestinal human and animal E. coli pathogens, were identified as APEC (26.0%) in both commercial chicken carcasses and retail poultry meat (retail poultry E. coli [RPEC]) (21.25%). The majority of RPEC were classified as group A (35%), whereas the majority of APEC were groups B1 (30.8) and A (27.6%). APEC and RPEC presented the genes pentaplex, iutA, hly, iron, ompT, and iss, but with different virulence profiles. The similarity between APEC and RPEC indicates RPEC as potentially pathogenic strains and supports a possible zoonotic risk for humans.

  14. Prevalence of genes encoding virulence factors among Escherichia coli with K1 antigen and non-K1 E. coli strains.

    PubMed

    Kaczmarek, Agnieszka; Budzynska, Anna; Gospodarek, Eugenia

    2012-10-01

    Multiplex PCR was used to detect genes encoding selected virulence determinants associated with strains of Escherichia coli with K1 antigen (K1(+)) and non-K1 E. coli (K1(-)). The prevalence of the fimA, fimH, sfa/foc, ibeA, iutA and hlyF genes was studied for 134 (67 K1(+) and 67 K1(-)) E. coli strains isolated from pregnant women and neonates. The fimA gene was present in 83.6 % of E. coli K1(+) and in 86.6 % of E. coli K1(-) strains. The fimH gene was present in all tested E. coli K1(+) strains and in 97.0 % of non-K1 strains. E. coli K1(+) strains were significantly more likely to possess the following genes than E. coli K1(-) strains: sfa/foc (37.3 vs 16.4 %, P = 0.006), ibeA (35.8 vs 4.5 %, P<0.001), iutA (82.1 vs 35.8 %, P<0.001) and hlyF (28.4 vs 6.0 %, P<0.001). In conclusion, E. coli K1(+) seems to be more virulent than E. coli K1(-) strains in developing severe infections, thereby increasing possible sepsis or neonatal bacterial meningitis.

  15. The udhA Gene of Escherichia coli Encodes a Soluble Pyridine Nucleotide Transhydrogenase

    PubMed Central

    Boonstra, Birgitte; French, Christopher E.; Wainwright, Ian; Bruce, Neil C.

    1999-01-01

    The udhA gene of Escherichia coli was cloned and expressed in E. coli and found to encode an enzyme with soluble pyridine nucleotide transhydrogenase activity. The N-terminal end of the enzyme contains the fingerprint motif of a dinucleotide binding domain, not present in published E. coli genome sequences due to a sequencing error. E. coli is hereby the first organism reported to possess both a soluble and a membrane-bound pyridine nucleotide transhydrogenase. PMID:9922271

  16. CARDIORESPIRATORY AND METABOLIC RESPONSES TO LIVE E. COLI AND ENDOTOXIN IN THE MONKEY

    DTIC Science & Technology

    of live organisms (Escherichia coli) were compared with endotoxin and saline in rhesus monkeys. Six animals were given E . coli , six endotoxin, and...five served as controls. Studies were conducted for 2-4 hours. The mean cardiac output decreased 62% within 60-90 minutes in the E . coli group and 41...Pco2 decreased to 24 mm Hg in the E . coli group and 26 mm Hg in the endotoxin group. Arterial hypoxemia developed in four animals and high

  17. Escherichia coli O104:H4 Pathogenesis: an Enteroaggregative E. coli/Shiga Toxin-Producing E. coli Explosive Cocktail of High Virulence.

    PubMed

    Navarro-Garcia, Fernando

    2014-12-01

    A major outbreak caused by Escherichia coli of serotype O104:H4 spread throughout Europe in 2011. This large outbreak was caused by an unusual strain that is most similar to enteroaggregative E. coli (EAEC) of serotype O104:H4. A significant difference, however, is the presence of a prophage encoding the Shiga toxin, which is characteristic of enterohemorrhagic E. coli (EHEC) strains. This combination of genomic features, associating characteristics from both EAEC and EHEC, represents a new pathotype. The 2011 E. coli O104:H4 outbreak of hemorrhagic diarrhea in Germany is an example of the explosive cocktail of high virulence and resistance that can emerge in this species. A total of 46 deaths, 782 cases of hemolytic-uremic syndrome, and 3,128 cases of acute gastroenteritis were attributed to this new clone of EAEC/EHEC. In addition, recent identification in France of similar O104:H4 clones exhibiting the same virulence factors suggests that the EHEC O104:H4 pathogen has become endemically established in Europe after the end of the outbreak. EAEC strains of serotype O104:H4 contain a large set of virulence-associated genes regulated by the AggR transcription factor. They include, among other factors, the pAA plasmid genes encoding the aggregative adherence fimbriae, which anchor the bacterium to the intestinal mucosa (stacked-brick adherence pattern on epithelial cells). Furthermore, sequencing studies showed that horizontal genetic exchange allowed for the emergence of the highly virulent Shiga toxin-producing EAEC O104:H4 strain that caused the German outbreak. This article discusses the role these virulence factors could have in EAEC/EHEC O104:H4 pathogenesis.

  18. Colonization with extraintestinal pathogenic Escherichia coli among nursing home residents and its relationship to fluoroquinolone resistance.

    PubMed

    Maslow, Joel N; Lautenbach, Ebbing; Glaze, Thomas; Bilker, Warren; Johnson, James R

    2004-09-01

    In a cross-sectional fecal prevalence survey involving 49 residents of a Veterans Affairs nursing home, 59% of subjects were colonized with extraintestinal pathogenic Escherichia coli (ExPEC), 22% were colonized with adhesin-positive E. coli, and 51% were colonized with fluoroquinolone-resistant E. coli. Among 80 unique isolates, adhesins correlated negatively and aerobactin correlated positively with fluoroquinolone resistance.

  19. Editorial: Emerging approaches for typing, detection, characterization, and traceback of Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commensal E. coli inhabit the large intestines of humans and animals and are important in maintaining normal intestinal homeostasis. There are also many groups of disease-causing E. coli, including diarrheagenic and extra-intestinal pathogenic E. coli (ExPEC). There are approximately O188 somatic O...

  20. A glimpse of Escherichia coli O157:H7 survival in soils from eastern China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli O157:H7 (E. coli O157:H7) is an important food-borne pathogen, which continues to be a major public health concern worldwide. It is known that E. coli O157:H7 survive in soil environment might result in the contamination of fresh produce or water source. To investigate how the soils...

  1. Escherichia coli strain diversity: Selecting isolates for use as pathogen surrogates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background Escherichia coli (E. coli) is commonly used as a surrogate for pathogens in research to identify sources of agricultural contamination and to characterize how pathogens persist on plant surfaces. However, E. coli strains are highly diverse, exhibiting differences in physical, chemical and...

  2. Mouse in vivo neutralization of Escherichia coli Shiga toxin 2 with monoclonal antibodies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli (E. coli) food contaminations pose serious health and food safety concerns, and have been the subject of massive food recalls. Shiga toxin 2 (Stx2)-producing E. coli has been identified as the major cause of hemorrhagic colitis and hemolytic uremic syndrome (HUS), the most severe di...

  3. Detection of Escherichia Coli O157:H7 in Fecal Samples in Meat Goats

    ERIC Educational Resources Information Center

    Mobley, Ray; Madden, Uford; Brooks-Walter, Alexis

    2004-01-01

    Studies have reported the isolation of Escherichia coli (E. coli)O157:H7 from pork, lamb and poultry products, and from other animals including deer, horses, dogs, birds and humans. There is limited or no information on the presence of the organism in goats. The objectives of this study were to determine if E. coli O157:H7 was naturally occurring…

  4. Resistance of various shiga toxin-producing Escherichia coli to electrolyzed oxidizing water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The resistance of thirty two strains of Escherichia coli O157:H7 and six major serotypes of non-O157 Shiga toxin- producing E. coli (STEC) plus E. coli O104 was tested against Electrolyzed oxidizing (EO) water using two different methods; modified AOAC 955.16 sequential inoculation method and minim...

  5. Ubiquity and Persistence of Escherichia coli in a Midwestern Coastal Stream†

    PubMed Central

    Byappanahalli, Muruleedhara; Fowler, Melanie; Shively, Dawn; Whitman, Richard

    2003-01-01

    Dunes Creek, a small Lake Michigan coastal stream that drains sandy aquifers and wetlands of Indiana Dunes, has chronically elevated Escherichia coli levels along the bathing beach near its outfall. This study sought to understand the sources of E. coli in Dunes Creek's central branch. A systematic survey of random and fixed sampling points of water and sediment was conducted over 3 years. E. coli concentrations in Dunes Creek and beach water were significantly correlated. Weekly monitoring at 14 stations during 1999 and 2000 indicated chronic loading of E. coli throughout the stream. Significant correlations between E. coli numbers in stream water and stream sediment, submerged sediment and margin, and margin and 1 m from shore were found. Median E. coli counts were highest in stream sediments, followed by bank sediments, sediments along spring margins, stream water, and isolated pools; in forest soils, E. coli counts were more variable and relatively lower. Sediment moisture was significantly correlated with E. coli counts. Direct fecal input inadequately explains the widespread and consistent occurrence of E. coli in the Dunes Creek watershed; long-term survival or multiplication or both seem likely. The authors conclude that (i) E. coli is ubiquitous and persistent throughout the Dunes Creek basin, (ii) E. coli occurrence and distribution in riparian sediments help account for the continuous loading of the bacteria in Dunes Creek, and (iii) ditching of the stream, increased drainage, and subsequent loss of wetlands may account for the chronically high E. coli levels observed. PMID:12902241

  6. Mechanisms of antibiotic resistance to enrofloxacin in uropathogenic Escherichia coli in dog

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli (E. coli) urinary tract infections (UTIs) are becoming a serious problem both for pets and humans (zoonosis) due to the close contact and to the increasing resistance to antibiotics. Canine E. coli represents a good experimental model useful to study this pathology. Moreover, as des...

  7. 76 FR 72331 - Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... Toxin-Producing Escherichia coli in Certain Raw Beef Products AGENCY: Food Safety and Inspection Service... methods for controlling non-O157 Shiga toxin-producing Escherichia coli in raw, intact and non-intact beef... Escherichia coli in raw, intact and non-intact beef products and product components on or before December...

  8. A homolog of an Escherichia coli phosphate-binding protein gene from Xanthomonas oryzae pv. oryzae

    NASA Technical Reports Server (NTRS)

    Hopkins, C. M.; White, F. F.; Heaton, L. A.; Guikema, J. A.; Leach, J. E.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    A Xanthomonas oryzae pv. oryzae gene with sequence similarity to an Escherichia coli phosphate-binding protein gene (phoS) produces a periplasmic protein of apparent M(r) 35,000 when expressed in E. coli. Amino terminal sequencing revealed that a signal peptide is removed during transport to the periplasm in E. coli.

  9. Comparison of whole genome sequences from human and non-human Escherichia coli O26 strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shiga toxin-producing Escherichia coli (STEC) O26 is the second leading E. coli serogroup responsible for human illness outbreaks behind E. coli O157:H7. Recent outbreaks have been linked to emerging pathogenic O26:H11 strains harboring stx2 only. Cattle have been recognized as an important reserv...

  10. SURVIVAL OF ESCHERICHIA COLI 0157:H7 IN DAIRY CATTLE FEED WATER

    EPA Science Inventory

    Cattle feed waters from two dairy farms were used in a study to determine the survival characteristics of the bacterial pathogen Escherichia coli )157:H7 and wild-type E. coli. The E. coli 0157:H7 inoculum consisted of a consortium of isolates obtained from dairy cattle. Fresh ma...

  11. Proteomic differences between Escherichia coli strains that cause transient versus persistent intramammary infections [abstract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli is a leading cause of bacterial mastitis in dairy cattle. Typically this infection is transient in nature and lasts 2-3 days. However, in a minority of cases, E. coli can cause a persistent intramammary infection. The mechanisms that enable certain strains of E. coli to cause a p...

  12. Enterotoxigenic Escherichia coli and Vibrio cholerae diarrhea, Bangladesh, 2004.

    PubMed

    Qadri, Firdausi; Khan, Ashraful I; Faruque, Abu Syed G; Begum, Yasmin Ara; Chowdhury, Fahima; Nair, Gopinath B; Salam, Mohammed A; Sack, David A; Svennerholm, Ann-Mari

    2005-07-01

    Flooding in Dhaka in July 2004 caused epidemics of diarrhea. Enterotoxigenic Escherichia coli (ETEC) was almost as prevalent as Vibrio cholerae O1 in diarrheal stools. ETEC that produced heat-stable enterotoxin alone was most prevalent, and 78% of strains had colonization factors. Like V. cholerae O1, ETEC can cause epidemic diarrhea.

  13. Genomic analysis of extra-intestinal pathogenic Escherichia coli urosepsis.

    PubMed

    McNally, A; Alhashash, F; Collins, M; Alqasim, A; Paszckiewicz, K; Weston, V; Diggle, M

    2013-08-01

    Urosepsis is a bacteraemia infection caused by an organism previously causing an infection in the urinary tract of a patient, a diagnosis which has been classically confirmed by culture of the same species of bacteria from both blood and urine samples. Given the new insights afforded by sequencing technologies into the complicated population structures of infectious agents affecting humans, we sought to investigate urosepsis by comparing the genome sequences of blood and urine isolates of Escherichia coli from five patients with urosepsis. The results confirm the classical urosepsis hypothesis in four of the five cases, but also show the complex nature of extra-intestinal E. coli infection in the fifth case, where three distinct strains caused two distinct infections. Additionally, we show there is little to no variation in the bacterial genome as it progressed from urine to blood, and also present a minimal set of virulence genes required for bacteraemia in E. coli based on gene association. These suggest that most E. coli have the genetic propensity to cause bacteraemia.

  14. Genetic Attributes of E. coli Isolates from Chlorinated Drinking Water

    PubMed Central

    Blyton, Michaela D. J.; Gordon, David M.

    2017-01-01

    Escherichia coli, is intimately associated with both human health and water sanitation. E. coli isolates from water can either be (i) host associated commensals, indicating recent faecal contamination; (ii) diarrheal pathogens or (iii) extra-intestinal pathogens that pose a direct health risk; or (iv) free-living. In this study we genetically characterised 28 E. coli isolates obtained from treated drinking water in south eastern Australia to ascertain their likely source. We used full genome sequencing to assign the isolates to their phylogenetic group and multi-locus sequence type. The isolates were also screened in silico for several virulence genes and genes involved in acquired antibiotic resistance. The genetic characteristics of the isolates indicated that four isolates were likely human pathogens. However, these isolates were not detected in sufficient numbers to present a health risk to the public. An additional isolate was a human associated strain. Nine isolates were water associated free-living strains that were unlikely to pose a health risk. Only 14% of the isolates belonged to the host associated phylogenetic group (B2) and only a single isolate had any antibiotic resistance genes. This suggests that the primary source of the drinking water E. coli isolates may not have been recent human faecal contamination. PMID:28107364

  15. Characterization of a second lysine decarboxylase isolated from Escherichia coli.

    PubMed Central

    Kikuchi, Y; Kojima, H; Tanaka, T; Takatsuka, Y; Kamio, Y

    1997-01-01

    We report here on the existence of a new gene for lysine decarboxylase in Escherichia coli K-12. The hybridization experiments with a cadA probe at low stringency showed that the homologous region of cadA was located in lambda Kohara phage clone 6F5 at 4.7 min on the E. coli chromosome. We cloned the 5.0-kb HindIII fragment of this phage clone and sequenced the homologous region of cadA. This region contained a 2,139-nucleotide open reading frame encoding a 713-amino-acid protein with a calculated molecular weight of 80,589. Overexpression of the protein and determination of its N-terminal amino acid sequence defined the translational start site of this gene. The deduced amino acid sequence showed 69.4% identity to that of lysine decarboxylase encoded by cadA at 93.7 min on the E. coli chromosome. In addition, the level of lysine decarboxylase activity increased in strains carrying multiple copies of the gene. Therefore, the gene encoding this lysine decarboxylase was designated Idc. Analysis of the lysine decarboxylase activity of strains containing cadA, ldc, or cadA ldc mutations indicated that ldc was weakly expressed under various conditions but is a functional gene in E. coli. PMID:9226257

  16. armA and aminoglycoside resistance in Escherichia coli.

    PubMed

    González-Zorn, Bruno; Teshager, Tirushet; Casas, María; Porrero, María C; Moreno, Miguel A; Courvalin, Patrice; Domínguez, Lucas

    2005-06-01

    We report armA in an Escherichia coli pig isolate from Spain. The resistance gene was borne by self-transferable IncN plasmid pMUR050. Molecular analysis of the plasmid and of the armA locus confirmed the spread of this resistance determinant.

  17. armA and Aminoglycoside Resistance in Escherichia coli

    PubMed Central

    González-Zorn, Bruno; Teshager, Tirushet; Casas, María; Porrero, María C.; Courvalin, Patrice; Domínguez, Lucas

    2005-01-01

    We report armA in an Escherichia coli pig isolate from Spain. The resistance gene was borne by self-transferable IncN plasmid pMUR050. Molecular analysis of the plasmid and of the armA locus confirmed the spread of this resistance determinant. PMID:15963296

  18. Escherichia coli as other Enterobacteriaceae: food poisoning and health effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many Escherichia coli strains are harmless, and they are an important commensal in the intestinal microflora; however, pathogenic strains also exist. The pathogenic strains can be divided into diarrhea-inducing strains and strains that reside in the intestines but only cause disease in bodily sites...

  19. A second DNA methyltransferase repair enzyme in Escherichia coli.

    PubMed Central

    Rebeck, G W; Coons, S; Carroll, P; Samson, L

    1988-01-01

    The Escherichia coli ada-alkB operon encodes a 39-kDa protein (Ada) that is a DNA-repair methyltransferase and a 27-kDa protein (AlkB) of unknown function. By DNA blot hybridization analysis we show that the alkylation-sensitive E. coli mutant BS23 [Sedgwick, B. & Lindahl, T. (1982) J. Mol. Biol. 154, 169-175] is a deletion mutant lacking the entire ada-alkB operon. Despite the absence of the ada gene and its product, the cells contain detectable levels of a DNA-repair methyltransferase activity. We conclude that the methyltransferase in BS23 cells is the product of a gene other than ada. A similar activity was detected in extracts of an ada-10::Tn10 insertion mutant of E. coli AB1157. This DNA methyltransferase has a molecular mass of about 19 kDa and transfers the methyl groups from O6-methylguanine and O4-methylthymine in DNA, but not those from methyl phosphotriester lesions. This enzyme was not induced by low doses of alkylating agent and is expressed at low levels in ada+ and a number of ada- E. coli strains. Images PMID:3283737

  20. Characterization of Campylobacter jejuni and coli strains isolated in turkeys

    Technology Transfer Automated Retrieval System (TEKTRAN)

    associated with significant foodborne disease. Campylobacter jejuni and C. coli are the two most prevalent species contributing to human diarrheal disease. The objective of this study was to determine the routes of transmission for Campylobacter throughout turkey production and processing. A floc...

  1. Escherichia coli growth studied by dual-parameter flow cytophotometry.

    PubMed Central

    Steen, H B; Boye, E

    1981-01-01

    The growth of Escherichia coli cells has been analyzed for the first time by dual-parameter flow cytophotometry, in which the deoxyribonucleic acid and protein contents of single bacteria have been measured simultaneously with an accuracy of a few percent and at a rate of 3,000 cells/s. PMID:7007339

  2. Compilation of DNA sequences of Escherichia coli (update 1992)

    PubMed Central

    Kröger, Manfred; Wahl, Ralf; Schachtel, Gabriel; Rice, Peter

    1992-01-01

    We have compiled the DNA sequence data for E.coli available from the GENBANK and EMBL data libraries and over a period of several years independently from the literature. This is the fourth listing replacing and increasing the former listings substantially. However, in order to save space this printed version contains DNA sequence information only, if they are publically available in electronic form. The complete compilation including a full set of genetic map data and the E.coli protein index can be obtained in machine readable form from the EMBL data library (ECD release 10) or from the CD-ROM version of this supplement issue directly. After deletion of all detected overlaps a total of 1 820 237 individual bp is found to be determined till the beginning of 1992. This corresponds to a total of 38.56% of the entire E.coli chromosome consisting of about 4,720 kbp. This number may actually be higher by some extra 2,5% derived from lysogenic bacteriophage lambda and various DNA sequences already received for other strains of E.coli. PMID:1598239

  3. Compilation of DNA sequences of Escherichia coli (update 1993).

    PubMed Central

    Kröger, M; Wahl, R; Rice, P

    1993-01-01

    We have compiled the DNA sequence data for E. coli available from the GENBANK and EMBL data libraries and over a period of several years independently from the literature. This is the fifth listing replacing and increasing the former listings substantially. However, in order to save space this printed version contains DNA sequence information only, if they are publically available in electronic form. The complete compilation including a full set of genetic map data and the E. coli protein index can be obtained in machine readable form from the EMBL data library (ECD release 15) as a part of the CD-ROM issue of the EMBL sequence database, released and updated every three months. After deletion of all detected overlaps a total of 2,353,635 individual bp is found to be determined till the end of April 1993. This corresponds to a total of 49.87% of the entire E. coli chromosome consisting of about 4,720 kbp. This number may actually be higher by 9161 bp derived from other strains of E. coli. PMID:8332520

  4. Progressive genome-wide introgression in agricultural Campylobacter coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hybridization between distantly related organisms can facilitate rapid adaptation but is constrained by epistatic fitness interactions. The zoonotic pathogens Campylobacter coli and C. jejuni differ from each other at an average of nearly 40 amino acids per gene. Nevertheless, they have started to e...

  5. More than a locomotive organelle: flagella in Escherichia coli.

    PubMed

    Zhou, Mingxu; Yang, Yang; Chen, Panlin; Hu, Huijie; Hardwidge, Philip R; Zhu, Guoqiang

    2015-11-01

    The flagellum is a locomotive organelle that allows bacteria to respond to chemical gradients. This review summarizes the current knowledge regarding Escherichia coli flagellin variants and the role of flagella in bacterial functions other than motility, including the relationship between flagella and bacterial virulence.

  6. Genome Sequence of Enterotoxigenic Escherichia coli Strain FMU073332.

    PubMed

    Saldaña-Ahuactzi, Zeus; Cruz-Córdova, Ariadnna; Rodea, Gerardo E; Porta, Helena; Navarro-Ocaña, Armando; Eslava-Campos, Carlos; Cevallos, Miguel A; Xicohtencatl-Cortes, Juan

    2017-02-23

    Enterotoxigenic Escherichia coli (ETEC) is an important cause of bacterial diarrheal illness, affecting practically every population worldwide, and was estimated to cause 120,800 deaths in 2010. Here, we report the genome sequence of ETEC strain FMU073332, isolated from a 25-month-old girl from Tlaltizapán, Morelos, México.

  7. Stringent control of FLP recombinase in Escherichia coli.

    PubMed

    Bowden, Steven D; Palani, Nagendra P; Libourel, Igor G L

    2017-02-01

    Site specific recombinases are invaluable tools in molecular biology, and are emerging as powerful recorders of cellular events in synthetic biology. We have developed a stringently controlled FLP recombinase system in Escherichia coli using an arabinose inducible promoter combined with a weak ribosome binding site.

  8. Wastewater as a Source of Carbapenem Resistant Escherichia coli

    EPA Science Inventory

    Clinical studies have reported that the occurrence of carbapenem resistant E. coli is on the rise. This is of concern because carbapenem antibiotics are typically reserved for treating infections caused by bacteria resistant to other classes of antibiotics. Current literature st...

  9. Enteroinvasive Escherichia coli severe dysentery complicated by rotavirus gastroenteritis.

    PubMed

    Pacheco-Gil, Leova; Ochoa, Theresa J; Flores-Romo, Leopoldo; DuPont, Herbert L; Estrada-Garcia, Teresa

    2006-11-01

    Enteroinvasive Escherichia coli (EIEC) is an important agent of pediatric diarrhea and dysentery in developing countries. We report a life-threatening severe dysentery case due to EIEC in a malnourished 4-month-old male, native Indian infant co-infected with rotavirus. The severe gastrointestinal bleeding anemia and hypovolemic shock was successfully treated with IV blood transfusions, rehydration and antibiotic therapy.

  10. Redefining the requisite lipopolysaccharide structure in Escherichia coli.

    PubMed

    Meredith, Timothy C; Aggarwal, Parag; Mamat, Uwe; Lindner, Buko; Woodard, Ronald W

    2006-02-17

    Gram-negative bacteria possess an asymmetric lipid bilayer surrounding the cell wall, the outer membrane (OM). The OM inner leaflet is primarily composed of various glycerophospholipids, whereas the outer leaflet predominantly contains the unique amphiphilic macromolecule, lipopolysaccharide (LPS or endotoxin). The majority of all gram-negative bacteria elaborate LPS containing at least one 2-keto 3-deoxy-D-manno-octulosonate (Kdo) molecule. The minimal LPS structure required for growth of Escherichia coli has long been recognized as two Kdo residues attached to lipid A, inextricably linking viability to toxicity. Here we report the construction and characterization of the nonconditional E. coli K-12 suppressor strain KPM22 that lacks Kdo and is viable despite predominantly elaborating the endotoxically inactive LPS precursor lipid IV(A). Our results challenge the established E. coli Kdo2-lipid A dogma, indicating that the previously observed and well-documented dependence of cell viability on the synthesis of Kdo stems from a lethal pleiotropy precipitated after the depletion of the carbohydrate, rather than an inherent need for the Kdo molecule itself as an indispensable structural component of the OM LPS layer. Inclusion of the inner membrane LPS transporter MsbA on a multicopy plasmid partially suppresses the lethal deltaKdo phenotype directly in the auxotrophic parent strain, suggesting increased rates of nonglycosylated lipid A transport can, in part, compensate for Kdo depletion. The unprecedented nature of a lipid IV(A) OM redefines the requisite LPS structure for viability in E. coli.

  11. Survival of Escherichia coli and Enterococcus in Stream Water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    E. coli and Enterococcus indicate fecal contamination and are used for monitoring of lakes, streams, and rivers. Transport of bacteria from manured or pastured lands can result in large bacterial loads from both small and large runoff events and the persistence of bacteria following these loadings i...

  12. The alternative methods for disinfection of E. coli

    NASA Astrophysics Data System (ADS)

    Yetim, Tuba; Görmez, Arzu; Gürkök, Sümeyra

    2016-04-01

    Recently, advanced oxidation processes have gained significant interest for bacterial inactivation. In the present study, the efficacy of sonolysis, photocatalysis and sonophotocatalysis was evaluated for disinfection of Escherichia coli O157:H7 strain. Sonophotocatalysis proved to be the most effective disinfection methods by generating greater amount of •OHradical.

  13. A Novel Physical Technique for E. Coli Removal from Stormwater

    EPA Science Inventory

    In addition to heavy metals and polymeric aromatic hydrocarbons(PAHs), pathogens such as E.Coli contribute to the overall pollutant load in urban stormwater runoff. A number of constructed landscape features, collectively known as structural best management practices (BMPs) are e...

  14. Resistance patterns of Escherichia coli causing urinary tract infection

    PubMed Central

    Ferdosi-Shahandashti, Elaheh; Javanian, Mostafa; Moradian-Kouchaksaraei, Masoomeh; Yeganeh, Babak; Bijani, Ali; Motevaseli, Elahe; Moradian- Kouchaksaraei, Fatemeh

    2015-01-01

    Background: Urinary tract infection (UTI) is one of the most prevalent infectious diseases and Escherichia coli is its common cause. The aim of this study was to assess the resistance patterns of E.coli in urinary tract infections and to determine the susceptibility of E.coli to commonly used antimicrobials and also to evaluate the options for empirical treatment of UTI. Methods: This study was conducted in the Ayatollah Rouhani Teaching Hospital of Babol Medical Sciences University in North of Iran. Between January of 2013 to December 2013, antimicrobial susceptibility tests were done by disk diffusion and microdilution method. Growth of >=105 cfu/ml was considered as positive urine test. Ten commonly used antibiotics were examined for susceptibility test. Data and the results were collected and analyzed. Results: E.coli grew in 57 urine samples. Imipenem, ofloxacin, ciprofloxacin were the most sensitive antibiotics at 87.7%, 87.7% and 78.9% respectively. Whereas, cotrimoxazole, cefexime, cefotaxcime and ceftriaxone were the most resistant antibiotics. Antibiotic sensitivity of disk diffusion compared minimum inhibitory concentration (MIC) detected by microdilution had the sensitivity, specificity, positive predictive value and negative predictive value of 82%, 98%, 99% and 74%, respectively. Conclusion: Imipenem, ofloxacin and ciprofloxacin should be used in empirical therapy of UTI. PMID:26644881

  15. TRIMETHOPRIM-SULFAMETHOXAZOLE RESISTANCE IN SEWAGE ISOLATES OF ESCHERICHIA COLI

    EPA Science Inventory

    The increase in resistance rates to trimehtoprim-sulfamethoxazole (TMP/SMX) in isolates of Escherichia coli has become a matter of increasing concern. This has been particularly true in reference to community acquired urinary tract infections (UTI). This study utilized sewage i...

  16. Escherichia coli and other Enterobacteriaceae: Food poisoning and health effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The family Enterobactericeae consists of rod-shaped, Gram-negative, facultatively anaerobic, non-spore forming bacteria and also includes the food-borne pathogens, Cronobacter spp., Escherichia coli, Salmonella enterica, Shigella spp., and Yersinia spp. Illness caused by these pathogens is acquired...

  17. Genome Sequence of Enterotoxigenic Escherichia coli Strain FMU073332

    PubMed Central

    Saldaña-Ahuactzi, Zeus; Cruz-Córdova, Ariadnna; Rodea, Gerardo E.; Porta, Helena; Navarro-Ocaña, Armando; Eslava-Campos, Carlos

    2017-01-01

    ABSTRACT   Enterotoxigenic Escherichia coli (ETEC) is an important cause of bacterial diarrheal illness, affecting practically every population worldwide, and was estimated to cause 120,800 deaths in 2010. Here, we report the genome sequence of ETEC strain FMU073332, isolated from a 25-month-old girl from Tlaltizapán, Morelos, México. PMID:28232434

  18. UV inactivation of E. coli in liquid egg white

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An ultraviolet light (UV) system was developed to pasteurize liquid egg white. The system consisted of low-pressure mercury bulbs surrounded by UV transparent tubing. Egg white was inoculated with Escherichia coli K12 and pumped through the UV system at a flow rate of 330 ml/min. The effects of trea...

  19. New types of Escherichia coli recombination-deficient mutants.

    PubMed

    Freifelder, D

    1976-11-01

    A set of Escherichia coli mutants deficient in intramolecular recombination and different from those previously found is described. All have temperature-sensitive lethal mutations. The mutants have been characterized with respect to the following properties: the Pap phenotype, deoxyribonucleic acid synthesis, sensitivity to ultraviolet light, ability to support the growth of phage lambda, filament formation, and mutation frequency.

  20. New types of Escherichia coli recombination-deficient mutants.

    PubMed Central

    Freifelder, D

    1976-01-01

    A set of Escherichia coli mutants deficient in intramolecular recombination and different from those previously found is described. All have temperature-sensitive lethal mutations. The mutants have been characterized with respect to the following properties: the Pap phenotype, deoxyribonucleic acid synthesis, sensitivity to ultraviolet light, ability to support the growth of phage lambda, filament formation, and mutation frequency. PMID:789362