Photoreactivating enzyme from Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Snapka, R M; Fuselier, C O [California Univ., Irvine (USA)

1977-05-01

Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm.

Complete Genome Sequence of Escherichia coli Strain WG5

DEFF Research Database (Denmark)

Imamovic, Lejla; Misiakou, Maria-Anna; van der Helm, Eric

2018-01-01

Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain.......Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain....

99mTechnetium labelled Escherichia coli

International Nuclear Information System (INIS)

Diniz, S.O.F.; Cardoso, V.N.; Resende, B.M.; Nunan, E.A.; Simal, C.J.R.

1999-01-01

Samples of a culture of unlabeled Escherichia coli were incubated with different concentrations of stannous chloride for various time periods. 99m Tc (26.0 MBq) was added to each preparation and the results showed a labelling yield of 98% for E. coli. Since the bacterial viability of 99m Tc-E. coli and E. coli did not show any statistical differences, these results demonstrate that labelling of E. coli with 99m Tc does not modify the bacterial viability, and the radiolabelled bacteria may be a good model to study bacterial translocation

An engineered non-oxidative glycolysis pathway for acetone production in Escherichia coli.

Science.gov (United States)

Yang, Xiaoyan; Yuan, Qianqian; Zheng, Yangyang; Ma, Hongwu; Chen, Tao; Zhao, Xueming

2016-08-01

To find new metabolic engineering strategies to improve the yield of acetone in Escherichia coli. Results of flux balance analysis from a modified Escherichia coli genome-scale metabolic network suggested that the introduction of a non-oxidative glycolysis (NOG) pathway would improve the theoretical acetone yield from 1 to 1.5 mol acetone/mol glucose. By inserting the fxpk gene encoding phosphoketolase from Bifidobacterium adolescentis into the genome, we constructed a NOG pathway in E.coli. The resulting strain produced 47 mM acetone from glucose under aerobic conditions in shake-flasks. The yield of acetone was improved from 0.38 to 0.47 mol acetone/mol glucose which is a significant over the parent strain. Guided by computational analysis of metabolic networks, we introduced a NOG pathway into E. coli and increased the yield of acetone, which demonstrates the importance of modeling analysis for the novel metabolic engineering strategies.

Genetic analysis of an Escherichia coli urease locus: evidence of DNA rearrangement.

OpenAIRE

Collins, C M; Falkow, S

1988-01-01

Ureolytic Escherichia coli strains are uncommon clinical isolates. The urease phenotype in a large percentage of these isolates is unstable and lost upon storage. We examined two urease-positive uropathogenic E. coli isolates that give off urease-negative segregants and determined that the urease phenotype was chromosomally encoded. The urease phenotype was cloned from E. coli 1021 and found to be encoded on a 9.4-kilobase HindIII restriction fragment. Transposon mutagenesis indicated that at...

Phylogenetic analysis of Escherichia coli isolates from healthy and diarrhoeic calves in Mashhad, Iran

Directory of Open Access Journals (Sweden)

M. Barzan

2017-03-01

Full Text Available Escherichia coli is a normal inhabitant of the gastrointestinal tract of vertebrates. Certain Escherichia coli strains have been associated with neonatal diarrhoea in ruminants. These strains can be assigned to one of the four main phylogenetic groups, A, B1, B2 and D. Several studies have shown the rela-tionship between phylogeny and pathogenicity of E. coli, a great deal can be obtained by determining the phylogroup of unknown E. coli strains. In this study, we aimed to evaluate the influence of diar-rhoea on the genetic composition of E. coli populations isolated from calves. A total of 80 Es-cherichia coli isolates were obtained from healthy and diarrhoeic calves. Phylogenetic grouping was done based on the Clermont triplex PCR method using primers targeted at three genetic markers, chuA, yjaA and TspE4.C2. According to our results, phylogenetic group A strains was the most prevalent in both healthy (37.5% and diarrhoeic calves (55%. Group B1 contained 27.5% of isolates in healthy calves, followed by group B2 (17.5%, and group D (7.5%. Also, four isolates from healthy calves were not included in the major phylogenetic groups or subgroups. A total of 14% and 4% of isolates from diarrhoeic calves beloned to phylogroups B2 and D respectively. Although no isolate from diarrhoeic calves was found to belong to group B1, there was no significant difference between healthy and diarrhoeic calves for other phylogroups. There was not a dramatic shift in E. coli phylogroup/subgroup due to occurrence of diarrhoea in calves, except for phylogroup B1 which was higher in healthy calves. This can be due to the difference in secretions of digestive system in diarrhoeic calves which can prevent the conditions for instability of Escherichia coli isolates of phy-logroup B1. The majority of isolates from both healthy and diarrhoeic calves belonged to non-pathogenic phylogentic group A and B1.

Asymptomatic bacteriuria Escherichia coli strains

DEFF Research Database (Denmark)

Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

2006-01-01

Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast...... to uropathogenic E. coli (UPEC) that cause symptomatic UTI, very little is known about the mechanisms by which these strains colonize the urinary tract. Here, we have investigated the growth characteristics in human urine as well as adhesin repertoire of nine ABU strains; the ability of ABU strains to compete...

Genetic and molecular analyses of Escherichia coli N-acetylneuraminate lyase gene.

OpenAIRE

Kawakami, B; Kudo, T; Narahashi, Y; Horikoshi, K

1986-01-01

Two plasmids containing the N-acetylneuraminate lyase (NALase) gene (nanA) of Escherichia coli, pNL1 and pNL4, were constructed. Immunoprecipitation analysis indicated that the 35,000-dalton protein encoded in pNL4 was NALase. The synthesis of NALase in E. coli carrying these plasmids was constitutive.

Analysis of early-onset bloodstream infection due to Escherichia coli infection in premature babies

OpenAIRE

Chen, I-Lun; Huang, Hsin-Chun; Wu, Chih-Te; Ou-Yang, Mei-Chen; Chung, Mei-Yung; Chen, Chih-Cheng; Suen, Jau-Ling; Hung, Chih-Hsing

2017-01-01

Abstract In early-onset bacteremia among preterm neonates, Escherichia coli (E. coli) is the main pathogen and can cause a high mortality rate. Thus, the predictive factors of mortality and extended-spectrum ?-lactamase (ESBL)-producing E. coli in preterm babies with E. coli early-onset bacteremia were reported. We retrospectively reviewed preterm neonates who had E. coli bacteremia occurring within 3 days after birth between 2004 and 2015. Maternal and perinatal information were collected fr...

Colonization of Enteroaggregative Escherichia coli and Shiga toxin-producing Escherichia coli in chickens and humans in southern Vietnam

NARCIS (Netherlands)

Trung, Nguyen Vinh; Nhung, Hoang Ngoc; Carrique-Mas, Juan J.; Mai, Ho Huynh; Tuyen, Ha Thanh; Campbell, James; Nhung, Nguyen Thi; van Minh, Pham; Wagenaar, Jaap A.; Mai, Nguyen Thi Nhu; Hieu, Thai Quoc; Schultsz, Constance; Hoa, Ngo Thi

2016-01-01

Enteroaggregative (EAEC) and Shiga-toxin producing Escherichia coli (STEC) are a major cause of diarrhea worldwide. E. coli carrying both virulence factors characteristic for EAEC and STEC and producing extended-spectrum beta-lactamase caused severe and protracted disease during an outbreak of E.

Bacteraemia Caused by Escherichia Coli in Cancer Patients at a Specialist Center in Pakistan

International Nuclear Information System (INIS)

Parveen, A.; Sultan, F.; Saleem, S.; Nazeer, S. H.; Raza, A.; Zafar, W.; Nizamuddin, S.; Mahboob, A.

2015-01-01

Objective: To analyse the antimicrobial susceptibility patterns of Escherichia coli bacteraemia among cancer patients, and to assess the risk factors and outcomes of multidrug-resistant Escherichia coli bacteraemia. Methods: The retrospective study was conducted at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, and comprised medical records of patients with Escherichia coli bacteraemia presenting between December 2012 and November 2013. Multivariable logistic regression analyses were used to determine the factors associated with the development and 30-day mortality of multidrug-resistant Escherichia coli bacteraemia. Results: Out of 1603 episodes of bacteraemia, 227(35.6 percent) were caused by E.coli, of which 98(43.2 percent) were multidrug-resistant. In multivariable analysis, age less than 18 years (adjusted odds ratio 3.92; 95 percent confidence interval 1.43-10.68), presence of central venous catheter (adjusted odds ratio 2.12; 95 percent confidence interval 1.04-4.33) and exposure to piperacillin/tazobactam within 90 days prior to infection (adjusted odds ratio 2.37; 95 percent confidence interval 1.15-4.86) were identified as independent risk factors for acquisition of multidrug-resistant Escherichia coli bacteraemia. The overall 30 day mortality rate was 35.2 percent (80/227). Risk factors for mortality were intensive care unit admission (adjusted odds ratio 3.95; 95 percent confidence interval 1.79-8.71) and profound neutropenia (adjusted odds ratio 4.03; 95 percent confidence interval 1.55-10.49). Conclusion: Bloodstream infections with multidrug-resistant Escherichia coli were common in cancer patients. However it was not a predictor of mortality. (author)

[Virulence markers of Escherichia coli O1 strains].

Science.gov (United States)

Makarova, M A; Kaftyreva, L A; Grigor'eva, N S; Kicha, E V; Lipatova, L A

2011-01-01

To detect virulence genes in clinical isolates of Escherichia coli O1 using polymerase chain reaction (PCR). One hundred and twenty strains of E.coli O1 strains isolated from faeces of patients with acute diarrhea (n = 45) and healthy persons (n = 75) were studied. PCR with primers for rfb and fliC genes, which control synthesis of O- and H- antigens respectively, was used. Fourteen virulence genes (pap, aaf, sfa, afa, eaeA, bfpA, ial, hly, cnf, stx1, stx2, lt, st, and aer) were detected by PCR primers. K1-antigen was determined by Pastorex Meningo B/E. coli O1 kit (Bio-Rad). rfb gene controlling O-antigen synthesis in serogroup O1 as well as fliC gene controlling synthesis of H7 and K1 antigens were detected in all strains. Thus all E. coli strains had antigenic structure O1:K1 :H-:F7. Virulence genes aafl, sfa, afa, eaeA, bfpA, ial, hly, cnf, stx1, stx2, lt, and st were not detected. All strains owned pap and aer genes regardless of the presence of acute diarrhea symptoms. It was shown that E. coli O1:KI:H-:F7 strains do not have virulence genes which are characteristic for diarrhea-causing Escherichia. In accordance with the presence of pap and aer genes they could be attributed to uropathogenic Escherichia (UPEC) or avian-pathogenic Escherichia (APEC). It is necessary to detect virulence factors in order to determine E. coli as a cause of intestinal infection.

Metabolic flux balance analysis and the in silico analysis of Escherichia coli K-12 gene deletions

Directory of Open Access Journals (Sweden)

Edwards Jeremy S

2000-07-01

Full Text Available Abstract Background Genome sequencing and bioinformatics are producing detailed lists of the molecular components contained in many prokaryotic organisms. From this 'parts catalogue' of a microbial cell, in silico representations of integrated metabolic functions can be constructed and analyzed using flux balance analysis (FBA. FBA is particularly well-suited to study metabolic networks based on genomic, biochemical, and strain specific information. Results Herein, we have utilized FBA to interpret and analyze the metabolic capabilities of Escherichia coli. We have computationally mapped the metabolic capabilities of E. coli using FBA and examined the optimal utilization of the E. coli metabolic pathways as a function of environmental variables. We have used an in silico analysis to identify seven gene products of central metabolism (glycolysis, pentose phosphate pathway, TCA cycle, electron transport system essential for aerobic growth of E. coli on glucose minimal media, and 15 gene products essential for anaerobic growth on glucose minimal media. The in silico tpi-, zwf, and pta- mutant strains were examined in more detail by mapping the capabilities of these in silico isogenic strains. Conclusions We found that computational models of E. coli metabolism based on physicochemical constraints can be used to interpret mutant behavior. These in silica results lead to a further understanding of the complex genotype-phenotype relation. Supplementary information: http://gcrg.ucsd.edu/supplementary_data/DeletionAnalysis/main.htm

Characterization of Escherichia coli Phylogenetic Groups ...

African Journals Online (AJOL)

Background: Escherichia coli strains mainly fall into four phylogenetic groups (A, B1, B2, and D) and that virulent extra‑intestinal strains mainly belong to groups B2 and D. Aim: The aim was to determine the association between phylogenetic groups of E. coli causing extraintestinal infections (ExPEC) regarding the site of ...

WGS accurately predicts antimicrobial resistance in Escherichia coli

Science.gov (United States)

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...

Transport of Escherichia coli phage through saturated porous media considering managed aquifer recharge.

Science.gov (United States)

Zhang, Wenjing; Li, Shuo; Wang, Shuang; Lei, Liancheng; Yu, Xipeng; Ma, Tianyi

2018-03-01

Virus is one of the most potentially harmful microorganisms in groundwater. In this paper, the effects of hydrodynamic and hydrogeochemical conditions on the transportation of the colloidal virus considering managed aquifer recharge were systematically investigated. Escherichia coli phage, vB_EcoM-ep3, has a broad host range and was able to lyse pathogenic Escherichia coli. Bacteriophage with low risk to infect human has been found extensively in the groundwater environment, so it is considered as a representative model of groundwater viruses. Laboratory studies were carried out to analyze the transport of the Escherichia coli phage under varying conditions of pH, ionic strength, cation valence, flow rate, porous media, and phosphate buffer concentration. The results indicated that decreasing the pH will increase the adsorption of Escherichia coli phage. Increasing the ionic strength, either Na + or Ca 2+ , will form negative condition for the migration of Escherichia coli phage. A comparison of different cation valence tests indicated that changes in transport and deposition were more pronounced with divalent Ca 2+ than monovalent Na + . As the flow rate increases, the release of Escherichia coli phage increases and the retention of Escherichia coli phage in the aquifer medium reduces. Changes in porous media had a significant effect on Escherichia coli phage migration. With increase of phosphate buffer concentration, the suspension stability and migration ability of Escherichia coli phage are both increased. Based on laboratory-scale column experiments, a one-dimensional transport model was established to quantitatively describe the virus transport in saturated porous medium.

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

Science.gov (United States)

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...

The Escherichia coli antiterminator protein BglG stabilizes the 5 ...

Indian Academy of Sciences (India)

Unknown

Keywords. Antitermination; mRNA stability; RNA binding protein ... factor, Rho, and the pBR322 copy number protein, Rop, have been .... Transcription analysis using the oligo- ..... Retarded RNA turnover in Escherichia coli a means of main-.

Escherichia coli survival in waters: Temperature dependence

Science.gov (United States)

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...

Comparative sequence analysis of acid sensitive/resistance proteins in Escherichia coli and Shigella flexneri

Science.gov (United States)

Manikandan, Selvaraj; Balaji, Seetharaaman; Kumar, Anil; Kumar, Rita

2007-01-01

The molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. A preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in Escherichia coli and Shigella flexneri. Here we found the molecular evidence that proved the relationship between E. coli and S. flexneri. Multiple sequence alignment of the gadC coded acid sensitive antiporter showed many conserved residue patterns at regular intervals at the N-terminal region. It was observed that as the alignment approaches towards the C-terminal, the number of conserved residues decreases, indicating that the N-terminal region of this protein has much active role when compared to the carboxyl terminal. The motif, FHLVFFLLLGG, is well conserved within the entire gadC coded protein at the amino terminal. The motif is also partially conserved among other antiporters (which are not coded by gadC) but involved in acid sensitive/resistance mechanism. Phylogenetic cluster analysis proves the relationship of Escherichia coli and Shigella flexneri. The gadC coded proteins are converged as a clade and diverged from other antiporters belongs to the amino acid-polyamine-organocation (APC) superfamily. PMID:21670792

Chromosomal features of Escherichia coli serotype O2:K2, an avian pathogenic E. coli

DEFF Research Database (Denmark)

Jørgensen, Steffen L; Kudirkiene, Egle; Li, Lili

2017-01-01

Escherichia coli causing infection outside the gastrointestinal system are referred to as extra-intestinal pathogenic E. coli. Avian pathogenic E. coli is a subgroup of extra-intestinal pathogenic E. coli and infections due to avian pathogenic E. coli have major impact on poultry production econo...

Comparison of 61 Sequenced Escherichia coli Genomes

DEFF Research Database (Denmark)

Lukjancenko, Oksana; Wassenaar, T. M.; Ussery, David

2010-01-01

Escherichia coli is an important component of the biosphere and is an ideal model for studies of processes involved in bacterial genome evolution. Sixty-one publically available E. coli and Shigella spp. sequenced genomes are compared, using basic methods to produce phylogenetic and proteomics...

lactamase in clinical isolates of Escherichia coli

African Journals Online (AJOL)

Jane

2011-08-22

Aug 22, 2011 ... The beta lactamase enzyme producing E. coli, resistant to β-lactam antibiotics, created many problems ... Key words: Escherichia coli, β-lactamase enzymes, TEM-type extended spectrum ... difficulties in treatment using antibiotics that are currently ... and chloramphenicol (30 µg) (Mast Diagnostics Ltd., UK).

Control analysis of the dependence of Escherichia coli physiology on the H⁺ -ATPase

DEFF Research Database (Denmark)

Jensen, Peter Ruhdal; Michelsen, Ole; Westerhoff, Hans V.

1993-01-01

The H+-ATPase plays a central role in Escherichia coli free-energy transduction and hence in E. coli physiology. We here investigate the extent to which this enzyme also controls the growth rate, growth yield, and respiratory rate of E. coli. We modulate the expression of the atp operon and deter...

Characterization of Escherichia coli Phylogenetic Groups ...

African Journals Online (AJOL)

tract infection (UTI), bacteremia, pneumonia, soft-tissue infection, and ... Keywords: Drug resistance, Escherichia coli, Extraintestinal infections, Polymerase chain reaction, .... gynecology, 12 from orthopedics and 5 from pediatrics units.

Compilation and analysis of Escherichia coli promoter DNA sequences.

OpenAIRE

Hawley, D K; McClure, W R

1983-01-01

The DNA sequence of 168 promoter regions (-50 to +10) for Escherichia coli RNA polymerase were compiled. The complete listing was divided into two groups depending upon whether or not the promoter had been defined by genetic (promoter mutations) or biochemical (5' end determination) criteria. A consensus promoter sequence based on homologies among 112 well-defined promoters was determined that was in substantial agreement with previous compilations. In addition, we have tabulated 98 promoter ...

Detection of diarrheagenic Escherichia coli by use of melting-curve analysis and real-time multiplex PCR.

Science.gov (United States)

Guion, Chase E; Ochoa, Theresa J; Walker, Christopher M; Barletta, Francesca; Cleary, Thomas G

2008-05-01

Diarrheagenic Escherichia coli strains are important causes of diarrhea in children from the developing world and are now being recognized as emerging enteropathogens in the developed world. Current methods of detection are too expensive and labor-intensive for routine detection of these organisms to be practical. We developed a real-time fluorescence-based multiplex PCR for the detection of all six of the currently recognized classes of diarrheagenic E. coli. The primers were designed to specifically amplify eight different virulence genes in the same reaction: aggR for enteroaggregative E. coli, stIa/stIb and lt for enterotoxigenic E. coli, eaeA for enteropathogenic E. coli and Shiga toxin-producing E. coli (STEC), stx(1) and stx(2) for STEC, ipaH for enteroinvasive E. coli, and daaD for diffusely adherent E. coli (DAEC). Eighty-nine of ninety diarrheagenic E. coli and 36/36 nonpathogenic E. coli strains were correctly identified using this approach (specificity, 1.00; sensitivity, 0.99). The single false negative was a DAEC strain. The total time between preparation of DNA from E. coli colonies on agar plates and completion of PCR and melting-curve analysis was less than 90 min. The cost of materials was low. Melting-point analysis of real-time multiplex PCR is a rapid, sensitive, specific, and inexpensive method for detection of diarrheagenic E. coli.

Plasmid-Mediated Quinolone Resistance Genes in Escherichia coli ...

African Journals Online (AJOL)

Erah

PMQR) genes and the prevalence of extended spectrum β-lactamase (ESBL) types in Escherichia coli clinical isolates. Methods: Sixty-one ESBL-producing urinary E. coli isolates were studied. An antibiotic susceptibility test was performed ...

Antimicrobial resistance among commensal Escherichia coli from ...

African Journals Online (AJOL)

Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained from 382 samples.

Antimicrobial resistance among commensal Escherichia coli from ...

African Journals Online (AJOL)

user1

2012-07-19

Jul 19, 2012 ... Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained.

Tranformasi Fragmen Dna Kromosom Xanthomonas Campestris ke dalam Escherichia Coli

Directory of Open Access Journals (Sweden)

Wibowo Mangunwardoyo

2002-04-01

Full Text Available Research on DNA transformation of Xanthomonas campestris into Escherichia coli DH5αα using plasmid vector Escherichia coli (pUC19. was carried out. DNA chromosome was isolated using CTAB method, alkali lysis method was used to isolate DNA plasmid. Both of DNA plasmid and chromosome were digested using restriction enzyme EcoRI. Competent cell was prepared with CaCl2 and heat shock method for transformation procedure. The result revealed transformation obtain 5 white colonies, with transformation frequency was 1,22 x 10-8 colony/competent cell. Electrophoresis analysis showed the DNA fragment (insert in range 0.5 – 7,5 kb. Further research should be carried out to prepare the genomic library to obtain better result of transformant.

Strategies for Protein Overproduction in Escherichia coli.

Science.gov (United States)

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…

Cancerous patients and outbreak of Escherichia coli: an important issue in oncology

OpenAIRE

Joob, Beuy; Wiwanitkit, Viroj

2014-01-01

The widespread of the Escherichia coli outbreak in Europe becomes an important public concern at global level. The infection can be serious and might result in death. The retrospective literature review on this specific topic is performed. In this specific brief article, the author presented and discussed on the problem of Escherichia coli infection in the cancerous patients. This is an actual important issue in medical oncology for the scenario of Escherichia coli epidemic.

Infectious endocarditis caused by Escherichia coli

DEFF Research Database (Denmark)

Lauridsen, Trine Kiilerich; Arpi, Magnus; Fritz-Hansen, Thomas

2011-01-01

Although Escherichia coli is among the most common causes of Gram-negative bacteraemia, infectious endocarditis (IE) due to this pathogen is rare. A 67-y-old male without a previous medical history presented with a new mitral regurgitation murmur and persisting E. coli bacteraemia in spite of broad......-spectrum intravenous antibiotics. Transthoracic and transoesophageal echocardiography revealed a severe mitral endocarditis. E. coli DNA was identified from the mitral valve and the vegetation, and no other pathogen was found. The case was further complicated by spondylodiscitis and bilateral endophthalmitis. Extra...

Translational coupling in Escherichia coli of a heterologous Bacillus subtilis-Escherichia coli gene fusion.

OpenAIRE

Zaghloul, T I; Doi, R H

1986-01-01

The efficient expression in Escherichia coli of the Tn9-derived chloramphenicol acetyltransferase (EC 2.3.1.28) gene fused distal to the promoter and N terminus of the Bacillus subtilis aprA gene was dependent on the initiation of translation from the ribosome-binding site in the aprA gene.

The Escherichia coli transcriptome linked to growth fitness

Directory of Open Access Journals (Sweden)

Bei-Wen Ying

2016-03-01

Full Text Available A series of Escherichia coli strains with varied genomic sequences were subjected to high-density microarray analyses to elucidate the fitness-correlated transcriptomes. Fitness, which is commonly evaluated by the growth rate during the exponential phase, is not only determined by the genome but is also linked to growth conditions, e.g., temperature. We previously reported genetic and environmental contributions to E. coli transcriptomes and evolutionary transcriptome changes in thermal adaptation. Here, we describe experimental details on how to prepare microarray samples that truly represent the growth fitness of the E. coli cells. A step-by-step record of sample preparation procedures that correspond to growing cells and transcriptome data sets that are deposited at the GEO database (GSE33212, GSE52770, GSE61739 are also provided for reference. Keywords: Transcriptome, Growth fitness, Escherichia coli, Microarray

Antibiotic resistance of Verotoxigenic Escherichia coli isolated from vegetables

Directory of Open Access Journals (Sweden)

mojtaba boniadian

2017-01-01

Full Text Available Introduction: Human gastrointestinal disease caused by verotoxigenic Escherichia coli has been diagnosed for recent decades. Escherichia coli O157:H7 is the most important serotype of verotoxigenic Escherichia coli that cause hemolytic uremic syndrome and hemorrhagic colitis in humans. This study was conducted to determine the occurrence of verotoxigenic E. coli and antibiotic resistance of the isolates from vegetables. Materials and methods: A total of 500 fresh vegetable samples were collected randomly from retail shops in Shahrekord, Iran. E. coli was isolated and identified using bacteriological and biochemical tests. PCR method was used to identify the rbfE, stx1, stx2 and eae genes. Also, antibiotic resistance of the isolates was determined by disk diffusion method. Results: The results represented that among 25 isolates possess virulence genes, 40, 12 and 4% of the isolates contained eaeA, STx2, and both genes, respectively. But none of them contained H7, STx1, and rfbE genes. The antibiotic resistance pattern demonstrated that the isolates were highly resistant to Gentamycin and cefotoxime. Discussion and conclusion: The results of this study showed that the presence of verotoxigenic E.coli in vegetables; and high resistance of the isolates to antibiotics could be hazardous for public health.

Analysis of genes involved in glycogen degradation in Escherichia coli.

Science.gov (United States)

Strydom, Lindi; Jewell, Jonathan; Meier, Michael A; George, Gavin M; Pfister, Barbara; Zeeman, Samuel; Kossmann, Jens; Lloyd, James R

2017-02-01

Escherichia coli accumulate or degrade glycogen depending on environmental carbon supply. Glycogen phosphorylase (GlgP) and glycogen debranching enzyme (GlgX) are known to act on the glycogen polymer, while maltodextrin phosphorylase (MalP) is thought to remove maltodextrins released by GlgX. To examine the roles of these enzymes in more detail, single, double and triple mutants lacking all their activities were produced. GlgX and GlgP were shown to act directly on the glycogen polymer, while MalP most likely catabolised soluble malto-oligosaccharides. Interestingly, analysis of a triple mutant lacking all three enzymes indicates the presence of another enzyme that can release maltodextrins from glycogen. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The propagation of Escherichia Coli and of conservative tracers. A comparison

International Nuclear Information System (INIS)

Alexander, I.; Seiler, K.P.

1982-01-01

The propagation of Escherichia Coli (ATCC 11229, Gelsenkirchen) is compared with that of conservative tracers in groundwater. The experiments were performed with injection quantities of 10 7 , 10 8 , 10 10 and 10 11 of Escherichia Coli. Both, bacteria and conservative tracers pass their maximum at the same instant in the observation gauges. With injection quantities of more than 10 8 , the propagation of the Escherichia Coli sets in at the same time as it begins with the dyes. When the quantities range below 10 8 , the propagation begins after that of conservative tracers, because Coli bacteria were measured with a lower degree of detecting sensitivity than the tracers. With Coli injection quantities ranging above 10 10 , an increased filtering of these bacteria can be observed. Coli bacteria propagate more laterally than conservative tracers, however it could not be proved that this lateral propagation depends on the bacteria concentration. (orig.) [de

76 FR 20542 - Escherichia coli

Science.gov (United States)

2011-04-13

... beef, Escherichia coli and coliphages were found in chicken, fresh pork, fresh oyster, fresh mushrooms, lettuce, chicken pot pie, biscuit dough, deli loaf, deli roasted turkey, and package roasted chicken... surfaces, and in foods such as ground beef, pork sausage, chicken, oysters, cheese, fresh mushrooms, and...

Multiplex polymerase chain reaction for identification of Escherichia coli, Escherichia albertii and Escherichia fergusonii.

Science.gov (United States)

Lindsey, Rebecca L; Garcia-Toledo, L; Fasulo, D; Gladney, L M; Strockbine, N

2017-09-01

Escherichia coli, Escherichia albertii, and Escherichia fergusonii are closely related bacteria that can cause illness in humans, such as bacteremia, urinary tract infections and diarrhea. Current identification strategies for these three species vary in complexity and typically rely on the use of multiple phenotypic and genetic tests. To facilitate their rapid identification, we developed a multiplex PCR assay targeting conserved, species-specific genes. We used the Daydreamer™ (Pattern Genomics, USA) software platform to concurrently analyze whole genome sequence assemblies (WGS) from 150 Enterobacteriaceae genomes (107 E. coli, 5 Shigella spp., 21 E. albertii, 12 E. fergusonii and 5 other species) and design primers for the following species-specific regions: a 212bp region of the cyclic di-GMP regulator gene (cdgR, AW869_22935 from genome K-12 MG1655, CP014225) for E. coli/Shigella; a 393bp region of the DNA-binding transcriptional activator of cysteine biosynthesis gene (EAKF1_ch4033 from genome KF1, CP007025) for E. albertii; and a 575bp region of the palmitoleoyl-acyl carrier protein (ACP)-dependent acyltransferase (EFER_0790 from genome ATCC 35469, CU928158) for E. fergusonii. We incorporated the species-specific primers into a conventional multiplex PCR assay and assessed its performance with a collection of 97 Enterobacteriaceae strains. The assay was 100% sensitive and specific for detecting the expected species and offers a quick and accurate strategy for identifying E. coli, E. albertii, and E. fergusonii in either a single reaction or by in silico PCR with sequence assemblies. Published by Elsevier B.V.

Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the regulator AcrR from Escherichia coli

International Nuclear Information System (INIS)

Li, Ming; Qiu, Xi; Su, Chih-Chia; Long, Feng; Gu, Ruoyu; McDermott, Gerry; Yu, Edward W.

2006-01-01

The transcriptional regulator AcrR from Escherichia coli has been cloned, overexpressed, purified and crystallized and X-ray diffraction data have been collected to a resolution of 2.5 Å. This paper describes the cloning, expression, purification and preliminary X-ray data analysis of the AcrR regulatory protein. The Escherichia coli AcrR is a member of the TetR family of transcriptional regulators. It regulates the expression of the AcrAB multidrug transporter. Recombinant AcrR with a 6×His tag at the C-terminus was expressed in E. coli and purified by metal-affinity chromatography. The protein was crystallized using hanging-drop vapor diffusion. X-ray diffraction data were collected from cryocooled crystals at a synchrotron light source. The best crystal diffracted to 2.5 Å. The space group was determined to be P3 2 , with unit-cell parameters a = b = 46.61, c = 166.16 Å

Epidemiology and clinical manifestations of enteroaggregative Escherichia coli

DEFF Research Database (Denmark)

Hebbelstrup Jensen, Betina; Olsen, Katharina E P; Struve, Carsten

2014-01-01

Enteroaggregative Escherichia coli (EAEC) represents a heterogeneous group of E. coli strains. The pathogenicity and clinical relevance of these bacteria are still controversial. In this review, we describe the clinical significance of EAEC regarding patterns of infection in humans, transmission...

Photoreactivable sector of lethal damage in ultraviolet-irradiated Escherichia coli cells

International Nuclear Information System (INIS)

Balgavy, P.

1976-01-01

The photoreactivable sector of lethal damage in Escherichia coli Bsub(s-1), Escherichia coli B/r Hcr - and Escherichia coli B/r Hcr + cells after ultraviolet irradiation at 254 nm is 0.823 +- 0.004, 0.70 +- 0.01 and 0.53 +- 0.06, respectively, at 99% confidence limits. For the low values of the photoreactivable sector in the B/r Hcr - and B/r Hcr + strains are likely to be responsible dark repair processes which eliminate lethal damage, brought about by pyrimidine dimers, preferably in comparison with lethal damage caused by photoproducts of another type. (author)

Escherichia coli as a probiotic?

NARCIS (Netherlands)

Jansen, GJ; Wildeboer-Veloo, ACM; van der Waaij, D; Degener, JE

1998-01-01

The influence of oral treatment with a suspension of non-pathogenic Escherichia coli cells (commercially available as: Symbioflor II(R)) on the morphological composition of the gut microflora and on the systemic humoral immune response (the IgG-, IgA- and IgM-isotype) against the bacterial cells in

PENGARUH PERASAN DAUN BELIMBING WULUH (Averrhoa bilimbi TERHADAP PERTUMBUHAN BAKTERI Escherichia coli PATOGEN

Directory of Open Access Journals (Sweden)

Fitrotin Azizah

2017-12-01

abstract  (Averrhoa bilimbi is one of the plants that can be used as an antibacterial, good flowers, stems, leaves and stems have benefits and efficacy. Chemical constituents of the leaves starfruit are tannins, flavonoids, saponins. The active ingredient in the leaves starfruit is tannin. Escherichia coli is a bacterium that causes diarrhea. From the above discussion, the authors raised the theme of Influence starfruit juice of the leaves on the growth of pathogenic E. coli bacteria. Formulation of the problem researchers is whether there is influence starfruit juice of the leaves on the growth of Escherichia coli pathogens. This study aims to determine the concentration that could inhibit and kill Esherichia coli Escherichia coli. This research is experimental. The sample used is leaf green starfruit not so young in a fresh state taken in the area around the boarding author Sutorejo 11B stay. In this study, the sample size for each treatment as much as 3 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% and C (control. Independent variables are starfruit juice of the leaves, while the dependent variable growth of Escherichia coli. When the study carried out in January and July 2012. Data on the effect of starfruit juice of the leaves on the growth of Escherichia coli tested by laboratory examination and data collection techniques using Chi-Square 0:05. Based on the results it appears that at a concentration of 100% and 90% were able to kill the bacteria Escherichia coli, whereas the inhibitory power ranging from a concentration of 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%. From Chi-Square test was obtained λ2 count Escherichia coli pathogenic bacteria. Keyword : Leaves starfruit, E. Coli

Crystallization and preliminary X-ray diffraction analysis of diaminopimelate epimerase from Escherichia coli

International Nuclear Information System (INIS)

Hor, Lilian; Dobson, Renwick C. J.; Dogovski, Con; Hutton, Craig A.; Perugini, Matthew A.

2009-01-01

Diaminopimelate (DAP) epimerase, an enzyme in the lysine-biosynthetic pathway, is a promising target for antibiotic development against pathogenic bacteria. Here, the cloning, expression, purification, crystallization and preliminary diffraction analysis of DAP epimerase from E. coli are reported. Diaminopimelate (DAP) epimerase (EC 5.1.1.7) catalyzes the penultimate step of lysine biosynthesis in bacteria and plants, converting l,l-diaminopimelate to meso-diaminopimelate. Here, the cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of DAP epimerase from Escherichia coli are presented. Crystals were obtained in space group P4 1 2 1 2 and diffracted to 2.0 Å resolution, with unit-cell parameters a = b = 89.4, c = 179.6 Å. Molecular replacement was conducted using Bacillus anthracis DAP epimerase as a search model and showed the presence of two molecules in the asymmetric unit, with an initial R free of 0.456 and R work of 0.416

Fosfomycin Resistance in Escherichia coli, Pennsylvania, USA.

Science.gov (United States)

Alrowais, Hind; McElheny, Christi L; Spychala, Caressa N; Sastry, Sangeeta; Guo, Qinglan; Butt, Adeel A; Doi, Yohei

2015-11-01

Fosfomycin resistance in Escherichia coli is rare in the United States. An extended-spectrum β-lactamase-producing E. coli clinical strain identified in Pennsylvania, USA, showed high-level fosfomycin resistance caused by the fosA3 gene. The IncFII plasmid carrying this gene had a structure similar to those found in China, where fosfomycin resistance is commonly described.

Neonatal infections caused by Escherichia coli at the National ...

African Journals Online (AJOL)

Background: Escherichia coli (E.coli) has been implicated as a common cause of both early and late onset neonatal infections. The emergence of different strains of E.coli that are multiply resistant to commonly used antibiotics has made continuous antibiotics surveillance relevant. Knowledge about common infections ...

neonatal infections caused by escherichia coli at the national

African Journals Online (AJOL)

boaz

Background: Escherichia coli (E.coli) has been implicated as a common cause of both early and late onset neonatal infections. The emergence of different strains of E.coli that are multiply resistant to commonly used antibiotics has made continuous antibiotics surveillance relevant. Knowledge about common infections ...

the occurrence of escherichia coli o157:h7 in market and abattoir

African Journals Online (AJOL)

user

Escherichia coli O157:H7 is a newly emerging pathogen frequently associated with the consumption of foods of ... KEY WORDS: E. coli O157:H7, Pathogen, Abattoir, Market, and Infections ..... pathogen. Escherichia coli O157:H7 as a model of.

ESCHERICHIA COLI AND STAPHYLOCOCCUS AUREUS

African Journals Online (AJOL)

DR. AMINU

ABSTRACT. The bio-effects of the ethanol extracts from the leaf and stem of Momordica charantia were studied with the view to ascertain the medical usefulness ascribed to the plant by the locals. The plant parts, stem and leaf, revealed remarkable activity against Escherichia coli and Staphlococcus aureus. The leaves ...

Conjugal Pairing in Escherichia Coli

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

Emergence and mechanism of carbapenem-resistant Escherichia coli in Henan, China, 2014

Directory of Open Access Journals (Sweden)

Wen-juan Liang

2018-05-01

Full Text Available The emergence and dissemination of carbapenem-resistant Escherichia coli (E. coli strains is a main risk for global public health, but little is known of carbapenemase producing E. coli in Henan, China. The study was undertaken to investigate the prevalence and mechanism of carbapenem-resistant E. coli strains in a hospital in Xinxiang, Henan, China, 2014. A total of 5 carbapenemase-producing E. coli strains were screened from 1014 isolates. We found that they were all resistant to meropenem and imipenem. Amikacin showed the best sensitivity, with gentamicin coming up next. The positive rate of blaNDM was 80% (4/5. The sequencing results showed that two isolates belonged to blaNDM-1 whereas other 2 isolates carried the blaNDM-5. Other carbapenemase genes including blaIMP, blaVIM, blaKPC and blaOXA-48 were not detected. The blaCTX-M-15, blaTEM-1, sul2, aad, and aac(6”–Ib–cr were also detected. MLST analysis showed that NDM-producing E. coli were sporadic. Conjugation test indicated blaNDM could be transferred. In conclusion, the blaNDM was the principal resistance mechanism of carbapenem-resistant E. coli in the hospital, Henan, China. Keywords: blaNDM, Carbapenem-resistant, Escherichia coli

Increased multi-drug resistant Escherichia coli from hospitals in ...

African Journals Online (AJOL)

Background: Multidrug-resistant Escherichia coli (MDR E. coli) has become a major public health concern in Sudan and many countries, causing failure in treatment with consequent huge health burden. Objectives: To determine the prevalence and susceptibility of MDR E. coli isolated from patients in hospitals at Khartoum ...

Reconstitution of active mycobacterial binuclear iron monooxygenase complex in Escherichia coli.

Science.gov (United States)

Furuya, Toshiki; Hayashi, Mika; Kino, Kuniki

2013-10-01

Bacterial binuclear iron monooxygenases play numerous physiological roles in oxidative metabolism. Monooxygenases of this type found in actinomycetes also catalyze various useful reactions and have attracted much attention as oxidation biocatalysts. However, difficulties in expressing these multicomponent monooxygenases in heterologous hosts, particularly in Escherichia coli, have hampered the development of engineered oxidation biocatalysts. Here, we describe a strategy to functionally express the mycobacterial binuclear iron monooxygenase MimABCD in Escherichia coli. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of the mimABCD gene expression in E. coli revealed that the oxygenase components MimA and MimC were insoluble. Furthermore, although the reductase MimB was expressed at a low level in the soluble fraction of E. coli cells, a band corresponding to the coupling protein MimD was not evident. This situation rendered the transformed E. coli cells inactive. We found that the following factors are important for functional expression of MimABCD in E. coli: coexpression of the specific chaperonin MimG, which caused MimA and MimC to be soluble in E. coli cells, and the optimization of the mimD nucleotide sequence, which led to efficient expression of this gene product. These two remedies enabled this multicomponent monooxygenase to be actively expressed in E. coli. The strategy described here should be generally applicable to the E. coli expression of other actinomycetous binuclear iron monooxygenases and related enzymes and will accelerate the development of engineered oxidation biocatalysts for industrial processes.

Research on killing Escherichia Coli by reactive oxygen species based on strong ionization discharging plasma

International Nuclear Information System (INIS)

Li, Y J; Tian, Y P; Zhang, Z T; Li, R H; Cai, L J; Gao, J Y

2013-01-01

Reactive oxygen species solution produced by strong ionization discharging plasma was used to kill Escherichia coli by spraying. Several effect factors such as pH value, solution temperature, spraying time and exposure time were observed in this study, and their effects on killing rate of Escherichia coli were discussed and analysed. Results show that the treating efficiency of ROS solution for Escherichia coli is higher in alkaline solution than that in acid solution. The killing rate of Escherichia coli increases while the spraying time and exposure time are longer and the temperature is lower. The effects of different factors on killing rate of Escherichia coli are as follows: spraying time > pH value > exposure time > solution temperature.

Phytochemical analysis and antimicrobial activity of baobab (Adansonia digitata leaves and stem bark extracts on Staphylococcus aureus and Escherichia coli

Directory of Open Access Journals (Sweden)

Mohammed Sani Sambo Datsugwai

2017-05-01

Full Text Available The phytochemical analysis and antibacterial activity of methanolic and ethanolic leaf and stem bark extracts of baobab tree on Escherichia coli and Staphylococcus aureus were carried out using agar well diffusion method. The clinical bacterial isolates of Escherichia coli and Staphylococcus aureus were obtained from Microbiology laboratory, Kaduna State University, Kaduna. The bacteria isolates were re-confirmed and identified based on their morphology, cultural characteristics and biochemical tests. The bacteria isolates were confirmed to be Escherichia coli and Staphylococcus aureus. The phytochemical analysis revealed the presence of Alkaloids, Saponins, Flavonoids, Tannins and Terpenoids. The methanolic leaf extract showed a wide range of activity on test isolates, with varying zones of inhibitions as 12 mm, 10 mm, 7 mm, and 4 mm against Staphylococcus aureus and 13 mm, 9 mm, 7 mm, and 3 mm against Escherichia coli at concentration of 1000 mg/ml, 500 mg/ml, 200 mg/ml and 100 mg/ml respectively. The ethanolic leaf extract also showed a wide range of activity on test isolates with varying zones of inhibitions, such as 11mm, 6mm, 5mm and 3mm against S. aureus and 8mm, 7mm, 5mm, and 4mm against E. coli at the concentration of 1000 mg/ml, 500mg/ml, 200 mg/ml and 100mg/ml for each respectively. The methanolic stem bark extract showed less antibacterial activity against the test isolates with the inhibition of 5mm and 4mm against S. aureus and 4mm and 3mm against E.coli at concentration of 1000 mg/ml and 500 mg/ml respectively with no zones of inhibition at concentration of 200 mg/ml and 100mg/ml. The ethanolic stem bark extract also showed no antibacterial activity with no zones of inhibition against the test isolates at concentration of 1000 mg/ml, 500 mg/ml, 200mg/ml and 100 mg/ml. The methanolic leaf extract inhibited the growth of S. aureus and E.coli at concentration of 100 mg/ml with minimum bactericidal concentration at 100 mg/ml. The

Contaminated Stream Water as Source for Escherichia coli O157 Illness in Children.

Science.gov (United States)

Probert, William S; Miller, Glen M; Ledin, Katya E

2017-07-01

In May 2016, an outbreak of Shiga toxin-producing Escherichia coli O157 infections occurred among children who had played in a stream flowing through a park. Analysis of E. coli isolates from the patients, stream water, and deer and coyote scat showed that feces from deer were the most likely source of contamination.

Alterations induced in Escherichia Coli cells by gamma radiation

International Nuclear Information System (INIS)

Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da; Jesus, E.F.O. de; Lopes, R.T.; Carlin, N.; Toledo, E.S.

2007-01-01

Modifications occurred in Escherichia coli cells exposed to gamma radiation ( 60 Co source) were investigated. The irradiations were done at the LIN-COPPE laboratory of the UFRJ and the analysis at the Biology Department of the UTFPR. The E. coli cells were irradiated with 30, 60, 90, 120, 150, 180, 210, 240, 300, 480, 600 e 750 Gy doses. The samples were analyzed with Gram-stain, biochemical tests in EPM, MIO and Lysine Broth, Simmons Cytrate Medium and Rhamnose Broth, antibiogram and isolation of auxotrophic mutants. It was observed that for the received doses the E. coli did not show morphological alterations in the tests. Some E. Coli cells showed to be able to deaminade the L-tryptophan or they changed their sensibility for amoxillin and cephaloonine after the irradiation. The existence of aauxotrophic mutants after irradiation was also verified. (author)

ESBL-Producing Escherichia coli

DEFF Research Database (Denmark)

Hertz, Frederik Boetius

Urinary tract infection (UTI) is one the most common bacterial infections and is regularly treated in primary health care. The most common cause of UTI is extraintestinal pathogenic Escherichia coli (ExPEC) already present in the intestinal microflora, often as the dominating strain. Resistance...... in E.coli is increasing and especially isolates producing Extended-Spectrum Beta-Lactamases (ESBL) have been reported worldwide. Treatment of UTI is usually initiated by the general practitioners and a significant proportion of clinical isolates are now resistant to first line antibiotics. The global...... to investigate (i) antibiotics involved in selection of ESBL-producing E.coli, in an experimental mouse model in vivo, (ii) risk factors for UTI with ESBL-producing E.coli and (iii) to describe the phylogenetic composition of E.coli populations with different resistance patterns. We found that different...

Analysis of the human intestinal epithelial cell transcriptional response to Lactobacillus acidophilus, Lactobacillus salivarius, Bifidobacterium lactis and Escherichia coli

DEFF Research Database (Denmark)

Putaala, H; Barrangou, R; Leyer, G J

2010-01-01

a comparative analysis of the global in vitro transcriptional response of human intestinal epithelial cells to Lactobacillus acidophilus NCFM™, Lactobacillus salivarius Ls-33, Bifidobacterium animalis subsp. lactis 420, and enterohaemorrhagic Escherichia coli O157:H7 (EHEC). Interestingly, L. salivarius Ls-33...

Multiplex PCR Assay for Identification of Human Diarrheagenic Escherichia coli

OpenAIRE

Toma, Claudia; Lu, Yan; Higa, Naomi; Nakasone, Noboru; Chinen, Isabel; Baschkier, Ariela; Rivas, Marta; Iwanaga, Masaaki

2003-01-01

A multiplex PCR assay for the identification of human diarrheagenic Escherichia coli was developed. The targets selected for each category were eae for enteropathogenic E. coli, stx for Shiga toxin-producing E. coli, elt and est for enterotoxigenic E. coli, ipaH for enteroinvasive E. coli, and aggR for enteroaggregative E. coli. This assay allowed the categorization of a diarrheagenic E. coli strain in a single reaction tube.

lactamases genes among0 Escherichia coli from patients with ...

African Journals Online (AJOL)

-lactamases (ESBLs) that mediate resistance to b-lactam drugs among Escherichia coli and other uropathogens have been reported worldwide. However, there is little information on the detection of ESBLs genes in E. coli from patients with ...

Diarrheagenic Escherichia coli Markers and Phenotypes among Fecal E. coli Isolates Collected from Nicaraguan Infants ▿

OpenAIRE

Reyes, Daniel; Vilchez, Samuel; Paniagua, Margarita; Colque-Navarro, Patricia; Weintraub, Andrej; Möllby, Roland; Kühn, Inger

2010-01-01

We analyzed the prevalence of diarrheagenic Escherichia coli (DEC) markers and common phenotypes in 2,164 E. coli isolates from 282 DEC-positive samples. Enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC) were very diverse and were not correlated with diarrhea. Enterotoxigenic E. coli (ETEC) estA and enterohemorrhagic E. coli (EHEC) belonged to a few phenotypes and were significantly correlated with diarrhea.

Escherichia coli growth modeling using neural network | Shamsudin ...

African Journals Online (AJOL)

technique that has the ability to predict with efficient and good performance. Using NARX, a highly accurate model was developed to predict the growth of Escherichia coli (E. coli) based on pH water parameter. The multiparameter portable sensor and spectrophotometer data were used to build and train the neural network.

Surface display of Salmonella epitopes in Escherichia coli and Staphylococcus carnosus.

Science.gov (United States)

Nhan, Nguyen Thanh; Gonzalez de Valdivia, Ernesto; Gustavsson, Martin; Hai, Truong Nam; Larsson, Gen

2011-04-11

Salmonella enterica serotype Enteritidis (SE) is considered to be one of the most potent pathogenic Salmonella serotypes causing food-borne disease in humans. Since a live bacterial vaccine based on surface display of antigens has many advantages over traditional vaccines, we have studied the surface display of the SE antigenic proteins, H:gm and SefA in Escherichia coli by the β-autotransporter system, AIDA. This procedure was compared to protein translocation in Staphylococcus carnosus, using a staphylococci hybrid vector earlier developed for surface display of other vaccine epitopes. Both SefA and H:gm were translocated to the outer membrane in Escherichia coli. SefA was expressed to full length but H:gm was shorter than expected, probably due to a proteolytic cleavage of the N-terminal during passage either through the periplasm or over the membrane. FACS analysis confirmed that SefA was facing the extracellular environment, but this could not be conclusively established for H:gm since the N-terminal detection tag (His6) was cleaved off. Polyclonal salmonella antibodies confirmed the sustained antibody-antigen binding towards both proteins. The surface expression data from Staphylococcus carnosus suggested that the H:gm and SefA proteins were transported to the cell wall since the detection marker was displayed by FACS analysis. Apart from the accumulated knowledge and the existence of a wealth of equipment and techniques, the results indicate the selection of E. coli for further studies for surface expression of salmonella antigens. Surface expression of the full length protein facing the cell environment was positively proven by standard analysis, and the FACS signal comparison to expression in Staphylococcus carnosus shows that the distribution of the surface protein on each cell was comparatively very narrow in E. coli, the E. coli outer membrane molecules can serve as an adjuvant for the surface antigenic proteins and multimeric forms of the SefA protein

FTIR nanobiosensors for Escherichia coli detection

Directory of Open Access Journals (Sweden)

Stefania Mura

2012-07-01

Full Text Available Infections due to enterohaemorrhagic E. coli (Escherichia coli have a low incidence but can have severe and sometimes fatal health consequences, and thus represent some of the most serious diseases due to the contamination of water and food. New, fast and simple devices that monitor these pathogens are necessary to improve the safety of our food supply chain. In this work we report on mesoporous titania thin-film substrates as sensors to detect E. coli O157:H7. Titania films treated with APTES ((3-aminopropyltriethoxysilane and GA (glutaraldehyde were functionalized with specific antibodies and the absorption properties monitored. The film-based biosensors showed a detection limit for E. coli of 1 × 102 CFU/mL, constituting a simple and selective method for the effective screening of water samples.

Hemolytic porcine intestinal Escherichia coli without virulence-associated genes typical of intestinal pathogenic E. coli.

Science.gov (United States)

Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

2011-12-01

Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli.

Annual Surveillance Summary: Escherichia coli (E. coli) Infections in the Military Health System (MHS), 2015

Science.gov (United States)

2017-03-01

Annual Surveillance Summary: Escherichia coli ( E . coli ) Infections in the Military Health System (MHS...or position of the Department of the Navy, Department of Defense, nor the U.S. Government. i i E . coli in the MHS: Annual Summary 2015 Prepared...March 2017 EpiData Center Department NMCPHC-EDC-TR-187-2017 ii ii E . coli in the MHS: Annual Summary 2015 Prepared March 2017 EpiData

Escherichia coli in broiler chickens with airsacculitis

Directory of Open Access Journals (Sweden)

Leandro S. Machado

2014-09-01

Full Text Available ABSTRACT. Machado L.S., do Nascimento E.R., Pereira V.L.A., Abreu D.L.C., Gouvea R. & Santos L.M.M. 2014. [Escherichia coli in broiler chickens with airsacculitis.] Escherichia coli em frangos de corte com aerossaculite. Revista Brasileira de Medicina Veterinária, 36(3:261-265, 2014. Departamento de Medicina Veterinária Preventiva e Saúde Pública, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Dr. Vital Brazil Filho 64, Vital Brazil, Niterói, RJ 24230-340, Brazil. E-mail: leandromachadovet@yahoo.com.br The Brazilian poultry industry grows each year and becomes increasingly representative in the production and export of products. The health care with poultry have accompanied and favored this evolution, however, respiratory agents that affect the weight and carcass quality, continue to cause great damage to the poultry industry. Airsacculitis is considered the main cause of total and partial condemnation of carcasses of broilers, and has been attributed to Mycoplasmosis mostly caused by Mycoplasma gallisepticum (MG and Mycoplasma synoviae (MS and Escherichia coli. The aim of this study was to relate the positivity of MG / MS and E. coli detected by PCR as a risk factor for airsacculitis in condemnation of broilers in Health Inspection Service. We studied 30 broiler poultry slaughtered in a slaughterhouse under Federal Sanitary Inspection, located in the State of Rio de Janeiro. 30 chickens were randomly collected from different lots and tracheas obtained in each PCR. DNA was extracted by phenol-chloroform method and amplified using pairs of “primer”specific for MG, MS and E. coli. Of the 30 chickens analyzed by PCR, 30% (9/30 had lesions in air sacs. None of the birds showed infection with MG and/or MS PCR, however 33.3% (3/9 birds were positive for airsacculitis iss gene from E.coli. E.coli found in broiler chickens that were negative for mycoplasma airsacculitis, implying the presence of such bacteria may be sufficient

Escherichia coli enteroagregativa como agente provocador de diarreia persistente: modelo experimental utilizando microscopia óptica de luz Escherichia coli enteroagregativa como agente provocador de diarrea persistente: modelo experimental utilizando microscopia óptica de luz Enteroaggregative Escherichia coli as a cause of persistent diarrhea: an experimental model using light microscopy

Directory of Open Access Journals (Sweden)

Jacy Alves B. de Andrade

2011-03-01

de órgano in vitro de fragmentos de mucosa ileal y del colon. Fueron analizadas las interacciones entra las distintas cepas de EAEC y las mucosas ileal y del colon. RESULTADOS: El análisis por ML indicó asociación de estos microorganismos con el epitelio, provocando alteraciones. Las cepas estudiadas adhirieron a ambas regiones evaluadas: intestino delgado distal y grueso y causaron alteraciones, especialmente en aquellas áreas donde interactuaron directamente con el epitelio. En el íleo, algunas regiones mostraron internalización secundaria. CONCLUSIÓN: Estos agentes pueden causar diarrea persistente mediante alteraciones en el intestino delgado, donde ocurren las funciones digestivo-absortibas. Las lesiones inflamatorias descritas en la mucosa del colon podrían explicar la colitis descrita en algunos niños infectados por EAEC.OBJECTIVE: To examine the interactions of Enteroaggregative Escherichia coli strains with small and large intestinal mucosa, in order to detect potential alterations in both regions of the digestive tract. METHODS: Enteroaggregative Escherichia coli strains, isolated from stools of infants with persistent diarrhea and the prototype strain 042 (O44:H18, isolated from a child with diarrhea in Lima, Peru (positive control, were analised by light microscopy after in vitro organ culture assay of ileal and colonic mucosa. The interactions between the different enteroaggregative Escherichia coli strains and the ileal and colonic mucosa were analysed. RESULTS: Light microscopy analysis suggested an association of enteroaggregative Escherichia coli strains with the epithelium, inducing alterations. These bacteria adhered to both small and large bowel mucosa. The enteroaggregative Escherichia coli strains induced alterations in those areas where they were directly interacting with the epithelium. In the ileum, some areas showed a secondary internalization. CONCLUSIONS: The enteroaggregative Escherichia coli strains could cause persistent

Thioredoxin from Escherichia coli

International Nuclear Information System (INIS)

Holmgren, A.; Ohlsson, I.; Grankvist, M.L.

1978-01-01

A competition radioimmunoassay for Escherichia coli thioredoxin using 125 I-labeled thioredoxin-S 2 and a double antibody technique was developed. The method permits determination of picomole amounts of thioredoxin in crude cell extracts and was used to study the localization of thioredoxin cell fractions. E. coli B was calculated to have approximately 10,000 copies of thioredoxin per cell mainly located in the soluble fraction after separation of the membrane and soluble fractions by gentle lysis and centrifugation. E. coli B tsnC mutants which are defective in the replication of phage T7 DNA in vivo and in vitro were examined for their content of thioredoxin. E. coli B tsnC 7004 contained no detectable level of thioredoxin in cell-free extracts examined under a variety of conditions. The results strongly suggest that tsnC 7004 is a nonsense or deletion mutant. Two other E. coli tsnC mutants, 7007 and 7008, contained detectable levels of thioredoxin in crude extracts as measured by thioredoxin reductase and gave similar immunoprecipitation reactions as the parent strain B/1. By radioimmunoassay incompletely cross-reacting material was present in both strains. These results show that tsnC 7007 and 7008 belong to a type of thioredoxin mutants with missence mutations in the thioredoxin gene affecting the function of thioredoxin as subunit in phage T7 DNA polymerase

ANTIMICIROBIAL SUSCEPTIBILITY PATTERNS OF Escherichia coli ...

African Journals Online (AJOL)

DR. AMINU

A total of 56 and 24 strains of E. coli and Shigella sp. isolated from children less than five years with diarrhoea attending 3 ... parasitic infections, as well as food intolerance, reaction to ..... Escherichia coil 0157:H7 as a model of entry of a new.

Distribution of Diverse Escherichia coli between Cattle and Pasture

OpenAIRE

NandaKafle, Gitanjali; Seale, Tarren; Flint, Toby; Nepal, Madhav; Venter, Stephanus N.; Brözel, Volker S.

2017-01-01

Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isola...

(ESBL) producing Escherichia coli and Klebsiella pneumoniae

African Journals Online (AJOL)

use

2011-11-21

Nov 21, 2011 ... the most common serious bacterial infections in infants ... UTI is a common cause of morbidity .... of ESBL and non-ESBL producing Escherichia coli and Klebsiella pneumonia. ... in hospital and community acquired infections.

Antimicrobial susceptibilities of avian Escherichia coli isolates in ...

African Journals Online (AJOL)

Colibacillosis is a poultry disease of economic importance in Iran and all around the world. The aim of this study is to test the antibiotic sensitivity of Escherichia coli strains which were isolated in Tabriz. A total of 100 E. coli strains isolated from avian colibacillosis of 50 farms from 2008 to 2009 in Tabriz, were investigated for ...

PART I. ESCHERICHIA COLI

Directory of Open Access Journals (Sweden)

Sanaa Mahdi Oraibi

2016-11-01

Full Text Available The presence of Escherichia coli in the air of facilities involved in management and composting of post-slaughter poultry wastes in selected plants of West Western Pomerania region was studied. Measurements were made on four dates in a variety of weather conditions during the year. The study was conducted at 5 objects that differ in the type of waste and the degree of preparation for composting. These were: chemical treatment and preliminary processing plant, liquid wastes reservoir, platform for preparation of materials for composting, storage of biological sediments, and composting facility. Measurement of bacteria count was carried out in accordance with the applicable procedures on selective chromogenic TBX medium. The assays revealed the presence of E. coli at all test objects, but not always on all measurement dates. It has been shown that the presence of E. coli was from 20 to 3047 CFU∙m-3 of air, although the largest quantities were most frequently detected in the air of the building for post-slaughter waste pre-treatment in chemical treatment plant.

Findings of Escherichia coli and Enterococcus spp. in homemade cheese

Directory of Open Access Journals (Sweden)

Tambur Zoran

2007-01-01

Full Text Available During the period from February until March 2004, 108 samples of soft cheese originating from markets of Pancevo, Subotica and Belgrade were examined. Microbiological analyses of the cheese samples to the presence of Escherichia coli was performed using methods described in the Regulations on methods for performing microbiological analyses and super analyses of consumer articles, while the presence of bacteria Enteroccocus spp. was performed on the dexter agar. From 108 samples of soft cheese from the territories of Pancevo, Belgrade and Subotica were isolated: Enterococcus spp. from 96% and Escherichia coli from 69%, cheese samples. Verocytotoxic E.coli was not isolated from any of the taken cheese samples.

Escherichia coli pyomyositis in an immunocompromised host.

Science.gov (United States)

Sharma, Umesh; Schwan, William R; Agger, William A

2011-08-01

Pyomyositis due to Escherichia coli (E. coil) is rarely reported in immunocompromised patients with hematological malignancy. We present a case report of a 34-year-old man who developed E. coli pyomyositis as a complication of acute myelogenous leukemia (AML). Magnetic resonance imaging (MRI) of the right hip suggested myofascial infection of the gluteal muscles, and a needle muscle aspiration grew E. coli phylogenetic group B2. The patient responded to intravenous piperacillin/tazobactam followed by prolonged oral levofloxacin. Pyomyositis should be suspected in all immunocompromised patients complaining of muscle pain and may exhibit signs of localized muscle infection. Appropriate antibiotic therapy targeting fluoroquinolone-resistant E. coli should be considered for initial empiric therapy of pyomyositis in immunocompromised patients.

Infectious endocarditis caused by Escherichia coli

DEFF Research Database (Denmark)

Lauridsen, Trine Kiilerich; Arpi, Magnus; Fritz-Hansen, Thomas

2011-01-01

Although Escherichia coli is among the most common causes of Gram-negative bacteraemia, infectious endocarditis (IE) due to this pathogen is rare. A 67-y-old male without a previous medical history presented with a new mitral regurgitation murmur and persisting E. coli bacteraemia in spite of broad......-spectrum intravenous antibiotics. Transthoracic and transoesophageal echocardiography revealed a severe mitral endocarditis. E. coli DNA was identified from the mitral valve and the vegetation, and no other pathogen was found. The case was further complicated by spondylodiscitis and bilateral endophthalmitis. Extra......-intestinal pathogenic E. coli (ExPEC) are able to colonize tissue outside the gastrointestinal tract and contain a variety of virulence factors that may enable the pathogens to invade and induce infections in the cardiac endothelia. In these cases echocardiography as the imaging technology is of paramount importance...

Mutagenic DNA repair in Escherichia coli

International Nuclear Information System (INIS)

Bridges, B.A.; Sharif, Firdaus

1986-01-01

The authors report a study of the misincorporation step in excision proficient umuC Escherichia coli as revealed by delayed photoreversal and show that it parallels the loss of photoreversibility of mutations induced in isogenic umu + bacteria; in both cases the end-point was mutation to streptomycin resistance. (author)

Proteomic analysis of the response of Escherichia coli to short-chain fatty acids.

Science.gov (United States)

Rodríguez-Moyá, María; Gonzalez, Ramon

2015-06-03

Given their simple and easy-to-manipulate chemical structures, short-chain fatty acids (SCFAs) are valuable feedstocks for many industrial applications. While the microbial production of SCFAs by engineered Escherichia coli has been demonstrated recently, productivity and yields are limited by their antimicrobial properties. In this work, we performed a comparative proteomic analysis of E. coli under octanoic acid stress (15 mM) and identified the underlying mechanisms of SCFA toxicity. Out of a total of 33 spots differentially expressed at a p-value ≤ 0.05, nine differentially expressed proteins involved in transport and structural roles (OmpF, HPr, and FliC), oxidative stress (SodA, SodB, and TrxA), protein synthesis (PPiB and RpsA) and metabolic functions (HPr, PflB) were selected for further investigation. Our studies suggest that membrane damage and oxidative stress are the main routes of inhibition by SCFAs in E. coli. The outer membrane porin OmpF had the greatest impact on SCFA tolerance. Intracellular pH analysis on ompF mutants grown under octanoic acid stress indicated that this porin facilitates transport of SCFAs into the cell. The same response was observed under hexanoic acid stress, further supporting the role of OmpF in response to the presence of SCFAs. Furthermore, analysis of membrane protein expression revealed that other outer membrane porins are also involved in the response of E. coli to SCFAs. This work covers the first known proteomic analysis to assess the inhibitory effect of SCFAs in E. coli. SCFAs are molecules of great interest in the industry, but their microbial production is limited by their antimicrobial properties. This work allowed identification of differentially expressed proteins in response to SCFA stress and demonstrated the relevance of short- and medium-chain FA transport across the cell membrane via outer membrane porins, providing valuable insights on the toxicity mechanism of SCFAs in E. coli. These results could

Expanded flux variability analysis on metabolic network of Escherichia coli

Institute of Scientific and Technical Information of China (English)

CHEN Tong; XIE ZhengWei; OUYANG Qi

2009-01-01

Flux balance analysis,based on the mass conservation law in a cellular organism,has been extensively employed to study the interplay between structures and functions of cellular metabolic networks.Consequently,the phenotypes of the metabolism can be well elucidated.In this paper,we introduce the Expanded Flux Variability Analysis (EFVA) to characterize the intrinsic nature of metabolic reactions,such as flexibility,modularity and essentiality,by exploring the trend of the range,the maximum and the minimum flux of reactions.We took the metabolic network of Escherichia coli as an example and analyzed the variability of reaction fluxes under different growth rate constraints.The average variability of all reactions decreases dramatically when the growth rate increases.Consider the noise effect on the metabolic system,we thus argue that the microorganism may practically grow under a suboptimal state.Besides,under the EFVA framework,the reactions are easily to be grouped into catabolic and anabolic groups.And the anabolic groups can be further assigned to specific biomass constitute.We also discovered the growth rate dependent essentiality of reactions.

Structure-function analysis of the self-recognizing Antigen 43 autotransporter protein from Escherichia coli

DEFF Research Database (Denmark)

Klemm, Per; Hjerrild, L.; Gjermansen, Morten

2004-01-01

Antigen 43 (Ag43) is a self-recognizing surface adhesin found in most Escherichia coli strains. Expression of Ag43 confers aggregation and fluffing of cells, promotes biofilm formation and is associated with enhanced resistance to antimicrobial agents. Ag43 is an autotransporter protein and consi......Antigen 43 (Ag43) is a self-recognizing surface adhesin found in most Escherichia coli strains. Expression of Ag43 confers aggregation and fluffing of cells, promotes biofilm formation and is associated with enhanced resistance to antimicrobial agents. Ag43 is an autotransporter protein......-clumping variants, we have pinpointed the region of the protein responsible for autoaggregation to be located within the N-terminal one-third of the passenger domain. Our data suggest that ionic interactions between charged residues residing in interacting pairs of Ag43(alpha) domains may be important for the self...

Effect of high pressurized carbon dioxide on Escherichia coli ...

African Journals Online (AJOL)

Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high ...

Prevalence of Aeromonas species and Escherichia coli in stool ...

African Journals Online (AJOL)

Background: Diarrhoea is one of the main causes of mortality and morbidity in childhood. Bacterial diarrhoea is a common disorder. Aeromonas species and Escherichia coli (E. coli) are some of the aetiological agents associated with diarrhoea in children. Objective: To determine the prevalence of Aeromonas species and ...

Detection of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Market-Ready Chickens in Zambia.

Science.gov (United States)

Chishimba, K; Hang'ombe, B M; Muzandu, K; Mshana, S E; Matee, M I; Nakajima, C; Suzuki, Y

2016-01-01

The frequent administering of antibiotics in the treatment of poultry diseases may contribute to emergence of antimicrobial-resistant strains. The objective of this study was to detect the presence of extended-spectrum β-lactamase- (ESBL-) producing Escherichia coli in poultry in Zambia. A total of 384 poultry samples were collected and analyzed for ESBL-producing Escherichia coli. The cultured E. coli isolates were subjected to antimicrobial susceptibility tests and the polymerase chain reaction for detection of bla CTX-M, bla SHV, and bla TEM genes. Overall 20.1%, 77/384, (95% CI; 43.2-65.5%) of total samples analyzed contained ESBL-producing Escherichia coli. The antimicrobial sensitivity test revealed that 85.7% (66/77; CI: 75.7-92) of ESBL-producing E. coli isolates conferred resistance to beta-lactam and other antimicrobial agents. These results indicate that poultry is a potential reservoir for ESBL-producing Escherichia coli. The presence of ESBL-producing Escherichia coli in poultry destined for human consumption requires strengthening of the antibiotic administering policy. This is important as antibiotic administration in food animals is gaining momentum for improved animal productivity in developing countries such as Zambia.

Detection of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Market-Ready Chickens in Zambia

Directory of Open Access Journals (Sweden)

K. Chishimba

2016-01-01

Full Text Available The frequent administering of antibiotics in the treatment of poultry diseases may contribute to emergence of antimicrobial-resistant strains. The objective of this study was to detect the presence of extended-spectrum β-lactamase- (ESBL- producing Escherichia coli in poultry in Zambia. A total of 384 poultry samples were collected and analyzed for ESBL-producing Escherichia coli. The cultured E. coli isolates were subjected to antimicrobial susceptibility tests and the polymerase chain reaction for detection of blaCTX-M, blaSHV, and blaTEM genes. Overall 20.1%, 77/384, (95% CI; 43.2–65.5% of total samples analyzed contained ESBL-producing Escherichia coli. The antimicrobial sensitivity test revealed that 85.7% (66/77; CI: 75.7–92 of ESBL-producing E. coli isolates conferred resistance to beta-lactam and other antimicrobial agents. These results indicate that poultry is a potential reservoir for ESBL-producing Escherichia coli. The presence of ESBL-producing Escherichia coli in poultry destined for human consumption requires strengthening of the antibiotic administering policy. This is important as antibiotic administration in food animals is gaining momentum for improved animal productivity in developing countries such as Zambia.

Genomic Comparative Study of Bovine Mastitis Escherichia coli.

Science.gov (United States)

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.

An evolutionary analysis of genome expansion and pathogenicity in Escherichia coli

OpenAIRE

Bohlin, Jon; Brynildsrud, Ola B; Sekse, Camilla; Snipen, Lars

2014-01-01

Background There are several studies describing loss of genes through reductive evolution in microbes, but how selective forces are associated with genome expansion due to horizontal gene transfer (HGT) has not received similar attention. The aim of this study was therefore to examine how selective pressures influence genome expansion in 53 fully sequenced and assembled Escherichia coli strains. We also explored potential connections between genome expansion and the attainment of virulence fa...

Quantitative analysis of relationships between fluxome and metabolome in Escherichia coli

OpenAIRE

Taymaz Nikerel, H.

2010-01-01

Kinetic models, which predict the behaviour of metabolic reaction networks under different conditions, are indispensible to fully and quantitatively understand the relation between a product pathway and connected central metabolism. In this thesis the focus was to develop tools for future in vivo kinetic modeling in Escherichia coli. The relations between fluxome and metabolome at steady-state or transient state but where enzyme levels can be assumed constant are investigated. In addition, we...

Insights into the evolution of pathogenicity of Escherichia coli from genomic analysis of intestinal E. coli of Marmota himalayana in Qinghai-Tibet plateau of China.

Science.gov (United States)

Lu, Shan; Jin, Dong; Wu, Shusheng; Yang, Jing; Lan, Ruiting; Bai, Xiangning; Liu, Sha; Meng, Qiong; Yuan, Xuejiao; Zhou, Juan; Pu, Ji; Chen, Qiang; Dai, Hang; Hu, Yuanyuan; Xiong, Yanwen; Ye, Changyun; Xu, Jianguo

2016-12-07

Escherichia coli is both of a widespread harmless gut commensal and a versatile pathogen of humans. Domestic animals are a well-known reservoir for pathogenic E. coli. However, studies of E. coli populations from wild animals that have been separated from human activities had been very limited. Here we obtained 580 isolates from intestinal contents of 116 wild Marmot Marmota himalayana from Qinghai-Tibet plateau, China, with five isolates per animal. We selected 125 (hereinafter referred to as strains) from the 580 isolates for genome sequencing, based on unique pulse field gel electrophoresis patterns and at least one isolate per animal. Whole genome sequence analysis revealed that all 125 strains carried at least one and the majority (79.2%) carried multiple virulence genes based on the analysis of 22 selected virulence genes. In particular, the majority of the strains carried virulence genes from different pathovars as potential 'hybrid pathogens'. The alleles of eight virulence genes from the Marmot E. coli were found to have diverged earlier than all known alleles from human and other animal E. coli. Phylogenetic analysis of the 125 Marmot E. coli genomes and 355 genomes selected from 1622 human and other E. coli strains identified two new phylogroups, G and H, both of which diverged earlier than the other phylogroups. Eight of the 12 well-known pathogenic E. coli lineages were found to share a most recent common ancestor with one or more Marmot E. coli strains. Our results suggested that the intestinal E. coli of the Marmots contained a diverse virulence gene pool and is potentially pathogenic to humans. These findings provided a new understanding of the evolutionary origin of pathogenic E. coli.

Synergistic effects in mixed Escherichia coli biofilms

DEFF Research Database (Denmark)

Reisner, A.; Holler, B.M.; Molin, Søren

2006-01-01

Bacterial biofilms, often composed of multiple species and genetically distinct strains, develop under complex influences of cell-cell interactions. Although detailed knowledge about the mechanisms underlying formation of single-species laboratory biofilms has emerged, little is known about...... the pathways governing development of more complex heterogeneous communities. In this study, we established a laboratory model where biofilm-stimulating effects due to interactions between genetically diverse strains of Escherichia coli were monitored. Synergistic induction of biofilm formation resulting from...... the cocultivation of 403 undomesticated E. coli strains with a characterized E. coli K-12 strain was detected at a significant frequency. The survey suggests that different mechanisms underlie the observed stimulation, yet synergistic development of biofilm within the subset of E. coli isolates (n = 56) exhibiting...

Multiple-Resistant Commensal Escherichia Coli from Nigerian ...

African Journals Online (AJOL)

Purpose: The antimicrobial susceptibility and virulence traits of 150 strains of Escherichia coli ... and ethical approval was obtained from the Health .... persist in the guts by virtue of the ability of such ... cases of diarrhoea in Ile-Ife and environs.

Synthesis and processing of escherichia-coli tem-beta-lactamase and bacillus-licheniformis alpha-amylase in escherichia-coli : The role of signal peptidase-i

NARCIS (Netherlands)

van Dijl, J M; Smith, H; Bron, Sierd; Venema, Gerard

A mutant of Escherichia coli, in which signal peptidase I synthesis can be regulated, was constructed. The mutant was used to study the effects of signal peptidase I limitation on the synthesis and efficiency of processing of two proteins: the periplasmic E. coli TEM-beta-lactamase and Bacillus

SYNTHESIS AND PROCESSING OF ESCHERICHIA-COLI TEM-BETA-LACTAMASE AND BACILLUS-LICHENIFORMIS ALPHA-AMYLASE IN ESCHERICHIA-COLI : THE ROLE OF SIGNAL PEPTIDASE-I

NARCIS (Netherlands)

van Dijl, J M; SMITH, H; BRON, S; VENEMA, G

A mutant of Escherichia coli, in which signal peptidase I synthesis can be regulated, was constructed. The mutant was used to study the effects of signal peptidase I limitation on the synthesis and efficiency of processing of two proteins: the periplasmic E. coli TEM-beta-lactamase and Bacillus

Changes in Escherichia coli resistance to co-trimoxazole in ...

African Journals Online (AJOL)

In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out to determine i) whether faecal Escherichia coli (E.coli) resistance to ...

Autodisplay of an avidin with biotin-binding activity on the surface of Escherichia coli.

Science.gov (United States)

Pardavé-Alejandre, H D; Alvarado-Yaah, J E; Pompa-Mera, E N; Muñoz-Medina, J E; Sárquiz-Martínez, B; Santacruz-Tinoco, C E; Manning-Cela, R G; Ortíz-Navarrete, V; López-Macías, C; González-Bonilla, C R

2018-03-01

To display a recombinant avidin fused to the autotransporter ShdA to bind biotinylated molecules on the surface of Escherichia coli. Two chimeric protein constructs containing avidin fused to the autotransporter ShdA were expressed on the surface of Escherichia coli DH5α. One fusion protein contained 476 amino acids of the ShdA α and β domains, whereas the second consisted of a 314 amino acid from α and truncated β domains. Protein production was verified by SDS-PAGE using an antibody to the molecular FLAG-tag. The surface display of the avidin-shdA fusion protein was confirmed by confocal microscopy and flow cytometry analysis, and the biotin-binding activity was evaluated by fluorescence microscopy and flow cytometry using biotin-4-fluorescein and biotinylated-ovalbumin (OVA). Expression of a recombinant avidin with biotin-binding activity on the surface of E. coli was achieved using the autotransporter ShdA. This system is an alternative to bind biotinylated molecules to E. coli.

Isolation and genomic characterization of Escherichia coli O157:NM ...

African Journals Online (AJOL)

Human diseases caused by Escherichia coli O157:NM and E. coli O157:H7 strains have been reported throughout the world. In developed countries, serotype O157:H7 represents the major cause of human diseases; however, there have been increasing reports of non-O157 Shiga toxin (Stx)-producing E. coli strains ...

Escherichia coli. A sanitary methodology for faecal water pollution tests; Escherichia coli nelle acque. Significato sanitario e metodologie di analisi

Energy Technology Data Exchange (ETDEWEB)

Bonadonna, L. [Istituto Superiore di Sanita' , Rome (Italy)

2001-02-01

Among the traditional indictors of faecal water pollution, Escherichia coli has shown to fit better with the definition of indicator organism. Till now its recovery has been time-consuming and needs confirmation tests. In this report more rapid and direct methods, based on enzymatic reactions, are presented. [Italian] Per talune peculiari caratteristiche, Escherichia coli sembra meglio soddisfare i requisiti insiti nella definizione di organismo indicatore, rispetto ai tradizionali indicatori di contaminazione fecale dell'acqua. Finora, i substrati disponibili per il suo rilevamento necessitano tutti di almeno una prova di conferma. Di qui l'esigenza di indicare metodi di rilevamento a riposta piu' rapida, anche in relazione all'inserimento, nelle piu' recenti normative nazionali ed europee, del microrganismo tra i parametri microbiologici da ricercare.

Predictors Of Non-Escherichia Coli Urinary Tract Infection.

Science.gov (United States)

Shaikh, Nader; Wald, Ellen R; Keren, Ron; Gotman, Nathan; Ivanova, Anastasia; Carpenter, Myra A; Moxey-Mims, Marva; Hoberman, Alejandro

2016-11-01

We aimed to determine which children are prone to non-Escherichia coli urinary tract infection (UTIs). We included 769 children with UTI. We found that circumcised males, Hispanic children, children without fever and children with grades 3 and 4 vesicoureteral reflux were more likely to have a UTI caused by organisms other than E. coli. This information may guide clinicians in their choice of antimicrobial therapy.

Engineering Escherichia coli for methanol conversion.

Science.gov (United States)

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. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Vaginal Lactobacillus isolates inhibit uropathogenic Escherichia coli.

OpenAIRE

Atassi , Fabrice; Brassart , Dominique; Grob , Philipp; Graf , Federico; Servin , Alain ,

2006-01-01

The purpose of this study was to investigate the antibacterial activities of Lactobacillus jensenii KS119.1 and KS121.1, and Lactobacillus gasserii KS120.1 and KS124.3 strains isolated from the vaginal microflora of healthy women, against uropathogenic, diffusely adhering Afa/Dr Escherichia coli (Afa/Dr DAEC) strains IH11128 and 7372 involved in recurrent cystitis. We observed that some of the Lactobacillus isolates inhibited the growth and decreased the viability of E. coli IH11128 and 7372....

Efficient Extracellular Expression of Phospholipase D in Escherichia Coli with an Optimized Signal Peptide

Science.gov (United States)

Yang, Leyun; Xu, Yu; Chen, Yong; Ying, Hanjie

2018-01-01

New secretion vectors containing the synthetic signal sequence (OmpA’) was constructed for the secretory production of recombinant proteins in Escherichia coli. The E. coli Phospholipase D structural gene (Accession number:NC_018658) fused to various signal sequence were expressed from the Lac promoter in E. coli Rosetta strains by induction with 0.4mM IPTG at 28°C for 48h. SDS-PaGe analysis of expression and subcellular fractions of recombinant constructs revealed the translocation of Phospholipase D (PLD) not only to the medium but also remained in periplasm of E. coli with OmpA’ signal sequence at the N-terminus of PLD. Thus the study on the effects of various surfactants on PLD extracellular production in Escherichia coli in shake flasks revealed that optimal PLD extracellular production could be achieved by adding 0.4% Triton X-100 into the medium. The maximal extracellular PLD production and extracellular enzyme activity were 0.23mg ml-1 and 16U ml-1, respectively. These results demonstrate the possibility of efficient secretory production of recombinant PLD in E. coli should be a potential industrial applications.

Class 1 integrons in ciprofloxacin-resistant Escherichia coli strains from two Dutch hospitals

NARCIS (Netherlands)

Mooij, M. J.; Schouten, I.; Vos, G.; van Belkum, A.; Vandenbroucke-Grauls, C. M. J. E.; Savelkoul, P. H. M.; Schultsz, C.

2005-01-01

A significant increase in the isolation frequency of ciprofloxacin-resistant Escherichia coli was observed in the haematology departments of two university hospitals in The Netherlands. Amplified fragment length polymorphism analysis revealed that this increase was not caused by the emergence of

Global identification of prokaryotic glycoproteins based on an Escherichia coli proteome microarray.

Directory of Open Access Journals (Sweden)

Zong-Xiu Wang

Full Text Available Glycosylation is one of the most abundant protein posttranslational modifications. Protein glycosylation plays important roles not only in eukaryotes but also in prokaryotes. To further understand the roles of protein glycosylation in prokaryotes, we developed a lectin binding assay to screen glycoproteins on an Escherichia coli proteome microarray containing 4,256 affinity-purified E.coli proteins. Twenty-three E.coli proteins that bound Wheat-Germ Agglutinin (WGA were identified. PANTHER protein classification analysis showed that these glycoprotein candidates were highly enriched in metabolic process and catalytic activity classes. One sub-network centered on deoxyribonuclease I (sbcB was identified. Bioinformatics analysis suggests that prokaryotic protein glycosylation may play roles in nucleotide and nucleic acid metabolism. Fifteen of the 23 glycoprotein candidates were validated by lectin (WGA staining, thereby increasing the number of validated E. coli glycoproteins from 3 to 18. By cataloguing glycoproteins in E.coli, our study greatly extends our understanding of protein glycosylation in prokaryotes.

Growth modeling of uropathogenic Escherichia coli in ground chicken meat

Science.gov (United States)

Extraintestinal Pathogenic Escherichia coli (ExPEC), including Uropathogenic E. coli (UPEC), are common contaminants in poultry meat, and are a major pathogen associated with inflammatory bowel disease, ulcerative colitis, sepsis, and urinary tract infections. The purpose of this study was to determ...

Gene Expression Analysis of Escherichia Coli Grown in Miniaturized Bioreactor Platforms for High-Throughput Analysis of Growth and genomic Data

DEFF Research Database (Denmark)

Boccazzi, P.; Zanzotto, A.; Szita, Nicolas

2005-01-01

Combining high-throughput growth physiology and global gene expression data analysis is of significant value for integrating metabolism and genomics. We compared global gene expression using 500 ng of total RNA from Escherichia coli cultures grown in rich or defined minimal media in a miniaturize...... cultures using just 500 ng of total RNA indicate that high-throughput integration of growth physiology and genomics will be possible with novel biochemical platforms and improved detection technologies....

Three-decade epidemiological analysis of Escherichia coli O15:K52:H1

DEFF Research Database (Denmark)

Olesen, Bente; Scheutz, Flemming; Menard, Megan

2009-01-01

The successful Escherichia coli O15:K52:H1 clonal group provides a case study for the emergence of multiresistant clonal groups of Enterobacteriaceae generally. Accordingly, we tested the hypotheses that, over time, the O15:K52:H1 clonal group has become increasingly (i) virulent and (ii) resistant...... to antibiotics. One hundred archived international E. coli O15:K52:[H1] clinical isolates from 100 unique patients (1975 to 2006) were characterized for diverse phenotypic and molecular traits. All 100 isolates derived from phylogenetic group D and, presumptively, sequence type ST393. They uniformly carried...

(ESBL) producing Escherichia coli and Klebsiella pneumoniae

African Journals Online (AJOL)

Emerging antibiotic resistance due to extended spectrum β-lactamase (ESBL) production limited the use of β-lactam antibiotics against Escherichia coli and Klebsiella pneumoniae. This observational study was conducted at the Microbiology department of the Children's Hospital, Lahore Pakistan, from June, 2009 to ...

Antibiotic resistance properties of uropathogenic Escherichia coli ...

African Journals Online (AJOL)

Purpose: To investigate the antibiotic resistance pattern of uropathogenic Escherichia coli (UPEC) strains isolated from pregnant women with history of recurrent urinary tract infections (RUTIs) and healthy pregnant women. Methods: A total of 485 high vaginal swab specimens were collected from pregnant women with ...

Enhancement of L-cysteine production by disruption of yciW in Escherichia coli.

Science.gov (United States)

Kawano, Yusuke; Ohtsu, Iwao; Takumi, Kazuhiro; Tamakoshi, Ai; Nonaka, Gen; Funahashi, Eri; Ihara, Masaki; Takagi, Hiroshi

2015-02-01

Using in silico analysis, the yciW gene of Escherichia coli was identified as a novel L-cysteine regulon that may be regulated by the transcriptional activator CysB for sulfur metabolic genes. We found that overexpression of yciW conferred tolerance to L-cysteine, but disruption of yciW increased L-cysteine production in E. coli. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Diarrheagenic Escherichia coli and acute and persistent diarrhea in returned travelers

NARCIS (Netherlands)

Schultsz, C.; van den Ende, J.; Cobelens, F.; Vervoort, T.; van Gompel, A.; Wetsteyn, J. C.; Dankert, J.

2000-01-01

To determine the role of diarrheagenic Escherichia coli in acute and persistent diarrhea in returned travelers, a case control study was performed. Enterotoxigenic E. coli (ETEC) was detected in stool samples from 18 (10.7%) of 169 patients and 4 (3.7%) of 108 controls. Enteroaggregative E. coli

An evolutionary analysis of genome expansion and pathogenicity in Escherichia coli.

Science.gov (United States)

Bohlin, Jon; Brynildsrud, Ola B; Sekse, Camilla; Snipen, Lars

2014-10-09

There are several studies describing loss of genes through reductive evolution in microbes, but how selective forces are associated with genome expansion due to horizontal gene transfer (HGT) has not received similar attention. The aim of this study was therefore to examine how selective pressures influence genome expansion in 53 fully sequenced and assembled Escherichia coli strains. We also explored potential connections between genome expansion and the attainment of virulence factors. This was performed using estimations of several genomic parameters such as AT content, genomic drift (measured using relative entropy), genome size and estimated HGT size, which were subsequently compared to analogous parameters computed from the core genome consisting of 1729 genes common to the 53 E. coli strains. Moreover, we analyzed how selective pressures (quantified using relative entropy and dN/dS), acting on the E. coli core genome, influenced lineage and phylogroup formation. Hierarchical clustering of dS and dN estimations from the E. coli core genome resulted in phylogenetic trees with topologies in agreement with known E. coli taxonomy and phylogroups. High values of dS, compared to dN, indicate that the E. coli core genome has been subjected to substantial purifying selection over time; significantly more than the non-core part of the genome (pcoli genome size correlated with estimated HGT size (pcoli are largely attained through HGT. No associations were found between selective pressures operating on the E. coli core genome, as estimated using relative entropy, and genome size (p~0.98). On a larger time frame, genome expansion in E. coli, which is significantly associated with the acquisition of virulence factors, appears to be independent of selective forces operating on the core genome.

Primary and secondary cases in Escherichia coli O157 outbreaks: a statistical analysis.

LENUS (Irish Health Repository)

Snedeker, Kate G

2009-01-01

BACKGROUND: Within outbreaks of Escherichia coli O157 (E. coli O157), at least 10-15% of cases are thought to have been acquired by secondary transmission. However, there has been little systematic quantification or characterisation of secondary outbreak cases worldwide. The aim of this study was to characterise secondary outbreak cases, estimate the overall proportion of outbreak cases that were the result of secondary transmission and to analyse the relationships between primary and secondary outbreak cases by mode of transmission, country and median age. METHODS: Published data was obtained from 90 confirmed Escherichia coli O157 outbreaks in Great Britain, Ireland, Scandinavia, Canada, the United States and Japan, and the outbreaks were described in terms of modes of primary and secondary transmission, country, case numbers and median case age. Outbreaks were tested for statistically significant differences in the number of ill, confirmed, primary and secondary cases (analysis of variance and Kruskal-Wallis) and in the rate of secondary cases between these variables (Generalised Linear Models). RESULTS: The outbreaks had a median of 13.5 confirmed cases, and mean proportion of 0.195 secondary cases. There were statistically significant differences in the numbers of ill, confirmed, primary and secondary cases between modes of primary transmission (p < 0.021), and in primary and secondary cases between median age categories (p < 0.039) and modes of secondary transmission (p < 0.001).Secondary case rates differed statistically significantly between modes of secondary and primary transmission and median age categories (all p < 0.001), but not between countries (p = 0.23). Statistically significantly higher rates of secondary transmission were found in outbreaks with a median age <6 years and those with secondary transmission via person to person spread in nurseries. No statistically significant interactions were found between country, mode of transmission and age

Hydrogen production by recombinant Escherichia coli strains

Science.gov (United States)

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

Prevalence of Antibiotic Resistance in Escherichia coli Isolated from Poultry Meat Supply in Isfahan

Directory of Open Access Journals (Sweden)

Farhad Safarpordehkordi

2014-08-01

Conclusions: Despite the high contamination rate of chicken meat with Escherichia coli, majority of isolates had high resistance to common antibiotics. Complete cooking of meat and avoid indiscriminate prescribing of antibiotics, preventing the occurrence of food poisoning due to resistant Escherichia coli.

Difference in melting profiles of gamma irradiated DNA from chicken erythrocytes and from Escherichia coli B/r

International Nuclear Information System (INIS)

Kopff, J.; Miller, G.; Leyko, W.

1977-01-01

Effects of gamma irradiation on melting curves of DNA from chicken erythrocytes and Escherichia coli B/r were compared. Considerable changes, following gamma irradiation in the case of chicken erythrocytes DNA and no changes in the case of DNA from Escherichia coli B/r were observed. To explain the lack of changes in gamma irradiated samples of DNA from Escherichia coli B/r it was assumed that the original effects of irradiation were obscured by the process of renaturation of DNA. To exclude the above mentioned effect, examination of gamma irradiated DNA from Escherichia coli B/r was carried out with the addition of formaldehyde immediately after irradiation of the sample. Using this procedure changes of melting profiles of DNA from Escherichia coli B/r were demonstrated. (author)

Detecção de fatores de virulência de Escherichia coli e análise de Salmonella spp. em psitacídeos Detection of virulence factors in Escherichia coli and analysis of Salmonella spp. in psittacines

Directory of Open Access Journals (Sweden)

Isadora M. de O. Corrêa

2013-02-01

Full Text Available A flora entérica dos psitacídeos é composta principalmente por bactérias Gram positivas. Bactérias Gram negativas, como Escherichia coli e Salmonella spp., apresentam elevado potencial patogênico, sendo consideradas indicativo de problemas de manejo, que poderão culminar em manifestação de doenças em decorrência de fatores estressantes, dietas deficientes e superlotação, combinados com alta carga bacteriana no ambiente. O objetivo deste trabalho foi avaliar a presença de Salmonella spp., Escherichia coli e os fatores de virulência dos genes iss e iutA dos isolados de E. coli. Analisou-se um total de 44 amostras provenientes de psitacídeos criados em cativeiro, sendo estas 15 fragmentos de órgãos de aves submetidas a exame de necropsia e também 29 amostras de swabs de cloaca e inglúvio de papagaios-charão (Amazona pretrei criados em cativeiro. Nenhuma amostra foi positiva para Salmonella spp. Nas amostras de E. coli detectou-se ambos os fatores de virulência pesquisados.The enteric flora of psittacines is mainly composed of Gram positive bacteria. Gram negative bacteria, like Escherichia coli and Salmonella spp., have a high pathogenic potential and can be considerate as an indicative of management problems that may culminate in disease manifestation due to stress factors, poor diets and overcrowding, in combination with a high bacterial load on the environment. The objective of this study was evaluated the presence of Salmonella spp., Escherichia coli and the virulence genes iss and iutA from E. coli isolates. Forty-four samples were analyzed from psittacines living in captivity, which fifteen samples were from organs fragments of necropsied birds, and twenty-nine were from cloacal and crop swabs of red-spectacled parrots (Amazona pretrei keeping in captivity. No samples were positive for Salmonella spp. In the samples in which E. coli was detected, both virulence factors (genes iss and iutA were present.

Expression of green fluorescent protein (GFPuv) in Escherichia coli ...

African Journals Online (AJOL)

Administrator

The recombinant green fluorescent protein (GFPuv) was expressed by transformed cells of Escherichia coli DH5-α grown in LB/amp broth at 37oC, for 8 h and 24 h. To evaluate the effectiveness of different parameters to improve the expression of GFPuv by E. coli, four variable culturing conditions were set up for assays by ...

Optimization of plasmid electrotransformation into Escherichia coli ...

African Journals Online (AJOL)

In order to improve electroporation, optical density of bacteria, recovery time and electrical parameter (field strength and capacitance) were optimized using the Taguchi statistical method. ANOVA of obtained data indicated that the optimal conditions of electrotransformation of pET-28a (+) plasmid into Escherichia coli ...

Comparative genomics and transcriptomics of Escherichia coli isolates carrying virulence factors of both enteropathogenic and enterotoxigenic E. coli.

Science.gov (United States)

Hazen, Tracy H; Michalski, Jane; Luo, Qingwei; Shetty, Amol C; Daugherty, Sean C; Fleckenstein, James M; Rasko, David A

2017-06-14

Escherichia coli that are capable of causing human disease are often classified into pathogenic variants (pathovars) based on their virulence gene content. However, disease-associated hybrid E. coli, containing unique combinations of multiple canonical virulence factors have also been described. Such was the case of the E. coli O104:H4 outbreak in 2011, which caused significant morbidity and mortality. Among the pathovars of diarrheagenic E. coli that cause significant human disease are the enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC). In the current study we use comparative genomics, transcriptomics, and functional studies to characterize isolates that contain virulence factors of both EPEC and ETEC. Based on phylogenomic analysis, these hybrid isolates are more genomically-related to EPEC, but appear to have acquired ETEC virulence genes. Global transcriptional analysis using RNA sequencing, demonstrated that the EPEC and ETEC virulence genes of these hybrid isolates were differentially-expressed under virulence-inducing laboratory conditions, similar to reference isolates. Immunoblot assays further verified that the virulence gene products were produced and that the T3SS effector EspB of EPEC, and heat-labile toxin of ETEC were secreted. These findings document the existence and virulence potential of an E. coli pathovar hybrid that blurs the distinction between E. coli pathovars.

Hemolytic Porcine Intestinal Escherichia coli without Virulence-Associated Genes Typical of Intestinal Pathogenic E. coli ▿ †

Science.gov (United States)

Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

2011-01-01

Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli. PMID:21965399

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

Science.gov (United States)

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.

Identifying New Small Proteins in Escherichia coli.

Science.gov (United States)

VanOrsdel, Caitlin E; Kelly, John P; Burke, Brittany N; Lein, Christina D; Oufiero, Christopher E; Sanchez, Joseph F; Wimmers, Larry E; Hearn, David J; Abuikhdair, Fatimeh J; Barnhart, Kathryn R; Duley, Michelle L; Ernst, Sarah E G; Kenerson, Briana A; Serafin, Aubrey J; Hemm, Matthew R

2018-04-12

The number of small proteins (SPs) encoded in the Escherichia coli genome is unknown, as current bioinformatics and biochemical techniques make short gene and small protein identification challenging. One method of small protein identification involves adding an epitope tag to the 3' end of a short open reading frame (sORF) on the chromosome, with synthesis confirmed by immunoblot assays. In this study, this strategy was used to identify new E. coli small proteins, tagging 80 sORFs in the E. coli genome, and assayed for protein synthesis. The selected sORFs represent diverse sequence characteristics, including degrees of sORF conservation, predicted transmembrane domains, sORF direction with respect to flanking genes, ribosome binding site (RBS) prediction, and ribosome profiling results. Of 80 sORFs, 36 resulted in encoded synthesized proteins-a 45% success rate. Modeling of detected versus non-detected small proteins analysis showed predictions based on RBS prediction, transcription data, and ribosome profiling had statistically-significant correlation with protein synthesis; however, there was no correlation between current sORF annotation and protein synthesis. These results suggest substantial numbers of small proteins remain undiscovered in E. coli, and existing bioinformatics techniques must continue to improve to facilitate identification. © 2018 The Authors. Proteomics Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Towson University.

Quantitative analysis of commensal Escherichia coli populations reveals host-specific enterotypes at the intra-species level

OpenAIRE

Smati, Mounira; Clermont, Olivier; Bleibtreu, Alexandre; Fourreau, Frédéric; David, Anthony; Daubié, Anne-Sophie; Hignard, Cécile; Loison, Odile; Picard, Bertrand; Denamur, Erick

2015-01-01

The primary habitat of the Escherichia coli species is the gut of warm-blooded vertebrates. The E. coli species is structured into four main phylogenetic groups A, B1, B2, and D. We estimated the relative proportions of these phylogroups in the feces of 137 wild and domesticated animals with various diets living in the Ile de France (Paris) region by real-time PCR. We distinguished three main clusters characterized by a particular abundance of two or more phylogroups within the E. coli animal...

Postgenomics Characterization of an Essential Genetic Determinant of Mammary Pathogenic Escherichia coli.

Science.gov (United States)

Blum, Shlomo E; Goldstone, Robert J; Connolly, James P R; Répérant-Ferter, Maryline; Germon, Pierre; Inglis, Neil F; Krifucks, Oleg; Mathur, Shubham; Manson, Erin; Mclean, Kevin; Rainard, Pascal; Roe, Andrew J; Leitner, Gabriel; Smith, David G E

2018-04-03

Escherichia coli are major bacterial pathogens causing bovine mastitis, a disease of great economic impact on dairy production worldwide. This work aimed to study the virulence determinants of mammary pathogenic E. coli (MPEC). By whole-genome sequencing analysis of 40 MPEC and 22 environmental ("dairy-farm" E. coli [DFEC]) strains, we found that only the fec locus ( fecIRABCDE ) for ferric dicitrate uptake was present in the core genome of MPEC and that it was absent in DFEC genomes ( P price of dairy products on supermarket shelves and the financial hardships suffered by dairy farmers. Mastitis is also the leading reason for the use of antibiotics in dairy farms. Good farm management practices in many countries have dramatically reduced the incidence of contagious mastitis; however, the problems associated with the incidence of environmental mastitis caused by bacteria such as Escherichia coli have proven intractable. E. coli bacteria cause acute mastitis, which affects the health and welfare of cows and in extreme cases may be fatal. Here we show for the first time that the pathogenicity of E. coli causing mastitis in cows is highly dependent on the fecIRABCDE ferric citrate uptake system that allows the bacterium to capture iron from citrate. The Fec system is highly expressed during infection in the bovine udder and is ubiquitous in and necessary for the E. coli bacteria that cause mammary infections in cattle. These results have far-reaching implications, raising the possibility that mastitis may be controllable by targeting this system. Copyright © 2018 Blum et al.

Hydrogen production and metabolic flux analysis of metabolically engineered Escherichia coli strains

Energy Technology Data Exchange (ETDEWEB)

Kim, Seohyoung; Seol, Eunhee; Park, Sunghoon [Department of Chemical and Biochemical Engineering, Pusan National University, Busan 609-735 (Korea); Oh, You-Kwan [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-543 (Korea); Wang, G.Y. [Department of Oceanography, University of Hawaii at Manoa Honolulu, HI 96822 (United States)

2009-09-15

Escherichia coli can produce H{sub 2} from glucose via formate hydrogen lyase (FHL). In order to improve the H{sub 2} production rate and yield, metabolically engineered E. coli strains, which included pathway alterations in their H{sub 2} production and central carbon metabolism, were developed and characterized by batch experiments and metabolic flux analysis. Deletion of hycA, a negative regulator for FHL, resulted in twofold increase of FHL activity. Deletion of two uptake hydrogenases (1 (hya) and hydrogenase 2 (hyb)) increased H{sub 2} production yield from 1.20 mol/mol glucose to 1.48 mol/mol glucose. Deletion of lactate dehydrogenase (ldhA) and fumarate reductase (frdAB) further improved the H{sub 2} yield; 1.80 mol/mol glucose under high H{sub 2} pressure or 2.11 mol/mol glucose under reduced H{sub 2} pressure. Several batch experiments at varying concentrations of glucose (2.5-10 g/L) and yeast extract (0.3 or 3.0 g/L) were conducted for the strain containing all these genetic alternations, and their carbon and energy balances were analyzed. The metabolic flux analysis revealed that deletion of ldhA and frdAB directed most of the carbons from glucose to the glycolytic pathway leading to H{sub 2} production by FHL, not to the pentose phosphate pathway. (author)

Analysis of whole genome sequencing for the Escherichia coli O157:H7 typing phages.

Science.gov (United States)

Cowley, Lauren A; Beckett, Stephen J; Chase-Topping, Margo; Perry, Neil; Dallman, Tim J; Gally, David L; Jenkins, Claire

2015-04-08

Shiga toxin producing Escherichia coli O157 can cause severe bloody diarrhea and haemolytic uraemic syndrome. Phage typing of E. coli O157 facilitates public health surveillance and outbreak investigations, certain phage types are more likely to occupy specific niches and are associated with specific age groups and disease severity. The aim of this study was to analyse the genome sequences of 16 (fourteen T4 and two T7) E. coli O157 typing phages and to determine the genes responsible for the subtle differences in phage type profiles. The typing phages were sequenced using paired-end Illumina sequencing at The Genome Analysis Centre and the Animal Health and Veterinary Laboratories Agency and bioinformatics programs including Velvet, Brig and Easyfig were used to analyse them. A two-way Euclidian cluster analysis highlighted the associations between groups of phage types and typing phages. The analysis showed that the T7 typing phages (9 and 10) differed by only three genes and that the T4 typing phages formed three distinct groups of similar genomic sequences: Group 1 (1, 8, 11, 12 and 15, 16), Group 2 (3, 6, 7 and 13) and Group 3 (2, 4, 5 and 14). The E. coli O157 phage typing scheme exhibited a significantly modular network linked to the genetic similarity of each group showing that these groups are specialised to infect a subset of phage types. Sequencing the typing phage has enabled us to identify the variable genes within each group and to determine how this corresponds to changes in phage type.

FimH-mediated autoaggregation of Escherichia coli

DEFF Research Database (Denmark)

Schembri, Mark; Christiansen, G.; Klemm, Per

2001-01-01

Autoaggregation is a phenomenon thought to contribute to colonization of mammalian hosts by pathogenic bacteria. Type 1 fimbriae are surface organelles of Escherichia coli that mediate D-mannose-sensitive binding to various host surfaces. This binding is conferred by the minor fimbrial component...... FimH. In this study, we have used random mutagenesis to identify variants of the FimH adhesin that confer the ability of E. coli to autoaggregate and settle from liquid cultures. Three separate autoaggregating clones were identified, all of which contained multiple amino acid changes located within...

Inhibition of Escherichia Coli, Salmonella and Staphylococcus ...

African Journals Online (AJOL)

Escherichia coli O157:H7, Salmonella typhimurium and Staphylococcus. aureus are of great concern to the food industry, especially in foods stored under refrigerated conditions where, unlike most food-borne pathogens are able to multiply. This investigation was conducted to study the inhibitory effect of some spice ...

Prevalence of Arcobacter, Escherichia coli, Staphylococcus aureus ...

African Journals Online (AJOL)

In this study, varying level of resistance of Escherichia coli 66(84.6%), Salmonella 6(100%) and Arcobacter 57(100%) to amoxicillin was observed. The susceptibility pattern indicates that the bacterial isolates exhibited a varying level of resistance to two or more antimicrobial agents with maximum resistance to amoxicillin.

Leaner and meaner genomes in Escherichia coli

DEFF Research Database (Denmark)

Ussery, David

2006-01-01

A 'better' Escherichia coli K-12 genome has recently been engineered in which about 15% of the genome has been removed by planned deletions. Comparison with related bacterial genomes that have undergone a natural reduction in size suggests that there is plenty of scope for yet more deletions....

Profiling of Escherichia coli Chromosome database.

Science.gov (United States)

Yamazaki, Yukiko; Niki, Hironori; Kato, Jun-ichi

2008-01-01

The Profiling of Escherichia coli Chromosome (PEC) database (http://www.shigen.nig.ac.jp/ecoli/pec/) is designed to allow E. coli researchers to efficiently access information from functional genomics studies. The database contains two principal types of data: gene essentiality and a large collection of E. coli genetic research resources. The essentiality data are based on data compilation from published single-gene essentiality studies and on cell growth studies of large-deletion mutants. Using the circular and linear viewers for both whole genomes and the minimal genome, users can not only gain an overview of the genome structure but also retrieve information on contigs, gene products, mutants, deletions, and so forth. In particular, genome-wide exhaustive mutants are an essential resource for studying E. coli gene functions. Although the genomic database was constructed independently from the genetic resources database, users may seamlessly access both types of data. In addition to these data, the PEC database also provides a summary of homologous genes of other bacterial genomes and of protein structure information, with a comprehensive interface. The PEC is thus a convenient and useful platform for contemporary E. coli researchers.

Adsorption of Escherichia coli Using Bone Char | Rezaee | Journal ...

African Journals Online (AJOL)

The aim of study was providing a novel adsorbent for the removal of Escherichia coli (E.coli) as a microbial model from contaminated air especially in hospital units using bone char (BC). The BC was prepared from cattle animal bone by pyrolysis in a furnace at 450°C for 2 h. The characteristics of BC have been determined ...

Escherichia coli photoreactivating enzyme: purification and properties

International Nuclear Information System (INIS)

Snapka, R.M.; Sutherland, B.M.

1980-01-01

Researchers have purified large quantities of Escherichia coli photoreactivating enzyme to apparent homogeneity and have studied its physical and chemical properties. The enzyme has a molecular weight of 36,800 and a S/sub 20,w/ 0 of 3.72 S. Amino acid analysis revealed an apparent absence of tryptophan, a low content of aromatic residues, and the presence of no unusual amino acids. The N terminus is arginine. The purified enzyme contained up to 13% carbohydrate by weight. The carbohydrate was composed of mannose, galactose, glucose, and N-acetylglucosamine. The enzyme is also associated with RNA containing uracil, adenine, guanine, and cytosine with no unusual bases detected

Crystal structure and mechanism of the lytic transglycosylase MltA from Escherichia coli

NARCIS (Netherlands)

van Straaten, Karin

2006-01-01

This thesis describes the determination and analysis of the 3D-structure of the lytic transglycosylase MltA from Escherichia coli by X-ray crystallography. This work aims to further increase our knowledge of the molecular details of the cleaving mechanism and the typical 1,6- anhydromuropeptide

prevalence of escherichia coli 0157:h7 in fresh and roasted beef

African Journals Online (AJOL)

DR. AMINU

The prevalence of Enterohemorrhagic Escherichia coli 0157:H7 in 300 fresh beef and 150 roasted beef samples from ... likely cause of E. coli O157:H7 infection is undercooked ground beef. ..... coli O157:H7 in a sheep model. Appl. Environ.

GLYCOSYLATED YGHJ POLYPEPTIDES FROM ENTEROTOXIGENIC ESCHERICHIA COLI (ETEC)

DEFF Research Database (Denmark)

2017-01-01

The present invention relates to glycosylated YghJ polypeptides from or derived from enterotoxigenic Escherichia coli (ETEC) that are immunogenic. In particular, the present invention relates to compositions or vaccines comprising the polypeptides and their application in immunization, vaccination...

Purification and Characterization of Recombinant Vaccinia L1R Protein from Escherichia coli

Science.gov (United States)

2016-08-01

RECOMBINANT VACCINIA L1R PROTEIN FROM ESCHERICHIA COLI 1. INTRODUCTION 1.1 Background Vaccinia virus (VACV) is the active component of the...the preparation of the recombinant VACV L1R protein fragment by denaturing , refolding, and purifying material expressed into inclusion bodies in...PURIFICATION AND CHARACTERIZATION OF RECOMBINANT VACCINIA L1R PROTEIN FROM ESCHERICHIA COLI ECBC-TR-1370

Genes and proteins of Escherichia coli K-12.

Science.gov (United States)

Riley, M

1998-01-01

GenProtEC is a database of Escherichia coli genes and their gene products, classified by type of function and physiological role and with citations to the literature for each. Also present are data on sequence similarities among E.coli proteins, representing groups of paralogous genes, with PAM values, percent identity of amino acids, length of alignment and percent aligned. GenProtEC can be accessed at the URL http://www.mbl.edu/html/ecoli.html

Deuterium incorporation into Escherichia-coli proteins

DEFF Research Database (Denmark)

Lederer, H.; May, R. P.; Kjems, Jørgen

1986-01-01

Neutron small-angle scattering studies of single protein subunits in a protein-DNA complex require the adjustment of the neutron scattering-length densities of protein and DNA, which is attainable by specific deuteration of the protein. The neutron scattering densities of unlabelled DNA and DNA......-dependent RNA polymerase of Escherichia coli match when RNA polymerase is isolated from cells grown in a medium containing 46% D2O and unlabelled glucose as carbon source. Their contrasts vanish simultaneously in a dialysis buffer containing 65% D2O. An expression was evaluated which allows the calculation...... of the degree of deuteration and match point of any E. coli protein from the D2O content of the growth medium, taking the 2H incorporation into RNA polymerase amino acids to be representative for all amino acids in E. coli proteins. The small-angle scattering results, on which the calculation of the degree...

Environmental Escherichia coli: ecology and public health implications-a review.

Science.gov (United States)

Jang, J; Hur, H-G; Sadowsky, M J; Byappanahalli, M N; Yan, T; Ishii, S

2017-09-01

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 faeces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent faecal 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 extraintestinal 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 faecal 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 revealed the diversity and complexity of E. coli strains in various environments, which are affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments with regard 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. © 2017 The Society for Applied Microbiology.

Postgenomics Characterization of an Essential Genetic Determinant of Mammary Pathogenic Escherichia coli

Science.gov (United States)

2018-01-01

ABSTRACT Escherichia coli are major bacterial pathogens causing bovine mastitis, a disease of great economic impact on dairy production worldwide. This work aimed to study the virulence determinants of mammary pathogenic E. coli (MPEC). By whole-genome sequencing analysis of 40 MPEC and 22 environmental (“dairy-farm” E. coli [DFEC]) strains, we found that only the fec locus (fecIRABCDE) for ferric dicitrate uptake was present in the core genome of MPEC and that it was absent in DFEC genomes (P mastitis, whereas the fec+ DFEC K71 mutant was able to trigger intramammary inflammation. For the first time, a single molecular locus was shown to be crucial in MPEC pathogenicity. PMID:29615502

The Prevalence of Enterhaemorrhagic Escherichia Coli in children ...

African Journals Online (AJOL)

EHEC), the pathogenicity of other strains of Escherichia coli and other organisms in children presenting with and without diarrhoea in the hospital. Subjects and Methods: A total of 247 stool samples collected from children aged 1 month to 7 ...

Genetic Transfer of Salmonella typhimurium and Escherichia coli Lipopolysaccharide Antigens to Escherichia coli K-12

Science.gov (United States)

Jones, Randall T.; Koeltzow, Donald E.; Stocker, B. A. D.

1972-01-01

Escherichia coli K-12 ϰ971 was crossed with a smooth Salmonella typhimurium donor, HfrK6, which transfers early the ilv-linked rfa region determining lipopolysaccharide (LPS) core structure. Two ilv+ hybrids differing in their response to the LPS-specific phages FO and C21 were then crossed with S. typhimurium HfrK9, which transfers early the rfb gene cluster determining O repeat unit structure. Most recombinants selected for his+ (near rfb) were agglutinated by Salmonella factor 4 antiserum. Transfer of an F′ factor (FS400) carrying the rfb–his region of S. typhimurium to the same two ilv+ hybrids gave similar results. LPS extracted from two ilv+,his+, factor 4-positive hybrids contained abequose, the immunodominant sugar for factor 4 specificity. By contrast, his+ hybrids obtained from ϰ971 itself by similar HfrK9 and F′FS400 crosses were not agglutinated by factor 4 antiserum, indicating that the parental E. coli ϰ971 does not have the capacity to attach Salmonella O repeat units to its LPS core. It is concluded that the Salmonella rfb genes are expressed only in E. coli ϰ971 hybrids which have also acquired ilv-linked genes (presumably rfa genes affecting core structure or O-translocase ability, or both) from a S. typhimurium donor. When E. coli ϰ971 was crossed with a smooth E. coli donor, Hfr59, of serotype O8, which transfers his early, most his+ recombinants were agglutinated by E. coli O8 antiserum and lysed by the O8-specific phage, Ω8. This suggests that, although the parental E. coli K-12 strain ϰ971 cannot attach Salmonella-specific repeat units to its LPS core, it does have the capacity to attach E. coli O8-specific repeat units. PMID:4559827

Escherichia coli O157:H7 - An Emerging Pathogen in foods of Animal Origin

Directory of Open Access Journals (Sweden)

Ch. Bindu Kiranmayi

Full Text Available Escherichia coli O157:H7 is an emerging public health concern in most countries of the world. E. coli O157:H7 was known to be a human pathogen for nearly 24 years. EHEC O157 infection is estimated to be the fourth most costly food borne disease in Canada and USA, not counting the cost of possible litigation. E. coli O157:H7 and Salmonella are the leading causes of produce related outbreaks, accounting for 20 and 30% respectively. The authority of the Federal Meat Inspection Act, FSIS (Food Safety and Inspection Service declared Escherichia coli O157:H7, an adulterant in raw ground beef and enforced “zero tolerance” (USDA-FSIS, 17 December 1998. Because of the severity of these illnesses and the apparent low infective dose (less than 10 cells, Escherichia coli O157:H7 is considered one of the most serious of known food borne pathogens. Escherichia coli O157:H7 is mainly pathogenic to human but in cattle and other animals, it did not induce any clinical disease except diarrhea. So, these animals act as carriers to Escherichia coli O157:H7. The majority transmission is through eating of undercooked contaminated ground meat and consumption of raw milk, raw vegetables, fruits contaminated by water, cheese, curd and also through consumption of sprouts, lettuce and juice. The conventional isolation procedure includes growth in enrichment broth like modified EC (E. coli broth or modified tryptic soy broth (mTSB Since the infection primarily occurs via faeco-oral route, the preventive measures include food hygiene measures like proper cooking of meat, consumption of pasteurized milk, washing fruits and vegetables especially those to be eaten raw and drinking chlorine treated water and personnel hygiene measures like washing hands after toilet visits. [Veterinary World 2010; 3(8.000: 382-389

Mechanisms of antibiotic resistance to enrofloxacin in uropathogenic Escherichia coli in dog

Science.gov (United States)

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...

Occurrence of adhesin-encoding operons in Escherichia coli isolated from breeders with salpingitis and chicks with omphalitis Ocorrência de operons codificadores de adesinas em Escherichia coli isolada de aves reprodutoras com salpingite e de pintinhos com onfalite

Directory of Open Access Journals (Sweden)

Terezinha Knöbl

2006-06-01

Full Text Available The occurrence of fim, pap and sfa operons in Escherichia coli isolated from breeders with salpingitis and chicks with omphalitis was evaluated. Analysis of 100 E. coli isolates, by colony hybridization tests, showed that 78 (78% were fim+, one (1% was sfa+, seven (7% were fim+ associated with pap+, eigth (8% were fim+ and sfa+, one (1% was fim+pap+sfa+ and five (5% isolates did not hybridize with any probe. These results suggest that fim adhesion-encoding operon plays an important role in pathogenesis of E. coli infection in chickens with salpingitis and omphalitis.Ocorrência dos operons fim, pap e sfa em amostras de Escherichia coli isoladas de reprodutoras com salpingite e pintinhos com onfalite foi avaliada. A análise de 100 amostras através dos testes de hibridização de colônia mostrou que 78 (78% amostras eram fim+, uma (1% era sfa+, sete (7% eram fim+ associada a pap+, oito (8% eram fim+ e uma (1% era fim+pap+sfa+ e cinco (5% amostras não hibridizaram com nenhuma sonda. Estes resultados sugerem que o operon fim pode ter um importante papel na patogenia da infecção de Escherichia coli em reprodutoras com salpingite e pintinhos com onfalite.

Spontaneous Escherichia coli Meningitis Associated with Hemophagocytic Lymphohistiocytosis

Directory of Open Access Journals (Sweden)

Kuo-Hsuan Chang

2006-01-01

Full Text Available Spontaneous Escherichia coli meningitis has not been previously reported in association with hemophago-cytic lymphohistiocytosis (HLH. A previously healthy 72-year-old woman was admitted due to fever, nuchal rigidity, disturbed consciousness and splenomegaly. Anemia, thrombocytopenia and hyperfer-ritinemia developed on the 8th day of hospitalization. Cultures of cerebrospinal fluid and blood grew E. coli. Abundant macrophages overwhelmed erythrocytes in the bone marrow aspirate, confirming the presence of hemophagocytosis. E. coli meningitis was managed with a 40-day course of antibiotic treatment. However, the severity of anemia and thrombocytopenia progressed despite intensive transfusion therapy. The patient died of HLH on the 60th day of hospitalization.

Study of the effects of high-energy proton beams on escherichia coli

Science.gov (United States)

Park, Jeong Chan; Jung, Myung-Hwan

2015-10-01

Antibiotic-resistant bacterial infection is one of the most serious risks to public health care today. However, discouragingly, the development of new antibiotics has progressed little over the last decade. There is an urgent need for alternative approaches to treat antibiotic-resistant bacteria. Novel methods, which include photothermal therapy based on gold nano-materials and ionizing radiation such as X-rays and gamma rays, have been reported. Studies of the effects of high-energy proton radiation on bacteria have mainly focused on Bacillus species and its spores. The effect of proton beams on Escherichia coli (E. coli) has been limitedly reported. Escherichia coli is an important biological tool to obtain metabolic and genetic information and is a common model microorganism for studying toxicity and antimicrobial activity. In addition, E. coli is a common bacterium in the intestinal tract of mammals. In this research, the morphological and the physiological changes of E. coli after proton irradiation were investigated. Diluted solutions of cells were used for proton beam radiation. LB agar plates were used to count the number of colonies formed. The growth profile of the cells was monitored by using the optical density at 600 nm. The morphology of the irradiated cells was observed with an optical microscope. A microarray analysis was performed to examine the gene expression changes between irradiated samples and control samples without irradiation. E coli cells have observed to be elongated after proton irradiation with doses ranging from 13 to 93 Gy. Twenty-two were up-regulated more than twofold in proton-irradiated samples (93 Gy) compared with unexposed one.

Identification of Escherichia coli and Shigella Species from Whole-Genome Sequences.

Science.gov (United States)

Chattaway, Marie A; Schaefer, Ulf; Tewolde, Rediat; Dallman, Timothy J; Jenkins, Claire

2017-02-01

Escherichia coli and Shigella species are closely related and genetically constitute the same species. Differentiating between these two pathogens and accurately identifying the four species of Shigella are therefore challenging. The organism-specific bioinformatics whole-genome sequencing (WGS) typing pipelines at Public Health England are dependent on the initial identification of the bacterial species by use of a kmer-based approach. Of the 1,982 Escherichia coli and Shigella sp. isolates analyzed in this study, 1,957 (98.4%) had concordant results by both traditional biochemistry and serology (TB&S) and the kmer identification (ID) derived from the WGS data. Of the 25 mismatches identified, 10 were enteroinvasive E. coli isolates that were misidentified as Shigella flexneri or S. boydii by the kmer ID, and 8 were S. flexneri isolates misidentified by TB&S as S. boydii due to nonfunctional S. flexneri O antigen biosynthesis genes. Analysis of the population structure based on multilocus sequence typing (MLST) data derived from the WGS data showed that the remaining discrepant results belonged to clonal complex 288 (CC288), comprising both S. boydii and S. dysenteriae strains. Mismatches between the TB&S and kmer ID results were explained by the close phylogenetic relationship between the two species and were resolved with reference to the MLST data. Shigella can be differentiated from E. coli and accurately identified to the species level by use of kmer comparisons and MLST. Analysis of the WGS data provided explanations for the discordant results between TB&S and WGS data, revealed the true phylogenetic relationships between different species of Shigella, and identified emerging pathoadapted lineages. © Crown copyright 2017.

Affinity isolation and I-DIRT mass spectrometric analysis of the Escherichia coli O157:H7 Sakai RNA polymerase complex.

Science.gov (United States)

Lee, David J; Busby, Stephen J W; Westblade, Lars F; Chait, Brian T

2008-02-01

Bacteria contain a single multisubunit RNA polymerase that is responsible for the synthesis of all RNA. Previous studies of the Escherichia coli K-12 laboratory strain identified a group of effector proteins that interact directly with RNA polymerase to modulate the efficiency of transcription initiation, elongation, or termination. Here we used a rapid affinity isolation technique to isolate RNA polymerase from the pathogenic Escherichia coli strain O157:H7 Sakai. We analyzed the RNA polymerase enzyme complex using mass spectrometry and identified associated proteins. Although E. coli O157:H7 Sakai contains more than 1,600 genes not present in the K-12 strain, many of which are predicted to be involved in transcription regulation, all of the identified proteins in this study were encoded on the "core" E. coli genome.

The antibacterial effect of four mouthwashes against streptococcus mutans and escherichia coli.

Science.gov (United States)

Ghapanchi, Janan; Lavaee, Fatemeh; Moattari, Afagh; Shakib, Mahmood

2015-04-01

To evaluate the antimicrobial properties of several mouthwash concentrations on oral Streptococcus mutans and Escherichia coli. The study was conducted at Shiraz Medicine School in 2011. Serial dilutions of Chlorohexidin, Oral B and Persica and Irsha (2,4,8,16,64,128) were prepared in Muller-Hinton media. Minimum inhibitory concentration was visually determined and defined as the lowest concentration of each oral washing which inhibited > 95% growth reduction compared to the growth control well. Chlorhexidine, Oral B and Irsha mouthwash inhibited Streptococcus mutans even with diluted concentrations. Also, Chlorhexidine and Oral B prohibited Escherichia coli with different potencies. But Persica had no antimicrobial activity against either Escherichia coli or Streptococcus mutans. Chlorhexidine, Irsha, and Oral B mouthwashes can be used for antimicrobial effects, especially on Streptococcus mutans. This chemical activity of mouthwashes is an adjuvant for mechanical removing of plaque. However, the antimicrobial effect of Persicaremains controversial.

Escherichia coli Contamination of Lettuce Grown in Soils Amended with Animal Slurry

DEFF Research Database (Denmark)

Jensen, Annette Nygaard; Storm, Christina; Forslund, Anita

2013-01-01

A pilot study was conducted to assess the transfer of Escherichia coli from animal slurry fertilizer to lettuce, with E. coli serving as an indicator of fecal contamination and as an indicator for potential bacterial enteric pathogens. Animal slurry was applied as fertilizer to three Danish agric...... types between slurry, soil, and lettuce. The frequent finding of fecal-contaminated lettuce indicates that human pathogens such as Salmonella and Campylobacter can be present and represent food safety hazards.......A pilot study was conducted to assess the transfer of Escherichia coli from animal slurry fertilizer to lettuce, with E. coli serving as an indicator of fecal contamination and as an indicator for potential bacterial enteric pathogens. Animal slurry was applied as fertilizer to three Danish....... coli. A relatively higher frequency of E. coli in lettuce compared with the soil samples at harvest suggests environmental sources of fecal contamination, e.g., wildlife. The higher frequency was supported by the finding of 21 different PFGE types among the E. coli isolates, with only a few common PFGE...

Characterization of diarrhoeagenic Escherichia coli isolates in Jordanian children.

Science.gov (United States)

Shehabi, Asem A; Bulos, Najawa-Kuri; Hajjaj, Kamal G

2003-01-01

In a prospective study carried out among Jordanian children in Amman, a total of 73/250 (29.2%) stool specimens were positive for 1 or more diarrhoeagenic Escherichia coli strains using a multiplex polymerase chain reaction method. This study indicated that diarrhoeagenic E. coli isolates were found frequently more in stools of children with diarrhoea (34%) than without diarrhoea (23.1%), but without any significant difference (p > 0.05). The predominant diarrhoeagenic E. coli strains associated with diarrhoea were enteropathogenic E. coli (11.3%), followed by enterotoxigenic E. coli (9.8%) and enteroaggrative E. coli (9%), whereas in the control group these were 4.3%, 11.1% and 6%, respectively. Enteroinvasive E. coli strains (2.9%) were found only in stools of children with diarrhoea. This study revealed the absence of enterohaemorrhagic E. coli in both diarrhoeal and control stools, and found that diarrhoeagenic E. coli isolates were highly resistance to tetracycline (55%), co-trimoxazole (60%) and ampicillin (89%), which are commonly used antibiotics in Jordan.

Vanillin production by recombinant strains of Escherichia coli Produção de vanilina por linhagens recombinantes de Escherichia coli

Directory of Open Access Journals (Sweden)

Attilio Converti

2003-11-01

Full Text Available Vanillin production from ferulate was studied using different recombinant strains of Escherichia coli. To prevent the occurrence of aerobic conditions and then possible product oxidation, tests were performed in Erlenmeyer flasks under mild mixing (150 rpm. Among other transformants, E. coli JM109(pBB1 appeared to be the best vanillin producer, being able to convert no less than 95% of starting ferulate to the product within 1h. This yield decreased down to 72% after 72h, likely because of a non-specific oxidase activity responsible for vanillin oxidation to vanillate.A produção de vanilina a partir de ácido ferúlico foi estudada utilizando-se diferentes linhagens recombinantes de Escherichia coli. Para prevenir a ocorrência de condições de aerobiose e a possível oxidação do produto, os ensaios foram realizados em frascos Erlenmeyer sob agitação moderada (150 rpm. E. coli JM109 (pBBI mostrou-se o melhor produtor de vanilina entre os demais agentes transformantes, sendo capaz de converter 95% do ácido ferúlico inicial em produto após 1h, rendimento este que decresceu para 72% após 72h, provavelmente devido à atividade de uma oxidase não-específica responsável pela oxidação de vanilina a ácido vanílico.

Identification of Genes Important for Growth of Asymptomatic Bacteriuria Escherichia coli in Urine

DEFF Research Database (Denmark)

Vejborg, Rebecca Munk; de Evgrafov, Mari Cristina Rodriguez; Phan, Minh Duy

2012-01-01

Escherichia coli is the most important etiological agent of urinary tract infections (UTIs). Unlike uropathogenic E. coli, which causes symptomatic infections, asymptomatic bacteriuria (ABU) E. coli strains typically lack essential virulence factors and colonize the bladder in the absence...

Autolysis of Escherichia coli and Bacillus subtilis cells in low gravity

Science.gov (United States)

Kacena, M. A.; Smith, E. E.; Todd, P.

1999-01-01

The role of gravity in the autolysis of Bacillus subtilis and Escherichia coli was studied by growing cells on Earth and in microgravity on Space Station Mir. Autolysis analysis was completed by examining the death phase or exponential decay of cells for approximately 4 months following the stationary phase. Consistent with published findings, the stationary-phase cell population was 170% and 90% higher in flight B. subtilis and E. coli cultures, respectively, than in ground cultures. Although both flight autolysis curves began at higher cell densities than control curves, the rate of autolysis in flight cultures was identical to that of their respective ground control rates.

Enteroaggregative Escherichia coli in Daycare

DEFF Research Database (Denmark)

Hebbelstrup Jensen, Betina; Stensvold, Christen R.; Struve, Carsten

2016-01-01

Enteroaggregative Escherichia coli (EAEC) has been associated with persistent diarrhea, reduced growth acceleration, and failure to thrive in children living in developing countries and with childhood diarrhea in general in industrialized countries. The clinical implications of an EAEC carrier...... and answered a questionnaire regarding gastrointestinal symptoms and exposures. Exposures included foreign travel, consumption of antibiotics, and contact with a diseased animal. In the capital area of Denmark, a total of 179 children aged 0-6 years were followed in a cohort study, in the period between 2009...

Action of sodium deoxycholate on Escherichia coli

International Nuclear Information System (INIS)

D'Mello, A.; Yotis, W.W.

1987-01-01

Sodium deoxycholate is used in a number of bacteriological media for the isolation and classification of gram-negative bacteria from food and the environment. Initial experiments to study the effect of deoxycholate on the growth parameters of Escherichia coli showed an increase in the lag time constant and generation time and a decrease in the growth rate constant total cell yield of this microorganisms. Cell fractionation studies indicated that sodium deoxycholate at levels used in bacteriological media interferes with the incorporation of [U- 14 C]glucose into the cold-trichloroacetic acid-soluble, ethanol-soluble, and trypsin-soluble cellular fractions of E. coli. Finally, sodium deoxycholate interfered with the flagellation and motility of Proteus mirabilis and E. coli. It would appear then that further improvement of the deoxycholate medium may be in order

Action of sodium deoxycholate on Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

D' Mello, A.; Yotis, W.W.

1987-08-01

Sodium deoxycholate is used in a number of bacteriological media for the isolation and classification of gram-negative bacteria from food and the environment. Initial experiments to study the effect of deoxycholate on the growth parameters of Escherichia coli showed an increase in the lag time constant and generation time and a decrease in the growth rate constant total cell yield of this microorganisms. Cell fractionation studies indicated that sodium deoxycholate at levels used in bacteriological media interferes with the incorporation of (U-/sup 14/C)glucose into the cold-trichloroacetic acid-soluble, ethanol-soluble, and trypsin-soluble cellular fractions of E. coli. Finally, sodium deoxycholate interfered with the flagellation and motility of Proteus mirabilis and E. coli. It would appear then that further improvement of the deoxycholate medium may be in order.

Temporal variations of Escherichia coli concentrations in a large Midwestern river

Science.gov (United States)

Schilling, K.E.; Zhang, Y.-K.; Hill, D.R.; Jones, C.S.; Wolter, C.F.

2009-01-01

The Raccoon River used by the Des Moines Water Works to serve more than 400,000 people in central Iowa is threatened by contamination from Escherichia coli bacteria from point and nonpoint sources. The 9389 km2 watershed is highly agricultural, with 73% of the land in row crop production and widespread animal production. Results from 2155 grab samples from 1997 to 2005 for E. coli analysis were examined for temporal variations. E. coli concentrations were found to vary across years, seasons, and flow conditions, with a 9-year mean value of 1156 most probable number (MPN)/100 ml. Monthly concentrations exhibited clear seasonality with highest values in May through July. Although E. coli concentrations were higher during periods of greater discharge, the relation of log E. coli to log discharge was not particularly strong (r2 = 0.35). The variogram of E. coli concentrations showed temporal correlation within a span of 4 days suggesting that concentrations measured on 1 day may be related in time to concentrations measured up to 3 days later and beyond 4 days the concentrations vary randomly. The spectral analysis of the time series of E. coli was also carried out and was fitted well with the spectrum of an exponential covariance function. Deciphering temporal patterns and correlation of E. coli bacteria in streams may be useful for developing future monitoring strategies to track concentration patterns and loads. ?? 2008 Elsevier B.V. All rights reserved.

Draft Genome Sequence of Escherichia coli K-12 (ATCC 10798)

OpenAIRE

Dimitrova, Daniela; Engelbrecht, Kathleen C.; Putonti, Catherine; Koenig, David W.; Wolfe, Alan J.

2017-01-01

ABSTRACT Here, we present the draft genome sequence of Escherichia coli ATCC 10798. E.?coli ATCC 10798 is a K-12 strain, one of the most well-studied model microorganisms. The size of the genome was 4,685,496?bp, with a G+C content of 50.70%. This assembly consists of 62 contigs and the F plasmid.

Protein export in bacillus subtilis and escherichia coli

NARCIS (Netherlands)

Dijl, Jan Maarten van

1990-01-01

The export of heterologous proteins in Bacillus subtilis and Escherichia coli is often inefficient. Frequently observed problems are: 1) accumulation of the precursor form of the exported protein in the cytoplasm or in the membrane; 2), inefficient or incorrect processing of the precursor; 3),

The level of Escherichia coli contamination in foods and drinks sold at canteens campus

Directory of Open Access Journals (Sweden)

Dewi Susanna

2011-02-01

Full Text Available Background: Bacterial contamination is a common phenomenon in foods served in campus canteens and my cause physical illness which will affect academic activity. The aim of this study was to rank the level of Escherichia coli contamination in food and drink in campus canteens.Methods: Forty nine (49 foods and 24 types of drink were examined using conventional agar broth method for calculation of most probable number (MPN. The steps of the mothod were presumptive test for coliforms, fecal coliforms and E. coli, confirmes test for coliforms, fecal coli and E. coli and then completed test for E. coli. An analysis for contamination by E. coli in meals, utensils, and on the hands of the server was also undertaken. The data analyzed in percentage and rank all type of foods and drinks, also rank based on the location.Results: Almost all type of meals was contaminated. Meals with chili sauce were the most risky from the contamination of E. coli (90.15 %, then followed by dry meals (38.89%, while the wet meals were the the most unrisky meals. In  drinks, the highest was lacy juice, followed by jambu (guava juice, then Sirsak and Orange juices on the third rank, while the mango juice was the lowest contamination. Melon juice, cappucino and fruit-coctail did not have E. coli  contamination.Conclusion: The contamination in the top three rank of contamination could be from the utensils used and foodhandler. (Med J Indones 2011; 20:66-70Keywords: campus, canteen, drink, Escherichia coli, food

Production of caffeoylmalic acid from glucose in engineered Escherichia coli.

Science.gov (United States)

Li, Tianzhen; Zhou, Wei; Bi, Huiping; Zhuang, Yibin; Zhang, Tongcun; Liu, Tao

2018-07-01

To achieve biosynthesis of caffeoylmalic acid from glucose in engineered Escherichia coli. We constructed the biosynthetic pathway of caffeoylmalic acid in E. coli by co-expression of heterologous genes RgTAL, HpaBC, At4CL2 and HCT2. To enhance the production of caffeoylmalic acid, we optimized the tyrosine metabolic pathway of E. coli to increase the supply of the substrate caffeic acid. Consequently, an E. coli-E. coli co-culture system was used for the efficient production of caffeoylmalic acid. The final titer of caffeoylmalic acid reached 570.1 mg/L. Microbial production of caffeoylmalic acid using glucose has application potential. In addition, microbial co-culture is an efficient tool for producing caffeic acid esters.

A sustainable route to produce the scytonemin precursor using Escherichia coli

DEFF Research Database (Denmark)

Malla, Sailesh; Sommer, Morten O. A.

2014-01-01

moiety of scytonemin from tryptophan and tyrosine in Escherichia coli. We heterologously expressed the biosynthetic pathway from Nostoc punctiforme and discovered that only three enzymes from N. punctiforme are required for the in vivo production of the monomer moiety of scytonemin in E. coli. We also...

Affinity Isolation and I-DIRT Mass Spectrometric Analysis of the Escherichia coli O157:H7 Sakai RNA Polymerase Complex▿

Science.gov (United States)

Lee, David J.; Busby, Stephen J. W.; Westblade, Lars F.; Chait, Brian T.

2008-01-01

Bacteria contain a single multisubunit RNA polymerase that is responsible for the synthesis of all RNA. Previous studies of the Escherichia coli K-12 laboratory strain identified a group of effector proteins that interact directly with RNA polymerase to modulate the efficiency of transcription initiation, elongation, or termination. Here we used a rapid affinity isolation technique to isolate RNA polymerase from the pathogenic Escherichia coli strain O157:H7 Sakai. We analyzed the RNA polymerase enzyme complex using mass spectrometry and identified associated proteins. Although E. coli O157:H7 Sakai contains more than 1,600 genes not present in the K-12 strain, many of which are predicted to be involved in transcription regulation, all of the identified proteins in this study were encoded on the “core” E. coli genome. PMID:18083804

Characterization of extraintestinal Escherichia coli isolated from a peacock (Pavo cristatus) with colisepticemia.

Science.gov (United States)

Barbieri, Nicolle Lima; Tejkowski, Thiago Moreira; de Oliveira, Aline Luisa; de Brito, Benito Guimarães; Horn, Fabiana

2012-06-01

Extraintestinal infections by avian pathogenic strains of Escherichia coli (APEC) are commonly reported in poultry, but there is little information on infections by APEC in other bird species. Here we report on the characterization of extraintestinal E. coli isolated from a domesticated peacock, from the south of Brazil, that died of colisepticemia. Necropsy examination revealed congested liver, hypertrophied kidneys, peritonitis, severe typhlitis suggestive of coligranuloma, pneumonia, and airsacculitis--typical signs of colisepticemia. The isolates from lungs, kidney, heart, intestine, liver, and bone marrow all harbored the same virulence-associated factors (iucD, colV, iss, mat, fimC, ompA, traT crl, csgA vgrG, and hcp), yielded the same band pattern in amplified ribosomal DNA restriction analysis, and were allocated to the Escherichia coli Reference Collection group B1. The isolates were resistant to bacitracin, trimethoprim, and tetracycline, but displayed slight differences in their resistance to other antimicrobials. The isolates also differed in their virulence in 1-day-old chickens, but none displayed high virulence in vivo. We conclude that the peacock died of colisepticemia after it was infected with an extraintestinal E. coli strain of low virulence that nevertheless harbored virulence factors generally associated with APEC. This study represents the first characterization of an APEC isolated from a nonpoultry bird species.

Identification and localization of a gene that specifies production of Escherichia coli DNA topoisomerase I

International Nuclear Information System (INIS)

Trucksis, M.; Depew, R.E.

1981-01-01

A gene that specifies production of Escherichia coli DNA topoisomerase I (ω protein) was identified with the aid of a radioimmunoassay for this protein. E. coli DNA topoisomerase I was produced by Salmonella typhimurium merodiploids that harbored E. coli plasmid F' 123, but not by strains that lost this plasmid. Analysis of strains with spontaneous deletions of F' 123 showed that the gene, topA, required for production of the E. coli ω protein was between the trp operon and the cysB gene. Deletions that eliminated topA also eliminated the supX gene. We suggest that topA is the structural gene of E. coli DNA topoisomerase I and that topA is identical to supX

Controlled initiation of chromosomal replication in Escherichia coli requires functional Hda protein.

Science.gov (United States)

Camara, Johanna Eltz; Skarstad, Kirsten; Crooke, Elliott

2003-05-01

Regulatory inactivation of DnaA helps ensure that the Escherichia coli chromosome is replicated only once per cell cycle, through accelerated hydrolysis of active replication initiator ATP-DnaA to inactive ADP-DnaA. Analysis of deltahda strains revealed that the regulatory inactivation of DnaA component Hda is necessary for maintaining controlled initiation but not for cell growth or viability.

Establishing Streptomycin Epidemiological Cut-Off Values for Salmonella and Escherichia coli

DEFF Research Database (Denmark)

Migura, Lourdes Garcia; Sunde, Marianne; Karlsmose, Susanne

2011-01-01

This study was conducted to elucidate the accuracy of the current streptomycin epidemiological cut-off value (ECOFF) for Escherichia coli and Salmonella spp. A total of 236 Salmonella enterica and 208 E. coli isolates exhibiting MICs between 4 and 32 mg/L were selected from 12 countries. Isolates...

TEM-145 and TEM-146 β-lactamases produced by Escherichia coli ...

African Journals Online (AJOL)

GREGO

2007-03-05

Mar 5, 2007 ... Key words: Escherichia coli, plasmid-mediated, TEM β-lactamase. ... Enterobacteriaceae, the most prevalent mechanism of resistance to ... the production of a relatively inhibitor-resistant OXA-type β-lactamase .... and 8.6 as transcripts of the E. coli chromosomal AmpC .... Mode of action and mechanisms of.

Pulsed-Plasma Disinfection of Water Containing Escherichia coli

Science.gov (United States)

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.

ANALISIS KANDUNGAN BORAKS DAN Escherichia coli PADA JAJANAN BAKSO SAPI YANG DIPERDAGANGKAN DI KOTA BANJARBARU

Directory of Open Access Journals (Sweden)

Nur Rahmi

2016-09-01

Full Text Available This study aims to determine how the content of borax and Escherichia coli on meatballs snacks and the factors that affect the food security of meatballs snacks by using Easy Method of Borax Test and Method of Most Probable Number (MPN for Escherichia coli bacteria contamination. This research was conducted in Banjarbaru on 5 villages, and sampling technique used is stratified sampling. The results of the study showed that from 32 samples taken from five village location, it was not identified any borax based on PERMENKES No. 033 of 2012, while for the examination of Escherichia coli, there are 14 samples of meatballs (43.75% which were eligible, and 18 samples of meatballs (56.25% which containEscherichia coli ranges from 3.6 to 62 CFU /g or not meeting the criteria of ISO 7388: 2009. The factor that might not trigger the addition of borax is that the traders have a good knowledge and attitude toward borax which regarded as a toxic substance and can be harmful to health. Factors that cause microbial contamination of Escherichia coli on meatballs snacks is the lack of food hygiene and sanitation in the food processing, cooked food storage, transport, serving, sanitation facilities, and personnel handlers compared with the good supply of foodstuffs and food ingredients storage.

In depth analysis of genes and pathways of the mammary gland involved in the pathogenesis of bovine Escherichia coli-mastitis

DEFF Research Database (Denmark)

Buitenhuis, Albert Johannes; Rontved, Christine M.; Edwards, Stefan McKinnon

2011-01-01

Background Bovine mastitis is one of the most costly and prevalent diseases affecting dairy cows worldwide. In order to develop new strategies to prevent Escherichia coli-induced mastitis, a detailed understanding of the molecular mechanisms underlying the host immune response to an E. coli.......i. to represent the acute phase response (APR) and chronic stage, respectively. Differentially expressed (DE) genes for each stage were analyzed and the DE genes detected at T=24h were also compared to data collected from two previous E. coli mastitis studies that were carried out on post mortem tissue. Results...... of the up-regulated transcripts were associated with tissue healing processes. Comparison of T=24h DE genes detected in the three E. coli mastitis studies revealed 248 were common and mainly involved immune response functions. KEGG pathway analysis indicated these genes were involved in 12 pathways related...

Escherichia coli O104 associated with human diarrhea, South Africa, 2004-2011.

Science.gov (United States)

Tau, Nomsa P; Meidany, Parastu; Smith, Anthony M; Sooka, Arvinda; Keddy, Karen H

2012-08-01

To determine the origin of >4,000 suspected diarrheagenic Escherichia coli strains isolated during 2004-2011 in South Africa, we identified 7 isolates as serotype O104; 5 as enteroaggregative E. coli O104:H4, and 2 as enteropathogenic E. coli O104:non-H4. Pulsed-field gel electrophoresis showed that these isolates were unrelated to the 2011 E. coli O104:H4 outbreak strain from Germany.

The Development of a Portable SPR Bioanalyzer for Sensitive Detection of Escherichia coli O157:H7

Directory of Open Access Journals (Sweden)

Shun Wang

2016-11-01

Full Text Available The purpose of this study was to develop a portable surface plasmon resonance (SPR bioanalyzer for the sensitive detection of Escherichia coli O157:H7 in comparison with an enzyme-linked immunosorbent assay (ELISA. The experimental setup mainly consisted of an integrated biosensor and a homemade microfluidic cell with a three-way solenoid valve. In order to detect Escherichia coli O157:H7 using the SPR immunoassay, 3-mercaptopropionic acid (3-MPA was chemisorbed onto a gold surface via covalent bond for the immobilization of biological species. 1-ethyl-3-(3-dimethylaminopropyl carbodiimide hydrochloride (EDC and N-hydroxysuccinimide (NHS were used as crosslinker reagents to enable the reaction between 3-MPA and Escherichia coli O157:H7 antibodies by covalent –CO–NH– amide bonding. The experimental results were obtained from the Escherichia coli O157:H7 positive samples prepared by 10-, 20-, 40-, 80-, and 160-fold dilution respectively, which show that a good linear relationship with the correlation coefficient R of 0.982 existed between the response units from the portable SPR bioanalyzer and the concentration of Escherichia coli O157:H7 positive samples. Moreover, the theoretical detection limit of 1.87 × 103 cfu/mL was calculated from the positive control samples. Compared with the Escherichia coli O157:H7 ELISA kit, the sensitivity of this portable SPR bioanalyzer is four orders of magnitude higher than the ELISA kit. The results demonstrate that the portable SPR bioanalyzer could provide an alternative method for the quantitative and sensitive determination of Escherichia coli O157:H7 in field.

Cytokine response to Escherichia coli in gnotobiotic pigs

Czech Academy of Sciences Publication Activity Database

Šplíchal, Igor; Šplíchalová, Alla; Trebichavský, Ilja

2008-01-01

Roč. 53, č. 2 (2008), s. 161-164 ISSN 0015-5632 R&D Projects: GA ČR GA523/05/0249 Institutional research plan: CEZ:AV0Z50200510 Keywords : germ-free pigs * escherichia coli * cytokine response Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008

Escherichia coli and virus isolated from ''sticky kits''

DEFF Research Database (Denmark)

Jørgensen, M.; Scheutz, F.; Strandbygaard, Bertel

1996-01-01

A total of 121 Escherichia coli strains isolated from 3-week-old mink kits were serotyped and examined for virulence factors. 56 strains were isolated from healthy kits while 65 were from ''sticky kits''. Among these, 34 different serotypes were detected. No difference in serotypes or the presenc...

Frequency and risk-factors analysis of Escherichia coli O157:H7 in Bali-cattle.

Science.gov (United States)

Suardana, I Wayan; Widiasih, Dyah Ayu; Nugroho, Widagdo Sri; Wibowo, Michael Haryadi; Suyasa, I Nyoman

2017-08-01

Cattle are known as the main reservoir of zoonotic agents verocytotoxin-producing Escherichia coli. These bacteria are usually isolated from calves with diarrhea and/or mucus and blood. Tolerance of these agents to the environmental conditions will strengthen of their transmission among livestock. A total of 238 cattle fecal samples from four sub-districts in Badung, Bali were used in this study. Epidemiological data observed include cattle age, sex, cattle rearing system, the source of drinking water, weather, altitude, and type of cage floor, the cleanliness of cage floor, the slope of cage floor, and the level of cattle cleanliness. The study was initiated by culturing of samples onto eosin methylene blue agar, then Gram stained, and tested for indole, methyl-red, voges proskauer, and citrate, Potential E.coli isolates were then cultured onto sorbitol MacConkey agar, and further tested using O157 latex agglutination test and H7 antisera. Molecular identification was performed by analysis of the 16S rRNA gene, and epidemiological data was analyzed using STATA 12.0 software. The results showed, the prevalence of E. coli O157:H7 in cattle at Badung regency was 6.30% (15/238) covering four sub districts i.e. Petang, Abiansemal, Mengwi, and Kuta which their prevalence was 8.62%(5/58), 10%(6/60), 3.33%(2/60), and 3.33(2/60)%, respectively. The analysis of 16S rRNA gene confirmed of isolates as an E. coli O157:H7 strain with 99% similarities. Furthermore, the risk factors analysis showed that the slope of the cage floor has a highly significant effect (P<0.05) to the distribution of infection. Consequently, implementing this factor must be concerned in order to decrease of infection. Copyright © 2017 Elsevier B.V. All rights reserved.

TiO2 Photocatalysis Damages Lipids and Proteins in Escherichia coli

NARCIS (Netherlands)

Carre, Gaelle; Hamon, Erwann; Ennahar, Said; Estner, Maxime; Lett, Marie-Claire; Horvatovich, Peter; Gies, Jean-Pierre; Keller, Valerie; Keller, Nicolas; Andre, Philippe

This study investigates the mechanisms of UV-A (315 to 400 nm) photocatalysis with titanium dioxide (TiO2) applied to the degradation of Escherichia coli and their effects on two key cellular components: lipids and proteins. The impact of TiO2 photocatalysis on E. coli survival was monitored by

Multiple Antibiotic Resistance Patterns of Escherichia coli Isolates from Swine Farms

OpenAIRE

Mathew, A. G.; Saxton, A. M.; Upchurch, W. G.; Chattin, S. E.

1999-01-01

Antibiotic resistance of Escherichia coli from sows and pigs was determined to compare patterns between pigs of various ages and degrees of antibiotic use. Resistance patterns differed between farm types and pigs of differing ages, indicating that pig age and degree of antibiotic use affect resistance of fecal E. coli.

Escherichia coli: a brief review of diarrheagenic pathotypes and their role in diarrheal diseases in Iran

Science.gov (United States)

Jafari, A; Aslani, MM; Bouzari, S

2012-01-01

Diarrheagenic Escherichia coli have developed different strategies for establishment of infection in their host. Understanding these pathogenic mechanisms has led to the development of specific diagnostic tools for identification and categorization of E. coli strains into different pathotypes. This review aims to provide an overview of the various categories of diarrheagenic Escherichia coli and the data obtained in Iran pertaining to these pathotypes. PMID:23066484

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Toxicity mechanism of carbon nanotubes on Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Young, Yu-Fu [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Lee, Hui-Ju [Department of Life Science, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Shen, Yi-Shan; Tseng, Shih-Hao; Lee, Chi-Young [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Tai, Nyan-Hwa, E-mail: nhtai@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Chang, Hwan-You, E-mail: hychang@mx.nthu.edu.tw [Department of Life Science, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

2012-05-15

Highlights: Black-Right-Pointing-Pointer F-MWCNTs possess higher antibiotic performance than that of the F-SWCNTs. Black-Right-Pointing-Pointer E. coli cells were pierced when incubated with F-MWCNTs and trapped when incubated with F-SWCNTs. Black-Right-Pointing-Pointer The rigidity and moment of CNTs play important role on the antibiotic effect. - Abstract: The influences of carbon nanomaterials on bacteria were investigated using three types of dispersed and functionalized carbon nanomaterials (F-CNMs), viz. functionalized carbon nanopowder (F-CNP), functionalized single-walled carbon nanotubes (F-SWCNTs), and functionalized multi-walled carbon nanotubes (F-MWCNTs). F-CNMs with different aspect ratios were used to study the influence of material configuration on the viability of Escherichia coli (E. coli). Although these materials were functionalized to improve their dispersibility, the original morphologies and chemical properties of the materials were maintained. Traditional bacteria quantitative plating analysis was conducted, and the results of which revealed that the F-CNP and the F-SWCNTs showed a less significant effect on the viability of E. coli, while the F-MWCNTs obviously inhibited cell viability. A Fourier transform infrared spectroscopy and a scanning electron microscopy were used to verify the functionalization of the F-CNMs and to examine the interaction of F-CNMs with E. coli, respectively; in addition, we adopted chemiluminescence assays to measure the concentration of adenosine triphosphate (ATP) released from the damaged cells. The results showed that the ATP of the F-MWCNTs sample is two-fold higher than that of the control, indicating direct piercing of E. coli by F-MWCNTs leads to bacteria death. Furthermore, F-SWCNTs were concluded to have less influence on the viability of E. coli because ultra-long F-SWCNTs used in this study performed less rigidity to pierce the cells.

Toxicity mechanism of carbon nanotubes on Escherichia coli

International Nuclear Information System (INIS)

Young, Yu-Fu; Lee, Hui-Ju; Shen, Yi-Shan; Tseng, Shih-Hao; Lee, Chi-Young; Tai, Nyan-Hwa; Chang, Hwan-You

2012-01-01

Highlights: ► F-MWCNTs possess higher antibiotic performance than that of the F-SWCNTs. ► E. coli cells were pierced when incubated with F-MWCNTs and trapped when incubated with F-SWCNTs. ► The rigidity and moment of CNTs play important role on the antibiotic effect. - Abstract: The influences of carbon nanomaterials on bacteria were investigated using three types of dispersed and functionalized carbon nanomaterials (F-CNMs), viz. functionalized carbon nanopowder (F-CNP), functionalized single-walled carbon nanotubes (F-SWCNTs), and functionalized multi-walled carbon nanotubes (F-MWCNTs). F-CNMs with different aspect ratios were used to study the influence of material configuration on the viability of Escherichia coli (E. coli). Although these materials were functionalized to improve their dispersibility, the original morphologies and chemical properties of the materials were maintained. Traditional bacteria quantitative plating analysis was conducted, and the results of which revealed that the F-CNP and the F-SWCNTs showed a less significant effect on the viability of E. coli, while the F-MWCNTs obviously inhibited cell viability. A Fourier transform infrared spectroscopy and a scanning electron microscopy were used to verify the functionalization of the F-CNMs and to examine the interaction of F-CNMs with E. coli, respectively; in addition, we adopted chemiluminescence assays to measure the concentration of adenosine triphosphate (ATP) released from the damaged cells. The results showed that the ATP of the F-MWCNTs sample is two-fold higher than that of the control, indicating direct piercing of E. coli by F-MWCNTs leads to bacteria death. Furthermore, F-SWCNTs were concluded to have less influence on the viability of E. coli because ultra-long F-SWCNTs used in this study performed less rigidity to pierce the cells.

TRIMETHOPRIM-SULFAMETHOXAZOLE RESISTANCE IN SEWAGE ISOLATES OF ESCHERICHIA COLI

Science.gov (United States)

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...

Antibiofilm Effects of Lactobacilli against Ciprofloxacin-Resistant Uropathogenic Escherichia coli strains in Pasteurized Milk

Directory of Open Access Journals (Sweden)

Mahsa Yeganeh

2017-11-01

Full Text Available  Background and Objective: Uropathogenic Escherichia coli-induced urinary tract infections are the most common uropathogenic Escherichia coli etiological agent. In addition, most of biofilms created by these bacteria can be regarded as a serious problem in the food industry. Foodborne diseases have always been considered an emerging public health concern throughout the world. Many outbreaks have been found to be associated with biofilms. Thus, the aim of the present study is to investigate the anti-adhesive effects of lactic acid bacteria against strains of Ciprofloxacin-Resistant Uropathogenic Escherichia coli using microbial techniques in pasteurized milk.Material and Methods: In this study, strains of Lactobacillus plantarum, Lactobacillus casei and Lactobacillus acidophilus were provided from Pasteur Institute of Iran. Twenty strains of Uropathogenic Escherichia coli-Induced Urinary Tract Infections were isolated from patients with urinary tract infection in Shahid Labbafinejad hospital of Iran. Eight strains with ability of biofilm formation were selected for microbial tests. All of these eight strains were resistant to ciprofloxacin. Disk diffusion method was used to assess the susceptibility of all isolates to the ten common antibiotics. Eight samples of Uropathogenic Escherichia coli were inoculated in pasteurized milk. The microtitre plate 100 method was used to detect anti-adhesive activity of lactobacilli supernatant.Results and Conclusion: Results showed that the eight human isolates were resistant to antibiotics. Isolate of number 4 was the most susceptible strains to antibiofilm effects of lactobacilli in the pasteurized milk. The anti-adhesive effects of lactobacilli on Uropathogenic were confirmed in all microbial tests. In this study, Lactobacillus plantarum revealed the highest inhibitory activity against Uropathogenic Escherichia coli 4 strain with inhibition zones of 42 mm. This strain was reported as a proper probiotic

Escherichia coli can be transformed by a liposome-mediated lipofection method.

Science.gov (United States)

Kawata, Yoshikazu; Yano, Shin-ichi; Kojima, Hiroyuki

2003-05-01

Transformation of Escherichia coli is a basic technique for genetic engineering. We used a liposome-mediated lipofection method to transform electrocompetent E. coli cells which has little natural competence of foreign DNA without electroporation treatment, and got transformants with simple and quick treatment by a plasmid or a transposon and transposase complex.

Draft Genome Sequence of Escherichia coli K-12 (ATCC 10798).

Science.gov (United States)

Dimitrova, Daniela; Engelbrecht, Kathleen C; Putonti, Catherine; Koenig, David W; Wolfe, Alan J

2017-07-06

Here, we present the draft genome sequence of Escherichia coli ATCC 10798. E. coli ATCC 10798 is a K-12 strain, one of the most well-studied model microorganisms. The size of the genome was 4,685,496 bp, with a G+C content of 50.70%. This assembly consists of 62 contigs and the F plasmid. Copyright © 2017 Dimitrova et al.

Antibiotic-resistance of Escherichia coli isolates from stored pig slurry

OpenAIRE

Silva, F.F.P.; Santos, M.; Schmidt, Veronica

2008-01-01

The antimicrobial resistance of 96 Escherichia coli strains isolated from a stabilization pond system on a pig-breeding farm was evaluated. Strains were tested for their resistance against 14 antimicrobial using the agar diffusion method. E. coli strains showed resistance to tetracycline (82.3%), nalidixic acid (64%), ampicilin (41%), sulfamethoxazole/trimethoprin (36%), sulfonamide (34%), cloranphenicol (274%), ciprofloxacin (19%), cefaclor (16%), streptomicyn (7.3%), neomicyn (1%), amoxacil...

Metabolic and Transcriptional Response to Cofactor Perturbations in Escherichia coli

DEFF Research Database (Denmark)

Holm, Anders Koefoed; Blank, L.M.; Oldiges, M.

2010-01-01

Metabolic cofactors such as NADH and ATP play important roles in a large number of cellular reactions, and it is of great interest to dissect the role of these cofactors in different aspects of metabolism. Toward this goal, we overexpressed NADH oxidase and the soluble F1-ATPase in Escherichia coli...... of redox and energy metabolism and should help in developing metabolic engineering strategies in E. coli....

Effect of the oyster contaminated in Salmonella typhimurium and Escherichia coli; Efecto del ostion contaminado en Salmonella typhimurium y Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Brena V, M

1992-08-15

In this work the effect of the oyster contaminated in the species of bacteria better studied by its genetic composition these are the Salmonella typhimurium and the Escherichia coli and that its have been starting point for later radiobiological studies in superior organisms. Of this its have arisen two general lines. The research about the genotoxic effect of substances or mixtures in bacteria with the collaboration of the groups of Drosophila and X-ray Fluorescence analysis and on the other hand the study of the low doses of radiation also in bacteria. It is also treated the topic about the genetic effect of aromatic hydrocarbons in different biological systems. (Author)

Cephalosporin-resistant Escherichia coli isolated from farm-workers and pigs in northern Vietnam

DEFF Research Database (Denmark)

Dang, Son T T; Bortolaia, Valeria; Thi, Nhat T

2018-01-01

OBJECTIVE Antimicrobial-resistant bacteria may be transmitted between farm workers and livestock. This study aimed to determine and compare the prevalence and the genetic determinants of cefotaxime-resistant and ESBL-producing Escherichia coli in faecal isolates from workers and pigs at 100 farms...... in northern Vietnam. METHODS Farmers were interviewed about antimicrobial usage in livestock. Escherichia coli isolated on MacConkey agar containing 2 mg/L of cefotaxime (CTX) were tested for susceptibility to different cephalosporins by disk diffusion and screened for occurrence of ESBL-encoding genes by PCR......% in pigs. In 76% of farms, CTX-resistant E. coli were shared by pigs and farm workers. ESBL-producing E. coli were detected from pigs and workers at 66 and 69 farms, respectively. The ESBL phenotype was mainly mediated by CTX-M and to a lesser extent by TEM. Occurrence of blaCTX-M was similar in E. coli...

ANIMAL ENTEROTOXIGENIC ESCHERICHIA COLI

Science.gov (United States)

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

Attaching and effacing Escherichia coli isolates from Danish children: clinical significance and microbiological characteristics

DEFF Research Database (Denmark)

Jensen, C; Ethelberg, S; Olesen, B

2007-01-01

This study describes the prevalence, clinical manifestations and microbiological characteristics of attaching and effacing Escherichia coli isolates, i.e., enteropathogenic E. coli (EPEC) belonging to the classical EPEC serotypes, non-EPEC attaching and effacing E. coli (A/EEC) and verocytotoxin...

Genetic analysis of diaminopimelic acid- and lysine-requiring mutants of Escherichia coli.

Science.gov (United States)

Bukhari, A I; Taylor, A L

1971-03-01

Several diaminopimelic acid (DAP)- and lysine-requiring mutants of Escherichia coli were isolated and studied by genetic, physiological, and biochemical means. The genes concerned with DAP-lysine synthesis map at several different sites on the E. coli chromosome and, therefore, do not constitute a single operon. Three separate loci affecting DAP synthesis are located in the 0 to 2.5 min region of the genetic map. The order of the loci in this region is thr-dapB-pyrA-ara-leu-pan-dapC-tonA-dapD. Two additional DAP genes map in the region between min 47 and 48, with the gene order being gua-dapA-dapE-ctr. The lys locus at min 55 determines the synthesis of the enzyme DAP decarboxylase, which catalyzes the conversion of DAP into lysine. The order of the genes in this region is serA-lysA-thyA.

Anti-Escherichia coli effect of Hibiscus sabdariffa L. in a meat model

Directory of Open Access Journals (Sweden)

Marcelo Pinto PAIM

Full Text Available Abstract Hibiscus sabdariffa L. is used in traditional medicine because of its bioactive properties, such as antioxidant and antibacterial. Escherichia coli is a Gram-negative bacteria and as an indicator of contamination in food. The aim of this work was to evaluate the anti-Escherichia coli effect and the change in pH on the control of aerobic mesophilic microorganisms, using hydroethanolic extract of H. sabdariffa L. in different concentrations in a meat model, verifying its potential as food additive for microbiological stability on ground beef during cooling storage. For the preparation of the treatments, the meat experimental units were elaborated with different concentrations of the vegetal extract (5, 10, 15 and 20%, ground beef and contaminated with E. coli. For pH evaluation, the meat experimental units were added different percentages of hydroethanolic extract. The H. sabdariffa L. antibacterial action reduced two logarithmic levels in practically all treatments. The best pH result was obtained in the meat containing 30% of the extract. The hydroethanolic extracts of Hibiscus sabdariffa L. showed anti-Escherichia coli activity in the presence of refrigerated ground beef. Analyzing the pH results and the count of aerobic mesophilic bacteria, it is possible this extract to be used as a natural food additive.

Prodigiosin - A Multifaceted Escherichia coli Antimicrobial Agent.

Directory of Open Access Journals (Sweden)

Tjaša Danevčič

Full Text Available 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.

Viabilidad de Escherichia coli en presencia de diferentes contaminantes

Directory of Open Access Journals (Sweden)

Antonio Rivera T

2006-04-01

Full Text Available La contaminación en ríos condiciona la presencia de microorganismos adaptados al ecosistema entre ellos a patógenos de importancia en salud pública. Objetivo: Determinar la viabilidad de Escherichia coli en presencia de nitrato de plata, carbonato de amonio, fenol y formaldehído. Materiales y métodos: Se tomaron muestras de agua del río Alseseca, que luego se sembró en medios de cultivo selectivos para enterobacterias, seleccionándose las colonias del género Escherichia, las cuales fueron sembradas en el medio de orientación CHROMagar ECC. Las muestras de E. coli se evaluaron en presencia de nitrato de plata, carbonato de amonio, fenol y formaldehído. Resultados: El grupo experimental presentó viabilidad en presencia de los cuatro compuestos, el grupo control positivo presentó nula viabilidad, la comparación entre los grupos mostró diferencia significativa (p< 0,05. Conclusión: Los aislamientos de E. coli mostraron viabilidad, implicando riesgos para el ecosistemas y la salud, ya que el río Alseseca atraviesa por el municipio de Puebla donde existen núcleos poblacionales importantes.

in Escherichia coli with native cholesterol oxidase expressed

African Journals Online (AJOL)

The structure and bio-activity of an endogenous cholesterol oxidase from Brevibacterium sp. was compared to the same enzyme exogenously expressed in Escherichia coli BL21 (DE3) with and without N- or C-terminal his-tags. The different proteins were purified with affinity and subtractive protocols. The specific activity of ...

Accurate differentiation of Escherichia coli and Shigella serogroups: challenges and strategies

Directory of Open Access Journals (Sweden)

N.K. Devanga Ragupathi

2018-01-01

Full Text Available Shigella spp. and Escherichia coli are closely related; both belong to the family Enterobacteriaceae. Phenotypically, Shigella spp. and E. coli share many common characteristics, yet they have separate entities in epidemiology and clinical disease, which poses a diagnostic challenge. We collated information for the best possible approach to differentiate clinically relevant E. coli from Shigella spp. We found that a molecular approach is required for confirmation. High discriminatory potential is seen with whole genome sequencing analysed for k-mers and single nucleotide polymorphism. Among these, identification using single nucleotide polymorphism is easy to perform and analyse, and it thus appears more promising. Among the nonmolecular methods, matrix-assisted desorption ionization–time of flight mass spectrometry may be applicable when data analysis is assisted with advanced analytic tools. Keywords: 16S rRNA, k-mer, MALDI-TOF MS, single nucleotide polymorphism, whole genome sequencing

Transport proteins promoting Escherichia coli pathogenesis

Science.gov (United States)

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

Transport proteins promoting Escherichia coli pathogenesis.

Science.gov (United States)

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

HUBUNGAN PERSONAL HYGIENE DENGAN KEBERADAAN ESCHERICHIA COLI PADA MAKANAN DI TEMPAT PENGOLAHAN MAKANAN (TPM BUFFER AREA BANDARA ADI SOEMARMO SURAKARTA

Directory of Open Access Journals (Sweden)

Fitka Romanda

2017-01-01

Full Text Available Keberadaan Escherichia coli dalam sumber air atau makanan merupakan indikasi pasti terjadinya  kontaminasi tinja manusia. Kontaminasi ini dapat berdampak pada Kejadian Luar Biasa keracunan makanan di negara berkembang, termasuk di Indonesia. Adanya kontaminasi Escherichia coli pada makanan dapat disebabkan faktor personal hygiene penjamah makanan yang kurang baik. Penelitian ini bertujuan untuk mengetahui adanya hubungan personal hygiene penjamah makanan dengan Escherichia coli. Penelitian ini menggunakan metode observasional dengan pendekatan cross sectional. Subyek penelitian adalah 65 penjamah makanan dan 65 sampel makanan di 22 tempat pengolahan makanan buffer area Bandara Adi Soemarmo Surakarta. Hasil penelitian menunjukan adanya hubungan personal hygiene dengan keberadaan Escherichia coli pada makanan di Tempat Pengolahan Makanan Buffer Area Bandara Adi Soemarmo Surakarta dengan uji statistik dengan Chi Square didapatkan p value (0,000 dan kekuatan hubungan sedang dengan nilai C (0,477. Berdasarkan hasil penelitian, disimpulkan terdapat hubungan personal hygiene penjamah makanan dengan keberadaan Escherichia coli pada makanan di tempat pengolahan makanan (TPM buffer area Bandara Adi Soemarmo Surakarta.   Kata kunci. Personal Hygiene, Escherichia coli, Buffer Area

Genome Sequences of Two Copper-Resistant Escherichia coli Strains Isolated from Copper-Fed Pigs

DEFF Research Database (Denmark)

Lüthje, Freja L.; Hasman, Henrik; Aarestrup, Frank Møller

2014-01-01

The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances.......The draft genome sequences of two copper-resistant Escherichia coli strains were determined. These had been isolated from copper-fed pigs and contained additional putative operons conferring copper and other metal and metalloid resistances....

Biomolecular Mechanisms of Pseudomonas aeruginosa and Escherichia coli Biofilm Formation

Science.gov (United States)

Laverty, Garry; Gorman, Sean P.; Gilmore, Brendan F.

2014-01-01

Pseudomonas aeruginosa and Escherichia coli are the most prevalent Gram-negative biofilm forming medical device associated pathogens, particularly with respect to catheter associated urinary tract infections. In a similar manner to Gram-positive bacteria, Gram-negative biofilm formation is fundamentally determined by a series of steps outlined more fully in this review, namely adhesion, cellular aggregation, and the production of an extracellular polymeric matrix. More specifically this review will explore the biosynthesis and role of pili and flagella in Gram-negative adhesion and accumulation on surfaces in Pseudomonas aeruginosa and Escherichia coli. The process of biofilm maturation is compared and contrasted in both species, namely the production of the exopolysaccharides via the polysaccharide synthesis locus (Psl), pellicle Formation (Pel) and alginic acid synthesis in Pseudomonas aeruginosa, and UDP-4-amino-4-deoxy-l-arabinose and colonic acid synthesis in Escherichia coli. An emphasis is placed on the importance of the LuxR homologue sdiA; the luxS/autoinducer-II; an autoinducer-III/epinephrine/norepinephrine and indole mediated Quorum sensing systems in enabling Gram-negative bacteria to adapt to their environments. The majority of Gram-negative biofilms consist of polysaccharides of a simple sugar structure (either homo- or heteropolysaccharides) that provide an optimum environment for the survival and maturation of bacteria, allowing them to display increased resistance to antibiotics and predation. PMID:25438014

Biomolecular Mechanisms of Pseudomonas aeruginosa and Escherichia coli Biofilm Formation

Directory of Open Access Journals (Sweden)

Garry Laverty

2014-07-01

Full Text Available Pseudomonas aeruginosa and Escherichia coli are the most prevalent Gram-negative biofilm forming medical device associated pathogens, particularly with respect to catheter associated urinary tract infections. In a similar manner to Gram-positive bacteria, Gram-negative biofilm formation is fundamentally determined by a series of steps outlined more fully in this review, namely adhesion, cellular aggregation, and the production of an extracellular polymeric matrix. More specifically this review will explore the biosynthesis and role of pili and flagella in Gram-negative adhesion and accumulation on surfaces in Pseudomonas aeruginosa and Escherichia coli. The process of biofilm maturation is compared and contrasted in both species, namely the production of the exopolysaccharides via the polysaccharide synthesis locus (Psl, pellicle Formation (Pel and alginic acid synthesis in Pseudomonas aeruginosa, and UDP-4-amino-4-deoxy-l-arabinose and colonic acid synthesis in Escherichia coli. An emphasis is placed on the importance of the LuxR homologue sdiA; the luxS/autoinducer-II; an autoinducer-III/epinephrine/norepinephrine and indole mediated Quorum sensing systems in enabling Gram-negative bacteria to adapt to their environments. The majority of Gram-negative biofilms consist of polysaccharides of a simple sugar structure (either homo- or heteropolysaccharides that provide an optimum environment for the survival and maturation of bacteria, allowing them to display increased resistance to antibiotics and predation.

Genomic Variability of O Islands Encoding Tellurite Resistance in Enterohemorrhagic Escherichia coli O157:H7 Isolates

OpenAIRE

Taylor, Diane E.; Rooker, Michelle; Keelan, Monika; Ng, Lai-King; Martin, Irene; Perna, Nicole T.; Burland, N. T. Valerie; Blattner, Fredrick R.

2002-01-01

Strains of Escherichia coli causing enterohemorrhagic colitis belonging to the O157:H7 lineage are reported to be highly related. Fifteen strains of E. coli O157:H7 and 1 strain of E. coli O46:H− (nonflagellated) were examined for the presence of potassium tellurite resistance (Ter). Ter genes comprising terABCDEF were shown previously to be part of a pathogenicity island also containing integrase, phage, and urease genes. PCR analysis, both conventional and light cycler based, demonstrated t...

Effect of visible range electromagnetic radiations on Escherichia coli ...

African Journals Online (AJOL)

Background: Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of ...

Expression and purification of recombinant hemoglobin in Escherichia coli

DEFF Research Database (Denmark)

Natarajan, Chandrasekhar; Jiang, Xiaoben; Fago, Angela

2011-01-01

BACKGROUND: Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb) and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe...

Inactivation of Escherichia coli by titanium dioxide photocatalytic oxidation.

Science.gov (United States)

Titanium dioxide in the anatase crystalline form was used as a photocatalyst to generate hydroxyl radicals in a flowthrough water reactor. Experiments were performed on pure cultures of Escherichia coli in dechlorinated tap water and a surface water sample to evaluate the disinfe...

PCR approach for rapid detection of Escherichia coli in tempe using a specific primer

Directory of Open Access Journals (Sweden)

Siti Harnina Bintari

2014-12-01

Full Text Available Tempe known as a traditional fermented food originated from Indonesia. It has a unique flavour and texture. It also contains high protein and usually serves to substitute meat, fish, or egg as a complement to rice. The manufacture process of Tempe is quite complex and mostly, the traditional process has not employed the hygienic standard. In the process of Tempe making, there are two critical stages of the whole process; i.e. soaking of soybeans and solid state fermentation by Rhizopus sp. During the process, foodborne pathogen bacteria such as Escherichia coli could contaminate the product of Tempe. The bacterial contamination could be revealed through culture dependent methods which is costly, laborious, and time consuming. Therefore, the culture-independent method such as polymerase chain reaction using a specific primer could be applied to detect target microorganism to save time and labour. In this study, thirty-one Tempe samples collected from different manufacturers in Semarang, Central Java, Indonesia were analysed by PCR. In order to obtain the bacterial genomic DNA, a modified Chelex 100-Microwave method was employed. The results of DNA extraction showed that the method was an applicable method. It gave high quantity and quality of DNA; therefore, it could be applied in the PCR reaction. The DNA samples were employed in PCR for detection of Escherichia coli using Ecoli706F/R. It was found that 27 out of 31 samples were detected having Escherichia coli contamination showed by the presence of the amplified product size 706 bp. The application of this method could significantly reduce costs and time of analysis in the laboratory. Further response after E. coli were detected could be employed, including investigation of the critical factors in Tempe manufacturing process which allowed E. coli contamination.

Global impact of mature biofilm lifestyle on Escherichia coli K-12 gene expression

DEFF Research Database (Denmark)

Beloin, C.; Valle, J.; Latour-Lambert, P.

2004-01-01

The formation of biofilm results in a major lifestyle switch that is thought to affect the expression of multiple genes and operons. We used DNA arrays to study the global effect of biofilm formation on gene expression in mature Escherichia coli K-12 biofilm. We show that, when biofilm is compared...... that 20 of these genes are required for the formation of mature biofilm. This group includes 11 genes of previously unknown function. These results constitute a comprehensive analysis of the global transcriptional response triggered in mature E. coli biofilms and provide insights into its physiological...

Comparative proteomic analysis of proteins expression changes in the mammary tissue of cows infected with Escherichia coli mastitis.

Science.gov (United States)

Zhao, Xiao-wei; Yang, Yong-xin; Huang, Dong-wei; Cheng, Guang-long; Zhao, Hui-ling

2015-01-01

Cows infected with Escherichia (E.) coli usually experience severe clinical symptoms, including damage to mammary tissues, reduced milk yield, and altered milk composition. In order to investigate the host response to E. coli infection and discover novel markers for mastitis treatment, mammary tissue samples were collected from healthy cows and bovines with naturally occurring severe E. coli mastitis. Changes of mammary tissue proteins were examined using two-dimensional gel electrophoresis and label-free proteomic approaches. A total of 95 differentially expressed proteins were identified. Of these, 56 proteins were categorized according to molecular function, cellular component, and biological processes. The most frequent biological processes influenced by the proteins were response to stress, transport, and establishment of localization. Furthermore, a network analysis of the proteins with altered expression in mammary tissues demonstrated that these factors are predominantly involved with binding and structural molecule activities. Vimentin and a-enolase were central "functional hubs" in the network. Based on results from the present study, disease-induced alterations of protein expression in mammary glands and potential markers for the effective treatment of E. coli mastitis were identified. These data have also helped elucidate defense mechanisms that protect the mammary glands and promote the pathogenesis of E. coli mastitis.

Effect of enrofloxacin treatment on plasma endotoxin during bovine Escherichia coli mastitis

NARCIS (Netherlands)

Dosogne, H.; Meyer, E.; Sturk, A.; van Loon, J.; Massart-Leën, A. M.; Burvenich, C.

2002-01-01

OBJECTIVE AND DESIGN: To investigate the effect of enrofloxacin on endotoxin resorption during bovine Escherichia coli mastitis. ANIMALS: 12 healthy early post partum Holstein cows. TREATMENT: Mastitis was induced by intramammary infusion of 10(4) cfu E. coli P4:032. Six cows were treated twice

Urothelial CD44 facilitates Escherichia coli infection of the murine urinary tract

NARCIS (Netherlands)

Rouschop, Kasper M. A.; Sylva, Marc; Teske, Gwendoline J. D.; Hoedemaeker, Inge; Pals, Steven T.; Weening, Jan J.; van der Poll, Tom; Florquin, Sandrine

2006-01-01

Escherichia coli is the most common pathogen found in urinary tract infections (UTIs), mainly affecting children and women. We report that CD44, a hyaluronic acid (HA) binding protein that mediates cell-cell and cell-matrix interactions, facilitates the interaction of E. coli with urothelial cells

Sos - response induction by gamma radiation in Escherichia coli strains with different repair capacities

International Nuclear Information System (INIS)

Serment Guerrero, J.H.

1992-01-01

The Sos - response in Escherichia coli is formed by several genes involved in mechanisms of tolerance and/or repair, and only activates when a DNA - damage appears. It is controlled by recA and lexA genes. In normal circumstances, LexA protein is linked in every Sos operators, blocking the transcription. When a DNA damage occurs, a Sos signal is generated, Rec A protein changes its normal functions, starts acting as a protease and cleaves Lex A, allowing the transcription of all Sos genes. This response can be quantified by means of Sos Chromo test, performed by Quillardet and Ofnung (1985). In using the Chromo test, it has been observed that the DNA damage made by gamma radiation in Escherichia coli depends on both the doses and the doses rate. It has been shown that the exposure of Escherichia coli PQ37 strain (uvrA) to low doses at low dose rate appears to retard the response, suggesting the action of a repair mechanism. (Brena 1990). In this work, we compare the response in Escherichia coli strains deficient in different mechanisms of repair and/or tolerance. It is observed the importance of rec N gene in the repair of DNA damage produced by gamma radiation. (Author)

Comparative analysis of antibiotic resistance and phylogenetic group patterns in human and porcine urinary tract infectious Escherichia coli

DEFF Research Database (Denmark)

Hancock, Viktoria; Nielsen, E.M.; Krag, L.

2009-01-01

Urinary tract infections (UTIs) are one of the most common infectious diseases in humans and domestic animals such as pigs. The most frequent infectious agent in such infections is Escherichia coli. Virulence characteristics of E. coli UTI strains range from highly virulent pyelonephritis strains...... to relatively benign asymptomatic bacteriuria strains. Here we analyse a spectrum of porcine and human UTI E. coli strains with respect to their antibiotic resistance patterns and their phylogenetic groups, determined by multiplex PCR. The clonal profiles of the strains differed profoundly; whereas human...

Inactivation of Escherichia coli in soil by solarization

International Nuclear Information System (INIS)

Wu, S.; Nishihara, M.; Kawasaki, Y.; Yokoyama, A.; Matsuura, K.; Koga, T.; Ueno, D.; Inoue, K.; Someya, T.

2009-01-01

Contamination of agricultural soil by fecal pathogenic bacteria poses a potential risk of infection to humans. For the biosafety control of field soil, soil solarization in an upland field was examined to determine the efficiency of solarization on the inactivation of Escherichia coli inoculated into soil as a model microorganism for human pathogenic bacteria. Soil solarization, carried out by sprinkling water and covering the soil surface with thin plastic sheets, greatly increased the soil temperature. The daily average temperature of the solarized soil was 4–10°C higher than that of the non-solarized soil and fluctuated between 31 and 38°C. The daily highest temperature reached more than 40°C for 8 days in total in the solarized soil during the second and third weeks of the experiment. Escherichia coli in the solarized soil became undetectable (< 0.08 c.f.u. g −1 dry soil) within 4 weeks as a result, whereas E. coli survived for more than 6 weeks in the non-solarized soil. Soil solarization, however, had little influence on the total direct count and total viable count of bacteria in the soil. These results indicate that soil solarization would be useful for the biosafety control of soil contaminated by human pathogens via immature compost or animal feces. (author)

The asymptomatic bacteriuria Escherichia coli strain 83972 outcompetes uropathogenic E. coli strains in human urine

DEFF Research Database (Denmark)

Hancock, Viktoria; Ulett, G.C.; Schembri, M.A.

2006-01-01

Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infections (UTI), very little is known about the mechanisms by which these strains colonize the human urinary tract....... The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. Deliberate colonization of UTI-susceptible individuals with E. coli 83972 has been used successfully as an alternative approach for the treatment of patients who are refractory...... to conventional therapy. Colonization with strain 83972 appears to prevent infection with UPEC strains in such patients despite the fact that this strain is unable to express the primary adhesins involved in UTI, viz. P and type 1 fimbriae. Here we investigated the growth characteristics of E. coli 83972 in human...

Protein disulfide bond generation in Escherichia coli DsbB–DsbA

International Nuclear Information System (INIS)

Inaba, Kenji

2008-01-01

The crystal structure of the DsbB–DsbA–ubiquinone ternary complex has revealed a mechanism of protein disulfide bond generation in Escherichia coli. Protein disulfide bond formation is catalyzed by a series of Dsb enzymes present in the periplasm of Escherichia coli. The crystal structure of the DsbB–DsbA–ubiquinone ternary complex provided important insights into mechanisms of the de novo disulfide bond generation cooperated by DsbB and ubiquinone and of the disulfide bond shuttle from DsbB to DsbA. The structural basis for prevention of the crosstalk between the DsbA–DsbB oxidative and the DsbC–DsbD reductive pathways has also been proposed

Epidemiology of 3rd generation cephalosporin-resistant Escherichia coli on dairy farms

Science.gov (United States)

Dairy cattle have been identified as a reservoir for 3rd generation cephalosporin (3GC)-resistant Escherichia coli. We previously identified 3GC-resistant E. coli from manure composite samples of calves and cows in a survey of 80 farms in Pennsylvania. Resistant strains were most frequently isolated...

UV irradiation alters deoxynucleoside triphosphate pools in Escherichia coli

International Nuclear Information System (INIS)

Das, S.K.; Loeb, L.A.

1984-01-01

UV irradiation of exponentially growing Escherichia coli increased intracellular concentration of dATP and dTTP without significantly changing the concentrations of dGTP and dCTP. These selective increases in dATP and dTTP pools are seen in wild-type E. coli K12 and AB1157, as well as in recA and umuC strains, and are proportional to UV dose. The possible significance of these findings with respect to induction of the SOS response and nontargeted mutagenesis are discussed. (orig.)

Application of dynamic flux balance analysis to an industrial Escherichia coli fermentation.

Science.gov (United States)

Meadows, Adam L; Karnik, Rahi; Lam, Harry; Forestell, Sean; Snedecor, Brad

2010-03-01

We have developed a reactor-scale model of Escherichia coli metabolism and growth in a 1000 L process for the production of a recombinant therapeutic protein. The model consists of two distinct parts: (1) a dynamic, process specific portion that describes the time evolution of 37 process variables of relevance and (2) a flux balance based, 123-reaction metabolic model of E. coli metabolism. This model combines several previously reported modeling approaches including a growth rate-dependent biomass composition, maximum growth rate objective function, and dynamic flux balancing. In addition, we introduce concentration-dependent boundary conditions of transport fluxes, dynamic maintenance demands, and a state-dependent cellular objective. This formulation was able to describe specific runs with high-fidelity over process conditions including rich media, simultaneous acetate and glucose consumption, glucose minimal media, and phosphate depleted media. Furthermore, the model accurately describes the effect of process perturbations--such as glucose overbatching and insufficient aeration--on growth, metabolism, and titer. (c) 2009 Elsevier Inc. All rights reserved.

Current pathogenic Escherichia coli foodborne outbreak cases and therapy development.

Science.gov (United States)

Yang, Shih-Chun; Lin, Chih-Hung; Aljuffali, Ibrahim A; Fang, Jia-You

2017-08-01

Food contamination by pathogenic microorganisms has been a serious public health problem and a cause of huge economic losses worldwide. Foodborne pathogenic Escherichia coli (E. coli) contamination, such as that with E. coli O157 and O104, is very common, even in developed countries. Bacterial contamination may occur during any of the steps in the farm-to-table continuum from environmental, animal, or human sources and cause foodborne illness. To understand the causes of the foodborne outbreaks by E. coli and food-contamination prevention measures, we collected and investigated the past 10 years' worldwide reports of foodborne E. coli contamination cases. In the first half of this review article, we introduce the infection and symptoms of five major foodborne diarrheagenic E. coli pathotypes: enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli/enterohemorrhagic E. coli (STEC/EHEC), Shigella/enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), and enterotoxigenic E. coli (ETEC). In the second half of this review article, we introduce the foodborne outbreak cases caused by E. coli in natural foods and food products. Finally, we discuss current developments that can be applied to control and prevent bacterial food contamination.

Characterization, Genome Sequence, and Analysis of Escherichia Phage CICC 80001, a Bacteriophage Infecting an Efficient L-Aspartic Acid Producing Escherichia coli.

Science.gov (United States)

Xu, Youqiang; Ma, Yuyue; Yao, Su; Jiang, Zengyan; Pei, Jiangsen; Cheng, Chi

2016-03-01

Escherichia phage CICC 80001 was isolated from the bacteriophage contaminated medium of an Escherichia coli strain HY-05C (CICC 11022S) which could produce L-aspartic acid. The phage had a head diameter of 45-50 nm and a tail of about 10 nm. The one-step growth curve showed a latent period of 10 min and a rise period of about 20 min. The average burst size was about 198 phage particles per infected cell. Tests were conducted on the plaques, multiplicity of infection, and host range. The genome of CICC 80001 was sequenced with a length of 38,810 bp, and annotated. The key proteins leading to host-cell lysis were phylogenetically analyzed. One protein belonged to class II holin, and the other two belonged to the endopeptidase family and N-acetylmuramoyl-L-alanine amidase family, respectively. The genome showed the sequence identity of 82.7% with that of Enterobacteria phage T7, and carried ten unique open reading frames. The bacteriophage resistant E. coli strain designated CICC 11021S was breeding and its L-aspartase activity was 84.4% of that of CICC 11022S.

Impact of antibiotic restriction on resistance levels of Escherichia coli

DEFF Research Database (Denmark)

Boel, Jonas; Andreasen, Viggo; Jarløv, Jens Otto

2016-01-01

as a retrospective controlled interrupted time series (ITS) at two university teaching hospitals, intervention and control, with 736 and 552 beds, respectively. The study period was between January 2008 and September 2014. We used ITS analysis to determine significant changes in antibiotic use and resistance levels......% CI -177, -126)] and fluoroquinolones [-44.5 DDDs/1000 bed-days (95% CI -58.9, -30.1)]. Resistance of E. coli showed a significant change in slope for cefuroxime [-0.13 percentage points/month (95% CI -0.21, -0.057)] and ciprofloxacin [-0.15 percentage points/month (95% CI -0.26, -0.038)]. CONCLUSIONS......OBJECTIVES: We evaluated the effect of an antibiotic stewardship programme (ASP) on the use of antibiotics and resistance levels of Escherichia coli using a method that allowed direct comparison between an intervention hospital and a control hospital. METHODS: The study was conducted...

Increasing the permeability of Escherichia coli using MAC13243

DEFF Research Database (Denmark)

Muheim, Claudio; Götzke, Hansjörg; Eriksson, Anna U.

2017-01-01

molecules that make the outer membrane of Escherichia coli more permeable. We identified MAC13243, an inhibitor of the periplasmic chaperone LolA that traffics lipoproteins from the inner to the outer membrane. We observed that cells were (1) more permeable to the fluorescent probe 1-N...

Relationship among fecal coliforms, Escherichia coli, and Salmonella spp. in shellfish.

Science.gov (United States)

Hood, M A; Ness, G E; Blake, N J

1983-01-01

The relationship of fecal coliforms, Escherichia coli, and Salmonella spp. was examined in freshly harvested and stored shellfish. In 16 of 40 freshly collected oyster samples, fecal coliform levels were above the recommended wholesale level suggested by the National Shellfish Sanitation Program (less than or equal to 230/100 g), and Salmonella spp. were present in three of these samples. Salmonella spp. were not, however, present in any sample containing less than 230 fecal coliforms per 100 g. Analysis of the data suggests that low fecal coliform levels in both fresh and stored oysters are good indicators of the absence of Salmonella spp., but that high levels of fecal coliforms are somewhat limited in predicting the presence of Salmonella spp. E. coli levels correlated very strongly with fecal coliform levels in both fresh and stored oysters and clams, suggesting that there is no advantage in replacing fecal coliforms with E. coli as an indicator of shellfish quality.

Impact of cranberry on Escherichia coli cellular surface characteristics

International Nuclear Information System (INIS)

Johnson, Brandy J.; Lin Baochuan; Dinderman, Michael A.; Rubin, Robert A.; Malanoski, Anthony P.; Ligler, Frances S.

2008-01-01

The anti-adhesive effects of cranberry have been attributed to both interactions of its components with the surface of bacterial cells and to inhibition of p-fimbriae expression. Previous reports also suggested that the presence of cranberry juice changed the Gram stain characteristics of Escherichia coli. Here, we show that the morphology of E. coli is changed when grown in the presence of juice or extract from Vaccinium macrocarpon (cranberry). Gene expression analysis indicates the down regulation of flagellar basal body rod and motor proteins. Consistent with this finding and previous reports, the SEM images indicate a decrease in the visible p-fimbriae. The iodine used in Gram-staining protocols was found to interact differently with the bacterial membrane when cells were cultured in spiked media. Slight alterations in the Gram stain protocol demonstrated that culturing in the presence of cranberry juice does not change the Gram stain characteristics contradicting other reports.

Escherichia coli O26 IN RAW BUFFALO MILK: PRELIMINARY RESULTS

Directory of Open Access Journals (Sweden)

A. Rella

2013-02-01

Full Text Available Escherichia coli O26 is considered to be one of the most important food-borne pathogen. In this study, 120 buffalo milk samples collected in Lazio and in Apulia regions were tested for the presence of E. coli O26. One buffalo milk sample (0,8% tested positive for E. coli O26; the isolate was positive at the verocytotoxicity test and it showed resistance properties to different antimicrobial classes. These preliminary results highlight the need to monitor the foods of animal origin used for production and eaten by a wide range of persons, respect VTEC organism.

Cloning, purification, crystallization and preliminary crystallographic analysis of LsrR from Escherichia coli

International Nuclear Information System (INIS)

Liu, Xiaotian; Wu, Minhao; Sun, Demeng; Zang, Jianye

2010-01-01

The E. coli transcription repressor LsrR has been overexpressed, purified and crystallized. Diffraction data were collected to about 3 Å resolution. In Escherichia coli, the lsr operon is composed of six genes lsrACDBFG which regulate uptake and modification of the signalling molecule AI-2. LsrR is a repressor of the lsr operon and itself, which can bind phospho-AI-2 and be released from the promoter region of the operon and thus activate gene expression. LsrR fused with an HHHHHH sequence at the C-terminus was expressed, purified and crystallized in order to determine its structure and elucidate the molecular mechanism of repression. The crystal belonged to space group I222, with unit-cell parameters a = 79.84, b = 116.65, c = 186.04 Å, and was estimated to contain two protein molecules per asymmetric unit

Cloning and expression of the Legionella micdadei "common antigen" in Escherichia coli

DEFF Research Database (Denmark)

Bangsborg, Jette Marie; Collins, M T; Høiby, N

1989-01-01

To study individual Legionella antigens, a Legionella micdadei genomic library in Escherichia coli SC181 was established. Partially Sau3A digested L. micdadei DNA fragments (15-25 kilobase pairs (kb] were cloned into the tetracycline resistance gene of the cosmid vector pHC79. Four thousand...... ampicillin resistant recombinants were obtained; seven hundred were screened for expression of Legionella antigens in Western blot analysis with a polyspecific E. coli-absorbed anti-L. micdadei rabbit antibody. One of the positive clones expressed a 60 kilodalton (K) antigen, which reacted strongly...... will provide important information with respect to genetic vs. antigenic relatedness among Legionellae and other Gram-negative species, as well as to CA structure and possible function....

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

NARCIS (Netherlands)

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

2016-01-01

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.

Resistant plasmid profile analysis of multidrug resistant Escherichia ...

African Journals Online (AJOL)

Background: Multi-drug resistant Escherichia coli has become a major threat and cause of many urinary tract infections (UTIs) in Abeokuta, Nigeria. Objectives: This study was carried out to determine the resistant plasmids of multidrug resistant Escherichia coli isolated from (Urinary tract infections)UTIs in Abeokuta.

Systems Biology Approach to Bioremediation of Nitroaromatics: Constraint-Based Analysis of 2,4,6-Trinitrotoluene Biotransformation by Escherichia coli

Directory of Open Access Journals (Sweden)

Maryam Iman

2017-08-01

Full Text Available Microbial remediation of nitroaromatic compounds (NACs is a promising environmentally friendly and cost-effective approach to the removal of these life-threating agents. Escherichia coli (E. coli has shown remarkable capability for the biotransformation of 2,4,6-trinitro-toluene (TNT. Efforts to develop E. coli as an efficient TNT degrading biocatalyst will benefit from holistic flux-level description of interactions between multiple TNT transforming pathways operating in the strain. To gain such an insight, we extended the genome-scale constraint-based model of E. coli to account for a curated version of major TNT transformation pathways known or evidently hypothesized to be active in E. coli in present of TNT. Using constraint-based analysis (CBA methods, we then performed several series of in silico experiments to elucidate the contribution of these pathways individually or in combination to the E. coli TNT transformation capacity. Results of our analyses were validated by replicating several experimentally observed TNT degradation phenotypes in E. coli cultures. We further used the extended model to explore the influence of process parameters, including aeration regime, TNT concentration, cell density, and carbon source on TNT degradation efficiency. We also conducted an in silico metabolic engineering study to design a series of E. coli mutants capable of degrading TNT at higher yield compared with the wild-type strain. Our study, therefore, extends the application of CBA to bioremediation of nitroaromatics and demonstrates the usefulness of this approach to inform bioremediation research.

Temporal stability of Escherichia coli concentration patterns in two irrigation ponds in Maryland

Science.gov (United States)

Fecal contamination of water sources is an important water quality issue for agricultural irrigation ponds. Escherichia coli is a common microbial indicator used to evaluate recreational and irrigation water quality. We hypothesized that there is a temporally stable pattern of E.coli concentrations ...

Influence of bromouracil density labelling on viability of UV irradiated Escherichia coli cells

Energy Technology Data Exchange (ETDEWEB)

Brozmanova, J [Slovenska Akademia Vied, Bratislava (Czechoslovakia). Vyskumny Ustav Onkologicky

1976-01-01

Influence of 5-bromouracil cultivation on cell viability and DNA synthesis in the Escherichia coli B/r thy/sup -/ trp/sup -/ Hcr/sup +/ and Escherichia coli C thy-321 strains was followed. It was found that a 120 min cultivation in the bromouracil medium (unirradiated cells) does not essentially influence the viability of the two investigated strains but has an inhibitory effect on DNA synthesis in cells of the E. coli B/r Hcr/sup +/ strain. However, cultivation with bromouracil after ultraviolet irradiation leads to a decreased surviving ability of the irradiated cells of both investigated strains. Repair of damage induced by ultraviolet radiation probably exhausts a considerable proportion of repair activity, so that additional injury produced by bromouracil cultivation cannot be liquidated immediately.

Lon gene and photoprotection in Escherichia coli K-12

Energy Technology Data Exchange (ETDEWEB)

Waksman, G.; Thomas, G.; Favre, A. (Institut de Recherche en Biologie Moleculaire, Group de Photobiologie Moleculaire, Paris (France))

1984-03-01

Photoprotection, i.e. the increased resistance of the cells preilluminated with near ultraviolet light (300-380 nm) to the lethal action of 254nm radiations requires either an integrated prophage or a recA mutation in Escherichia coli K12 strains. Significant photoprotection occurs in an Escherichia coli K12 recA/sup +/ cell containing the lon allele responsible for filamentous growth after 254nm irradiation. The Fil phenotype can be suppressed by the sfiA or sfiB suppressor genes. Since the E. coli K12 recA/sup +/ lon sfiB strain exhibits no more photoprotection, it is concluded that in lon strains photoprotection is due to the abolition of the 254nm induced filamentation by the near ultraviolet treatment. In addition, near ultraviolet illumination of the cells leads to a severe restriction of the bulk protein synthesis. This effect is observed only in nuv/sup +/ cells that contain 4-thiouridine the chromophore responsible for photoprotection. It is proposed that in lon (lysogenic strains) photoprotection is due to prevention of the SOS response. During the growth lag, the low residual level of protein synthesis does not allow the induction of the SOS response and accordingly prevents filamentation (the lytic cycle).

Multiple Antimicrobial Resistance of Escherichia coli Isolated from Chickens in Iran.

Science.gov (United States)

Talebiyan, Reza; Kheradmand, Mehdi; Khamesipour, Faham; Rabiee-Faradonbeh, Mohammad

2014-01-01

Antimicrobial agents are used extremely in order to reduce the great losses caused by Escherichia coli infections in poultry industry. In this study, 318 pathogenic Escherichia coli (APEC) strains isolated from commercial broiler flocks with coli-septicemia were examined for antimicrobials of both veterinary and human significance by disc diffusion method. Multiple resistances to antimicrobial agents were observed in all the isolates. Resistance to the antibiotics was as follows: Tylosin (88.68%), Erythromycin (71.70%), Oxytetracycline (43.40%), Sulfadimethoxine-Trimethoprim (39.62%), Enrofloxacin (37.74%), Florfenicol (35.85%), Chlortetracycline (33.96%), Doxycycline (16.98%), Difloxacin (32.08%), Danofloxacin (28.30%), Chloramphenicol (20.75%), Ciprofloxacin (7.55%), and Gentamicin (5.66%). This study showed resistance against the antimicrobial agents that are commonly applied in poultry, although resistance against the antibiotics that are only applied in humans or less frequently used in poultry was significantly low. This study emphasizes on the occurrence of multiple drug resistant E. coli among diseased broiler chickens in Iran. The data revealed the relative risks of using antimicrobials in poultry industry. It also concluded that use of antibiotics must be limited in poultry farms in order to reduce the antibiotic resistances.

Multiple Antimicrobial Resistance of Escherichia coli Isolated from Chickens in Iran

Directory of Open Access Journals (Sweden)

Reza Talebiyan

2014-01-01

Full Text Available Antimicrobial agents are used extremely in order to reduce the great losses caused by Escherichia coli infections in poultry industry. In this study, 318 pathogenic Escherichia coli (APEC strains isolated from commercial broiler flocks with coli-septicemia were examined for antimicrobials of both veterinary and human significance by disc diffusion method. Multiple resistances to antimicrobial agents were observed in all the isolates. Resistance to the antibiotics was as follows: Tylosin (88.68%, Erythromycin (71.70%, Oxytetracycline (43.40%, Sulfadimethoxine-Trimethoprim (39.62%, Enrofloxacin (37.74%, Florfenicol (35.85%, Chlortetracycline (33.96%, Doxycycline (16.98%, Difloxacin (32.08%, Danofloxacin (28.30%, Chloramphenicol (20.75%, Ciprofloxacin (7.55%, and Gentamicin (5.66%. This study showed resistance against the antimicrobial agents that are commonly applied in poultry, although resistance against the antibiotics that are only applied in humans or less frequently used in poultry was significantly low. This study emphasizes on the occurrence of multiple drug resistant E. coli among diseased broiler chickens in Iran. The data revealed the relative risks of using antimicrobials in poultry industry. It also concluded that use of antibiotics must be limited in poultry farms in order to reduce the antibiotic resistances.

Energetics of sodium efflux from Escherichia coli

International Nuclear Information System (INIS)

Borbolla, M.G.; Rosen, B.P.

1984-01-01

When energy-starved cells of Escherichia coli were passively loaded with 22 Na+, efflux of sodium could be initiated by addition of a source of metabolic energy. Conditions were established where the source of energy was phosphate bond energy, an electrochemical proton gradient, or both. Only an electrochemical proton gradient was required for efflux from intact cells. These results are consistent with secondary exchange of Na+ for H+ catalyzed by a sodium/proton antiporter

Antibiotic resistance profile of Escherichia coli isolated from five ...

African Journals Online (AJOL)

Information on the resistance profiles of clinical and non clinical human bacteria isolates in the developing countries can serve as important means of understanding the human pathogens drug resistance interactions in the zone. Escherichia coli isolated from five geopolitical zones of Nigeria were screened for anti-microbial ...

Occurrence of Escherichia coli in Brassica rapa L. chinensis ...

African Journals Online (AJOL)

Low quality water has become valuable resource with restricted or unrestricted use in food production depending on its quality. This study has quantified the occurrence of Escherichia coli in Brassica rapa L. chinensis (Chinese cabbage) vegetables and low quality irrigation water. A total of 106 samples including Chinese ...

Prevalence of Escherichia coli virulence genes in patients with ...

African Journals Online (AJOL)

In this study, we investigated the prevalence of the virulence genes specific for five major pathogroups of diarrheagenic Escherichia coli (DEC) in primary cultures from diarrhoeagenic patients in Burkina Faso. Methodology: From September 2016 to Mars 2017, a total of 211 faecal samples from diarrhoeagenic patients from ...

THE WIDESPREAD OCCURRENCE OF THE ENTEROHEMOLYSIN GENE EHLYA AMONG ENVIRONMENTAL STRAINS OF ESCHERICHIA COLI

Science.gov (United States)

The putative virulence factor enterohemolysin, encoded for by the ehlyA gene, has been closely associated with the pathogenic enterohemorrhagic Escherichia coli (EHEC) group. E. coli isolates from effluents from seven geographically dispersed municipal ...

Screening for virulence genes in Escherichia coli O157:H7 obtained ...

African Journals Online (AJOL)

Eighty (80) sources of drinking water comprising boreholes (24), streams (3), wells (29), pipe-borne (5) and 19 sachet water samples were collected between March 2014 and February 2015. Escherichia coli (E.coli) O157:H7 was isolated by enrichment in Tryptone soy broth at elevated temperature and streaking on Eosin ...

beta-Chloro-L-alanine inhibition of the Escherichia coli alanine-valine transaminase.

OpenAIRE

Whalen, W A; Wang, M D; Berg, C M

1985-01-01

beta-Chloro-L-alanine, an amino acid analog which inhibits a number of enzymes, reversibly inhibited the Escherichia coli K-12 alanine-valine transaminase, transaminase C. This inhibition, along with the inhibition of transaminase B, accounted for the isoleucine-plus-valine requirement of E. coli in the presence of beta-chloro-L-alanine.

Formate detection by potassium permanganate for enhanced hydrogen production in Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Maeda, Toshinari [Artie McFerrin Department of Chemical Engineering, 220 Jack E. Brown Building, Texas A and M University, College Station, TX 77843-3122 (United States); Wood, Thomas K. [Artie McFerrin Department of Chemical Engineering, 220 Jack E. Brown Building, Texas A and M University, College Station, TX 77843-3122 (United States); Department of Biology, Texas A and M University, College Station, TX 77843-3258 (United States); Zachry Department of Civil and Environmental Engineering, Texas A and M University, College Station, TX 77843-3136 (United States)

2008-05-15

Mutagenesis of Escherichia coli for hydrogen production is difficult since there is no high-throughput screen. Here we describe a method for rapid detection of enhanced hydrogen production by engineered strains by detecting formate via potassium permanganate; in E. coli, hydrogen is synthesized from formate using the formate hydrogen lyase system. (author)

Fluoroquinolone-resistant Escherichia coli carriage in long-term care facility.

Science.gov (United States)

Maslow, Joel N; Lee, Betsy; Lautenbach, Ebbing

2005-06-01

We conducted a cross-sectional study to determine the prevalence of, and risk factors for, colonization with fluoroquinolone (FQ)-resistant Escherichia coli in residents in a long-term care facility. FQ-resistant E. coli were identified from rectal swabs for 25 (51%) of 49 participants at study entry. On multivariable analyses, prior FQ use was the only independent risk factor for FQ-resistant E. coli carriage and was consistent for FQ exposures in the previous 3, 6, 9, or 12 months. Pulsed-field gel electrophoresis of FQ-resistant E. coli identified clonal spread of 1 strain among 16 residents. Loss (6 residents) or acquisition (7 residents) of FQ-resistant E. coli was documented and was associated with de novo colonization with genetically distinct strains. Unlike the case in the hospital setting, FQ-resistant E. coli carriage in long-term care facilities is associated with clonal spread.

Mutational Analysis of the RecJ Exonuclease of Escherichia coli: Identification of Phosphoesterase Motifs

OpenAIRE

Sutera, Vincent A.; Han, Eugene S.; Rajman, Luis A.; Lovett, Susan T.

1999-01-01

The recJ gene, identified in Escherichia coli, encodes a Mg+2-dependent 5′-to-3′ exonuclease with high specificity for single-strand DNA. Genetic and biochemical experiments implicate RecJ exonuclease in homologous recombination, base excision, and methyl-directed mismatch repair. Genes encoding proteins with strong similarities to RecJ have been found in every eubacterial genome sequenced to date, with the exception of Mycoplasma and Mycobacterium tuberculosis. Multiple genes encoding protei...

Is Escherichia coli urinary tract infection a zoonosis?

DEFF Research Database (Denmark)

Jacobsen, L.; Garneau, P.; Bruant, G.

2012-01-01

Recently, it has been suggested that the Escherichia coli causing urinary tract infection (UTI) may come from meat and animals. The purpose was to investigate if a clonal link existed between E. coli from animals, meat and UTI patients. Twenty-two geographically and temporally matched B2 E. coli...... from UTI patients, community-dwelling humans, broiler chicken meat, pork, and broiler chicken, previously identified to exhibit eight virulence genotypes by microarraydetection of approximately 300 genes, were investigated for clonal relatedness by PFGE. Nine isolates were selected and tested...... for in vivo virulence in the mouse model of ascending UTI. UTI and community-dwelling human strains were closely clonally related to meat strains. Several human derived strains were also clonally interrelated. All nine isolates regardless of origin were virulent in the UTI model with positive urine, bladder...

Multiplex Genome Editing in Escherichia coli

DEFF Research Database (Denmark)

Ingemann Jensen, Sheila; Nielsen, Alex Toftgaard

2018-01-01

Lambda Red recombineering is an easy and efficient method for generating genetic modifications in Escherichia coli. For gene deletions, lambda Red recombineering is combined with the use of selectable markers, which are removed through the action of, e.g., flippase (Flp) recombinase. This PCR......-based engineering method has also been applied to a number of other bacteria. In this chapter, we describe a recently developed one plasmid-based method as well as the use of a strain with genomically integrated recombineering genes, which significantly speeds up the engineering of strains with multiple genomic...

Crystallization and preliminary X-ray diffraction analysis of the lytic transglycosylase MltE from Escherichia coli

International Nuclear Information System (INIS)

Artola-Recolons, Cecilia; Llarrull, Leticia I.; Lastochkin, Elena; Mobashery, Shahriar; Hermoso, Juan A.

2010-01-01

Crystals of the lytic transglycosylase MltE from E. coli were grown using the microbatch method and diffracted to a resolution of 2.1 Å. MltE from Escherichia coli (193 amino acids, 21 380 Da) is a lytic transglycosylase that initiates the first step of cell-wall recycling. This enzyme is responsible for the cleavage of the cell-wall peptidoglycan at the β-1,4-glycosidic bond between the N-acetylglucosamine and N-acetylmuramic acid units. At the end this reaction generates a disaccharide that is internalized and initiates the recycling process. To obtain insights into the biological functions of MltE, crystallization trials were performed and crystals of MltE protein that were suitable for X-ray diffraction analysis were obtained. The MltE protein of E. coli was crystallized using the hanging-drop vapour-diffusion method at 291 K. Crystals grew from a mixture consisting of 28% polyethylene glycol 4000, 0.1 M Tris pH 8.4 and 0.2 M magnesium chloride. Further optimization was performed using the microbatch technique. Single crystals were obtained that belonged to the orthorhombic space group C222 1 , with unit-cell parameters a = 123.32, b = 183.93, c = 35.29 Å, and diffracted to a resolution of 2.1 Å

Recombinant protein production data after expression in the bacterium Escherichia coli

Directory of Open Access Journals (Sweden)

J. Enrique Cantu-Bustos

2016-06-01

Full Text Available Fusion proteins have become essential for the expression and purification of recombinant proteins in Escherichia coli. The metal-binding protein CusF has shown several features that make it an attractive fusion protein and affinity tag: "Expression and purification of recombinant proteins in Escherichia coli tagged with the metal-binding protein CusF" (Cantu-Bustos et al., 2016 [1]. Here we present accompanying data from protein expression experiments; we tested different protein tags, temperatures, expression times, cellular compartments, and concentrations of inducer in order to obtain soluble protein and low formation of inclusion bodies. Additionally, we present data from the purification of the green fluorescent protein (GFP tagged with CusF, using Ag(I metal affinity chromatography.

Optimizing the feeding operation of recombinant Escherichia coli ...

African Journals Online (AJOL)

Recombinant Escherichia coli BL21 was used to produce human-like collagen in fed-batch culture. After building and analyzing the kinetic models of fed-batch cultures, the maximum specific growth rate, Yx/s and Yp/s were 0.411 h-1 , 0.428 g·g-1 and 0.0716 g/g, respectively. The square error of cell growth models, glucose ...

ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli

OpenAIRE

ANGGREINI, RAHAYU

2015-01-01

2015 RAHAYU ANGGREINI coli Penelitian ini bertujuan untuk melakukan identifikasi cemaran bakteri E. coli O157:H7 pada daging sapi di kota Makassar. Sampel pada penelitian ini sebanyak 72 sampel Kata Kunci : Daging sapi, pasar tradisional, E. coli, E. coli O157:H7, kontaminasi bakteri, identifikasi E. coli O157:H7.

Metabolic impact of an NADH-producing glucose-6-phosphate dehydrogenase in Escherichia coli

DEFF Research Database (Denmark)

Olavarria, K.; De Ingeniis, J.; Zielinski, D. C.

2014-01-01

In Escherichia coli, the oxidative branch of the pentose phosphate pathway (oxPPP) is one of the major sources of NADPH when glucose is the sole carbon nutrient. However, unbalanced NADPH production causes growth impairment as observed in a strain lacking phosphoglucoisomerase (Δpgi). In this work......PDH(R46E,Q47E). Through homologous recombination, the zwf loci (encoding G6PDH) in the chromosomes of WT and Δpgi E. coli strains were replaced by DNA encoding LmG6PDH(R46E,Q47E). Contrary to some predictions performed with flux balance analysis, the replacements caused a substantial effect...

Sequencing of Escherichia coli that cause persistent and transient Mastitis

Science.gov (United States)

The genomes of two strains of Escherichia coli that cause bovine mastitis were sequenced. These strains are known to be associated with persistent and transient mastitis: strain ECA-B causes a transient infection, and ECC-M leads to a persistent infection....

Escherichia coli and other Enterobacteriaceae: Food poisoning and health effects

Science.gov (United States)

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...

Recent Advances in Understanding Enteric Pathogenic Escherichia coli

Science.gov (United States)

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

Clonal study of avian Escherichia coli strains by fliC conserved-DNA-sequence regions analysis Estudo clonal de Escherichia coli aviário por análise de seqüências de DNA conservadas do gene fliC

Directory of Open Access Journals (Sweden)

Tatiana Amabile de Campos

2008-10-01

Full Text Available The clonal relationship among avian Escherichia coli strains and their genetic proximity with human pathogenic E. coli, Salmonela enterica, Yersinia enterocolitica and Proteus mirabilis, was determined by the DNA sequencing of the conserved 5' and 3'regions fliC gene (flagellin encoded gene. Among 30 commensal avian E. coli strains and 49 pathogenic avian E. coli strains (APEC, 24 commensal and 39 APEC strains harbored fliC gene with fragments size varying from 670bp to 1,900bp. The comparative analysis of these regions allowed the construction of a dendrogram of similarity possessing two main clusters: one compounded mainly by APEC strains and by H-antigens from human E. coli, and another one compounded by commensal avian E. coli strains, S. enterica, and by other H-antigens from human E. coli. Overall, this work demonstrated that fliC conserved regions may be associated with pathogenic clones of APEC strains, and also shows a great similarity among APEC and H-antigens of E. coli strains isolated from humans. These data, can add evidence that APEC strains can exhibit a zoonotic risk.A relação clonal entre linhagens de Escherichia coli de origem aviária e sua proximidade genética com E. coli patogênica para humanos, Salmonella enterica, Yersinia enterocolitica e Proteus mirabilis foi determinada através da utilização das seqüências conservadas 5' e 3' do gene fliC (responsável pela codificação da flagelina. Entre as 30 linhagens comensais de E. coli aviária e as 49 linhagens patogênicas de E. coli para aves (APEC, 24 linhagens comensais e 39 APEC apresentaram o gene fliC, que foi encontrado em tamanhos que variam de 670pb a 1900pb. Um dendrograma representando similaridade genética foi obtido a partir do seqüenciamento das regiões 5' e 3' conservadas do gene fliC das linhagens de E. coli de origem aviária, das seqüências dos antígenos H de E. coli de origem humana, de S. enterica, Y. enterocolitica e de P. mirabilis. A an

Transcriptome Changes of Escherichia coli, Enterococcus faecalis, and Escherichia coli O157:H7 Laboratory Strains in Response to Photo-Degraded DOM

Directory of Open Access Journals (Sweden)

Adelumola Oladeinde

2018-05-01

Full Text Available In this study, we investigated gene expression changes in three bacterial strains (Escherichia coli C3000, Escherichia coli O157:H7 B6914, and Enterococcus faecalis ATCC 29212, commonly used as indicators of water quality and as control strains in clinical, food, and water microbiology laboratories. Bacterial transcriptome responses from pure cultures were monitored in microcosms containing water amended with manure-derived dissolved organic matter (DOM, previously exposed to simulated sunlight for 12 h. We used RNA sequencing (RNA-seq and quantitative real-time reverse transcriptase (qRT-PCR to compare differentially expressed temporal transcripts between bacteria incubated in microcosms containing sunlight irradiated and non-irradiated DOM, for up to 24 h. In addition, we used whole genome sequencing simultaneously with RNA-seq to identify single nucleotide variants (SNV acquired in bacterial populations during incubation. These results indicate that E. coli and E. faecalis have different mechanisms for removal of reactive oxygen species (ROS produced from irradiated DOM. They are also able to produce micromolar concentrations of H2O2 from non-irradiated DOM, that should be detrimental to other bacteria present in the environment. Notably, this study provides an assessment of the role of two conjugative plasmids carried by the E. faecalis and highlights the differences in the overall survival dynamics of environmentally-relevant bacteria in the presence of naturally-produced ROS.

Photoinactivation of mcr-1 positive Escherichia coli

Science.gov (United States)

Caires, C. S. A.; Leal, C. R. B.; Rodrigues, A. C. S.; Lima, A. R.; Silva, C. M.; Ramos, C. A. N.; Chang, M. R.; Arruda, E. J.; Oliveira, S. L.; Nascimento, V. A.; Caires, A. R. L.

2018-01-01

The emergence of plasmid-mediated colistin resistance in Enterobacteriaceae, mostly in Escherichia coli due to the mcr-1 gene, has revealed the need to develop alternative approaches in treating mcr-1 positive bacterial infections. This is because colistin is a broad-spectrum antibiotic and one of the ‘last-resort’ antibiotics for multidrug resistant bacteria. The present study evaluated for the first time, to the best of our knowledge, the efficacy of photoinactivation processes to kill a known mcr-1 positive E. coli strain. Eosin methylene-blue (EMB) was investigated as a photoantimicrobial agent for inhibiting the growth of a mcr-1 positive E. coli strain obtained from a patient with a diabetic foot infection. The photoantimicrobial activity of EMB was also tested in a non-multidrug resistant E. coli strain. The photoinactivation process was tested using light doses in the 30-45 J cm-2 range provided by a LED device emitting at 625 nm. Our findings demonstrate that a mcr-1 positive E. coli strain is susceptible to photoinactivation. The results show that the EMB was successfully photoactivated, regardless of the bacterial multidrug resistance; inactivating the bacterial growth by oxidizing the cells in accordance with the generation of the oxygen reactive species. Our results suggest that bacterial photoinactivation is an alternative and effective approach to kill mcr-1 positive bacteria.

D10 value determination for Escherichia coli O157:H7 in different cultivations

International Nuclear Information System (INIS)

Oliveira, Sergio Eduardo M. de; Pires, Luis Fernando G.; Vital, Helio de C.

2002-01-01

Escherichia coli serum type O157:H7 is a highly pathogenic bacterium. Inside the human body, that microorganism causes a disease that leads to bloody diarrhea, stoppage of kidney functions and clots in the brain. That type of infection has been related to the consumption of different varieties of foods, mainly meat and other products of animal origin. Irradiation is an efficient method for elimination of pathogenic and spoiling microorganisms in foods. Thus, this work investigates the use of gamma irradiation for elimination of Escherichia coli O157:H7. For that purpose, inoculated samples in trypticase soy broth and saline solution 0,85% media were exposed to several gamma radiation doses. Counting the number of surviving bacteria yielded the following D 10 values for Escherichia coli O157:H7: 98±7 Gy, in trypticase soy broth and 49±4 Gy in saline solution 0,85% medium. (author)

Genomic and Phenomic Study of Mammary Pathogenic Escherichia coli

Science.gov (United States)

Blum, Shlomo E.; Heller, Elimelech D.; Sela, Shlomo; Elad, Daniel; Edery, Nir; Leitner, Gabriel

2015-01-01

Escherichia coli is a major etiological agent of intra-mammary infections (IMI) in cows, leading to acute mastitis and causing great economic losses in dairy production worldwide. Particular strains cause persistent IMI, leading to recurrent mastitis. Virulence factors of mammary pathogenic E. coli (MPEC) involved pathogenesis of mastitis as well as those differentiating strains causing acute or persistent mastitis are largely unknown. This study aimed to identify virulence markers in MPEC through whole genome and phenome comparative analysis. MPEC strains causing acute (VL2874 and P4) or persistent (VL2732) mastitis were compared to an environmental strain (K71) and to the genomes of strains representing different E. coli pathotypes. Intra-mammary challenge in mice confirmed experimentally that the strains studied here have different pathogenic potential, and that the environmental strain K71 is non-pathogenic in the mammary gland. Analysis of whole genome sequences and predicted proteomes revealed high similarity among MPEC, whereas MPEC significantly differed from the non-mammary pathogenic strain K71, and from E. coli genomes from other pathotypes. Functional features identified in MPEC genomes and lacking in the non-mammary pathogenic strain were associated with synthesis of lipopolysaccharide and other membrane antigens, ferric-dicitrate iron acquisition and sugars metabolism. Features associated with cytotoxicity or intra-cellular survival were found specifically in the genomes of strains from severe and acute (VL2874) or persistent (VL2732) mastitis, respectively. MPEC genomes were relatively similar to strain K-12, which was subsequently shown here to be possibly pathogenic in the mammary gland. Phenome analysis showed that the persistent MPEC was the most versatile in terms of nutrients metabolized and acute MPEC the least. Among phenotypes unique to MPEC compared to the non-mammary pathogenic strain were uric acid and D-serine metabolism. This study

Structural studies on some capsular antigens from Escherichia Coli and Klebsiella

Energy Technology Data Exchange (ETDEWEB)

Anderson, A N

1987-12-01

A review of the structural studies of bacterial capsular polysaccharides (K-antigens) from Escherichia coli (E.coli) and Klebsiella is presented. There is a general trend in the structural elucidation of polysaccharides towards the analysis of higher oligosaccharides. This trend has been facilitated by advances in modern instrumental techniques for the analysis of oligosaccharides, for example, high-performance liquid chromatography, mass spectometry and nuclear magnetic resonance spectroscopy. The structural elucidations of the capsular polysaccharides from E. Coli K37 and K55, and Klebsiella K39 are reported. This elucidation of K-antigens provides an insight into the response of mammalian immune systems to antigenic stimuli. The usefulness of bacteriophage degradation as a technique for the structural elucidation of polysaccharides containing repeating unit structures is emphasized. The bacteriophage degradation of E. coli K55 polysaccharide illustrates that bacteriophage-borne enzymes may be used to degrade chemically related carbohydrate materials. The bacteriophage technique for the structural elucidation of the Klebsiella K39 polysaccharide also illustrates the advantages of this technique where the polysaccharide contains labile glycosidic bonds which are readily cleaved during standard chemical analysis. The enzymatic degradation of polysaccharides allows high yields of specific oligosaccharides to be recovered. The feasibility of analysing small amounts of carbohydrate material has become realistic due to improved instrumental capabilities. At the same time, more detailed information concerning the fine structure of known carbohydrate materials can be elucidated. 421 refs., 56 figs., 16 tabs.

Modeling the inactivation of Escherichia coli 0157:H7 and uropathogenic E.coli in ground chicken by high pressure processing and thymol

Science.gov (United States)

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...

Modeling the inactivatin of Escherichia coli 0157:H7 and uropathogenic E. coli in ground beef by high pressure processing and citral

Science.gov (United States)

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...

Peptide nucleic acid (PNA) antisense effects in Escherichia coli

DEFF Research Database (Denmark)

Good, L; Nielsen, P E

1999-01-01

Antisense peptide nucleic acid (PNA) can be used to control cell growth, gene expression and growth phenotypes in the bacteria Escherichia coli. PNAs targeted to the RNA components of the ribosome can inhibit translation and cell growth, and PNAs targeted to mRNA can limit gene expression with gene...... and sequence specificity. In an E. coli cell extract, efficient inhibition is observed when using PNA concentrations in the nanomolar range, whereas micromolar concentrations are required for inhibition in growing cells. A mutant strain of E. coli that is more permeable to antibiotics also is more susceptible...... to antisense PNAs than the wild type. This chapter details methods for testing the antisense activities of PNA in E. coli. As an example of the specific antisense inhibition possible, we show the effects of an anti-beta-galactosidase PNA in comparison to control PNAs. With improvements in cell uptake...

Analysis of different DNA fragments of Corynebacterium glutamicum complementing dapE of Escherichia coli.

Science.gov (United States)

Wehrmann, A; Eggeling, L; Sahm, H

1994-12-01

In Corynebacterium glutamicum L-lysine is synthesized simultaneously via the succinylase and dehydrogenase variant of the diaminopimelate pathway. Starting from a strain with a disrupted dehydrogenase gene, three different-sized DNA fragments were isolated which complemented defective Escherichia coli mutants in the succinylase pathway. Enzyme studies revealed that in one case the dehydrogenase gene had apparently been reconstituted in the heterologous host. The two other fragments resulted in desuccinylase activity; one of them additionally in succinylase activity. However, the physical analysis showed that structural changes had taken place in all fragments. Using a probe derived from one of the fragments we isolated a 3.4 kb BamHI DNA fragment without selective pressure (by colony hybridization). This was structurally intact and proved functionally to result in tenfold desuccinylase overexpression. The nucleotide sequence of a 1966 bp fragment revealed the presence of one truncated open reading frame of unknown function and that of dapE encoding N-succinyl diaminopimelate desuccinylase (EC 3.5.1.18). The deduced amino acid sequence of the dapE gene product shares 23% identical residues with that from E. coli. The C. glutamicum gene now available is the first gene from the succinylase branch of lysine synthesis of this biotechnologically important organism.

Escherichia coli bacteraemia in patients with and without haematological malignancies

DEFF Research Database (Denmark)

Olesen, B; Kolmos, H J; Orskov, F

1998-01-01

We compared serotypes, virulence factors and susceptibility to antibiotics of Escherichia coli strains isolated from 282 patients with bacteraemia. Thirty-five of these were neutropenic patients with haematological malignancy and 247 were patients with a normal or raised total white blood cell co...

Properties of in situ Escherichia coli -D-glucuronidase (GUS ...

African Journals Online (AJOL)

A study of the activity of Escherichia coli -D-glucuronidase (GUS) in polluted stagnant and running water samples was performed with an objective of assessing the viability of a direct marker enzyme assay as a suitable alternative to membrane filtration for the indication of faecal pollution in water intended for drinking ...

Physiological responses of Escherichia coli to far-ultraviolet radiation

International Nuclear Information System (INIS)

Swenson, P.A.

1976-01-01

The following topics are reviewed: photochemical damage to DNA; measurement of cell survival; DNA repair processes and genetics of radiation sensitivity; degradation of DNA and RNA; biochemical and physiological consequences; reactivation of bacteriophage in Escherichia coli cells; filament formation; influence of growth phase on survival after uv irradiation; and post-uv-irradiation treatment

Novel roles for the AIDA adhesin from diarrheagenic Escherichia coli:

DEFF Research Database (Denmark)

Sherlock, Orla; Schembri, Mark; Reisner, A.

2004-01-01

Diarrhea-causing Escherichia coli strains are responsible for numerous cases of gastrointestinal disease and constitute a serious health problem throughout the world. The ability to recognize and attach to host intestinal surfaces is an essential step in the pathogenesis of such strains. AIDA...... binds to mammalian cells. Here, we show that AIDA possesses self-association characteristics and can mediate autoaggregation of E. coli cells. We demonstrate that intercellular AIDA-AIDA interaction is responsible for bacterial autoaggregation. Interestingly, AIDA-expressing cells can interact...

Escherichia coli : host interactions in the pathogenesis of canine pyometra

OpenAIRE

Henriques, Sofia Correia Rosa de Barros

2016-01-01

Tese de Doutoramento em Ciências Veterinárias na Especialidade de Ciências Biológicas e Biomédicas Canine pyometra develops as a result of a complex interaction of etiological and physiopathological factors, such as the virulence and type of the bacteria and the individual host defence mechanisms. Since Escherichia coli is the most common bacterium isolated from uterus of bitches with pyometra, one main objective of this work was to characterize E. coli virulence potential, and...

Distinct inflammatory and cytopathic characteristics of Escherichia coli isolates from inflammatory bowel disease patients

DEFF Research Database (Denmark)

Jensen, Stina Rikke; Mirsepasi-Lauridsen, Hengameh Chloé; Thysen, Anna Hammerich

2015-01-01

Escherichia coli (E. coli) may be implicated in the pathogenesis of inflammatory bowel disease (IBD), as implied from a higher prevalence of mucosa-associated E. coli in the gut of IBD-affected individuals. However, it is unclear whether different non-diarrheagenic E. coli spp. segregate from eac...

Heterologous expression of mannanase and developing a new Reporter gene system in Lactobacillus casei and Escherichia coli

DEFF Research Database (Denmark)

Lin, Jinzhong; Zou, Yexia; Ma, Chengjie

2015-01-01

Reporter gene systems are useful for studying bacterial molecular biology, including the regulation of gene expression and the histochemical analysis of protein products. Here, two genes, β-1,4-mannanase (manB) from Bacillus pumilus and β-glucuronidase (gusA) from Escherichia coli K12, were clone....... casei and E.coli....

Dark fermentative hydrogen and ethanol production from biodiesel waste glycerol using a co-culture of Escherichia coli and Enterobacter sp.

NARCIS (Netherlands)

Maru, B.T.; López, F.; Kengen, S.W.M.; Constantí, M.; Medina, F.

2016-01-01

In previous comparative studies, Enterobacter spH1 was selected as the best hydrogen and ethanol producer (Knothe, 2010). Here, glycerol fermentation was compared between three other strains: Escherichia coli CECT432, Escherichia coli CECT434 and Enterobacter cloacae MCM2/1. E. coli CECT432 was

Characterization of Escherichia coli isolates from different fecal sources by means of classification tree analysis of fatty acid methyl ester (FAME) profiles.

Science.gov (United States)

Seurinck, Sylvie; Deschepper, Ellen; Deboch, Bishaw; Verstraete, Willy; Siciliano, Steven

2006-03-01

Microbial source tracking (MST) methods need to be rapid, inexpensive and accurate. Unfortunately, many MST methods provide a wealth of information that is difficult to interpret by the regulators who use this information to make decisions. This paper describes the use of classification tree analysis to interpret the results of a MST method based on fatty acid methyl ester (FAME) profiles of Escherichia coli isolates, and to present results in a format readily interpretable by water quality managers. Raw sewage E. coli isolates and animal E. coli isolates from cow, dog, gull, and horse were isolated and their FAME profiles collected. Correct classification rates determined with leaveone-out cross-validation resulted in an overall low correct classification rate of 61%. A higher overall correct classification rate of 85% was obtained when the animal isolates were pooled together and compared to the raw sewage isolates. Bootstrap aggregation or adaptive resampling and combining of the FAME profile data increased correct classification rates substantially. Other MST methods may be better suited to differentiate between different fecal sources but classification tree analysis has enabled us to distinguish raw sewage from animal E. coli isolates, which previously had not been possible with other multivariate methods such as principal component analysis and cluster analysis.

Incidence of Escherichia coli in black walnut meats.

Science.gov (United States)

Meyer, M T; Vaughn, R H

1969-11-01

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.

THE ANTIBACTERIAL ACTIVITY OF WATER APPLE LEAVES ACTIVE COMPOUND (Syzygium zeylanicum AGAINST Escherichia coli AND Staphylococcus aureus

Directory of Open Access Journals (Sweden)

- Hamidah

2017-07-01

Full Text Available Escherichia coli is one of the bacteria that cause infections in the human digestive tract such as diarrhea, while Staphylococcus aureus is one of the bacteria that cause infections in the skin injury such as boils and pimples. This study used Syzygium zeylanicum leaves because it has potential as a antibacterial because it contains active compounds. This study aimed was determine the antibacterial activity of the fraction and the active compound in Syzygium zeylanicum leaves against Escherichia coli and Staphylococcus aureus. Research conducted on November 2015 to January 2016. The method used in this research were extraction by maceration, fractionation by liquid fractionation, antibacterial activity test, and determination of minimum inhibitory concentration with the diffusion method and isolation of active compounds by column chromatography method. The bacteria used in this test are Escherichia coli and Staphylococcus aureus. Data are presented in tabular form based on the average value of the inhibition diameter and deviation standard. The results of this research showed the water methanol active fraction against the bacteria that used in this test. The methanol water fraction had obtained one antibacterial compound in bottle 1,3,5 which shows the value of tannin Rf 0,416. The minimum inhibitory concentration of water methanol of water apple leaves is 1000 µg/mL for Escherichia coli and 500 µg/mL for  Staphylococcus aureus. The minimum  inhibitory concentration of the active  compound  to  Escherichia  coli  and  Staphylococcus  aureus  in  500  µg/mL.  The fraction and the active compound of water apple leaves have an antibacterial activity with Escherichia coli and Staphylococcus aureus and the active compound is tannin.

Metabolic regulation analysis of an ethanologenic Escherichia coli strain based on RT-PCR and enzymatic activities

Directory of Open Access Journals (Sweden)

Martinez Alfredo

2008-05-01

Full Text Available Abstract Background A metabolic regulation study was performed, based upon measurements of enzymatic activities, fermentation performance, and RT-PCR analysis of pathways related to central carbon metabolism, in an ethanologenic Escherichia coli strain (CCE14 derived from lineage C. In comparison with previous engineered strains, this E coli derivative has a higher ethanol production rate in mineral medium, as a result of the elevated heterologous expression of the chromosomally integrated genes encoding PDCZm and ADHZm (pyruvate decarboxylase and alcohol dehydrogenase from Zymomonas mobilis. It is suggested that this behavior might be due to lineage differences between E. coli W and C. Results This study demonstrated that the glycolytic flux is controlled, in this case, by reactions outside glycolysis, i.e., the fermentative pathways. Changes in ethanol production rate in this ethanologenic strain result in low organic acid production rates, and high glycolytic and ethanologenic fluxes, that correlate with enhanced transcription and enzymatic activity levels of PDCZm and ADHZm. Furthermore, a higher ethanol yield (90% of the theoretical in glucose-mineral media was obtained with CCE14 in comparison with previous engineered E. coli strains, such as KO11, that produces a 70% yield under the same conditions. Conclusion Results suggest that a higher ethanol formation rate, caused by ahigher PDCZm and ADHZm activities induces a metabolic state that cells compensate through enhanced glucose transport, ATP synthesis, and NAD-NADH+H turnover rates. These results show that glycolytic enzymatic activities, present in E. coli W and C under fermentative conditions, are sufficient to contend with increases in glucose consumption and product formation rates.

77 FR 58091 - Risk-Based Sampling of Beef Manufacturing Trimmings for Escherichia coli (E. coli) O157:H7 and...

Science.gov (United States)

2012-09-19

... for exposure of carcasses and parts to any contamination or food safety hazard during the removal of... DEPARTMENT OF AGRICULTURE Food Safety and Inspection Service [Docket No. FSIS-2012-0020] Risk-Based Sampling of Beef Manufacturing Trimmings for Escherichia coli (E. coli) O157:H7 and Plans for Beef...

Genes and proteins of Escherichia coli (GenProtEc).

Science.gov (United States)

Riley, M; Space, D B

1996-01-01

GenProtEc is a database of Escherichia coli genes and their gene products, classified by type of function and physiological role and with citations to the literature for each. Also present are data on sequence similarities among E.coli proteins with PAM values, percent identity of amino acids, length of alignment and percent aligned. The database is available as a PKZip file by ftp from mbl.edu/pub/ecoli.exe. The program runs under MS-DOS on IMB-compatible machines. GenProtEc can also be accessed through the World Wide Web at URL http://mbl.edu/html/ecoli.html.

Genomic and transcriptomic analysis of Escherichia coli strains associated with persistent and transient bovine mastitis and the role of colanic acid

Science.gov (United States)

Escherichia coli is a leading cause of bacterial mastitis in dairy cattle. This infection is most often transient in nature, causing an infection that lasts 2–3 days. However, E. coli has been shown to cause a persistent infection in a minority of cases. The mechanisms that allow for a persistent E....

The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan.

Science.gov (United States)

Vanden Heuvel, Amy; McDermott, Colleen; Pillsbury, Robert; Sandrin, Todd; Kinzelman, Julie; Ferguson, John; Sadowsky, Michael; Byappanahalli, Muruleedhara; Whitman, Richard; Kleinheinz, Gregory T

2010-01-01

A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. This study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p Cladophora mats had lower E. coli concentrations, but surpassed EPA swimming criteria the majority of sampling days. A significant positive association was found between E. coli concentrations attached to Cladophora and in underlying water (p Cladophora mats from beach areas may improve aesthetic and microbial water quality at affected beaches. These associations and potential natural growth of E. coli in bathing waters call into question the efficacy of using E. coli as a recreational water quality indicator of fecal contaminations.

Escherichia coli clearance after splenic autotransplants

International Nuclear Information System (INIS)

Marques, R.G.; Petroianu, A.; Oliveira, M.B.N.; Bernardo-Filho, M.; Portela, M.C.

2002-01-01

Background: Splenic autotransplantation seems to be the only alternative for preservation of splenic tissue, after total splenectomy. The present study was carried out to analyze Escherichia coli depuration by mononuclear phagocyte system organs after total splenectomy and splenic autotransplantation. Methods: We utilized an experimental model including young and adult Wistar rats, of both sexes, submitted to total splenectomy and splenic autotransplantation. The evaluation method was intravenous inoculation of a suspension of Escherichia coli labeled with technetium-99m. We analyzed bacteria uptake by mononuclear phagocyte system organs and bacteria remnant in the bloodstream. Results: There was no difference between young and adult animals in bacteria uptake by mononuclear phagocyte system organs. In the comparison of groups, it was found out that the mean percent uptake by spleen and liver of animals in the control group was higher than that observed for animals with splenic implants. However, bacteria uptake in the lung was higher in the splenic implant group than in the control group. Although spleen bacteria uptake in the control group animals has been higher than that of animals in the splenic implant group, the remnant bacteria in the bloodstream was similar. Animals submitted to isolated total splenectomy showed higher bacteria remnant in the bloodstream than animals of the control group or the group submitted to total splenectomy combined with splenic autotransplantation. Conclusion: Our results indicate that autogenous splenic implant is efficacious in bacteria depuration in rats, by means of their macrophages phagocytosis. In addition, it does not modify bacteria removal function of liver and lung

Antibiotic Sensitivity Profile of Escherichia coli Isolated from Poultry ...

African Journals Online (AJOL)

A cross sectional study involving 300 cloaca swabs from apparently healthy birds from 8 small-medium scale poultry farms in Ibadan Oyo State was carried out. A total of 201 (67%) Escherichia coli isolates were recovered from the birds and they were subjected to in-vitro antibiotic sensitivity test by agar gel diffusion method.

Complete Genome Sequence of Enterotoxigenic Escherichia coli Siphophage Seurat.

Science.gov (United States)

Doan, Dung P; Lessor, Lauren E; Hernandez, Adriana C; Kuty Everett, Gabriel F

2015-02-26

Enterotoxigenic Escherichia coli (ETEC) is one of the leading causes of diarrhea in developing countries. Bacteriophage therapy has the potential to aid in the prevention and treatment of ETEC-related illness. To that end, we present here the complete genome of ETEC siphophage Seurat and describe its major features. Copyright © 2015 Doan et al.

Effects of substitutions at position 180 in the Escherichia coli RNA ...

Indian Academy of Sciences (India)

Escherichia coli RNA polymerase, two mutant variants of the protein with substitutions for either alanine or glutamic .... promoter signals utilized for in vitro transcription assays and ..... free recombinant protein using a self-cleavable affinity tag.

Antibiotic trapping by plasmid-encoded cmy-2-lactamase combined with reduced outer membrane permeability as a mechanism of carbapenem resistance in escherichia coli

NARCIS (Netherlands)

W.H.F. Goessens (Wil); A.K. van der Bij (Akke); R. van Boxtel (Ria); J.D.D. Pitout (J. D D); P. van Ulsen (Peter); D.C. Melles (Damian); J. Tommassen (Jan)

2013-01-01

textabstractA liver transplant patient was admitted with cholangitis, for which meropenem therapy was started. Initial cultures showed a carbapenem-susceptible (CS) Escherichia coli strain, but during admission, a carbapenem-resistant (CR) E. coli strain was isolated. Analysis of the outer membrane

Escherichia coli as other Enterobacteriaceae: food poisoning and health effects

Science.gov (United States)

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...

Production of jet fuel precursor monoterpenoids from engineered Escherichia coli

DEFF Research Database (Denmark)

Mendez-Perez, Daniel; Alonso-Gutierrez, Jorge; Hu, Qijun

2017-01-01

). FPP biosynthesis diverts the carbon flux from monoterpene production to C15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate...

Nature of transforming deoxyribonucleic acid in calcium-treated Escherichia coli

International Nuclear Information System (INIS)

Strike, P.; Humphreys, G.O.; Roberts, R.J.

1979-01-01

A study of the reactivation of ultraviolet-irradiated plasmid and phage deoxyribonucleic acid molecules after transformation into Escherichia coli strains indicated that, when double-stranded deoxyribonucleic acid was used as the donor species, it was taken up without conversion to the single-stranded form

Comparative Genomics of Escherichia coli Strains Causing Urinary Tract Infections

DEFF Research Database (Denmark)

Vejborg, Rebecca Munk; Hancock, Viktoria; Schembri, Mark A.

2011-01-01

The virulence determinants of uropathogenic Escherichia coli have been studied extensively over the years, but relatively little is known about what differentiates isolates causing various types of urinary tract infections. In this study, we compared the genomic profiles of 45 strains from a range...

Effect of phytoplankton on Escherichia coli survival in laboratory microcosms

Science.gov (United States)

Fecal contamination of water sources is an important water quality issue for agricultural irrigation ponds. Escherichia coli is a common microbial indicator used to evaluate recreational and irrigation water quality. Nuisance algae commonly grow in low- or no-flow irrigation water source The objecti...

Kwantitatief gevoeligheidsonderzoek met intra- en extramurale isolaten van Escherichia coli

NARCIS (Netherlands)

de Neeling AJ; de Jong J; Overbeek BP; de Bruin RW; Dessens-Kroon M; van Klingeren B

1990-01-01

Three Dutch laboratories for medical microbiology collected a total number of 1432 strains of Escherichia coli. Of these 995 were obtained from routine samples taken in clinic and policlinic, 290 had been sent spontaneously by general practitioners for microbiological examination and 147 had been

Emergence of colistin-resistant Escherichia coli clinical isolates harboring mcr-1 in Vietnam.

Science.gov (United States)

Tada, Tatsuya; Nhung, Pham Hong; Shimada, Kayo; Tsuchiya, Mitsuhiro; Phuong, Doan Mai; Anh, Nguyen Quoc; Ohmagari, Norio; Kirikae, Teruo

2017-10-01

The mcr-1 was first detected on a plasmid in colistin-resistant Escherichia coli from livestock and patients in China. We described here the emergence of colistin-resistant E. coli clinical isolates harboring mcr-1 on the chromosomes in Vietnam. To our knowledge, this is the first report of hospital-acquired E. coli isolates harboring mcr-1 in a medical setting in Vietnam. Copyright © 2017. Published by Elsevier Ltd.

Dynamics of Escherichia coli Chromosome Segregation during Multifork Replication

DEFF Research Database (Denmark)

Nielsen, Henrik Jørck; Youngren, Brenda; Hansen, Flemming G.

2007-01-01

Slowly growing Escherichia coli cells have a simple cell cycle, with replication and progressive segregation of the chromosome completed before cell division. In rapidly growing cells, initiation of replication occurs before the previous replication rounds are complete. At cell division, the chro......Slowly growing Escherichia coli cells have a simple cell cycle, with replication and progressive segregation of the chromosome completed before cell division. In rapidly growing cells, initiation of replication occurs before the previous replication rounds are complete. At cell division......, the chromosomes contain multiple replication forks and must be segregated while this complex pattern of replication is still ongoing. Here, we show that replication and segregation continue in step, starting at the origin and progressing to the replication terminus. Thus, early-replicated markers on the multiple......-branched chromosomes continue to separate soon after replication to form separate protonucleoids, even though they are not segregated into different daughter cells until later generations. The segregation pattern follows the pattern of chromosome replication and does not follow the cell division cycle. No extensive...

Complete genome sequences of Escherichia coli strains 1303 and ECC-1470 isolated from bovine mastitis

NARCIS (Netherlands)

Leimbach, Andreas; Poehlein, Anja; Witten, Anika; Scheutz, Flemming; Schukken, Ynte|info:eu-repo/dai/nl/075051907; Daniel, Rolf; Dobrindt, Ulrich

2016-01-01

Escherichia coli is the leading causative agent of acute bovine mastitis. Here, we report the complete genome sequence of E. coli O70:H32 strain 1303, isolated from an acute case of bovine mastitis, and E. coli Ont:Hnt strain ECC-1470, isolated from a persistent infection.

Radiosensitization of Escherichia coli and Salmonella typhi in presence of active compounds

International Nuclear Information System (INIS)

Lacroix, M.; Chiasson, F.; Borsa, J.; Ouattara, B.

2004-01-01

The radiosensitization of Escherichia coli and Salmonella typhi in ground beef was evaluated in the presence of 18 active compounds. Medium fat ground beef (23% fat) was inoculated with E. coli or S. typhi and each active compound was added separately at various concentrations. For E. coli, the most efficient compounds were trans-cinnamaldehyde, thymol and thyme. For S. typhi, the most efficient compounds was trans-cinnamaldehyde, carvacrol and thymol. The addition of tetrasodium pyrophosphate, carvacrol and ascorbic acid had no effect on the irradiation sensitivity of E. coli. For S. typhi, only ascorbic acid had no effect

Radiosensitization of Escherichia coli and Salmonella typhi in presence of active compounds

Energy Technology Data Exchange (ETDEWEB)

Lacroix, M. E-mail: monique.lacroix@inrs-iaf.uquebec.ca; Chiasson, F.; Borsa, J.; Ouattara, B

2004-10-01

The radiosensitization of Escherichia coli and Salmonella typhi in ground beef was evaluated in the presence of 18 active compounds. Medium fat ground beef (23% fat) was inoculated with E. coli or S. typhi and each active compound was added separately at various concentrations. For E. coli, the most efficient compounds were trans-cinnamaldehyde, thymol and thyme. For S. typhi, the most efficient compounds was trans-cinnamaldehyde, carvacrol and thymol. The addition of tetrasodium pyrophosphate, carvacrol and ascorbic acid had no effect on the irradiation sensitivity of E. coli. For S. typhi, only ascorbic acid had no effect.

Escherichia coli tRNAArg acceptor-stem isoacceptors: comparative crystallization and preliminary X-ray diffraction analysis

International Nuclear Information System (INIS)

Eichert, André; Schreiber, Angela; Fürste, Jens P.; Perbandt, Markus; Betzel, Christian; Erdmann, Volker A.; Förster, Charlotte

2009-01-01

Various E. coli tRNA Arg acceptor-stem microhelix isoacceptors have been crystallized and investigated by high-resolution X-ray diffraction analysis. The aminoacylation of tRNA is a crucial step in cellular protein biosynthesis. Recognition of the cognate tRNA by the correct aminoacyl-tRNA synthetase is ensured by tRNA identity elements. In tRNA Arg , the identity elements consist of the anticodon, parts of the D-loop and the discriminator base. The minor groove of the aminoacyl stem interacts with the arginyl-tRNA synthetase. As a consequence of the redundancy of the genetic code, six tRNA Arg isoacceptors exist. In the present work, three different Escherichia coli tRNA Arg acceptor-stem helices were crystallized. Two of them, the tRNA Arg microhelices RR-1660 and RR-1662, were examined by X-ray diffraction analysis and diffracted to 1.7 and 1.8 Å resolution, respectively. The tRNA Arg RR-1660 helix crystallized in space group P1, with unit-cell parameters a = 26.28, b = 28.92, c = 29.00 Å, α = 105.74, β = 99.01, γ = 97.44°, whereas the tRNA Arg RR-1662 helix crystallized in space group C2, with unit-cell parameters a = 33.18, b = 46.16, c = 26.04 Å, β = 101.50°

Molecular prophage typing of avian pathogenic Escherichia coli.

Science.gov (United States)

Kwon, Hyuk-Joon; Seong, Won-Jin; Kim, Jae-Hong

2013-03-23

Escherichia coli prophages confer virulence and resistance to physico-chemical, nutritional, and antibiotic stresses on their hosts, and they enhance the evolution of E. coli. Thus, studies on profiles of E. coli prophages are valuable to understand the population structure and evolution of E. coli pathogenicity. Large terminase genes participate in phage genome packaging and are one of the cornerstones for the identification of prophages. Thus, we designed primers to detect 16 types of large terminase genes and analyzed the genomes of 48 E. coli and Shigella reference strains for the prophage markers. We also investigated the distribution of the 16 prophage markers among 92 avian pathogenic E. coli (APEC) strains. APEC strains were classified into 61 prophage types (PPTs). Each strain was different from the reference strains as measured by the PPTs and from the frequency of each prophage marker. Investigation of the distribution of prophage-related serum resistance (bor), toxin (stx1 and cdtI), and T3SS effector (lom, espK, sopE, nleB, and ospG) genes revealed the presence of bor (44.1%), lom (95.5%) and cdtI (9.1%) in APEC strains with related prophages. Therefore, the molecular prophage typing method may be useful to understand population structure and evolution of E. coli pathogenicity, and further studies on the mobility of the prophages and the roles of virulence genes in APEC pathogenicity may be valuable. Copyright © 2012 Elsevier B.V. All rights reserved.

Genetic Analysis of Diaminopimelic Acid- and Lysine-Requiring Mutants of Escherichia coli1

Science.gov (United States)

Bukhari, Ahmad I.; Taylor, Austin L.

1971-01-01

Several diaminopimelic acid (DAP)- and lysine-requiring mutants of Escherichia coli were isolated and studied by genetic, physiological, and biochemical means. The genes concerned with DAP-lysine synthesis map at several different sites on the E. coli chromosome and, therefore, do not constitute a single operon. Three separate loci affecting DAP synthesis are located in the 0 to 2.5 min region of the genetic map. The order of the loci in this region is thr-dapB-pyrA-ara-leu-pan-dapC-tonA-dapD. Two additional DAP genes map in the region between min 47 and 48, with the gene order being gua-dapA-dapE-ctr. The lys locus at min 55 determines the synthesis of the enzyme DAP decarboxylase, which catalyzes the conversion of DAP into lysine. The order of the genes in this region is serA-lysA-thyA. PMID:4926684

The enhanced UV-sensitivity of Escherichia coli uvr A crp strain

International Nuclear Information System (INIS)

Skavronskaya, A.G.; Aleshkin, G.I.

1979-01-01

Mutations in genes cya and crp do not affect the UV cell sensitivity of Escherichia coli of wild type in relation to repairs of UV-injuries and UV induced mutations yield. Mutations in gene crp (protein defect of catabolitic activator - cap) result in UV sensitivity decrease of E. coli uvrA strain, imperfect as to the first stage of excision repairs not decreasing the quantity of revertants, induced by the UV-light

Prevalence of Avian Pathogenic Escherichia coli (APEC Clone Harboring sfa Gene in Brazil

Directory of Open Access Journals (Sweden)

Terezinha Knöbl

2012-01-01

Full Text Available Escherichia coli sfa+ strains isolated from poultry were serotyped and characterized by polymerase chain reaction (PCR and amplified fragment length polymorphism (AFLP. Isolates collected from 12 Brazilian poultry farms mostly belonged to serogroup O6, followed by serogroups O2, O8, O21, O46, O78, O88, O106, O111, and O143. Virulence genes associated were: iuc 90%, fim 86% neuS 60%, hly 34%, tsh 28%, crl/csg 26%, iss 26%, pap 18%, and 14% cnf. Strains from the same farm presented more than one genotypic pattern belonging to different profiles in AFLP. AFLP showed a clonal relation between Escherichia coli sfa+ serogroup O6. The virulence genes found in these strains reveal some similarity with extraintestinal E. coli (ExPEC, thus alerting for potential zoonotic risk.

Modeling base excision repair in Escherichia coli bacterial cells

International Nuclear Information System (INIS)

Belov, O.V.

2011-01-01

A model describing the key processes in Escherichia coli bacterial cells during base excision repair is developed. The mechanism is modeled of damaged base elimination involving formamidopyrimidine DNA glycosylase (the Fpg protein), which possesses several types of activities. The modeling of the transitions between DNA states is based on a stochastic approach to the chemical reaction description

Prevalence of Antibiotic-Resistant Strains of Escherichia coli in ...

African Journals Online (AJOL)

A total of six bacteria species Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, Klebsiella pneumonia, Staphylococcus aureus, Enterobacter aerogenes were ... Énumération de nombre de plaque standard a été effectuée par la méthode de la plaque de propagation sur des échantillons d'eau dilués en série.

Genes under positive selection in Escherichia coli

DEFF Research Database (Denmark)

Petersen, Lise; Bollback, Jonathan P; Dimmic, Matt

2007-01-01

We used a comparative genomics approach to identify genes that are under positive selection in six strains of Escherichia coli and Shigella flexneri, including five strains that are human pathogens. We find that positive selection targets a wide range of different functions in the E. coli genome......, including cell surface proteins such as beta barrel porins, presumably because of the involvement of these genes in evolutionary arms races with other bacteria, phages, and/or the host immune system. Structural mapping of positively selected sites on trans-membrane beta barrel porins reveals...... that the residues under positive selection occur almost exclusively in the extracellular region of the proteins that are enriched with sites known to be targets of phages, colicins, or the host immune system. More surprisingly, we also find a number of other categories of genes that show very strong evidence...

Seagulls and beaches as reservoirs for multidrug-resistant Escherichia coli.

Science.gov (United States)

Simões, Roméo Rocha; Poirel, Laurent; Da Costa, Paulo Martins; Nordmann, Patrice

2010-01-01

A variety of extended-spectrum Beta-lactamase-producing Escherichia coli isolates, with a high rate of cefotaximase-15 resistance, were identified in seagull feces from Porto, Portugal, beaches. Beaches may therefore present a risk to public health because of the potential pathogen-spreading capacity of migratory birds.

Seagulls and Beaches as Reservoirs for Multidrug-Resistant Escherichia coli

OpenAIRE

Simões, Roméo Rocha; Poirel, Laurent; Da Costa, Paulo Martins; Nordmann, Patrice

2009-01-01

A variety of extended-spectrum ?-lactamase?producing Escherichia coli isolates, with a high rate of cefotaximase-15 resistance, were identified in seagull feces from Porto, Portugal, beaches. Beaches may therefore present a risk to public health because of the potential pathogen-spreading capacity of migratory birds.

DNA supercoiling depends on the phosphorylation potential in Escherichia coli

DEFF Research Database (Denmark)

Van Workum, M.; van Dooren, S.J.M; Oldenburg, N

1996-01-01

ATP/ADP ratios were varied in different ways and the degree of negative supercoiling was determined in Escherichia coli. Independent of whether the ATP/ADP ratio was reduced by a shift to anaerobic conditions, by addition of protonophore (dinitrophenol) or by potassium cyanide addition, DNA super...

Differential expression of the Escherichia coli autoaggregation factor antigen 43

DEFF Research Database (Denmark)

Schembri, Mark; Hjerrild, Louise; Gjermansen, Morten

2003-01-01

Antigen 43 (Ag43) is a self-recognizing surface adhesin found in most Escherichia coli strains. Due to its excellent cell-to-cell aggregation characteristics, Ag43 expression confers clumping and fluffing of cells and promotes biofilm formation. Ag43 expression is repressed by the cellular redox...

iML1515, a knowledgebase that computes Escherichia coli traits

DEFF Research Database (Denmark)

Monk, Jonathan M.; Lloyd, Colton J.; Brunk, Elizabeth

2017-01-01

To the Editor: Extracting knowledge from the many types of big data produced by high-throughput methods remains a challenge, even when data are from Escherichia coli, the best characterized bacterial species. Here, we present iML1515, the most complete genome-scale reconstruction of the metabolic...

Decolorization of dyes by recombinase CotA from Escherichia coli ...

African Journals Online (AJOL)

The CotA laccase could efficiently decolorize anthraquinone and azo dyes in 24 h. The decolourization capacity of this recombinant laccase suggested that it could be a useful biocatalyst for the treatment of dye-containing effluents. Key words: Recombinant CotA laccase, Escherichia coli, purification, dye decolorization.

Search for Enterohaemorrhagic Escherichia coli O157:H7 and ...

African Journals Online (AJOL)

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 and Salmonella enterica are important zoonotic bacteria responsible for enteric infections in humans. The present study investigated the possible role of kittens in the zoonotic transmission of antimicrobial resistant EHEC O157 and Salmonella enterica to human using ...

Molecular characterization of the Escherichia coli asymptomatic bacteriuria strain 83972

DEFF Research Database (Denmark)

Klemm, Per; Hancock, Viktoria; Ulett, G.C.

2006-01-01

Escherichia coli 83972 is a clinical asymptomatia bacteriuric isolate that is able to colonize the human urinary bladder without inducing an immune response. Here we demonstrate that one of the mechanisms by which this strain has become attenuated is through the mutation of its genes encoding type...

Detection of Escherichia Coli O157:H7 in Fecal Samples in Meat Goats

Science.gov (United States)

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…

Loop-mediated isothermal amplification assay for rapid detection of common strains of Escherichia coli.

Science.gov (United States)

Hill, Joshua; Beriwal, Shilpa; Chandra, Ishwad; Paul, Vinod K; Kapil, Aarti; Singh, Tripti; Wadowsky, Robert M; Singh, Vinita; Goyal, Ankur; Jahnukainen, Timo; Johnson, James R; Tarr, Phillip I; Vats, Abhay

2008-08-01

We developed a highly sensitive and specific LAMP assay for Escherichia coli. It does not require DNA extraction and can detect as few as 10 copies. It detected all 36 of 36 E. coli isolates and all 22 urine samples (out of 89 samples tested) that had E. coli. This assay is rapid, low in cost, and simple to perform.

Escherichia coli ST131, an Intriguing Clonal Group

Science.gov (United States)

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

Lethality prediction for Escherichia coli 0157:H7 and Uropathogenic E. coli in ground chicken treated with high pressure processing and trans-cinnamaldehyde

Science.gov (United States)

Pathogenic Escherichia coli, intestinal (O157:H7) as well as extraintestinal types (Uropathogenic E. coli (UPEC)) are commonly found in many foods including chicken meat. In this study we compared the resistance of E. coli O157:H7 to UPEC in chicken meat under the stresses of high hydrostatic pressu...

Transcriptomic analysis displays the effect of (-)-roemerine on the motility and nutrient uptake in Escherichia coli.

Science.gov (United States)

Ayyildiz, Dilara; Arga, Kazim Yalcin; Avci, Fatma Gizem; Altinisik, Fatma Ece; Gurer, Caglayan; Gulsoy Toplan, Gizem; Kazan, Dilek; Wozny, Katharina; Brügger, Britta; Mertoglu, Bulent; Sariyar Akbulut, Berna

2017-08-01

Among the different families of plant alkaloids, (-)-roemerine, an aporphine type, was recently shown to possess significant antibacterial activity in Escherichia coli. Based on the increasing demand for antibacterials with novel mechanisms of action, the present work investigates the potential of the plant-derived alkaloid (-)-roemerine as an antibacterial in E. coli cells using microarray technology. Analysis of the genome-wide transcriptional reprogramming in cells after 60 min treatment with 100 μg/mL (-)-roemerine showed significant changes in the expression of 241 genes (p value 2). Expression of selected genes was confirmed by qPCR. Differentially expressed genes were classified into functional categories to map biological processes and molecular pathways involved. Cellular activities with roles in carbohydrate transport and metabolism, energy production and conversion, lipid transport and metabolism, amino acid transport and metabolism, two-component signaling systems, and cell motility (in particular, the flagellar organization and motility) were among metabolic processes altered in the presence of (-)-roemerine. The down-regulation of the outer membrane proteins probably led to a decrease in carbohydrate uptake rate, which in turn results in nutrient limitation. Consequently, energy metabolism is slowed down. Interestingly, the majority of the expressional alterations were found in the flagellar system. This suggested reduction in motility and loss in the ability to form biofilms, thus affecting protection of E. coli against host cell defense mechanisms. In summary, our findings suggest that the antimicrobial action of (-)-roemerine in E. coli is linked to disturbances in motility and nutrient uptake.

Expression, crystallization and preliminary X-ray analysis of the periplasmic stress sensory protein RseB from Escherichia coli

International Nuclear Information System (INIS)

Wollmann, Petra; Zeth, Kornelius

2006-01-01

The periplasmic stress protein RseB from E. coli was cloned, expressed and crystallized. Crystallographic data are presented and structure solution using the multiple isomorphous replacement approach (MIR) is in progress. Sensing external stress in the bacterial periplasm and signal transduction to the cytoplasm are important functions of the CpxAR, Bae and σ E signalling pathways. In Escherichia coli, the σ E pathway can be activated through degradation of the antisigma factor RseA by DegS and YaeL. The periplasmic protein RseB plays an important role in this pathway by exerting a direct or indirect negative effect on YaeL cleavage efficiency. RseB from E. coli, missing the periplasmic signal sequence (RseB ΔN ), was cloned, expressed, purified and crystallized. Crystals were obtained in two different forms belonging to space group P42 1 2 (form I) and C222 1 (form II) and diffracted to 2.8 and 2.4 Å resolution, respectively. In crystal form I two copies of the protein were located in the asymmetric unit according to heavy-atom analysis, while crystal form II contained three copies

Interaction of Escherichia coli with growing salad spinach plants.

Science.gov (United States)

Warriner, Keith; Ibrahim, Faozia; Dickinson, Matthew; Wright, Charles; Waites, William M

2003-10-01

In this study, the interaction of a bioluminescence-labeled Escherichia coli strain with growing spinach plants was assessed. Through bioluminescence profiles, the direct visualization of E. coli growing around the roots of developing seedlings was accomplished. Subsequent in situ glucuronidase (GUS) staining of seedlings confirmed that E. coli had become internalized within root tissue and, to a limited extent, within hypocotyls. When inoculated seeds were sown in soil microcosms and cultivated for 42 days, E. coli was recovered from the external surfaces of spinach roots and leaves as well as from surface-sterilized roots. When 20-day-old spinach seedlings (from uninoculated seeds) were transferred to soil inoculated with E. coli, the bacterium became established on the plant surface, but internalization into the inner root tissue was restricted. However, for seedlings transferred to a hydroponic system containing 10(2) or 10(3) CFU of E. coli per ml of the circulating nutrient solution, the bacterium was recovered from surface-sterilized roots, indicating that it had been internalized. Differences between E. coli interactions in the soil and those in the hydroponic system may be attributed to greater accessibility of the roots in the latter model. Alternatively, the presence of a competitive microflora in soil may have restricted root colonization by E. coli. The implications of this study's findings with regard to the microbiological safety of minimally processed vegetables are discussed.

Volunteer Challenge With Enterotoxigenic Escherichia coli That Express Intestinal Colonization Factor Fimbriae CS17 and CS19

Science.gov (United States)

2011-07-01

Serotype was determined by classic serological methods at the Universidad Nacional Aut6noma de Mexico [UNAMl. H- indrcates non-motility. b CF...Levine MM, Merson MM. Serologic differentiation between antitoxin responses to infection with Vibrio cholerae and enterotoxin-producing Escherichia coli...prototype cholera B subunit-colonization factor antigen cnterotoxigenic Escherichia coli vaccine. Vaccine 1993; 1[:929-34. 15. Levine MM, Nalin DR

Strain-Level Discrimination of Shiga Toxin-Producing Escherichia coli in Spinach Using Metagenomic Sequencing.

Directory of Open Access Journals (Sweden)

Susan R Leonard

Full Text Available Consumption of fresh bagged spinach contaminated with Shiga toxin-producing Escherichia coli (STEC has led to severe illness and death; however current culture-based methods to detect foodborne STEC are time consuming. Since not all STEC strains are considered pathogenic to humans, it is crucial to incorporate virulence characterization of STEC in the detection method. In this study, we assess the comprehensiveness of utilizing a shotgun metagenomics approach for detection and strain-level identification by spiking spinach with a variety of genomically disparate STEC strains at a low contamination level of 0.1 CFU/g. Molecular serotyping, virulence gene characterization, microbial community analysis, and E. coli core gene single nucleotide polymorphism (SNP analysis were performed on metagenomic sequence data from enriched samples. It was determined from bacterial community analysis that E. coli, which was classified at the phylogroup level, was a major component of the population in most samples. However, in over half the samples, molecular serotyping revealed the presence of indigenous E. coli which also contributed to the percent abundance of E. coli. Despite the presence of additional E. coli strains, the serotype and virulence genes of the spiked STEC, including correct Shiga toxin subtype, were detected in 94% of the samples with a total number of reads per sample averaging 2.4 million. Variation in STEC abundance and/or detection was observed in replicate spiked samples, indicating an effect from the indigenous microbiota during enrichment. SNP analysis of the metagenomic data correctly placed the spiked STEC in a phylogeny of related strains in cases where the indigenous E. coli did not predominate in the enriched sample. Also, for these samples, our analysis demonstrates that strain-level phylogenetic resolution is possible using shotgun metagenomic data for determining the genomic relatedness of a contaminating STEC strain to other

Resistência a antimicrobianos de Escherichia coli isolada de dejetos suínos em esterqueiras Antibiotic-resistance of Escherichia coli isolates from stored pig slurry

Directory of Open Access Journals (Sweden)

F.F.P. Silva

2008-06-01

Full Text Available The antimicrobial resistance of 96 Escherichia coli strains isolated from a stabilization pond system on a pig-breeding farm was evaluated. Strains were tested for their resistance against 14 antimicrobial using the agar diffusion method. E. coli strains showed resistance to tetracycline (82.3%, nalidixic acid (64%, ampicilin (41%, sulfamethoxazole/trimethoprin (36%, sulfonamide (34%, cloranphenicol (274%, ciprofloxacin (19%, cefaclor (16%, streptomicyn (7.3%, neomicyn (1%, amoxacilin/ clavulanic acid (1%, and amikacin (1%. No resistance was observed to gentamicin and tobramycin, and 37.5% of E. coli strains were resistant to four or more antimicrobials. The multiresistance pattern was found in strains isolated during all sampled period. Strains showed a high variability in the antimicrobial resistance pattern.

GENETIC CONTROL OF RESTRICTION AND MODIFICATION IN ESCHERICHIA COLI1

Science.gov (United States)

Boyer, Herbert

1964-01-01

Boyer, Herbert (Yale University, New Haven, Conn.). Genetic control of restriction and modification in Escherichia coli. J. Bacteriol. 88:1652–1660. 1964.—Bacterial crosses with K-12 strains of Escherichia coli as Hfr donors (Hfr Hayes, Hfr Cavalli, and Hfr P4X-6) and B/r strains of E. coli as F− recipients were found to differ from crosses between K-12 Hfr donors and K-12 F− recipients in two ways: (i) recombinants (leu, pro, lac, and gal) did not appear at discrete time intervals but did appear simultaneously 30 min after matings were initiated, and (ii) the linkage of unselected markers to selected markers was reduced. Integration of a genetic region linked to the threonine locus of K-12 into the B/r genome resulted in a hybrid which no longer gave anomalous results in conjugation experiments. A similar region of the B strain was introduced into the K-12 strain, which then behaved as a typical B F− recipient. These observations are interpreted as the manifestation of host-controlled modification and restriction on the E. coli chromosome. This was verified by experiments on the restriction and modification of the bacteriophage lambda, F-lac, F-gal, and sex-factor, F1. It was found that the genetic region that controlled the mating responses of the K-12 and B/r strains also controlled the modification and restriction properties of these two strains. The genes responsible for the restricting and modifying properties of the K-12 and B strains of E. coli were found to be allelic, linked to each other, and linked to the threonine locus. PMID:14240953

The lon gene and photoprotection in Escherichia coli K-12

International Nuclear Information System (INIS)

Waksman, G.; Thomas, G.; Favre, A.

1984-01-01

Photoprotection, i.e. the increased resistance of the cells preilluminated with near ultraviolet light (300-380 nm) to the lethal action of 254nm radiations requires either an integrated prophage or a recA mutation in Escherichia coli K12 strains. Significant photoprotection occurs in an Escherichia coli K12 recA + cell containing the lon allele responsible for filamentous growth after 254nm irradiation. The Fil phenotype can be suppressed by the sfiA or sfiB suppressor genes. Since the E. coli K12 recA + lon sfiB strain exhibits no more photoprotection, it is concluded that in lon strains photoprotection is due to the abolition of the 254nm induced filamentation by the near ultraviolet treatment. In addition, near ultraviolet illumination of the cells leads to a severe restriction of the bulk protein synthesis. This effect is observed only in nuv + cells that contain 4-thiouridine the chromophore responsible for photoprotection. It is proposed that in lon (lysogenic strains) photoprotection is due to prevention of the SOS response. During the growth lag, the low residual level of protein synthesis does not allow the induction of the SOS response and accordingly prevents filamentation (the lytic cycle). (author)

DNA turnover and strand breaks in Escherichia coli

International Nuclear Information System (INIS)

Hanawalt, P.; Grivell, A.; Nakayama, H.

1975-01-01

The extent of DNA turnover has been measured in a dnaB mutant of Escherichia coli, temperature sensitive for semiconservative DNA replication. At the nonpermissive temperature about 0.02 percent of the deoxynucleotides in DNA are exchanged per generation period. This turnover rate is markedly depressed in the presence of rifampicin. During thymine starvation strand breaks accumulate in the DNA of E. coli strains that are susceptible to thymineless death. Rifampicin suppresses the appearance of these breaks, consistent with our hypothesis that transcription may be accompanied by repairable single-strand breaks in DNA. DNA turnover is enhanced severalfold in strands containing 5-bromodeoxyuridine in place of thymidine, possibly because the analog (or the deoxyuridine, following debromination) is sometimes recognized and excised

Construction of a minimum-size functional flagellin of Escherichia coli.

OpenAIRE

Kuwajima, G

1988-01-01

Various deletions were introduced into the central region of Escherichia coli flagellin (497 residues) without destroying its ability to form flagellar filaments. The smallest flagellin retained only the N-terminal 193 residues and the C-terminal 117 residues, which are suggested to be the domains essential for filament formation.

Escherichia coli. A sanitary methodology for faecal water pollution tests

International Nuclear Information System (INIS)

Bonadonna, L.

2001-01-01

Among the traditional indictors of faecal water pollution, Escherichia coli has shown to fit better with the definition of indicator organism. Till now its recovery has been time-consuming and needs confirmation tests. In this report more rapid and direct methods, based on enzymatic reactions, are presented [it

Cloning and expression of the Escherichia coli K-12 sad gene.

OpenAIRE

Marek, L E; Henson, J M

1988-01-01

The Escherichia coli K-12 sad gene, which encodes an NAD-dependent succinic semialdehyde dehydrogenase, was cloned into a high-copy-number vector. Minicells carrying a sad+ plasmid produced a 55,000-dalton peptide, the probable sad gene product.

Preliminary structural investigations of the Eut-L shell protein of the ethanolamine ammonia-lyase metabolosome of Escherichia coli

International Nuclear Information System (INIS)

Nikolakakis, Kiel; Ohtaki, Akashi; Newton, Keith; Chworos, Arkadiusz; Sagermann, Martin

2009-01-01

Preliminary X-ray analysis of crystals of the bacterial microcompartment shell protein Eut-L from Escherichia coli is reported. The ethanolamine ammonia-lyase microcompartment is composed of five different shell proteins that have been proposed to assemble into symmetrically shaped polyhedral particles of varying sizes. Here, preliminary X-ray analysis of crystals of the bacterial microcompartment shell protein Eut-L from Escherichia coli is reported. Cloning, overexpression and purification resulted in highly pure protein that crystallized readily under many different conditions. In all cases the protein forms thin hexagonal plate-shaped crystals belonging to space group P3 that are of unusually high stability against different solvent conditions. The crystals diffracted to a resolution of 2.0 Å using synchrotron radiation but proved to be radiation-sensitive. Preparations of heavy-atom-derivatized crystals for use in determining the three-dimensional structure are under way

Incidence of Escherichia coli O157:H7 in Thailand

International Nuclear Information System (INIS)

Sukhumungoon, P.

2015-01-01

Entero hemorrhagic Escherichia coli (EHEC) especially serotype O157:H7 is one of the important food-borne pathogens because it is able to produce crucial toxins Shiga. However, the outbreak of this organism in Thailand has not been reported. Antibody to O157 antigen was detected in some Thai populations and Shiga toxin-producing E. coli were detected in low numbers of clinical specimens. Interestingly, some E. coli that showed positive to O157 fimbriae probe and lack of virulence gene were isolated from certain patients and one isolate of E. coli O157:H7 which possessed stx1, stx2v was detected in a normal child. In addition, the incidence of E. coli O157:H7 strains were monitored by the samples from cattle and retail beef in Thailand although their inability to produce toxins or produce in a low concentration was demonstrated. This review discusses the incidences of E. coli O157 in clinical and environmental samples of Thailand including the transmission possibility of this bacterium across the Thai border through food trade. (author)

Transferability of antimicrobial resistance from multidrug-resistant Escherichia coli isolated from cattle in the USA to E. coli and Salmonella Newport recipients

Science.gov (United States)

The objective of this study was to evaluate conjugative transfer of cephalosporin resistance among (n=100) strains of multi-drug resistant Escherichia coli (MDRE) to Salmonella Newport and E. coli DH5-alpha recipients. To accomplish this, phenotypic and genotypic profiles were determined for MDRE, ...

Antibiotic Trapping by Plasmid-Encoded CMY-2 beta-Lactamase Combined with Reduced Outer Membrane Permeability as a Mechanism of Carbapenem Resistance in Escherichia coli

NARCIS (Netherlands)

Goessens, W.H.F.; van der Bij, A.K.; van Boxtel, R.; Pitout, J.D.D.; van Ulsen, J.P.; Melles, D.C.; Tommassen, J.

2013-01-01

A liver transplant patient was admitted with cholangitis, for which meropenem therapy was started. Initial cultures showed a carbapenem-susceptible (CS) Escherichia coli strain, but during admission, a carbapenem-resistant (CR) E. coli strain was isolated. Analysis of the outer membrane protein

FREQUENCY AND DISTRIBUTION OF DIARRHOEAGENIC ESCHERICHIA COLI STRAINS ISOLATED FROM PEDIATRIC PATIENTS WITH DIARRHOEA IN BOSNIA AND HERZEGOVINA

OpenAIRE

Dedeić-Ljubović, AmeLa; Hukić, Mirsada; Bekić, DaRia; Zvizdić, AmrA

2009-01-01

Diarrhoeal disease is a major cause of illness and death among infants and young children worldwide. Among the Escherichia coli (E. coli) causing intestinal diseases, there are six well-described categories: enteroaggregative E. coli (EAEC), diffusely adherent E. coli (DAEC), enteroinvasive E. coli (EIEC), entero-pathogenic E. coli (EPEC), enterohaemorrhagic E. coli (EHEC) and enterotoxigenic E. coli (ETEC).

The first 30 years of Shiga toxin-producing Escherichia coli in cattle production: Incidence, preharvest ecology, and management

Science.gov (United States)

Of the 700 serotypes of Escherichia coli, most are commensal; however, some range from mildly to highly pathogenic and can cause death. The disease-causing enterovirulent E. coli are classified as: Enterotoxigenic E. coli (ETEC), Enteropathogenic E. coli (EPEC), Enteroinvasive E. coli (EIEC), and ...

The Escherichia coli Phosphoenolpyruvate-Dependent Phosphotransferase System : Observation of Heterogeneity in the Amino Acid Composition of HPr

NARCIS (Netherlands)

Roossien, F.F.; Dooijewaard, G.; Robillard, G.T.

1979-01-01

Resonances of the aromatic protons of tyrosine have been observed in the proton nuclear magnetic resonance (1H NMR) spectrum of purified HPr from Escherichia coli. Analysis of the NMR spectrum of native HPr suggests that the tyrosine is located in a single position in the secondary structure and

Investigations into the design principles in the chemotactic behavior of Escherichia coli.

Science.gov (United States)

Kim, Tae-Hwan; Jung, Sung Hoon; Cho, Kwang-Hyun

2008-01-01

Inspired by the recent studies on the analysis of biased random walk behavior of Escherichia coli[Passino, K.M., 2002. Biomimicry of bacterial foraging for distributed optimization and control. IEEE Control Syst. Mag. 22 (3), 52-67; Passino, K.M., 2005. Biomimicry for Optimization, Control and Automation. Springer-Verlag, pp. 768-798; Liu, Y., Passino, K.M., 2002. Biomimicry of social foraging bacteria for distributed optimization: models, principles, and emergent behaviors. J. Optim. Theory Appl. 115 (3), 603-628], we have developed a model describing the motile behavior of E. coli by specifying some simple rules on the chemotaxis. Based on this model, we have analyzed the role of some key parameters involved in the chemotactic behavior to unravel the underlying design principles. By investigating the target tracking capability of E. coli in a maze through computer simulations, we found that E. coli clusters can be controlled as target trackers in a complex micro-scale-environment. In addition, we have explored the dynamical characteristics of this target tracking mechanism through perturbation of parameters under noisy environments. It turns out that the E. coli chemotaxis mechanism might be designed such that it is sensitive enough to efficiently track the target and also robust enough to overcome environmental noises.

Effect of heat treatment on the survival of Escherichia Coli O157:H7 ...

African Journals Online (AJOL)

The survival of Escherichia coli O157:H7 in raw milk treated in experimental pasteurizer was investigated in the year 2010. Raw milk was inoculated with different initial concentrations of E. coli O157:H7 and heated for 15 seconds at temperatures ranging from 69OC to 73OC. E. coli O157:H7 cells were not isolated from the ...

Evolved Escherichia coli Strains for Amplified, Functional Expression of Membrane Proteins

NARCIS (Netherlands)

Gul, Nadia; Linares, Daniel M.; Ho, Franz Y.; Poolman, Bert

2014-01-01

The major barrier to the physical characterization and structure determination of membrane proteins is low protein yield and/or low functionality in recombinant expression. The enteric bacterium Escherichia coli is the most widely employed organism for producing recombinant proteins. Beside several

The Enzymology of Protein Translocation across the Escherichia coli Plasma Membrane

NARCIS (Netherlands)

Wickner, William; Driessen, Arnold J.M.; Hartl, Franz-Ulrich

1991-01-01

Converging physiological, genetic, and biochemical studies have established the salient features of preprotein translocation across the plasma membrane of Escherichia coli. Translocation is catalyzed by two proteins, a soluble chaperone and a membrane-bound translocase. SecB, the major chaperone for

Analysis of l-glutamic acid fermentation by using a dynamic metabolic simulation model of Escherichia coli

OpenAIRE

Nishio, Yousuke; Ogishima, Soichi; Ichikawa, Masao; Yamada, Yohei; Usuda, Yoshihiro; Masuda, Tadashi; Tanaka, Hiroshi

2013-01-01

Background Understanding the process of amino acid fermentation as a comprehensive system is a challenging task. Previously, we developed a literature-based dynamic simulation model, which included transcriptional regulation, transcription, translation, and enzymatic reactions related to glycolysis, the pentose phosphate pathway, the tricarboxylic acid (TCA) cycle, and the anaplerotic pathway of Escherichia coli. During simulation, cell growth was defined such as to reproduce the experimental...

Postreplication repair gap filling in an Escherichia coli strain deficient in dnaB gene product

International Nuclear Information System (INIS)

Johnson, R.C.

1975-01-01

Gaps in daughter-strand DNA synthesized after exposure of Escherichia coli E279 to ultraviolet light are filled during reincubation at 30 0 C for 20 min. Escherichia coli E279 is phenotypically DnaB - when incubated at 43 0 C. Cells incubated at 43 0 C were tested for their ability to complete postreplication repair gap filling. It is concluded that the dnaB gene product is essential for postreplication repair gap filling and that the inhibition seen is not initially the result of degradation

Seroprevalence of Escherichia coli in traditional cheeses manufactured in Maragheh rural

Directory of Open Access Journals (Sweden)

S Mahdavi

2014-11-01

Full Text Available Coliforms and Escherichia coli are major microbial indicators in the accessing the quality of foodstuffs. The presence of these bacteria in foods is considered as an indication of fecal contamination. E. coli O157:H7 is the most pathogenic strain that is transmitted to human through animal-foods. This study was performed on 100 traditional cheese samples manufactured in Maragheh rural to determine the seroprevalence of E. coli. The samples were analyzed with standard microbiological methods followed by biochemical confirmatory tests. Afterwards, the isolates were assayed for the detection of O-serotypes using direct agglutination method. Among the 100 cheese samples, E. coli O157serotypewas not detected in any sample. However, other E. coli serotypes including 32 isolates of non-O157 serotypes were detected. Among the isolates, enteropathogenic, enterotoxigenic and enterohaemorhhagic serogruops was also detected.

A PCR procedure for the detection of Giardia intestinalis cysts and Escherichia coli in lettuce.

Science.gov (United States)

Ramirez-Martinez, M L; Olmos-Ortiz, L M; Barajas-Mendiola, M A; Giono Cerezo, S; Avila, E E; Cuellar-Mata, P

2015-06-01

Giardia intestinalis is a pathogen associated with foodborne outbreaks and Escherichia coli is commonly used as a marker of faecal contamination. Implementation of routine identification methods of G. intestinalis is difficult for the analysis of vegetables and the microbiological detection of E. coli requires several days. This study proposes a PCR-based assay for the detection of E. coli and G. intestinalis cysts using crude DNA isolated from artificially contaminated lettuce. The G. intestinalis and E. coli PCR assays targeted the β-giardin and uidA genes, respectively, and were 100% specific. Forty lettuces from local markets were analysed by both PCR and light microscopy and no cysts were detected, the calculated detection limit was 20 cysts per gram of lettuce; however, by PCR, E. coli was detected in eight of ten randomly selected samples of lettuce. These data highlight the need to validate procedures for routine quality assurance. These PCR-based assays can be employed as alternative methods for the detection of G. intestinalis and E. coli and have the potential to allow for the automation and simultaneous detection of protozoa and bacterial pathogens in multiple samples. Significance and impact of the study: There are few studies for Giardia intestinalis detection in food because methods for its identification are difficult for routine implementation. Here, we developed a PCR-based method as an alternative to the direct observation of cysts in lettuce by light microscopy. Additionally, Escherichia coli was detected by PCR and the sanitary quality of lettuce was evaluated using molecular and standard microbiological methods. Using PCR, the detection probability of Giardia cysts inoculated onto samples of lettuce was improved compared to light microscopy, with the advantage of easy automation. These methods may be employed to perform timely and affordable detection of foodborne pathogens. © 2015 The Society for Applied Microbiology.

Evaluation of the efficacy of an autogenous Escherichia coli vaccine in broiler breeders

DEFF Research Database (Denmark)

Li, Lili; Thøfner, Ida; Christensen, Jens Peter

2017-01-01

vaccine in broiler breeders. Three groups of 28 weeks old broiler breeders (unvaccinated, vaccinated once and twice, respectively) were challenged with a homologous E. coli strain (same strain as included in the vaccine) or a heterologous challenge strain in an experimental ascending model. The clinical...... infection, significant protection of an autogenous E. coli vaccine against neither a homologous nor a heterologous E. coli challenge could not be documented.......In poultry production Escherichia coli autogenous vaccines are often used. However, the efficacy of autogenous E. coli vaccinations has not been evaluated experimentally in chickens after start of lay. The aim of the present study was to evaluate the protective effect of an autogenous E. coli...

The incidence and antibiotics susceptibility of Escherichia coli O157 ...

African Journals Online (AJOL)

STORAGESEVER

2010-02-22

Feb 22, 2010 ... The incidence of Escherichia coli 0157: H7 was assessed in meat samples from slaughtered cattle in. Ibadan metropolis by culturing ... high quality farm to fork wholesome and safe meat for public consumption in Nigeria. Key words: EHEC .... Prevalence and in vitro antimicrobial susceptibility. Trop. Vet. 26.

Budget analysis of Escherichia coli at a southern Lake Michigan Beach

Science.gov (United States)

Thupaki, P.; Phanikumar, M.S.; Beletsky, D.; Schwab, D.J.; Nevers, M.B.; Whitman, R.L.

2010-01-01

Escherichia coli (EC) concentrations at two beaches impacted by river plume dynamics in southern Lake Michigan were analyzed using three-dimensional hydrodynamic and transport models. The relative importance of various physical and biological processes influencing the fate and transport of EC were examined via budget analysis and a first-order sensitivity analysis of model parameters. The along-shore advective fluxofEC(CFU/m2·s)was found to be higher compared to its crossshore counterpart; however, the sum of diffusive and advective components was of a comparable magnitude in both directions showing the importance of cross-shore exchange in EC transport. Examination of individual terms in the EC mass balance equation showed that vertical turbulent mixing in the water column dominated the overall EC transport for the summer conditions simulated. Dilution due to advection and diffusion accounted for a large portion of the total EC budget in the nearshore, and the net EC loss rate within the water column (CFU/m3·s) was an order of magnitude smaller compared to the horizontal and vertical transport rates. This result has important implications for modeling EC at recreational beaches; however, the assessment of the magnitude of EC loss rate is complicated due to the strong coupling between vertical exchange and depth-dependent EC loss processes such as sunlight inactivation and settling. Sensitivity analysis indicated that solar inactivation has the greatest impact on EC loss rates. Although these results are site-specific, they clearly bring out the relative importance of various processes involved.

Expression of maize prolamins in Escherichia Coli

International Nuclear Information System (INIS)

Wang, Szu-zhen; Esen, Asim

1985-01-01

We have constructed a cDNA expression library of developing corn (Zea manys L.) endosperm using plasmid pUC8 as vector and Escherichia coli strain DH1 as host. The expression library was screened with non-radioactive immunological probes to detect the expression of gamma-zein and alpha-zein. When anti-gamma-zein antibody was used as the probe, 23 colonies gave positive reactions. The lengths of cDNA inserts of the 23 colonies were found to be 250-900 base pairs. When anti-alpha zein antibody was used, however, fewer colonies gave positive reactions. The library was also screened by colony-hybridization with 32 P-labeled DNA probes. Based on immunological and hybridization screening of the library and other evidence, we conclude that alpha-zein was either toxic to E. coli cells or rapidly degraded whereas gamma-zein and its fragments were readily expressed. (author)

Consequences of concurrent Ascaridia galli and Escherichia coli infections in chickens

Directory of Open Access Journals (Sweden)

Permin A

2006-03-01

Full Text Available Three experiments were carried out to examine the consequences of concurrent infections with Ascaridia galli and Escherichia coli in chickens raised for table egg production. Characteristic pathological lesions including airsacculitis, peritonitis and/or polyserositis were seen in all groups infected with E. coli. Furthermore, a trend for increased mortality rates was observed in groups infected with both organisms which, however, could not be confirmed statistically. The mean worm burden was significantly lower in combined infection groups compared to groups infected only with A. galli. It was also shown that combined infections of E. coli and A. galli had an added significant negative impact on weight gain.

Development of a multiplex real-time PCR assay for phylogenetic analysis of Uropathogenic Escherichia coli.

Science.gov (United States)

Hasanpour, Mojtaba; Najafi, Akram

2017-06-01

Uropathogenic Escherichia coli (UPEC) is among major pathogens causing 80-90% of all episodes of urinary tract infections (UTIs). Recently, E. coli strains are divided into eight main phylogenetic groups including A, B1, B2, C, D, E, F, and clade I. This study was aimed to develop a rapid, sensitive, and specific multiplex real time PCR method capable of detecting phylogenetic groups of E. coli strains. This study was carried out on E. coli strains (isolated from the patient with UTI) in which the presence of all seven target genes had been confirmed in our previous phylogenetic study. An EvaGreen-based singleplex and multiplex real-time PCR with melting curve analysis was designed for simultaneous detection and differentiation of these genes. The primers were selected mainly based on the production of amplicons with melting temperatures (T m ) ranging from 82°C to 93°C and temperature difference of more than 1.5°C between each peak.The multiplex real-time PCR assays that have been developed in the present study were successful in detecting the eight main phylogenetic groups. Seven distinct melting peaks were discriminated, with Tm value of 93±0.8 for arpA, 89.2±0.1for chuA, 86.5±0.1 for yjaA, 82.3±0.2 for TspE4C2, 87.8±0.1for trpAgpC, 85.4±0.6 for arpAgpE genes, and 91±0.5 for the internal control. To our knowledge, this study is the first melting curve-based real-time PCR assay developed for simultaneous and discrete detection of these seven target genes. Our findings showed that this assay has the potential to be a rapid, reliable and cost-effective alternative for routine phylotyping of E. coli strains. Copyright © 2017 Elsevier B.V. All rights reserved.

GenoBase: comprehensive resource database of Escherichia coli K-12.

Science.gov (United States)

Otsuka, Yuta; Muto, Ai; Takeuchi, Rikiya; Okada, Chihiro; Ishikawa, Motokazu; Nakamura, Koichiro; Yamamoto, Natsuko; Dose, Hitomi; Nakahigashi, Kenji; Tanishima, Shigeki; Suharnan, Sivasundaram; Nomura, Wataru; Nakayashiki, Toru; Aref, Walid G; Bochner, Barry R; Conway, Tyrrell; Gribskov, Michael; Kihara, Daisuke; Rudd, Kenneth E; Tohsato, Yukako; Wanner, Barry L; Mori, Hirotada

2015-01-01

Comprehensive experimental resources, such as ORFeome clone libraries and deletion mutant collections, are fundamental tools for elucidation of gene function. Data sets by omics analysis using these resources provide key information for functional analysis, modeling and simulation both in individual and systematic approaches. With the long-term goal of complete understanding of a cell, we have over the past decade created a variety of clone and mutant sets for functional genomics studies of Escherichia coli K-12. We have made these experimental resources freely available to the academic community worldwide. Accordingly, these resources have now been used in numerous investigations of a multitude of cell processes. Quality control is extremely important for evaluating results generated by these resources. Because the annotation has been changed since 2005, which we originally used for the construction, we have updated these genomic resources accordingly. Here, we describe GenoBase (http://ecoli.naist.jp/GB/), which contains key information about comprehensive experimental resources of E. coli K-12, their quality control and several omics data sets generated using these resources. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Escherichia coli and coliforms level of food utensils at food premises in Kuala Pilah, Malaysia

Science.gov (United States)

Saipullizan, Siti Nurul Ain; Mutalib, Sahilah Abd.; Sedek, Razalee

2018-04-01

The aim of this study was to evaluate the Escherichia coli and coliforms level of food utensils at sixty food premises in Kuala Pilah, Malaysia. The swab technique was used to investigate the presence of E. coli and coliforms on 180 of food utensils (chopping boards: 60, knives: 60 and dish plates: 60). The results indicated that 180 of food utensils were contaminated with E. coli and coliforms. More than 60% of the coliforms were exceeded the acceptable limit compared to E. coli on the food utensils. The one-way ANOVA analysis demonstrated that the presence of E. coli and coliforms differed significantly among the three types of food utensils (knives, chopping boards, and dish plates). In conclusion, this study revealed that there are hygiene issues exist in every food premises. The food utensils are safe to use during the food preparation if the presence of E. coli and coliforms are not exceed the acceptable limit. Thus, it is recommended that the food handlers in the food premises should improve effective cleaning and sanitizing of food utensils in their daily work.

Synthesis of avenanthramides using engineered Escherichia coli.

Science.gov (United States)

Lee, Su Jin; Sim, Geun Young; Kang, Hyunook; Yeo, Won Seok; Kim, Bong-Gyu; Ahn, Joong-Hoon

2018-03-22

Hydroxycinnamoyl anthranilates, also known as avenanthramides (avns), are a group of phenolic alkaloids with anti-inflammatory, antioxidant, anti-itch, anti-irritant, and antiatherogenic activities. Some avenanthramides (avn A-H and avn K) are conjugates of hydroxycinnamic acids (HC), including p-coumaric acid, caffeic acid, and ferulic acid, and anthranilate derivatives, including anthranilate, 4-hydroxyanthranilate, and 5-hydroxyanthranilate. Avns are primarily found in oat grain, in which they were originally designated as phytoalexins. Knowledge of the avns biosynthesis pathway has now made it possible to synthesize avns through a genetic engineering strategy, which would help to further elucidate their properties and exploit their beneficial biological activities. The aim of the present study was to synthesize natural avns in Escherichia coli to serve as a valuable resource. We synthesized nine avns in E. coli. We first synthesized avn D from glucose in E. coli harboring tyrosine ammonia lyase (TAL), 4-coumarate:coenzyme A ligase (4CL), anthranilate N-hydroxycinnamoyl/benzoyltransferase (HCBT), and anthranilate synthase (trpEG). A trpD deletion mutant was used to increase the amount of anthranilate in E. coli. After optimizing the incubation temperature and cell density, approximately 317.2 mg/L of avn D was synthesized. Avn E and avn F were then synthesized from avn D, using either E. coli harboring HpaBC and SOMT9 or E. coli harboring HapBC alone, respectively. Avn A and avn G were synthesized by feeding 5-hydroxyanthranilate or 4-hydroxyanthranilate to E. coli harboring TAL, 4CL, and HCBT. Avn B, avn C, avn H, and avn K were synthesized from avn A or avn G, using the same approach employed for the synthesis of avn E and avn F from avn D. Using different HCs, nine avns were synthesized, three of which (avn D, avn E, and avn F) were synthesized from glucose in E. coli. These diverse avns provide a strategy to synthesize both natural and unnatural avns

Proofreading in vivo: Editing of homocysteine by methionyl-tRNA synthetase in Escherichia coli

International Nuclear Information System (INIS)

Jakubowski, H.

1990-01-01

Previous in vitro studies have established a pre-transfer proofreading mechanism for editing of homocysteine by bacterial methionyl-, isoleucyl-, and valyl-tRNA synthetases. The unusual feature of the editing is the formation of a distinct compound, homocysteine thiolactone. Now, two-dimensional TLC analysis of 35S-labeled amino acids extracted from cultures of the bacterium Escherichia coli reveals that the thiolactone is also synthesized in vivo. In E. coli, the thiolactone is made from homocysteine in a reaction catalyzed by methionyl-tRNA synthetase. One molecule of homocysteine is edited as thiolactone per 109 molecules of methionine incorporated into protein in vivo. These results not only directly demonstrate that the adenylate proofreading pathway for rejection of misactivated homocysteine operates in vivo in E. coli but, in general, establish the importance of error-editing mechanisms in living cells

Inactivation and Gene Expression of a Virulent WastewaterEscherichia coliStrain and the Nonvirulent CommensalEscherichia coliDSM1103 Strain upon Solar Irradiation

KAUST Repository

Aljassim, Nada I.; Mantilla-Calderon, David; Wang, Tiannyu; Hong, Pei-Ying

2017-01-01

This study examined the decay kinetics and molecular responses of two Escherichia coli strains upon solar irradiation. The first is E. coli PI-7, a virulent and antibiotic-resistant strain that was isolated from wastewater and carries the emerging NDM-1 antibiotic resistance gene. The other strain, E. coli DSM1103, displayed lower virulence and antibiotic resistance than E. coli PI-7. In a buffer solution, E. coli PI-7 displayed a longer lag phase prior to decay and a longer half-life compared with E. coli DSM1103 (6.64 ± 0.63 h and 2.85 ± 0.46 min vs 1.33 ± 0.52 h and 2.04 ± 0.36 min). In wastewater, both E. coli strains decayed slower than they did in buffer. Although solar irradiation remained effective in reducing the numbers of both strains by more than 5-log10 in <24 h, comparative genomics and transcriptomics revealed differences in the genomes and overall regulation of genes between the two E. coli strains. A wider arsenal of genes related to oxidative stress, cellular repair and protective mechanisms were upregulated in E. coli PI-7. Subpopulations of E. coli PI-7 expressed genes related to dormancy and persister cell formation during the late decay phase, which may have accounted for its prolonged persistence. Upon prolonged solar irradiation, both E. coli strains displayed upregulation of genes related to horizontal gene transfer and antibiotic resistance. Virulence functions unique to E. coli PI-7 were also upregulated. Our findings collectively indicated that, whereas solar irradiation is able to reduce total cell numbers, viable E. coli remained and expressed genes that enable survival despite solar treatment. There remains a need for heightened levels of concern regarding risks arising from the dissemination of E. coli that may remain viable in wastewater after solar irradiation.

Inactivation and Gene Expression of a Virulent WastewaterEscherichia coliStrain and the Nonvirulent CommensalEscherichia coliDSM1103 Strain upon Solar Irradiation

KAUST Repository

Aljassim, Nada I.

2017-03-06

This study examined the decay kinetics and molecular responses of two Escherichia coli strains upon solar irradiation. The first is E. coli PI-7, a virulent and antibiotic-resistant strain that was isolated from wastewater and carries the emerging NDM-1 antibiotic resistance gene. The other strain, E. coli DSM1103, displayed lower virulence and antibiotic resistance than E. coli PI-7. In a buffer solution, E. coli PI-7 displayed a longer lag phase prior to decay and a longer half-life compared with E. coli DSM1103 (6.64 ± 0.63 h and 2.85 ± 0.46 min vs 1.33 ± 0.52 h and 2.04 ± 0.36 min). In wastewater, both E. coli strains decayed slower than they did in buffer. Although solar irradiation remained effective in reducing the numbers of both strains by more than 5-log10 in <24 h, comparative genomics and transcriptomics revealed differences in the genomes and overall regulation of genes between the two E. coli strains. A wider arsenal of genes related to oxidative stress, cellular repair and protective mechanisms were upregulated in E. coli PI-7. Subpopulations of E. coli PI-7 expressed genes related to dormancy and persister cell formation during the late decay phase, which may have accounted for its prolonged persistence. Upon prolonged solar irradiation, both E. coli strains displayed upregulation of genes related to horizontal gene transfer and antibiotic resistance. Virulence functions unique to E. coli PI-7 were also upregulated. Our findings collectively indicated that, whereas solar irradiation is able to reduce total cell numbers, viable E. coli remained and expressed genes that enable survival despite solar treatment. There remains a need for heightened levels of concern regarding risks arising from the dissemination of E. coli that may remain viable in wastewater after solar irradiation.

Comparative Genomic Analysis of Globally Dominant ST131 Clone with Other Epidemiologically Successful Extraintestinal Pathogenic Escherichia coli (ExPEC Lineages

Directory of Open Access Journals (Sweden)

Sabiha Shaik

2017-10-01

Full Text Available Escherichia coli sequence type 131 (ST131, a pandemic clone responsible for the high incidence of extraintestinal pathogenic E. coli (ExPEC infections, has been known widely for its contribution to the worldwide dissemination of multidrug resistance. Although other ExPEC-associated and extended-spectrum-β-lactamase (ESBL-producing E. coli clones, such as ST38, ST405, and ST648 have been studied widely, no comparative genomic data with respect to other genotypes exist for ST131. In this study, comparative genomic analysis was performed for 99 ST131 E. coli strains with 40 genomes from three other STs, including ST38 (n = 12, ST405 (n = 10, and ST648 (n = 18, and functional studies were performed on five in-house strains corresponding to the four STs. Phylogenomic analysis results from this study corroborated with the sequence type-specific clonality. Results from the genome-wide resistance profiling confirmed that all strains were inherently multidrug resistant. ST131 genomes showed unique virulence profiles, and analysis of mobile genetic elements and their associated methyltransferases (MTases has revealed that several of them were missing from the majority of the non-ST131 strains. Despite the fact that non-ST131 strains lacked few essential genes belonging to the serum resistome, the in-house strains representing all four STs demonstrated similar resistance levels to serum antibactericidal activity. Core genome analysis data revealed that non-ST131 strains usually lacked several ST131-defined genomic coordinates, and a significant number of genes were missing from the core of the ST131 genomes. Data from this study reinforce adaptive diversification of E. coli strains belonging to the ST131 lineage and provide new insights into the molecular mechanisms underlying clonal diversification of the ST131 lineage.

Brote causado por Escherichia coli en Chalco, México Outbreak caused by Escherichia coli in Chalco, México

Directory of Open Access Journals (Sweden)

Iliana Alejandra Cortés-Ortiz

2002-07-01

Full Text Available Objetivo. Identificar el agente causal del brote de diarrea asociado con el desbordamiento del canal de aguas negras en Chalco. Material y métodos. Estudio retrospectivo y transversal, efectuado en el Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, de la Secretaría de Salud, con 1 550 hisopos rectales para el aislamiento e identificación bioquímica de V. cholerae y enterobacterias, obtenidos de la población del Valle de Chalco, que presentó diarrea y vómito durante el desastre natural acontecido el 31 de mayo de 2000. El análisis de los resultados se efectuó por la diferencia entre las proporciones de dos poblaciones (prueba de Ji cuadrada. Las cepas de E. coli se hibridaron por "colony blot" para los grupos ETEC, EIEC, EPEC y EHEC. Resultados. El 0.45% correspondió a Salmonella: S. agona, S. infantis, S. enteritidis, S. muenchen, S. typhimurium; 0.06% a Shigella flexneri 3a, y 76.6% a E. coli: 62.2% a ETEC (44.6 % con LT, 11.2% con ST, y 44.1% con ambas sondas, 0.84% a EIEC (sonda ial, 0.84% a EPEC (sonda bundle-forming pilus BFP, 0.08% a E. coli enterohemorrágica no-O157:H7 (sonda pCVD419, y 36.02% no hibridó. No se encontró asociación entre E. coli patógena con la edad y género. Conclusiones. Escherichia coli podría ser responsable del brote de diarrea. Es importante conocer el agente etiológico del brote para encaminar las estrategias en el estudio y control sanitario del mismo.Objective. To identify the etiologic agent responsible for a disease outbreak following an overflow of sewage water in Valle de Chalco, Mexico. Material and Methods. A retrospective cross-sectional study was carried out. Rectal samples were collected from the population of Chalco valley, who suffered from diarrhea and vomiting during a natural disaster that took place on May 31, 2000. The Instituto de Diagnóstico y Referencia Epidemiológicos (Epidemic Reference and Diagnosis Institute, InDRE, Ministry of Health, received 1521 rectal

Recombination Blurs Phylogenetic Groups Routine Assignment in Escherichia coli: Setting the Record Straight

Science.gov (United States)

Turrientes, María-Carmen; González-Alba, José-María; del Campo, Rosa; Baquero, María-Rosario; Cantón, Rafael; Baquero, Fernando; Galán, Juan Carlos

2014-01-01

The characterization of population structures plays a main role for understanding outbreaks and the dynamics of bacterial spreading. In Escherichia coli, the widely used combination of multiplex-PCR scheme together with goeBURST has some limitations. The purpose of this study is to show that the combination of different phylogenetic approaches based on concatenated sequences of MLST genes results in a more precise assignment of E. coli phylogenetic groups, complete understanding of population structure and reconstruction of ancestral clones. A collection of 80 Escherichia coli strains of different origins was analyzed following the Clermont and Doumith's multiplex-PCR schemes. Doumith's multiplex-PCR showed only 1.7% of misassignment, whereas Clermont's-2000 protocol reached 14.0%, although the discrepancies reached 30% and 38.7% respectively when recombinant C, F and E phylogroups were considered. Therefore, correct phylogroup attribution is highly variable and depends on the clonal composition of the sample. As far as population structure of these E. coli strains, including 48 E. coli genomes from GenBank, goeBURST provides a quite dispersed population structure; whereas NeighborNet approach reveals a complex population structure. MLST-based eBURST can infer different founder genotypes, for instance ST23/ST88 could be detected as the founder genotypes for STC23; however, phylogenetic reconstructions might suggest ST410 as the ancestor clone and several evolutionary trajectories with different founders. To improve our routine understanding of E. coli molecular epidemiology, we propose a strategy based on three successive steps; first, to discriminate three main groups A/B1/C, D/F/E and B2 following Doumith's protocol; second, visualization of population structure based on MLST genes according to goeBURST, using NeighborNet to establish more complex relationships among STs; and third, to perform, a cost-free characterization of evolutionary trajectories in variants

In vitro Clostridium perfringens and Escherichia coli toxin adsorption of Varium

Science.gov (United States)

Enteric disease agents, such as Clostridium perfringens and Escherichia coli, produce detrimental biotoxins that cause significant economic loss annually in the poultry industry. The objective of this study was to determine the in vitro biotoxin adsorption capability of Varium. An enzyme-linked im...

Primer aislamiento de Escherichia coli O157:H7 Enterohemorrágica en el Perú

Directory of Open Access Journals (Sweden)

Blanca Huapaya C

2001-01-01

Full Text Available En Febrero del año 2001 como parte del "Estudio transversal de los agentes etiológicos de diarrea aguda" en la Macrorregión Sur del país, el Laboratorio Referencial de Tacna aisló una cepa procedente de una muestra de heces de un lactante de 11 meses de edad con un cuadro de diarrea disentérica, identificándola como Escherichia coli O157. Esta cepa fue confirmada y caracterizada en el Instituto Nacional de Salud como E. coli O157:H7 toxina shiga tipo II, siendo el primer aislamiento reportado de Escherichia coli enterohemorrágica en el Perú.

POTENSI RUMPUT LAUT DI PANTAI BAYAH, KABUPATEN LEBAK, BANTEN SEBAGAI ANTIBAKTERI Escherichia coli

Directory of Open Access Journals (Sweden)

Triastinurmiatiningsih Triastinurmiatiningsih

2008-07-01

Full Text Available Antibacterial potency of some seaweed against Escherichia coli has been known. The aim of this research is to know the species of seaweeds from Bayah beach Lebak Banten which may be used as antibacterial against Escherichia coli. Twenty one seaweed species samples from Bayah Beach Lebak Banten were exstracted by organic solvent of absolute methanol according to Espeche, Fraile, and Mayer (1984 and Darusman, Sayuti, Komar & Pamungkas (1992 methods. The antibacterial activities were examined by means of Kirby-Bauer or diffusion method. The results showed antibacterial activities occur from the extract of Boodlea composite, Chaetomorpha crassa, Ulva fasciata, Sargassum crustaefolium, Padina australis and Halimeda gracilis. Sofar, Padina australis extract had shown better inhibitory activities than others.

Epithelial Cell Adherence Mediated by the Enterotoxigenic Escherichia coli Tia Protein

OpenAIRE

Mammarappallil, Joseph G.; Elsinghorst, Eric A.

2000-01-01

In vitro studies have shown that enterotoxigenic Escherichia coli (ETEC) strains are capable of invading cultured epithelial cells derived from the human ileum and colon. Two separate invasion loci (tia and tib) have previously been isolated from the classical ETEC strain H10407. The tia locus has been shown to direct the synthesis of Tia, a 25-kDa outer membrane protein. Tia is sufficient to confer the adherence and invasion phenotypes on laboratory stains of E. coli, suggesting that this pr...

Molecular relatedness of ESBL/AmpC-producing Escherichia coli from humans, animals, food and the environment : a pooled analysis

NARCIS (Netherlands)

Dorado-García, Alejandro|info:eu-repo/dai/nl/372621023; Smid, Joost H|info:eu-repo/dai/nl/313996458; van Pelt, Wilfrid; Bonten, Marc J M; Fluit, Ad C; van den Bunt, Gerrita; Wagenaar, Jaap A|info:eu-repo/dai/nl/126613354; Hordijk, Joost|info:eu-repo/dai/nl/314839542; Dierikx, Cindy M; Veldman, Kees T; de Koeijer, Aline; Dohmen, Wietske|info:eu-repo/dai/nl/333690451; Schmitt, Heike|info:eu-repo/dai/nl/304831042; Liakopoulos, Apostolos; Pacholewicz, Ewa; Lam, Theo J G M|info:eu-repo/dai/nl/14686820X; Velthuis, Annet G J; Heuvelink, Annet; Gonggrijp, Maaike A; van Duijkeren, Engeline; van Hoek, Angela H A M; de Roda Husman, Ana Maria|info:eu-repo/dai/nl/139498281; Blaak, Hetty; Havelaar, Arie H|info:eu-repo/dai/nl/072306122; Mevius, Dik J|info:eu-repo/dai/nl/079677347; Heederik, Dick J J|info:eu-repo/dai/nl/072910542

Background: In recent years, ESBL/AmpC-producing Escherichia coli (ESBL/AmpC-EC) have been isolated with increasing frequency from animals, food, environmental sources and humans. With incomplete and scattered evidence, the contribution to the human carriage burden from these reservoirs remains

MOLECULAR-PHYLOGENETIC CHARACTERIZATION AND ANTIMICROBIAL RESISTANCE OF Escherichia coli ISOLATED FROM GOATS WITH DIARRHEA

Directory of Open Access Journals (Sweden)

Rodrigo Almeida Guimarães

2015-10-01

Full Text Available Neonatal diarrhea determines significant changes in feed conversion, causing productivity loss in caprine herds. The antimicrobial resistance in bacteria is characterized as an important public health issue; therefore, Escherichia coli may be characterized as an important pathogen due to expressing virulence mechanisms responsible for significant clinical conditions in humans and animals. The present study evaluated the presence of E. coli among 117 caprine fecal samples and analyzed the isolates for antimicrobial resistance. Suggestive colonies were submitted to biochemical screening followed by genotypic group determination and phylogenetic analysis; further, the samples were submitted to antimicrobials susceptibility test. E. coli, Salmonella spp, Shigella sonnei and Enterobacter aerogenes were identified. E. coli isolates were phylogenetically classified as B2 (9/39, D (19/39, B1 (7/39 e A (4/29 groups. The analysis of the isolates also revealed the presence of K99 (04/39 and Stx (02/39 virulence factors. Antimicrobial susceptibility test revealed sensitive isolates to Chloramphenicol, Streptomycin, Amoxicillin and Ciprofloxacin, being all resistant to Lincomycin, Vancomycin and Penicillin. The results support the need of establishing restricted protocols for antimicrobial use, a fundamental procedure for health improvement in Brazilian caprine herds.

Damage-induced DNA repair processes in Escherichia coli cells

International Nuclear Information System (INIS)

Slezarikova, V.

1986-01-01

The existing knowledge is summed up of the response of Escherichia coli cells to DNA damage due to various factors including ultraviolet radiation. So far, three inducible mechanisms caused by DNA damage are known, viz., SOS induction, adaptation and thermal shock induction. Greatest attention is devoted to SOS induction. Its mechanism is described and the importance of the lexA recA proteins is shown. In addition, direct or indirect role is played by other proteins, such as the ssb protein binding the single-strand DNA sections. The results are reported of a study of induced repair processes in Escherichia coli cells repeatedly irradiated with UV radiation. A model of induction by repeated cell irradiation discovered a new role of induced proteins, i.e., the elimination of alkali-labile points in the daughter DNA synthetized on a damaged model. The nature of the alkali-labile points has so far been unclear. In the adaptation process, regulation proteins are synthetized whose production is induced by the presence of alkylation agents. In the thermal shock induction, new proteins synthetize in cells, whose function has not yet been clarified. (E.S.)

Effects of low-frequency magnetic fields on bacteria Escherichia coli

Czech Academy of Sciences Publication Activity Database

Strašák, Luděk; Vetterl, Vladimír; Šmarda, J.

2002-01-01

Roč. 55, 1/2 (2002), s. 161-164 ISSN 1567-5394 R&D Projects: GA ČR GA310/01/0816; GA AV ČR IBS5004107 Institutional research plan: CEZ:AV0Z5004920 Keywords : ELF magnetic fields * Escherichia coli * exposure Subject RIV: BO - Biophysics Impact factor: 1.463, year: 2002

Peptidoglycan Hydrolases of Escherichia coli

Science.gov (United States)

van Heijenoort, Jean

2011-01-01

Summary: The review summarizes the abundant information on the 35 identified peptidoglycan (PG) hydrolases of Escherichia coli classified into 12 distinct families, including mainly glycosidases, peptidases, and amidases. An attempt is also made to critically assess their functions in PG maturation, turnover, elongation, septation, and recycling as well as in cell autolysis. There is at least one hydrolytic activity for each bond linking PG components, and most hydrolase genes were identified. Few hydrolases appear to be individually essential. The crystal structures and reaction mechanisms of certain hydrolases having defined functions were investigated. However, our knowledge of the biochemical properties of most hydrolases still remains fragmentary, and that of their cellular functions remains elusive. Owing to redundancy, PG hydrolases far outnumber the enzymes of PG biosynthesis. The presence of the two sets of enzymes acting on the PG bonds raises the question of their functional correlations. It is difficult to understand why E. coli keeps such a large set of PG hydrolases. The subtle differences in substrate specificities between the isoenzymes of each family certainly reflect a variety of as-yet-unidentified physiological functions. Their study will be a far more difficult challenge than that of the steps of the PG biosynthesis pathway. PMID:22126997

Cadmium tolerance and antibiotic resistance in Escherichia coli isolated from waste stabilization ponds.

Science.gov (United States)

Patra, Sova; Das, T K; Avila, C; Cabello, V; Castillo, F; Sarkar, D; Lahiri, Susmita; Jana, B B

2012-04-01

The incidence pattern of cadmium tolerance and antibiotics resistance by Escherichia coli was examined periodically from the samples of water, sludge and intestine of fish raised in waste stabilization ponds in a sewage treatment plant. Samples of water and sludge were collected from all the selected ponds and were monitored for total counts of fecal coliform (FC), total coliform (TC) and the population of Escherichia coli, which was also obtained from the intestine of fishes. Total counts of both FC and TC as well as counts of E. coli were markedly reduced from the facultative pond to the last maturation pond. Tolerance limit to cadmium by E. coli tended to decline as the distance of the sewage effluent from the source increased; the effective lethal concentration of cadmium ranged from 0.1 mM in split chamber to 0.05 mM in first maturation pond. E. coli isolated from water, sludge and fish gut were sensitive to seven out of ten antibiotics tested. It appears that holistic functions mediated through the mutualistic growth of micro algae and heterotrophic bacteria in the waste stabilization ponds were responsible for the promotion of water quality and significant reduction of coliform along the sewage effluent gradient.

Escherichia coli pathotypes in Pakistan from consecutive floods in 2010 and 2011.

Science.gov (United States)

Bokhari, Habib; Shah, Muhammad Ali; Asad, Saba; Akhtar, Sania; Akram, Muhammad; Wren, Brendan W

2013-03-01

This study compares Escherichia coli pathotypes circulating among children in Pakistan during the floods of 2010 and 2011 and from sporadic cases outside flood affected areas. Using multiplex polymerase chain reaction 115 of 205 stool samples (56.29%) were positive for diarrheagenic E. coli from specimens taken during the floods compared with 50 of 400 (12.5%) stool samples being positive for sporadic cases. The E. coli pathotypes were categorized as Enteropathogenic E. coli 33 (28.69%) and 13 (26%), Enterotoxigenic E. coli 29 (25.21%) and 15 (30%), Enteroaggregative E. coli 21 (18.2%) and 18 (36%), Enterohemorrhagic E. coli 5 (4.34%) and 1 (2%) from flood and sporadic cases, respectively. Furthermore, patients co-infected with more than one pathotype were 26 (22.60%) and 3 (6%) from flood and sporadic cases, respectively. The study shows an unexpectedly high rate of isolation of E. coli pathotypes suggesting Pakistan as an endemic region that requires active surveillance particularly during flood periods.

Incidence of temonera, sulphuhydryl variables and cefotaximase genes associated with ?-lactamase producing escherichia coli in clinical isolates

OpenAIRE

Isaiah, Ibeh Nnana; Nche, Bikwe Thomas; Nwagu, Ibeh Georgina; Nwagu, Ibeh Isaiah

2011-01-01

Background: The occurrence of the different types of Extended spectrum beta Lactamase producing Escherichia coli with the, Sulphurhydryl variable, Temonera and the Cefotaximase have been on the rise Aim: The study was to determine the prevalence of extended spectrum beta lactamase gene resistance across the clinical isolates of hospitalized patients. Materials and Method: Three hundred and fifty isolates of Escherichia coli were received from different clinical specimens. The susceptibility p...

Two proline porters in Escherichia coli K-12.

Science.gov (United States)

Stalmach, M E; Grothe, S; Wood, J M

1983-11-01

Escherichia coli mutants defective at putP and putA lack proline transport via proline porter I and proline dehydrogenase activity, respectively. They retain a proline uptake system (proline porter II) that is induced during tryptophan-limited growth and are sensitive to the toxic L-proline analog, 3,4-dehydroproline. 3,4-Dehydroproline-resistant mutants derived from a putP putA mutant lack proline porter II. Auxotrophic derivatives derived from putP+ or putP bacteria can grow if provided with proline at low concentration (25 microM); those derived from the 3,4-dehydroproline-resistant mutants require high proline for growth (2.5 mM). We conclude that E. coli, like Salmonella typhimurium, possesses a second proline porter that is inactivated by mutations at the proP locus.

Estudo da Atividade Antimicrobiana das Folhas de Jatrophacurcas L. frente ao Staphylococcus aureus e Escherichia coli/ Study of Antimicrobial Activity of Leave of Jatropha curcas L. against Staphylococcus aureus and Escherichia coli

Directory of Open Access Journals (Sweden)

Amanda Venturini Arantes

2013-06-01

Farland in sterile saline solution. This was followed by incubation in an oven at 35°C temperature for 24h. Then development was performed by adding 20 µl Chloride Triphenyl Tetrezólico and analysis of results for staining. In each plate it was made a positive and a negative control. Results: There was a microbial growth inhibitory effect of S. aureus and E. coli before extracts of Jatropha curcas L. at concentrations of 50mg to 200mg. That is, at the concentration of 25mg no inhibitory effect on E. coli and S. aureus. Conclusion: The crude extract of Jatropha curcas L. showed inhibitory activity against the growth of colonies of Staphylococcus aureus and Escherichia coli isolated from patients at a university hospital in southern Minas Gerais in the concentrations 50, 75, 100, 125, 150, 175 and 200mg/ml.

Adaptation mechanisms of Escherichia Coli to the ultraviolet light I. Isolation of mutants resistant to ultraviolet light; Mecanismos de adaptacion de Escherichia Coli a la luz ultravioleta I. Aislamiento de mutantes resistentes a luz ultravioleta

Energy Technology Data Exchange (ETDEWEB)

Alcantara D, D [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

1995-09-15

The objective of this work is to study the adaptation mechanisms of Escherichia coli to the ultraviolet light of 254 nm (W), a component of the solar light that induces a variety of damages in the DNA of the cells exposed, which should be eliminated in order to avoid its lethal and mutagenic effects. Inside this first report, the results obtained about the resistance to UV radiation of 5 independent populations of Escherichia coli, which were subjected in parallel form to 80 successive exposures of UV light with inserted periods of growth are reported. (Author)

Identificação de cepas de Escherichia coli enteropatogênicas em amostras de fezes, por reação de imunofluorescência direta Identification of strains of Escherichia coli in stool samples by direct fluorescent antibody tests

Directory of Open Access Journals (Sweden)

Ieda Maria Longo

1980-06-01

Full Text Available Foi realizado diagnóstico etiológico de casos de diarréia aguda em 121 pacientes internados na Clínica Pediátrica do Hospital da Santa Casa de São Paulo, Brasil. Foram utilizados os métodos bacteriológico clássico e de reação de imunofluorescência direta para a identificação de cepas de Escherichia coli enteropatogênicas: para estudo da sensibilidade das cepas de Escherichia coli isoladas, a diferentes antibióticos, foi usado o método de Concentração Inibitória Minima (CIM. Dos 56 casos positivos, 89,3% correspondiam a diferentes sorotipos enteropatogênicos de Escherichia coli, quando utilizada a técnica de imunofluorescência direta. O método bacteriológico clássico revelou ainda, nos 121 casos examinados, 4 cepas de Salmonella e 2 de Shigella. No estudo da CIM verificou-se maior sensibilidade das cepas de Escherichia coli enteropatogênicas estudadas à Gentamicina e Amikacina, do que aos outros antibióticos.A study of 121 patients with acute diarrhea was made at the Pediatric Clinic of the Santa Casa de S. Paulo (the S. Paulo Charity Hospital. Etiological diagnosis of 121 cases was carried out through the classical bacteriological method and direct fluorescent antibody tests for the identification of E. coli. The antibiotic sensitivity of these bacteria to different antimicrobials was determined by the Minimum Inhibitory Concentration (MIC method. Fifty-six positive cases were found; 89.3% of which corresponded to different serotypes of enter o pathogenic E. coli (89.3%, when the direct fluorescent antibody test was used. The classic bacteriological method bared four Salmonella strains and two Shigella. The MIC showed the E. coli to be more sensitive to Gentamicin and Amikacin than to other antibiotics.

Removal of Escherichia coli from biological effluents using natural ...

African Journals Online (AJOL)

Ability for disinfecting sterile biological effluents inoculated with Escherichia coli ATCC 25922 at concentrations of 105 CFU/m., using a natural mineral aggregate (NMA) and artificial mineral aggregates (AMAfs) consisting of individual oxides as Fe2O3, Cu2O y Ag2O and combined oxides as Fe2O3-Cu2O, Fe2O3-Ag2O, ...

Probiotic Mixture Golden Bifido Prevents Neonatal Escherichia coli K1 Translocation via Enhancing Intestinal Defense

OpenAIRE

Qing Zeng; Xiaolong He; Santhosh Puthiyakunnon; Hansen Xiao; Zelong Gong; Swapna Boddu; Lecheng Chen; Huiwen Tian; Huiwen Tian; Sheng-He Huang; Sheng-He Huang; Hong Cao

2017-01-01

Escherichia coli (E. coli) K1 sepsis and meningitis is a severe infection characterized by high mortality in neonates. Successful colonization and translocation across the intestinal mucosa have been regarded as the critical steps for E. coli K1 sepsis and meningitis. We recently reported that the probiotic mixture, Golden Bifido (containing live Lactobacillus bulgaricus, Bifidobacterium, and Streptococcus thermophilus, LBS) has a preventive role against neonatal E. coli K1 bacteremia and men...

Pathogenic Potential to Humans of Bovine Escherichia coli O26, Scotland

Science.gov (United States)

Rosser, Tracy; Allison, Lesley J.; Courcier, Emily; Evans, Judith; McKendrick, Iain J.; Pearce, Michael C.; Handel, Ian; Caprioli, Alfredo; Karch, Helge; Hanson, Mary F.; Pollock, Kevin G.J.; Locking, Mary E.; Woolhouse, Mark E.J.; Matthews, Louise; Low, J. Chris; Gally, David L.

2012-01-01

Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx2 in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx2 phage acquisition. PMID:22377426

A stochastic killing system for biological containment of Escherichia coli

DEFF Research Database (Denmark)

Klemm, P.; Jensen, Lars Bogø; Molin, Søren

1995-01-01

Bacteria with a stochastic conditional lethal containment system have been constructed. The invertible switch promoter located upstream of the fimA gene from Escherichia coli was inserted as expression cassette in front of the Lethal gef gene deleted of its own natural promoter. The resulting...... fusion was placed on a plasmid and transformed to E. coli. The phenotype connected with the presence of such a plasmid was to reduce the population growth rate with increasing significance as the cell growth rate was reduced. In very fast growing cells, there was no measurable effect on growth rate. When...

A Structural Study of Escherichia coli Cells Using an In Situ Liquid Chamber TEM Technology

Directory of Open Access Journals (Sweden)

Yibing Wang

2015-01-01

Full Text Available Studying cell microstructures and their behaviors under living conditions has been a challenging subject in microbiology. In this work, in situ liquid chamber TEM was used to study structures of Escherichia coli cells in aqueous solutions at a nanometer-scale resolution. Most of the cells remained intact under electron beam irradiation, and nanoscale structures were observed during the TEM imaging. The analysis revealed structures of pili surrounding the E. coli cells; the movements of the pili in the liquid were also observed during the in situ tests. This technology also allowed the observation of features of the nucleoid in the E. coli cells. Overall, in situ TEM can be applied as a valuable tool to study real-time microscopic structures and processes in microbial cells residing in native aqueous solutions.

Integrons in Escherichia coli from food-producing animals in The Netherlands

NARCIS (Netherlands)

Box, A.T.; Mevius, D.J.; Schellen, P.; Verhoef, J.; Fluit, A.C.

2005-01-01

The presence and character of class 1 integrons in multidrug-resistant Escherichia coli from slaughter animals and meat was determined by integrase-specific PCR and conserved segment PCR-restriction fragment length polymorphism (RFLP). At least five different class 1 integron types were found and

Thermal inactivation of Escherichia coli 0157:H7 (ECOH) and non-0157 Shiga toxin-producing E.coli (STEC)in mechanically tenderized veal

Science.gov (United States)

We quantified thermal destruction of Shiga toxin-producing Escherichia coli O157:H7 (ECOH) and Shiga toxin-producing non-O157 E. coli (STEC) cells within mechanically tenderized veal cutlets following cooking on an electric skillet. For each of five trials, flattened veal cutlets (ca. 71.6 g; ca. 1/...

Effects of recombinant human collagen VI from Escherichia coli on ...

African Journals Online (AJOL)

Jane

2011-07-20

Jul 20, 2011 ... In this study, we reported the cloning and over expression of a gene coding for human collagen peptide. (CP6) in Escherichia coli and investigated the protective effects of CP6 on UVA-irradiated human skin fibroblasts cells. The collagen peptide (CP6) was highly soluble and the expression level was.

Design of cAMP-CRP-activated promoters in Escherichia coli

DEFF Research Database (Denmark)

Valentin-Hansen, P; Holst, B; Søgaard-Andersen, L

1991-01-01

We have studied the deoP2 promoter of Escherichia coli to define features that are required for optimal activation by the complex of adenosine 3',5' monophosphate (cAMP) and the cAMP receptor protein (CRP). Systematic mutagenesis of deoP2 shows that the distance between the CRP site and the -10...

Quantification of plasmid DNA reference materials for Shiga toxin-producing Escherichia coli based on UV, HR-ICP-MS and digital PCR.

Science.gov (United States)

Liang, Wen; Xu, Li; Sui, Zhiwei; Li, Yan; Li, Lanying; Wen, Yanli; Li, Chunhua; Ren, Shuzhen; Liu, Gang

2016-01-01

The accuracy and metrology traceability of DNA quantification is becoming a critical theme in many fields, including diagnosis, forensic analysis, microorganism detection etc. Thus the research of DNA reference materials (RMs) and consistency of DNA quantification methods has attracted considerable research interest. In this work, we developed 3 plasmid candidate RMs, containing 3 target genes of Escherichia coli O157:H7 (E. coli O157:H7) and other Shiga toxin-producing Escherichia coli (STEC): stx1, stx2, and fliC (h7) respectively. Comprehensive investigation of the plasmid RMs was performed for their sequence, purity, homogeneity and stability, and then the concentration was quantified by three different methods: ultraviolet spectrophotometer (UV), high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) and digital PCR. As a routinely applied method for DNA analysis, UV was utilized for the quantification (OD260) and purity analysis for the plasmids. HR-ICP-MS quantified the plasmid DNA through analysing the phosphorus in DNA molecules. Digital PCR distributed the DNA samples onto a microarray chip containing thousands of reaction chambers, and quantified the DNA copy numbers by analysing the number of positive signals without any calibration curves needed. Based on the high purification of the DNA reference materials and the optimization of dPCR analysis, we successfully achieved good consistency between UV, HR-ICP-MS and dPCR, with relative deviations lower than 10 %. We then performed the co-quantification of 3 DNA RMs with three different methods together, and the uncertainties of their concentration were evaluated. Finally, the certified values and expanded uncertainties for 3 DNA RMs (pFliC, pStx1 and pStx2) were (1.60 ± 0.10) × 10(10) copies/μL, (1.53 ± 0.10) × 10(10) copies/μL and (1.70 ± 0.11) × 10(10) copies/μL respectively.Graphical abstractWe developed 3 plasmid candidate RMs, containing 3 target genes of

Study of Sensibility and Antimicrobial Resistance in Escherichia coli Isolated from Urinary Tract Infection in Tabriz City

Directory of Open Access Journals (Sweden)

Hamed Molaabaszadeh

2013-09-01

Full Text Available  Background & Objective: Urinary infection is one of the most prevalent infectious diseases, and Escherichia coli is the most important cause of urinary infections. This study was done with the aim of surveying the amount of susceptibility and resistance among the strains of Escherichia coli isolated from those who referred to the private laboratories in the Iranian city of Tabriz.   Materials & Methods: This survey was done periodically during the first 6 months of the year 2010. Samples were obtained in a sterile manner and were subjected to all necessary pathological tests. Evaluation of antibiotic susceptibility was conducted with disk diffusion standard method, and the results were analyzed.   Results: Totally, 5701 Escherichia coli strains were identified. The highest sensitivity to Imipenem was 90.95%, Nitrofurantoin 85.97%, and Cefotaxime 71.02% and the highest resistance to Ampicillin was 83.95%, Tetracycline 80.97%, and Co-trimoxazole 63.92%.   Conclusion: Our results suggest that the cause of the high resistance of Escherichia coli strains to Ampicillin and Tetracycline could be the consumption of these antibiotics. Therefore, abstaining from overuse of unnecessary antibiotics and production of new-generation and cost-effective antibiotics are recommend. 

Effect of radiation doses rate on SOS response induction in irradiated Escherichia coli Cells

International Nuclear Information System (INIS)

Cuetara Lugo, Elizabeth B.; Fuentes Lorenzo, Jorge L.; Almeida Varela, Eliseo; Prieto Miranda, Enrique F.; Sanchez Lamar, Angel; Llagostera Casal, Montserrat

2005-01-01

The present work is aimed to study the effect of radiation dose rate on the induction of SOS response in Escherichia coli cells. We measured the induction of sul A reporter gene in PQ-37 (SOS Chromotest) cells. Lead devises were built with different diameter and these were used for diminishing the dose rate of PX- -30M irradiator. Our results show that radiation doses rate significantly modifies the induction of SOS response. Induction factor increases proportionally to doses rate in Escherichia coli cells defective to nucleotide excision repair (uvrA), but not in wild type cells. We conclude that the dose rate affects the level of induction of SOS response

Proliferation of Escherichia coli O157:H7 in soil and hydroponic microgreen production systems

Science.gov (United States)

Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157: H7 using soil substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants and in growth medium were examined....

DNA fingerprinting approaches to trace Escherichia coli sharing between dogs and owners.

Science.gov (United States)

Naziri, Z; Derakhshandeh, A; Firouzi, R; Motamedifar, M; Shojaee Tabrizi, A

2016-02-01

To determine the prevalence of cross-species sharing of Escherichia coli between healthy dogs and humans living in the same household. Two faecal E. coli isolates from 25 healthy dog-owner pairs and 16 healthy control humans were tested using three fingerprinting methods. The prevalence of within-household sharing of E. coli was 4, 8 and 8% using pulsed-field gel electrophoresis, randomly amplified polymorphic DNA and enterobacterial repetitive intergenic consensus-PCR analyses respectively. Within-household bacterial sharing was more prevalent than across-household sharing (P fingerprinting techniques will help to find ways for reducing the economic impact of E. coli infections. This study support claims that public health concerns regarding the cross-species sharing of E. coli are warranted but this risk is minimal. © 2015 The Society for Applied Microbiology.

Construction of Methanol-Sensing Escherichia coli by the Introduction of a Paracoccus denitrificans MxaY-Based Chimeric Two-Component System.

Science.gov (United States)

Ganesh, Irisappan; Vidhya, Selvamani; Eom, Gyeong Tae; Hong, Soon Ho

2017-06-28

Escherichia coli was engineered to sense methanol by employing a chimeric two-component system (TCS) strategy. A chimeric MxaY/EnvZ (MxaYZ) TCS was constructed by fusing the Paracoccus denitrificans MxaY with the E. coli EnvZ. Real-time quantitative PCR analysis and GFP-based fluorescence analysis showed maximum transcription of ompC and the fluorescence at 0.01% of methanol, respectively. These results suggested that E. coli was successfully engineered to sense methanol by the introduction of chimeric MxaYZ. By using this strategy, various chimeric TCS-based bacterial biosensors can be constructed and used for the development of biochemical-producing recombinant microorganisms.

Phosphoribosylpyrophosphate synthetase of Escherichia coli. Properties of the purified enzyme and primary structure of the prs gene

DEFF Research Database (Denmark)

Hove-Jensen, Bjarne; Harlow, Kenneth W.; King, Cheryl J.

1986-01-01

of ADP. The nucleotide sequence of the E. coli prs gene has been determined and the coding segment established. The deduced amino acid sequence of P-Rib-PP synthetase contained 314 amino acid residues and the molecular weight was calculated as 34,060. The initiation site of transcription was determined......Phosphoribosylpyrophosphate (P-Rib-PP) synthetase of Escherichia coli has been purified to near homogeneity from a strain harboring the prs gene, encoding P-Rib-PP synthetase, on a multicopy plasmid. Analysis of the enzyme showed that it required inorganic phosphate for activity and for stability...

Effect of a static magnetic field on Escherichia coli adhesion and orientation

Czech Academy of Sciences Publication Activity Database

Mhamdi, L.; Mhamdi, N.; Mhamdi, Nc.; Lejeune, M.; Jaffrezic, N.; Burais, N.; Scorretti, R.; Pokorný, Jiří; Ponsonnet, L.

2016-01-01

Roč. 62, č. 11 (2016), s. 944-952 ISSN 0008-4166 Institutional support: RVO:67985882 Keywords : Fluorescence microscopy * Static magnetic field * Escherichia coli Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.462, year: 2016

Two mechanisms coordinate replication termination by the Escherichia coli Tus–Ter complex

KAUST Repository

Pandey, Manjula; Elshenawy, Mohamed; Jergic, Slobodan; Takahashi, Masateru; Dixon, Nicholas E.; Hamdan, Samir; Patel, Smita S.

2015-01-01

The Escherichia coli replication terminator protein (Tus) binds to Ter sequences to block replication forks approaching from one direction. Here, we used single molecule and transient state kinetics to study responses of the heterologous phage T7

ROS mediated selection for increased NADPH availability in Escherichia coli.

Science.gov (United States)

Reynolds, Thomas S; Courtney, Colleen M; Erickson, Keesha E; Wolfe, Lisa M; Chatterjee, Anushree; Nagpal, Prashant; Gill, Ryan T

2017-11-01

The economical production of chemicals and fuels by microbial processes remains an intense area of interest in biotechnology. A key limitation in such efforts concerns the availability of key co-factors, in this case NADPH, required for target pathways. Many of the strategies pursued for increasing NADPH availability in Escherichia coli involve manipulations to the central metabolism, which can create redox imbalances and overall growth defects. In this study we used a reactive oxygen species based selection to search for novel methods of increasing NADPH availability. We report a loss of function mutation in the gene hdfR appears to increase NADPH availability in E. coli. Additionally, we show this excess NADPH can be used to improve the production of 3HP in E. coli. © 2017 Wiley Periodicals, Inc.

Elimination of Escherichia coli and Salmonella in Clam by Using Zeolite in a Station of Depuration.

Science.gov (United States)

Gdoura, Morsi; Sellami, Hanen; Khannous, Lamia; Ketata, Najib; Neila, Idriss Ben; Traore, Al Ibrahim; Chekir, Zouhair; Gdoura, Radhouane

2017-09-01

  The application of natural zeolite for water and wastewater treatment has been carried out and is still a promising technique in environmental cleaning processes. Natural zeolite can be used to improve the purification process of clams (Ruditapes decussatus). Thus, our study aimed at improving the clam purification system in order to reduce Escherichia coli and eliminate Salmonella in samples artificially contaminated with this bacterium using a natural zeolite to replace the biological filter. The results showed that zeolite used in a depuration system improved the clam purification process. Moreover, natural zeolite exhibited high performance in the adsorption of bacteria and allowed to reduce the Escherichia coli abundance in 24 h, thus ensuring purified clams conformity with the ISO 16649-3 standard. These results indicate the beneficial effects of using zeolite in the adsorption of bacteria and the reduction in the abundance of Escherichia coli and set the Salmonella from marine organisms.

Determination of the prevalence of subclinical endometritis and evaluation of molecular characterization of Escherichia coli (E-coli separated of them in mares repeat breeder in Yazd province

Directory of Open Access Journals (Sweden)

Taktaz Hafshejani Taghi

2016-11-01

Full Text Available Escherichia coli are known as the most common cause of reproductive tract infection in mare. Due to the progressive process of antibiotics use and increasing prevalence of antibiotic resistance, the aim of this study is evaluate the prevalence of subclinical endometritis and antibiotic resistance genes in Escherichia coli isolated. In this study, 60 mares were used with infertility background. Diagnosis of endometritis was performed using history and ultrasonography. Cytology, culture, Antibiogram were done of samples and PCR test was used to examine the gene virulence and antibiotic resistance. E-coli bacteria was isolated 48/33 % from sample culture. In PCR test 66/21 % of bacteria had virulence gene. It was determined, the lowest resistance to chloramphenicol about 38/15% and greatest resistance into ampicillin, tetracycline and streptomycin with 23/69 percent, respectively. 93% samples cytology had neutrophil more than two and the agent of 50% showed E. coli. The cause of half of subclinical endometritis in infertile maresis E-coli bacteriaEscherichia coli are known as the most common cause of reproductive tract infection in mare. Due to the progressive process of antibiotics use and increasing prevalence of antibiotic resistance, the aim of this study is evaluate the prevalence of subclinical endometritis and antibiotic resistance genes in Escherichia coli isolated. In this study, 60 mares were used with infertility background. Diagnosis of endometritis was performed using history and ultrasonography. Cytology, culture, Antibiogram were done of samples and PCR test was used to examine the gene virulence and antibiotic resistance. E-coli bacteria was isolated 48/33 % from sample culture. In PCR test 66/21 % of bacteria had virulence gene. It was determined, the lowest resistance to chloramphenicol about 38/15% and greatest resistance into ampicillin, tetracycline and streptomycin with 23/69 percent, respectively. 93% samples cytology had

Triosephosphate isomerase is a common crystallization contaminant of soluble His-tagged proteins produced in Escherichia coli

International Nuclear Information System (INIS)

Kozlov, Guennadi; Vinaik, Roohi; Gehring, Kalle

2013-01-01

Crystals of E. coli triosephosphate isomerase were obtained as a contaminant and its structure was determined to 1.85 Å resolution. Attempts to crystallize several mammalian proteins overexpressed in Escherichia coli revealed a common contaminant, triosephosphate isomerase, a protein involved in glucose metabolism. Even with triosephosphate isomerase present in very small amounts, similarly shaped crystals appeared in the crystallization drops in a number of polyethylene glycol-containing conditions. All of the target proteins were His-tagged and their purification involved immobilized metal-affinity chromatography (IMAC), a step that was likely to lead to triosephosphate isomerase contamination. Analysis of the triosephosphate isomerase crystals led to the structure of E. coli triosephosphate isomerase at 1.85 Å resolution, which is a significant improvement over the previous structure

Crystallization and preliminary X-ray analysis of the inducible lysine decarboxylase from Escherichia coli

International Nuclear Information System (INIS)

Alexopoulos, Eftichia; Kanjee, Usheer; Snider, Jamie; Houry, Walid A.; Pai, Emil F.

2008-01-01

The structure of the decameric inducible lysine decarboxylase from E. coli was determined by SIRAS using a hexatantalum dodecabromide (Ta 6 Br 12 2+ ) derivative. Model building and refinement are under way. The decameric inducible lysine decarboxylase (LdcI) from Escherichia coli has been crystallized in space groups C2 and C222 1 ; the Ta 6 Br 12 2+ cluster was used to derivatize the C2 crystals. The method of single isomorphous replacement with anomalous scattering (SIRAS) as implemented in SHELXD was used to solve the Ta 6 Br 12 2+ -derivatized structure to 5 Å resolution. Many of the Ta 6 Br 12 2+ -binding sites had twofold and fivefold noncrystallographic symmetry. Taking advantage of this feature, phase modification was performed in DM. The electron-density map of LdcI displays many features in agreement with the low-resolution negative-stain electron-density map [Snider et al. (2006 ▶), J. Biol. Chem.281, 1532–1546

[The antibacterial activity of oregano essential oil (Origanum heracleoticum L.) against clinical strains of Escherichia coli and Pseudomonas aeruginosa].

Science.gov (United States)

Sienkiewicz, Monika; Wasiela, Małgorzata; Głowacka, Anna

2012-01-01

The aim of this study was to investigate the antibacterial properties of oregano (Origanum heracleoticum L.) essential oil against clinical strains of Escherichia coli and Pseudomonas aeruginosa. The antibacterial activity of oregano essential oil was investigate against 2 tested and 20 clinical bacterial strains of Escherichia coli and 20 clinical strains o Pseudomonas aeruginosa come from patients with different clinical conditions. The agar dilution method was used for microbial growth inhibition at various concentrations ofoil. Susceptibility testing to antibiotics was carried out using disc-diffusion method. The results of experiments showed that the tested oil was active against all of the clinical strains from both genus of bacteria, but strains of Escherichia coli were more sensitive to tested oil. Essential oil from Origanum heracleoticum L. inhibited the growth of Escherichia coli and Pseudomonas aeruginosa clinical strains with different patters of resistance. The obtained outcomes will enable further investigations using oregano essential oil obtained from Origanum heracleoticum L. as alternative antibacterial remedies enhancing healing process in bacterial infections and as an effective means for the prevention of antibiotic-resistant strain development.

[Application of DNA-based electrochemical biosensor in rapid detection of Escherichia coli exist in licorice decoction].

Science.gov (United States)

Zhao, Yu-Wen; Wang, Hai-Xia; Bie, Song-Tao; Shao, Qian; Wang, Chun-Hua; Wang, Dong-Heng; Li, Zheng

2018-03-01

A new method for detection of Escherichia coli exist in licorice decoction was developed by using DNA-based electrochemical biosensor. The thiolated capture probe was immobilized on a gold electrode at first. Then the aptamer for Escherichia coli was combined with the capture probe by hybridization. Due to the stronger interaction between the aptamer and the E. coli, the aptamer can dissociate from the capture probe in the presence of E. coli in licorice decoction. The biotinylated detection probe was hybridized with the single-strand capture probe. As a result, the electrochemical response to Escherichia coli can be measured by using differential pulse voltammetric in the presence of α-naphthyl phosphate. The plot of peak current vs. the logarithm of concentration in the range from 2.7×10² to 2.7×10⁸ CFU·mL⁻¹ displayed a linear relationship with a detection limit of 50 CFU·mL⁻¹. The relative standard deviation of 3 successive scans was 2.5%，2.1%，4.6% for 2×10²，2×10⁴，2×106：⁶ CFU·mL⁻¹ E. coli, respectively. The proposed procedure showed better specificity to E. coli in comparison to Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. In the detection of the real extractum glycyrrhizae, the results between the proposed strategy and the GB assay showed high degree of agreement, demonstrating the designed biosensor could be utilized as a powerful tool for microbial examination for traditional Chinese medicine. Copyright© by the Chinese Pharmaceutical Association.

Applying torque to the Escherichia coli flagellar motor using magnetic tweezers

NARCIS (Netherlands)

van Oene, M.M.; Dickinson, L.E.; Cross, B.; Pedaci, F.; Lipfert, J.; Dekker, N.H.

2017-01-01

The bacterial flagellar motor of Escherichia coli is a nanoscale rotary engine essential for bacterial propulsion. Studies on the power output of single motors rely on the measurement of motor torque and rotation under external load. Here, we investigate the use of magnetic tweezers, which in

Specific structural probing of plasmid-coded ribosomal RNAs from Escherichia coli

DEFF Research Database (Denmark)

Aagaard, C; Rosendahl, G; Dam, M

1991-01-01

The preferred method for construction and in vivo expression of mutagenised Escherichia coli ribosomal RNAs (rRNAs) is via high copy number plasmids. Transcription of wild-type rRNA from the seven chromosomal rrn operons in strains harbouring plasmid-coded mutant rRNAs leads to a heterogeneous...

The emergence and fate of horizontally acquired genes in Escherichia coli

NARCIS (Netherlands)

Passel, van M.W.J.; Marri, P.R.; Ochman, H.

2008-01-01

Bacterial species, and even strains within species, can vary greatly in their gene contents and metabolic capabilities. We examine the evolution of this diversity by assessing the distribution and ancestry of each gene in 13 sequenced isolates of Escherichia coli and Shigella. We focus on the

The population structure of Escherichia coli isolated from subtropical and temperate soils

Science.gov (United States)

Byappanahalli, Muruleedhara N.; Yan, Tao; Hamilton, Matthew J.; Ishii, Satoshi; Fujioka, Roger S.; Whitman, Richard L.; Sadowsky, Michael J.

2012-01-01

While genotypically-distinct naturalized Escherichia coli strains have been shown to occur in riparian soils of Lake Michigan and Lake Superior watersheds, comparative analyses of E. coli populations in diverse soils across a range of geographic and climatic conditions have not been investigated. The main objectives of this study were to: (a) examine the population structure and genetic relatedness of E. coli isolates collected from different soil types on a tropical island (Hawaii), and (b) determine if E. coli populations from Hawaii and temperate soils (Indiana, Minnesota) shared similar genotypes that may be reflective of biome-related soil conditions. DNA fingerprint and multivariate statistical analyses were used to examine the population structure and genotypic characteristics of the E. coli isolates. About 33% (98 of 293) of the E. coli from different soil types and locations on the island of Oahu, Hawaii, had unique DNA fingerprints, indicating that these bacteria were relatively diverse; the Shannon diversity index for the population was 4.03. Nearly 60% (171 of 293) of the E. coli isolates from Hawaii clustered into two major groups and the rest, with two or more isolates, fell into one of 22 smaller groups, or individual lineages. Multivariate analysis of variance of 89, 21, and 106 unique E. coli DNA fingerprints for Hawaii, Indiana, and Minnesota soils, respectively, showed that isolates formed tight cohesive groups, clustering mainly by location. However, there were several instances of clonal isolates being shared between geographically different locations. Thus, while nearly identical E. coli strains were shared between disparate climatologically- and geographically-distinct locations, a vast majority of the soil E. coli strains were genotypically diverse and were likely derived from separate lineages. This supports the hypothesis that these bacteria are not unique and multiple genotypes can readily adapt to become part of the soil autochthonous

Binding of Divalent Magnesium by Escherichia coli Phosphoribosyl Diphosphate Synthetase

DEFF Research Database (Denmark)

Willemoës, Martin; Hove-Jensen, Bjarne

1997-01-01

The mechanism of binding of the substrates MgATP and ribose 5-phosphate as well as Mg2+ to the enzyme 5-phospho-d-ribosyl a-1-diphosphate synthetase from Escherichia coli has been analyzed. By use of the competive inhibitors of ATP and ribose 5-phosphate binding, a,ß-methylene ATP and (+)-1-a,2-a...

QSAR study of benzimidazole derivatives inhibition on escherichia coli methionine Aminopeptidase

Directory of Open Access Journals (Sweden)

Zahra Garkani-Nejad

2010-06-01

Full Text Available The paper describes a quantitative structure-activity relationship (QSAR study of IC50 values of benzimidazole derivatives on escherichia coli methionine aminopeptidase. The activity of the 32 inhibitors has been estimated by means of multiple linear regression (MLR and artificial neural network (ANN techniques. The results obtained using the MLR method indicate that the activity of derivatives of benzimidazoles on CoII-loaded escherichia coli methionine aminopeptidase depend on different parameters containing topological descriptors, Burden eigen values, 3D MoRSE descriptors and 2D autocorrelation descriptors. The best artificial neural network model is a fully-connected, feed forward back propagation network with a 5-4-1 architecture. Standard error for the training set using this network was 0.193 with correlation coefficient 0.996 and for the prediction set standard error was 1.41 with correlation coefficient 0.802. Comparison of the quality of the ANN with different MLR models showed that ANN has a better predictive power.