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Sample records for clinical escherichia coli

  1. 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,...

  2. Escherichia Coli

    Science.gov (United States)

    Goodsell, David S.

    2009-01-01

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

  3. Antimicrobial sensitivity pattern among clinical isolates of Escherichia coli in tertiary care centre of Northern India

    OpenAIRE

    Ranjana Malhotra; Rama Sikka; Uma Chaudhary

    2016-01-01

    Background: Rampant rise in resistance to various antimicrobials among clinical isolates of Escherichia coli is an issue of serious concern, especially in developing countries. It not only causes failure in treatment but also pose a health burden over the society at large. Methods: Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method on Muller Hinton agar as per Clinical and Laboratory Standard Institute recommendations over 100 isolates of E. coli. Isola...

  4. Prevention of clinical coliform mastitis in dairy cows by a mutant Escherichia coli vaccine.

    OpenAIRE

    González, R N; Cullor, J S; Jasper, D. E.; Farver, T B; Bushnell, R B; Oliver, M N

    1989-01-01

    A prospective cohort study was undertaken in two commercial California dairies. The treatment group, 246 cows, received three doses of a whole cell bacterin of J5 Escherichia coli (mutant of E. coli O111:B4) plus Freund's incomplete adjuvant vaccine (two in the dry period and one after calving) while 240 unvaccinated cows served as controls. Thirty-five cases of clinical coliform mastitis were diagnosed, six in vaccinated cows and 29 in unvaccinated cows. Bacteria isolated from the clinical c...

  5. Escherichia coli Peritonitis in Peritoneal Dialysis: The Prevalence, Antibiotic Resistance and Clinical Outcomes in a South China Dialysis Center

    OpenAIRE

    FENG, XIAORAN; Yang, Xiao; Yi, Chunyan; Guo, Qunying; Mao, Haiping; Jiang, Zongpei; Li, Zhibin; Chen, Dongmei; Cui, Yingpeng; Yu, Xueqing

    2014-01-01

    ♦ Introduction: Escherichia coli (E. coli) peritonitis is a frequent, serious complication of peritoneal dialysis (PD). The extended-spectrum β-lactamase (ESBL)-producing E. coli peritonitis is associated with poorer prognosis and its incidence has been on continuous increase during the last decades. However, the clinical course and outcomes of E. coli peritonitis remain largely unclear.

  6. Epidemiological and clinical complexity of amoxicillin-clavulanate-resistant Escherichia coli.

    Science.gov (United States)

    Rodríguez-Baño, Jesús; Oteo, Jesús; Ortega, Adriana; Villar, Macarena; Conejo, M Carmen; Bou, Germán; Aranzamendi-Zaldumbide, Maitane; Cercenado, Emilia; Gurguí, Mercè; Martínez-Martínez, Luis; Merino, María; Rivera, Alba; Oliver, Antonio; Weber, Irene; Pascual, Alvaro; Bartolomé, Rosa M; Gónzalez-López, Juan José; Campos, José

    2013-07-01

    Two hundred twelve patients with colonization/infection due to amoxicillin-clavulanate (AMC)-resistant Escherichia coli were studied. OXA-1- and inhibitor-resistant TEM (IRT)-producing strains were associated with urinary tract infections, while OXA-1 producers and chromosomal AmpC hyperproducers were associated with bacteremic infections. AMC resistance in E. coli is a complex phenomenon with heterogeneous clinical implications. PMID:23637303

  7. Escherichia coli harboring Shiga toxin 2 gene variants : frequency and association with clinical symptoms

    NARCIS (Netherlands)

    Friedrich, Alexander W; Bielaszewska, Martina; Zhang, Wen-Lan; Pulz, Matthias; Kuczius, Thorsten; Ammon, Andrea; Karch, Helge

    2002-01-01

    Shiga toxin (Stx)-producing Escherichia coli (STEC) from patients with hemolytic-uremic syndrome (HUS), patients with diarrhea without HUS, or asymptomatic subjects were genotyped to assess associations between stx2 variants and clinical manifestations of infection. Neither stx2d nor stx2e was found

  8. Relationship between Genomic Types of Escherichia coli and Clinical Diseases

    Institute of Scientific and Technical Information of China (English)

    Meiying YI; Ruen LIU; Hanju HUANG

    2008-01-01

    In this study, by analysis of genome structures of E. coli, the relationships Between the genomic types of E. coli and the associated diseases were investigated. Samples of sputum, urine and other excretions from patients with different infective diseases were collected. And 62 E. coli strains were isolated from these samples. Intact bacterial genomic DNA was cleaved with I-CeuI, separated by pulsed field gel electrophoresis and then typed on the basis of cleavage map. The results showed that 7 I-CeuI sites were found in all the genome structures of the 62 E. coli, indicating that there were 7 rrn operons in the genomes. The size of genome ranged from 4500 kb to 5000 kb. According to thegenome structures, 62 E. coli strains were divided into 30 genome types. It was concluded that genome structures of E. coli isolated from the patients with different infective diseases varied to some extent, suggesting that some genome types of E. coli were closely related to some infective diseases.

  9. Molecular Basis of AmpC Hyperproduction in Clinical Isolates of Escherichia coli

    OpenAIRE

    Nelson, E C; Elisha, B. Gay

    1999-01-01

    DNA sequencing data showed that five clinical isolates of Escherichia coli with reduced susceptibility to ceftazidime, ceftriaxone, and cefotaxime contain an ampC gene that is preceded by a strong promoter. Transcription from the strong promoter was 8- to 18-fold higher than that from the promoter from a susceptible isolate. RNA studies showed that mRNA stability does not play a role in the control of AmpC synthesis.

  10. Taxonomy Icon Data: Escherichia coli [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Escherichia coli Escherichia coli Escherichia_coli_L.png Escherichia_coli_NL.png Escherichia_coli..._S.png Escherichia_coli_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Escherichia+coli...&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Escherichia+coli&t=NL http://biosciencedbc.jp/taxono...my_icon/icon.cgi?i=Escherichia+coli&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Escherichia+coli&t=NS ...

  11. Antibody specific for Escherichia coli J5 cross-reacts to various degrees with an Escherichia coli clinical isolate grown for different lengths of time.

    OpenAIRE

    McCallus, D E; Norcross, N. L.

    1987-01-01

    Rabbit antiserum raised against the rough mutant of Escherichia coli O111:B4, designated J5, was examined for cross-reactivity to an E. coli clinical isolate (A2385). In whole-cell enzyme-linked immunosorbent assays, J5 antiserum reacted to a greater extent with A2385 grown for 5 h than with the same bacteria grown for 19 h, while the homologous antiserum reacted similarly with bacteria grown for different lengths of time. J5 antiserum reacted to the greatest extent with lipopolysaccharide (L...

  12. Prevalence and molecular characterization of clinical isolates of Escherichia coli expressing an AmpC phenotype

    DEFF Research Database (Denmark)

    Jørgensen, Rikke Lind; Nielsen, Jesper Boye; Friis-Møller, Alice; Fjeldsøe-Nielsen, Hans; Schønning, Kristian

    2010-01-01

    OBJECTIVES: To establish the prevalence of the AmpC beta-lactamase phenotype in clinical isolates of Escherichia coli and characterize the genetic resistance mechanisms causing the observed phenotype. METHODS: Clinical E. coli (n = 74) with reduced susceptibility to third-generation cephalosporins...... and resistance to cefoxitin were collected from the Department of Clinical Microbiology at Hvidovre Hospital, Denmark, in 2006. The AmpC disc test was used to confirm expression of AmpC, and test-positive strains were selected for further antimicrobial susceptibility testing and molecular...... characterization. Hyperproduction of AmpC beta-lactamase was confirmed by isoelectric focusing (IEF). The presence of a plasmid-mediated ampC gene (pAmpC) was detected by multiplex PCR. The promoter and the entire reading frame of the chromosomal ampC gene were sequenced to identify promoter mutations associated...

  13. Recurrent Escherichia coli bacteremia.

    OpenAIRE

    Maslow, J.N.; Mulligan, M E; Arbeit, R D

    1994-01-01

    Escherichia coli is the most common gram-negative organism associated with bacteremia. While recurrent E. coli urinary tract infections are well-described, recurrent E. coli bacteremia appears to be uncommon, with no episodes noted in multiple series of patients with gram-negative bacteremias. We report on 5 patients with recurrent bloodstream infections identified from a series of 163 patients with E. coli bacteremia. For each patient, the isolates from each episode were analyzed by pulsed-f...

  14. Evaluation of extended spectrum beta lactamase enzymes prevalence in clinical isolates of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ronak Bakhtiari

    2011-10-01

    Full Text Available Resistance to b-lactam antibiotics by gramnegative bacteria, especially Escherichia coli (E. coli, is a major public health issue worldwide. The predominant resistance mechanism in gram negative bacteria particularly E. coli is via the production of extended spectrum beta lactamase (ESBLs enzymes. In recent years, the prevalence of b-lactamase producing organisms is increased and identification of these isolates by using disk diffusion method and no-one else is not satisfactory. So, this investigation focused on evaluating the prevalence of ESBL enzymes by disk diffusion method and confirmatory test (Combined Disk. Five hundred clinical samples were collected and 200 E. coli isolates were detected by standard biochemical tests. To performing initial screening of ESBLs was used from Disk diffusion method on E. coli isolates. A confirmation test (Combined Disk method was performed on isolates of resistant to cephalosporin's indicators. Up to 70% isolates exhibited the Multi Drug Resistance phenotype. In Disk diffusion method, 128(64% E. coli isolates which resistant to ceftazidime and cefotaxime while in Combined Disk, among 128 screened isolates, 115 (89.8% isolates were detected as ESBLs producers. This survey indicate beta lactamase enzymes are playing a significant role in antibiotic resistance and correct detection of them in phenotypic test by using disk diffusion and combined Disk is essential for accurate recognition of ESBLs.

  15. AmpC β-Lactamase in an Escherichia coli Clinical Isolate Confers Resistance to Expanded-Spectrum Cephalosporins

    OpenAIRE

    Mammeri, Hedi; Nazic, Hasan; Naas, Thierry; Poirel, Laurent; Léotard, Sophie; Nordmann, Patrice

    2004-01-01

    Cloning, sequencing, and biochemical analysis identified a novel AmpC-type β-lactamase conferring resistance to extended-spectrum cephalosporins in an Escherichia coli clinical isolate. This enzyme, exhibiting 14 amino acid substitutions compared to a reference AmpC cephalosporinase of E. coli, hydrolyzed ceftazidime and cefepime significantly.

  16. Antimicrobial Susceptibility and Molecular Mechanisms of Fosfomycin Resistance in Clinical Escherichia coli Isolates in Mainland China.

    Directory of Open Access Journals (Sweden)

    Ya Li

    Full Text Available Escherichia coli is one of the most common pathogens in nosocomial and community-acquired infections in humans. Fosfomycin is a broad-spectrum antibiotic which inhibits peptidoglycan synthesis responsible for bacterial cell wall formation. Although low, the exact E. coli susceptibility to fosfomycin as well as the mechanisms of resistance in the population from Mainland China are mostly unknown. 1109 non-duplicate clinical E. coli strains isolated from urine, sputum, blood and pus samples in 20 widely dispersed tertiary hospitals from Mainland China were collected from July 2009 to June 2010, followed by determination of minimum inhibitory concentrations of fosfomycin. Detection of the murA, glpT, uhpT, fosA, fosA3 and fosC genes was performed in fosfomycin non-susceptible E. coli strains and conjugation experiments were employed to determine the mobility of fosA3 gene. In this study, 7.8% (86/1109 E. coli strains were fosfomycin non-susceptible. Amino acid substitutions in GlpT and MurA were found in six and four E.coli strains, respectively, while the uhpT gene was absent in eighteen E.coli strains. Twenty-nine isolates carried the transferable plasmid with the fosA3 gene at high frequencies of around 10(-6 to 10(-7 per donor cell in broth mating. The majority of isolates were susceptible to fosfomycin, showing that the drug is still viable in clinical applications. Also, the main mechanism of E. coli resistance in Mainland China was found to be due to the presence of the fosA3 gene.

  17. Rapid identification and differentiation of clinical isolates of enteropathogenic Escherichia coli (EPEC), atypical EPEC, and Shiga toxin-producing Escherichia coli by a one-step multiplex PCR method

    NARCIS (Netherlands)

    Müller, Daniel; Hagedorn, Peter; Brast, Sabine; Heusipp, Gerhard; Bielaszewska, Martina; Friedrich, Alexander W; Karch, Helge; Schmidt, M Alexander

    2006-01-01

    Enteropathogenic Escherichia coli (EPEC), atypical enteropathogenic E. coli, and Shiga toxin-producing E. coli differ in their virulence factor profiles, clinical manifestations, and prognosis, and they require different therapeutic measures. We developed and evaluated a robust multiplex PCR to iden

  18. Antimicrobial resistance trends among canine Escherichia coli isolates obtained from clinical samples in the northeastern USA, 2004–2011

    OpenAIRE

    Cummings, Kevin J.; Aprea, Victor A.; Altier, Craig

    2015-01-01

    Our objectives were to describe the antimicrobial susceptibility of Escherichia coli isolates from dogs in the northeastern USA and to identify temporal trends in resistance to selected antimicrobial agents. Data were collected retrospectively for all canine E. coli isolates from clinical samples submitted to Cornell University’s Animal Health Diagnostic Center between January 1, 2004 and December 31, 2011. Antimicrobial susceptibility testing was performed on 3519 canine E. coli isolates; fr...

  19. Bactericidal activity of Musca domestica cecropin (Mdc) on multidrug-resistant clinical isolate of Escherichia coli.

    Science.gov (United States)

    Lu, X; Shen, J; Jin, X; Ma, Y; Huang, Y; Mei, H; Chu, F; Zhu, J

    2012-08-01

    The housefly (Musca domestica) larvae have been used clinically to cure osteomyelitis, decubital necrosis, lip boil, ecthyma and malnutritional stagnation ever since the Ming/Qing Dynasty (1368 Anno Domini) till now, in China. In prior research, we have cloned and characterized a new gene of antimicrobial peptide cecropin from M. domestica larvae. This peptide was potently active against Gram-positive and Gram-negative bacteria standard strain. In the present study, we evaluated the possibility of Mdc to be a potential bactericidal agent against clinical isolates of multidrug-resistant (MDR) Escherichia coli and to elucidate the related antimicrobial mechanisms. Antimicrobial activity assays indicated a minimal inhibitory concentration (MIC) of 1.56 μM. Bactericidal kinetics at MIC showed that Mdc rapid killing of MDR E. coli. Lipopolysaccharide (LPS) dose-dependently suppressed Mdc antibacterial potency indicates that LPS is the initial binding site of Mdc in E. coli. Propidium iodide-based flow cytometry revealed that Mdc causes E. coli membrane permeabilization. Transmission electron micrographs further indicated that a remarkable damage in the bacteria's outer and inner membrane, even the leakage of cytoplasmic contents induced by Mdc. DNA binding experimental result implies that DNA is one of the possible intracellular targets of Mdc. Of note, Mdc did not show a perceptible cytotoxic effect on human red blood cells. Altogether, these results suggest that Mdc could be an excellent candidate for the development of more efficacious bactericidal agents. PMID:22202966

  20. Molecular Characteristics of Extended-Spectrum β-Lactamases in Clinical Isolates from Escherichia coli at a Japanese Tertiary Hospital

    OpenAIRE

    Yano, Hisakazu; Uemura, Mina; Endo, Shiro; Kanamori, Hajime; Inomata, Shinya; Kakuta, Risako; Ichimura, Sadahiro; Ogawa, Miho; Shimojima, Masahiro; Ishibashi, Noriomi; Aoyagi, Tetsuji; Hatta, Masumitsu; Gu, Yoshiaki; Yamada, Mitsuhiro; Tokuda, Koichi

    2013-01-01

    The prevalence of ESBL has been increasing worldwide. In this study, we investigated the molecular characteristics of ESBL among clinical isolates of Escherichia coli from a Japanese tertiary hospital. A total of 71 consecutive and nonduplicate clinical isolates of ESBL-positive E. coli collected at Tohoku University Hospital between January 2008 and March 2011 were studied. The antimicrobial susceptibility profile of these strains was determined. PCR and sequencing were performed to identify...

  1. Phenotypic and Genotypic Characterization of Enterotoxigenic Escherichia coli Clinical Isolates from Northern Colombia, South America

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    Julio A. Guerra

    2014-01-01

    Full Text Available Enterotoxigenic Escherichia coli (ETEC are major causes of childhood diarrhea in low and middle income countries including Colombia, South America. To understand the diversity of ETEC strains in the region, clinical isolates obtained from northern Colombia children were evaluated for multiple locus sequencing typing, serotyping, classical and nonclassical virulence genes, and antibiotic susceptibility. Among 40 ETEC clinical isolates evaluated, 21 (52.5% were positive for LT gene, 13 (32.5% for ST gene, and 6 (15% for both ST and LT. The most prevalent colonization surface antigens (CS were CS21 and CFA/I identified in 21 (50% and 13 (32.5% isolates, respectively. The eatA, irp2, and fyuA were the most common nonclassical virulence genes present in more than 60% of the isolates. Ampicillin resistance (80% of the strains was the most frequent phenotype among ETEC strains followed by trimethoprim-sulfamethoxazole resistance (52.5%. Based on multiple locus sequencing typing (MLST, we recognize that 6 clonal groups of ETEC clinical isolates circulate in Colombia. ETEC clinical isolates from children in northern Colombia are highly diverse, yet some isolates circulating in the community belong to well-defined clonal groups that share a unique set of virulence factors, serotypes, and MLST sequence types.

  2. Antimicrobial Susceptibility Pattern of Clinical Isolates of Escherichia coli and Proteus mirabilis Using Cefepime in Ogbomoso, Nigeria.

    OpenAIRE

    Oladipo E Kolawole; Amao J. A.; Omomowo I. O.; Agboola J. O.; Afolabi A. Y.; Akinade B. S.

    2014-01-01

    The challenge of Cefepime resistance in developing countries is substantial and likely to grow. Emergence of Cefepime-resistant bacteria has increased and management of this has become a therapeutic challenge. The production of beta lactamases by most bacteria make them to be resistant to beta lactam antibiotics like Cefepime which is common nowadays. Forty clinical isolates of Escherichia coli and Proteus mirabilis from different clinical sites were analyzed between March and August, 2013 u...

  3. Characterization of CTX-M ESBLs in Enterobacter cloacae, Escherichia coli and Klebsiella pneumoniae clinical isolates from Cairo, Egypt

    OpenAIRE

    Khalaf Noha G; Eletreby Mona M; Hanson Nancy D

    2009-01-01

    Abstract Background A high rate of resistance to 3rd generation cephalosporins among Enterobacteriaceae isolates from Egypt has been previously reported. This study aims to characterize the resistance mechanism (s) to extended spectrum cephalosporins among resistant clinical isolates at a medical institute in Cairo, Egypt. Methods Nonconsecutive Klebsiella pneumoniae (Kp), Enterobacter cloacae (ENT) and Escherichia coli (EC) isolates were obtained from the clinical laboratory at the medical i...

  4. Recurrent Escherichia coli bacteremia.

    Science.gov (United States)

    Maslow, J N; Mulligan, M E; Arbeit, R D

    1994-01-01

    Escherichia coli is the most common gram-negative organism associated with bacteremia. While recurrent E. coli urinary tract infections are well-described, recurrent E. coli bacteremia appears to be uncommon, with no episodes noted in multiple series of patients with gram-negative bacteremias. We report on 5 patients with recurrent bloodstream infections identified from a series of 163 patients with E. coli bacteremia. For each patient, the isolates from each episode were analyzed by pulsed-field gel electrophoresis (PFGE) and ribotyping and for the presence of E. coli virulence factors. For each of four patients, the index and recurrent episodes of bacteremia represented the same strain as defined by PFGE, and the strains were found to carry one or more virulence factors. The remaining patient, with two episodes of bloodstream infection separated by a 4-year interval, was infected with two isolates that did not carry any virulence factors and that were clonally related by ribotype analysis but differed by PFGE. All five patients had either a local host defense defect (three patients) or impaired systemic defenses (one patient) or both (one patient). Thus, recurrent E. coli bacteremia is likely to represent a multifactorial process that occurs in patients with impaired host defenses who are infected with virulent isolates. Images PMID:7910828

  5. Identification of a novel ampC beta-lactamase promoter in a clinical isolate of Escherichia coli.

    OpenAIRE

    O. Olsson; Bergström, S; Normark, S

    1982-01-01

    A clinical strain of Escherichia coli, C16, that overproduces the ampC beta-lactamase was isolated. A 203-bp DNA segment from this strain, including the promoter and attenuator region of the ampC structural gene, was sequenced. A comparison with the corresponding sequence of E. coli K12 revealed four base pair differences between the ampC segments from these strains. DNA sequence data and in vitro transcription indicated that the ampC promoter in the clinical isolate was displaced 5 bp upstre...

  6. Clonal spread and interspecies transmission of clinically relevant ESBL-producing Escherichia coli of ST410--another successful pandemic clone?

    Science.gov (United States)

    Schaufler, Katharina; Semmler, Torsten; Wieler, Lothar H; Wöhrmann, Michael; Baddam, Ramani; Ahmed, Niyaz; Müller, Kerstin; Kola, Axel; Fruth, Angelika; Ewers, Christa; Guenther, Sebastian

    2016-01-01

    Clinically relevant extended-spectrum beta-lactamase (ESBL)-producing multi-resistant Escherichia coli have been on the rise for years. Initially restricted to mostly a clinical context, recent findings prove their prevalence in extraclinical settings independent of the original occurrence of antimicrobial resistance in the environment. To get further insights into the complex ecology of potentially clinically relevant ESBL-producing E. coli, 24 isolates from wild birds in Berlin, Germany, and 40 ESBL-producing human clinical E. coli isolates were comparatively analyzed. Isolates of ST410 occurred in both sample groups (six). In addition, three ESBL-producing E. coli isolates of ST410 from environmental dog feces and one clinical dog isolate were included. All 10 isolates were clonally analyzed showing almost identical macrorestriction patterns. They were chosen for whole-genome sequencing revealing that the whole-genome content of these 10 E. coli isolates showed a very high genetic similarity, differing by low numbers of single nucleotide polymorphisms only. This study gives initial evidence for a recent interspecies transmission of a new successful clone of ST410 E. coli between wildlife, humans, companion animals and the environment. The results underline the zoonotic potential of clinically relevant multi-resistant bacteria found in the environment as well as the mandatory nature of the 'One Health' approach. PMID:26656065

  7. Human intestinal cells modulate conjugational transfer of multidrug resistance plasmids between clinical Escherichia coli isolates.

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    Ana Manuel Dantas Machado

    Full Text Available Bacterial conjugation in the human gut microbiota is believed to play a major role in the dissemination of antibiotic resistance genes and virulence plasmids. However, the modulation of bacterial conjugation by the human host remains poorly understood and there is a need for controlled systems to study this process. We established an in vitro co-culture system to study the interaction between human intestinal cells and bacteria. We show that the conjugation efficiency of a plasmid encoding an extended spectrum beta-lactamase is reduced when clinical isolates of Escherichia coli are co-cultured with human intestinal cells. We show that filtered media from co-cultures contain a factor that reduces conjugation efficiency. Protease treatment of the filtered media eliminates this inhibition of conjugation. This data suggests that a peptide or protein based factor is secreted on the apical side of the intestinal cells exposed to bacteria leading to a two-fold reduction in conjugation efficiency. These results show that human gut epithelial cells can modulate bacterial conjugation and may have relevance to gene exchange in the gut.

  8. Distribution of tccP in Clinical Enterohemorrhagic and Enteropathogenic Escherichia coli Isolates‡

    OpenAIRE

    Garmendia, Junkal; Ren, Zhihong; Tennant, Sharon; Midolli Viera, Monica Aparecida; Chong, Yuwen; Whale, Andrew; Azzopardi, Kristy; Dahan, Sivan; Sircili, Marcelo Palma; Franzolin, Marcia Regina; Trabulsi, Luiz R.; Phillips, Alan; Gomes, Tânia A. T.; Xu, Jianguo; Robins-Browne, Roy

    2005-01-01

    Enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) are diarrheagenic pathogens that colonize the gut through the formation of attaching and effacing lesions, which depend on the translocation of effector proteins via a locus of enterocyte effacement-encoded type III secretion system. Recently, two effector proteins, EspJ and TccP, which are encoded by adjacent genes on prophage CP-933U in EHEC O157:H7, have been identified. TccP consists of a unique N-terminus regio...

  9. SHV-5 extended-spectrum beta-lactamases in clinical isolates of Escherichia coli in Malaysia

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    Subramaniam G

    2006-01-01

    Full Text Available Escherichia coli isolates resistant to ceftazidime isolated in the University Malaya Medical Center (UMMC Kuala Lumpur, Malaysia, between the years 1998 and 2000 were studied for extended-spectrum β -lactamase (ESBL production. All strains were analysed phenotypically and genotypically and found to be ESBL-producing organisms harbouring SHV-5 β-lactamase. This was confirmed by PCR-SSCP and nucleotide sequencing of the blaSHV amplified gene. As there was no evidence of ESBL activity in E. coli prior to this, coupled with the fact that there was a predominance of SHV-5 β-lactamases in Klebsiella pneumoniae isolates in UMMC, we postulate that the E. coli obtained the SHV-5 β-lactamase genes by plasmid transfer from the ESBL-producing K. pneumoniae.

  10. Epidemiological and clinical features for cefepime heteroresistant Escherichia coli infections in Southwest China.

    Science.gov (United States)

    Ma, W; Sun, J; Yang, S; Zhang, L

    2016-04-01

    Phenotypic heteroresistance (PHR) is common in a weight of microbes and plays an important role in the evolution of antibiotic resistance. However, PHR to cefepime (FEP-PHR) among invasive Escherichia coli (E. coli) has not been reported. This study aimed to report the characteristics of invasive E. coli with FEP-PHR traits and further to investigate the predisposing factors for its acquisition. A retrospective case-control study was conducted in a teaching hospital in Southwest China. A total of 319 successive and non-duplicate E. coli strains were isolated from blood and other sterile body fluids between July 2011 and August 2013. Among the seventy (70/319, 21.9 %) isolates harboring FEP-PHR traits, 30 (42.9 %) isolates were isolated from blood, 14 (20.0 %) isolates were isolated from bile, and 13 (18.6 %) isolates were isolated from drainage. FEP-PHR isolates were verified by population analysis profile (PAP) assays. Male gender, receipt of total parenteral nutrition, cephalosporins exposure, and production of extended spectrum betalactamases (ESBL) were independent risk factors for the acquisition of invasive E. coli with FEP-PHR traits. Pulsedfield gel electrophoresis (PFGE) revealed clonal diversity among the FEP-PHR isolates. The prevalence of heteroresistance to cefepime among invasive E. coli isolates merits great attention and heteroresistance may lead to the emergence of resistance strains. Therefore, systematical analysis of risk factors, careful interpretation of antibiotic susceptibility results and appropriate prescription of therapeutic strategy could help to prevent misreporting and therapeutic failure. PMID:26815433

  11. Molecular characterization of integrons in clinical isolates of betalactamase-producing Escherichia coli and Klebsiella pneumoniae in Iran.

    Science.gov (United States)

    Zeighami, Habib; Haghi, Fakhri; Hajiahmadi, Fahimeh

    2015-06-01

    Integrons are considered to play a significant role in the evolution and spread of antibiotic resistance genes. A total of 349 clinical isolates of Escherichia coli and Klebsiella pneumoniae were investigated for molecular characterization of integrons and betalactamases. Antimicrobial susceptibility testing was also performed as the Clinical and Laboratory Standards Institute (CLSI) guidelines. The frequency of extended spectrum betalactamases (ESBL) or metallo-betalactamases (MBL)-producing isolates, patient demographics, and the susceptibility to various antimicrobial agents were described. BlaCTX-M was the most frequently detected betalactamase in all isolates. Moreover, MBL producing K. pneumoniae carried blaIMP and blaVIM at 100 and 41·6%, respectively but no MBL-positive E. coli was detected. Class 1 integrons were more frequent among E. coli and K. pneumoniae isolates in comparison with class 2 integrons and the frequency of intI2 in K. pneumoniae was significantly higher than E. coli isolates. Five different resistance gene arrays were identified among class 1 integrons. Dihydrofolate reductase (dfrA) and aminoglycoside adenyltransferase (aad) gene cassettes were found to be predominant in the class 1 integrons. These results indicate that class 1 integrons are widespread among ESBL-producing isolates of K. pneumoniae and E. coli and appropriate surveillance and control measures are essential to prevent further dissemination of these elements among Enterobacteriaceae in our country. PMID:24571248

  12. Genotypic and phenotypic comparison of Escherichia coli from uterine infections with different outcomes: clinical metritis in the cow and pyometra in the bitch.

    Science.gov (United States)

    Henriques, Sofia; Silva, Elisabete; Lemsaddek, Abdelhak; Lopes-da-Costa, Luís; Mateus, Luisa

    2014-05-14

    Escherichia coli uterine infection originates different clinical outcomes in the canine and bovine species. Here, E. coli strains isolated from bovine clinical metritis and canine pyometra cases were analyzed by PFGE, screened for 33 virulence factor (VF) genes and for phylogenetic grouping. Bovine and canine E. coli isolates presented a low degree of genetic similarity. Canine E. coli strains belonged to phylogenetic group B2 and presented a high number of VF genes, whereas bovine E. coli strains belonged to phylogenetic groups B1 and A and had a low number of VF genes. In conclusion, E. coli strains isolated from cow clinical metritis had a low potential of virulence. In contrast, bitch pyometra E. coli isolates had a high virulence potential, which might be relevant in the pathogenesis of pyometra. These differences between canine and bovine E. coli isolates may partially explain the different outcomes of the uterine infection in the two species. PMID:24598134

  13. Escherichia coli Uropathogenesis In Vitro

    DEFF Research Database (Denmark)

    Andersen, Thomas E; Khandige, Surabhi; Madelung, Michelle;

    2012-01-01

    Uropathogenic Escherichia coli (UPEC) strains are capable of invading bladder epithelial cells (BECs) on the bladder luminal surface. Based primarily on studies in mouse models, invasion is proposed to trigger an intracellular uropathogenic cascade involving intracellular bacterial proliferation...

  14. Fluoroquinolone-resistance mechanisms and phylogenetic background of clinical Escherichia coli strains isolated in south-east Poland.

    Science.gov (United States)

    Korona-Glowniak, Izabela; Skrzypek, Kinga; Siwiec, Radosław; Wrobel, Andrzej; Malm, Anna

    2016-09-01

    Fluorochinolones are a class of broad-spectrum antimicrobials in the treatment of several infections, including those caused by Escherichia coli. Due to the increasing resistance of bacteria to antimicrobials, an understanding of fluoroquinolone resistance is important for infection control. The aim of this study was to determine susceptibility of clinical E. coli strains to fluoroquinolones and characterize their mechanisms of quinolone resistance. Totally, 79 non-duplicate clinical E. coli isolates included in this study were mainly from skin lesion -36 (45.6%) isolates; 54 (68.4%) isolates were assigned to phylogenetic B2 group. Resistance to ciprofloxacin was found in 20 isolates. In the quinolone resistance-determining region (QRDR) region of gyrA and parC, 4 types of point mutations were detected. Mutations in parC gene were found in all strains with gyrA mutations. Predominance of double mutation in codon 83 and 87 of gyrA (90%) and in codon 80 of parC (90%) was found. Moreover, plasmid-mediated quinolone resistance (PMRQ) determinants (qnrA or qnrB and/or aac(6')-Ib-cr) were present in 5 (25%) out of 20 fluoroquinolone-resistant isolates. Resistance to fluoroquinolones in all of the tested clinical E. coli isolates correlated with point mutations in both gyrA and parC. The majority of fluoroquinolone-resistant strains belonged to D and B2 phylogenetic groups. PMID:27602420

  15. Molecular Characterization of Resistance to Extended-Spectrum Cephalosporins in Clinical Escherichia coli Isolates from Companion Animals in the United States ▿ †

    OpenAIRE

    Shaheen, Bashar W.; Nayak, Rajesh; Foley, Steven L.; Kweon, Ohgew; Deck, Joanna; Park, Miseon; Rafii, Fatemeh; Boothe, Dawn M.

    2011-01-01

    Resistance to extended-spectrum cephalosporins (ESC) among members of the family Enterobacteriaceae occurs worldwide; however, little is known about ESC resistance in Escherichia coli strains from companion animals. Clinical isolates of E. coli were collected from veterinary diagnostic laboratories throughout the United States from 2008 to 2009. E. coli isolates (n = 54) with reduced susceptibility to ceftazidime or cefotaxime (MIC ≥ 16 μg/ml) and extended-spectrum-β-lactamase (ESBL) phenotyp...

  16. Cefoxitin resistance mediated by loss of a porin in clinical strains of Klebsiella pneumoniae and Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ananthan S

    2005-01-01

    Full Text Available PURPOSE: Porins are outer membrane protein (OMP that form water filled channels that permit the diffusion of small hydrophilic solutes like -lactam antibiotics across the outer membrane. Two major porins that facilitate diffusion of antimicrobials have been described in Klebsiella spp. and Escherichia coli. The present study was carried out to examine the role of porins among Extended Spectrum -Lactamase (ESBL and AmpC -Lactamase positive strains of Klebsiella spp. and E.coli. METHODS: Preparation of OMP from phenotypically characterized clinical isolates K.pneumoniae and E.coli and the separation of the proteins by sodium dodecyl sulfate - polyacrylamide gel electrophoresis were performed as per a previously described procedure. RESULTS: OMP analysis revealed that cefoxitin and ceftazidime resistance was mediated by loss of a porin Omp K35 in the isolates of K.pneumoniae and E.coli. CONCLUSIONS: Loss of porin mediated resistance mechanism against cefoxitin was observed among the multidrug resistant K.pneumoniae and E.coli.

  17. Antibacterial activity of honey against clinical isolates of Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica serovar Typhi

    Institute of Scientific and Technical Information of China (English)

    Shyamapada Mandal; Manisha DebMandal; Nishith Kumar Pal; Krishnendu Saha

    2010-01-01

    Objective: To ascertain the potential antibacterial activity of honey against clinical isolates ofEscherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Salmonella enterica serovar Typhi (S. enterica serovar Typhi) by in vitro methods. Methods: The partial inhibitory concentration (PIC), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the autoclaved honey (extracted from Apis indica hive by indigenous method) were determined for S. enterica serovar Typhi (n=8; from blood cultute),E. coli (n=5; from urine culture) and P. aeruginosa (n=5; from pus culture) isolates by in vitro methods. Results: The PICs of the honey tested for the isolates ranged 0.50%-1.25 % (v/v) for S. enterica serovar Typhi, 0.75%-1.50% (v/v) for E. coli and 1.00%-1.25 % (v/v) for P. aeruginosa, while the MICs ranged 1.75%-3.00% (v/v), 3.00%-3.50% (v/v) and 3.50% (v/v), respectively. The P. aeruginosa and E. coli isolates had MBC value of 4.00% (v/v); the S. enterica serovar Typhi showed MBCs in between 3.00% and 3.50% (v/v). The bactericidal activity of honey was achieved at concentration 3.00% (v/v) for S. enterica serovar Typhi and E. coli, and at 3.50% (v/v) for P. aeruginosa. Conclusions: The excellent antibacterial activity of honey against clinical bacterial isolates indicates the usefulness of honey in clinical practice against bacterial infection.

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

    Directory of Open Access Journals (Sweden)

    Ibeh Nnana Isaiah

    2011-01-01

    Full Text Available 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 profile of the isolates against 10 different antibiotics was examined, the MICs (Minimum Inhibitory Concentration for ceftazidime were also determined using micro-broth dilution assay. Isolates showing MIC ≥ 6 μg/ml for ceftazidime were screened for ESBL (PCTphenotypic confirmatory test and subjected to PCR (polymerase chain reaction to further. Results: By disk diffusion test, there was resistance to ceftazidime and cefotaxime were 180(51.4% and 120 (34.2% respectively. However, all strains were susceptible to imipenem. 250 isolates showed MICs≥ 6 μg/ml for ceftazidime of which 180 (72% were positive for extended spectrum beta lactamase. The prevalence of Sulphurhydryl variable, Temonera and the Cefotaximase among these isolates were 17.1%, 6.6% and 17%, respectively. Conclusion: For the identification of extended spectrum beta lactamase producing isolates it is recommended that clinical laboratories adopt simple test based on Cinical laboratory standard institute recommendation for confirming extended spectrum beta lactamase production in enterobacteriacea species.

  19. Variation in Resistance Traits, Phylogenetic Backgrounds, and Virulence Genotypes among Escherichia coli Clinical Isolates from Adjacent Hospital Campuses Serving Distinct Patient Populations

    OpenAIRE

    Drawz, Sarah M.; Porter, Stephen; Kuskowski, Michael A.; Johnston, Brian; Clabots, Connie; Kline, Susan; FERRIERI, PATRICIA; Johnson, James R.

    2015-01-01

    Escherichia coli sequence type 13 (ST131), an emergent cause of multidrug-resistant extraintestinal infections, has important phylogenetic subsets, notably the H30 and H30Rx subclones, with distinctive resistance profiles and, possibly, clinical associations. To clarify the local prevalence of these ST131 subclones and their associations with antimicrobial resistance, ecological source, and virulence traits, we extensively characterized 233 consecutive E. coli clinical isolates (July and Augu...

  20. Clinical Epidemiology and Molecular Analysis of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Nepal: Characteristics of Sequence Types 131 and 648

    OpenAIRE

    Sherchan, Jatan Bahadur; Hayakawa, Kayoko; Miyoshi-Akiyama, Tohru; Ohmagari, Norio; Kirikae, Teruo; Nagamatsu, Maki; Tojo, Masayoshi; Ohara,Hiroshi; Sherchand, Jeevan B; Tandukar, Sarmila

    2015-01-01

    Recently, CTX-M-type extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli strains have emerged worldwide. In particular, E. coli with O antigen type 25 (O25) and sequence type 131 (ST131), which is often associated with the CTX-M-15 ESBL, has been increasingly reported globally; however, epidemiology reports on ESBL-producing E. coli in Asia are limited. Patients with clinical isolates of ESBL-producing E. coli in the Tribhuvan University teaching hospital in Kathmandu, Nepal, were...

  1. High diversity of plasmids harbouring blaCMY-2 among clinical Escherichia coli isolates from humans and companion animals in the upper Midwestern USA

    DEFF Research Database (Denmark)

    Bortolaia, Valeria; Hansen, Katrine Hartung; Nielsen, Christine;

    2014-01-01

    To determine the population structure and genetic relatedness of plasmids encoding CMY-2 β-lactamase in clinical Escherichia coli from humans and companion animals within a defined geographical area.......To determine the population structure and genetic relatedness of plasmids encoding CMY-2 β-lactamase in clinical Escherichia coli from humans and companion animals within a defined geographical area....

  2. Unreliable Extended-Spectrum β-Lactamase Detection in the Presence of Plasmid-Mediated AmpC in Escherichia coli Clinical Isolates▿

    OpenAIRE

    Robberts, F. J. L.; Kohner, P C; Patel, R.(Rutgers, The State University of New Jersey, Piscataway, USA)

    2008-01-01

    The emergence of extended-spectrum β-lactamase (ESBL) and plasmid-mediated AmpC (pAmpC) enzymes in Escherichia coli raises concern regarding accurate laboratory detection and interpretation of susceptibility testing results. Twenty-six cefpodoxime ESBL screen-positive, cefoxitin-resistant E. coli clinical isolates were subjected to clavulanate ESBL confirmatory testing employing disk augmentation, Etest, and the BD Phoenix NMC/ID-132 panel. Phenotypic pAmpC production was assessed by boronic ...

  3. Class 1 integrons contributes to antibiotic resistance among clinical isolates of Escherichia coli producing extended-spectrum beta-lactamases

    Directory of Open Access Journals (Sweden)

    T Chen

    2013-01-01

    Full Text Available Objectives: The objective of this study is to determine the prevalence of antibiotic resistance factors, including the production of extended-spectrum beta-lactamases (ESBLs and the presence of class 1 integrons among Escherichia coli isolated from clinical specimens. Materials and Methods: Bacterial species identification was performed using a VITEK-2 system (VITEK2 GN-card; bioMérieux, France. Antimicrobial susceptibility testing was determined using the disk diffusion method according to the 2010 Clinical and Laboratory Standards Institute guidelines. Polymerase chain reaction (PCR was used to detect integrons and amplify variable regions of the bla TEM, bla SHV and bla CTX-M genes. Gene cassettes were detected by deoxyribonucleic acid sequencing. Results: In this study, 58% (100/172 of clinical E. coli isolates were identified as ESBL producers. We found that 90% of the ESBL-producing E. coli isolates harbored the blaCTX-M gene, whereas only 59% and 32% possessed the blaTEM and blaSHV genes respectively. The presence of class 1 integrons was based on the detection of the integrase gene by PCR. A total of 69% of the ESBL-producing isolates were integron-positive. Resistance to 10 antibiotics, including quinolones, sulfonamides and β-lactam/enzyme inhibitors, was significantly higher in the class 1 integron-positive isolates (P < 0.05. The occurrence of class 1 integrons in blaTEM , blaSHV and blaCTX-M gene carriers was 72.9%, 84.4% and 68.9%, respectively. Class 1 integrons were detected in 61.5% of the isolates with only one ESBL genotype, but in 69.0% and 92.3% of the isolates with two or three different ESBL genotypes, respectively. Conclusions: Our findings indicate that clinical strains of bacteria with multiple ESBL genotypes may have greater opportunities to carry class 1 integrons.

  4. 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...

  5. Fleroxacin resistance in Escherichia coli.

    OpenAIRE

    Chapman, J S; Bertasso, A; Georgopapadakou, N H

    1989-01-01

    Spontaneous fleroxacin-resistant mutants of Escherichia coli K-12 were isolated at a frequency of 10(-10) to 10(-11) mutants per CFU plated. All mutants exhibited quinolone-resistant replicative DNA biosynthesis, and 4 of 11 mutants also had decreased amounts of OmpF or OmpC porin. None of the mutants had changes solely in porin proteins.

  6. Molecular characterisation of acquired and overproduced chromosomal blaAmpC in Escherichia coli clinical isolates.

    Science.gov (United States)

    Alonso, Noemí; Miró, Elisenda; Pascual, Vanesa; Rivera, Alba; Simó, Maria; Garcia, Maria Consol; Xercavins, Mariona; Morera, Maria Antonia; Espejo, Elena; Gurguí, Mercè; Pérez, Josefa; Rodríguez-Carballeira, Mònica; Garau, Javier; Calbo, Esther; Navarro, Ferran; Mirelis, Beatriz; Coll, Pere

    2016-01-01

    Escherichia coli recovered from three hospitals in Barcelona (Spain) were studied to determine the prevalence of isolates with acquired AmpC (ac-AmpC) and/or overproduced chromosomal AmpC (c-AmpC). Mechanisms involved in blac-AmpC overexpression, blaac-AmpC and the plasmids associated with their distribution as well as the prevalence of plasmid-mediated quinolone resistance (PMQR) in AmpC-producing isolates were also determined. Isolates were selected according to their resistance phenotype. blaac-AmpC, alterations in the blac-AmpC promoter/attenuator, and PMQR genes [qnrA, qnrB, qnrS, aac(6')-Ib-cr and qepA] were characterised by PCR and sequencing. blac-AmpC expression was determined by qRT-PCR. Population structure analysis was performed using PFGE, MLST and phylogenetic group PCR. Plasmids carrying blaac-AmpC were characterised by PCR-based replicon typing and S1-PFGE. IncI1 and IncF plasmids were also analysed by plasmid MLST and replicon sequence typing, respectively. Among 21563 E. coli isolates, 240 (1.1%) overproduced AmpC β-lactamases, including 180 (75.0%) harbouring ac-AmpC (132 CMY-2 variants and 48 DHA-1) and 60 (25.0%) c-AmpC enzymes. Three mutation profiles in the blac-AmpC promoter/attenuator were associated with a 72.5-, 19.9- and 5.8-fold increased expression, respectively. Moreover, 63.3% of ac-AmpC and 43.3% of c-AmpC isolates belonged to B2, D, E or F phylogenetic groups. PMQR was found in 31% of ac-AmpC isolates [38 qnrB4, 8 aac(6')-Ib-cr, 6 qnrS1 and 3 qnrB19] and in 10% of c-AmpC isolates [5 aac(6')-Ib-cr and 1 qnrS1]. IncI1-ST12 and IncF were associated with blaCMY-2 and blaDHA-1, respectively. These results suggest that ac-AmpC β-lactamases were the main mechanism of AmpC production. Isolates and plasmids both showed high genetic diversity. PMID:26607336

  7. Underlying Mechanism of In vivo and In vitro Activity of C-terminal–amidated Thanatin Against Clinical Isolates of Extended-Spectrum β-lactamase–Producing Escherichia coli

    OpenAIRE

    Hou, Zheng; Lu, Jun; Fang, Chao; Zhou, Ying; Bai, Hui; Zhang, Xiaogong; Xue, Xiaoyan; Chen, Yingying; Luo, Xiaoxing

    2011-01-01

    Background. Infections with extended-spectrum β-lactamase–producing Escherichia coli (ESBL-EC) have developed resistance to current therapies. Therefore, the underlying mechanisms of in vivo and in vitro activity of C-terminal–amidated thanatin (A-thanatin) against clinical isolates of ESBL-EC were studied in an attempt to resolve this problem.

  8. Escherichia coli in Europe: An Overview

    Directory of Open Access Journals (Sweden)

    Nerino Allocati

    2013-11-01

    Full Text Available Escherichia coli remains one of the most frequent causes of several common bacterial infections in humans and animals. E. coli is the prominent cause of enteritis, urinary tract infection, septicaemia and other clinical infections, such as neonatal meningitis. E. coli is also prominently associated with diarrhoea in pet and farm animals. The therapeutic treatment of E. coli infections is threatened by the emergence of antimicrobial resistance. The prevalence of multidrug-resistant E. coli strains is increasing worldwide principally due to the spread of mobile genetic elements, such as plasmids. The rise of multidrug-resistant strains of E. coli also occurs in Europe. Therefore, the spread of resistance in E. coli is an increasing public health concern in European countries. This paper summarizes the current status of E. coli strains clinically relevant in European countries. Furthermore, therapeutic interventions and strategies to prevent and control infections are presented and discussed. The article also provides an overview of the current knowledge concerning promising alternative therapies against E. coli diseases.

  9. Surveillance and Detection of Inhibitor-Resistant Beta-Lactamases in Clinical Isolates of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Carl Urban

    2007-06-01

    Full Text Available In recent years, resistance to beta-lactam antibiotics, such as the widely-used cephalosporins and penicillins, has become a major challenge for disease therapy, particularly in common hospital-acquired infections. In the search for the mechanisms behind this increasingly prevalent form of resistance, microbiologists have identified a new type of beta-lactamase enzyme, called inhibitor-resistant TEMs (IRTs, which can withstand the effects of beta-lactamase inhibitor compounds, further reducing the arsenal of drugs available to physicians facing resistant bacteria. In this study, we examined the enzymatic and genetic basis of Escherichia coli isolates demonstrating such resistance to beta-lactam/beta-lactamase inhibitor combinations. Susceptibility trials played a major role in composing the experimental cohort for this project (n=50; each isolate was thoroughly tested to ensure that it was resistant to ampicillin-sulbactam, an inhibitor combination, but susceptible to the third-generation cephalosporin ceftazidime. Subsequently, a number of samples were subjected to assay by pulsed-field gel electrophoresis (n=18 and polymerase chain reaction (n=3 so that their genetic composition and relatedness might be known. In particular, the presence of genes coding for TEM-type beta-lactamases was investigated for each of the 3 isolates sequenced. Even though it was anticipated that the isolates would possess resistance to inhibitor combinations due to an IRT gene, this was not found to be the case. Instead, the mechanism of resistance turned out to be over-expression of a gene coding for a normal TEM enzyme. The results of these experiments have implications for ensuring successful therapy of bacterial infections and for preventing the spread of antimicrobial resistance.

  10. Incidence and impact on clinical outcome of infections with piperacillin/tazobactam resistant Escherichia coli in ICU: A retrospective study

    Directory of Open Access Journals (Sweden)

    Mounier Roman

    2008-05-01

    Full Text Available Abstract Background Escherichia coli infections are frequent in ICU patients. The increased resistance to fluoroquinolones and amoxicillin/clavulanate of this pathogen mandates the prescription of broad-spectrum antibiotics such as piperacillin/tazobactam (PIP-TAZ or third generation cephalosporins (3GC. Methods To assess incidence and impact on clinical outcome of infections with PIP-TAZ resistant E. coli in ICU patients, we conducted a retrospective cohort study with infections due to PIP-TAZ resistant (PIP-TAZ R or to PIP-TAZ susceptible strains (PIP-TAZ S between 1 January 2002 and 30 June 2004. Results Of 83 strains, 13 were PIP-TAZ R: 2 strains produced an extended-spectrum β-lactamase (2%, 11 produced a high level penicillinase (13%. Prior amoxicillin or amoxicillin/clavulanate prescription was reported in 7 cases (54% of infections with PIP-TAZ R isolates and in 15 cases (21% of infections with PIP-TAZ S isolates (p = 0.03. Time of onset of the infection from hospital admission was longer in case of infections with PIP-TAZ R than with PIP-TAZ S isolates (22 ± 32 vs 10 ± 21 days, p = 0.01. The overall ICU mortality rate was 38%. Mortality and length of stay in ICU were similar in case of infections with PIP-TAZ R isolates and with PIP-TAZ S isolates. Conclusion Infections with PIP-TAZ R E. coli are frequent in ICU patients. No prognostic impact of this pattern of resistance was found. Prescription of PIP-TAZ for empirical treatment of E. coli infections in ICU however exposes to inappropriate therapy.

  11. Molecular characteristics of extended-spectrum β-lactamases in clinical isolates from Escherichia coli at a Japanese tertiary hospital.

    Directory of Open Access Journals (Sweden)

    Hisakazu Yano

    Full Text Available The prevalence of ESBL has been increasing worldwide. In this study, we investigated the molecular characteristics of ESBL among clinical isolates of Escherichia coli from a Japanese tertiary hospital. A total of 71 consecutive and nonduplicate clinical isolates of ESBL-positive E. coli collected at Tohoku University Hospital between January 2008 and March 2011 were studied. The antimicrobial susceptibility profile of these strains was determined. PCR and sequencing were performed to identify genes for β-lactamase (bla(TEM, bla(SHV, bla(OXA-1-like, and bla(CTX-M and plasmid-mediated quinolone resistance determinants (PMQR. The isolates were also analyzed by pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. Of the 71 strains, 68 were positive for CTX-M, 28 were positive for TEM, four were positive for OXA-1, and one was positive for SHV. Sequencing revealed that CTX-M-14 was the most prevalent (31/71, followed by CTX-M-27 (21/71 and then CTX-M-15 (9/71. Of the 28 TEM-positive strains, one was TEM-10 and the rest were TEM-1. One SHV-positive strain was SHV-12. The 21 CTX-M-27-producing isolates were divided into 14 unique PFGE types, while the 9 CTX-M-15 producers were divided into 8 types. Based on MLST, 9 CTX-M-14 procedures, 19 CTX-M-27 procedures, and 8 CTX-M-15 producers belonged to ST131. Thirty-five (94.6% of the 37 ST131 E. coli strains showed resistance to levofloxacin, which was a higher rate than among non-ST131 strains (63.6%. Among ESBL-producing isolates, one, two, and six possessed qnrB, qnrS, qepA, and aac(6'-Ib-cr, respectively. Of the 6 isolates with aac(6'-Ib-cr, 4 carried the CTX-M-15 gene. Our data suggest that CTX-M-15-producing E. coli ST131 has emerged as a worldwide pandemic clone, while CTX-M-27 (a variant of CTX-M-14 is also spreading among E. coli ST131 in Japan.

  12. CTX-M-14, CTX-M-24 and resistance in Escherichia coli and Klebsiella pneumoniae clinical isolates

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Extended-spectrum β-lactamases (ESBLs) are the main cause of resistance to the third and forth-generation cephalosporins in Enterobacteriaceae, which are mediated by plasmids and can hydrolyze oxyiminoaminothiazolyl cephalosporins and mono- bactams.1 Most of ESBLs are mutants of the classical TEM and SHV types, with one or more amino-acid substitution(s) in the active site. β-lactamase inhibitors, such as clavulanic acid, can inhibit their activities. Recently, The cefotaximases (CTX-M) group, a new family of plasmid-mediated ESBLs, reported from many countries increasingly, preferentially hydrolyzes cefotaxime.2 So far, CTX-M-3 has been the most prevalent type of ESBL in China and widespread in Enterobacteriaceae, while other CTX-M type ESBLs are few reported.3 In this study, we identified the CTX-M-14 and CTX-M-24 in Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli) clinical isolates from patients in Shanghai Huashan Hospital in 1999.

  13. Extended-spectrum β-lactamase (ESBL) in Danish clinical isolates of Escherichia coli and Klebsiella pneumoniae

    DEFF Research Database (Denmark)

    Hansen, Dennis Schrøder; Schumacher, Helga; Hansen, Frank;

    2012-01-01

    Most Gram-negative community-acquired and nosocomial infections are caused by Escherichia coli and Klebsiella pneumoniae, among which increasing resistance due to extended-spectrum β-lactamase (ESBL) is a major problem. We present data from the first Danish nationwide prevalence study on ESBL-pro......-producing E. coli, K. pneumoniae, and Proteus mirabilis in blood and urine cultures from hospitals and the community....

  14. Relationship between time to positivity of blood culture with clinical characteristics and hospital mortality in patients with Escherichia coli bacteremia

    Institute of Scientific and Technical Information of China (English)

    BO Shi-ning; BO Jian; NING Yong-zhong; ZHAO Yu; LU Xiao-lin; YANG Ji-yong; ZHU Xi; YAO Gai-qi

    2011-01-01

    Background Previous studies indicated that the time to positivity (TTP) of blood culture is a parameter correlating with degree of the bacteremia and outcome in patients with bloodstream infections caused by Escherichia coli (E.co/i). The objective of this study was to further investigate the diagnostic and prognostic power of using TTP to predict E. coli bacteremia.Methods A retrospective cohort study at two university hospitals was conducted. We retrieved all the medical records of those with E. coli bloodstream infection according to the records generated by their microbiology departments.Univariate and multivariate analyses were applied to identify clinical factors correlating with fast bacterial growth and significant prognostic factors for hospital mortality.Results Medical records of 353 episodes of E. coli bacteremia diagnosed between January 1,2007 and December 31,2009 were retrieved in the investigation. Univariate analysis demonstrated that the TTP≤7 hours group is associated with higher incidence of active malignancies (41.7% vs. 27.2%, P=0.010), neutropenia (30% vs.14.3%, P=0.007), primary bacteremia (55.0% vs. 33.4%, P=0.002), and poorer outcome (hospital mortality 43.3% vs.11.9%, P=0.000) than the TTP >7 hours group. Multivariate analysis revealed that the significant predictors of hospital mortality, in rank order from high to low, were TTP (for TTP <7 hours, odds ratio (OR): 4.886; 95% confidence interval (CI): 2.572-9.283; P=0.000),neutropenia (OR: 2.800; 95% CI:1.428-5.490; P=0.003), comedication of steroids or immunosuppressive agents (OR:2.670; 95% CI: 0.971-7.342; P=0.057).Conclusions Incidence of malignancies, neutropenia and primary bacterernia correlates with fast bacterial growth in patients with E. coli bacteremia. The parameter of TTP has been identified as a variable of highest correlation to hospital mortality and therefore can be potentially utilized as a mortality prognostic marker.

  15. Putative connection between zoonotic multiresistant extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in dog feces from a veterinary campus and clinical isolates from dogs

    OpenAIRE

    Schaufler, Katharina; Bethe, Astrid; Lübke-Becker, Antina; Ewers, Christa; Kohn, Barbara; Wieler, Lothar H; Günther, Sebastian

    2015-01-01

    Introduction: To contribute to the understanding of multiresistant bacteria, a ‘One Health’ approach in estimating the rate of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and getting insights into the transmission from clinical settings to the surrounding environment was employed by collecting fecal samples of dogs in a public area. Isolates were compared to those from samples of diseased dogs from a nearby small-animal clinic.Materials and methods: One hundred fecal sa...

  16. 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...... against the UPEC strain CFT073 was also studied. The different ABU strains displayed a wide variety of the measured characteristics. Half of the ABU strains displayed functional type 1 fimbriae while only one expressed functional P fimbriae. A good correlation between the growth rate of a particular...

  17. Expression of enterovirus 71 capsid protein VP1 in Escherichia coli and its clinical application

    Directory of Open Access Journals (Sweden)

    Mei Shi

    2013-12-01

    Full Text Available The VPl gene of enterovirus 71 (EV71 was synthesized, construct a recombinant plasmid pET15b/VP1 and expressed in E. coli BL21. The recombinant VP1 protein could specifically react with EV71-infected patient sera without the cross-reaction with serum antibodies of coxsackievirus A16 (CA16, A4, A5, B3 and B5 as well as echovirus 6. In acute and convalescent phases, IgM and IgG antibodies of 182 serum samples were detected by ELISA with recombinant VP1 protein as a coated antigen. The results showed that the sensitivity, specificity, positive predictive value (PPV and negative predictive value (NPV of IgM antibodies in serum samples for the diagnosis of EV71 infection were 90.1, 98.4, 98.8 and 88.7%, respectively; similarly, those of IgG antibodies in serum samples were 82.4, 89.1, 91.5 and 78.1%, respectively. Five of 80 samples (6.25% from CA16infected patients were detected positive by ELISA with recombinant VP1 protein in which indicated the cross reactions and 0 of 5 samples from patients infected with other enteroviruses including CA4, CA5, CB3, CB5 and echovirus 6. Therefore, the recombinant VP1 protein of EV7l may provide a theoretical reference for establishing an effective antibody screening of IgM for EV71-infected patients with clinically suspected hand, foot, and mouth disease (HFMD.

  18. Characterization of CTX-M ESBLs in Enterobacter cloacae, Escherichia coli and Klebsiella pneumoniae clinical isolates from Cairo, Egypt

    Directory of Open Access Journals (Sweden)

    Khalaf Noha G

    2009-06-01

    Full Text Available Abstract Background A high rate of resistance to 3rd generation cephalosporins among Enterobacteriaceae isolates from Egypt has been previously reported. This study aims to characterize the resistance mechanism (s to extended spectrum cephalosporins among resistant clinical isolates at a medical institute in Cairo, Egypt. Methods Nonconsecutive Klebsiella pneumoniae (Kp, Enterobacter cloacae (ENT and Escherichia coli (EC isolates were obtained from the clinical laboratory at the medical institute. Antibiotic susceptibility was tested by CLSI disk diffusion and ESBL confirmatory tests. MICs were determined using broth microdilution. Isoelectric focusing (IEF was used to determine the pI values, inhibitor profiles, and cefotaxime (CTX hydrolysis by the β-lactamases. PCR and sequencing were performed using blaCTX-M and ISEcp1-specific primers, with DNA obtained from the clinical isolates. Conjugation experiments were done to determine the mobility of blaCTX-M. Results All five clinical isolates were resistant to CTX, and were positive for ESBL screening. IEF revealed multiple β-lactamases produced by each isolate, including a β-lactamase with a pI of 8.0 in Kp and ENT and a β-lactamase with a pI of 9.0 in EC. Both β-lactamases were inhibited by clavulanic acid and hydrolyzed CTX. PCR and sequence analysis identified blaCTX-M-14 in Kp and ENT and a blaCTX-M-15 in EC. Both blaCTX-M-14 and blaCTX-M-15 were preceded by ISEcp1 elements as revealed by partial sequence analysis of the upstream region of the blaCTX-M genes. blaCTX-M-15 was transferable but not blaCTX-M-14. Conclusion This is the first report of CTX-M-14 in Kp and ENT isolates from Egypt, the Middle East and North Africa.

  19. Infection strategies of enteric pathogenic Escherichia coli

    OpenAIRE

    Clements, Abigail; Young, Joanna C.; Constantinou, Nicholas; Frankel, Gad

    2012-01-01

    Enteric Escherichia coli (E. coli) are both natural flora of humans and important pathogens causing significant morbidity and mortality worldwide. Traditionally enteric E. coli have been divided into 6 pathotypes, with further pathotypes often proposed. In this review we suggest expansion of the enteric E. coli into 8 pathotypes to include the emerging pathotypes of adherent invasive E. coli (AIEC) and Shiga-toxin producing enteroaggregative E. coli (STEAEC). The molecular mechanisms that all...

  20. Comparative Analysis of Quinolone Resistance in Clinical Isolates of Klebsiella pneumoniae and Escherichia coli from Chinese Children and Adults

    Directory of Open Access Journals (Sweden)

    Ying Huang

    2015-01-01

    Full Text Available The objective of this study was to compare quinolone resistance and gyrA mutations in clinical isolates of Klebsiella pneumoniae and Escherichia coli from Chinese adults who used quinolone in the preceding month and children without any known history of quinolone administration. The antimicrobial susceptibilities of 61 isolates from children and 79 isolates from adults were determined. The mutations in the quinolone resistance-determining regions in gyrA gene were detected by PCR and DNA sequencing. Fluoroquinolone resistance and types of gyrA mutations in isolates from children and adults were compared and statistically analyzed. No significant differences were detected in the resistance rates of ciprofloxacin and levofloxacin between children and adults among isolates of the two species (all P>0.05. The double mutation Ser83→Leu + Asp87→Asn in the ciprofloxacin-resistant isolates occurred in 73.7% isolates from the children and 67.9% from the adults, respectively (P=0.5444. Children with no known history of quinolone administration were found to carry fluoroquinolone-resistant Enterobacteriaceae isolates. The occurrence of ciprofloxacin resistance and the major types of gyrA mutations in the isolates from the children were similar to those from adults. The results indicate that precautions should be taken on environmental issues resulting from widespread transmission of quinolone resistance.

  1. Variable tellurite resistance profiles of clinically-relevant Shiga toxin-producing Escherichia coli (STEC) influence their recovery from foodstuffs.

    Science.gov (United States)

    Kerangart, Stéphane; Douëllou, Thomas; Delannoy, Sabine; Fach, Patrick; Beutin, Lothar; Sergentet-Thévenot, Delphine; Cournoyer, Benoit; Loukiadis, Estelle

    2016-10-01

    Tellurite (Tel)-amended selective media and resistance (Tel-R) are widely used for detecting Shiga toxin-producing Escherichia coli (STEC) from foodstuffs. Tel-R of 81 O157 and non-O157 STEC strains isolated from animal, food and human was thus investigated. Variations of STEC tellurite minimal inhibitory concentration (MIC) values have been observed and suggest a multifactorial and variable tellurite resistome between strains. Some clinically-relevant STEC were found highly susceptible and could not be recovered using a tellurite-based detection scheme. The ter operon was highly prevalent among highly Tel-R STEC but was not always detected among intermediately-resistant strains. Many STEC serogroup strains were found to harbor sublines showing a gradient of MIC values. These Tel-R sublines showed statistically significant log negative correlations with increasing tellurite concentration. Whatever the tellurite concentration, the highest number of resistant sublines was observed for STEC belonging to the O26 serogroup. Variations in the number of these Tel-R sublines could explain the poor recovery of some STEC serogroups on tellurite-amended media especially from food products with low levels of contamination. Comparison of tellurite MIC values and distribution of virulence-related genes showed Tel-R and virulence to be related. PMID:27375242

  2. TEM-4, a new plasmid-mediated beta-lactamase that hydrolyzes broad-spectrum cephalosporins in a clinical isolate of Escherichia coli.

    OpenAIRE

    Paul, G C; Gerbaud, G; Bure, A; Philippon, A M; B. Pangon; Courvalin, P.

    1989-01-01

    A clinical isolate of Escherichia coli, strain CB-134, recovered in 1986 from an abdominal abscess, exhibited resistance to penams, oxyimino-beta-lactams including broad-spectrum cephalosporins (cefotaxime, ceftriaxone, ceftazidime), and aztreonam but remained susceptible to cephamycins (cefoxitin, cefotetan) and to moxalactam and imipenem. Clavulanate (2 micrograms/ml) restored the susceptibility of the strain to broad-spectrum cephalosporins and aztreonam. A beta-lactamase with an isoelectr...

  3. Emergence of clinical isolates of Escherichia coli producing TEM-1 derivatives or an OXA-1 beta-lactamase conferring resistance to beta-lactamase inhibitors.

    OpenAIRE

    Zhou, X. Y.; Bordon, F; Sirot, D; Kitzis, M D; Gutmann, L

    1994-01-01

    Sixteen Escherichia coli clinical isolates which were resistant to ampicillin and amoxicillin-clavulanate but susceptible to cephalothin were studied. Eight strains showed the presence of a beta-lactamase which comigrates with reference OXA-1 enzyme. The eight other strains produced different TEM-1 derivatives which had in common a higher Km for penicillins and a higher 50% inhibitory concentration for the beta-lactamase inhibitors. By oligotyping and sequencing of PCR products, it was shown ...

  4. Prevalence and molecular characterization of clinical isolates of Escherichia coli expressing an AmpC phenotype

    DEFF Research Database (Denmark)

    Jørgensen, Rikke Lind; Nielsen, Jesper Boye; Friis-Møller, Alice;

    2010-01-01

    . Hyperproduction of AmpC beta-lactamase was confirmed by isoelectric focusing (IEF). The presence of a plasmid-mediated ampC gene (pAmpC) was detected by multiplex PCR. The promoter and the entire reading frame of the chromosomal ampC gene were sequenced to identify promoter mutations associated...... by multilocus sequence typing (MLST). The remaining isolates all had mutations or insertions in the promoter region, which could explain increased expression of the chromosomal AmpC enzyme. Mutations in the ampC gene associated with extended activity were rare and did not cause resistance to cefepime....... Sequencing of ampC showed that most isolates were not clonally related. CONCLUSIONS: E. coli expressing an AmpC phenotype occur sporadically and cause significant resistance to cephalosporins. The majority of these are hyperproducing chromosomal ampC although some isolates have acquired pAmpC....

  5. Evaluation of phenotypic tests for detection of Klebsiella pneumoniae carbapenemase and metallo-beta-lactamase in clinical isolates of Escherichia coli and Klebsiella species

    Directory of Open Access Journals (Sweden)

    Kalpana Chauhan

    2015-01-01

    Full Text Available Context: Carbapenemase production is an important mechanism responsible for carbapenem resistance. Aims: Phenotypic detection and differentiation of types of carbapenemase in carbapenem resistant Enterobacteriaceae is important for proper infection control and appropriate patient management. Settings and Design: We planned a study to determine the occurrence of Class A Klebsiella pneumoniae carbapenemase (KPC type and Class B Metallo-β-lactamase (MBL type carbapenemase in hospital and community. Materials and Methods: Clinical isolates of Escherichia coli and Klebsiella species and simultaneously evaluate different phenotypic methods for detection of carbapenemases. Results: It was observed that 20.72% clinical isolates of E. coli and Klebsiella spp. were resistant to carbapenem on screening of which, 14.64% were E. coli and 29.69% were Klebsiella spp. Using phenotypic confirmatory tests the occurrence of carbapenemase production was found to be 87.01% in E. coli and 91.51% in Klebsiella spp. using both modified Hodge test (MHT and combined disk test (CDT using imipenem-ethylenediaminetetraacetic acid. Conclusions: Both MBL and KPC type carbapenemases were seen among clinical isolates of E. coli and Klebsiella spp. CDT is simple, rapid and technically less demanding procedure, which can be used in all clinical laboratories. Supplementing MHT with CDT is reliable phenotypic tests to identify the class A and class B carbapenemase producers.

  6. OBSERVATIONS ON CLINICAL TREATMENT TRIALS OF INDUCED ESCHERICHIA COLI DIARRHOEA IN BUFFALO NEONATAL CALVES

    Directory of Open Access Journals (Sweden)

    M. T. Javed, A. Khan, Abid Hussain and Babar Niaz

    2000-01-01

    Full Text Available The study was conducted on 24 calves of one week-age, randomly divided into four groups, of six calves each. First three groups were experimentally infected with E. coli and given treatment in various combinations, while group four was taken as uninfected untreated control. Results obtained on different parameters were, green to yellow-white diarrhoea with variable consistency from watery to semisolid. Generally in all groups during first two days, calves passed faeces around 6-10 times a day and this frequency lowered in about 2-4 days. During first 3-4 days of treatment, all calves appeared weak, dull, depressed with cold skin and wetness of the muzzle, while oral mucosa was pale and eyes were sunken. Overall mean respiration rate of treatment groups was slower (P<0.05 than control group. However, pulse rate showed no difference between treatment and control group. Overall mean rectal temperature was lower (P<0.05 in calves treated with antibiotic alone and with antibiotic + electrolytes, while body weight was higher (P<0.05 in calves treated with antibiotic but was lower along with creatinine (P<0.05 in calves treated with antibiotic + electrolytes and those treated with electrolytes alone.

  7. Phylogeny, clinical associations, and diagnostic utility of the pilin subunit gene (sfpA) of sorbitol-fermenting, enterohemorrhagic Escherichia coli O157:H-

    NARCIS (Netherlands)

    Friedrich, Alexander W; Nierhoff, Katja V; Bielaszewska, Martina; Mellmann, Alexander; Karch, Helge

    2004-01-01

    The plasmid-borne sfpA gene encodes the pilin subunit in sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157:H-. We investigated the distribution of sfpA among 600 E. coli isolates comprising the complete E. coli standard reference (ECOR) and diarrheagenic E. coli (DEC) strain co

  8. Draft Genome Sequence of Uropathogenic Escherichia coli Strain NB8.

    Science.gov (United States)

    Weng, Xing-Bei; Mi, Zu-Huang; Wang, Chun-Xin; Zhu, Jian-Ming

    2016-01-01

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

  9. Interaction of Big Celandine Extract and Plasmid DNA, Excreted From the Clinical Strain Escherichia Coli

    Directory of Open Access Journals (Sweden)

    E.G. Chebotarjova

    2009-09-01

    Full Text Available Search for compounds which possess antibacterial activity and have an effect on plasmid DNA, is one more of the important problems of applied medicine. Natural substances are the most desirable candidates for this role. Plasmid DNA excretion was carried out from the strain Echerihiacoli, derived from patient N., who suffered from chronic pyelonephritis, in the bacteriological laboratory of the Regional clinical hospital of Saratov according to the modified method Birnboim and Doli. The calculation of alkaloid concentration was made, e.g. Sanguinarin and Cheler-etrin contained in celandine extract. The devised method has been tested on five celandine tincture samples, stored for the research of the stability of the content of alkaloids and other quality factors of the given preparation. In so doing the content of the alkaloid sum in tincture changes within the limits of 1 %. Abatement of plasmid DNA concentration after the cell treatment by celandine extract is revealed.

  10. Experimental and Clinical Studies on Fluoroquinolone-insusceptible Escherichia coli Isolated from Patients with Urinary Tract Infections from 1994 to 2007

    Directory of Open Access Journals (Sweden)

    Watanabe,Toyohiko

    2009-10-01

    Full Text Available Urinary tract infections (UTIs due to fluoroquinolone-insusceptible Escherichia coli have become increasingly common in recent years. We investigated the potential relationships between clinical measures to combat fluoroquinolone-insusceptible E. coli and experimental analyses on E. coli isolates. Over a 14-year period from 1994 through 2007, a total of 828 E. coli isolates were collected from patients (one isolate per patient with UTI at the urology ward of Okayama University Hospital. We analyzed the mutations in quinolone resistance-determining regions of DNA gyrase (gyrA and topoisomerase IV (parC. The production of biofilm by these isolates was also examined and the associated medical records were retrospectively reviewed. Seven of 189 (3.7% strains from uncomplicated UTIs and 82 of 639 (12.8% strains from complicated UTIs were insusceptible to fluoroquinolones. Amino acid replacements of type II topoisomerases were frequently observed at positions 83 and 87 in GyrA and at positions 80 and 84 in ParC. No significant difference in the biofilm-forming capabilities was observed between fluoroquinolone-susceptible and -insusceptible E. coli. Our study suggests that biofilm formation of fluoroquinolone-insusceptible E. coli isolates is not a major mechanism of resistance in patients with UTI.

  11. Preparation of ciprofloxacin-coated zinc oxide nanoparticles and their antibacterial effects against clinical isolates of Staphylococcus aureus and Escherichia coli

    DEFF Research Database (Denmark)

    Seif, Sepideh; Kazempour, Zarah Bahri; Pourmand, Mohammad Reza;

    2011-01-01

    carbonyl group in ciprofloxacin is actively involved in forming chemical - rather than physical - bonds with zinc oxide nanoparticles. Also the antibacterial activity of free zinc oxide nanoparticles and ciprofloxacin-coated zinc oxide nanoparticles have been evaluated against different clinical isolates...... pure ciprofloxacin) considerably enhanced the antibacterial activity of zinc oxide nanoparticles against different isolates of Staphylococcus aureus and Escherichia coli (4 to 32 fold increase). The result is of particular value, since it demonstrates that, by using biocompatible zinc oxide...... nanoparticles in combination therapy, lower amounts of antibiotics may be needed...

  12. High Prevalence of Escherichia coli-Producing CTX-M-15 Extended-Spectrum Beta-Lactamases in Poultry and Human Clinical Isolates in Romania.

    Science.gov (United States)

    Maciuca, Iuliana E; Williams, Nicola J; Tuchilus, Cristina; Dorneanu, Olivia; Guguianu, Eleonora; Carp-Carare, Catalin; Rimbu, Cristina; Timofte, Dorina

    2015-12-01

    Use of antibiotics in food animals may contribute to development and spread of resistant organisms, particularly so in some countries. The aim of this study was two-fold; first, to establish the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in chicken production in a region within Romania. Second, to study the relatedness of ESBL-producing E. coli isolates recovered from broilers, abattoir workers where the chickens were slaughtered and from the human clinical specimens from two regional hospitals. The results indicated a very high (69%) rate of carriage of ESBL and AmpC-producing E. coli in chickens with 36% CTX-M producers. Sequencing showed that chickens in Romania have the highest worldwide prevalence (53%) of blaCTX-M-15 reported in poultry E. coli isolates. The majority (53%) of the extended-spectrum cephalosporin-resistant E. coli carried plasmid-mediated blaampC genes, mostly blaCMY-2 type, one of the highest prevalences reported in Europe. The predominant CTX-M type found in the human clinical E. coli isolates was blaCTX-M-15 and most isolates coharbored blaOXA-1, blaTEM, and aac(6')-ib-cr. The majority (60%) of the human clinical isolates belonged to the pandemic virulent clone B2-ST131. The clonal relationship between broiler and the human CTX-M-producing E. coli isolates was assessed by macrorestriction pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), which indicated strain diversity with no common STs found between human and poultry isolates. Moreover, IncI1 was the most prevalent replicon found in broiler ESBL-producing E. coli isolates and also in transconjugants, indicating that plasmids and not clonal spread may play a role in the transfer of blaCTX-M genes. This study identifies a high prevalence of ESBL-producing E. coli from broiler chickens in Romania with a high occurrence incidence of blaCTX-M-15, which reflects the main ESBL type found in human E. coli infections in this

  13. Thiol-sensitive promoters of Escherichia coli.

    OpenAIRE

    Javor, G T; Stringer, C D; Ryu, J.

    1988-01-01

    Mu dX(lac) insertion mutants of Escherichia coli CSH50 in which the expression of the lacZ gene was sensitive to the presence of exogenous 1-thioglycerol or dithiothreitol were isolated. Both stimulatory and inhibitory mutants were found. The existence of several thiol-sensitive promoters suggests that exogenous thiols may provoke global stress responses in E. coli.

  14. 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...

  15. Fimbrial adhesins from extraintestinal Escherichia coli

    DEFF Research Database (Denmark)

    Klemm, Per; Hancock, Viktoria; Schembri, Mark A.

    2010-01-01

    Extraintestinal pathogenic Escherichia coli (ExPEC) represent an important subclass of E. coli that cause a wide spectrum of diseases in human and animal hosts. Fimbriae are key virulence factors of ExPEC strains. These long surface located rod-shaped organelles mediate receptor-specific attachment...

  16. Global gene expression in Escherichia coli biofilms

    DEFF Research Database (Denmark)

    Schembri, Mark; Kjærgaard, K.; Klemm, Per

    2003-01-01

    antimicrobial treatments and host immune defence responses. Escherichia coli has been used as a model organism to study the mechanisms of growth within adhered communities. In this study, we use DNA microarray technology to examine the global gene expression profile of E. coli during sessile growth compared...

  17. 99mTechnetium labelled Escherichia coli

    International Nuclear Information System (INIS)

    Samples of a culture of unlabeled Escherichia coli were incubated with different concentrations of stannous chloride for various time periods. 99mTc (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 99mTc-E. coli and E. coli did not show any statistical differences, these results demonstrate that labelling of E. coli with 99mTc does not modify the bacterial viability, and the radiolabelled bacteria may be a good model to study bacterial translocation

  18. 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...... dissemination of resistant E.coli has in particular been driven by the spread of a few specific E.coli-lineages and it seems that there is a difference between the sequence types found among resistant E.coli, ESBL-producing E.coli and antibiotic susceptible E.coli. The overall objectives of this thesis were to...

  19. Mutant prevention concentration and phenotypic and molecular basis of fluoroquinolone resistance in clinical isolates and in vitro-selected mutants of Escherichia coli from dogs.

    Science.gov (United States)

    Gebru, Elias; Damte, Dereje; Choi, Myung-Jin; Lee, Seung-Jin; Kim, Young-Hoan; Park, Seung Chun

    2012-01-27

    The antibacterial activity, selection of Escherichia coli (E. coli) mutants and mechanisms of fluoroquinolone resistance were investigated by integrating the minimum inhibitory concentration (MIC), mutant prevention concentration (MPC) and in vitro dynamic model approaches. Difloxacin and orbifloxacin, for which the above information has been scarce, were used. A range of area under curve over a 24h interval (AUC(24h))/MIC ratios and selected E. coli strains were investigated using the dynamic models. Continuous incubation for three days in the presence of difloxacin or orbifloxacin resulted in losses in E. coli susceptibility. An AUC(24h)/MIC (AUC(24h)/MPC)-dependent fluoroquinolone activity and selection of E. coli mutants was confirmed. Maximum losses in susceptibility occurred at AUC(24h)/MIC ratios of 54 (orbifloxacin) and 57.3 (difloxacin). AUC(24h)/MIC ratios of 169.8 (orbifloxacin) and 199.5 (difloxacin) were estimated to be protective against the selection of E. coli mutants, and the corresponding ratios based on AUC(24h)/MPC predictions were 34 (orbifloxacin) and 36.3 (difloxacin). When integrating our in vitro data with pharmacokinetic data in dogs, the conventional clinical doses of both drugs were found to be inadequate to attain the above protective values for 90% of the mutant subpopulation (AUC(24h)/MPC(90)). Both target mutations, esp. at codon 83 (Ser to Leu) of gyrA, and overexpression of efflux pumps contributed to resistance development, with mutants also showing decreased susceptibility to enrofloxacin and marbofloxacin. Additional studies would determine the role of mutations found outside the QRDR, at codon 24 of gyrA, and at codon 116 of parC, and establish the significance of these observations in vivo. PMID:21893387

  20. Use of a MAMA-PCR Method to detect gyrA Mutations in Nalidixic Acid-Resistant Clinical Isolates of Escherichia coli

    Directory of Open Access Journals (Sweden)

    A Karami

    2008-05-01

    Full Text Available Background: Enterobacteriaceae are a large group of bacteria widely distributed in nature. Escherichia coli is the most com­mon cause of urinary tract infection. Two amino acid substitutions, in GyrA, are commonly responsible for quinolone re­sistance in E. coli. The aim of this study was molecular survey of nalidixic acid resistance E.coli isolated from patients in the codones of 83 and 87 gyrA genes.Methods: During 5 months (January to June 2005 of Molecular Survey of Nalidixic Acid Resistance, one hundred and twenty-one E. coli isolates from urine samples of patients referred to clinical laboratory of Baqiyatallah Hospital were cul­tured. Differential tests were done for diagnosis of E.coli. An economical and time-efficient mismatch amplification muta­tion assay (MAMA PCR was developed to detect mutations in the chromosomal gyrA gene causing these substitutions.Results: In nalidixic acid antibiogram test, 55 cases (45.5% were sensitive, 63 cases (52% were resistant and 3 cases (2.5% were intermediate. Results of PCR and MIC were similar to antibiogram. There was not any mutation in the sensi­tive samples but there were performed five mutations on the 85, 81, 107, 97 and 87 codones of resistance samples. The codone number 87s mutation is one of the main mutations of nalidixic acid resistance.Conclusion: Depending on results of this study and comparison with other studies, trend of resistance of E.coli is increas­ing. Therefore, we recommend control of antibiotic misusage and application of MIC and PCR tests (if possible prior to treat­ment for suitable selection of antibiotic and prevention of microbial resistance.

  1. 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...

  2. Antibiotic Resistance to Third Generation Cephalosporins Due to CTX-M-Type Extended-Spectrum β-Lactamases in Clinical Isolates of Escherichia coli

    Directory of Open Access Journals (Sweden)

    M Mirzaee

    2009-03-01

    Full Text Available "nBackground: Organisms producing CTX-M-β-lactamase are emerging around the world as a source of resistance to oxyiminocephalosporins such as cefotaxime. However, the laboratory detection of these strains is not well defined. The aim of this study was to determine the presence and prevalence of known CTX-M-β-lactamases genes in clinical isolates of  Escherichia coli from hospitals of Tehran."nMethods: During six months (September to February, 2006, 160 clinical isolates of Escherichia coli collected from three university hospitals of Tehran.  Phenotypic screening and confirmation tests for ESBL detection was according to CLSI advised. All of the ESBL-producing isolates were examined by PCR for presence of bla CTX-M genes."nResults: Primary phenptypic tests revealed that %56.69 (n=89 of E. coli isolates produced ESBLs. In confirmatory tests by use of clavulanic acid, ESBL production were confirmed (P+C+ in %96.7 (n=86 of isolates with primary positive test. The presence of an ESBL was not confirmed (P+C- in 3.3% (n=3 of the screen positive. Of all screen positive isolates, 34 (35.78% were positive for bla CTX-M genes from the CTX-M-I group, indicating CTX-M-1-like β-lactamases and Two (2.1% were positive for bla CTX-M genes from the CTX-M-III group, indicating CTX-M-3-like β-lactamases. The remainder 59 (62.2% were negative for bla CTX-M genes."nConclusions: The levels of resistance to ceftazidim were remarkably varible among CTX-M producers. This study provides futher evidence of the global dissemination of  CTX-M type ESBLs and emphasize the need for their epidemiological monitoring.

  3. Clinical trial: probiotic treatment of acute distal ulcerative colitis with rectally administered Escherichia coli Nissle 1917 (EcN)

    OpenAIRE

    Matthes Harald; Krummenerl Thomas; Giensch Manfred; Wolff Corinna; Schulze Jürgen

    2010-01-01

    Abstract Background Probiotics are effective in inflammatory bowel diseases. Clinical effectiveness and dose dependency of E. coli Nissle (EcN) enemas were investigated in ulcerative colitis (UC). Methods In a double-blind study, 90 patients with moderate distal activity in UC were randomly assigned to treatment with either 40, 20, or 10 ml enemas (N = 24, 23, 23) containing 10E8 EcN/ml or placebo (N = 20). The study medication was taken once daily for at least 2 weeks. After 2, 4 and/or 8 we...

  4. Control of Ribosome Synthesis in Escherichia coli

    DEFF Research Database (Denmark)

    Molin, Søren; Meyenburg, K. von; Måløe, O.;

    1977-01-01

    The rate of ribosome synthesis and accumulation in Escherichia coli during the transition after an energy source shift-down was analyzed. The shift was imposed on cultures of stringent and relaxed strains growing in glucose minimal medium by the addition of the glucose analogue {alpha}-methylgluc......The rate of ribosome synthesis and accumulation in Escherichia coli during the transition after an energy source shift-down was analyzed. The shift was imposed on cultures of stringent and relaxed strains growing in glucose minimal medium by the addition of the glucose analogue {alpha...

  5. Hydrogen production by recombinant Escherichia coli strains

    OpenAIRE

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

    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 increas...

  6. Native valve Escherichia coli endocarditis following urosepsis

    OpenAIRE

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

    2013-01-01

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

  7. Beta-alanine synthesis in Escherichia coli.

    OpenAIRE

    Cronan, J. E.

    1980-01-01

    The enzyme, aspartate 1-decarboxylase (L-aspartate 1-carboxy-lyase; EC 4.1.1.15), that catalyzes the reaction aspartate leads to beta-alanine + CO2 was found in extracts of Escherichia coli. panD mutants of E. coli are defective in beta-alanine biosynthesis and lack aspartate 1-decarboxylase. Therefore, the enzyme functions in the biosynthesis of the beta-alanine moiety of pantothenate. The genetic lesion in these mutants is closely linked to the other pantothenate (pan) loci of E. coli K-12.

  8. 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...... the pan-genome and about 80% of a typical genome; some of these variable genes tend to be co-localized on genomic islands. The diversity within the species E. coli, and the overlap in gene content between this and related species, suggests a continuum rather than sharp species borders in this group of...

  9. Cellular chain formation in Escherichia coli biofilms

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; Klemm, Per

    2009-01-01

    In this study we report on a novel structural phenotype in Escherichia coli biofilms: cellular chain formation. Biofilm chaining in E. coli K-12 was found to occur primarily by clonal expansion, but was not due to filamentous growth. Rather, chain formation was the result of intercellular......; type I fimbriae expression significantly reduced cellular chain formation, presumably by steric hindrance. Cellular chain formation did not appear to be specific to E coli K-12. Although many urinary tract infection (UTI) isolates were found to form rather homogeneous, flat biofilms, three isolates...

  10. Deuterium incorporation into Escherichia-coli proteins

    DEFF Research Database (Denmark)

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

    1986-01-01

    -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...

  11. Inhibitory effect of pomegranate (Punica granatum L.) polyphenol extracts on the bacterial growth and survival of clinical isolates of pathogenic Staphylococcus aureus and Escherichia coli.

    Science.gov (United States)

    Pagliarulo, Caterina; De Vito, Valentina; Picariello, Gianluca; Colicchio, Roberta; Pastore, Gabiria; Salvatore, Paola; Volpe, Maria Grazia

    2016-01-01

    In the present study major polyphenols of pomegranate arils and peel by-products were extracted in 50% (v/v) aqueous ethanol, characterized and used in microbiological assays in order to test antimicrobial activity against clinically isolated human pathogenic microorganisms. Total concentration of polyphenols and in vitro antioxidant properties were determined by the Folin-Ciocalteu and DPPH methods, respectively. The most abundant bioactive molecules, including anthocyanins, catechins, tannins, gallic and ellagic acids were identified by RP-HPLC-DAD, also coupled to off-line matrix assisted laser desorption/ionization (MALDI-TOF) mass spectrometry (MS). The inhibitory spectrum of extracts against test microorganisms was assessed by the agar well-diffusion method. Data herein indicated that both pomegranate aril and peel extracts have an effective antimicrobial activity, as evidenced by the inhibitory effect on the bacterial growth of two important human pathogens, including Staphylococcus aureus and Escherichia coli, which are often involved in foodborne illness. PMID:26213044

  12. Clinical trial: probiotic treatment of acute distal ulcerative colitis with rectally administered Escherichia coli Nissle 1917 (EcN

    Directory of Open Access Journals (Sweden)

    Matthes Harald

    2010-04-01

    Full Text Available Abstract Background Probiotics are effective in inflammatory bowel diseases. Clinical effectiveness and dose dependency of E. coli Nissle (EcN enemas were investigated in ulcerative colitis (UC. Methods In a double-blind study, 90 patients with moderate distal activity in UC were randomly assigned to treatment with either 40, 20, or 10 ml enemas (N = 24, 23, 23 containing 10E8 EcN/ml or placebo (N = 20. The study medication was taken once daily for at least 2 weeks. After 2, 4 and/or 8 weeks the clinical DAI was assessed together with tolerance to treatment. Patients who reached clinical DAI ≤ 2 within that time were regarded as responders. Results According to ITT analysis the number of responders was not significantly higher in the EcN group than in the placebo group (p = 0.4430, 2-sided. However, the Jonckheere-Terpstra rank correlation for dose-dependent efficacy indicated a significant correlation of per-protocol responder rates (p = 0.0446, 2-sided. Time to remission was shortest with EcN 40 ml, followed by EcN 20 ml. The number of adverse events did not differ notably. Conclusion In contrast to ITT analysis, efficacy of rectal EcN application was significant in PP and points to EcN as a well tolerated treatment alternative in moderate distal UC. Trial registration German Clinical Trials Register DRK00000234.

  13. Control of Ribosome Synthesis in Escherichia coli

    DEFF Research Database (Denmark)

    Molin, Søren; Meyenburg, K. von; Måløe, O.; Trier Hansen, M.; Pato, M. L.

    1977-01-01

    The rate of ribosome synthesis and accumulation in Escherichia coli during the transition after an energy source shift-down was analyzed. The shift was imposed on cultures of stringent and relaxed strains growing in glucose minimal medium by the addition of the glucose analogue {alpha...

  14. Escherichia Coli--Key to Modern Genetics.

    Science.gov (United States)

    Bregegere, Francois

    1982-01-01

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

  15. Detection of O antigens in Escherichia coli

    Science.gov (United States)

    Lipopolysaccharide on the surface of Escherichia coli constitute the O antigens, which are important virulence factors that are targets of both the innate and adaptive immune system and play a major role in host-pathogen interactions. O antigens that are responsible for antigenic specificity of the ...

  16. Progressive segregation of the Escherichia coli chromosome

    DEFF Research Database (Denmark)

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

    2006-01-01

    We have followed the fate of 14 different loci around the Escherichia coli chromosome in living cells at slow growth rate using a highly efficient labelling system and automated measurements. Loci are segregated as they are replicated, but with a marked delay. Most markers segregate in a smooth...

  17. The eclipse period of Escherichia coli

    DEFF Research Database (Denmark)

    von Freiesleben, Ulrik; Krekling, Martin A.; Hansen, Flemming G.;

    2000-01-01

    The minimal time between successive initiations on the same origin (the eclipse) in Escherichia coli was determined to be approximately 25-30 min. An inverse relationship was found between the length of the eclipse and the amount of Dam methyltransferase in the cell, indicating that the eclipse...

  18. 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....

  19. Vibrio parahaemolyticus, enterotoxigenic Escherichia coli, enterohemorrhagic Escherichia coli and Vibrio cholerae

    OpenAIRE

    Takeda, Yoshifumi

    2011-01-01

    This review highlighted the following: (i) pathogenic mechanism of the thermostable direct hemolysin produced by Vibrio parahaemolyticus, especially on its cardiotoxicity, (ii) heat-labile and heat-stable enterotoxins produced by enterotoxigenic Escherichia coli, especially structure–activity relationship of heat-stable enterotoxin, (iii) RNA N-glycosidase activity of Vero toxins (VT1 and VT2) produced by enterohemorrhagic Escherichia coli O157:H7, (iv) discovery of Vibrio cholerae O139, (v) ...

  20. Pathogenomics of uropathogenic Escherichia coli

    OpenAIRE

    Agarwal, J.; Srivastava, S.; Singh, M.

    2012-01-01

    Subset of faecal E. coli that can enter, colonize urinary tract and cause infection are known as uropathogenic E. coli (UPEC). UPEC strains act as opportunistic intracellular pathogens taking advantage of host susceptibility using a diverse array of virulence factors. Presence of specific virulence associated genes on genomic/pathogenicity islands and involvement of horizontal gene transfer appears to account for evolution and diversity of UPEC. Recent success in large-scale genome sequencing...

  1. Synergistic effects in mixed Escherichia coli biofilms

    DEFF Research Database (Denmark)

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

    2006-01-01

    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 the strongest effects was most often linked to conjugative transmission of natural plasmids carried by the E. coli isolates (70%). Thus, the capacity of an isolate to promote the biofilm through cocultivation was (i) transferable to the K-12 strain, (ii) was linked with the acquisition...

  2. Intramacrophage survival of uropathogenic Escherichia coli: Differences between diverse clinical isolates and between mouse and human macrophages

    DEFF Research Database (Denmark)

    Bokil, Nilesh J.; Totsika, Makrina; Carey, Alison J.; Stacey, Katryn J.; Hancock, Viktoria; Saunders, Bernadette M.; Ravasi, Timothy; Ulett, Glen C.; Schembri, Mark A.; Sweet, Matthew J.

    2011-01-01

    Uropathogenic E. coli (UPEC) are the primary cause of urinary tract infections. Recent studies have demonstrated that UPEC can invade and replicate within epithelial cells, suggesting that this bacterial pathogen may occupy an intracellular niche within the host. Given that many intracellular...... pathogens target macrophages, we assessed the interactions between UPEC and macrophages. Colonization of the mouse bladder by UPEC strain CFT073 resulted in increased expression of myeloid-restricted genes, consistent with the recruitment of inflammatory macrophages to the site of infection. In in vitro...... assays, CFT073 was able to survive within primary mouse bone marrow-derived macrophages (BMM) up to 24h post-infection. Three additional well-characterized clinical UPEC isolates associated with distinct UTI symptomatologies displayed variable long-term survival within BMM. UPEC strains UTI89 and VR50...

  3. Spurious hydrogen sulfide production by Providencia and Escherichia coli species.

    OpenAIRE

    Treleaven, B E; Diallo, A. A.; Renshaw, E C

    1980-01-01

    Hydrogen sulfide production was noted in two Escherichia coli strands and one Provaidenica alcalifaciens (Proteus inconstans A) strain isolated from clinical stool specimens durin the summer of 1979. An investigation into this phenomenon revealed the predence of Eubacterium lentum, an anaerobe, growing in synergism with the Enterobacteriaceae and producing H2s. The implications of this association are discssed with reference to clinical microbiology laboratory practice.

  4. Molecular Characterization of Diarrheagenic Escherichia coli from Libya

    OpenAIRE

    Ali, Mostafa Mohamed M; Mohamed, Zienat Kamel; Klena, John D.; Ahmed, Salwa Fouad; Tarek A.A. Moussa; Ghenghesh, Khalifa Sifaw

    2012-01-01

    Diarrheagenic Escherichia coli (DEC) are important enteric pathogens that cause a wide variety of gastrointestinal diseases, particularly in children. Escherichia coli isolates cultured from 243 diarrheal stool samples obtained from Libyan children and 50 water samples were screened by polymerase chain reaction (PCR) for genes characteristic of enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohemorrhagic E. coli (EHEC), and enteroinvasiv...

  5. Molecular characterization and clinical significance of New Delhi metallo-beta-lactamases-1 producing Escherichia coli recovered from a South Indian tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Arindam Ckakraborty

    2015-01-01

    Full Text Available Context: The increased rate of infection by New Delhi metallo-beta-lactamases-1 (NDM1 producing Escherichia coli is a major concern since they show a high rate of drug resistance and are responsible for mortality and morbidity. Aims: To characterize the NDM1 producing E. coli isolates and their impact on patients′ clinical outcome. Settings and Design: This descriptive study was carried out in a multi-specialty tertiary care hospital. Materials and Methods: Three hundred nonrepeat strains of E. coli from inpatients were included in the study. Modified Hodge test and metallo-beta-lactamases (MBL e-test were performed to detect carbapenemase and MBL activity. Polymerase chain reaction (PCR technique was performed to detect NDM1. NDM1 positive isolates were further tested for plasmid mediated AmpC, blaCTX , blaSHV , blaTEM genes and also for phylogrouping by PCR methods. Treatment and patients′ clinical outcome were also analyzed. Results: Out of 300 isolates, 21 (7% were MBL producers by phenotypic methods. Of this, 17 (81% were NDM1 positives, among the NDM1 producers 6 (35% isolates were belongs to phylogroups D followed by A 5 (29%, B1 4 (24% and B2 2 (12%, 15 (88% isolates were blaCTX-M positive suggestive of extended-spectrum beta lactamase producing strain and 7 (47% were positive with CIT type of AmpC. With the follow-up of the patients, it was found that 12 (71% recovered and 3 (18% developed relapses, and mortality was seen in 2 (12% patients. Conclusions: NDM1 producing isolates showed a high degree of drug resistance but can be treated with suitable antimicrobials, in the majority. Early detection and choice of appropriate antibiotics may help in reducing mortality and morbidity.

  6. Variation in resistance traits, phylogenetic backgrounds, and virulence genotypes among Escherichia coli clinical isolates from adjacent hospital campuses serving distinct patient populations.

    Science.gov (United States)

    Drawz, Sarah M; Porter, Stephen; Kuskowski, Michael A; Johnston, Brian; Clabots, Connie; Kline, Susan; Ferrieri, Patricia; Johnson, James R

    2015-09-01

    Escherichia coli sequence type 13 (ST131), an emergent cause of multidrug-resistant extraintestinal infections, has important phylogenetic subsets, notably the H30 and H30Rx subclones, with distinctive resistance profiles and, possibly, clinical associations. To clarify the local prevalence of these ST131 subclones and their associations with antimicrobial resistance, ecological source, and virulence traits, we extensively characterized 233 consecutive E. coli clinical isolates (July and August 2013) from the University of Minnesota Medical Center-Fairview Infectious Diseases and Diagnostic Laboratory, Minneapolis, MN, which serves three adjacent facilities (a children's hospital and low- and high-acuity adult facilities). ST131 accounted for 26% of the study isolates (more than any other clonal group), was distributed similarly by facility, and was closely associated with ciprofloxacin resistance and extended-spectrum β-lactamase (ESBL) production. The H30 and H30Rx subclones accounted for most ST131 isolates and for the association of ST131 with fluoroquinolone resistance and ESBL production. Unlike ST131 per se, these subclones were distributed differentially by hospital, being most prevalent at the high-acuity adult facility and were absent from the children's hospital. The virulence gene profiles of ST131 and its subclones were distinctive and more extensive than those of other fluoroquinolone-resistant or ESBL-producing isolates. Within ST131, bla CTX-M-15 was confined to H30Rx isolates and other bla CTX-M variants to non-Rx H30 isolates. Pulsed-field gel electrophoresis documented a predominance of globally distributed pulsotypes and no local outbreak pattern. These findings help clarify the epidemiology, ecology, and bacterial correlates of the H30 and H30Rx ST131 subclones by documenting a high overall prevalence but significant segregation by facility, strong associations with fluoroquinolone resistance and specific ESBL variants, and distinctive

  7. Pathogenomics of uropathogenic Escherichia coli

    Directory of Open Access Journals (Sweden)

    J Agarwal

    2012-01-01

    Full Text Available Subset of faecal E. coli that can enter, colonize urinary tract and cause infection are known as uropathogenic E. coli (UPEC. UPEC strains act as opportunistic intracellular pathogens taking advantage of host susceptibility using a diverse array of virulence factors. Presence of specific virulence associated genes on genomic/pathogenicity islands and involvement of horizontal gene transfer appears to account for evolution and diversity of UPEC. Recent success in large-scale genome sequencing and comparative genomics has helped in unravelling UPEC pathogenomics. Here we review recent findings regarding virulence characteristics of UPEC and mechanisms involved in pathogenesis of urinary tract infection.

  8. Intramacrophage survival of uropathogenic Escherichia coli: Differences between diverse clinical isolates and between mouse and human macrophages

    KAUST Repository

    Bokil, Nilesh J.

    2011-11-01

    Uropathogenic E. coli (UPEC) are the primary cause of urinary tract infections. Recent studies have demonstrated that UPEC can invade and replicate within epithelial cells, suggesting that this bacterial pathogen may occupy an intracellular niche within the host. Given that many intracellular pathogens target macrophages, we assessed the interactions between UPEC and macrophages. Colonization of the mouse bladder by UPEC strain CFT073 resulted in increased expression of myeloid-restricted genes, consistent with the recruitment of inflammatory macrophages to the site of infection. In in vitro assays, CFT073 was able to survive within primary mouse bone marrow-derived macrophages (BMM) up to 24h post-infection. Three additional well-characterized clinical UPEC isolates associated with distinct UTI symptomatologies displayed variable long-term survival within BMM. UPEC strains UTI89 and VR50, originally isolated from patients with cystitis and asymptomatic bacteriuria respectively, showed elevated bacterial loads in BMM at 24h post-infection as compared to CFT073 and the asymptomatic bacteriuria strain 83972. These differences did not correlate with differential effects on macrophage survival or initial uptake of bacteria. E. coli UTI89 localized to a Lamp1 + vesicular compartment within BMM. In contrast to survival within mouse BMM, intracellular bacterial loads of VR50 were low in both human monocyte-derived macrophages (HMDM) and in human T24 bladder epithelial cells. Collectively, these data suggest that some UPEC isolates may subvert macrophage anti-microbial pathways, and that host species differences may impact on intracellular UPEC survival. © 2011 Elsevier GmbH.

  9. Characterization of pathogenic Escherichia coli isolated from humans in Austria : phenotypes, toxin gene types and epidemiology

    NARCIS (Netherlands)

    Wagner, M; Allerberger, F; Manafi, M; Lindner, G; Friedrich, A W; Sonntag, A-K; Foissy, H

    2004-01-01

    One hundred and ten clinical Escherichia coli isolates of serovar O157 (n = 102) and O26 (n = 8) were characterized for the presence of putative virulence genes by PCR. All but one of these isolates contained the eae gene. The EHEC-hly gene could be detected in all E. coli O157 and in 50% of E. coli

  10. Escherichia coli bacteriuria and contraceptive method.

    Science.gov (United States)

    Hooton, T M; Hillier, S; Johnson, C; Roberts, P L; Stamm, W E

    1991-01-01

    We evaluated the effects of contraceptive method on the occurrence of bacteriuria and vaginal colonization with Escherichia coli in 104 women who were evaluated prior to having sexual intercourse, the morning after intercourse, and 24 hours later. After intercourse, the prevalence of E coli bacteriuria increased slightly in oral contraceptive users but dramatically in both foam and condom users and diaphragm-spermicide users. Twenty-four hours later, the prevalence of bacteriuria remained significantly elevated only in the latter two groups. Similarly, vaginal colonization with E coli was more dramatic and persistent in users of diaphragm-spermicide and foam and condoms. Vaginal colonization with Candida species, enterococci, and staphylococci also increased significantly in diaphragm-spermicide users after intercourse. We conclude that use of the diaphragm with spermicidal jelly or use of a spermicidal foam with a condom markedly alters normal vaginal flora and strongly predisposes users to the development of vaginal colonization and bacteriuria with E coli. PMID:1859519

  11. Dynamics of chromosome segregation in Escherichia coli

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck

    2007-01-01

    Since the 1960’es the conformation and segregation of the chromosome in Escherichia coli has been a subject of interest for many scientists. However, after 40 years of research, we still know incredibly little about how the chromosome is organized inside the cell, how it manages to duplicate this...... and reliable method enabled us to start the analysis on the distribution of various chromosomal loci inside slowly growing cells. With the actual counting and measuring no longer being any problem we could easily analyze 14 loci distributed on the E.coli chromosome. More than 15.000 cells were...... on the P1 par system. Using the new system, which is based on the pMT1 par system from Yersenia pestis, we labeled loci on opposite sides of the E.coli chromosome simultaneously and were able to show that the E.coli chromosome is organized with one chromosomal arm in each cell half. This astounding...

  12. 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...

  13. Genotypic and phenotypic profiles of Escherichia coli isolates belonging to clinical sequence type 131 (ST131), clinical non-ST131, and fecal non-ST131 lineages from India.

    Science.gov (United States)

    Hussain, Arif; Ranjan, Amit; Nandanwar, Nishant; Babbar, Anshu; Jadhav, Savita; Ahmed, Niyaz

    2014-12-01

    In view of the epidemiological success of CTX-M-15-producing lineages of Escherichia coli and particularly of sequence type 131 (ST131), it is of significant interest to explore its prevalence in countries such as India and to determine if antibiotic resistance, virulence, metabolic potential, and/or the genetic architecture of the ST131 isolates differ from those of non-ST131 isolates. A collection of 126 E. coli isolates comprising 43 ST131 E. coli, 40 non-ST131 E. coli, and 43 fecal E. coli isolates collected from a tertiary care hospital in India was analyzed. These isolates were subjected to enterobacterial repetitive intergenic consensus (ERIC)-based fingerprinting, O typing, phylogenetic grouping, antibiotic sensitivity testing, and virulence and antimicrobial resistance gene (VAG) detection. Representative isolates from this collection were also analyzed by multilocus sequence typing (MLST), conjugation, metabolic profiling, biofilm production assay, and zebra fish lethality assay. All of the 43 ST131 E. coli isolates were exclusively associated with phylogenetic group B2 (100%), while most of the clinical non-ST131 and stool non-ST131 E. coli isolates were affiliated with the B2 (38%) and A (58%) phylogenetic groups, respectively. Significantly greater proportions of ST131 isolates (58%) than non-ST131 isolates (clinical and stool E. coli isolates, 5% each) were technically identified to be extraintestinal pathogenic E. coli (ExPEC). The clinical ST131, clinical non-ST131, and stool non-ST131 E. coli isolates exhibited high rates of multidrug resistance (95%, 91%, and 91%, respectively), extended-spectrum-β-lactamase (ESBL) production (86%, 83%, and 91%, respectively), and metallo-β-lactamase (MBL) production (28%, 33%, and 0%, respectively). CTX-M-15 was strongly linked with ESBL production in ST131 isolates (93%), whereas CTX-M-15 plus TEM were present in clinical and stool non-ST131 E. coli isolates. Using MLST, we confirmed the presence of two NDM-1

  14. Antimicrobial susceptibility patterns of clinical Escherichia coli isolates from dogs and cats in the United States: January 2008 through January 2013.

    Science.gov (United States)

    Thungrat, Kamoltip; Price, Stuart B; Carpenter, D Mark; Boothe, Dawn Merton

    2015-09-30

    Escherichia coli is among the most common bacterial pathogens in dogs and cats. The lack of a national monitoring program limits evidence-based empirical antimicrobial choices in the United States. This study describes antimicrobial susceptibility patterns for presumed clinical E. coli isolates from dogs (n=2392) or cats (n=780) collected from six geographic regions in the United States between May 2008 and January 2013. Minimum inhibitory concentrations (MIC) were determined for 17 drugs representing 6 drug classes. Urinary tract isolates were most common (71%). Population MIC distributions were generally bimodal with the second mode above the resistant breakpoint for all drugs except gentamicin, amikacin, and meropenem. The MIC90 exceeded the susceptible breakpoint for ampicillin, amoxicillin-clavulanic acid, cephalothin (surrogate drug for cephalexin), and doxycycline but was below the susceptible breakpoint for all others. None of isolates was susceptible or resistant to all drug tested; 46% were resistant to 1 or 2 antimicrobial categories, and 52% to more than three categories. The resistance percentages were as follows: doxycycline (100%), cephalothin (98%)>ampicillin (48%)>amoxicillin-clavulanic acid (40%)>ticarcillin-clavulanic acid (18%)>cefpodoxime (13%), cefotaxime (12%), cefoxitin (11%), cefazolin (11%), enrofloxacin (10%), chloramphenicol (9.6%)>ciprofloxacin (9.2%), ceftazidime (8.7%), trimethoprim-sulfamethoxazole (7.9%), gentamicin (7.9%)>meropenem (1.5%), amikacin (0.7%) (P<0.05). Resistance to ampicillin and amoxicillin-clavulanic acid was greatest in the South-Central region (P<0.05). E. coli resistance may preclude empirical treatment with doxycycline, cephalexin, ampicillin, or amoxicillin-clavulanic acid. Based on susceptibility patterns, trimethoprim-sulfonamides may be the preferred empirical oral treatment. PMID:26165272

  15. Identification of the newly identified subtilase cytotoxin-encoding gene (subAB2-2) among clinical Shiga toxin-producing Escherichia coli isolates.

    Science.gov (United States)

    Son, Hoang Minh; Duc, Hoang Minh; Honjoh, Ken-Ichi; Miyamoto, Takahisa

    2015-12-01

    Subtilase cytotoxin (SubAB) is an important virulence factor of eae-negative Shiga toxin-producing Escherichia coli (STEC). Three variants of SubAB-encoding genes have been reported in the literature; however, the newly described subAB variant (subAB2-2) was found only in STEC strains from deer meat, sheep, and some wild animals. In this study, subAB variants were detected by PCR and DNA sequencing in 5 out of 12 (41.6%) eae-negative STEC strains isolated from patients. Most subAB-positive STEC strains (80%) harbored the subAB1 gene. The subAB2-2 gene was detected for the first time in the clinical STEC O128:H2 strain. Other virulence genes including stx1a, stx1c, stx2b, ehxA, and tia were also detected in this strain. The DNA sequence analyses of the subAB1 and subAB2-2 genes of the clinical STEC strains showed 99% and 100% identity to those of the reference strains 98NK2 and LM27558stx2, respectively. This is the first report on the detection of the subAB2-2 gene in a clinical STEC isolate. PMID:26588258

  16. Identification and Prevalence of Escherichia coli and Escherichia coli O157: H7 in Foods

    Directory of Open Access Journals (Sweden)

    Ancuta Mihaela Rotar

    2013-11-01

    Full Text Available The objective of this study is to investigate the incidence of Escherichia coli in animal and non-animal foods, and mainly the incidence of the serotype O157: H7 producing verotoxin. The presence of common Escherichia coli and Escherichia coli O157: H7 in various foods (of animal and non animal origin was performed in Transylvania area. We analyzed a total of one hundred forty-one samples of minced meat, one hundred twenty-six samples of meat , twenty six samples of meat products, five samples of alcoholic beverages, three samples of seafood, one hundred samples of cheese from pasteurized milk, seventeen samples of butter, four samples of vegetables and one sample of milk powder, using the standard cultural method and Vidas Eco method for E. coli O157: H7 strains. E. coli was identified in 50 samples of minced meat, 55 samples of meat prepared, 4 samples of meat products, 2 samples of alcoholic beverages, 25 samples of cheese from pasteurized milk, 6 samples of butter and 1 sample of vegetables. In this study were not been identified any foods contaminated with the E. coli O157: H7 serotype. The results of this reasearch have demostrated that E. coli wich represents a hygienic indicator of recent food contamination, can be destroyed with heat treatment and hygienic handling of foods. Our country over the years has been among the few countries where the incidence of the E. coli O157: H7 serotype has been minimal.

  17. Pet, an Autotransporter Enterotoxin from Enteroaggregative Escherichia coli

    OpenAIRE

    Eslava, Carlos; Navarro-García, Fernando; Czeczulin, John R.; Henderson, Ian R.; Cravioto, Alejandro; James P. Nataro

    1998-01-01

    Enteroaggregative Escherichia coli (EAEC) is an emerging cause of diarrheal illness. Clinical data suggest that diarrhea caused by EAEC is predominantly secretory in nature, but the responsible enterotoxin has not been described. Work from our laboratories has implicated a ca. 108-kDa protein as a heat-labile enterotoxin and cytotoxin, as evidenced by rises in short-circuit current and falls in tissue resistance in rat jejunal tissue mounted in an Ussing chamber. Here we report the genetic cl...

  18. Occurrence of pathogenic and faecal Escherichia coli in layer hens

    Directory of Open Access Journals (Sweden)

    Silvia Tagliabue

    2010-01-01

    Full Text Available A total of 117 Escherichia coli from colibacillosis affected (APEC and clinically healthy birds (AFEC were serotyped and tested for the presence of virulence genes: iss, tsh, cva. A total of 54.5% E. Coli were typeable and 15 different serogroups were identified. The most common serogroups among APEC strains were O78, O2 and O128, whereas O139 was predominant in faecal strains from healthy birds. Iss, tsh e cva were more frequently detected among the septicaemic E. coli strains. The association of virulence genes was observed. Particularly, the pathotype iss-tsh-cva was present in 46.5% of APEC strains. Referring to serogroups, E. coli O78 and O2 originating from colibacillosis affected birds were always isstsh- cva positive but did not share virulence genes when they came from healthy birds.

  19. Designed Phosphoprotein Recognition in Escherichia coli

    OpenAIRE

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

    2014-01-01

    Protein phosphorylation is a central biological mechanism for cellular adaptation to environmental changes. Dysregulation of phosphorylation signaling is implicated in a wide variety of diseases. Thus, the ability to detect and quantify protein phosphorylation is highly desirable for both diagnostic and research applications. Here we present a general strategy for detecting phosphopeptide–protein interactions in Escherichia coli. We first redesign a model tetratricopeptide repeat (TPR) protei...

  20. Endonuclease IV (nfo) mutant of Escherichia coli.

    OpenAIRE

    Cunningham, R P; Saporito, S M; Spitzer, S G; Weiss, B

    1986-01-01

    A cloned gene, designated nfo, caused overproduction of an EDTA-resistant endonuclease specific for apurinic-apyrimidinic sites in DNA. The sedimentation coefficient of the enzyme was similar to that of endonuclease IV. An insertion mutation was constructed in vitro and transferred from a plasmid to the Escherichia coli chromosome. nfo mutants had an increased sensitivity to the alkylating agents methyl methanesulfonate and mitomycin C and to the oxidants tert-butyl hydroperoxide and bleomyci...

  1. Endonuclease III (nth) mutants of Escherichia coli.

    OpenAIRE

    Cunningham, R P; Weiss, B

    1985-01-01

    Two strains that overproduce endonuclease III were found in a colony bank containing hybrid ColE1-Escherichia coli plasmids. The enzyme was identified in crude extracts by the degradation of partially depyrimidinated DNA in the presence of EDTA, by its sedimentation velocity, and by its associated thymine glycol-DNA glycosylase activity. An insertion mutation was produced by cloning the kanamycin-resistance gene of Tn5 into the plasmid copy of the nth gene. The mutation was then transferred t...

  2. Growth of Escherichia coli on nanocrystalline diamond

    Czech Academy of Sciences Publication Activity Database

    Jurková, Blanka; Kozak, Halyna; Artemenko, Anna; Ukraintsev, Egor; Beranová, J.; Konopásek, I.; Kromka, Alexander

    Ostrava: TANGER Ltd, 2015 - (Shrbená, J.; Zbořil, R.), s. 4318 ISBN 9788087294598. [NANOCON 2015. International Conference /7./. Brno (CZ), 14.10.2015-16.10.2015] R&D Projects: GA ČR GA15-01687S Institutional support: RVO:68378271 Keywords : nanocrystalline diamond * bacteria * Escherichia coli * anti-adhesive * CDC Bioreactor Subject RIV: BM - Solid Matter Physics ; Magnetism

  3. 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.

  4. Action of sodium deoxycholate on Escherichia coli

    International Nuclear Information System (INIS)

    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-14C]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

  5. 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.

  6. In vitro antibacterial activity of medicinal plant extracts against Escherichia coli strains from human clinical specimens and interactions with antimicrobial drugs.

    Science.gov (United States)

    Ushimaru, P I; Barbosa, L N; Fernandes, A A H; Di Stasi, L C; Fernandes, A

    2012-01-01

    The biological properties of medicinal plants have been documented worldwide for many centuries. We aimed to evaluate interactions between crude extracts from Psidium guajava, Zingiber officinale, Cymbopogon citratus, Caryophyllus aromaticus, Mikania glomerata and Allium sativum samples and antimicrobial drugs against Escherichia coli strains. The susceptibility test performed was disc diffusion, and crude extracts were diluted (%v/v) into Müller-Hinton agar (MHA) at one quarter of the minimal inhibitory concentration for 90% (MIC(90%)) of E. coli strains found previously. Synergistic interactions were observed between C. citratus and polymyxin, and A. sativum extracts and gentamicin. The crude A. sativum extract was the only one that did not show any antagonism with the antimicrobial drugs. The results thus showed the potential use of these medicinal plants against E. coli strains, although antagonism with antimicrobial drugs is a negative aspect in the combined therapy of infectious diseases caused by E. coli. PMID:22011190

  7. Evaluating Antimicrobial Effects of Centaurea Plant’s Essential Oil on Pathogenic Bacteria: Staphylococcus Aureus, Staphylococcus Epidermidis, and Escherichia Coli Isolated from Clinical Specimens

    Directory of Open Access Journals (Sweden)

    Haedeh Mobaiyen

    2016-03-01

    Full Text Available Background & Objectives :Nowadays, development of drug resistance against chemical antimicrobial drugs has attracted attention using medicinal plants in treatment of infections. The aim of this study is to evaluate the antimicrobial effects of two species of Centaurea plant’s essential oil on drug resistant clinical isolates of three pathogenic isolates. Materials & Methods :The studied plants were collected from Marand city in East Azerbaijan, Iran and were confirmed as Centaurea Depressa M.B. and Centaurea Cyanus L. by botanists of Iran Agriculture Organization. The essential oil of these plants (Stems and leaf were extracted via steam distillation method by Clevenger, and their antimicrobial effects were studied by well diffusion method in the abovementioned bacteria. The components of essential oil were identified by injection to gas chromatography linked to mass spectrometry (GC/M. Results :The results of this study prove that the essential oils from the abovementioned plants have bactericidal effects. The most antibacterial effect is observed in Escherichia coli strains. The results of GC/MS chromatography reveal that the essential oils of Centaurea Depressa M.B. and Centaurea Cyanus L. have 28 and 32 compounds, respectively. Conclusion: This study confirmed that the grasses could be used in medicinal plants group with antibacterial properties. However, their effects in vivo must be evaluated and the most effective component of them must be identified carefully so that they can be applied commonly as an alternative synthetic drug in treating infections.

  8. Escherichia coli strain Nissle 1917 ameliorates experimental colitis by modulating intestinal permeability, the inflammatory response and clinical signs in a faecal transplantation model.

    Science.gov (United States)

    Souza, Éricka L; Elian, Samir D; Paula, Laís M; Garcia, Cristiana C; Vieira, Angélica T; Teixeira, Mauro M; Arantes, Rosa M; Nicoli, Jacques R; Martins, Flaviano S

    2016-03-01

    Inflammatory bowel diseases (IBDs) are a group of inflammatory conditions of the gut that include ulcerative colitis and Crohn's disease. Probiotics are live micro-organisms that may be used as adjuvant therapy for patients with IBD. The aim of this study was to evaluate the effect of prophylactic ingestion of Escherichia coli strain Nissle 1917 (EcN) in a murine model of colitis. For induction of colitis, mice were given a 3.5 % dextran sodium sulfate (DSS) solution for 7 days in drinking water. EcN administration to mice subjected to DSS-induced colitis resulted in significant reduction in clinical and histopathological signs of disease and preservation of intestinal permeability. We observed reduced inflammation, as assessed by reduced levels of neutrophils, eosinophils, chemokines and cytokines. We observed an increase in the number of regulatory T-cells in Peyer's patches. Germ-free mice received faecal content from control or EcN-treated mice and were then subjected to DSS-induced colitis. We observed protection from colitis in animals that were colonized with faecal content from EcN-treated mice. These results suggest that preventative oral administration of EcN or faecal microbiota transplantation with EcN-containing microbiota ameliorates DSS-induced colitis by modifying inflammatory responsiveness to DSS. PMID:26758971

  9. Inhibitor-Sensitive AmpC β-Lactamase Variant Produced by an Escherichia coli Clinical Isolate Resistant to Oxyiminocephalosporins and Cephamycins

    OpenAIRE

    Doi, Yohei; Wachino, Jun-ichi; Ishiguro, Masaji; Kurokawa, Hiroshi; Yamane, Kunikazu; Shibata, Naohiro; Shibayama, Keigo; Yokoyama, Keiko; Kato, Haru; Yagi, Tetsuya; Arakawa, Yoshichika

    2004-01-01

    Escherichia coli HKY28, a ceftazidime-resistant strain isolated from a urine specimen in Japan, produced an inhibitor-sensitive AmpC β-lactamase variant. The deduced amino acid sequence of the enzyme contained a number of substitutions and a tripeptide deletion (Gly286-Ser287-Asp288) compared with the sequence of native AmpC of E. coli. When the deletion was reverted by a 9-base insertion at the relevant site of ampC in the clone, the typical inhibitor-resistant phenotype of AmpC was restored...

  10. Characterization of AmpC, CTX-M and MBLs types of β-lactamases in clinical isolates of Klebsiella pneumoniae and Escherichia coli producing Extended Spectrum β-lactamases in Kerman, Iran

    OpenAIRE

    Mansouri, Shahla; Kalantar Neyestanaki, Davood; Shokoohi, Mostafa; Halimi, Shahnaz; Beigverdi, Reza; Rezagholezadeh, Fereshteh; Hashemi, Ali

    2014-01-01

    Background: Extended spectrum β-lactamases (ESBLs) and AmpC β-lactamases enzyme are major sources of resistance to β-lactam antibiotics especially in Enterobacteriaceae such as Escherichia coli and Klebsiella pneumoniae. Increasing frequency of the co-existence of ESBLs with AmpC-β-lactamases in bacteria is a serious threat for treating bacterial infections. Objectives: The aim of this study was to determine the presence of AmpC and CTX-M types of β-lactamases in clinical isolates of E. coli ...

  11. Urease genes in non-O157 Shiga toxin-producing Escherichia coli : mostly silent but valuable markers for pathogenicity

    NARCIS (Netherlands)

    Friedrich, A W; Lukas, R; Mellmann, A; Köck, R; Zhang, W; Mathys, W; Bielaszewska, M; Karch, H

    2006-01-01

    The distribution of ureC was investigated among 294 Escherichia coli isolates, comprising 72 strains from the E. coli standard reference collection (ECOR), 62 strains from the diarrhoeagenic E. coli (DEC) collection, and 160 clinical isolates of Shiga toxin-producing E. coli (STEC). The ureC gene wa

  12. Comparison of antibiotic resistance patterns in collections of Escherichia coli and Proteus mirabilis uropathogenic strains

    OpenAIRE

    Adamus-Bialek, Wioletta; Zajac, Elzbieta; Parniewski, Pawel; Kaca, Wieslaw

    2013-01-01

    Escherichia coli and Proteus mirabilis are important urinary tract pathogens. The constant increase in the antibiotic resistance of clinical bacterial strains has become an important clinical problem. The aim of this study was to compare the antibiotic resistance of 141 clinical (Sweden and Poland) and 42 laboratory (Czech Republic) P. mirabilis strains and 129 clinical (Poland) uropathogenic E. coli strains. The proportion of unique versus diverse patterns in Swedish clinical and laboratory ...

  13. Ethanol production by Escherichia coli KO11; Producao de etanol por Escherichia coli KO11

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Katia Gianni de Carvalho [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas. Lab. de Microbiologia de Alimentos]. E-mail: gianni@usp.br; Takahashi, Caroline Maki; Alterthum, Flavio [Sao Paulo Univ., SP (Brazil). Inst. de Ciencias Biomedicas. Dept. de Microbiologia

    2002-08-01

    This paper discusses the potential use of Escherichia coli KO11 in production of ethanol, based on observation that this organism can efficiently metabolize sugar complex moistures obtained from the acid hydrolysis of lignocellulose materials such as sugar-cane bagasse, corncob, corn husk, Pinus sp and oak wood.

  14. Expression of maize prolamins in Escherichia Coli

    International Nuclear Information System (INIS)

    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 32P-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)

  15. Global gene expression in Escherichia coli biofilms

    DEFF Research Database (Denmark)

    Schembri, Mark; Kjærgaard, K.; Klemm, Per

    2003-01-01

    antimicrobial treatments and host immune defence responses. Escherichia coli has been used as a model organism to study the mechanisms of growth within adhered communities. In this study, we use DNA microarray technology to examine the global gene expression profile of E. coli during sessile growth compared...... with planktonic growth. Genes encoding proteins involved in adhesion (type 1 fimbriae) and, in particular, autoaggregation (Antigen 43) were highly expressed in the adhered population in a manner that is consistent with current models of sessile community development. Several novel gene clusters were...... induced upon the transition to biofilm growth, and these included genes expressed under oxygen-limiting conditions, genes encoding (putative) transport proteins, putative oxidoreductases and genes associated with enhanced heavy metal resistance. Of particular interest was the observation that many of the...

  16. Antimicrobial resistance, genotypic characterization and pulsed-field gel electrophoresis typing of extended spectrum β-lactamases-producing clinical Escherichia coli strains in Macao, China

    Institute of Scientific and Technical Information of China (English)

    YE Qian-hong; LAU Ying; LIANG Bin; TIAN Su-fei

    2011-01-01

    Background The rise of the production of CTX-M class extended spectrum β-lactamases (ESBLs) has been well documented in traveling countries but no data are found for Macao,an international travel city.The objectives of this study were to identify the antimicrobial resistance pattern,and determine the prevalence,genotype and clonal relationship of ESBLs in 209 clinical Escherichia coli strains from Macao,China.Methods Antimicrobial susceptibility test was performed to determine the resistance patterns of the isolates using the disk diffusion method with 17 antimicrobial agents.Phenotypic detection was screened and confirmed according to the Clinical and Laboratory Standards Institute.Genotypic characterization was detected by isoelectric focusing analysis,polymerase chain reaction and sequencing.The clonal relationship between the different ESBL isolates was studied by pulsed-field gel electrophoresis (PFGE).Results Imipenem and meropenem exhibited 100% susceptible among 209 strains.Overall,82.3%,67.3%,52.9%,51.2% and 51.0% of the isolates displayed resistance to ampicillin,tetracylcline,ciprofloxacin,sulfamethoxazole trimethoprin and gentamycin.The prevalence rate of ESBLs was 30.1%.Antibiotic resistances were found to be significantly higher among the ESBL producing group compared to non-ESBL producing group.We detected CTX-M-14 to be the major genotypic characterization of ESBLs (76.2%).Two strains showed indistinguishable patterns by PFGE.Conclusions The prevalence of antimicrobial resistance is alarming high in Macao.Antimicrobial resistance is significantly higher among the ESBL producing group.This study documented CTX-M-14 as the predominant ESBL type.Although indistinguishable pattern was found between two strains,it was too small to decide whether any of the investigated strains was epidemic.Our findings may be also pertinent for other geographic areas undergoing similar travel characteristics to understand the corresponding effects on bacterial

  17. A standardised challenge model with an enterotoxigenic F4+ Escherichia coli strain in piglets assessing clinical traits and faecal shedding of fae and est-II toxin genes.

    Science.gov (United States)

    Spitzer, Franz; Vahjen, Wilfried; Pieper, Robert; Martinez-Vallespin, Beatriz; Zentek, Jürgen

    2014-12-01

    This study evaluated the effect of five feed additives on post weaning diarrhoea (PWD) in piglets challenged 3 d after weaning with an enterotoxigenic Escherichia coli strain (ETEC). In three experimental runs, a total of 84 piglets was weaned at 21 days of age and randomly assigned to seven treatments. As dietary treatment, piglets were fed a basal diet or diets with addition of bovine colostrum (0.2%), pineapple stem extract containing bromelain (0.2%), an autolysed yeast preparation (Saccharomyces cerevisiae) (0.1%), a combination of organic acids (0.7%) and a phytogenic product with thyme essential oil (0.015%). A porcine ETEC, serotype O149:K91:K88ac was given twice via oral infection on day 3 after weaning at 10(10) colony forming units/animal. One group of piglets was fed the basal diet without ETEC challenge. Traits included clinical sores, body temperature, faecal scoring and determination of faecal dry matter and the shedding of fae and est-II ETEC toxin genes. After weaning, non-challenged control piglets did not show signs of diarrhoea or impaired health, while the majority of infected piglets had a drop in body temperature, signs of diarrhoea and impaired general health. Mortality, the decrease of faecal dry matter and shedding of the toxin genes fae and est-II were not affected by the different additives. In conclusion, the ETEC challenge model induced distinct clinical signs of PWD in piglets, but the tested feed additives had no preventive effect under these conditions. PMID:25313936

  18. Escherichia coli O157 infections and unpasteurised milk

    NARCIS (Netherlands)

    Allerberger, F; Wagner, M; Schweiger, P; Rammer, H P; Resch, A; Dierich, M P; Friedrich, A W; Karch, H

    2001-01-01

    We report on two children with Escherichia coli O157 infection, one of whom developed haemolytic uraemic syndrome (HUS). Both had drunk raw cows or goats milk in the week before their illness. Molecular subtyping identified a sorbitol fermenting Escherichia coli O157:H isolate from a dairy cow. This

  19. Chromatin architecture and gene expression in Escherichia coli

    DEFF Research Database (Denmark)

    Willenbrock, Hanni; Ussery, David

    2004-01-01

    Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli.......Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli....

  20. Escherichia coli clearance after splenic autotransplants

    International Nuclear Information System (INIS)

    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

  1. Trends in Expanded-Spectrum Cephalosporin-Resistant Escherichia coli and Klebsiella pneumoniae among Dutch Clinical Isolates, from 2008 to 2012.

    Directory of Open Access Journals (Sweden)

    Matthijs van der Steen

    Full Text Available We investigated time trends in extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella pneumoniae isolates from different patient settings in The Netherlands from 2008-2012. E. coli and K. pneumoniae isolates from blood and urine samples of patients > = 18 years were selected from the Dutch Infectious Disease Surveillance System-Antimicrobial Resistance (ISIS-AR database. We used multivariable Poisson regression to study the rate per year of blood stream infections by susceptible and resistant isolates, and generalized estimating equation (GEE log-binomial regression for trends in the proportion of extended-spectrum cephalosporin-resistant isolates. Susceptibility data of 197,513 E. coli and 38,244 K. pneumoniae isolates were included. The proportion of extended-spectrum cephalosporin-resistant E. coli and K. pneumoniae isolates from urine and blood samples increased in all patient settings, except for K. pneumoniae isolates from patients admitted to intensive care units. For K. pneumoniae, there was a different time trend between various patient groups (p<0.01, with a significantly higher increase in extended-spectrum cephalosporin-resistant isolates from patients attending a general practitioner than in isolates from hospitalized patients. For E. coli, the increasing time trends did not differ among different patient groups. This nationwide study shows a general increase in extended-spectrum cephalosporin-resistant E. coli and K. pneumoniae isolates. However, differences in trends between E. coli en K. pneumoniae underline the importance of E. coli as a community-pathogen and its subsequent influence on hospital resistance level, while for K. pneumoniae the level of resistance within the hospital seems less influenced by the resistance trends in the community.

  2. Mechanisms of Reduced Susceptibility to Ciprofloxacin in Escherichia coli Isolates from Canadian Hospitals

    Directory of Open Access Journals (Sweden)

    Patricia J Baudry-Simner

    2012-01-01

    Full Text Available OBJECTIVE: To determine whether plasmid-mediated quinolone resistance (PMQR determinants play a role in the increasing resistance to fluoroquinolones among Escherichia coli isolates in Canadian hospitals, and to determine the mechanisms of reduced susceptibility to ciprofloxacin in a recent collection of 190 clinical E coli isolates.

  3. Production of glycoprotein vaccines in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ihssen Julian

    2010-08-01

    Full Text Available Abstract Background Conjugate vaccines in which polysaccharide antigens are covalently linked to carrier proteins belong to the most effective and safest vaccines against bacterial pathogens. State-of-the art production of conjugate vaccines using chemical methods is a laborious, multi-step process. In vivo enzymatic coupling using the general glycosylation pathway of Campylobacter jejuni in recombinant Escherichia coli has been suggested as a simpler method for producing conjugate vaccines. In this study we describe the in vivo biosynthesis of two novel conjugate vaccine candidates against Shigella dysenteriae type 1, an important bacterial pathogen causing severe gastro-intestinal disease states mainly in developing countries. Results Two different periplasmic carrier proteins, AcrA from C. jejuni and a toxoid form of Pseudomonas aeruginosa exotoxin were glycosylated with Shigella O antigens in E. coli. Starting from shake flask cultivation in standard complex medium a lab-scale fed-batch process was developed for glycoconjugate production. It was found that efficiency of glycosylation but not carrier protein expression was highly susceptible to the physiological state at induction. After induction glycoconjugates generally appeared later than unglycosylated carrier protein, suggesting that glycosylation was the rate-limiting step for synthesis of conjugate vaccines in E. coli. Glycoconjugate synthesis, in particular expression of oligosaccharyltransferase PglB, strongly inhibited growth of E. coli cells after induction, making it necessary to separate biomass growth and recombinant protein expression phases. With a simple pulse and linear feed strategy and the use of semi-defined glycerol medium, volumetric glycoconjugate yield was increased 30 to 50-fold. Conclusions The presented data demonstrate that glycosylated proteins can be produced in recombinant E. coli at a larger scale. The described methodologies constitute an important step

  4. Shigella Strains Are Not Clones of Escherichia coli but Sister Species in the Genus Escherichia

    OpenAIRE

    Zuo, Guanghong; Xu, Zhao; Hao, Bailin

    2012-01-01

    Shigella species and Escherichia coli are closely related organisms. Early phenotyping experiments and several recent molecular studies put Shigella within the species E. coli. However, the whole-genome-based, alignment-free and parameter-free CVTree approach shows convincingly that four established Shigella species, Shigella boydii, Shigella sonnei, Shigella felxneri and Shigella dysenteriae, are distinct from E. coli strains, and form sister species to E. coli within the genus Escherichia. ...

  5. Role of Escherichia coli in Biofuel Production

    Science.gov (United States)

    Koppolu, Veerendra; Vasigala, Veneela KR

    2016-01-01

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

  6. Regulation of alcohol fermentation by Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D.P.

    1989-01-01

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

  7. [Population genomic researches of Escherichia coli].

    Science.gov (United States)

    Wu, Y R; Yang, R F; Cui, Y J

    2016-06-01

    Population genomics, an interdiscipline of genomics and population genetics, is booming in recent years with the rapid growth number of deciphered genomes and revolutionizes the understanding of bacterial population diversity and evolution dynamics. It also largely improves the prevention and control of infectious disease through providing more accurate genotyping and source-tracing results and more comprehensive characteristics of emerging pathogens. In this review, taking one of the best characterized bacteria, Escherichia coli, as model, we reviewed the phylogenetic relationship across its five major populations (designated A, B1, B2, D and E); and summarized researches on molecular mutation rate, selection signals, and patterns of adaptive evolution. We also described the application of population genomics in responding against large-scale outbreaks of E. coli O157:H7 and E. coli O104:H4. These results indicated that, although being a novel discipline, population genomics has played an important role in deciphering bacterial population structures, exploring evolutionary patterns and combating emerging infectious diseases. PMID:27256740

  8. Role of Escherichia coli in Biofuel Production.

    Science.gov (United States)

    Koppolu, Veerendra; Vasigala, Veneela Kr

    2016-01-01

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

  9. Dynamics of uterine infections with Escherichia coli, Streptococcus uberis and Trueperella pyogenes in post-partum dairy cows and their association with clinical endometritis.

    Science.gov (United States)

    Wagener, K; Grunert, T; Prunner, I; Ehling-Schulz, M; Drillich, M

    2014-12-01

    The diversity and dynamics of the uterine microbiota of dairy cows are poorly understood although it is becoming increasingly evident that they play a crucial role in the development of metritis and endometritis. Fourier-transform infrared (FTIR) spectroscopy was used to monitor the bovine microbiota of 40 cows on the day of calving and days 3, 9, 15, and 21 after parturition, and to investigate the associations of selected species with clinical endometritis (CE). Trueperella pyogenes (43.5%), Escherichia coli (21.5%), Bacillus spp. (21.0%) and Streptococcus uberis (18.5%) were the most frequently isolated microbes. Analyses of different sampling time points revealed that the presence of S. uberis on day 3 increased the risk of subsequent T. pyogenes infection on day 9 (odds ratio [OR] = 5.1, 95% confidence interval [CI] = 1.2-22.6). T. pyogenes infection (OR = 36.0, 95% CI = 3.8-343.2) and retained fetal membranes (RFM) (OR = 12.4, 95%CI = 1.4-112.7) were significant risk factors for CE. Cows with S. uberis on day 3 tended to have greater odds of CE than S. uberis-negative cows (OR = 7.1, 95% CI = 0.9-55.6). Chemometric analysis revealed significant differences in the metabolic profile of S. uberis strains isolated from cows with different vaginal discharge scores. This is the first study showing the association of specific S. uberis subtypes with the uterine health status of post-partum dairy cows. The study demonstrates that uterine clearance is a highly dynamic process, during which time bacteria show distinct patterns of progression, and provides information about interactions between bacterial species involved in the occurrence of CE. PMID:25439441

  10. The cobalamin (coenzyme B12) biosynthetic genes of Escherichia coli.

    OpenAIRE

    Lawrence, J. G.; Roth, J R

    1995-01-01

    The enteric bacterium Escherichia coli synthesizes cobalamin (coenzyme B12) only when provided with the complex intermediate cobinamide. Three cobalamin biosynthetic genes have been cloned from Escherichia coli K-12, and their nucleotide sequences have been determined. The three genes form an operon (cob) under the control of several promoters and are induced by cobinamide, a precursor of cobalamin. The cob operon of E. coli comprises the cobU gene, encoding the bifunctional cobinamide kinase...

  11. Antimicrobial activity of essential oils of cultivated oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) against clinical isolates of Escherichia coli, Klebsiella oxytoca, and Klebsiella pneumoniae

    Science.gov (United States)

    Fournomiti, Maria; Kimbaris, Athanasios; Mantzourani, Ioanna; Plessas, Stavros; Theodoridou, Irene; Papaemmanouil, Virginia; Kapsiotis, Ioannis; Panopoulou, Maria; Stavropoulou, Elisavet; Bezirtzoglou, Eugenia E.; Alexopoulos, Athanasios

    2015-01-01

    Background Oregano (Origanum vulgare), sage (Salvia officinalis), and thyme (Thymus vulgaris) are aromatic plants with ornamental, culinary, and phytotherapeutic use all over the world. In Europe, they are traditionally used in the southern countries, particularly in the Mediterranean region. The antimicrobial activities of the essential oils (EOs) derived from those plants have captured the attention of scientists as they could be used as alternatives to the increasing resistance of traditional antibiotics against pathogen infections. Therefore, significant interest in the cultivation of various aromatic and medicinal plants is recorded during the last years. However, to gain a proper and marketable chemotype various factors during the cultivation should be considered as the geographical morphology, climatic, and farming conditions. In this frame, we have studied the antimicrobial efficiency of the EOs from oregano, sage, and thyme cultivated under different conditions in a region of NE Greece in comparison to the data available in literature. Methods Plants were purchased from a certified supplier, planted, and cultivated in an experimental field under different conditions and harvested after 9 months. EOs were extracted by using a Clevenger apparatus and tested for their antibacterial properties (Minimum inhibitory concentration – MIC) against clinical isolates of multidrug resistant Escherichia coli (n=27), Klebsiella oxytoca (n=7), and Klebsiella pneumoniae (n=16) strains by using the broth microdilution assay. Results Our results showed that the most sensitive organism was K. oxytoca with a mean value of MIC of 0.9 µg/mL for oregano EOs and 8.1 µg/mL for thyme. The second most sensitive strain was K. pneumoniae with mean MIC values of 9.5 µg/mL for thyme and 73.5 µg/mL for oregano EOs. E. coli strains were among the most resistant to EOs antimicrobial action as the observed MICs were 24.8–28.6 µg/mL for thyme and above 125 µg/mL for thyme and sage

  12. Antimicrobial activity of essential oils of cultivated oregano (Origanum vulgare, sage (Salvia officinalis, and thyme (Thymus vulgaris against clinical isolates of Escherichia coli, Klebsiella oxytoca, and Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    Maria Fournomiti

    2015-04-01

    Full Text Available Background: Oregano (Origanum vulgare, sage (Salvia officinalis, and thyme (Thymus vulgaris are aromatic plants with ornamental, culinary, and phytotherapeutic use all over the world. In Europe, they are traditionally used in the southern countries, particularly in the Mediterranean region. The antimicrobial activities of the essential oils (EOs derived from those plants have captured the attention of scientists as they could be used as alternatives to the increasing resistance of traditional antibiotics against pathogen infections. Therefore, significant interest in the cultivation of various aromatic and medicinal plants is recorded during the last years. However, to gain a proper and marketable chemotype various factors during the cultivation should be considered as the geographical morphology, climatic, and farming conditions. In this frame, we have studied the antimicrobial efficiency of the EOs from oregano, sage, and thyme cultivated under different conditions in a region of NE Greece in comparison to the data available in literature. Methods: Plants were purchased from a certified supplier, planted, and cultivated in an experimental field under different conditions and harvested after 9 months. EOs were extracted by using a Clevenger apparatus and tested for their antibacterial properties (Minimum inhibitory concentration – MIC against clinical isolates of multidrug resistant Escherichia coli (n=27, Klebsiella oxytoca (n=7, and Klebsiella pneumoniae (n=16 strains by using the broth microdilution assay. Results: Our results showed that the most sensitive organism was K. oxytoca with a mean value of MIC of 0.9 µg/mL for oregano EOs and 8.1 µg/mL for thyme. The second most sensitive strain was K. pneumoniae with mean MIC values of 9.5 µg/mL for thyme and 73.5 µg/mL for oregano EOs. E. coli strains were among the most resistant to EOs antimicrobial action as the observed MICs were 24.8–28.6 µg/mL for thyme and above 125 µg/mL for

  13. In vitro activity of rifaximin against clinical isolates of Escherichia coli and other enteropathogenic bacteria isolated from travellers returning to the UK.

    Science.gov (United States)

    Hopkins, Katie L; Mushtaq, Shazad; Richardson, Judith F; Doumith, Michel; de Pinna, Elizabeth; Cheasty, Tom; Wain, John; Livermore, David M; Woodford, Neil

    2014-05-01

    Rifaximin is licensed in the EU and USA for treating travellers' diarrhoea caused by non-invasive bacteria. Selection for resistance mechanisms of public health significance might occur if these are linked to rifamycin resistance. Rifaximin MICs were determined by agar dilution for 90 isolates each of Escherichia coli, Shigella spp., nontyphoidal Salmonella enterica, typhoidal S. enterica and Campylobacter spp., an additional 60 E. coli with CTX-M ESBLs isolated from patients with travellers' diarrhoea, and 30 non-diarrhoeal carbapenemase-producing E. coli. Comparators were rifampicin, ciprofloxacin, azithromycin, trimethoprim/sulfamethoxazole and doxycycline. Isolates with rifaximin MICs>32 mg/L were screened for arr genes, and critical rpoB regions were sequenced. Rifaximin was active at ≤32 mg/L against 436/450 (96.9%) diverse Enterobacteriaceae, whereas 81/90 (90%) Campylobacter spp. were resistant to rifaximin at ≥128 mg/L. Rifaximin MICs were ≥128 mg/L for two Shigella and five MDR E. coli producing NDM (n = 3), OXA-48 (n = 1) or CTX-M-15 (n = 1). Two of the five MDR E. coli had plasmids harbouring arr-2 together with bla(NDM), and two (one each with bla(NDM) and bla(CTX-M-15)) had His526Asn substitutions in RpoB. The rifamycin resistance mechanism remained undefined in one MDR E. coli isolate (with bla(OXA-48)) and the two Shigella isolates. Rifaximin showed good in vitro activity against diverse Enterobacteriaceae but was largely inactive against Campylobacter spp. Rifaximin has potential to co-select MDR E. coli in the gut flora, but much stronger associations were seen between ESBL and/or carbapenemase production and resistance to alternative treatments for travellers' diarrhoea, notably ciprofloxacin and azithromycin. PMID:24661532

  14. Clinical and bacteriological effects of pivmecillinam for ESBL-producing Escherichia coli or Klebsiella pneumoniae in urinary tract infections

    DEFF Research Database (Denmark)

    Jansåker, Filip; Frimodt-Møller, Niels; Sjögren, Ingegerd; Knudsen, Inge Jenny Dahl

    2014-01-01

    The prevalence of urinary tract infections (UTIs) caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is increasing and the therapeutic options are limited, especially in primary care. Recent indications have suggested pivmecillinam to be a suitable option. Here, we...... evaluated the clinical and bacteriological effects of pivmecillinam in UTIs caused by ESBL-producing Enterobacteriaceae....

  15. 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.

  16. Prevalence of Shiga toxin genes and intimin genes in uropathogenic Escherichia coli

    OpenAIRE

    Kobra Abbasi; Elahe Tajbakhsh

    2015-01-01

    Objective: To identify stx1, stx2 and eaeA genes in Escherichia coli (E. coli) strains isolated from urine samples in Shahrekord, Iran. Methods: In this cross study a total of 147 middle urine samples from patients with symptoms of urinary tract infection (UTI), referred to clinical laboratories of Shahrekord were studied. Taken samples were cultured to detect Shigatoxin-producing strains and finally 76 E. coli isolates were identified using the standard biochemical tests as we...

  17. Cervical celullitis in broiler chickens for Escherichia coli/
    Celulite cervical em frangos de corte causada por Escherichia coli

    OpenAIRE

    Ivens Gomes Guimarães; Milene Martins Berbel; Marcia Marinho Luzardo; Werner Okano; Claudia Yurika Tamehiro; Benito Guimarães de Brito

    2002-01-01

    In this paper was report the isolation of Escherichia coli in broiler chickens with cellulitis in the cervical region. It was carried through the isolation of E. coli of the lesion of cellulitis from broilers and carried through histopathological examination of skin that had characterized the lesion. Focal ulcerations of epidermis, fibrin in dermis and difuse infiltrated by lymphocytes and heterophils on subcutaneous tissues.Neste trabalho, relata-se o isolamento de Escherichia coli em frango...

  18. Genotypic and Phenotypic Profiles of Escherichia coli Isolates Belonging to Clinical Sequence Type 131 (ST131), Clinical Non-ST131, and Fecal Non-ST131 Lineages from India

    OpenAIRE

    Hussain, Arif; Ranjan, Amit; Nandanwar, Nishant; Babbar, Anshu; Jadhav, Savita; Ahmed, Niyaz

    2014-01-01

    In view of the epidemiological success of CTX-M-15-producing lineages of Escherichia coli and particularly of sequence type 131 (ST131), it is of significant interest to explore its prevalence in countries such as India and to determine if antibiotic resistance, virulence, metabolic potential, and/or the genetic architecture of the ST131 isolates differ from those of non-ST131 isolates. A collection of 126 E. coli isolates comprising 43 ST131 E. coli, 40 non-ST131 E. coli, and 43 fecal E. col...

  19. Inducible cephalosporinase production in clinical isolates of Enterobacter cloacae is controlled by a regulatory gene that has been deleted from Escherichia coli.

    OpenAIRE

    Honoré, N; Nicolas, M H; Cole, S T

    1986-01-01

    Cephalosporin hyper-resistant Enterobacter cloacae strains are isolated with increasing frequency from hospital infections. Resistance is principally due to the chromosomal ampC gene encoding a cephalosporinase. In contrast to Escherichia coli which expresses ampC constitutively from a promoter located in the upstream frdD gene, E. cloacae displays inducible ampC expression. By cloning the ampC gene it was shown that a linked genetic locus, ampR, mediated the induction by beta-lactams. In the...

  20. A method for the detection of antibiotic resistance markers in clinical strains of Escherichia coli using MALDI mass spectrometry.

    Science.gov (United States)

    Hart, Philippa J; Wey, Emmanuel; McHugh, Timothy D; Balakrishnan, Indran; Belgacem, Omar

    2015-04-01

    Matrix-assisted laser-desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most widely used mass spectrometry based approaches for bacterial identification and classification. The relatively simple sample preparation requirements and the speed of analysis which can usually be completed within a few minutes have resulted in the adoption and assimilation of MALDI-TOF MS into the routine diagnostic workflow of Clinical microbiology laboratories worldwide. This study describes the facilitation of bacterial discrimination based on antibiotic resistance markers through the implementation of MALDI-TOF MS. The periplasmic compartment of whole bacterial cells contains several proteins which confer antibiotic resistance in the Enterobacteriaceae. In order to reduce the complexity of the sample to be analysed via MALDI-TOF MS, the periplasm was extracted and subjected to in solution tryptic digestion followed by nano-LC separation. This method, established that peptide sequence biomarkers from several classes of antibiotic resistance proteins could be predicted using protein/peptide database tools such as Mascot. Biomarkers for a CTX-M-1 group extended spectrum β-lactamase, CMY-2 an Amp-C β-lactamase, VIM a metallo-β-lactamase, TEM a β-lactamase and KanR an aminoglycoside modifying enzyme were detected. This allowed for discrimination at a species level and at an almost identical strain level where the only difference between strains was the carriage of a modified antibiotic resistance carrying plasmid. This method also was able to detect some of these biomarkers in clinical strains where multiple resistance mechanisms were present. PMID:25633625

  1. Glucose-lactose diauxie in Escherichia coli.

    Science.gov (United States)

    Loomis, W F; Magasanik, B

    1967-04-01

    Growth of Escherichia coli in medium containing glucose, at a concentration insufficient to support full growth, and containing lactose, is diauxic. A mutation in the gene, CR, which determines catabolite repression specific to the lac operon, was found to relieve glucose-lactose but not glucose-maltose diauxie. Furthermore, a high concentration of lactose was shown to overcome diauxie in a CR(+) strain. Studies on the induction of beta-galactosidase by lactose suggested that glucose inhibits induction by 10(-2)m lactose. Preinduction of the lac operon was found to overcome this effect. The ability of glucose to prevent expression of the lac operon by reducing the internal concentration of inducer as well as by catabolite repression is discussed. PMID:5340309

  2. Whole Genome Epidemiological Typing of Escherichia coli

    DEFF Research Database (Denmark)

    Kaas, Rolf Sommer

    is in general expensive and to some extent unreliable. Next generation sequencing has quickly become a tool widely available and has enabled even smaller laboratories to do whole genome sequencing (WGS). Having the entire genome available provides the opportunity to create the ultimate typing method. This Ph......D thesis attempts to take the first steps toward such a method. In Kaas I all publicly available E. coli genomes sequenced (186) are analyzed. 1,702 core genes were found in all genomes. 3,051 genes were found in 95% of the genomes. The pan genome was found to consist of 16,373 genes. The overall phylogeny...... was inferred from the core genome and also set into context of the Escherichia genus. The variance within each gene cluster was calculated in order to compare the variance between genes and possibly identify typing targets for further study. The variance scores calculated was also used to compare the three...

  3. Prevalence of blaTEM , blaSHV and blaCTX-M genes in clinical isolates of Escherichia coli and Klebsiella pneumoniae from Northeast India

    Directory of Open Access Journals (Sweden)

    Arijit Bora

    2014-01-01

    Full Text Available Aim: This study was carried out to determine the presence of blaTEM , blaSHV and blaCTX-M genes in extended-spectrum β-lactamase (ESBL producing Escherichia coli (E. coli and Klebsiella pneumoniae (K. pneumoniae at a tertiary care referral hospital in Northeast India. Materials and Methods: A total of 270 E. coli and 219 K. pneumoniae isolates were recovered during the period between August 2009 and July 2010. Kirby-Bauer disk diffusion method was performed to determine the antibiotic resistance pattern. Screening and phenotypic confirmatory test for ESBL production were performed using standard disc diffusion methods. Each of the initial ESBL screening test isolate was investigated for the presence of blaTEM , blaSHV and blaCTX-M genes via polymerase chain reaction (PCR using gene-specific primers. Results: Phenotypic confirmatory test able to detect ESBL production in 73.58% of E. coli and 67.24% of K. pneumoniae. However, PCR amplification showed the presence of one or more ESBL genes in each of the initial ESBL screening positive isolate. Among three ESBL genotypes, the most prevalent genotype was found to be blaCTX-M in E. coli (88.67% and blaTEM in K. pneumoniae (77.58% ESBL producing isolates. Majority of ESBL producing isolates possess more than one ESBL genes. Conclusion: This study constituted a primer report on high prevalence of blaTEM and blaCTX-M genes in ESBL producing isolates of E. coli and K. pneumoniae and denotes the need of more extensive studies on these antibiotic genes to determine the magnitude of the problem of antibiotic resistance exiting in this locality.

  4. Escherichia coli in chronic inflammatory bowel diseases: An update on adherent invasive Escherichia coli pathogenicity

    Institute of Scientific and Technical Information of China (English)

    Margarita; Martinez-Medina; Librado; Jesus; Garcia-Gil

    2014-01-01

    Escherichia coli(E. coli), and particularly the adherent invasive E. coli(AIEC) pathotype, has been increasingly implicated in the ethiopathogenesis of Crohn’s disease(CD). E. coli strains with similar pathogenic features to AIEC have been associated with other intestinal disorders such as ulcerative colitis, colorectal cancer, and coeliac disease, but AIEC prevalence in these diseases remains largely unexplored. Since AIEC was described one decade ago, substantial progress has been made in deciphering its mechanisms of pathogenicity. However, the molecular bases that characterize the phenotypic properties of this pathotype are still not well resolved. A review of studies focused on E. coli populations in inflammatory bowel disease(IBD) is presented here and we discuss about the putative role of this species on each IBD subtype. Given the relevance of AIEC in CD pathogenesis, we present the latest research findings concerning AIEC host-microbe interactions and pathogenicity. We also review the existing data regarding the prevalence and abundance of AIEC in CD and its association with other intestinal diseases from humans and animals, in order to discuss the AIEC disease- and hostspecificity. Finally, we highlight the fact that dietarycomponents frequently found in industrialized countries may enhance AIEC colonization in the gut, which merits further investigation and the implementation of preventative measures.

  5. Independence of replisomes in Escherichia coli chromosomalreplication

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-03-13

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

  6. Escherichia coli Pathotypes Occupy Distinct Niches in the Mouse Intestine

    OpenAIRE

    Meador, Jessica P.; Caldwell, Matthew E.; Cohen, Paul S.; Conway, Tyrrell

    2014-01-01

    Since the first step of the infection process is colonization of the host, it is important to understand how Escherichia coli pathogens successfully colonize the intestine. We previously showed that enterohemorrhagic O157:H7 strain E. coli EDL933 colonizes a niche in the streptomycin-treated mouse intestine that is distinct from that of human commensal strains, which explains how E. coli EDL933 overcomes colonization resistance imparted by some, but not all, commensal E. coli strains. Here we...

  7. Genomic Comparative Study of Bovine Mastitis Escherichia coli

    OpenAIRE

    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 i...

  8. Phenotypic detection and occurrence of extended-spectrum beta-lactamases in clinical isolates of Klebsiella pneumoniae and Escherichia coli at a tertiary Hospital in Trinidad & Tobago

    Directory of Open Access Journals (Sweden)

    Patrick E. Akpaka

    2008-12-01

    Full Text Available The incidence and distribution of ESBL producing microorganisms such as E. coli and K. pneumoniae have been demonstrated and varies in different health care facilities and as well as other countries This study was carried out to determine the frequency of occurrence and the antimicrobial susceptibility pattern of ESBL producing E. coli and K. pneumoniae species from clinical isolates at a tertiary hospital in Trinidad & Tobago. Standard microbiological procedures and automated MicroScan System was used to identify, screen for putative ESBL production and determine antimicrobial susceptibility of 1,118 clinical isolates of Enterobacteriaceae species at the microbiology laboratory of the Eric Williams Medical Science Complex, Trinidad & Tobago over a 36 months period. All ESBL producing isolates flagged by the automated system were further confirmed by E-test method. The E-test confirmed a 15.2% ESBL rate among the K. pneumoniae isolates and 9.3% among the E. coli isolates. There was also a 1.8% rate of ESBL production in K. pneumoniae and 0.2% in E. coli isolates from specimens received from community health facilities into the laboratory. Isolates recovered from the intensive care unit of the hospital had 2.1% E. coli and 8.2% K. pneumoniae ESBL producers. Although all ESBL positive isolates were completely susceptible to imipenem and meropenem; and all positive K. pneumoniae isolates were susceptible to amikacin, there was a low susceptibility of ESBL positive E. coli to the aminoglycosides. However, susceptibility of these ESBL producing isolates to the fluoroquinolones varied. There is a high rate of ESBL production among isolates of E. coli and K. pneumoniae at this hospital that is linked to the extensive inappropriate use of third generation cephalosporins in the country. Further molecular studies are needed to characterize the types of these ESBL prevailing in the country.

  9. Metabolic and clinical response to Escherichia coli lipopolysaccharide in layer pullets of different genetic backgrounds supplied with graded dietary L-arginine.

    Science.gov (United States)

    Lieboldt, M A; Frahm, J; Halle, I; Görs, S; Schrader, L; Weigend, S; Preisinger, R; Metges, C C; Breves, G; Dänicke, S

    2016-03-01

    L-arginine (Arg) is an essential amino acid in birds that plays a decisive role in avian protein synthesis and immune response. Effects of graded dietary Arg supply on metabolic and clinical response to Escherichia coli lipopolysaccharide (LPS) were studied over 48 hours after a single intramuscular LPS injection in 18-week-old genetically diverse purebred pullets. LPS induced a genotype-specific fever response within 4 hours post injectionem. Whereas brown genotypes showed an initial hypothermia followed by longer-lasting moderate hyperthermia, white genotypes exhibited a biphasic hyperthermia without initial hypothermia. Furthermore, within 2 hours after LPS injection, sickness behavior characterized by lethargy, anorexia, intensified respiration, and ruffled feathers appeared, persisted for 3 to 5 hours and recovered 12 hours post injectionem. The varying grades of Arg did not alter the examined traits named above, whereas insufficient Arg reduced body growth and increased relative weights of liver and pancreas significantly. At 48 hours post injectionem, increased relative weights of liver and spleen were also found in LPS treated pullets, whereas LPS decreased those of pancreas, bursa, thymus, and cecal tonsils. Moreover, LPS lowered the sum of plasma amino acids and decreased plasma concentrations of Arg, citrulline, glutamate, methionine, ornithine, phenylalanine, proline, tryptophan, and tyrosine, and increased those of aspartate, glutamine, lysine, 1- and 3-methyl-histidine. Elevating concentrations of dietary Arg led to increasing plasma concentrations of Arg, citrulline, ornithine, and 3-methyl-histidine subsequently. As quantitative expression of LPS-induced anorexia, proteolysis, and the following changes in plasma amino acids, pullets showed a significant decrease of feed and nitrogen intake and catabolic metabolism characterized by negative nitrogen balance and body weight loss in the first 24 hours post injectionem. Pullets recovered from the

  10. Pseudosecretion of Escherichia coli chloramphenicol acetyltransferase by Bacillus subtilis.

    OpenAIRE

    Le Grice, S F; Gentz, R; Bannwarth, W; Kocher, H. P.

    1987-01-01

    Bacillus subtilis harboring the vector 25RBSII secrets an Escherichia coli-derived chloramphenicol acetyltransferase into culture supernatants. The secreted enzyme lacks 18 amino acids; these are removed externally rather than during secretion.

  11. Role of recBC nuclease in Escherichia coli transformation.

    OpenAIRE

    Hoekstra, W P; Bergmans, J E; Zuidweg, E.M.

    1980-01-01

    In Escherichia coli transformation with linear donor deoxyribonucleic acid, the recBC pathway is functional, but genetic analysis shows that the recBC nuclease is deleterious to linear deoxyribonucleic acid.

  12. Heat-stable enterotoxins from Escherichia coli P16.

    OpenAIRE

    Burgess, M N; Mullan, N A; Newsome, P.M.

    1980-01-01

    Escherichia coli P16 infant mouse active heat-stable enterotoxin may be fractionated into two distinct active moieties by ion-exchange chromatography, Sephadex G-25 chromatography, and isoelectric focusing.

  13. A DNA structural atlas for Escherichia coli.

    Science.gov (United States)

    Pedersen, A G; Jensen, L J; Brunak, S; Staerfeldt, H H; Ussery, D W

    2000-06-16

    We have performed a computational analysis of DNA structural features in 18 fully sequenced prokaryotic genomes using models for DNA curvature, DNA flexibility, and DNA stability. The structural values that are computed for the Escherichia coli chromosome are significantly different from (and generally more extreme than) that expected from the nucleotide composition. To aid this analysis, we have constructed tools that plot structural measures for all positions in a long DNA sequence (e.g. an entire chromosome) in the form of color-coded wheels (http://www.cbs.dtu. dk/services/GenomeAtlas/). We find that these "structural atlases" are useful for the discovery of interesting features that may then be investigated in more depth using statistical methods. From investigation of the E. coli structural atlas, we discovered a genome-wide trend, where an extended region encompassing the terminus displays a high of level curvature, a low level of flexibility, and a low degree of helix stability. The same situation is found in the distantly related Gram-positive bacterium Bacillus subtilis, suggesting that the phenomenon is biologically relevant. Based on a search for long DNA segments where all the independent structural measures agree, we have found a set of 20 regions with identical and very extreme structural properties. Due to their strong inherent curvature, we suggest that these may function as topological domain boundaries by efficiently organizing plectonemically supercoiled DNA. Interestingly, we find that in practically all the investigated eubacterial and archaeal genomes, there is a trend for promoter DNA being more curved, less flexible, and less stable than DNA in coding regions and in intergenic DNA without promoters. This trend is present regardless of the absolute levels of the structural parameters, and we suggest that this may be related to the requirement for helix unwinding during initiation of transcription, or perhaps to the previously observed

  14. Characterization of multidrug-resistant Escherichia coli by antimicrobial resistance profiles, plasmid replicon typing, and pulsed-field gel electrophoresis

    Science.gov (United States)

    Aim: Plasmid characterization has particular clinical importance because genes encoding significant traits including antimicrobial resistance are frequently carried on plasmids. The objective of this study was to examine the distribution of multidrug resistance (MDR) in Escherichia coli in relation ...

  15. Multicenter evaluation of resistance patterns of Klebsiella pneumoniae, Escherichia coli, Salmonella spp and Shigella spp isolated from clinical specimens in Brazil: RESISTNET surveillance program

    Directory of Open Access Journals (Sweden)

    Carmen Paz Oplustil

    2001-02-01

    Full Text Available Surveillance programs are essential to detect the increase of antimicrobial resistance, and several different programs are being conducted in many countries. The RESISTNET is a surveillance program for bacterial resistance against several antimicrobial agents initiated in 1998 among Latin American countries. In Brazil, several centers were invited to join this surveillance and a total of 11 centers (6 from São Paulo and 5 from other states participated in the study. All results were analyzed using the WHONET program. A total of 894 Escherichia coli, 386 Klebsiella pneumoniae, 70 Shigella spp and 57 Salmonella spp strains were analyzed in this study from April, 1998, to April, 1999. Susceptibility testing was performed by the disk diffusion method using NCCLS 1998 guidelines for several different drugs. For all strains, imipenem was the most effective drug (100% of the strains were susceptible. Klebsiella pneumoniae presented a high resistance rate to ampicillin (96.4%. The rate of probable ESBL producers among K. pneumoniae strains was 36.3%, most of them being isolated from catheters (58.8%. Among all Escherichia coli strains analyzed, the highest resistance rate was found for trimethoprim/sulfamethoxazole (46.9% and the majority of the resistant strains were isolated from urine samples (47.8%. Among Salmonella spp, the resistance rates were low for all antibiotics tested. For Shigella spp strains there was a high resistance to trimethoprim/sulfamethoxazole (80.0%. No resistance to ceftriaxone was observed in these strains. Surveillance of antimicrobial resistance is critical for the successful management of infectious diseases. The results of this survey show significant resistance rates among these bacteria which are responsible for several types of human infections.

  16. The Escherichia coli divisome: born to divide.

    Science.gov (United States)

    Natale, Paolo; Pazos, Manuel; Vicente, Miguel

    2013-12-01

    Septation in Escherichia coli involves complex molecular mechanisms that contribute to the accuracy of bacterial division. The proto-ring, a complex made up by the FtsZ, FtsA and ZipA proteins, forms at the beginning of the process and directs the assembly of the full divisome. Central to this complex is the FtsZ protein, a GTPase able to assemble into a ring-like structure that responds to several modulatory inputs including mechanisms to position the septum at midcell. The connection with the cell wall synthesising machinery stabilizes the constriction of the cytoplasmic membrane. Although a substantial amount of evidence supports this description, many details on how individual divisome elements are structured or how they function are subjected to controversial interpretations. We discuss these discrepancies arising from incomplete data and from technical difficulties imposed by the small size of bacteria. Future work, including more powerful imaging and reconstruction technologies, will help to clarify the missing details on the architecture and function of the bacterial division machinery. PMID:23962168

  17. Completion of DNA replication in Escherichia coli

    Science.gov (United States)

    Wendel, Brian M.; Courcelle, Charmain T.; Courcelle, Justin

    2014-01-01

    The mechanism by which cells recognize and complete replicated regions at their precise doubling point must be remarkably efficient, occurring thousands of times per cell division along the chromosomes of humans. However, this process remains poorly understood. Here we show that, in Escherichia coli, the completion of replication involves an enzymatic system that effectively counts pairs and limits cellular replication to its doubling point by allowing converging replication forks to transiently continue through the doubling point before the excess, over-replicated regions are incised, resected, and joined. Completion requires RecBCD and involves several proteins associated with repairing double-strand breaks including, ExoI, SbcDC, and RecG. However, unlike double-strand break repair, completion occurs independently of homologous recombination and RecA. In some bacterial viruses, the completion mechanism is specifically targeted for inactivation to allow over-replication to occur during lytic replication. The results suggest that a primary cause of genomic instabilities in many double-strand-break-repair mutants arises from an impaired ability to complete replication, independent from DNA damage. PMID:25368150

  18. Expression of Treponema pallidum antigens in Escherichia coli K-12.

    OpenAIRE

    Stamm, L V; Folds, J D; Bassford, P J

    1982-01-01

    A colony bank of recombinant plasmids harboring Treponema pallidum DNA inserts has been established in Escherichia coli K-12. By using an in situ immunoassay, we identified four E. coli clones that expressed T. pallidum antigens. Thus, recombinant DNA technology may provide powerful new tools for studying the pathogenesis of T. pallidum infection.

  19. Antibiotic Resistance Patterns in Enteric and Uropathogenic Strains of Escherichia Coli in Children

    Directory of Open Access Journals (Sweden)

    This paper should be cited as: Sedighi I, Alikhani MY, Nakhaee S, Karami P . [ Antibiotic Resistance Patterns in Enteric and Uropathogenic Strains of Escherichia Coli in Children ]. mlj goums . 201 4 ; 8 ( Suppl 4 : 42 - 48 [Article in Per sian] Sedi ghi, I. (MD

    2014-11-01

    Full Text Available Background and Objective: Escherichia coli is the most common cause of urinary tract infections in children and the leading cause of intra-abdominal infections (peritonitis and abscess followed intestinal injuries. Urinary tract infection, including cystitis and pyelonephritis, is a common childhood infection. E. coli causes more than 90 percent of the community acquired and 50% of hospital acquired urinary tract infections; therefore, the determination of E. coli antibiotic susceptibility is a paramount importance to clinical and epidemiological purposes. Material and Methods: In this cross-sectional study, 50 E. coli strains isolated from urine samples of children less than 7 years of age with urinary tract infections. They were compared for drug susceptibility testing by disc diffusion method with 50 strains of Escherichia coli isolated from stool samples of healthy children with the same age and sex pattern. Results: The actual amount of drug sensitivity of uropathogenic and intestinal Escherichia coli strains to amikacin was 94 and 100%, nitrofurantoin 90 and 88%, gentamicin 66 and 94%, cefixime 56 and 60%, nalidixic acid 38 and 44% and to cotrimoxazole 28 and 32%, respectively. Conclusion: the rate of resistance to gentamicin, Cefixime and nalidixic acid in urinary tract infection isolates were more than intestinal strains. The highest rate of drug resistance in urinary Escherichia coli isolates was associated with cotrimoxazole and the lowest one with amikacin.

  20. Molecular Epidemiology of Escherichia coli Sequence Type 131 and Its H30 and H30-Rx Subclones among Extended-Spectrum-β-Lactamase-Positive and -Negative E. coli Clinical Isolates from the Chicago Region, 2007 to 2010

    OpenAIRE

    Banerjee, Ritu; Robicsek, Ari; Kuskowski, Michael A.; Porter, Stephen; Johnston, Brian D.; Sokurenko, Evgeni; Tchesnokova, Veronika; Lance B Price; Johnson, James R.

    2013-01-01

    We assessed Escherichia coli ST131 and its H30 and H30-Rx subclones for virulence genes, antimicrobial resistance, and extended-spectrum beta-lactamase (ESBL) type. Although both subclones were associated with ESBL production, H30-Rx isolates had higher resistance scores and were associated specifically with CTX-M-15. Three virulence genes (iha, sat, and iutA) were more prevalent among H30 than non-H30 ST131 isolates. Thus, the H30 and H30-Rx subclones are more antimicrobial resistant and hav...

  1. PCR-ELISA detection of Escherichia coli in milk

    OpenAIRE

    Doyle, Sean; Daly, Paul; Collier, T.

    2002-01-01

    Aims: The purpose of this study was to develop a reliable molecular procedure for the detection of Escherichia coli in milk. Methods and Results: Robust and expeditious DNA extraction and PCR techniques were evaluated using Enzyme-Linked Immunosorbent Assay (ELISA) detection of biotin-labelled amplicons to facilitate optimal detection of E. coli DNA. Conclusions: It was found that 5 E. coli colony-forming units (cfu) could be detected per PCR reaction using the PCR-ELISA sys...

  2. A novel IS26 structure is surrounding blaCTX-M genes in different plasmids of German clinical isolates of Escherichia coli

    OpenAIRE

    Cullik, Angela; Pfeifer, Yvonne; Prager, Rita; von Baum, Heike; Witte, Wolfgang

    2010-01-01

    This report focuses on the molecular characterization of 22 extended-spectrum beta-lactamase (ESBL) producing E. coli isolates collected in a German university hospital, during a period of nine months in 2006. Relationship analysis of clinical isolates was done via pulsed-field gel-electrophoresis, mulit-locus sequence typing, plasmid profiling and additionally PCR for blaESBL detection and phylogroups. After conjugal transfer plasmid isolation and subsequent PCR for blaESBL detection and inc...

  3. 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.

  4. Contribution of Escherichia coli Alpha-Hemolysin to Bacterial Virulence and to Intraperitoneal Alterations in Peritonitis

    OpenAIRE

    May, Addison K; Gleason, Thomas G.; Sawyer, Robert G.; Pruett, Timothy L.

    2000-01-01

    Alpha-hemolysin (Hly) is a common exotoxin produced by Escherichia coli that enhances virulence in a number of clinical infections. The addition of hemolysin production to laboratory bacterial strains is known to increase the lethality of E. coli peritonitis. However, the mechanisms involved have not been determined and the contribution of hemolysin to the alterations in the host intraperitoneal environment and the leukocyte response is not known. Utilizing a rat peritonitis model, we show th...

  5. Characterization of Escherichia coli Phylogenetic Groups Associated with Extraintestinal Infections in South Indian Population

    OpenAIRE

    Chakraborty, A.; Saralaya, V; Adhikari, P; Shenoy, S.; Baliga, S.; A Hegde

    2015-01-01

    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 infection, expression of virulence factors, antimicrobial resistance patterns, and clinical outcome. This descriptive study was carried out in a multi-specialty Tertiary Ca...

  6. In vitro inhibition of adhesion of Escherichia coli strains by Xylitol

    OpenAIRE

    Annelisa Farah da Silva; Érika Yoko Suzuki; Aline Siqueira Ferreira; Murilo Gomes Oliveira; Sílvio Silvério da Silva; Nádia Rezende Barbosa Raposo

    2011-01-01

    The present study aimed to evaluate xylitol's antimicrobial and anti-adherence activities on Escherichia coli (ATCC 8739) and on another clinical strain enteropathogenic E. coli (EPEC). In vitro minimum inhibitory concentration (MIC) test and adhesion assays were performed using 0.5, 2.5 and 5.0% xylitol. It was found that xylitol did not have antimicrobial properties on these strains. The scanning electron microscopy (SEM) demonstrated that the slides treated with xylitol had a significant r...

  7. The versatile strategies of Escherichia coli pathotypes: a mini review

    Directory of Open Access Journals (Sweden)

    C. P. Sousa

    2006-01-01

    Full Text Available The widespread species Escherichia coli includes a broad variety of different types, ranging from highly pathogenic strains to avirulent isolates. Few microorganisms are as versatile as E. coli. Pathogenic strains remain a leading cause of severe and persistent infant diarrhea in developing countries. They may be limited to colonization of a mucosal surface or can disseminate throughout the body and have been implicated in urinary tract infection, sepsis/meningitis and gastrointestinal infection. The human gastrointestinal tract is susceptible to diarrheagenic E. coli infections. Escherichia coli have effectively managed to subvert the host cytoskeleton for their own purposes causing substantial diarrheal disease, a major public health problem worldwide. This review deals with the different strategies regarding E. coli as a pathogen and the virulence traits of its pathotypes highlighting the species as a commensal, opportunistic and specialized pathogen.

  8. De novo biosynthesis of Gastrodin in Escherichia coli.

    Science.gov (United States)

    Bai, Yanfen; Yin, Hua; Bi, Huiping; Zhuang, Yibin; Liu, Tao; Ma, Yanhe

    2016-05-01

    Gastrodin, a phenolic glycoside, is the key ingredient of Gastrodia elata, a notable herbal plant that has been used to treat various conditions in oriental countries for centuries. Gastrodin is extensively used clinically for its sedative, hypnotic, anticonvulsive and neuroprotective properties in China. Gastrodin is usually produced by plant extraction or chemical synthesis, which has many disadvantages. Herein, we report unprecedented microbial synthesis of gastrodin via an artificial pathway. A Nocardia carboxylic acid reductase, endogenous alcohol dehydrogenases and a Rhodiola glycosyltransferase UGT73B6 transformed 4-hydroxybenzoic acid, an intermediate of ubiquinone biosynthesis, into gastrodin in Escherichia coli. Pathway genes were overexpressed to enhance metabolic flux toward precursor 4-hydroxybenzyl alcohol. Furthermore, the catalytic properties of the UGT73B6 toward phenolic alcohols were improved through directed evolution. The finally engineered strain produced 545mgl(-1) gastrodin in 48h. This work creates a new route to produce gastrodin, instead of plant extractions and chemical synthesis. PMID:26804288

  9. Infektionsprophylaxe mit Escherichia coli Stamm Nissle 1917 bei Frühgeborenen unter 1500 g

    OpenAIRE

    Blümlein, Ulrike

    2012-01-01

    The main question of this study was, if prophylactic treatment with Escherichia coli strain Nissle 1917 helps to prevent infection in VLBW infants. Because of different limitations of this pilot study this issue can not be entirely clarified. The study illustrates the influence of Escherichia coli strain Nissle 1917 (EcN) on the clinical course of VLBW infants: The treatment with EcN was indifferent for the weight increase between the 10th and 30th day of life. One can not rule out the possib...

  10. Role of verocytotoxigenic Escherichia coli in the swine production chain

    Directory of Open Access Journals (Sweden)

    Laura Ercoli

    2015-06-01

    Full Text Available Shiga toxin-producing Escherichia coli (STEC can cause severe clinical diseases in humans, such as haemorrhagic colitis (HC and haemolytic-uremic syndrome (HUS. Although ruminants, primarily cattle, have been suggested as typical reservoirs of STEC, many food products of other origins, including pork products, have been confirmed as vehicles for STEC transmission. Only in rare cases, pork consumption is associated with severe clinical symptoms caused by high pathogenic STEC strains. However, in these outbreaks, it is unknown whether the contamination of food products occurs during swine processing or via cross-contamination from foodstuffs of different sources. In swine, STEC plays an important role in the pathogenesis of oedema disease. In particular a Shiga toxin subtype, named stx2e, it is considered as a key factor involved in the damage of swine endothelial cells. On the contrary, stx2e-producing Escherichia coli has rarely been isolated in humans, and usually only from asymptomatic carriers or from patients with mild symptoms, such as uncomplicated diarrhoea. In fact, the presence of gene stx2e, encoding for stx2e, has rarely been reported in STEC strains that cause HUS. Moreover, stx2e-producing STEC isolated from humans and pigs were found to differ in serogroup, their virulence profile and interaction with intestinal epithelial cells. Because of the limited epidemiologic data of STEC in swine and the increasing role of non-O157 STEC in human illnesses, the relationship between swine STEC and human disease needs to be further investigated.

  11. 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...... and kidney cultures. Further, isolates with the same gene profile also yielded similar bacterial counts in urine, bladder and kidneys. This study showed a clonal link between E. coli from meat and humans, providing solid evidence that UTI is zoonosis. The close relationship between community...

  12. Expression of ESBL, MBL and AmpC β lactamases by extra intestinal Escherichia coli isolates: correlation with treatment and clinical outcome

    Directory of Open Access Journals (Sweden)

    Arindam Chakraborty

    2013-12-01

    Full Text Available Objective:We investigated the expression of Extended Spectrum β-Lactamases (ESBLs, AmpC β lactamases and Carbapenemases in extraintestinal pathogenic Escherichia coli (ExPEC isolates and correlated with treatment and outcome of the patients. Methods: Three hundred ExPEC infected patients were included in the study. Demographic data, antibiogram, treatment and outcome were collected. Production of ESBLs was detected by combination disk method; AmpC was detected by AmpC disk test. Carbapenemase production was detected by disk diffusion and confirmed by modified Hodge test. Identification of metallo- β-lactamase (MBL activity was performed by the arbapenem-EDTA combined disk method and MBL E-test. Results:Out of 300 E. coli isolates, 212 (71% were ESBL producers. AmpC β lactamase production was seen in 95 (32% isolates; 16 (17% isolates were pure AmpC producers whereas 79 (83% were ESBL co-producers. Twenty nine (9.5% isolates were carbapenemase producers of which 15 (5% were MBL producers. For treatment, most widely prescribed antibiotics were β-lactam+β-lactamase inhibitor combinations (39%. Sixty seven percent patients improved; relapse/ re-infection was seen in 18% of patients and 11% patients expired. Increased mortality was seen in patients with blood stream infection and more number of relapses was seen in urinary tract infection. Conclusion:ExPEC producing ESBL or AmpC along with carbapenemases are particularly challenging for clinicians and are a major threat worldwide. Early use of appropriate antibiotics like β-lactam+β-lactamase inhibitor combinations will probably reduce complications in these patients. J Microbiol Infect Dis 2013;3(4: 150-156

  13. Aerobactin-mediated iron uptake by Escherichia coli isolates from human extraintestinal infections.

    OpenAIRE

    Carbonetti, N H; Boonchai, S; Parry, S H; Väisänen-Rhen, V; Korhonen, T K; Williams, P H

    1986-01-01

    A total of 516 strains of Escherichia coli were screened for the presence and expression of the aerobactin iron uptake system. The incidence was markedly higher among clinical isolates from patients with septicemia (68.8%), pyelonephritis (74.6%), and symptomatic (59.8%) and asymptomatic (63.2%) lower urinary tract infections than among normal human fecal isolates (34.3%).

  14. Ciprofloxacin and probiotic Escherichia coli Nissle add-on treatment in active ulcerative colitis

    DEFF Research Database (Denmark)

    Petersen, Andreas Munk; Mirsepasi, Hengameh; Halkjær, Sofie Ingdam;

    2014-01-01

    BACKGROUND AND AIM: Ulcerative colitis (UC) is a chronic inflammatory bowel disease. The probiotic bacterium Escherichia coli Nissle 1917 (EcN) has been used to maintain and induce clinical remission in UC. Our aim was to test the effect of Ciprofloxacin and/or orally administered EcN as add-on to...

  15. Molecular hazard identification of non-O157 Shiga toxin-producing Escherichia coli (STEC)

    NARCIS (Netherlands)

    Franz, E.; Hoek, van Angela H.A.M.; Wuite, Mark; Wal, van der F.J.; Boer, de A.G.; Bouw, E.L.; Aarts, Henk J.M.

    2015-01-01

    The complexity regarding Shiga toxin-producing Escherichia coli (STEC) in food safety enforcement as well as clinical care primarily relates to the current inability of an accurate risk assessment of individual strains due to the large variety in serotype and genetic content associated with (severe)

  16. 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

  17. An Evaluation of Common Cleaning Methods for the Removal of a Clinical Isolate of Escherichia coli in Personal Hydration System Water Reservoirs.

    Science.gov (United States)

    Helmus, Stephanie; Blythe, Jauchia; Guevara, Peter; Washington, Michael A

    2016-01-01

    Waterborne infection is an important cause of morbidity and mortality throughout the world. Personal hydration packs have been used by military personnel since the Gulf War and are now a common issue item. Since military personnel tend to operate under austere conditions and may use a variety of water sources, preventing the acquisition of waterborne infections is extremely important. Further, since hydration pack water reservoir replacements may not be available during combat operations, the development of a reliable cleaning protocol for use in the field is essential. Several methods for cleaning have been described. In the current study, three common cleaning methodologies-bleach treatment, baking soda treatment, and proprietary CAMELBAK Cleaning Tabs™-were evaluated for the ability to remove Escherichia coli contamination from hydration pack water reservoirs. The study results suggest that the use of bleach and proprietary CAMELBAK tablets should be encouraged since they both operate by releasing bactericidal chlorine compounds into solution, which is more effective at reducing post-treatment bacterial burden. It should be noted that no method was 100% effective at completely eliminating bacteria from the reservoirs and that mechanical cleaning was not attempted. PMID:27450612

  18. Survey on O157:H7 enterohemorrhagic Escherichia coli (EHEC in cattle in Golestan province, Iran.

    Directory of Open Access Journals (Sweden)

    Alireza Koochakzadeh

    2014-08-01

    Full Text Available A diverse group of Escherichia coli are known as enterohemorrhagic Escherichia coli (EHEC including O157:H7 and non-O157 EHEC. Enterohemorrhagic strains are related to sever clinical conditions in humans including hemorrhagic colitis and hemolytic uremic syndrome, and most of the recorded outbreaks occurred due to O157: H7 E. coli. The aim of the present study was to investigate the presence of O157:H7 E. coli among healthy cattle in Golestan province.Fecal samples were collected from 180 clinically healthy cattle in Golestan province. After primary enrichment, samples were streaked on sorbitol MacConkey agar supplemented with cefixime and potassium tellurite (CT-SMAC. Non-sorbitol fermenting (NSF Escherichia coli isolates were subjected to serotyping using commercial O157 antisera and rfb O157 gene PCR. Isolates were additionally tested for major virulence factors of EHEC including stx1, stx2, eae and ehly by multiplex-PCR.Eighteen NSF isolates were recovered from CT-SMAC confirmed as E. coli in biochemical tests. None of the obtained isolates belonged to O157 serogroup. Overall, two isolates harbored the tested virulence genes; one isolate possessed stx2 and ehly, and the other one carried stx2, eae and ehly.The results of this study indicated that cattle in Golestan province could be the reservoir for non-O157 EHEC.

  19. Comparison of eight different agars for the recovery of clinically relevant non-O157 Shiga toxin-producing Escherichia coli from baby spinach, cilantro, alfalfa sprouts and raw milk.

    Science.gov (United States)

    Kase, Julie A; Maounounen-Laasri, Anna; Son, Insook; Lin, Andrew; Hammack, Thomas S

    2015-04-01

    The FDA Bacteriological Analytical Manual (BAM) Chapter 4a recommends several agars for isolating non-O157 Shiga toxin-producing Escherichia coli (STEC); not all have been thoroughly tested for recovering STECs from food. Using E. coli strains representing ten clinically relevant O serogroups (O26, O45, O91, O103, O104, O111, O113, O121, O128, O145) in artificially-contaminated fresh produce--bagged baby spinach, alfalfa sprouts, cilantro, and raw milk--we evaluated the performance of 8 different agars. Performance was highly dependent upon strain used and the presence of inhibitors, but not necessarily dependent on food matrix. Tellurite resistant-negative strains, O91:-, O103:H6, O104:H21, O113:H21, and O128, grew poorly on CHROMagar STEC, Rainbow agar O157, and a modified Rainbow O157 (mRB) agar. Although adding washed sheep's blood to CHROMagar STEC and mRB agars improved overall performance; however, this also reversed the inhibition of non-target bacteria provided by original formulations. Variable colony coloration made selecting colonies from Rainbow agar O157 and mRB agars difficult. Study results support a strategy using inclusive agars (e.g. L-EMB, SHIBAM) in combination with selective agars (R & F E. coli O157:H7, CHROMagar STEC) to allow for recovery of the most STECs while increasing the probability of recovering STEC in high bacterial count matrices. PMID:25475297

  20. Evaluation of a Method Using Three Genomic Guided Escherichia coli Markers for Phylogenetic Typing of E. coli Isolates of Various Genetic Backgrounds

    OpenAIRE

    Hamamoto, Kouta; Ueda, Shuhei; Yamamoto, Yoshimasa; Hirai, Itaru

    2015-01-01

    Genotyping and characterization of bacterial isolates are essential steps in the identification and control of antibiotic-resistant bacterial infections. Recently, one novel genotyping method using three genomic guided Escherichia coli markers (GIG-EM), dinG, tonB, and dipeptide permease (DPP), was reported. Because GIG-EM has not been fully evaluated using clinical isolates, we assessed this typing method with 72 E. coli collection of reference (ECOR) environmental E. coli reference strains ...

  1. Fungal β-1,3-Glucan Increases Ofloxacin Tolerance of Escherichia coli in a Polymicrobial E. coli/Candida albicans Biofilm

    OpenAIRE

    De Brucker, Katrijn; Tan, Yulong; Vints, Katlijn; De Cremer, Kaat; Braem, Annabel; Verstraeten, Natalie; Michiels, Jan; Vleugels, Jef; Bruno P.A. Cammue; Thevissen, Karin

    2015-01-01

    In the past, biofilm-related research has focused mainly on axenic biofilms. However, in nature, biofilms are often composed of multiple species, and the resulting polymicrobial interactions influence industrially and clinically relevant outcomes such as performance and drug resistance. In this study, we show that Escherichia coli does not affect Candida albicans tolerance to amphotericin or caspofungin in an E. coli/C. albicans biofilm. In contrast, ofloxacin tolerance of E. coli is signific...

  2. Outbreaks of virulent diarrheagenic Escherichia coli - are we in control?

    Directory of Open Access Journals (Sweden)

    Werber Dirk

    2012-02-01

    Full Text Available Abstract Shiga toxin-producing Escherichia coli (STEC are the most virulent diarrheagenic E. coli known to date. They can be spread with alarming ease via food as exemplified by a large sprout-borne outbreak of STEC O104:H4 in 2011 that was centered in northern Germany and affected several countries. Effective control of such outbreaks is an important public health task and necessitates early outbreak detection, fast identification of the outbreak vehicle and immediate removal of the suspected food from the market, flanked by consumer advice and measures to prevent secondary spread. In our view, opportunities to improve control of STEC outbreaks lie in early clinical suspicion for STEC infection, timely diagnosis of all STEC at the serotype-level and integrating molecular subtyping information into surveillance systems. Furthermore, conducting analytical studies that supplement patients' imperfect food history recall and performing, as an investigative element, product tracebacks, are pivotal but underutilized tools for successful epidemiologic identification of the suspected vehicle in foodborne outbreaks. As a corollary, these tools are amenable to tailor microbiological testing of suspected food. Please see related article: http://www.biomedcentral.com/1741-7015/10/12

  3. Subversion of Host Innate Immunity by Uropathogenic Escherichia coli.

    Science.gov (United States)

    Olson, Patrick D; Hunstad, David A

    2016-01-01

    Uropathogenic Escherichia coli (UPEC) cause the majority of community-onset urinary tract infections (UTI) and represent a major etiologic agent of healthcare-associated UTI. Introduction of UPEC into the mammalian urinary tract evokes a well-described inflammatory response, comprising pro-inflammatory cytokines and chemokines as well as cellular elements (neutrophils and macrophages). In human UTI, this inflammatory response contributes to symptomatology and provides means for diagnosis by standard clinical testing. Early in acute cystitis, as demonstrated in murine models, UPEC gains access to an intracellular niche that protects a population of replicating bacteria from arriving phagocytes. To ensure the establishment of this protected niche, UPEC employ multiple strategies to attenuate and delay the initiation of host inflammatory components, including epithelial secretion of chemoattractants. Recent work has also revealed novel mechanisms by which UPEC blunts neutrophil migration across infected uroepithelium. Taken together, these attributes distinguish UPEC from commensal and nonpathogenic E. coli strains. This review highlights the unique immune evasion and suppression strategies of this bacterial pathogen and offers directions for further study; molecular understanding of these mechanisms will inform the development of adjunctive, anti-virulence therapeutics for UTI. PMID:26742078

  4. Association between antimicrobial consumption and resistance in Escherichia coli.

    Science.gov (United States)

    Bergman, Miika; Nyberg, Solja T; Huovinen, Pentti; Paakkari, Pirkko; Hakanen, Antti J

    2009-03-01

    During a 9-year study period from 1997 through 2005, the association between antimicrobial resistance rates in Escherichia coli and outpatient antimicrobial consumption was investigated in 20 hospital districts in Finland. A total of 754,293 E. coli isolates, mainly from urine samples, were tested for antimicrobial resistance in 26 clinical microbiology laboratories. The following antimicrobials were studied: ampicillin, amoxicillin-clavulanate, cephalosporins, fluoroquinolones, trimethoprim, trimethoprim-sulfamethoxazole, pivmecillinam, and nitrofurantoin. We applied a protocol used in earlier studies in which the level of antimicrobial consumption over 1 year was compared with the level of resistance in the next year. Statistically significant associations were found for nitrofurantoin use versus nitrofurantoin resistance (P < 0.0001), cephalosporin use versus nitrofurantoin resistance (P = 0.0293), amoxicillin use versus fluoroquinolone resistance (P = 0.0031), and fluoroquinolone use versus ampicillin resistance (P = 0.0046). Interestingly, we found only a few associations between resistance and antimicrobial consumption. The majority of the associations studied were not significant, including the association between fluoroquinolone use and fluoroquinolone resistance. PMID:19104012

  5. Outbreaks of virulent diarrheagenic Escherichia coli - are we in control?

    OpenAIRE

    Werber Dirk; Krause Gérard; Frank Christina; Fruth Angelika; Flieger Antje; Mielke Martin; Schaade Lars; Stark Klaus

    2012-01-01

    Abstract Shiga toxin-producing Escherichia coli (STEC) are the most virulent diarrheagenic E. coli known to date. They can be spread with alarming ease via food as exemplified by a large sprout-borne outbreak of STEC O104:H4 in 2011 that was centered in northern Germany and affected several countries. Effective control of such outbreaks is an important public health task and necessitates early outbreak detection, fast identification of the outbreak vehicle and immediate removal of the suspect...

  6. Outbreaks of virulent diarrheagenic Escherichia coli - are we in control?

    OpenAIRE

    Werber, Dirk; Krause, Gérard; Frank, Christina; Fruth, Angelika; Mielke, Martin; Schaade, Lars; Stark, Klaus

    2012-01-01

    Shiga toxin-producing Escherichia coli (STEC) are the most virulent diarrheagenic E. coli known to date. They can be spread with alarming ease via food as exemplified by a large sprout-borne outbreak of STEC O104:H4 in 2011 that was centered in northern Germany and affected several countries. Effective control of such outbreaks is an important public health task and necessitates early outbreak detection, fast identification of the outbreak vehicle and immediate removal of the suspected fo...

  7. Fundamental study of recombination and recombineering in Escherichia coli

    OpenAIRE

    Sun, Xiaohang; Huang, Yang

    2008-01-01

    Recombination and recombineering systems have been used in Escherichia coli to recombinant DNA sequences. With endonuclease and DNA lipase the bacterial plasmid and target DNA fragment can bind together and recombinant for a new DNA sequences. Red Proteins have been used in recombineering system to perform the function as the enzymes in recombination system, and faster and easier than the other way of recombinant new DNA sequences in E.coli. In this report we get to know the pr...

  8. 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......-forming potential of E. coli. Finally, we demonstrated that Ag43-mediated cell aggregation confers significant protection against hydrogen peroxide killing....

  9. Escherichia coli and Community-acquired Gastroenteritis, Melbourne, Australia

    OpenAIRE

    Robins-Browne, Roy M.; Bordun, Anne-Marie; Tauschek, Marija; Bennett-Wood, Vicki R.; Russell, Jacinta; Oppedisano, Frances; Lister, Nicole A.; Bettelheim, Karl A.; Fairley, Christopher K.; Sinclair, Martha I; Hellard, Margaret E

    2004-01-01

    As part of a study to determine the effects of water filtration on the incidence of community-acquired gastroenteritis in Melbourne, Australia, we examined fecal samples from patients with gastroenteritis and asymptomatic persons for diarrheagenic strains of Escherichia coli. Atypical strains of enteropathogenic E. coli (EPEC) were the most frequently identified pathogens of all bacterial, viral, and parasitic agents in patients with gastroenteritis. Moreover, atypical EPEC were more common i...

  10. Recombinant Production of Human Interleukin 6 in Escherichia coli

    OpenAIRE

    Henrik Nausch; Jana Huckauf; Roswitha Koslowski; Udo Meyer; Inge Broer; Heike Mikschofsky

    2013-01-01

    In this study, we compared basic expression approaches for the efficient expression of bioactive recombinant human interleukin-6 (IL6), as an example for a difficult-to-express protein. We tested these approaches in a laboratory scale in order to pioneer the commercial production of this protein in Escherichia coli (E. coli). Among the various strategies, which were tested under Research and Development (R&D) conditions, aggregation-prone IL6 was solubilized most effectively by co-expressing ...

  11. Survival of Escherichia coli and Salmonella spp. in estuarine environments.

    OpenAIRE

    Rhodes, M W; Kator, H.

    1988-01-01

    Survival of Escherichia coli and Salmonella spp. in estuarine waters was compared over a variety of seasonal temperatures during in situ exposure in diffusion chambers. Sublethal stress was measured by both selective-versus-resuscitative enumeration procedures and an electrochemical detection method. E. coli and Salmonella spp. test suspensions, prepared to minimize sublethal injury, were exposed in a shallow tidal creek and at a site 7.1 km further downriver. Bacterial die-off and sublethal ...

  12. Role of granulocytes and monocytes in experimental Escherichia coli endocarditis.

    OpenAIRE

    Meddens, M J; Thompson, J.; Bauer, W C; van Furth, R

    1984-01-01

    The role of granulocytes and monocytes during the induction and course of Escherichia coli endocarditis was investigated in rabbits by selectively depleting monocytes from the circulation with the drug VP16-213 and granulocytes and monocytes with nitrogen mustard. For induction, the number of E. coli needed to infect the vegetations in 50% of the rabbits was significantly lower in rabbits with combined granulocytopenia and monocytopenia than in those with selective monocytopenia or in control...

  13. 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...... general understanding of redox and energy metabolism and should help in developing metabolic engineering strategies in E. coli....

  14. Dissecting the roles of Escherichia coli hydrogenases in biohydrogen production

    OpenAIRE

    Redwood, MD; Mikheenko, IP; Sargent, F.; Macaskie, LE

    2008-01-01

    Escherichia coli can perform at least two modes of anaerobic hydrogen metabolism and expresses at least two types of hydrogenase activity. Respiratory hydrogen oxidation is catalysed by two ‘uptake’ hydrogenase isoenzymes, hydrogenase -1 and -2 (Hyd-1 and -2), and fermentative hydrogen production is catalysed by Hyd-3. Harnessing and enhancing the metabolic capability of E. coli to perform anaerobic mixed-acid fermentation is therefore an attractive approach for bio-hydrogen production ...

  15. Molecular detection and antimicrobial resistance of diarrheagenic Escherichia coli strains isolated from diarrheal cases

    International Nuclear Information System (INIS)

    Objective was to identify and classify Iranian isolates of diarrheagenic Escherichia coli (E. coli) on the basis of presence of virulence genes and to determine antibiotic susceptibility of isolated strains. The current cross-sectional study was conducted in 2005 at the Pasteur Institute, Tehran, Iran. One hundred and ninety-three diarrheagenic E. coli isolated from diarrheal patients in different regions of Iran were included in current study. Virulence factors genees for diarrheagenic E. coli were detected by polymerase chain reaction. Of the 193 diarrheagenic E. coli detected by PCR, 86(44.5%) were Shiga toxin-producing E. coli (STEC), 74 (38.4%) enteropathogenic E. coli (EPEC), 19 (9.8%) enteroaggregative E. coli and 14 (7.3%) enterotoxigenic E. coli isolates. Susceptibility to 12 clinically important antimicrobial agents was determined for 193 strains of diarrhheagenic E. coli. A high incidence of resistance to tetracycline (63%), ampicillin (62%), streptomycin (56%), amoxicillin/clavulanic acid (44.5%), trimetoprim/sulphamethoxazole (39.5%) and cephalothin (37%) was observed. The STEC and EPEC strains with high resistance to tetracycline and ampicillin but highly susceptible to quinolones are among the most important causative agent of diarrhea in Iran. This study suggests that antimicrobial resistance is wide spread among E. coli strains colonizing Iranian patients. Guidelines for appropriate use of antibiotics in developing countries require updating. (author)

  16. Cervical celullitis in broiler chickens for Escherichia coli/ Celulite cervical em frangos de corte causada por Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ivens Gomes Guimarães

    2002-05-01

    Full Text Available In this paper was report the isolation of Escherichia coli in broiler chickens with cellulitis in the cervical region. It was carried through the isolation of E. coli of the lesion of cellulitis from broilers and carried through histopathological examination of skin that had characterized the lesion. Focal ulcerations of epidermis, fibrin in dermis and difuse infiltrated by lymphocytes and heterophils on subcutaneous tissues.Neste trabalho, relata-se o isolamento de Escherichia coli em frangos de corte apresentando lesão de celulite na região cervical. Foi realizado o isolamento de E. coli da lesão de celulite e realizado exames histopatológicos que caracterizaram a lesão. Na epiderme foram verificadas lesões ulcerativas, presença de fibrina na derme e infiltração difusa de linfócitos e heterófilos no tecido subcutâneo.

  17. Probiotic Escherichia coli Nissle 1917 and commensal E. coli K12 differentially affect the inflammasome in intestinal epithelial cells

    OpenAIRE

    Becker, Helen M; Apladas, Aretussa; Scharl, Michael; Fried, Michael; Rogler, Gerhard

    2014-01-01

    BACKGROUND: The probiotic bacterial strain Escherichia coli Nissle 1917 (EcN) is used for the treatment of ulcerative colitis (UC), diarrhea and constipation. Its beneficial effects in the treatment of UC have been demonstrated in several controlled clinical studies; however, the mechanism of action on the cellular level is still not completely clear. The intracellular pattern recognition receptor NLRP3 is expressed in intestinal epithelial cells (IEC), activates caspase-1 within the inflamma...

  18. Inactivation of Escherichia Coli in Orange Juice Using Ozone

    OpenAIRE

    Patil, Sonal; Bourke, Paula; Frias, Jesus Maria; Tiwari, Brijesh; Cullen, Patrick

    2009-01-01

    This research investigated the efficacy of gaseous ozone for the inactivation of Escherichia coli ATCC 25922 and NCTC 12900 strains in orange juice. Orange juice inoculated with E. coli (106 CFU mL-1) as a challenge microorganism was treated with ozone at 75-78µg mL-1 for different time periods (0-18 min). The efficacy of ozone for inactivation of both strains of E. coli was evaluated as a function of different juice types: model orange juice, fresh unfiltered juice, juice without pulp, and j...

  19. 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.

  20. Protein abundance profiling of the Escherichia coli cytosol

    DEFF Research Database (Denmark)

    Ishihama, Y.; Schmidt, T.; Rappsilber, J.;

    2008-01-01

    sample. Using a combination of LC-MS/MS approaches with protein and peptide fractionation steps we identified 1103 proteins from the cytosolic fraction of the Escherichia coli strain MC4100. A measure of abundance is presented for each of the identified proteins, based on the recently developed em...... between protein and mRNA abundance in E. coli cells. Conclusion: Abundance measurements for more than 1000 E. coli proteins presented in this work represent the most complete study of protein abundance in a bacterial cell so far. We show significant associations between the abundance of a protein and its...

  1. YeeO from Escherichia coli exports flavins.

    Science.gov (United States)

    McAnulty, Michael J; Wood, Thomas K

    2014-01-01

    Multidrug and toxic compound extrusion (MATE) proteins help maintain cellular homeostasis by secreting metabolic wastes. Flavins may occur as cellular waste products, with their production and secretion providing potential benefit for industrial applications related to biofuel cells. Here we find that MATE protein YeeO from Escherichia coli exports both flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD). Significant amounts of flavins were trapped intracellularly when YeeO was produced indicating transport limits secretion of flavins. Wild-type E. coli secreted 3 flavins (riboflavin, FMN, and FAD), so E. coli likely produces additional flavin transporters. PMID:25482085

  2. An integrated database to support research on Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Baehr, A.; Dunham, G.; Matsuda, Hideo; Michaels, G.; Taylor, R.; Overbeek, R.; Rudd, K.E. [National Inst. of Mental Health, Bethesda, MD (United States); Ginsburg, A.; Joerg, D.; Kazic, T. [Washington Univ., St. Louis, MO (United States). Dept. of Genetics; Hagstrom, R.; Zawada, D. [Argonne National Lab., IL (United States); Smith, C.; Yoshida, Kaoru [Lawrence Berkeley Lab., CA (United States)

    1992-01-01

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

  3. The clinical-grade 42-kilodalton fragment of merozoite surface protein 1 of Plasmodium falciparum strain FVO expressed in Escherichia coli protects Aotus nancymai against challenge with homologous erythrocytic-stage parasites.

    Science.gov (United States)

    Darko, Christian A; Angov, Evelina; Collins, William E; Bergmann-Leitner, Elke S; Girouard, Autumn S; Hitt, Stacy L; McBride, Jana S; Diggs, Carter L; Holder, Anthony A; Long, Carole A; Barnwell, John W; Lyon, Jeffrey A

    2005-01-01

    A 42-kDa fragment from the C terminus of major merozoite surface protein 1 (MSP1) is among the leading malaria vaccine candidates that target infection by asexual erythrocytic-stage malaria parasites. The MSP1(42) gene fragment from the Vietnam-Oak Knoll (FVO) strain of Plasmodium falciparum was expressed as a soluble protein in Escherichia coli and purified according to good manufacturing practices. This clinical-grade recombinant protein retained some important elements of correct structure, as it was reactive with several functional, conformation-dependent monoclonal antibodies raised against P. falciparum malaria parasites, it induced antibodies (Abs) that were reactive to parasites in immunofluorescent Ab tests, and it induced strong growth and invasion inhibitory antisera in New Zealand White rabbits. The antigen quality was further evaluated by vaccinating Aotus nancymai monkeys and challenging them with homologous P. falciparum FVO erythrocytic-stage malaria parasites. The trial included two control groups, one vaccinated with the sexual-stage-specific antigen of Plasmodium vivax, Pvs25, as a negative control, and the other vaccinated with baculovirus-expressed MSP1(42) (FVO) as a positive control. Enzyme-linked immunosorbent assay (ELISA) Ab titers induced by E. coli MSP1(42) were significantly higher than those induced by the baculovirus-expressed antigen. None of the six monkeys that were vaccinated with the E. coli MSP1(42) antigen required treatment for uncontrolled parasitemia, but two required treatment for anemia. Protective immunity in these monkeys correlated with the ELISA Ab titer against the p19 fragment and the epidermal growth factor (EGF)-like domain 2 fragment of MSP1(42), but not the MSP1(42) protein itself or the EGF-like domain 1 fragment. Soluble MSP1(42) (FVO) expressed in E. coli offers excellent promise as a component of a vaccine against erythrocytic-stage falciparum malaria. PMID:15618165

  4. Molecular Characterization of Diarrheagenic Escherichia coli from Libya

    Science.gov (United States)

    Ali, Mostafa Mohamed M.; Mohamed, Zienat Kamel; Klena, John D.; Ahmed, Salwa Fouad; Moussa, Tarek A. A.; Ghenghesh, Khalifa Sifaw

    2012-01-01

    Diarrheagenic Escherichia coli (DEC) are important enteric pathogens that cause a wide variety of gastrointestinal diseases, particularly in children. Escherichia coli isolates cultured from 243 diarrheal stool samples obtained from Libyan children and 50 water samples were screened by polymerase chain reaction (PCR) for genes characteristic of enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohemorrhagic E. coli (EHEC), and enteroinvasive E. coli (EIEC). The DEC were detected in 21 (8.6%) children with diarrhea; 10 (4.1%) cases were identified as EAEC, 3 (1.2%) as EPEC, and 8 (3.3%) were ETEC; EHEC, and EIEC were not detected. All DEC were grouped phylogenetically by PCR with the majority (> 70%) identified as phylogenetic groups A and B1. The EAEC isolates were also tested for eight genes associated with virulence using PCR. Multi-virulence (≥ 3 virulence factors) was found in 50% of EAEC isolates. Isolated EAEC possessed different virulence traits and belonged to different phylogenetic groups indicating their heterogeneity. PMID:22556089

  5. Recent Sensitivity Pattern of Escherichia Coli in Urinary Tract Infection

    Directory of Open Access Journals (Sweden)

    R Nalini

    2014-06-01

    Full Text Available The objective of the study is to assess the recent sensitivity pattern of Escherichia coli in Urinary tract infection (UTI.Widespread use of antibiotics has led to the emergence of resistant microorganisms. As the antibiotic sensitivity patterns of the microorganisms are frequently changing, this retrospective analysis was designed to assess the recent antibiotic sensitivity pattern of Escherichia coli (E.coli in urinary tract infection among the human population. Details of 412 urine culture positive reports for E.coli and their antibiotic sensitivity pattern pertaining to the study period of 12months from June 2012 to May 2013 were collected from Central Microbiology Laboratory of Tirunelveli Medical College and the results were statistically analysed. The antibiotics tested for sensitivity were Amikacin, Gentamycin, Ciprofloxacin, Cotrimoxazole, Nitrofurantoin, Ceftazidime, Ceftriaxone and Cefotaxime. The sensitivity pattern of E.coli to antibiotics in UTI were Nitrofurantoin (85.19%, Amikacin (66.50%, Co-trimoxazole(31.31%, Gentamycin (26.90%, Ceftazidime (26.69% ,Ciprofloxacin (22.57%, Cefotaxime (22.30%, Ceftriaxone (17.47%. The study highlighted the re-emergence of E. coli sensitive to Nitrofurantoin and marked resistance of E.coli to Aminoglycoside and third generation Cephalosporins.

  6. Carbon and energy metabolism of atp mutants of Escherichia coli

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Michelsen, Ole

    1992-01-01

    The membrane-bound H+-ATPase plays a key role in free-energy transduction of biological systems. We report how the carbon and energy metabolism of Escherichia coli changes in response to deletion of the atp operon that encodes this enzyme. Compared with the isogenic wild-type strain, the growth...

  7. Genetic Basis of Minicell Formation in Escherichia coli K-12

    OpenAIRE

    1984-01-01

    Hfr- and P1-mediated genetic transfer experiments failed to confirm the presence of a " minA " gene in Escherichia coli K-12, leading to the conclusion that mutation at a single locus, the minB locus, is sufficient to cause minicell production in this species.

  8. Antibiotic treatment of verocytotoxin-producing Escherichia coli (VTEC) infection

    DEFF Research Database (Denmark)

    Agger, Morten; Scheutz, Flemming; Villumsen, Steen; Mølbak, Kåre; Petersen, Andreas Munk

    2015-01-01

    OBJECTIVES: A consensus has existed on not to treat verocytotoxin-producing Escherichia coli (VTEC)-infected individuals with antibiotics because of possible subsequent increased risk of developing haemolytic uraemic syndrome (HUS). The aim of this systematic review is to clarify the risk...

  9. Escherichia coli. A sanitary methodology for faecal water pollution tests

    International Nuclear Information System (INIS)

    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

  10. 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...

  11. Chromosomal replication incompatibility in Dam methyltransferase deficient Escherichia coli cells

    DEFF Research Database (Denmark)

    Freiesleben, Ulrik Von

    1996-01-01

    Dam methyltransferase deficient Escherichia coli cells containing minichromosomes were constructed. Free plasmid DNA could not be detected in these cells and the minichromosomes were found to be integrated in multiple copies in the origin of replication (oriC) region of the host chromosome. The...

  12. 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...

  13. Multidrug-Resistant Escherichia coli in Bovine Animals, Europe.

    Science.gov (United States)

    Brennan, Evan; Martins, Marta; McCusker, Matthew P; Wang, Juan; Alves, Bruno Martins; Hurley, Daniel; El Garch, Farid; Woehrlé, Frédérique; Miossec, Christine; McGrath, Leisha; Srikumar, Shabarinath; Wall, Patrick; Fanning, Séamus

    2016-09-01

    Of 150 Escherichia coli strains we cultured from specimens taken from cattle in Europe, 3 had elevated MICs against colistin. We assessed all 3 strains for the presence of the plasmid-mediated mcr-1 gene and identified 1 isolate as mcr-1-positive and co-resistant to β-lactam, florfenicol, and fluoroquinolone antimicrobial compounds. PMID:27533105

  14. Differential expression of the Escherichia coli autoaggregation factor antigen 43

    DEFF Research Database (Denmark)

    Schembri, Mark; Hjerrild, Louise; Gjermansen, Morten; Klemm, Per

    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...

  15. 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...

  16. 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...

  17. Aging in Escherichia coli: stochasticity, individual heterogeneity and mortality plateaus

    DEFF Research Database (Denmark)

    Steiner, Uli

    2014-01-01

    suggested to be involved in aging and senescence, but no mechanism or factor has been unambiguously identified. Here, we report on surprising patterns of aging and senescence from isogenic individual Escherichia coli bacteria grown under identical environmental conditions in a microfluidic device. Such...

  18. 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 ...

  19. 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...

  20. 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 Mg x ATP and ribose 5-phosphate as well as Mg2+ to the enzyme 5-phospho-D-ribosyl (alpha-1-diphosphate synthetase from Escherichia coli has been analyzed. By use of the competive inhibitors of ATP and ribose 5-phosphate binding, alpha,beta-methylene ATP ...

  1. 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

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

    Directory of Open Access Journals (Sweden)

    Fernanda Morcatti Coura

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  4. Inhibitor-resistant TEM- and OXA-1-producing Escherichia coli isolates resistant to amoxicillin-clavulanate are more clonal and possess lower virulence gene content than susceptible clinical isolates.

    Science.gov (United States)

    Oteo, Jesús; González-López, Juan José; Ortega, Adriana; Quintero-Zárate, J Natalia; Bou, Germán; Cercenado, Emilia; Conejo, María Carmen; Martínez-Martínez, Luis; Navarro, Ferran; Oliver, Antonio; Bartolomé, Rosa M; Campos, José

    2014-07-01

    In a previous prospective multicenter study in Spain, we found that OXA-1 and inhibitor-resistant TEM (IRT) β-lactamases constitute the most common plasmid-borne mechanisms of genuine amoxicillin-clavulanate (AMC) resistance in Escherichia coli. In the present study, we investigated the population structure and virulence traits of clinical AMC-resistant E. coli strains expressing OXA-1 or IRT and compared these traits to those in a control group of clinical AMC-susceptible E. coli isolates. All OXA-1-producing (n = 67) and IRT-producing (n = 45) isolates were matched by geographical and temporal origin to the AMC-susceptible control set (n = 56). We performed multilocus sequence typing and phylogenetic group characterization for each isolate and then studied the isolates for the presence of 49 virulence factors (VFs) by PCR and sequencing. The most prevalent clone detected was distinct for each group: group C isolates of sequence type (ST) 88 (C/ST88) were the most common in OXA-1 producers, B2/ST131 isolates were the most common in IRT producers, and B2/ST73 isolates were the most common in AMC-susceptible isolates. The median numbers of isolates per ST were 3.72 in OXA-1 producers, 2.04 in IRT producers, and 1.69 in AMC-susceptible isolates; the proportions of STs represented by one unique isolate in each group were 19.4%, 31.1%, and 48.2%, respectively. The sum of all VFs detected, calculated as a virulence score, was significantly higher in AMC-susceptible isolates than OXA-1 and IRT producers (means, 12.5 versus 8.3 and 8.2, respectively). Our findings suggest that IRT- and OXA-1-producing E. coli isolates resistant to AMC have a different and less diverse population structure than AMC-susceptible clinical E. coli isolates. The AMC-susceptible population also contains more VFs than AMC-resistant isolates. PMID:24777096

  5. Escherichia coli Isolates Causing Asymptomatic Bacteriuria in Catheterized and Noncatheterized Individuals Possess Similar Virulence Properties

    DEFF Research Database (Denmark)

    Watts, Rebecca E; Hancock, Viktoria; Ong, Cheryl-lynn Y;

    2010-01-01

    Urinary tract infections (UTIs) are among the most common infectious diseases of humans, with Escherichia coli being responsible for >80% of all cases. Asymptomatic bacteriuria (ABU) occurs when bacteria colonize the urinary tract without causing clinical symptoms and can affect both catheterized...... patients (catheter-associated ABU [CA-ABU]) and noncatheterized patients. Here, we compared the virulence properties of a collection of ABU and CA-ABU nosocomial E. coli isolates in terms of antibiotic resistance, phylogenetic grouping, specific UTI-associated virulence genes, hemagglutination...... previously described for the prototype ABU E. coli strain, 83972. This is the first global gene expression analysis of E. coli CA-ABU strains. Overall, our data suggest that nosocomial ABU and CA-ABU E. coli isolates possess similar virulence profiles....

  6. Platinum Nanoparticles Modified Electrode for Rapid Electrochemical Detection of Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    CHENG Yu-Xiao; LIU Ya-Jun; HUANG Jing-Jing; FENG Zhen; XIAN Yue-Zhong; WU Zi-Rong; ZHANG Wen; JIN Li-Tong

    2008-01-01

    A platinum nanoparticles chemically modified electrode (PtNP/GCE) was fabricated by electro-deposition and used to detection of Escherichia coli (E.coli).The detection principle was based on determination of p-aminophenol that was produced by an enzymatic reaction in E.coli solution.The sensitivity of the detection was improved by the platinum nanoparticle modified electrode and optimization of the detection system.The current responses were proportional to the density of E.coli ranging from 50 to 1.0× 105 cfu/mL, with detection limit of 20 cfu/mL, and the detection time was less than 4 h.Compared with conventional methods, the electrochemical technology described here could be suitable for rapid detection of E.coli in the fields of food industry, environmental monitoring and clinic biomedicine.

  7. Pathogenicity of Escherichia coli O123 from Rex Rabbit on White Mice

    Institute of Scientific and Technical Information of China (English)

    Wang; Yanping; Guo; Shijin; Yang; Limei; Dong; Lin; Xu; Qianqian; Shen; Zhiqiang

    2014-01-01

    [Objective]The paper was to analyze the pathogenesis of Escherichia coli O123 from rex rabbit. [Method]E. coli O123 isolated from rabbit liver with diarrhea symptom in scale rex rabbit farm was intraperitoneally injected into 18- 22 g Kunming mice,and its pathogenicity was determined by clinical symptoms and pathological examination. [Result]When the inoculation concentration was about 8. 5 × 107 CFU /mL,Kunming mice appeared the clinical symptoms of drooping spirit,diarrhea and gathering,and the mortality reached 50%. Anatomical examination found that intestinal wall was thinning and intestinal mucosa was bleeding. [Conclusion]E. coli from rex rabbit has strong pathogenicity,and establishing animal model with Kunming mice to study its pathogenesis is of great reference significance for diagnosis and prevention of E. coli disease of rex rabbit.

  8. In vitro killing of Escherichia coli, Staphylococcus pseudintermedius and Pseudomonas aeruginosa by enrofloxacin in combination with its active metabolite ciprofloxacin using clinically relevant drug concentrations in the dog and cat.

    Science.gov (United States)

    Blondeau, J M; Borsos, S; Blondeau, L D; Blondeau, B J

    2012-03-23

    Enrofloxacin is a fluoroquinolone antibacterial agent used to treat infections in companion animals. Enrofloxacin's antimicrobial spectrum includes Gram positive and Gram-negative bacteria and demonstrates concentration-dependent bacteriocidal activity. In dogs and cats, enrofloxacin is partially metabolized to ciprofloxacin and both active agents circulate simultaneously in treated animals at ratios of approximately 60-70% enrofloxacin to 30-40% ciprofloxacin. We were interested in determining the killing of companion animal isolates of Escherichia coli, Staphylococcus pseudintermedius and Pseudomonas aeruginosa by enrofloxacin and ciprofloxacin combined using clinically relevant drug concentrations and ratios. For E. coli isolates exposed to 2.1 and 4.1μg/ml of enrofloxacin/ciprofloxacin at 50:50, 60:40 and 70:30 ratios, a 1.7-2.5log(10) reduction (94-99% kill) was seen following 20min of drug exposure; 0.89-1.7log(10) (92-99% kill) of S. pseudintermedius following 180min of drug exposure; 0.85-3.4log(10) (98-99% kill) of P. aeruginosa following 15min of drug exposure. Killing of S. pseudintermedius was enhanced in the presence of enrofloxacin whereas killing of P. aeruginosa was enhanced in the presence of ciprofloxacin. Antagonism was not seen when enrofloxacin and ciprofloxacin were used in kill assays. The unique feature of partial metabolism of enrofloxacin to ciprofloxacin expands the spectrum of enhanced killing of common companion animal pathogens. PMID:21925810

  9. Translational Inhibition of CTX-M Extended Spectrum β-Lactamase in Clinical Strains of Escherichia coli by Synthetic Antisense Oligonucleotides Partially Restores Sensitivity to Cefotaxime.

    Science.gov (United States)

    Readman, John B; Dickson, George; Coldham, Nick G

    2016-01-01

    Synthetic antisense oligomers are DNA mimics that can specifically inhibit gene expression at the translational level by ribosomal steric hindrance. They bind to their mRNA targets by Watson-Crick base pairing and are resistant to degradation by both nucleases and proteases. A 25-mer phosphorodiamidate morpholino oligomer (PMO) and a 13-mer polyamide (peptide) nucleic acid (PNA) were designed to target mRNA (positions -4 to +21, and -17 to -5, respectively) close to the translational initiation site of the extended-spectrum β-lactamase resistance genes of CTX-M group 1. These antisense oligonucleotides were found to inhibit β-lactamase activity by up to 96% in a cell-free translation-transcription coupled system using an expression vector carrying a bla CTX-M-15 gene cloned from a clinical isolate. Despite evidence for up-regulation of CTX-M gene expression, they were both found to significantly restore sensitivity to cefotaxime (CTX) in E. coli AS19, an atypical cell wall permeable mutant, in a dose dependant manner (0-40 nM). The PMO and PNA were covalently bound to the cell penetrating peptide (CPP; (KFF)3K) and both significantly (P < 0.05) increased sensitivity to CTX in a dose dependent manner (0-40 nM) in field and clinical isolates harboring CTX-M group 1 β-lactamases. Antisense oligonucleotides targeted to the translational initiation site and Shine-Dalgarno region of bla CTX-M-15 inhibited gene expression, and when conjugated to a cell penetrating delivery vehicle, partially restored antibiotic sensitivity to both field and clinical isolates. PMID:27047482

  10. Uji Antibakteri Ekstak Daun Sirsak (Annonamuricata Linn) terhadap Bakteri Escherichia coli dan Staphylococcusaureus

    OpenAIRE

    Pradikta, Rina

    2015-01-01

    Antibacterial activity of methanol extract soursop leaf (Annona muricata Linn) toEscherichia coli, and Staphylococcus aureus with diffusionmethod has been done. Result showed soursop leaf methanol extract (Annona muricata Linn) has activity as antibacterial. at concentration of 10 % to Escherichia coli and Staphylococcus aureus with resistancediameter of 10 mm to Escherichia coli, and 8,52 mm to Staphylococcus aureus each. While in the water solvent resistent diameter for bacteria Escherichia...

  11. Alterations induced in Escherichia Coli cells by gamma radiation

    International Nuclear Information System (INIS)

    Modifications occurred in Escherichia coli cells exposed to gamma radiation (60Co 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)

  12. SILAC-based comparative analysis of pathogenic Escherichia coli secretomes

    DEFF Research Database (Denmark)

    Boysen, Anders; Borch, Jonas; Krogh, Thøger Jensen;

    2015-01-01

    this study, we grew the pathogenic strains ETEC H10407, AIEC LF82 and the non-pathogenic reference strain E. coli K-12 MG1655 in parallel and used SILAC to compare protein levels in OMVs and culture supernatant. We have identified well-known virulence factors from both AIEC and ETEC, thus validating......Comparative studies of pathogenic bacteria and their non-pathogenic counterparts has led to the discovery of important virulence factors thereby generating insight into mechanisms of pathogenesis. Protein-based antigens for vaccine development are primarily selected among unique virulence...... proteome analysis have the potential to discover both classes of proteins and hence form an important tool for discovering therapeutic targets. Adherent-invasive Escherichia coli (AIEC) and Enterotoxigenic E. coli (ETEC) are pathogenic variants of E. coli which cause intestinal disease in humans. AIEC is...

  13. 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...

  14. Anti - microbial resistance stratified by risk factor among Escherichia coli strains isolated from the urinary tract at a rural clinic in Central India

    Directory of Open Access Journals (Sweden)

    Chatterjee B

    2009-01-01

    Full Text Available Background: The failure of empirical therapy is frequently observed, even in community-acquired urinary tract infections. We, therefore, conducted a prospective, clinic-based study in 2004-2005 to document anti-microbial resistance rates and correlate them with possible risk factors to assist empirical decision-making. Materials and Methods: Symptomatic patients with pyuria underwent urine culture. Isolates were identified using standard methods and anti-microbial resistance was determined by disk-diffusion. Ultrasonography was used to detect complicating factors. Patients were stratified by the presence of complicating factors and history of invasive procedures for comparison of resistance rates. Statistical Method Used: Chi-square or Fisher exact tests, as appropriate. Results: There were 156 E. coli isolates, of which 105 were community-acquired. Twenty-three community-acquired isolates were from patients with complicating factors while 82 were from patients without any. Fifty-one isolates were from patients who had recently undergone invasive procedures on the urinary tract. Thirty-two community-acquired isolates from reproductive-age women without apparent complicating factors had resistance rates of 50% or above against tetracyclines, Co-trimoxazole, aminopenicillins, Nalidixic acid, Ciprofloxacin and 1 st generation cephalosporins. Resistance rates were significantly higher among isolates from patients subjected to invasive procedures, except against Co-trimoxazole, tetracyclines and Amikacin. Conclusion: High rates of anti-microbial resistance in community-acquired uropathogens have made antimicrobial sensitivity testing necessary even in a rural, primary-care setting.

  15. Possibility of CTX-M-14 Gene Transfer from Shigella sonnei to a Commensal Escherichia coli Strain of the Gastroenteritis Microbiome

    OpenAIRE

    Cho, Seung-Hak; Han, Soon Young; Kang, Yeon-Ho

    2014-01-01

    Objectives To investigated whether the CTX-M-14 gene could be transferred from a clinical Shigella sonnei strain to commensal Escherichia coli strain in the gastroenteritis microbiome. Methods E. coli strains were isolated from 30 stool samples of S. sonnei infected students in a gastroenteritis outbreak in 2004 and were characterized by antibiotic resistance analysis, in vitro conjugation and in vivo transfer of CTX-M-14 gene and molecular assays. Results One strain of Escherichia coli that ...

  16. Translational inhibition of CTX M extended spectrum β-lactamase in clinical strains of Escherichia coli by synthetic antisense oligonucleotides partially restores sensitivity to cefotaxime.

    Directory of Open Access Journals (Sweden)

    John Benedict Readman

    2016-03-01

    Full Text Available Synthetic antisense oligomers are DNA mimics that can specifically inhibit gene expression at the translational level by ribosomal steric hindrance. They bind to their mRNA targets by Watson Crick base pairing and are resistant to degradation by both nucleases and proteases. A 25 mer phosphorodiamidate morpholino oligomer (PMO and a 13 mer polyamide (peptide nucleic acid (PNA were designed to target mRNA (positions -4 to +21, and –17 to –5 respectively close to the translational initiation site of the extended spectrum β lactamase resistance genes of CTX M group 1. These antisense oligonucleotides were found to inhibit β lactamase activity by up to 96% in a cell free translation transcription coupled system using an expression vector carrying a blaCTX-M-15 gene cloned from a clinical isolate. Despite evidence for up regulation of CTX-M gene expression, they were both found to significantly restore sensitivity to cefotaxime in E. coli AS19, an atypical cell wall permeable mutant, in a dose dependant manner (0 - 40 nM. The PMO and PNA were covalently bound to the cell penetrating peptide (KFF3K and both significantly (P<0.05 increased sensitivity to cefotaxime in a dose dependent manner (0 - 40 nM in field isolates harbouring CTX-M group 1 β-lactamases. Antisense oligonucleotides targeted to the translational initiation site and Shine Dalgarno region of blaCTX-M-15 inhibited gene expression, and when conjugated to a cell penetrating delivery vehicle, partially restored antibiotic sensitivity to both field and clinical isolates.

  17. Escherichia coli as Host and Pathogen

    OpenAIRE

    2013-01-01

    Enterohemorrhagic E. coli (EHEC) are highly infectious food-borne pathogens that cause severe diarrhoea in both, industrialised and developing countries all over the world. Their pathogenicity factors involve shiga-like toxins and a type III secretion system along with so called effector proteins, which are translocated directly into the cytoplasm of their host cells, usually enterocytes. Most of these proteins are encoded in pathogenicity islands within the bacterial genome that are framed b...

  18. Mutators and hypermutability in bacteria: the Escherichia coli paradigm

    Indian Academy of Sciences (India)

    R. Jayaraman

    2009-12-01

    Mutators (also called hypermutators) are mutants which show higher than normal spontaneous mutation frequencies, ranging from 10–20 fold to 100–1000 fold higher, or sometimes even more, than wild-type cells. Being a mutator is advantageous to the organism when adapting to environmental changes or stressful situations, such as moving from one habitat to another, one host to another, exposure to antibiotics etc. However, this advantage is only a short-term benefit. In the long run, hypermutability leads to a fitness disadvantage due to accumulation of deleterious mutations or antagonistic pleiotropy or both. Contrary to intuitive expectations, hypermutability is commonly encountered in natural bacterial populations, especially among clinical isolates. It is believed to be involved in the emergence of antibiotic resistance and a hindrance to the treatment of infectious diseases. Here, I review the state of knowledge on the common mechanisms of hypermutability such as errors/defects in DNA replication, proof reading, mismatch repair, oxidative DNA damage, mistranslation etc., as well as phenomena associated with these processes, using Escherichia coli as a paradigmatic organism.

  19. Binding characteristics of Escherichia coli adhesins in human urinary bladder.

    OpenAIRE

    Virkola, R; Westerlund, B; Holthöfer, H; Parkkinen, J; Kekomäki, M; Korhonen, T K

    1988-01-01

    We studied domains in the human bladder that acted as receptors for Escherichia coli P, S, type 1, type 1C, and O75X fimbriae or adhesin and domains in the human kidneys that were receptors for E. coli type 1C fimbriae. Binding sites in frozen tissue sections were localized by direct staining with fluorochrome-labeled recombinant strains and by indirect immunofluorescence with the purified adhesins. In the bladder, the P and S fimbriae showed closely similar binding to the epithelial and musc...

  20. DNA microarray analysis of fim mutations in Escherichia coli

    DEFF Research Database (Denmark)

    Schembri, Mark; Ussery, David; Workman, Christopher;

    2002-01-01

    Bacterial adhesion is often mediated by complex polymeric surface structures referred to as fimbriae. Type I fimbriae of Escherichia coli represent the archetypical and best characterised fimbrial system. These adhesive organelles mediate binding to D-mannose and are directly associated with...... we have used DNA microarray analysis to examine the molecular events involved in response to fimbrial gene expression in E. coli K-12. Observed differential expression levels of the fim genes were in good agreement with our current knowledge of the stoichiometry of type I fimbriae. Changes in fim...

  1. Novel Aggregative Adherence Fimbria Variant of Enteroaggregative Escherichia coli

    DEFF Research Database (Denmark)

    Jønsson, Rie; Struve, Carsten; Boisen, Nadia;

    2015-01-01

    Enteroaggregative Escherichia coli (EAEC) organisms belong to a diarrheagenic pathotype known to cause diarrhea and can be characterized by distinct aggregative adherence (AA) in a stacked-brick pattern to cultured epithelial cells. In this study, we investigated 118 EAEC strains isolated from the....... Transformation to a nonadherent E. coli HB101 and complementation of the nonadherent C338-14 mutant with the complete gene cluster restored the AA adhesion. Overall, we found the agg5A gene in 12% of the 118 strains isolated from Denmark, suggesting that this novel adhesin represents an important variant....

  2. Recombinant protein expression in Escherichia coli: advances and challenges

    Directory of Open Access Journals (Sweden)

    GermánLeandroRosano

    2014-04-01

    Full Text Available Escherichia coli is the organism of choice for the production of recombinant proteins. Its use as a cell factory is well-established and it has become the most popular expression platform. For this reason, there are many molecular tools and protocols at hand for the high-level production of recombinant proteins, such as a vast catalog of expression plasmids, a great number of engineered strains and many cultivation strategies. We review the different approaches for the synthesis of recombinant proteins in E. coli and discuss recent progress in this ever-growing field.

  3. Antibacterial behavior of diamond nanoparticles against Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Beranova, Jana; Seydlova, Gabriela [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 16200 Prague (Czech Republic); Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Vinicna 5, 12844 Prague (Czech Republic); Kozak, Halyna; Potocky, Stepan; Kromka, Alexander [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 16200 Prague (Czech Republic); Konopasek, Ivo [Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Vinicna 5, 12844 Prague (Czech Republic)

    2012-12-15

    In this study, we investigated the potential antibacterial properties of nanocrystalline diamond. In particular, we tested the effect of diamond nanoparticles (DNPs) on growth of the model gram-negative bacterium Escherichia coli on solid, nutrient-rich growth medium. We found that the presence of DNPs on agar plates significantly reduced the colony forming ability of E. coli. The antibacterial effect occurred in a concentration dependent manner and was conditional on the specific ratio of DNPs to the number of bacterial cells. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Genetic determinants of heat resistance in Escherichia coli

    OpenAIRE

    Ryan eMercer; Jinshui eZheng; Rigoberto eGarcia-Hernandez; Lifang eRuan; Michael eGänzle; Lynn eMcMullen

    2015-01-01

    Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 mi...

  5. 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...

  6. Properties and biosynthesis of cyclopropane fatty acids in Escherichia coli.

    Science.gov (United States)

    Cronan, J E; Reed, R; Taylor, F R; Jackson, M B

    1979-01-01

    The lipid phase transition of Escherichia coli phospholipids containing cyclopropane fatty acids was compared with the otherwise homologous phospholipids lacking cyclopropane fatty acids. The phase transitions (determined by scanning calorimetry) of the two preparations were essentially identical. Infection of E. coli with phage T3 inhibited cyclopropane fatty acid formation over 98%, whereas infection with mutants which lack the phage coded S-adenosylmethionine cleavage enzyme had no effect on cyclopropane fatty acid synthesis. These data indicate that S-adenosylmethionine is the methylene in cyclopropane fatty acid synthesis. PMID:374358

  7. Molecular basis of valine resistance in Escherichia coli K-12.

    OpenAIRE

    Lawther, R P; Calhoun, D H; Adams, C W; Hauser, C A; Gray, J.; Hatfield, G W

    1981-01-01

    The relationship of valine resistance to the expression of the ilvGEDA operon of Escherichia coli K-12 has been determined. DNA sequence and in vivo protein analyses indicate that in wild-type E. coli K-12 there is a frameshift site within the gene (ilvG) for valine resistance. The ilvG+2096 (formerly designated ilv02096) mutation displaces this frameshift site, resulting in the expression of ilvG and the relief of transcriptional polarity on the distal genes of this operon. Thus, the "ilv0" ...

  8. Occurrence of False Positive Results for the Detection of Carbapenemases in Carbapenemase-Negative Escherichia coli and Klebsiella pneumoniae Isolates

    OpenAIRE

    Wang, Peng; Chen, Shudan; Guo, Yan; Xiong, Zizhong; Hu, Fupin; Zhu, Demei; Zhang, Yingyuan

    2011-01-01

    Adequate detection of the production of carbapenemase in Enterobacteriaceae isolates is crucial for infection control measures and the appropriate choice of antimicrobial therapy. In this study, we investigated the frequency of false positive results for the detection of carbapenemases in carbapenemase-negative Escherichia coli and Klebsiella pneumoniae clinical isolates by the modified Hodge test (MHT). Three hundred and one E. coli and K. pneumoniae clinical isolates were investigated. All ...

  9. Dexamethazone protects against Escherichia coli induced sickness behavior in rats.

    Science.gov (United States)

    Hanaa-Mansour, A; Hassan, Wedad A; Georgy, Gehan S

    2016-01-01

    Systemic bacterial infection results in systemic inflammatory response syndrome due to the release of lipopolysaccharide (LPS) in blood that can lead to multiple organ failure, shock, and potentially death. Other impact, LPS exposure produces robust increase in anxiety-like behavior, suppression of locomotor, exploratory activity, and reduced social behavior. The therapeutic use of glucocorticoids in septic shock remains one of the first-aid approaches for their anti-inflammatory properties. The aim of this study was to evaluate the possible protective effect of dexamethazone (DEX), the most commonly used corticosteroid, against Escherichia coli (E. coli) immunohistochemical changes and neurobehavioral dysfunction. To this end, male Sprague-Dawley rats were divided into four groups; (1) Control group (2) E. coli infected group, where animals received 0.2 ml of 24 h growth of E. coli suspension in nutrient broth containing approximately 1.8×10(8) cfu/ml i.p for once, 48 h before sacrificing (3) DEX (20 mg/kg, i.p, 3 days) treated group (4) DEX and E. coli treated group. The results revealed that DEX significantly protected animals against most E. coli-induced behavioral deficits, reduced signs of cognitive impairment. DEX also reduced the LPS-evoked rise in C-reactive protein (CRP), Interferon gamma (IFγ), as well as, expression of Caspase-3. In conclusion, DEX provides neuroprotection against E. coli-associated neurobehavioral and immunological changes via its anti-inflammatory and immunomodulatory effects. PMID:26541583

  10. 喹诺酮耐药大肠埃希菌尿道感染现状及危险因素分析%Quinolone resistant Escherichia coli isolated from urinary tract infection:clinical status and risk factors

    Institute of Scientific and Technical Information of China (English)

    张安兵

    2012-01-01

    Objective To investigate the quinolone resistant Escherkhia coli infection status and risk factors, and provide a basis for selecting appropriate antibiotics in the clinical practice. Methods This study is a retrospective review from 2010 to 2011. 348 strains Escherichia coli isolated from urine specimens were analysis, using the quinolone susceptible isolates as the control group. The risk factors for the quinolone resistance strains were analyzed. Results Of the 348 E.coli strains isolated from urinary tract infection patient, 58.3% (203)were quinolone resistant. Logistic regression analysis showed three generation cephalosporins and quinolones drug use, urinary drainage and bacterium producing extra-broad spectrum beta-lactamase were the independent risk factors for ciprofloxacin resistance of E.coli strains isolated from urinary tract infection patients. Conclusion The epidemic of quinolone resistant Escherichia coli isolated from urine specimens were extremely serious. The drug resistance of the quinolone resistant isolates was strong. The patients infected with quinolone resistant strains had high medical cost and longer average length of stay in hospital. The quinolone resistant E.coli infection with multiple independent risk factors, the strengthening of these independent risk factor controls can effectively prevent the spread of quinolone resistant strains infection.%目的 分析喹诺酮耐药大肠埃希菌尿道感染现状及危险因素,为临床合理选用抗生素提供依据.方法 回顾性分析348例大肠埃希菌尿道感染临床现状,以喹诺酮敏感大肠埃希菌为对照菌株,对喹诺酮耐药大肠埃希菌感染危险因素进行分析.结果 348株大肠埃希菌尿道感染中检出喹诺酮耐药菌203株,占58.3%.Logistic回归分析显示三代头孢菌素及喹诺酮类药物使用、尿路引流和细菌产超广谱β-内酰胺酶是喹诺酮耐药大肠埃希菌感染的独立危险因素.结论 尿道感染大肠埃

  11. Mechanobiology of Antimicrobial Resistant Escherichia coli and Listeria innocua

    Science.gov (United States)

    Tajkarimi, Mehrdad; Harrison, Scott H.; Hung, Albert M.; Graves, Joseph L.

    2016-01-01

    A majority of antibiotic-resistant bacterial infections in the United States are associated with biofilms. Nanoscale biophysical measures are increasingly revealing that adhesive and viscoelastic properties of bacteria play essential roles across multiple stages of biofilm development. Atomic Force Microscopy (AFM) applied to strains with variation in antimicrobial resistance enables new opportunities for investigating the function of adhesive forces (stickiness) in biofilm formation. AFM force spectroscopy analysis of a field strain of Listeria innocua and the strain Escherichia coli K-12 MG1655 revealed differing adhesive forces between antimicrobial resistant and nonresistant strains. Significant increases in stickiness were found at the nanonewton level for strains of Listeria innocua and Escherichia coli in association with benzalkonium chloride and silver nanoparticle resistance respectively. This advancement in the usage of AFM provides for a fast and reliable avenue for analyzing antimicrobial resistant cells and the molecular dynamics of biofilm formation as a protective mechanism. PMID:26914334

  12. Klinischer Einsatz und Immunmodulation durch apathogene Escherichia coli Nissle 1917 bei Gräserpollenallergikern

    OpenAIRE

    Berg, Jennifer

    2013-01-01

    Non-pathogenic Escherichia coli Nissle 1917 (EcN) is a probiotic bacterium, which has immunomodulatory properties. Herein, we investigated the efficacy and tolerability of EcN in subjects with grass pollen dependent allergic rhinoconjunctivitis. Grass pollen allergic subjects were blinded randomised and orally supplemented with either EcN or placebo beginning two months before the onset of and during one grass pollen season (6 months). Clinical symptoms and the intake of anti-allergic medicat...

  13. Virulence factors, serogroups and antimicrobial resistance properties of Escherichia coli strains in fermented dairy products

    OpenAIRE

    Dehkordi, Farhad Safarpoor; Yazdani, Farshad; Mozafari, Jalal; Valizadeh, Yousef

    2014-01-01

    Background From a clinical perspective, it is essential to know the microbial safety of fermented dairy products. Doogh and kashk are fermented dairies. These products are used by millions of people but their microbial qualities are unknown. Shiga toxin producing Escherichia coli (STEC) is one of the most commonly detected pathogens in the cases of food poisoning and food-borne illnesses. The present investigation was carried out in order to study the molecular characterization and antimicrob...

  14. Genetic Background of Escherichia coli and Extended-spectrum β-Lactamase Type

    OpenAIRE

    Branger, Catherine; Zamfir, Oana; Geoffroy, Sabine; Laurans, Geneviève; Arlet, Guillaume; Thien, Hoang Vu; Gouriou, Stéphanie; Picard, Bertrand; Denamur, Erick

    2005-01-01

    To assess the implication of the genetic background of Escherichia coli strains in the emergence of extended-spectrum-β-lactamases (ESBL), 55 TEM-, 52 CTX-M-, and 22 SHV-type ESBL-producing clinical isolates involved in various extraintestinal infections or colonization were studied in terms of phylogenetic group, virulence factor (VF) content (pap, sfa/foc, hly, and aer genes), and fluoroquinolone resistance. A factorial analysis of correspondence showed that SHV type, and to a lesser extent...

  15. Physical characterization of plasmids determining synthesis of a microcin which inhibits methionine synthesis in Escherichia coli.

    OpenAIRE

    Perez-Diaz, J C; Clowes, R C

    1980-01-01

    Plasmid deoxyribonucleic acid (DNA) isolated from each of three antibiotic-resistant clinical strains of Escherichia coli producing the same microcin showed multiple bands upon agarose gel electrophoresis. Transformants selected either for microcin resistance or ampicillin resistance yielded plasmid DNA corresponding in size to only one of the multiple bands. Plasmids, isolated from all three hosts, which determined microcin resistance and microcin production measured about 4 megadaltons by s...

  16. Shiga-Toxin bildende Escherichia coli in Milchviehbetrieben Schleswig-Holsteins

    OpenAIRE

    Menrath, Andrea

    2010-01-01

    Shiga-Toxin producing Escherichia coli (STEC) are an emerging human health issue with special regard to their low infectious dose combined with serious sequelae of disease especially in children. Cattle are often infected, but without clinical signs of disease; hence, cattle derived foods could be contaminated. Different factors like the kind of husbandry, the diet and the herd management of cattle were identified as risk for shedding of STEC. However, the individual characteristics of the si...

  17. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells

    OpenAIRE

    K.S. Canuto; L.P.S. Sergio; O.R. Guimarães; Geller, M.; De Paoli, F; Fonseca, A.S.

    2015-01-01

    Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia coli cells that were exposed to ultraviolet C (UVC) radiati...

  18. Bromelain protects piglets from diarrhoea caused by oral challenge with K88 positive enterotoxigenic Escherichia coli

    OpenAIRE

    Chandler, D.; Mynott, T

    1998-01-01

    Background—K88 positive enterotoxigenic Escherichia coli (K88+ ETEC) is an important cause of diarrhoea in young piglets. K88+ ETEC pathogenesis relies on attachment to specific glycoprotein receptors located on the intestinal mucosa. Proteolytic treatment of these receptors in vitro and in vivo prevents attachment of K88+ ETEC to piglet small intestines and may be of clinical use to prevent K88+ ETEC pathogenesis. 
Aims—To determine whether bromelain, a proteolytic ex...

  19. First Report of Klebsiella pneumoniae-Carbapenemase-3-Producing Escherichia coli ST479 in Poland

    OpenAIRE

    Dominika Ojdana; Paweł Sacha; Dorota Olszańska; Piotr Majewski; Piotr Wieczorek; Jadwiga Jaworowska; Anna Sieńko; Anna Jurczak; Elżbieta Tryniszewska

    2015-01-01

    An increase in the antibiotic resistance among members of the Enterobacteriaceae family has been observed worldwide. Multidrug-resistant Gram-negative rods are increasingly reported. The treatment of infections caused by Escherichia coli and other Enterobacteriaceae has become an important clinical problem associated with reduced therapeutic possibilities. Antimicrobial carbapenems are considered the last line of defense against multidrug-resistant Gram-negative bacteria. Unfortunately, an in...

  20. Effect of subinhibitory concentrations of mecillinam on the serum susceptibility of Escherichia coli strains.

    OpenAIRE

    Taylor, P W; Gaunt, H; Unger, F M

    1981-01-01

    For serum-resistant clinical isolates of Escherichia coli were grown in the presence of various subinhibitory concentrations of mecillinam or pivmecillinam and then exposed to the bactericidal action of human serum. All strains became more serum susceptible as a result of pregrowth in medium containing mecillinam, but the concentration of antibiotic needed to produce the effect varied according to the strain being used. Production of ovoid or round cells was a prerequisite for sensitization t...

  1. Wide Distribution of O157-Antigen Biosynthesis Gene Clusters in Escherichia coli

    OpenAIRE

    Atsushi Iguchi; Hiroki Shirai; Kazuko Seto; Tadasuke Ooka; Yoshitoshi Ogura; Tetsuya Hayashi; Kayo Osawa; Ro Osawa

    2011-01-01

    Most Escherichia coli O157-serogroup strains are classified as enterohemorrhagic E. coli (EHEC), which is known as an important food-borne pathogen for humans. They usually produce Shiga toxin (Stx) 1 and/or Stx2, and express H7-flagella antigen (or nonmotile). However, O157 strains that do not produce Stxs and express H antigens different from H7 are sometimes isolated from clinical and other sources. Multilocus sequence analysis revealed that these 21 O157:non-H7 strains tested in this stud...

  2. Effect of Brominated Furanones on the Formation of Biofilm by Escherichia coli on Polyvinyl Chloride Materials

    OpenAIRE

    Lianhua, Ye; Yunchao, Huang; Geng, Xu; Youquang, Zhou; Guangqiang, Zhao; Yujie, Lei

    2013-01-01

    To study the influence of brominated furanones on the biofilm (BF) formation by Escherichia coli (E. coli) on polyvinyl chloride (PVC) material, and to provide new ways of surface modification of materials to clinically prevent biomaterial centered infection. Three brominated furanones, dissolved in ethanol, furanone-1(3,4-dibromo-5-hydroxyl-furanone), furanone-2(4-bromo-5-(4-methoxypheny)-3-(methylamino)-furanone), and furanone-3(3,4-dibromo-5,5-dimethoxypheny-2(5H)-furanone) with representa...

  3. A novel, double mutation in DNA gyrase A of Escherichia coli conferring resistance to quinolone antibiotics.

    OpenAIRE

    Truong, Q C; Nguyen Van, J C; Shlaes, D; Gutmann, L; Moreau, N J

    1997-01-01

    A spontaneous Escherichia coli mutant, named Q3, resistant to nalidixic acid was obtained from a previously described clinical isolate of E. coli, Q2, resistant to fluoroquinolones but susceptible to nalidixic acid (E. Cambau, F. Bordon, E. Collatz, and L. Gutmann, Antimicrob. Agents Chemother. 37:1247-1252, 1993). Q3 harbored the mutation Asp82Gly in addition to the Gly81Asp mutation of Q2. The different mutations leading to Gly81Asp, Asp82Gly, and Gly81AspAsp82Gly were introduced into the g...

  4. Findings of Escherichia coli and Enterococcus spp. in homemade cheese

    OpenAIRE

    Tambur Zoran; Opačić Dolores; Doder Radoje; Marković Miroslav

    2007-01-01

    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...

  5. Mechanistic aspects of thiamine biosynthesis in escherichia coli

    OpenAIRE

    Challand, M.R

    2011-01-01

    The biosynthesis of the vitamin thiamine is laden with interesting chemistry. In anaerobic bacteria (such as Escherichia coli) a reactive intermediate, dehydroglycine, required for the biosynthesis of the thiazole moiety is derived from cleavage of the C??C? bond of tyrosine in a reaction catalysed by the radical S-adenosyl-L-methionine (SAM) enzyme, tyrosine lyase (ThiH). The aromatic by-product of this reaction in vivo was unequivocally characterised as p-cresol, a result which supported pr...

  6. Polynucleotide Phosphorylase Protects Escherichia coli against Oxidative Stress†

    OpenAIRE

    Wu, Jinhua; Jiang, Zhe; Liu, Min; Gong, Xin; Wu, ShaoHui; Burns, Christopher M.; Li, Zhongwei

    2009-01-01

    Escherichia coli polynucleotide phosphorylase (PNPase) primarily functions in RNA degradation. It is an exoribonuclease and integral component of the multienzyme RNA degradosome complex [Carpousis et al. (1994) Cell 76, 889]. PNPase was previously shown to specifically bind a synthetic RNA containing the oxidative lesion 8-hydroxyguanine (8-oxoG) [Hayakawa et al. (2001) Biochemistry 40, 9977], suggesting a possible role in removing oxidatively damaged RNA. Here we show that PNPase binds to RN...

  7. Chromosome partition in Escherichia coli requires postreplication protein synthesis.

    OpenAIRE

    Donachie, W. D.; Begg, K J

    1989-01-01

    After inhibition of protein synthesis, the number of nuclear bodies (nucleoids) visible in cells of Escherichia coli B/rA corresponded closely to the number of completely replicated chromosomes. We calculated that nucleoid partition follows almost immediately after replication forks reach the chromosome terminus. We show that such a partition is dependent on protein synthesis and that this may reflect the requirement that cells must achieve a certain minimum length before partition (and subse...

  8. Occurrence of Escherichia coli in Wild Cottontail Rabbits.

    Science.gov (United States)

    Kozlowski, R; Glantz, P J; Anthony, R G

    1977-03-01

    Free-ranging cottontail rabbits (Sylvilagus floridanus) from two areas in central Pennsylvania were sampled over a 4-year period. Large numbers of coliforms were isolated from the intestinal tracts of these animals; in 136 of the 141 rabbits sampled, Escherichia coli was found to be a major component of the alimentary flora. Four serogroups (O7, O77, O73, and O103) were predominant among the isolates and were considered resistant coliflora of this species of cottontail rabbit. PMID:16345208

  9. Identification of Uropathogenic Escherichia coli Surface Proteins by Shotgun Proteomics

    OpenAIRE

    Walters, Matthew S.; Mobley, Harry L. T.

    2009-01-01

    Uropathogenic Escherichia coli (UPEC) cause the majority of uncomplicated urinary tract infections in humans. In the process of identifying candidate antigens for a vaccine, two methods for the identification of the UPEC surface proteome during growth in human urine were investigated. The first approach utilized a protease to ‘shave’ surface-exposed peptides from the bacterial cell surface and identify them by mass spectrometry. Although this approach has been successfully applied to a Gram-p...

  10. Expression of a proline-enriched protein in Escherichia coli.

    OpenAIRE

    Kangas, T T; Cooney, C L; Gomez, R F

    1982-01-01

    The feasibility of expressing repeated synthetic codons in bacterial cells was demonstrated by showing that repeated codons for proline were expressed in Escherichia coli. Recombinant DNA technology was used to clone synthetic polydeoxyguanylate:polydeoxycytidylate into the PstI site of plasmid pBR322. Recombinant plasmid pGC139 was shown by means of HaeIII restriction digestion to contain approximately 41 cloned base pairs; the cloned sequence was expressed as a fusion to an ampicillinase pr...

  11. Genetic Analysis of the Maltose A Region in Escherichia coli

    Science.gov (United States)

    Hatfield, Dolph; Hofnung, Maurice; Schwartz, Maxime

    1969-01-01

    The genetic map of the maltose A locus of Escherichia coli contains at least three closely linked genes, malT, malP, and malQ. The order of these genes is established by deletion mapping. MalP and malQ, the presumed structural genes for maltodextrin phosphorylase and amylomaltase, belong to the same operon. MalT may be a regulator gene involved in the positive control of this operon. PMID:4891257

  12. 2DBase: 2D-PAGE database of Escherichia coli

    OpenAIRE

    Vijayendran, Chandran; Burgemeister, Sebastian; Friehs, Karl; Niehaus, Karsten; Flaschel, Erwin

    2007-01-01

    We present a web-based integrated proteome database, termed 2DBase of Escherichia coli which was designed to store, compare, analyse, and retrieve various information obtained by 2D polyacrylamide gel electrophoresis and mass spectrometry. The main objectives of this database are (1) to provide the features for query and data-mining applications to access the stored proteomics data (2) to efficiently compare the specific protein spots present in the comparable proteome maps and (3) to analyse...

  13. Quinolone accumulation in Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.

    OpenAIRE

    McCaffrey, C; Bertasso, A; Pace, J.; Georgopapadakou, N H

    1992-01-01

    The accumulation of quinolones by Escherichia coli JF568, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus ATCC 29213 was measured by a modified fluorometric assay (J. S. Chapman and N. H. Georgopapadakou, Antimicrob. Agents Chemother. 33:27-29, 1989). The quinolones examined were fleroxacin, pefloxacin, norfloxacin, difloxacin, A56620, ciprofloxacin, ofloxacin, and Ro 09-1168. In all three organisms, uptake was complete in less than 5 min and was proportional to extracellular quinolone...

  14. Metabolic engineering of Escherichia coli for the production of cinnamaldehyde

    OpenAIRE

    Bang, Hyun Bae; Lee, Yoon Hyeok; Kim, Sun Chang; Sung, Chang Keun; Jeong, Ki Jun

    2016-01-01

    Background Plant parasitic nematodes are harmful to agricultural crops and plants, and may cause severe yield losses. Cinnamaldehyde, a volatile, yellow liquid commonly used as a flavoring or food additive, is increasingly becoming a popular natural nematicide because of its high nematicidal activity and, there is a high demand for the development of a biological platform to produce cinnamaldehyde. Results We engineered Escherichia coli as an eco-friendly biological platform for the productio...

  15. Structural systems biology evaluation of metabolic thermotolerance in Escherichia coli

    OpenAIRE

    Chang, Roger L.; Andrews, Kathleen; Kim, Donghyuk; Li, Zhanwen; Godzik, Adam; Palsson, Bernhard Ø.

    2013-01-01

    Genome scale network reconstruction has enabled predictive modeling of metabolism for many systems. Traditionally, protein structural information has not been represented in such reconstructions. Expanding a genome-scale model of Escherichia coli metabolism by including experimental and predicted protein structures enabled the analysis of protein thermostability in a network context, allowing prediction of protein activities that limit network function at super-optimal temperature and mechani...

  16. The stringent response and cell cycle arrest in Escherichia coli.

    OpenAIRE

    Daniel J Ferullo; Lovett, Susan T.

    2008-01-01

    The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes...

  17. The Stringent Response and Cell Cycle Arrest in Escherichia coli

    OpenAIRE

    Daniel J Ferullo; Lovett, Susan T.

    2008-01-01

    The bacterial stringent response, triggered by nutritional deprivation, causes an accumulation of the signaling nucleotides pppGpp and ppGpp. We characterize the replication arrest that occurs during the stringent response in Escherichia coli. Wild type cells undergo a RelA-dependent arrest after treatment with serine hydroxamate to contain an integer number of chromosomes and a replication origin-to-terminus ratio of 1. The growth rate prior to starvation determines the number of chromosomes...

  18. Conjugative plasmid transfer from Enterococcus faecalis to Escherichia coli.

    OpenAIRE

    Trieu-Cuot, P; Carlier, C; Courvalin, P

    1988-01-01

    The possibility of transfer of genetic information by conjugation from gram-positive to gram-negative bacteria was investigated with a pBR322-pAM beta 1 chimeric plasmid, designated pAT191. This shuttle vector, which possesses the tra functions of the streptococcal plasmid pAM beta 1, was conjugatively transferred from Enterococcus faecalis to Escherichia coli with an average frequency of 5 x 10(-9) per donor colony formed after mating.

  19. Widespread antibiotic resistance of diarrheagenic Escherichia coli and Shigella species

    OpenAIRE

    Azam Fatahi Sadeghabadi; Ali Ajami; Reza Fadaei; Masoud Zandieh; Elham Heidari; Mahmoud Sadeghi; Behrooz Ataei; Shervin Ghaffari Hoseini

    2014-01-01

    Background: Antibiotic resistance of enteric pathogens particularly Shigella species, is a critical world-wide problem and monitoring their resistant pattern is essential, because the choice of antibiotics is absolutely dependent on regional antibiotic susceptibility patterns. During summer 2013, an unusual increase in number of diarrheal diseases was noticed in Isfahan, a central province of Iran. Therefore, the antibiotic resistance of diarrheagenic Escherichia coli and Shigella species iso...

  20. Functional expression of mouse mdr1 in Escherichia coli.

    OpenAIRE

    Bibi, E; Gros, P.; Kaback, H R

    1993-01-01

    We describe functional expression of the mouse multidrug-resistance protein (P-glycoprotein; P-gp) in an Escherichia coli mutant defective in the outer membrane protease ompT. Heterologously expressed mdr1 appears as an unglycosylated species with an apparent molecular mass of 140 kDa in the membrane of the mutant. Unglycosylated mdr1 retains the ability to bind the photoactivatable drug analog [125I]iodoarylazidoprazosin and confers resistance to tetraphenylphosphonium (TPP+) and tetraphenyl...

  1. CRISPR-Cas Functional Module Exchange in Escherichia coli

    OpenAIRE

    Almendros, Cristóbal; Mojica, Francisco J. M.; Díez-Villaseñor, César; Guzmán, Noemí M.; García-Martínez, Jesús

    2014-01-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (cas) genes constitute the CRISPR-Cas systems found in the Bacteria and Archaea domains. At least in some strains they provide an efficient barrier against transmissible genetic elements such as plasmids and viruses. Two CRISPR-Cas systems have been identified in Escherichia coli, pertaining to subtypes I-E (cas-E genes) and I-F (cas-F genes), respectively. In order to unveil the evolutionary dynamics of ...

  2. Vaccinia DNA topoisomerase I promotes illegitimate recombination in Escherichia coli.

    OpenAIRE

    Shuman, S

    1989-01-01

    Vaccinia virus encapsidates a Mr 32,000 type IDNA topoisomerase. Although the vaccinia gene encoding the topoisomerase is essential for virus growth, the role of the enzyme in vivo remains unclear. In the present study, the physiologic consequences of vaccinia topoisomerase action have been examined in a heterologous system, Escherichia coli. The vaccinia topoisomerase gene was inducibly expressed in an int-lambda lysogen BL21(DE3) using a T7 RNA polymerase-based transcription system. Express...

  3. Clonal relationships among bloodstream isolates of Escherichia coli.

    OpenAIRE

    Maslow, J.N.; Whittam, T S; Gilks, C F; Wilson, R A; Mulligan, M E; Adams, K S; Arbeit, R D

    1995-01-01

    The clonal relationships among 187 bloodstream isolates of Escherichia coli from 179 patients at Boston, Mass., Long Beach, Calif., and Nairobi, Kenya, were determined by multilocus enzyme electrophoresis (MLEE), analysis of polymorphisms associated with the ribosomal operon (ribotyping), and serotyping. MLEE based on 20 enzymes resolved 101 electrophoretic types (ETs), forming five clusters; ribotyping resolved 56 distinct patterns concordant with the analysis by MLEE. The isolates at each s...

  4. Pathogenomics of the Virulence Plasmids of Escherichia coli

    OpenAIRE

    Johnson, Timothy J.; Lisa K. Nolan

    2009-01-01

    Summary: Bacterial plasmids are self-replicating, extrachromosomal elements that are key agents of change in microbial populations. They promote the dissemination of a variety of traits, including virulence, enhanced fitness, resistance to antimicrobial agents, and metabolism of rare substances. Escherichia coli, perhaps the most studied of microorganisms, has been found to possess a variety of plasmid types. Included among these are plasmids associated with virulence. Several types of E. col...

  5. Genome-Scale Thermodynamic Analysis of Escherichia coli Metabolism

    OpenAIRE

    Christopher S Henry; Jankowski, Matthew D.; Broadbelt, Linda J.; Hatzimanikatis, Vassily

    2005-01-01

    Genome-scale metabolic models are an invaluable tool for analyzing metabolic systems as they provide a more complete picture of the processes of metabolism. We have constructed a genome-scale metabolic model of Escherichia coli based on the iJR904 model developed by the Palsson Laboratory at the University of California at San Diego. Group contribution methods were utilized to estimate the standard Gibbs free energy change of every reaction in the constructed model. Reactions in the model wer...

  6. Uropathogenic Escherichia coli Flagella Aid in Efficient Urinary Tract Colonization

    OpenAIRE

    Wright, Kelly J.; Seed, Patrick C.; Hultgren, Scott J.

    2005-01-01

    In the murine model of urinary tract infections (UTI), cystitis by uropathogenic Escherichia coli (UPEC) occurs through an intimate relationship with the bladder superficial umbrella cell entailing cycles of adherence, invasion, intracellular bacterial community (IBC) formation, and dispersal (fluxing) from the intracellular environment. IBC dispersal is a key step that results in the spread of bacteria over the epithelial surface to initiate additional rounds of IBC formation. We investigate...

  7. 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 presence...... of virulence factors could be detected between healthy and diseased kits. By electron microscopy of faecal samples corona-, rota-, and calicivirus were demonstrated among healthy as well as diseased kits....

  8. Analysis of resynthesis tracts in repaired Escherichia coli deoxyribonucleic acid.

    OpenAIRE

    Kuemmerle, N; R. Ley; Masker, W

    1981-01-01

    Excision repair of ultraviolet radiation-induced damage in a wild-type strain of Escherichia coli has been examined, using two methods for characterizing the resynthesis step of the repair process. Comparison of data obtained after both isopycnic analysis of repaired deoxyribonucleic acid and sedimentation velocity analysis of deoxyribonucleic acid after selective photolysis of bromouracil-containing repaired regions has shown that the repaired deoxyribonucleic acid molecules contain a semico...

  9. relA Enhances the Adherence of Enteropathogenic Escherichia coli

    OpenAIRE

    Beny Spira; Gerson Moura Ferreira; Luiz Gustavo de Almeida

    2014-01-01

    Enteropathogenic Escherichia coli (EPEC) is a known causative agent of diarrhea in children. In the process of colonization of the small intestine, EPEC synthesizes two types of adhesins, the bundle-forming pilus (BFP) and intimin. The BFP pilus is an adhesin associated with the initial stages of adherence of EPEC to epithelial cells, while the outer membrane protein intimin carries out the intimate adherence that takes place at the third stage of infection. BFP is encoded by the bfp operon l...

  10. Induction and control of the autolytic system of Escherichia coli.

    OpenAIRE

    Leduc, M.; Kasra, R; van Heijenoort, J

    1982-01-01

    Various methods of inducing autolysis of Escherichia coli cells were investigated, some being described here for the first time. For the autolysis of growing cells only induction methods interfering with the biosynthesis of peptidoglycan were taken into consideration, whereas with harvested cells autolysis was induced by rapid osmotic or EDTA shock treatments. The highest rates of autolysis were observed after induction by moenomycin, EDTA, or cephaloridine. The different autolyses examined s...

  11. Mobilization of Thiobacillus ferrooxidans plasmids among Escherichia coli strains.

    OpenAIRE

    Rawlings, D. E.; Woods, D R

    1985-01-01

    Nonconjugative Thiobacillus ferrooxidans plasmids were mobilized at high frequencies among Escherichia coli strains by the IncP plasmid RP4 and at low frequencies by the IncN plasmid R46, but not by the IncW plasmid pSa. The mobilization region of a nonconjugative T. ferrooxidans plasmid was located on a 5.3-kilobase T. ferrooxidans DNA fragment.

  12. 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.

  13. 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...

  14. Detección y caracterización de Escherichia coli productor de toxina Shiga a partir de casos clínicos y de alimentos en Uruguay Detection and characterization of Shiga toxin - producing Escherichia coli from clinical cases and food in Uruguay

    Directory of Open Access Journals (Sweden)

    G. Varela

    2008-06-01

    Full Text Available Establecimos la frecuencia de aislamiento de Escherichia coli productor de toxina Shiga (STEC a partir de muestras clínicas y de alimentos, así como las características fenotípicas y genotípicas de las cepas recuperadas. Se analizaron 198 muestras fecales de niños con diarrea sanguinolenta (DS, 14 muestras fecales de niños con síndrome urémico hemolítico (SUH y 220 muestras de carne picada. También se estudiaron 4 cepas STEC aisladas de alimentos embutidos. Se recuperó STEC de 3 (1,5% de los niños con DS, de 1 (7% niño con SUH y de 4 (1,8% de las muestras de carne picada. Todas las cepas fueron eae y ehxA positivas. Los serotipos detectados fueron: O157:H7 (9 cepas, O26:H11 (2 cepas, O111:NM (1 cepa y O145:HNT (1 cepa. Todas las cepas O157:H7 portaron el subtipo eae-g1; las cepas O26:H11 y O145:HNT portaron el subtipo eae-b1 y la cepa O111:NM portó el subtipo eae-g2/q. Las cepas STEC del mismo serogrupo mostraron alta diversidad genética. En Uruguay STEC no sería agente frecuente de diarrea con sangre en niños. Sin embargo, las cepas recuperadas presentaron los genes asociados con enfermedad severa y 2 de los 3 niños infectados con STEC evolucionaron a SUH. La carne picada y otros alimentos serían vehículos importantes de O157:H7.We have assessed the frequency of Shiga toxin-producing Escherichia coli (STEC in clinical and food samples as well as studied the genotypic and phenotypic characteristics of the recovered strains. One hundred ninety eight fecal samples from children with bloody diarrhea (BD, 14 from children with hemolytic uremic syndrome (HUS, 220 ground beef samples and 4 STEC isolates from other beef-derived products were analyzed. The STEC strains were isolated from 3 (1.5% children with bloody diarrhea, 1 (7% from a child with HUS and 4 (1.8% from ground beef samples. All strains were eae and ehxA positive. The serotypes found were: O157:H7 (9 strains, O26:H11 (2, O111: NM (1 and O145:HNT (1. All O157:H7 STEC

  15. 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.

  16. Escherichia coli sequence type 131: epidemiology and challenges in treatment.

    Science.gov (United States)

    Qureshi, Zubair A; Doi, Yohei

    2014-05-01

    Escherichia coli ST131 has emerged as a global epidemic, multidrug-resistant clone of E. coli causing extra-intestinal infections. It is now highly prevalent among fluoroquinolone-resistant and CTX-M ESBL-producing E. coli isolates worldwide. Humans are likely the primary reservoir of ST131. Factors associated with its acquisition include residence in long-term care facilities and recent receipt of antimicrobial agents. E. coli ST131 causes a wide array of infections ranging from cystitis to life-threatening sepsis. Fluoroquinolones and trimethoprim-sulfamethoxazole are no longer adequate options for empiric therapy when E. coli ST131 is suspected from risk factors and local epidemiology. Expanded-spectrum cephalosporins, piperacillin-tazobactam and carbapenems are options to treat serious non-ESBL-producing E. coli ST131 infections, while carbapenems are indicated for ESBL-producing infections. There is a growing interest in reevaluating oral agents including fosfomycin and pivmecillinam for less serious infections such as uncomplicated cystitis. PMID:24694052

  17. 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 culture of E. coli harboring the plasmid comprising the containment system is left as stationary cells in suspension without nutrients, viability drops exponentially over a period of several days, in contrast to the control cells, which maintain viability nearly unaffected during the same period...

  18. 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.

  19. Impact of antibiotic restriction on resistance levels of Escherichia coli

    DEFF Research Database (Denmark)

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

    2016-01-01

    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 as a...... of E. coli. Results were directly compared with data from the control hospital utilizing a subtracted time series (STS). RESULTS: Direct comparison with the control hospital showed that the ASP was associated with a significant change in the level of use of cephalosporins [-151 DDDs/1000 bed-days (95......% 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...

  20. 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 is a...... potent bacterial adhesin associated with some diarrheagenic E. coli strains. AIDA mediates bacterial attachment to a broad variety of human and other mammalian cells. It is a surface-displayed autotransporter protein and belongs to the selected group of bacterial glycoproteins; only the glycosylated form...... 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 with...

  1. Investigation of Biofield Treatment on Antimicrobial Susceptibility, Biochemical Reaction Pattern and Biotyping of Enteropathogenic Multidrug-Resistant Escherichia coli Isolates

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Study background: Multidrug resistant Escherichia coli (MDR E. coli) has become a major health concern, and failure of treatment leads to huge health burden. Aim of the present study was to determine the impact of Mr. Trivedi’s biofield treatment on E. coli. Methods: Four MDR clinical lab isolates (LSs) of E. coli (LS 8, LS 9, LS 10, and LS 11) were taken and divided into two groups i.e. control and biofield treated. Control and treated samples were identified with respect...

  2. PREVALENCE AND ANTIBIOGRAM OF EXTENDED SPECTRUM BET A- LACTAMASE PRODUCING ESCHERICHIA COLI

    Directory of Open Access Journals (Sweden)

    Mohd.

    2013-04-01

    Full Text Available ABSTRACT: BACKGROUND: Beta lactams are the most extensively used group of antimicrobials, however growing resistance to these invaluable drugs mediated by extended spectrum beta-lactamase (ESBL enzymes is a major co ncern. The frequency of ESBL producing strains among clinical isolates has been steadily i ncreasing over the past few years that has generated a major problem in clinical therapeutics. OBJECTIVES: Our aim was to determine the prevalence of ESBL producing Escherichia coli, study their antibiogram and to evaluate the association between ESBL production and antibiotic r esistance in Escherichia coli. SETTINGS AND DESIGN: This prospective study was conducted in the Department of Microbiology, Jawaharlal Nehru Medical College, Aligarh Muslim Un iversity, Aligarh. STATISTICAL ANALYSIS USED: Chi-square test was used to analyze the data stati stically. Probability values less than 0.05 were considered significant. MATERIALS AND METHODS: Two hundred and eighty six consecutive, non-repeated isolates of Escherichia c oli obtained from pus, urine, blood, stool, throat swab, cervical swab, sputum, CSF and conjunct ival swab samples received in our bacteriology laboratory were analyzed in this study . These bacterial isolates were identified and tested for antibiotic sensitivity by standard micro biological procedures. Subsequently, they were screened and then phenotypically confirmed for E SBL production by phenotypic confirmatory disk diffusion test (PCDDT. RESULTS : Out of 286 isolates of Escherichia coli screened for ESBL production, 65.03% (n=186 were de tected to be positive using either ceftazidime or cefotaxime. In the screen positives, 91.94% (n=171 were phenotypically confirmed ESBL producers by PCDDT method. The overal l prevalence of ESBL producing Escherichia coli was 59.79% (n=171/286 with 87.72% obtained from in-patients and 12.28% from out-patients. Majority of ESBL producing Escheri chia coli were recovered from stool (73

  3. Escherichia coli portador de betalactamasas de espectro extendido: resistencia

    Directory of Open Access Journals (Sweden)

    Mª C. Miranda García

    2013-12-01

    Full Text Available Introducción: Escherichia coli es el microorganismo que con más frecuencia se encuentra implicado en infecciones nosocomiales y comunitarias, patógeno responsable en la etiología de infecciones de vías respiratorias altas, infecciones del tracto urinario, heridas quirúrgicas, sangre o gastroenteritis. En los últimos años ha experimentado importantes cambios encontrándose un aumento de infecciones por cepas de éstos microorganismos productores de betalactamasas de espectro extendido. Objetivos: Se decide hacer este estudio retrospectivo de las muestras procesadas en el Laboratorio de Microbiología del Hospital Básico de la Defensa San Carlos (San Fernando, para conocer la frecuencia y el patrón de sensibilidad en nuestra población por gérmenes productores de betalactamasas de espectro extendido en este caso por Escherichia coli, dada la importancia de las infecciones causadas por esta bacteria y la repercusión que tiene por todo el mundo los mecanismos de resistencia. Material y Método: Se recogieron los datos de resultados obtenidos en las muestras procesadas en el Laboratorio de Microbiología durante 36 meses (Enero 2009 a Diciembre 2011, en las que se hubieran identificado cepas de Escherichia coli y de éstas las productoras de betalactamasas de espectro extendido. Resultados: Se aislaron 34 cepas de Escherichia coli productoras de betalactamasas de espectro extendido lo que supone una tasa del 5,10%. Se encontró una frecuencia mayor en el año 2010 (6,9% que en el 2009 (2,61%, pero similar al 2011 (5,98%. Conclusión: La frecuencia de cepas Escherichia coli con betalactamasas de espectro extendido encontrada es similar a la de otros estudios realizados en España, pero la tasa de resistencia de algunos antimicrobianos como Amoxicilina/clavulánico, Cotrimoxazol y Fluorquinolonas en nuestra población es elevada.

  4. Effect of tannins on the in viro growth of Escherichia coli O157:H7 and in vivo growth of generic Escherichia coli excreted from steers

    Science.gov (United States)

    The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement o...

  5. Effective medicinal plants against enterohaemorrhagic Escherichia coli O157:H7.

    Science.gov (United States)

    Voravuthikunchai, Supayang; Lortheeranuwat, Amornrat; Jeeju, Wanpen; Sririrak, Trechada; Phongpaichit, Souwalak; Supawita, Thanomjit

    2004-09-01

    The stimulating effect of subinhibitory concentrations of antibiotics on the production of verocytotoxin (VT) by enterohaemorrhagic Escherichia coli (EHEC) O157:H7 has been claimed. The purpose of this study was to find an alternative, but bioactive medicine for the treatment of this organism. Fifty-eight preparations of aqueous and ethanolic extracts of 38 medicinal plant species commonly used in Thailand to cure gastrointestinal infections were tested for their antibacterial activity against different strains of Escherichia coli, including 6 strains of Escherichia coli O157:H7, Escherichia coli O26:H11, Escherichia coli O111:NM, Escherichia coli O22; 5 strains of Escherichia coli isolated from bovine; and Escherichia coli ATCC 25922. Inhibition of growth was primarily tested by the paper disc agar diffusion method. Among the medicinal plants tested, only 8 species (21.05%) exhibited antimicrobial activity against Escherichia coli O157:H7. Acacia catechu, Holarrhena antidysenterica, Peltophorum pterocarpum, Psidium guajava, Punica granatum, Quercus infectoria, Uncaria gambir, and Walsura robusta demonstrated antibacterial activity with inhibition zones ranging from 7 to 17 mm. The greatest inhibition zone against Escherichia coli O157:H7 (RIMD 05091083) was produced from the ethanolic extract of Quercus infectoria. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by the agar microdilution method and agar dilution method in petri dishes with millipore filter. Both aqueous and ethanolic extracts of Quercus infectoria and aqueous extract of Punica granatum were highly effective against Escherichia coli O157:H7 with the best MIC and MBC values of 0.09, 0.78, and 0.19, 0.39 mg/ml, respectively. These plant species may provide alternative but bioactive medicines for the treatment of Escherichia coli O157:H7 infection. PMID:15261962

  6. Doxorubicine and antibiotics influence on dynamics of population development of Staphylococcus aureus and Escherichia coli

    Directory of Open Access Journals (Sweden)

    O.G. Shapoval

    2010-03-01

    Full Text Available Infectious complications in oncologic patients often occur as a result of antitumor therapy that demands the prescription of antimicrobic preparations. one of the main infectious agents in oncology is Staphylococci and Escherichia coli. The aim of this work is to study doxorubicine and ceftriaxon influence on dynamics of population development of strains of Staphylococcus aureus, doxorubicine and amikacine - on dynamics of population development of strains of Escherichia coli. Five strains of each type (one-standard and four-clinical cultivated in meatpeptone broth, which contains non-inhibitory concentrations of experimental preparations. in any period of time after the sowing the measurement of optical density of growing cultures has been carried out. it has been determined, that doxorubicine in non-inhibitory concentrations increases overwhelming effect of these antibiotics on dynamics of population development of experimental strains

  7. Cloning and expression of secreted antigens of Clostridium difficile in Escherichia coli.

    OpenAIRE

    Dailey, D C; Schloemer, R H

    1988-01-01

    The feasibility of the cloning and expression of Clostridium difficile antigens in Escherichia coli was investigated. The expression of a limited number of cloned clostridial antigens under the control of clostridial promoter elements in E. coli was observed.

  8. Role of peripheral pooling in porcine Escherichia coli sepsis

    International Nuclear Information System (INIS)

    In anesthesized pigs the effects of E. coli (2 X 10(8)/kg) on hemodynamics and red cell distribution were studied. After injection of 99m-Tc red cells (15 mCi), regional radioactivity was followed during 3 hours. Gated bloodpool studies were performed to measure end-diastolic volumes (EDV). Escherichia coli E. coli was infused in 14 pigs, while 7 animals served as controls. E. coli resulted in an early increase in pulmonary arterial pressure. Systemic arterial pressure decreased gradually, while cardiac output did not change significantly. The gated studies revealed that especially left ventricular end-diastolic volume (LVEDV) declined, to 50% of the basal value. Regional radioactivity did not change over lungs, liver and abdomen. Splenic activity declined markedly. Over the hindlimb a significant increase (29 +/- 8%) was observed. It is concluded that E. coli infusion in pigs induces a hemodynamic pattern similar to human sepsis. The decrease in LVEDV is probably related to peripheral pooling and a change in right ventricle (RV) performance

  9. Phylogenetic analysis of Escherichia coli strains isolated from human samples

    Directory of Open Access Journals (Sweden)

    Abdollah Derakhshandeh

    2013-12-01

    Full Text Available Escherichia coli (E. coli is a normal inhabitant of the gastrointestinal tract of vertebrates, including humans. Phylogenetic analysis has shown that E. coli is composed of four main phylogenetic groups (A, B1, B2 and D. Group A and B1 are generally associated with commensals, whereas group B2 is associated with extra-intestinal pathotypes. Most enteropathogenic isolates, however, are assigned to group D. In the present study, a total of 102 E. coli strains, isolated from human samples, were used. Phylogenetic grouping was done based on the Clermont triplex PCR method using primers targeted at three genetic markers, chuA, yjaA and TspE4.C2. Group A contained the majority of the collected isolates (69 isolates, 67.64%, followed by group B2 (18 isolates, 17.64% and D (15 isolates, 14.7% and no strains were found to belong to group B1. The distribution of phylogenetic groups in our study suggests that although the majority of strains were commensals, the prevalence of enteropathogenic and extra-intestinal pathotypes was noteworthy. Therefore, the role of E. coli in human infections including diarrhea, urinary tract infections and meningitis should be considered.

  10. Selective detection of Escherichia coli DNA using fluorescent carbon spindles.

    Science.gov (United States)

    Roy, Anurag; Chatterjee, Sabyasachi; Pramanik, Srikrishna; Devi, Parukuttyamma Sujatha; Suresh Kumar, Gopinatha

    2016-04-28

    We investigate the interaction of hydrophilic blue emitting carbon spindles with various deoxyribonucleic acids (DNA) having different base pair compositions, such as Herring testes (HT), calf thymus (CT), Escherichia coli (EC) and Micrococcus lysodeikticus (ML) DNA, to understand the mode of interaction. Interestingly, the fluorescent carbon spindles selectively interacted with E. coli DNA resulting in enhanced fluorescence of the former. Interaction of the same carbon with other DNAs exhibited insignificant changes in fluorescence. In addition, in the presence of EC DNA, the D band in the Raman spectrum attributed to the defect state completely disappeared, resulting in enhanced crystallinity. Microscopy images confirmed the wrapping of DNA on the carbon spindles leading to the assembly of spindles in the form of flowers. Dissociation of double-stranded DNA occurred upon interaction with carbon spindles, resulting in selective E. coli DNA interaction. The carbon spindles also exhibited a similar fluorescence enhancement upon treating with E. coli bacteria. These results confirm the possibility of E. coli detection in water and other liquid foods using such fluorescent carbon. PMID:27081680

  11. Escherichia coli out in the cold: Dissemination of human-derived bacteria into the Antarctic microbiome.

    Science.gov (United States)

    Power, Michelle L; Samuel, Angelingifta; Smith, James J; Stark, Jonathon S; Gillings, Michael R; Gordon, David M

    2016-08-01

    Discharge of untreated sewage into Antarctic environments presents a risk of introducing non-native microorganisms, but until now, adverse consequences have not been conclusively identified. Here we show that sewage disposal introduces human derived Escherichia coli carrying mobile genetic elements and virulence traits with the potential to affect the diversity and evolution of native Antarctic microbial communities. We compared E. coli recovered from environmental and animal sources in Antarctica to a reference collection of E. coli from humans and non-Antarctic animals. The distribution of phylogenetic groups and frequency of 11 virulence factors amongst the Antarctic isolates were characteristic of E. coli strains more commonly associated with humans. The rapidly emerging E. coli ST131 and ST95 clones were found amongst the Antarctic isolates, and ST95 was the predominant E. coli recovered from Weddell seals. Class 1 integrons were found in 15% of the Antarctic E. coli with 4 of 5 identified gene cassette arrays containing antibiotic resistance genes matching those common in clinical contexts. Disposing untreated sewage into the Antarctic environment does disseminate non-native microorganisms, but the extent of this impact and implications for Antarctic ecosystem health are, as yet, poorly understood. PMID:27179324

  12. Antibacterial activity of essential oil of north west Algerian Eucalyptus camaldulensis against Escherichia coli and Staphylococcus aureus

    OpenAIRE

    Bachir Raho Ghalem; Benali Mohamed

    2014-01-01

    Objective: To evaluate the in vitro antimicrobial activities of the crude oil of Eucalyptus camaldulensis (E. camaldulensis) leaves. Methods: The essential oils of E. camaldulensis harvested from the garden of the Health Center in Sidi Bel Abbes city (North West of Algeria), were screened for their antibacterial activities against two clinical bacteria [Escherichia coli (E. coli), Staphylococcus aureus (S. aureus)] by the agar disc diffusion method and broth dilution susceptibi...

  13. Cloning and surface expression in Escherichia coli of a structural gene encoding a surface protein of Haemophilus influenzae type b.

    OpenAIRE

    Holmans, P L; Loftus, T A; Hansen, E J

    1985-01-01

    Recombinant DNA technology was used to clone a gene coding for a surface protein of Haemophilus influenzae type b (Hib) into Escherichia coli. Chromosomal DNA from a clinical isolate of Hib was cleaved with EcoRI and ligated into plasmid vectors containing three different translational reading frames. E. coli carrying recombinant plasmids were screened in a colony blot-radioimmunoassay system by using murine monoclonal antibodies (mabs) directed against cell surface-exposed proteins of Hib. m...

  14. Structure and copy number of gene clusters related to the pap P-adhesin operon of uropathogenic Escherichia coli.

    OpenAIRE

    Arthur, M; Campanelli, C; Arbeit, R D; Kim, C.; Steinbach, S; C. E. Johnson; Rubin, R H; Goldstein, R.

    1989-01-01

    The structurally related pap and prs operons of the uropathogenic Escherichia coli isolate J96 encode a P and an F adhesin that mediate bacterial attachment to the human P blood group antigen and the Forssman antigen, respectively. Using probes prepared from different segments of the pap operon, Southern blot hybridizations were performed to characterize pap-related sequences of 30 E. coli clinical isolates expressing different adhesin phenotypes. Gene clusters encoding P and F adhesins displ...

  15. Escherichia coli B lacks one of the two initiator tRNA species present in E. coli K-12.

    OpenAIRE

    Mandal, N; RajBhandary, U L

    1992-01-01

    We show that the metY locus which specifies tRNA(2fMet) in Escherichia coli K-12 specifies tRNA(1fMet) in E. coli B. This conclusion is based on results of Southern blot analysis of E. coli B and K-12 DNAs and on polymerase chain reaction amplification, cloning, and sequencing of an approximately 200-bp region of DNA corresponding to the metY loci of E. coli B and E. coli K-12. We also show that the metY locus of E. coli B is transcriptionally active. E. coli strains transformed with the mult...

  16. Antimicrobial Resistant Pattern of Escherichia Coli Strains Isolated from Pediatric Patients in Jordan

    Directory of Open Access Journals (Sweden)

    Mohammad Alshara

    2011-05-01

    Full Text Available The present study was conducted to investigate antimicrobial resistant pattern of Escherichia coli (E. coli strains isolated from clinical specimens of Jordanian pediatric patients during the period from January to December 2008. A total of 444 E. coli strains were isolated from clinical specimens and tested for their susceptibility to different antimicrobial drugs. Overall, high resistance rate was observed for ampicillin (84%, followed by amoxicillin-clavulanic acid (74.3%, cotrimoxazole (71%, nalidixic acid (47.3%, cephalothin (41%. Lower resistance rates were observed for amikacin (0% followed by Cefotaxime (11%, Ceftriaxone (11.7%, ciprofloxacin (14.5%, Norfloxacin (16.5%, gentamicin (17.3% cephalexin (20.9%, Ceftazidime (22.5%, cefixime (29.6%, and cefaclor (32.8%. Ampicillin, amoxicillin-clavulanic acid and cotrimoxazole were found to be ineffective at in vitro inhibition of the E. coli of pediatric origin. Amikacin was highly effective for E. coli with susceptibility rate of 100%. The majority of E. coli strains were susceptible to third generation cephalosporins and fluoroquinolones.

  17. Antimicrobial Susceptibility Testing for Escherichia coli Strains to Fluoroquinolones, in Urinary Tract Infections

    Directory of Open Access Journals (Sweden)

    FA Nakhjavani

    2007-05-01

    Full Text Available Background: Urinary Tract Infections (UTIs are one of the most common infectious diseases diagnosed all over the world. Meanwhile most episode of UTIs are caused by Escherichia coli (up to 85% and frequently fluoroquinolones are preferred as initial agents for empiric therapy of UTIs. Widespread use of fluoroquinolones has resulted in an increasing incidence of resistance these agents all over the world. The aim of this study was to assess, susceptibility of Escherichia coli strains from UTI patients against common fluoroquinolones. Methods: Antimicrobial susceptibility testing was determined by disk agar diffusion (DAD and Minimal Inhibitory Concentration methods as described by the National Committee for Clinical Laboratory Standards (NCCLS. Results: One hundred sixty four clinical isolates of E. coli were collected by urine cultures from patients with UTI. The extent of resistant to nalidixic acid, ofloxacin, norfloxacin and ciprofloxacin, by disk diffusion method was 49.3%, 44.5%, 41.4% and 40.2%, respectively. Resistance to ciprofloxacin by MIC method was 4.9%. Conclusion: This study represents high level resistant of E. coli isolates from UTI patients. It is because of inappropriate and incorrect administration of antimicrobial agents in blind cases. This problem remarks significance of performing antimicrobial susceptibility testing before empiric antibiotic therapy. To overcome this problem use of unnecessary antibiotics therapy should be limited.

  18. Characterization of Escherichia coli Strains from Cases of Childhood Diarrhea in Provincial Southwestern Nigeria

    OpenAIRE

    Iruka N Okeke; Lamikanra, Adebayo; Steinrück, Hartmut; Kaper, James B.

    2000-01-01

    In a study carried out in small-town and rural primary health care centers in southwestern Nigeria, 330 Escherichia coli strains isolated from 187 children with diarrhea and 144 apparently healthy controls were examined for virulence traits. Based on the results of colony blot hybridization, strains were categorized as enteropathogenic E. coli (1.8%), enterotoxigenic E. coli (2.4%), enteroinvasive E. coli (1.2%), enterohemorrhagic E. coli (0.6%), enteroaggregative E. coli (10.3%), diffusely a...

  19. Viabilidad de Escherichia coli en presencia de diferentes contaminantes

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    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.

  20. Inactivation of Escherichia coli in soil by solarization

    International Nuclear Information System (INIS)

    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)

  1. Overexpression and export of Vibrio anguillarum metalloprotease in Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    Zhang Fengli; Chi Zhenming; Chen Jixiang; Wu Longfei; Liang Likun

    2007-01-01

    Vibrio anguillarum metalloprotease, an extracellular zinc metalloprotease involved in the virulence mechanism of Vibrio anguillarum, is synthesized from the empA gene as a 611-residue precursor and naturally secreted via Sec secretion pathway in Vibrio anguillarum. In this study, heterologous expression of the empA gene encoding metallopmtease and export of the recombinant metalloprotease in Escherichia coliwere examined. The empA gene was subcloned into pBAD24 with arabinose promoter and sequenced. The sequence encoded a polypeptide(611 amino acids)consisting of four domains: a signal peptide, an Nterminal propeptide, a mature region and a C-terminal propeptide. The empA gene inserted in plasmid pBAD24 was overexpressed in TOP10 strain of E. Coli after arabinose induction. The 36kDa polypeptide of the recombinant metalloprotease as the mature protease was further confirmed by SDS-PAGE and immunoblotting. It was found that recombinant metalloprotease with the EmpA activity and antigenicity wasexported into the periplasm of Escherichia coli cells via Sec translocation pathway, whereas it was secreted into extracellular environments in V. Anguillarum. The results imply that the expression, export and processing mechanism of the protein in E. Coli are similar to those in V. Anguillarum.

  2. Widespread antibiotic resistance of diarrheagenic Escherichia coli and Shigella species

    Directory of Open Access Journals (Sweden)

    Azam Fatahi Sadeghabadi

    2014-01-01

    Full Text Available Background: Antibiotic resistance of enteric pathogens particularly Shigella species, is a critical world-wide problem and monitoring their resistant pattern is essential, because the choice of antibiotics is absolutely dependent on regional antibiotic susceptibility patterns. During summer 2013, an unusual increase in number of diarrheal diseases was noticed in Isfahan, a central province of Iran. Therefore, the antibiotic resistance of diarrheagenic Escherichia coli and Shigella species isolated were evaluated. Materials and Methods: According to the guideline on National Surveillance System for Foodborn Diseases, random samples from patients with acute diarrhea were examined in local laboratories of health centers and samples suspicious of Shigella spp. were further assessed in referral laboratory. Isolated pathogens were identified by standard biochemical and serologic tests and antibiotic susceptibility testing was carried out by disc diffusion method. Results: A total of 1086 specimens were obtained and 58 samples suspicious of Shigella were specifically evaluated. The most prevalent isolated pathogen was Shigella sonnei (26/58 followed by E. coli (25/58 and Shigella flexneri (3/58. A large number of isolated bacteria were resistant to co-trimoxazole (Shigella spp: 100%, E. coli: 80%, azithromycin (Shigella spp: 70.4%, E. coli: 44.0%, ceftriaxone (Shigella spp: 88.9%, E. coli: 56.0% and cefixime (Shigella spp: 85.2%, E. coli: 68.0%. About88.3% of S. sonnei isolates, one S. flexneri isolate, and 56% of E. coli strains were resistant to at least three antibiotic classes (multidrug resistant. Conclusion: Due to high levels of resistance to recommended and commonly used antibiotics for diarrhea, continuous monitoring of antibiotic resistance seems essential for determining best options of empirical therapy.

  3. 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.

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

    OpenAIRE

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

    2004-01-01

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

  5. Antimicrobial Activity of Intraurethrally Administered Probiotic Lactobacillus casei in a Murine Model of Escherichia coli Urinary Tract Infection

    OpenAIRE

    Asahara, Takashi; Nomoto, Koji; Watanuki, Masaaki; Yokokura, Teruo

    2001-01-01

    The antimicrobial activity of the intraurethrally administered probiotic Lactobacillus casei strain Shirota against Escherichia coli in a murine urinary tract infection (UTI) model was examined. UTI was induced by intraurethral administration of Escherichia coli strain HU-1 (a clinical isolate from a UTI patient, positive for type 1 and P fimbriae), at a dose of 1 × 106 to 2 × 106 CFU in 20 μl of saline, into a C3H/HeN mouse bladder which had been traumatized with 0.1 N HCl followed immediate...

  6. Analysis of clinical distribution and drug-resistant trend of Escherichia coli from 2008 to 2012%2008-2012年大肠埃希菌临床分布及耐药趋势分析

    Institute of Scientific and Technical Information of China (English)

    张翠英; 栗志平; 李菊平; 杨妮娜; 赵芳

    2013-01-01

    目的 研究长治市第二人医院2008年至2012年大肠埃希菌的临床分布特点及对常用抗菌药物的耐药趋势变化,为临床预防和控制大肠埃希菌感染提供依据.方法 对5年间从临床各种标本中分离的大肠埃希菌进行回顾性分析,菌株鉴定采用API及ATB鉴定仪,采用CLSI推荐的K-B法进行药敏试验和折点判读.ESBLs确证试验采用双纸片法.结果 共分离大肠埃希菌804株,其中产ESBLs 344株,占42.79%.804株大肠埃希菌中来自尿液标本426株,占52.99%;疫标本135株,占16.79%;脓和分泌物132株,占16.42%;血液标本39株,占4.85%.大肠埃希菌对左氧氟沙星、头孢唑啉、头孢呋辛、庆大霉素、妥布霉素的耐药率较高(>50%),且对左氧氟沙星的耐药率呈逐年上升趋势;对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、阿米卡星、呋喃妥因的耐药率较低(<10%);对亚胺培南的耐药率为0.结论 大肠埃希菌的检出率及其对多种抗生素的耐药率维持在较高水平,应根据药敏结果,合理应用抗菌药物,预防耐药菌的产生.%Objective To study E.coli clinical distribution characteristics and drug resistance to commonly used antimicrobial agents trend change in the second people' s hospital of Changzhi from 2008 to 2012,in order to provide the basis for clinical prevention and control of E.coli infection.Methods All kinds of E.coli isolated from clinical specimens in five years were retrospectively analyzed.API and ATB bacteria identification instrument were used for bacterial strains identification.K-B method recommended by CLSI was used for drug sensitive test and fold point interpretation.ESBLs was confirmed with double slip of paper method.Results A total of 804 strains of E.coli had been separated.There were 344 ESBLs-producing strains,accounting for 42.79%.Among the 804 strains of E.coli,426 strains were isolated from urine,accounting for 52.99% ; 135 strains from sputum

  7. In vitro inhibition of adhesion of Escherichia coli strains by Xylitol

    Directory of Open Access Journals (Sweden)

    Annelisa Farah da Silva

    2011-04-01

    Full Text Available The present study aimed to evaluate xylitol's antimicrobial and anti-adherence activities on Escherichia coli (ATCC 8739 and on another clinical strain enteropathogenic E. coli (EPEC. In vitro minimum inhibitory concentration (MIC test and adhesion assays were performed using 0.5, 2.5 and 5.0% xylitol. It was found that xylitol did not have antimicrobial properties on these strains. The scanning electron microscopy (SEM demonstrated that the slides treated with xylitol had a significant reduction in the number of bacilli and the inhibition of microbial adhesion was probably the xylitol's mechanism of action. Xylitol could be a possible alternative on the control of E. coli infections.

  8. Type 1 fimbrial expression enhances Escherichia coli virulence for the urinary tract

    DEFF Research Database (Denmark)

    Connell, Hugh; Agace, William; Klemm, Per; Schembri, Mark; Mårild, Stefan; Svanborg, Catharina

    1996-01-01

    Type 1 fimbriae are adhesion organelles expressed by many Gram-negative bacteria. They facilitate adherence to mucosal surfaces and inflamatory cells in vitro, but their contribution to virulence has not been defined. This study present evidence that type 1 fimbriae increase the virulence of...... Escherichia coli for the urinary tract by promoting bacterial persistence and enhancing the inflammatory responce to infection. In a clinical study, we observed that disease severity was greater in children infected with E. coli O1:K1:H7 isolates expressing type 1 fimbriae than in those infected with type 1...... numbers, and induced a greater neutrophil influx into the urine, than O1:K1:H7 type 1-negative isolates. To confirm a role of type 1 fimbriae, a fimH null mutant (CN1016) was constructed from an O1:K1:H7 type 1 positive parent. E. coli CN1016 had reduced survival and inflammatogenicity in the mouse...

  9. Total biosynthesis of opiates by stepwise fermentation using engineered Escherichia coli

    Science.gov (United States)

    Nakagawa, Akira; Matsumura, Eitaro; Koyanagi, Takashi; Katayama, Takane; Kawano, Noriaki; Yoshimatsu, Kayo; Yamamoto, Kenji; Kumagai, Hidehiko; Sato, Fumihiko; Minami, Hiromichi

    2016-01-01

    Opiates such as morphine and codeine are mainly obtained by extraction from opium poppies. Fermentative opiate production in microbes has also been investigated, and complete biosynthesis of opiates from a simple carbon source has recently been accomplished in yeast. Here we demonstrate that Escherichia coli serves as an efficient, robust and flexible platform for total opiate synthesis. Thebaine, the most important raw material in opioid preparations, is produced by stepwise culture of four engineered strains at yields of 2.1 mg l−1 from glycerol, corresponding to a 300-fold increase from recently developed yeast systems. This improvement is presumably due to strong activity of enzymes related to thebaine synthesis from (R)-reticuline in E. coli. Furthermore, by adding two genes to the thebaine production system, we demonstrate the biosynthesis of hydrocodone, a clinically important opioid. Improvements in opiate production in this E. coli system represent a major step towards the development of alternative opiate production systems. PMID:26847395

  10. Fator necrosante citotóxico em Escherichia coli isolada de mastite clínica bovina

    Directory of Open Access Journals (Sweden)

    Ribeiro M.G.

    2002-01-01

    Full Text Available This report describes the production of cytotoxic necrotizing factor (CNF by an Escherichia coli strain isolated from clinical bovine mastitis with clinical signs of toxemia The animal had hemorrhages and necrosis of the mammary glands, and died within 24 hours after the onset of clinical signs. In addition to CNF identification, alpha-haemolysin and siderophores production were also characterized in this strain. This report reinforce the association of CNF and alpha-haemolysin production in E. coli virulence associated with clinical cases of severe bovine mastitis.

  11. Binding of Escherichia coli S fimbriae to human kidney epithelium

    OpenAIRE

    Korhonen, T K; Parkkinen, J; Hacker, Jörg; Finne, J; Pere, A; Rhen, M; Holthöfer, H

    2011-01-01

    Purified S fimbriae and an Escherichia coli strain carrying the recombinant plasmid pANN801-4 that encodes S fimbriae were tested for adhesion to frozen sections of human kidney. The fimbriae and the bacteria bound to the same tissue domains, and in both cases the binding was specifically inhibited by the receptor analog of S fimbria, sialyl(alpha 2-3)lactose. S fimbriae bound specifically to the epithelial elements in the kidneys; to the epithelial cells of proximal and distal tubules as wel...

  12. Characterization of RNA damage under oxidative stress in Escherichia coli

    OpenAIRE

    Liu, Min; Gong, Xin; Alluri, Ravi Kumar; Wu, Jinhua; Sablo, Tene’; Li, Zhongwei

    2012-01-01

    We have examined the level of 8-hydroxyguanosine (8-oxo-G), an oxidized form of guanosine, in RNA in Escherichia coli under normal and oxidative stress conditions. The level of 8-oxo-G in RNA rises rapidly and remains high for hours in response to hydrogen peroxide (H2O2) challenge in a dose-dependent manner. H2O2 induced elevation of 8-oxo-G content is much higher in RNA than that of 8-hydroxydeoxyguanosine (8-oxo-dG) in DNA. Under normal conditions, the 8-oxo-G level is low in RNA isolated ...

  13. Effect of Zinc in Enteropathogenic Escherichia coli Infection▿ †

    OpenAIRE

    Crane, John K.; Naeher, Tonniele M.; Shulgina, Irina; Zhu, Chengru; Boedeker, Edgar C.

    2007-01-01

    Enteropathogenic Escherichia coli (EPEC) infection triggers the release of ATP from host intestinal cells, and the ATP is broken down to ADP, AMP, and adenosine in the lumen of the intestine. Ecto-5′-nucleotidase (CD73) is the main enzyme responsible for the conversion of 5′-AMP to adenosine, which triggers fluid secretion from host intestinal cells and also has growth-promoting effects on EPEC bacteria. In a recent study, we examined the role of the host enzyme CD73 in EPEC infection by test...

  14. Replication initiation at the Escherichia coli chromosomal origin

    OpenAIRE

    Kaguni, Jon M.

    2011-01-01

    To initiate DNA replication, DnaA recognizes and binds to specific sequences within the Escherichia coli chromosomal origin (oriC), and then unwinds a region within oriC. Next, DnaA interacts with DnaB helicase in loading the DnaB-DnaC complex on each separated strand. Primer formation by primase (DnaG) induces the dissociation of DnaC from DnaB, which involves the hydrolysis of ATP bound to DnaC. Recent evidence indicates that DnaC acts as a checkpoint in the transition from initiation to th...

  15. Tetrahydrothiophene 1-oxide as an electron acceptor for Escherichia coli.

    OpenAIRE

    Meganathan, R; Schrementi, J

    1987-01-01

    Escherichia coli used tetrahydrothiophene 1-oxide (THTO) as an electron acceptor for anaerobic growth with glycerol as a carbon source; the THTO was reduced to tetrahydrothiophene. Cell extracts also reduced THTO to tetrahydrothiophene in the presence of a variety of electron donors. Chlorate-resistant (chl) mutants (chlA, chlB, chlD, and chlE) were unable to grow with THTO as the electron acceptor. However, growth and THTO reduction by the chlD mutant were restored by high concentrations of ...

  16. Multiple joined genes prevent product degradation in Escherichia coli.

    OpenAIRE

    Shen, S H

    1984-01-01

    A method is described that allows the expression of a stable human proinsulin product in Escherichia coli as encoded by either a fused or an unfused gene construction. In the fused system, the human proinsulin coding sequence is joined to the 3' side of a fragment containing the lac promoter and the coding sequence for a small part of the NH2 terminus of beta-galactosidase. In the unfused system, the proinsulin coding sequence is linked directly to a fragment containing the Tac promoter follo...

  17. Carbon and energy metabolism of atp mutants of Escherichia coli

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Michelsen, Ole

    1992-01-01

    The membrane-bound H+-ATPase plays a key role in free-energy transduction of biological systems. We report how the carbon and energy metabolism of Escherichia coli changes in response to deletion of the atp operon that encodes this enzyme. Compared with the isogenic wild-type strain, the growth...... rate and growth yield were decreased less than expected for a shift from oxidative phosphorylation to glycolysis alone as a source of ATP. Moreover, the respiration rate of a atp deletion strain was increased by 40% compared with the wild-type strain. This result is surprising, since the atp deletion...

  18. Transcriptional Response of Escherichia coli to External Zinc

    OpenAIRE

    Yamamoto, Kaneyoshi; Ishihama, Akira

    2005-01-01

    Transcriptional response of Escherichia coli to extracellular zinc was studied using DNA microarray and S1 mapping assays. Addition of external zinc induced the expression of zinc exporter ZntA and inhibited the expression of zinc importer ZnuC. In the continuous presence of zinc, ZnuC repression took place at lower zinc concentrations than ZntA induction. The microarray assay indicated that the addition of excess external zinc induces the expression of many genes that are organized in the re...

  19. Rapid test for assay of ozone sensitivity in Escherichia coli

    International Nuclear Information System (INIS)

    A rapid test devised for assay of ozone sensitivity in Escherichia coli based on the procedure used by Chung and Greenberg (1968) for assay of radiation sensitivity is described. The detection of new mutants, either more resistant or more sensitive than wild type strain to ozone, and the genetic analysis of ozone recombinants are now possible. Results confirm that ozone resistance is probably involved with DNA repair mechanisms; and show that ozone and ultraviolet light inhibit the cell division capacity of lon mutants in a similar way. (orig.)

  20. Dual genetic selection of synthetic riboswitches in Escherichia coli.

    Science.gov (United States)

    Nomura, Yoko; Yokobayashi, Yohei

    2014-01-01

    This chapter describes a genetic selection strategy to engineer synthetic riboswitches that can chemically regulate gene expression in Escherichia coli. Riboswitch libraries are constructed by randomizing the nucleotides that potentially comprise an expression platform and fused to the hybrid selection/screening marker tetA-gfpuv. Iterative ON and OFF selections are performed under appropriate conditions that favor the survival or the growth of the cells harboring the desired riboswitches. After the selection, rapid screening of individual riboswitch clones is performed by measuring GFPuv fluorescence without subcloning. This optimized dual genetic selection strategy can be used to rapidly develop synthetic riboswitches without detailed computational design or structural knowledge. PMID:24549616

  1. Identification, Expression, and Characterization of Escherichia coli Guanine Deaminase

    OpenAIRE

    Maynes, Jason T.; Yuan, Richard G.; Snyder, Floyd F.

    2000-01-01

    Using the human cDNA sequence corresponding to guanine deaminase, the Escherichia coli genome was scanned using the Basic Local Alignment Search Tool (BLAST), and a corresponding 439-residue open reading frame of unknown function was identified as having 36% identity to the human protein. The putative gene was amplified, subcloned into the pMAL-c2 vector, expressed, purified, and characterized enzymatically. The 50.2-kDa protein catalyzed the conversion of guanine to xanthine, having a Km of ...

  2. Modulation of allele leakiness and adaptive mutability in Escherichia coli

    Indian Academy of Sciences (India)

    R. Jayaraman

    2000-08-01

    It is shown that partial phenotypic suppression of two ochre mutations (argE3 and lacZU118) and an amber mutation (in argE) by sublethal concentrations of streptomycin in an rpsL+ (streptomycin-sensitive) derivative of the Escherichia coli strain AB1157 greatly enhances their adaptive mutability under selection. Streptomycin also increases adaptive mutability brought about by the ppm mutation described earlier. Inactivation of recA affects neither phenotypic suppression by streptomycin nor replication-associated mutagenesis but abolishes adaptive mutagenesis. These results indicate a causal relationship between allele leakiness and adaptive mutability.

  3. relA-dependent RNA polymerase activity in Escherichia coli.

    OpenAIRE

    Ryals, J; Bremer, H

    1982-01-01

    Parameters relating to RNA synthesis were measured after a temperature shift from 30 to 42 degrees C, in a relA+ and relA- isogenic pair of Escherichia coli strains containing a temperature-sensitive valyl tRNA synthetase. The following results were obtained: (i) the rRNA chain growth rate increased 2-fold in both strains; (ii) newly synthesized rRNA became unstable in both strains; (iii) the stable RNA gene activity (rRNA and tRNA, measured as stable RNA synthesis rate relative to the total ...

  4. The action of beta-galactosidase (Escherichia coli) on allolactose.

    Science.gov (United States)

    Huber, R E; Wallenfels, K; Kurz, G

    1975-09-01

    The parameters involved in the action of beta-galactosidase (EC 3.2.1.23) (Escherichia coli) on allolactose, the natural inducer of lac operon in E. coli, were studied. At low allolactose concentrations only galactose and glucose were formed, while at high allolactose concentrations transgalactolytic oligosaccharides were also produced. Detectable amounts of lactose were not formed. The V and Km values (49.6 U/mg and 0.00120 M, respectively) indicated that allolactose is as good if not a better substrate of beta-galactosidase as lactose. The pH optimum with allolactose (7.8-7.9) as well as its activation by K+ (as compared to activation by Na+) were similar to the case with lactose as substrate. The alpha-anomer of allolactose was hydrolyzed about two times as rapidly as was the beta-anomer. PMID:241475

  5. Antimicrobial activity of peptidomimetics against multidrug-resistant Escherichia coli

    DEFF Research Database (Denmark)

    Jahnsen, Rasmus D; Frimodt-Møller, Niels; Franzyk, Henrik

    2012-01-01

    Novel remedies in the battle against multidrug-resistant bacterial strains are urgently needed, and one obvious approach involves antimicrobial peptides and mimics hereof. The impact of a- and ß-peptoid as well as ß(3)-amino acid modifications on the activity profile against ß......-lactamase-producing Escherichia coli was assessed by testing an array comprising different types of cationic peptidomimetics obtained by a general monomer-based solid-phase synthesis protocol. Most of the peptidomimetics possessed high to moderate activity toward multidrug-resistant E. coli as opposed to the corresponding...... inactive peptides. Nevertheless, differences in hemolytic activities indicate that a careful choice of backbone design constitutes a significant parameter in the search for effective cationic antimicrobial peptidomimetics targeting specific bacteria....

  6. Human Insulin Modulation of Escherichia coli Adherence and Chemotaxis

    Directory of Open Access Journals (Sweden)

    Karolina Klosowska

    2006-01-01

    Full Text Available Escherichia coli exhibited increased hydrophobicity and mannose-resistant epithelial cell adherence after growth in the presence of human insulin (2 µU mLˉ1 or 200 µUmLˉ1 insulin, respectively with glucose (100 mg dLˉ1. Capsule production and hemagglutination were unaffected by insulin and glucose. Chemotactic attraction to glucose as compared to insulin or glucose alone was enhanced by the presence of insulin. Insulin alone (200 µU mLˉ1 was a chemorepellent and inhibited flagellar tethering to glass. These findings indicate that human insulin can modulate E. coli’s expression of factors associated with pathogenesis in a manner that is modifiable by the presence of glucose.

  7. Engineering Escherichia coli Cell Factories for n-Butanol Production.

    Science.gov (United States)

    Dong, Hongjun; Zhao, Chunhua; Zhang, Tianrui; Lin, Zhao; Li, Yin; Zhang, Yanping

    2016-01-01

    The production of n-butanol, as a widely applied solvent and potential fuel, is attracting much attention. The fermentative production of butanol coupled with the production of acetone and ethanol by Clostridium (ABE fermentation) was once one of the oldest biotechnological processes, ranking second in scale behind ethanol fermentation. However, there remain problems with butanol production by Clostridium, especially the difficulty in genetically manipulating clostridial strains. In recent years, many efforts have been made to produce butanol using non-native strains. Until now, the most advanced effort was the engineering of the user-friendly and widely studied Escherichia coli for butanol production. This paper reviews the current progress and problems relating to butanol production by engineered E. coli in terms of prediction using mathematical models, pathway construction, novel enzyme replacement, butanol toxicity, and tolerance engineering strategies. PMID:25662903

  8. Impact of cranberry on Escherichia coli cellular surface characteristics

    International Nuclear Information System (INIS)

    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.

  9. Sickness behavior in dairy cows during Escherichia coli mastitis

    DEFF Research Database (Denmark)

    Fogsgaard, Katrine Kop; Røntved, Christine Maria; Sørensen, Peter;

    2012-01-01

    -recorded on 5 consecutive days, d −2 to +2 after challenge when the cows were not disturbed by humans. The behavior of the animals was compared among all days. Infection with E. coli altered the behavior of the dairy cows. Time spent feeding was lower in the initial 24 h after infection compared with that on......The consequences of mastitis in terms of dairy cow behavior are relatively unknown. Future assessment of dairy cow welfare during mastitis will be facilitated by knowledge about the potential of mastitis to induce sickness behavior. Our aim was to examine behavior of dairy cows in the period from 2...... d before (d −2 and −1) to 3 d (d 0, 1, and 2) after experimental intramammary challenge with Escherichia coli. Effects of experimentally induced mastitis on behavior were examined in 20 primiparous Danish Holstein-Friesian cows, all 3 to 6 wk after calving and kept in tie stalls. After evening...

  10. Assessment of Escherichia coli isolates for In vitro biofilm production

    Directory of Open Access Journals (Sweden)

    A.I. Dadawala

    Full Text Available A total of 14 Escherichia coli isolates were assessed for their ability to produce biofilm in-vitro by slime production on Congo red agar medium (CRA and microtitre plate assay. Out of 14 isolates tested, 12 were slime producing on CRA as indicated by black colonies. The isolates of E.coli varied in their ability to produce biofilm on the surface of microtitre plate ranging from 0.101 to 0.543 ODm. Out of 14 isolates tested, 10 were positive for biofilm production employing criterion of blank corrected ODs9s > 0.1. Two of slime negative isolated were also negative for biofilm production where as the two slime positive isolates were found to be negative for biofilm production. [Veterinary World 2010; 3(8.000: 364-366

  11. Metabolite essentiality elucidates robustness of Escherichia coli metabolism

    CERN Document Server

    Kim, Pan-Jun; Kim, Tae Yong; Lee, Kwang Ho; Jeong, Hawoong; Lee, Sang Yup; Park, Sunwon

    2007-01-01

    Complex biological systems are very robust to genetic and environmental changes at all levels of organization. Many biological functions of Escherichia coli metabolism can be sustained against single-gene or even multiple-gene mutations by using redundant or alternative pathways. Thus, only a limited number of genes have been identified to be lethal to the cell. In this regard, the reaction-centric gene deletion study has a limitation in understanding the metabolic robustness. Here, we report the use of flux-sum, which is the summation of all incoming or outgoing fluxes around a particular metabolite under pseudo-steady state conditions, as a good conserved property for elucidating such robustness of E. coli from the metabolite point of view. The functional behavior, as well as the structural and evolutionary properties of metabolites essential to the cell survival, was investigated by means of a constraints-based flux analysis under perturbed conditions. The essential metabolites are capable of maintaining a...

  12. In Vivo study of naturally deformed Escherichia coli bacteria.

    Science.gov (United States)

    Tavaddod, Sharareh; Naderi-Manesh, Hossein

    2016-06-01

    A combination of light-microscopy and image processing has been applied to study naturally deformed Escherichia coli under in vivo condition and at the order of sub-pixel high-resolution accuracy. To classify deflagellated non-dividing E. coli cells to the rod-shape and bent-shape, a geometrical approach has been applied. From the analysis of the geometrical data which were obtained of image processing, we estimated the required effective energy for shaping a rod-shape to a bent-shape with the same size. We evaluated the energy of deformation in the naturally deformed bacteria with minimum cell manipulation, under in vivo condition, and with minimum influence of any external force, torque and pressure. Finally, we have also elaborated on the possible scenario to explain how naturally deformed bacteria are formed from initial to final-stage. PMID:27026097

  13. Antimicrobial resistance of Escherichia coli isolates from canine urinary tract infections.

    Science.gov (United States)

    Chang, Shao-Kuang; Lo, Dan-Yuan; Wei, Hen-Wei; Kuo, Hung-Chih

    2015-01-01

    This study determined the antimicrobial resistance profiles of Escherichia coli isolates from dogs with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 201 dogs with UTI diagnosed through clinical examination and urinalysis were processed for isolation of Escherichia coli. Colonies from pure cultures were identified by biochemical reactions (n=114) and were tested for susceptibility to 18 antimicrobials. The two most frequent antimicrobials showing resistance in Urinary E. coli isolates were oxytetracycline and ampicillin. Among the resistant isolates, 17 resistance patterns were observed, with 12 patterns involving multidrug resistance (MDR). Of the 69 tetracycline-resistant E. coli isolates, tet(B) was the predominant resistance determinant and was detected in 50.9% of the isolates, whereas the remaining 25.5% isolates carried the tet(A) determinant. Most ampicillin and/or amoxicillin-resistant E. coli isolates carried blaTEM-1 genes. Class 1 integrons were prevalent (28.9%) and contained previously described gene cassettes that are implicated primarily in resistance to aminoglycosides and trimethoprim (dfrA1, dfrA17-aadA5). Of the 44 quinolone-resistant E. coli isolates, 38 were resistant to nalidixic acid, and 6 were resistant to nalidixic acid, ciprofloxacin and enrofloxacin. Chromosomal point mutations were found in the GyrA (Ser83Leu) and ParC (Ser80Ile) genes. Furthermore, the aminoglycoside resistance gene aacC2, the chloramphenicol resistant gene cmlA and the florfenicol resistant gene floR were also identified. This study revealed an alarming rate of antimicrobial resistance among E. coli isolates from dogs with UTIs. PMID:25720807

  14. Deactivation of Escherichia coli by the plasma needle

    Energy Technology Data Exchange (ETDEWEB)

    Sladek, R E J; Stoffels, E [Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2005-06-07

    In this paper we present a parameter study on deactivation of Escherichia coli (E. coli) by means of a non-thermal plasma (plasma needle). The plasma needle is a small-sized (1 mm) atmospheric glow sustained by radio-frequency excitation. This plasma will be used to disinfect heat-sensitive objects; one of the intended applications is in vivo deactivation of dental bacteria: destruction of plaque and treatment of caries. We use E. coli films plated on agar dishes as a model system to optimize the conditions for bacterial destruction. Plasma power, treatment time and needle-to-sample distance are varied. Plasma treatment of E. coli films results in formation of a bacteria-free void with a size up to 12 mm. 10{sup 4}-10{sup 5} colony forming units are already destroyed after 10 s of treatment. Prolongation of treatment time and usage of high powers do not significantly improve the destruction efficiency: short exposure at low plasma power is sufficient. Furthermore, we study the effects of temperature increase on the survival of E. coli and compare it with thermal effects of the plasma. The population of E. coli heated in a warm water bath starts to decrease at temperatures above 40 deg. C. Sample temperature during plasma treatment has been monitored. The temperature can reach up to 60 deg. C at high plasma powers and short needle-to-sample distances. However, thermal effects cannot account for bacterial destruction at low power conditions. For safe and efficient in vivo disinfection, the sample temperature should be kept low. Thus, plasma power and treatment time should not exceed 150 mW and 60 s, respectively.

  15. Deactivation of Escherichia coli by the plasma needle

    International Nuclear Information System (INIS)

    In this paper we present a parameter study on deactivation of Escherichia coli (E. coli) by means of a non-thermal plasma (plasma needle). The plasma needle is a small-sized (1 mm) atmospheric glow sustained by radio-frequency excitation. This plasma will be used to disinfect heat-sensitive objects; one of the intended applications is in vivo deactivation of dental bacteria: destruction of plaque and treatment of caries. We use E. coli films plated on agar dishes as a model system to optimize the conditions for bacterial destruction. Plasma power, treatment time and needle-to-sample distance are varied. Plasma treatment of E. coli films results in formation of a bacteria-free void with a size up to 12 mm. 104-105 colony forming units are already destroyed after 10 s of treatment. Prolongation of treatment time and usage of high powers do not significantly improve the destruction efficiency: short exposure at low plasma power is sufficient. Furthermore, we study the effects of temperature increase on the survival of E. coli and compare it with thermal effects of the plasma. The population of E. coli heated in a warm water bath starts to decrease at temperatures above 40 deg. C. Sample temperature during plasma treatment has been monitored. The temperature can reach up to 60 deg. C at high plasma powers and short needle-to-sample distances. However, thermal effects cannot account for bacterial destruction at low power conditions. For safe and efficient in vivo disinfection, the sample temperature should be kept low. Thus, plasma power and treatment time should not exceed 150 mW and 60 s, respectively

  16. Longitudinal characterization of Escherichia coli in healthy captive nonhuman primates

    Directory of Open Access Journals (Sweden)

    Jonathan B Clayton

    2014-11-01

    Full Text Available The gastrointestinal (GI tracts of nonhuman primates are well known to harbor Escherichia coli, a known commensal of humans and animals. While E. coli is a normal inhabitant of the mammalian gut, it also exists in a number of pathogenic forms or pathotypes, including those with predisposition for the GI tract, as well the urogenital tract. Diarrhea in captive nonhuman primates (NHPs has long been a problem in both zoo settings and research colonies, including the Como Zoo. It is an animal welfare concern, as well as a public health concern. E. coli has not been extensively studied in correlation with diarrhea in captive primates; therefore, a study was performed during the summer of 2009 in collaboration with a zoo in Saint Paul, MN, which was experiencing an increased incidence and severity of diarrhea among their NHP collection. Fresh fecal samples were collected weekly from each member of the primate collection, between June and August of 2009, and E. coli were isolated. A total of 33 individuals were included in the study, representing eight species. E. coli isolates were examined for their genetic relatedness, phylogenetic relationships, plasmid replicon types, virulence gene profiles, and antimicrobial susceptibility profiles. A number of isolates were identified containing virulence genes commonly found in several different E. coli pathotypes, and there was evidence of clonal transmission of isolates between animals and over time. Overall, the manifestation of chronic diarrhea in the Como Zoo primate collection is a complex problem whose solution will require regular screening for microbial agents and consideration of environmental causes. This study provides some insight towards the sharing of enteric bacteria between such animals.

  17. ASSOCIATION OF ESCHERICHIA COLI WITH THE PREVALENCE OF FLIES POPULATION

    Directory of Open Access Journals (Sweden)

    Hassan Flayiah Hassan

    2013-01-01

    Full Text Available Mass releases of house fly Musca domestica (L and stable fly Stomoxys calcitrans (L. Produced by manure piles accumulated nearby horse stables and dairy farm village in Abu-Graib provide continuous threat to inhabitants west of Baghdad. Timing of fly’s mass release in association with the presence of Escherichia coli in manure piles was examined at these locations. Experimental result indicated that flies survived during cold period of December and January in form of larvae deep in manure piles where temperature was around 15-17°C. Once the population of fly’s larvae started to increase by the second week of February, the concentration of E. coli was up to 80×106 CFU mL-1 in manure suspension. Later when larval population reached to a maximum number by the last week of April, the concentration of E. coli in manure sample dropped down to 38×102 CFU mL-1. Similar trend was observed with the proportion of E. coli to general bacteria present in manure samples where the percent decreased from 89% in early season to 1.5% when maximum number of larvae was recorded. The correlation coefficient (R between the number of larvae and coli form bacteria was = -0.73657. These results suggest the association of larval development with the consumption of E. coli. Thus manipulation of bacterial community in manure piles may lead to possible eradication of fly’s seasonal release.

  18. Modification of Artificial Oliogosaccharides in Recombinant Escherichia coli Cells

    Directory of Open Access Journals (Sweden)

    Tomohisa Kato

    2008-01-01

    Full Text Available Artificial oligosaccharides were modified using recombinant Escherichia coli cells that overexpress sialidase. Based on the principle of the saccharide primer method by using bacterial cells overexpressing enzymes related to oligosaccharide modification. Problem statement: It is very hard to obtain oligosaccharides, because they have complex and diverse structures with different linkage patterns and monosaccharide components. Approach: It has been known that various oligosaccharides can be synthesized in mammalian cells from saccharide primers. We attempted to modify oligosaccharides by using bacterial cells overexpressing enzymes related to oligosaccharide modification instead of mammalian cells. Results: The glycosphingolipid-like derivative GM3 was absorbed by the cell and desialylated by the expressed sialidase and the desialylated product was then secreted into the medium. The GM3-type oligosaccharides were not detected from the cell fraction of recombinant E. coli cells that overexpress sialidase differently from recombinant E. coli carrying only vector DNA (pET-19b. Conclusion/Recommendations: E. coli as well as mammalian cells may be used as a biocatalyst for oligosaccharide modification and production of artificial functional oligosaccharides.

  19. Modeling Escherichia coli removal in constructed wetlands under pulse loading.

    Science.gov (United States)

    Hamaamin, Yaseen A; Adhikari, Umesh; Nejadhashemi, A Pouyan; Harrigan, Timothy; Reinhold, Dawn M

    2014-03-01

    Manure-borne pathogens are a threat to water quality and have resulted in disease outbreaks globally. Land application of livestock manure to croplands may result in pathogen transport through surface runoff and tile drains, eventually entering water bodies such as rivers and wetlands. The goal of this study was to develop a robust model for estimating the pathogen removal in surface flow wetlands under pulse loading conditions. A new modeling approach was used to describe Escherichia coli removal in pulse-loaded constructed wetlands using adaptive neuro-fuzzy inference systems (ANFIS). Several ANFIS models were developed and validated using experimental data under pulse loading over two seasons (winter and summer). In addition to ANFIS, a mechanistic fecal coliform removal model was validated using the same sets of experimental data. The results showed that the ANFIS model significantly improved the ability to describe the dynamics of E. coli removal under pulse loading. The mechanistic model performed poorly as demonstrated by lower coefficient of determination and higher root mean squared error compared to the ANFIS models. The E. coli concentrations corresponding to the inflection points on the tracer study were keys to improving the predictability of the E. coli removal model. PMID:24231031

  20. REVIEW VIRULENCE NATURE OF Escherichia coli IN NEONATAL SWINE

    Directory of Open Access Journals (Sweden)

    Nwiyi PAUL

    2015-11-01

    Full Text Available Piglet disease due to Enterotoxigenic Escherichia coli (ETEC are classical and associated typically with severe watery diarrhea within the first two weeks of life and occasionally some days after weaning in pigs. E.coli is a well-known and diverse organism though normally harmless commensal, but when it acquires mobile genetic elements becomes a highly pathogenic organism capable of causing a range of diseases. ETEC adhere to the small intestinal microvilli without inducing morphological lesions and produce enterotoxins acting locally on enterocytes. This leads to hyper-secretions and reduced absorption of electrolytes. The virulence attributes of ETEC are adhesions and toxins and the successful management of the disease is dependent on good understanding of these virulence factors. In pigs ETEC, the commonest adhesions are the fimbriae on the surface K88, K99, 987p, F18ab and F18ac. The enterotoxine of pigs ETEC are further classified into heat-labile (LT and heat-stable (ST. Other subdivisions of enterotoxin E. coli are LT, STb, STa, Stx2e. The adhesive fimbriae and enterotoxins of piglet ETEC can be evaluated using plasmids. Polymerase chain reaction (PCR is a specific test and had been used for virulence gene detection of ETEC. In this reviews, we focus on current opinions and knowledge of the various pathogenic pathways that E.coli uses to cause disease in piglet.

  1. Persistence of colicinogenic Escherichia coli in the mouse gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Giladi Itamar

    2009-08-01

    Full Text Available Abstract Background The ability of a bacterial strain to competitively exclude or displace other strains can be attributed to the production of narrow spectrum antimicrobials, the bacteriocins. In an attempt to evaluate the importance of bacteriocin production for Escherichia coli strain residence in the gastrointestinal tract, a murine model experimental evolution study was undertaken. Results Six colicin-producing, yet otherwise isogenic, E. coli strains were administered and established in the large intestine of streptomycin-treated mice. The strains' persistence, population density, and doubling time were monitored over a period of 112 days. Early in the experiment only minor differences in population density between the various colicin-producing and the non-producing control strains were detected. However, over time, the density of the control strains plummeted, while that of the colicin-producing strains remained significantly higher (F(7,66 = 2.317; P Conclusion The data presented here support prior claims that bacteriocin production may play a significant role in the colonization of E. coli in the gastrointestinal tract. Further, this study suggests that the ability to produce bacteriocins may prove to be a critical factor in determining the success of establishing probiotic E. coli in the gastrointestinal tract of humans and animals.

  2. Survey of microbial contamination and characterization of Escherichia coli in kiwifruit orchards in Shaanxi, China, 2013.

    Science.gov (United States)

    Feng, Yuqing; Yang, Qinnan; Wang, Lingfang; Li, Guanghui; Lv, Xiaoying; Han, Qi'an; Liu, Xiaobo; Xia, Xiaodong

    2015-10-01

    The aim of the study was to survey three foodborne pathogens in kiwifruit orchards as a continuous monitoring program. A total of 193 samples were collected from 11 kiwifruit orchards in Shaanxi province in October 2013. Among the 193 samples, 68 Escherichia coli isolates were recovered, while no Staphylococcus aureus and Salmonella was recovered. All E. coli isolates were characterized by antimicrobial susceptibility testing, detection of virulence genes, and the ability to produce biofilm formation. The isolates were further examined by random amplified polymorphic DNA (RAPD) analysis. E. coli isolates displayed resistance most frequently to tetracycline (48.5%). Two E. coli isolates (2.9%) were positive for the eae gene (the intimin gene). All E. coli isolates lacked the ability to make biofilm formation. Multilocus sequence typing analysis demonstrated that one isolate in kiwifruit orchards shared the same sequence type with a human clinical isolate. RAPD results showed a close relationship among E. coli isolates from fresh fruit, fallen fruit, soil, air, and irrigation water. This study could provide a further understanding of microbial contamination in kiwifruit orchards based on our previous study and help growers take appropriate measures for prevention. PMID:26267480

  3. 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.

  4. Mild gut inflammation modulates the proteome of intestinal Escherichia coli.

    Science.gov (United States)

    Schumann, Sara; Alpert, Carl; Engst, Wolfram; Klopfleisch, Robert; Loh, Gunnar; Bleich, André; Blaut, Michael

    2014-09-01

    Using interleukin 10-deficient (IL-10(-/-) ) and wild-type mice monoassociated with either the adherent-invasive Escherichia coli UNC or the probiotic E. coli Nissle, the effect of a mild intestinal inflammation on the bacterial proteome was studied. Within 8 weeks, IL-10(-/-) mice monoassociated with E. coli UNC exhibited an increased expression of several proinflammatory markers in caecal mucosa. Escherichia coli Nissle-associated IL-10(-/-) mice did not do so. As observed previously for E. coli from mice with acute colitis, glycolytic enzymes were downregulated in intestinal E. coli UNC from IL-10(-/-) mice. In addition, the inhibitor of vertebrate C-type lysozyme, Ivy, was upregulated on messenger RNA (mRNA) and protein level in E. coli Nissle from IL-10(-/-) mice compared with E. coli UNC from these mice. Higher expression of Ivy in E. coli Nissle correlated with an improved growth of this probiotic strain in the presence of lysozyme-ethylenediaminetetraacetic acid (EDTA). By overexpressing Ivy, we demonstrated that Ivy contributes to a higher lysozyme resistance of E. coli, supporting the role of Ivy as a potential fitness factor. However, deletion of Ivy did not alter the growth phenotype of E. coli Nissle in the presence of lysozyme-EDTA, suggesting the existence of additional lysozyme inhibitors that can take over the function of Ivy. PMID:23855897

  5. Kinetics of Schiff base on Escherichia coli by microcalorimetry

    Institute of Scientific and Technical Information of China (English)

    许名飞; 李新海; 万洪文; 刘义

    2003-01-01

    The influence of four kinds of Schiff bases on a strain of Escherichia coli was studied by microcalorimetry. Differences in their capabilities of suppressing the metabolism of this bacterium were observed. The results show that the extent and duration of the inhibitory effect on the metabolism as judged from the multiplication rate constant, k, varies with different Schiff bases.The multiplication rate constant k, of Escherichia coli (in log phase) in the presence of Mo-salicylioaldehyde-thiadizole, Mo-piperonaldehyde-thiosemicarbazone and Mo-3-methoxy-salicylicaldehyde-thiadizole decreases with the increase of concentrations of compounds c, and the relationships between k and c, maximum heat production rate Pm and c, peak time of growth curves tp and c are of linearity. For Mo-6-nitro-pieronalde-thiosemicarbazone, the multiplication rate constant is constant irrespective of variation in concentration. The sequence of antibiotic activity of Schiff base is: Mo-salicylioaldehyde-thiadizole>Mo-3-methoxy-salicylicaldehyde-thiadizole>Mo-piperonaldehyde-thiosemicarbazone> 6-nitro-pieronalde-thiosemicarbazone.

  6. Growth of the modeling of Escherichia coli in milk

    International Nuclear Information System (INIS)

    Escherichia coli is a contaminant potential of milk. Collective toxinfections implying the bacterium and milk were announced of share the world. However, no identified work proposed a mathematical expression of the growth of the bacterium in milk. The interest of such a step is however undeniable. Under specified conditions, the mathematical formulation of the growth provides the means of considering the population bacterial when the analyses cannot be carried out. It also makes it possible to test the negatiable instruments of the unfavourable circumstances supposed suchas chain breakage of cold on the development of the microbial charge. This work established mathematical expressions of the growth of Escherichia coli in milk for part of its range of temperature of growth suboptimale i.e. between 25 and 35 Deg C. It was not possible to generalize these expressions for predictions on all the range of temperature suboptimal. This work also made it possible to highlight a deviation of the behavoir of the bacterium compared to the model of Ratkowsky without however that it is not possible to provide a univocal explanantion of it. Varoius assumptions were put forth referring to either a singularity of the behavior of the bacterium or a skew of the value of its minimal temperature of growth

  7. New Method for Laboratory Detection of AmpC β-Lactamases in Escherichia coli and Klebsiella pneumoniae

    OpenAIRE

    Nasim, K.; Elsayed, S.; Pitout, J. D. D.; Conly, J.; Church, D. L.; Gregson, D. B.

    2004-01-01

    A new cefoxitin-agar medium (CAM)-based assay was compared to the previously published modified three-dimensional (M3D) assay for the detection of AmpC production in Escherichia coli and Klebsiella pneumoniae. Clinical isolates of cefoxitin-resistant E. coli (n = 5) and K. pneumoniae (n = 7) and multiple control strains with and without AmpC enzymes were tested by both methods. The CAM method with 4 μg of cefoxitin/ml was equivalent to the M3D method for detecting AmpC production in E. coli a...

  8. Genetic determinants of heat resistance in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ryan eMercer

    2015-09-01

    Full Text Available Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR. This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli.

  9. Anaerobic respiration of Escherichia coli in the mouse intestine.

    Science.gov (United States)

    Jones, Shari A; Gibson, Terri; Maltby, Rosalie C; Chowdhury, Fatema Z; Stewart, Valley; Cohen, Paul S; Conway, Tyrrell

    2011-10-01

    The intestine is inhabited by a large microbial community consisting primarily of anaerobes and, to a lesser extent, facultative anaerobes, such as Escherichia coli, which we have shown requires aerobic respiration to compete successfully in the mouse intestine (S. A. Jones et al., Infect. Immun. 75:4891-4899, 2007). If facultative anaerobes efficiently lower oxygen availability in the intestine, then their sustained growth must also depend on anaerobic metabolism. In support of this idea, mutants lacking nitrate reductase or fumarate reductase have extreme colonization defects. Here, we further explore the role of anaerobic respiration in colonization using the streptomycin-treated mouse model. We found that respiratory electron flow is primarily via the naphthoquinones, which pass electrons to cytochrome bd oxidase and the anaerobic terminal reductases. We found that E. coli uses nitrate and fumarate in the intestine, but not nitrite, dimethyl sulfoxide, or trimethylamine N-oxide. Competitive colonizations revealed that cytochrome bd oxidase is more advantageous than nitrate reductase or fumarate reductase. Strains lacking nitrate reductase outcompeted fumarate reductase mutants once the nitrate concentration in cecal mucus reached submillimolar levels, indicating that fumarate is the more important anaerobic electron acceptor in the intestine because nitrate is limiting. Since nitrate is highest in the absence of E. coli, we conclude that E. coli is the only bacterium in the streptomycin-treated mouse large intestine that respires nitrate. Lastly, we demonstrated that a mutant lacking the NarXL regulator (activator of the NarG system), but not a mutant lacking the NarP-NarQ regulator, has a colonization defect, consistent with the advantage provided by NarG. The emerging picture is one in which gene regulation is tuned to balance expression of the terminal reductases that E. coli uses to maximize its competitiveness and achieve the highest possible population in

  10. Evaluation of a Method Using Three Genomic Guided Escherichia coli Markers for Phylogenetic Typing of E. coli Isolates of Various Genetic Backgrounds.

    Science.gov (United States)

    Hamamoto, Kouta; Ueda, Shuhei; Yamamoto, Yoshimasa; Hirai, Itaru

    2015-06-01

    Genotyping and characterization of bacterial isolates are essential steps in the identification and control of antibiotic-resistant bacterial infections. Recently, one novel genotyping method using three genomic guided Escherichia coli markers (GIG-EM), dinG, tonB, and dipeptide permease (DPP), was reported. Because GIG-EM has not been fully evaluated using clinical isolates, we assessed this typing method with 72 E. coli collection of reference (ECOR) environmental E. coli reference strains and 63 E. coli isolates of various genetic backgrounds. In this study, we designated 768 bp of dinG, 745 bp of tonB, and 655 bp of DPP target sequences for use in the typing method. Concatenations of the processed marker sequences were used to draw GIG-EM phylogenetic trees. E. coli isolates with identical sequence types as identified by the conventional multilocus sequence typing (MLST) method were localized to the same branch of the GIG-EM phylogenetic tree. Sixteen clinical E. coli isolates were utilized as test isolates without prior characterization by conventional MLST and phylogenetic grouping before GIG-EM typing. Of these, 14 clinical isolates were assigned to a branch including only isolates of a pandemic clone, E. coli B2-ST131-O25b, and these results were confirmed by conventional typing methods. Our results suggested that the GIG-EM typing method and its application to phylogenetic trees might be useful tools for the molecular characterization and determination of the genetic relationships among E. coli isolates. PMID:25809972

  11. Wastewater as a Source of Carbapenem Resistant Escherichia coli

    Science.gov (United States)

    Clinical studies have reported that the occurrence of carbapenem resistant E. coli is on the rise. This is of concern because carbapenem antibiotics are typically reserved for treating infections caused by bacteria resistant to other classes of antibiotics. Current literature st...

  12. Immobilizing live Escherichia coli for AFM studies of surface dynamics

    International Nuclear Information System (INIS)

    Atomic force microscopy (AFM) is a probe-based technique that permits high resolution imaging of live bacterial cells. However, stably immobilizing cells to withstand the probe-based lateral forces remains an obstacle in AFM mediated studies, especially those of live, rod shaped bacteria in nutrient media. Consequently, AFM has been under-utilized in the research of bacterial surface dynamics. The aim of the current study was to immobilize a less adherent Escherichia coli strain in a method that both facilitates AFM imaging in nutrient broth and preserves overall cell viability. Immobilization reagents and buffers were systematically evaluated and the cell membrane integrity was monitored in all sample preparations. As expected, the biocompatible gelatin coated surfaces facilitated stable cell attachment in lower ionic strength buffers, yet poorly immobilized cells in higher ionic strength buffers. In comparison, poly-L-lysine surfaces bound cells in both low and high ionic strength buffers. The benefit of the poly-L-lysine binding capacity was offset by the compromised membrane integrity exhibited by cells on poly-L-lysine surfaces. However, the addition of divalent cations and glucose to the immobilization buffer was found to mitigate this unfavorable effect. Ultimately, immobilization of E. coli cells on poly-L-lysine surfaces in a lower ionic strength buffer supplemented with Mg2+ and Ca2+ was determined to provide optimal cell attachment without compromising the overall cell viability. Cells immobilized in this method were stably imaged in media through multiple division cycles. Furthermore, permeability assays indicated that E. coli cells recover from the hypoosmotic stress caused by immobilization in low ionic strength buffers. Taken together, this data suggests that stable immobilization of viable cells on poly-L-lysine surfaces can be accomplished in lower ionic strength buffers that are supplemented with divalent cations for membrane stabilization while

  13. Immobilizing live Escherichia coli for AFM studies of surface dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Lonergan, N.E.; Britt, L.D.; Sullivan, C.J., E-mail: sullivcj@evms.edu

    2014-02-01

    Atomic force microscopy (AFM) is a probe-based technique that permits high resolution imaging of live bacterial cells. However, stably immobilizing cells to withstand the probe-based lateral forces remains an obstacle in AFM mediated studies, especially those of live, rod shaped bacteria in nutrient media. Consequently, AFM has been under-utilized in the research of bacterial surface dynamics. The aim of the current study was to immobilize a less adherent Escherichia coli strain in a method that both facilitates AFM imaging in nutrient broth and preserves overall cell viability. Immobilization reagents and buffers were systematically evaluated and the cell membrane integrity was monitored in all sample preparations. As expected, the biocompatible gelatin coated surfaces facilitated stable cell attachment in lower ionic strength buffers, yet poorly immobilized cells in higher ionic strength buffers. In comparison, poly-L-lysine surfaces bound cells in both low and high ionic strength buffers. The benefit of the poly-L-lysine binding capacity was offset by the compromised membrane integrity exhibited by cells on poly-L-lysine surfaces. However, the addition of divalent cations and glucose to the immobilization buffer was found to mitigate this unfavorable effect. Ultimately, immobilization of E. coli cells on poly-L-lysine surfaces in a lower ionic strength buffer supplemented with Mg{sup 2+} and Ca{sup 2+} was determined to provide optimal cell attachment without compromising the overall cell viability. Cells immobilized in this method were stably imaged in media through multiple division cycles. Furthermore, permeability assays indicated that E. coli cells recover from the hypoosmotic stress caused by immobilization in low ionic strength buffers. Taken together, this data suggests that stable immobilization of viable cells on poly-L-lysine surfaces can be accomplished in lower ionic strength buffers that are supplemented with divalent cations for membrane

  14. [Improving 3-dehydroshikimate production by metabolically engineered Escherichia coli].

    Science.gov (United States)

    Yuan, Fei; Chen, Wujiu; Jia, Shiru; Wang, Qinhong

    2014-10-01

    In the aromatic amino acid biosynthetic pathway 3-dehydroshikimate (DHS) is a key intermediate. As a potent antioxidant and important feedstock for producing a variety of important industrial chemicals, such as adipate and vanillin, DHS is of great commercial value. Here, in this study, we investigated the effect of the co-expression of aroFFBR (3-deoxy-D-arabino-heptulosonate 7-phosphate synthase mutant with tyrosine feedback-inhibition resistance) and tktA (Transketolase A) at different copy number on the production of DHS. The increased copy number of aroFFBR and tktA would enhance the production of DHS by the fold of 2.93. In order to further improve the production of DHS, we disrupted the key genes in by-product pathways of the parent strain Escherichia coli AB2834. The triple knockout strain of ldhA, ackA-pta and adhE would further increase the production of DHS. The titer of DHS in shake flask reached 1.83 g/L, 5.7-fold higher than that of the parent strain E. coli AB2834. In 5-L fed-batch fermentation, the metabolically engineered strain produced 25.48 g/L DHS after 62 h. Metabolically engineered E. coli has the potential to further improve the production of DHS. PMID:25726580

  15. Recombinant expression of Streptococcus pneumoniae capsular polysaccharides in Escherichia coli

    Science.gov (United States)

    Kay, Emily J.; Yates, Laura E.; Terra, Vanessa S.; Cuccui, Jon; Wren, Brendan W.

    2016-01-01

    Currently, Streptococcus pneumoniae is responsible for over 14 million cases of pneumonia worldwide annually, and over 1 million deaths, the majority of them children. The major determinant for pathogenesis is a polysaccharide capsule that is variable and is used to distinguish strains based on their serotype. The capsule forms the basis of the pneumococcal polysaccharide vaccine (PPV23) that contains purified capsular polysaccharide from 23 serotypes, and the pneumococcal conjugate vaccine (PCV13), containing 13 common serotypes conjugated to CRM197 (mutant diphtheria toxin). Purified capsule from S. pneumoniae is required for pneumococcal conjugate vaccine production, and costs can be prohibitively high, limiting accessibility of the vaccine in low-income countries. In this study, we demonstrate the recombinant expression of the capsule-encoding locus from four different serotypes of S. pneumoniae within Escherichia coli. Furthermore, we attempt to identify the minimum set of genes necessary to reliably and efficiently express these capsules heterologously. These E. coli strains could be used to produce a supply of S. pneumoniae serotype-specific capsules without the need to culture pathogenic bacteria. Additionally, these strains could be applied to synthetic glycobiological applications: recombinant vaccine production using E. coli outer membrane vesicles or coupling to proteins using protein glycan coupling technology. PMID:27110302

  16. Fecal leukocytes in children infected with diarrheagenic Escherichia coli.

    Science.gov (United States)

    Mercado, Erik H; Ochoa, Theresa J; Ecker, Lucie; Cabello, Martin; Durand, David; Barletta, Francesca; Molina, Margarita; Gil, Ana I; Huicho, Luis; Lanata, Claudio F; Cleary, Thomas G

    2011-04-01

    The purpose of this study was to determine the presence and quantity of fecal leukocytes in children infected with diarrheagenic Escherichia coli and to compare these levels between diarrhea and control cases. We analyzed 1,474 stool samples from 935 diarrhea episodes and 539 from healthy controls of a cohort study of children younger than 2 years of age in Lima, Peru. Stools were analyzed for common enteric pathogens, and diarrheagenic E. coli isolates were studied by a multiplex real-time PCR. Stool smears were stained with methylene blue and read by a blinded observer to determine the number of polymorphonuclear leukocytes per high-power field (L/hpf). Fecal leukocytes at >10 L/hpf were present in 11.8% (110/935) of all diarrheal episodes versus 1.1% (6/539) in controls (P 10 L/hpf were present in 8.5% (18/212) of diarrhea versus 1.3% (2/157) of control samples (P 10 L/hpf) with an odds ratio (OR) of 4.1 (95% confidence interval [CI], 1.08 to 15.51; P < 0.05). Although diarrheagenic E. coli was isolated with similar frequencies in diarrhea and control samples, clearly it was associated with a more inflammatory response during symptomatic infection; however, in general, these pathogens elicited a mild inflammatory response. PMID:21325554

  17. Genomic islands of uropathogenic Escherichia coli contribute to virulence.

    Science.gov (United States)

    Lloyd, Amanda L; Henderson, Tiffany A; Vigil, Patrick D; Mobley, Harry L T

    2009-06-01

    Uropathogenic Escherichia coli (UPEC) strain CFT073 contains 13 large genomic islands ranging in size from 32 kb to 123 kb. Eleven of these genomic islands were individually deleted from the genome, and nine isogenic mutants were tested for their ability to colonize the CBA/J mouse model of ascending urinary tract infection. Three genomic island mutants (Delta PAI-aspV, Delta PAI-metV, and Delta PAI-asnT) were significantly outcompeted by wild-type CFT073 in the bladders and/or kidneys following transurethral cochallenge (P Delta c2518-15) was significantly outcompeted by wild-type CFT073 in cochallenge. Strains with mutations in a type VI secretion system within the PAI-metV island did not show attenuation. The attenuation of the PAI-metV island was localized to genes c3405-10, encoding a putative phosphotransferase transport system, which is common to UPEC and avian pathogenic E. coli strains but absent from E. coli K-12. We have shown that, in addition to encoding virulence genes, genomic islands contribute to the overall fitness of UPEC strain CFT073 in vivo. PMID:19329634

  18. Identification of Diarrheagenic Escherichia coli Strains from Avian Organic Fertilizers

    Directory of Open Access Journals (Sweden)

    Juan Puño-Sarmiento

    2014-08-01

    Full Text Available The Brazilian poultry industry generates large amounts of organic waste, such as chicken litter, which is often used in agriculture. Among the bacteria present in organic fertilizer are members of the Enterobacteriaceae family. The objective of this study was to detect the presence of diarrheagenic Escherichia coli (DEC strains in avian organic fertilizer, and assess the potential damage they can cause in humans due to antimicrobial resistance. The presence of DEC pathotypes and phylogenetic groups were detected by multiplex-PCR. Phenotypic assays, such as tests for adhesion, cytotoxicity activity, biofilm formation and especially antimicrobial susceptibility, were performed. Fifteen DEC strains from 64 E. coli were isolated. Among these, four strains were classified as enteropathogenic (EPEC; 6.2%, three strains as Shiga toxin-producing (STEC; 4.7%, 10 strains as enteroaggregative (EAEC; 12.5%, but two of these harbored the eaeA gene too. The low number of isolated strains was most likely due to the composting process, which reduces the number of microorganisms. These strains were able to adhere to HEp-2 and HeLa cells and produce Shiga-toxins and biofilms; in addition, some of the strains showed antimicrobial resistance, which indicates a risk of the transfer of resistance genes to human E. coli. These results showed that DEC strains isolated from avian organic fertilizers can cause human infections.

  19. Starved Escherichia coli preserve reducing power under nitric oxide stress.

    Science.gov (United States)

    Gowers, Glen-Oliver F; Robinson, Jonathan L; Brynildsen, Mark P

    2016-07-15

    Nitric oxide (NO) detoxification enzymes, such as NO dioxygenase (NOD) and NO reductase (NOR), are important to the virulence of numerous bacteria. Pathogens use these defense systems to ward off immune-generated NO, and they do so in environments that contain additional stressors, such as reactive oxygen species, nutrient deprivation, and acid stress. NOD and NOR both use reducing equivalents to metabolically deactivate NO, which suggests that nutrient deprivation could negatively impact their functionality. To explore the relationship between NO detoxification and nutrient deprivation, we examined the ability of Escherichia coli to detoxify NO under different levels of carbon source availability in aerobic cultures. We observed failure of NO detoxification under both carbon source limitation and starvation, and those failures could have arisen from inabilities to synthesize Hmp (NOD of E. coli) and/or supply it with sufficient NADH (preferred electron donor). We found that when limited quantities of carbon source were provided, NO detoxification failed due to insufficient NADH, whereas starvation prevented Hmp synthesis, which enabled cells to maintain their NADH levels. This maintenance of NADH levels under starvation was confirmed to be dependent on the absence of Hmp. Intriguingly, these data show that under NO stress, carbon-starved E. coli are better positioned with regard to reducing power to cope with other stresses than cells that had consumed an exhaustible amount of carbon. PMID:27207837

  20. 2DBase: 2D-PAGE database of Escherichia coli.

    Science.gov (United States)

    Vijayendran, Chandran; Burgemeister, Sebastian; Friehs, Karl; Niehaus, Karsten; Flaschel, Erwin

    2007-11-23

    We present a web-based integrated proteome database, termed 2DBase of Escherichia coli which was designed to store, compare, analyse, and retrieve various information obtained by 2D polyacrylamide gel electrophoresis and mass spectrometry. The main objectives of this database are (1) to provide the features for query and data-mining applications to access the stored proteomics data (2) to efficiently compare the specific protein spots present in the comparable proteome maps and (3) to analyse the data with the integrated classification for cellular functions of gene products of E. coli. This database currently contains 12 gels consisting of 1185 protein spots information in which 723 proteins were identified and annotated. Individual protein spots in the existing gels can be displayed, queried, analyzed, and compared in a tabular format based on various functional categories enabling quick and subsequent analyses. Our database satisfies the requirement to be a federated 2-DE database by accomplishing various tasks through a web interface providing access to a relational database system. The 2DBase of E. coli database can be accessed at http://2dbase.techfak.uni-bielefeld.de/. PMID:17904107

  1. Escherichia coli bacteria detection by using graphene-based biosensor.

    Science.gov (United States)

    Akbari, Elnaz; Buntat, Zolkafle; Afroozeh, Abdolkarim; Zeinalinezhad, Alireza; Nikoukar, Ali

    2015-10-01

    Graphene is an allotrope of carbon with two-dimensional (2D) monolayer honeycombs. A larger detection area and higher sensitivity can be provided by graphene-based nanosenor because of its 2D structure. In addition, owing to its special characteristics, including electrical, optical and physical properties, graphene is known as a more suitable candidate compared to other materials used in the sensor application. A novel model employing a field-effect transistor structure using graphene is proposed and the current-voltage (I-V) characteristics of graphene are employed to model the sensing mechanism. This biosensor can detect Escherichia coli (E. coli) bacteria, providing high levels of sensitivity. It is observed that the graphene device experiences a drastic increase in conductance when exposed to E. coli bacteria at 0-10(5) cfu/ml concentration. The simple, fast response and high sensitivity of this nanoelectronic biosensor make it a suitable device in screening and functional studies of antibacterial drugs and an ideal high-throughput platform which can detect any pathogenic bacteria. Artificial neural network and support vector regression algorithms have also been used to provide other models for the I-V characteristic. A satisfactory agreement has been presented by comparison between the proposed models with the experimental data. PMID:26435280

  2. Metabolic engineering of Escherichia coli to produce zeaxanthin.

    Science.gov (United States)

    Li, Xi-Ran; Tian, Gui-Qiao; Shen, Hong-Jie; Liu, Jian-Zhong

    2015-04-01

    Zeaxanthin is a high-value carotenoid that is used in nutraceuticals, cosmetics, food, and animal feed industries. Zeaxanthin is chemically synthesized or purified from microorganisms as a natural product; however, increasing demand requires development of alternative sources such as heterologous biosynthesis by recombinant bacteria. For this purpose, we molecularly engineered Escherichia coli to optimize the synthesis of zeaxanthin from lycopene using fusion protein-mediated substrate channeling as well as by the introduction of tunable intergenic regions. The tunable intergenic regions approach was more efficient compared with protein fusion for coordinating expression of lycopene β-cyclase gene crtY and β-carotene 3-hydroxylase gene crtZ. The influence of the substrate channeling effect suggests that the reaction catalyzed by CrtZ is the rate-limiting step in zeaxanthin biosynthesis. Then Pantoea ananatis, Pantoea agglomerans and Haematococcus pluvialis crtZ were compared. Because P. ananatis crtZ is superior to that of P. agglomerans or H. pluvialis for zeaxanthin production, we used it to generate a recombinant strain of E. coli BETA-1 containing pZSPBA-2(P37-crtZPAN) that produced higher amounts of zeaxanthin (11.95 ± 0.21 mg/g dry cell weight) than other engineered E. coli strains described in the literature. PMID:25533633

  3. Properties of a Clostridium thermocellum Endoglucanase Produced in Escherichia coli.

    Science.gov (United States)

    Schwarz, W H; Gräbnitz, F; Staudenbauer, W L

    1986-06-01

    A cellulase gene of Clostridium thermocellum was transferred to Escherichia coli by molecular cloning with bacteriophage lambda and plasmid vectors and shown to be indentical with the celA gene. The celA gene product was purified from extracts of plasmid-bearing E. coli cells by heat treatment and chromatography on DEAE-Trisacryl. It was characterized as a thermophilic endo-beta-1,4-glucanase, the properties of which closely resemble those of endoglucanase A previously isolated from C. thermocellum supernatants. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis the enzyme purified from E. coli exhibited two protein bands with molecular weights of 49,000 and 52,000. It had a temperature optimum at 75 degrees C and was stable for several hours at 60 degrees C. Endoglucanase activity was optimal between pH 5.5 and 6.5. The enzyme was insensitive against end product inhibition by glucose and cellobiose and remarkably resistant to the denaturing effects of detergents and organic solvents. It was capable of degrading, in addition to cellulosic substrates, glucans with alternating beta-1,4 and beta-1,3 linkages such as barley beta-glucan and lichenan. PMID:16347088

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

    OpenAIRE

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

    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....

  5. Plasmid profiling of multidrug resistant Escherichia coli strains isolated from urinary tract infection patients

    OpenAIRE

    Sabin Khadgi; Uddhav Timilsina; Basudha Shrestha

    2013-01-01

    Introduction- Urinary tract infection is a common community-acquired bacterial disease. Escherichia coli is reported to be the major cause of urinary tract infection. Aim & Objective- The study was conducted with the aim of determining the antibiotic resistance pattern and plasmid profile of multidrug resistant Escherichia coli isolated from Urinary Tract Infection patients. Materials and Method- Antibiotic susceptibility tests were performed against E. coli following the protocol for the Kir...

  6. Evaluating Antimicrobial Effects of Centaurea Plant’s Essential Oil on Pathogenic Bacteria: Staphylococcus Aureus, Staphylococcus Epidermidis, and Escherichia Coli Isolated from Clinical Specimens

    OpenAIRE

    Haedeh Mobaiyen; Abolfazl Jafari Sales; Javad Sayyahi

    2016-01-01

    Background & Objectives :Nowadays, development of drug resistance against chemical antimicrobial drugs has attracted attention using medicinal plants in treatment of infections. The aim of this study is to evaluate the antimicrobial effects of two species of Centaurea plant’s essential oil on drug resistant clinical isolates of three pathogenic isolates. Materials & Methods :The studied plants were collected from Marand city in East Azerbaijan, Iran and were confirmed ...

  7. Contribution of Escherichia coli alpha-hemolysin to bacterial virulence and to intraperitoneal alterations in peritonitis.

    Science.gov (United States)

    May, A K; Gleason, T G; Sawyer, R G; Pruett, T L

    2000-01-01

    Alpha-hemolysin (Hly) is a common exotoxin produced by Escherichia coli that enhances virulence in a number of clinical infections. The addition of hemolysin production to laboratory bacterial strains is known to increase the lethality of E. coli peritonitis. However, the mechanisms involved have not been determined and the contribution of hemolysin to the alterations in the host intraperitoneal environment and the leukocyte response is not known. Utilizing a rat peritonitis model, we show that wild-type hemolytic E. coli strains have a significant competitive advantage over nonhemolytic strains within the peritoneum. To examine the specific contribution of Hly to E. coli-induced virulence and alterations within the peritoneum, a mixed peritonitis model of E. coli, Bacteroides fragilis, and sterile fecal adjuvant was used. Three transformed E. coli strains were utilized: one strongly secretes active hemolysin (WAF 270), a second secretes active hemolysin but a reduced amount (WAF 260), and the third does not produce hemolysin (WAF 108). After an equal inoculum of each of the three strains, WAF 270 produced a markedly increased lethality and an increased recovery of both E. coli and B. fragilis from the host relative to the other strains. Changes in the intraperitoneal pH, degree of erythrocyte lysis, and recruitment and viability of leukocytes within the peritoneum following the induction of peritonitis differed significantly between the strongly hemolytic and nonhemolytic strains. Induction of peritonitis with WAF 270 caused a pronounced decrease in intraperitoneal pH, lysis of most of the intraperitoneal erythrocytes, and a marked decrease in recoverable viable leukocytes compared to WAF 108. Thus, hemolysin production by E. coli within the peritoneum may alter not only the host's ability to control the hemolytic strain itself but also other organisms. PMID:10603385

  8. Long-term dissemination of acquired AmpC β-lactamases among Klebsiella spp. and Escherichia coli in Portuguese clinical settings

    OpenAIRE

    Freitas, Francisco; Machado, Elisabete; Ribeiro, Teresa; Novais, Ângela; Peixe, Luísa

    2014-01-01

    We investigated the occurrence, diversity and molecular epidemiology of genes coding for acquired AmpC β-lactamases (qAmpC) among clinical isolates of Enterobacteriaceae lacking inducible chromosomal AmpCs in Portugal. A total of 675 isolates non-susceptible to broad-spectrum cephalosporins obtained from four hospitals and three community laboratories during a 7-year period (2002-2008) were analysed. The presence of genes coding for qAmpC was investigated by phenotypic criteria, polymerase ch...

  9. Association of Escherichia coli J5-Specific Serum Antibody Responses with Clinical Mastitis Outcome for J5 Vaccinate and Control Dairy Cattle ▿

    OpenAIRE

    Wilson, David J.; Mallard, Bonnie A.; Burton, Jeanne L.; Schukken, Ynte H.; Grohn, Yrjo T

    2008-01-01

    Dairy cattle in two commercial Holstein herds were randomly selected to be vaccinated twice with J5, at approximately 60 days and 28 days before the expected calving date, or to be untreated controls. Based on whether milk production changed following clinical mastitis or whether cows were culled or died within 30 days after onset, 51 mastitis cases were classified as severe or mild. J5-specific antibody responses were evaluated by enzyme-linked immunosorbent assay of all 32 severe and 19 mil...

  10. Genetic Features of MCR-1-Producing Colistin-Resistant Escherichia coli Isolates in South Africa.

    Science.gov (United States)

    Poirel, Laurent; Kieffer, Nicolas; Brink, Adrian; Coetze, Jennifer; Jayol, Aurélie; Nordmann, Patrice

    2016-07-01

    A series of colistin-resistant Escherichia coli clinical isolates was recovered from hospitalized and community patients in South Africa. Seven clonally unrelated isolates harbored the mcr-1 gene located on different plasmid backbones. Two distinct plasmids were fully sequenced, and identical 2,600-bp-long DNA sequences defining a mcr-1 cassette were identified. Promoter sequences responsible for the expression of mcr-1, deduced from the precise identification of the +1 transcription start site for mcr-1, were characterized. PMID:27161623

  11. Multilaboratory Validation of Rapid Spot Tests for Identification of Escherichia coli

    OpenAIRE

    York, Mary K.; Baron, Ellen Jo; Clarridge, Jill E.; Thomson, Richard B.; Weinstein, Melvin P.

    2000-01-01

    To validate the accuracy of rapid tests for identification of Escherichia coli, five laboratories sequentially collected 1,064 fresh, clinically significant strains with core criteria of indole-positive, oxidase-negative, nonspreading organisms on sheep blood agar plates (BAP), having typical gram-negative rod plate morphology, defined as good growth on gram-negative rod-selective media. An algorithm using beta-hemolysis on BAP, lactose reaction on eosin-methylene blue or MacConkey agar, l-py...

  12. 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…

  13. 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...

  14. Diet, fecal microbiome and Escherichia coli O157:H7 shedding in beef Cattle

    Science.gov (United States)

    Shiga-toxigenic Escherichia coli, such as E. coli O157:H7, are foodborne zoonotic pathogens that can cause severe illness and death in humans. The gastrointestinal tract of ruminant animals has been identified as a primary habitat for E. coli O157:H7, and in cattle the terminal gastrointestinal tra...

  15. Colonization with Extraintestinal Pathogenic Escherichia coli among Nursing Home Residents and Its Relationship to Fluoroquinolone Resistance

    OpenAIRE

    Maslow, Joel N.; Lautenbach, Ebbing; Glaze, Thomas; Bilker, Warren; Johnson, James R.

    2004-01-01

    In a cross-sectional fecal prevalence survey involving 49 residents of a Veterans Affairs nursing home, 59% of subjects were colonized with extraintestinal pathogenic Escherichia coli (ExPEC), 22% were colonized with adhesin-positive E. coli, and 51% were colonized with fluoroquinolone-resistant E. coli. Among 80 unique isolates, adhesins correlated negatively and aerobactin correlated positively with fluoroquinolone resistance.

  16. Dietary interactions and interventions affecting Escherichia coli 0157 colonization and shedding in cattle

    Science.gov (United States)

    Escherichia coli O157 is an important foodborne pathogen affecting human health and the beef cattle industry. Contamination of carcasses at slaughter is correlated to the prevalence of E. coli O157 in cattle feces. Many associations have been made between dietary factors and E. coli O157 prevalenc...

  17. Escherichia coli O157:H7, diet, and fecal microbiome in beef cattle

    Science.gov (United States)

    Shiga-toxigenic Escherichia coli, such as E. coli O157:H7, are foodborne zoonotic pathogens that can cause severe illness and death in humans. The gastrointestinal tract of ruminant animals has been identified as a primary habitat for E. coli O157:H7, and in cattle the terminal gastrointestinal tra...

  18. Biosynthesis of two quercetin O-diglycosides in Escherichia coli.

    Science.gov (United States)

    An, Dae Gyun; Yang, So Mi; Kim, Bong Gyu; Ahn, Joong-Hoon

    2016-06-01

    Various flavonoid glycosides are found in nature, and their biological activities are as variable as their number. In some cases, the sugar moiety attached to the flavonoid modulates its biological activities. Flavonoid glycones are not easily synthesized chemically. Therefore, in this study, we attempted to synthesize quercetin 3-O-glucosyl (1→2) xyloside and quercetin 3-O-glucosyl (1→6) rhamnoside (also called rutin) using two uridine diphosphate-dependent glycosyltransferases (UGTs) in Escherichia coli. To synthesize quercetin 3-O-glucosyl (1→2) xyloside, sequential glycosylation was carried out by regulating the expression time of the two UGTs. AtUGT78D2 was subcloned into a vector controlled by a Tac promoter without a lacI operator, while AtUGT79B1 was subcloned into a vector controlled by a T7 promoter. UDP-xyloside was supplied by concomitantly expressing UDP-glucose dehydrogenase (ugd) and UDP-xyloside synthase (UXS) in the E. coli. Using these strategies, 65.0 mg/L of quercetin 3-O-glucosyl (1→2) xyloside was produced. For the synthesis of rutin, one UGT (BcGT1) was integrated into the E. coli chromosome and the other UGT (Fg2) was expressed in a plasmid along with RHM2 (rhamnose synthase gene 2). After optimization of the initial cell concentration and incubation temperature, 119.8 mg/L of rutin was produced. The strategies used in this study thus show promise for the synthesis of flavonoid diglucosides in E. coli. PMID:26931782

  19. First Report of Klebsiella pneumoniae-Carbapenemase-3-Producing Escherichia coli ST479 in Poland

    Directory of Open Access Journals (Sweden)

    Dominika Ojdana

    2015-01-01

    Full Text Available An increase in the antibiotic resistance among members of the Enterobacteriaceae family has been observed worldwide. Multidrug-resistant Gram-negative rods are increasingly reported. The treatment of infections caused by Escherichia coli and other Enterobacteriaceae has become an important clinical problem associated with reduced therapeutic possibilities. Antimicrobial carbapenems are considered the last line of defense against multidrug-resistant Gram-negative bacteria. Unfortunately, an increase of carbapenem resistance due to the production of Klebsiella pneumoniae carbapenemase (KPC enzymes has been observed. In this study we describe the ability of E. coli to produce carbapenemase enzymes based on the results of the combination disc assay with boronic acid performed according to guidelines established by the European Community on Antimicrobial Susceptibility Testing (EUCAST and the biochemical Carba NP test. Moreover, we evaluated the presence of genes responsible for the production of carbapenemases (blaKPC, blaVIM, blaIMP, blaOXA-48 and genes encoding other β-lactamases (blaSHV, blaTEM, blaCTX-M among E. coli isolate. The tested isolate of E. coli that possessed the blaKPC-3 and blaTEM-34 genes was identified. The tested strain exhibited susceptibility to colistin (0.38 μg/mL and tigecycline (1 μg/mL. This is the first detection of blaKPC-3 in an E. coli ST479 in Poland.

  20. Nissui Glucose Fermentative Gram-Negative Rod Identification System EB-20 Gives a Unique Profile for Typical Non-Sorbitol-Fermenting Escherichia coli O157:H7

    OpenAIRE

    Kodaka, H; Uesaka, Y; Kashitani, F

    2004-01-01

    The 98 non-sorbitol-fermenting (NSF) Escherichia coli O157:H7 strains identified on a Nissui glucose fermentative gram-negative rod identification system (EB-20) gave a unique biochemical profile number that was not detected in 85 pathogenic and 13 nonpathogenic E. coli strains. Thus, EB-20 is useful for the identification of NSF E. coli O157:H7 and provides a simple, cost-effective, and reliable tool for clinical laboratories.

  1. Escherichia coli Strains Isolated from the Uteri Horn, Mouth, and Rectum of Bitches Suffering from Pyometra: Virulence Factors, Antimicrobial Susceptibilities, and Clonal Relationships among Strains

    OpenAIRE

    Agostinho, Juliana M. A.; Andressa de Souza; Schocken-Iturrino, Ruben P.; Beraldo, Lívia G.; Borges, Clarissa A.; Fernando A. Ávila; José M. Marin

    2014-01-01

    Pyometra is recognized as one of the main causes of disease and death in the bitch, and Escherichia coli is the major pathogen associated with this disease. In this study, 70 E. coli isolates from the uteri horn, mouth, and rectum of bitches suffering from the disease and 43 E. coli isolates from the rectum of clinically healthy bitches were examined for the presence of uropathogenic virulence genes and susceptibility to antimicrobial drugs. DNA profiles of isolates from uteri horn and mouth ...

  2. Reproducible gene targeting in recalcitrant Escherichia coli isolates

    Directory of Open Access Journals (Sweden)

    De Greve Henri

    2011-06-01

    Full Text Available Abstract Background A number of allele replacement methods can be used to mutate bacterial genes. For instance, the Red recombinase system of phage Lambda has been used very efficiently to inactivate chromosomal genes in E. coli K-12, through recombination between regions of homology. However, this method does not work reproducibly in some clinical E. coli isolates. Findings The procedure was modified by using longer homologous regions (85 bp and 500-600 bp, to inactivate genes in the uropathogenic E. coli strain UTI89. An lrhA regulator mutant, and deletions of the lac operon as well as the complete type 1 fimbrial gene cluster, were obtained reproducibly. The modified method is also functional in other recalcitrant E. coli, like the avian pathogenic E. coli strain APEC1. The lrhA regulator and lac operon deletion mutants of APEC1 were successfully constructed in the same way as the UTI89 mutants. In other avian pathogenic E. coli strains (APEC3E, APEC11A and APEC16A it was very difficult or impossible to construct these mutants, with the original Red recombinase-based method, with a Red recombinase-based method using longer (85 bp homologous regions or with our modified protocol, using 500 - 600 bp homologous regions. Conclusions The method using 500-600 bp homologous regions can be used reliably in some clinical isolates, to delete single genes or entire operons by homologous recombination. However, it does not invariably show a greater efficiency in obtaining mutants, when compared to the original Red-mediated gene targeting method or to the gene targeting method with 85 bp homologous regions. Therefore the length of the homology regions is not the only limiting factor for the construction of mutants in these recalcitrant strains.

  3. Diversity of Escherichia coli Strains Producing Extended-Spectrum B-Lactamases in Spain: Second Nationwide Study

    OpenAIRE

    Miguel A Díaz; Hernández-Bello, José R.; Rodríguez-Baño, Jesús; Martínez-Martínez, Luis; Calvo, Jorge; Blanco, Jorge; Pascual, Álvaro

    2010-01-01

    The prevalence of extended-spectrum -lactamase (ESBL)-producing Escherichia coli (ESBLEC) in Spain increased 8-fold from 2000 to 2006. ESBL type, clonal relationship, antimicrobial susceptibility, and clinical data about infections caused by ESBLEC are evaluated in a second nationwide study developed in 2006. From 1008 clinical isolates obtained over 2 months from 44 hospitals, 254 were used for further analysis. ESBL production was evaluated by synergy testing, PCR, and sequenci...

  4. Diversity of Escherichia coli Strains Producing Extended-Spectrum β-Lactamases in Spain: Second Nationwide Study ▿

    OpenAIRE

    Miguel A Díaz; Hernández-Bello, José R.; Rodríguez-Baño, Jesús; Martínez-Martínez, Luis; Calvo, Jorge; Blanco, Jorge; Pascual, Alvaro

    2010-01-01

    The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBLEC) in Spain increased 8-fold from 2000 to 2006. ESBL type, clonal relationship, antimicrobial susceptibility, and clinical data about infections caused by ESBLEC are evaluated in a second nationwide study developed in 2006. From 1008 clinical isolates obtained over 2 months from 44 hospitals, 254 were used for further analysis. ESBL production was evaluated by synergy testing, PCR, and sequencing. Antimicr...

  5. Isobutyraldehyde production from Escherichia coli by removing aldehyde reductase activity

    Directory of Open Access Journals (Sweden)

    Rodriguez Gabriel M

    2012-06-01

    Full Text Available Abstract Background Increasing global demand and reliance on petroleum-derived chemicals will necessitate alternative sources for chemical feedstocks. Currently, 99% of chemical feedstocks are derived from petroleum and natural gas. Renewable methods for producing important chemical feedstocks largely remain unaddressed. Synthetic biology enables the renewable production of various chemicals from microorganisms by constructing unique metabolic pathways. Here, we engineer Escherichia coli for the production of isobutyraldehyde, which can be readily converted to various hydrocarbons currently derived from petroleum such as isobutyric acid, acetal, oxime and imine using existing chemical catalysis. Isobutyraldehyde can be readily stripped from cultures during production, which reduces toxic effects of isobutyraldehyde. Results We adopted the isobutanol pathway previously constructed in E. coli, neglecting the last step in the pathway where isobutyraldehyde is converted to isobutanol. However, this strain still overwhelmingly produced isobutanol (1.5 g/L/OD600 (isobutanol vs 0.14 g/L/OD600 (isobutyraldehyde. Next, we deleted yqhD which encodes a broad-substrate range aldehyde reductase known to be active toward isobutyraldehyde. This strain produced isobutanol and isobutyraldehyde at a near 1:1 ratio, indicating further native isobutyraldehyde reductase (IBR activity in E. coli. To further eliminate isobutanol formation, we set out to identify and remove the remaining IBRs from the E. coli genome. We identified 7 annotated genes coding for IBRs that could be active toward isobutyraldehyde: adhP, eutG, yiaY, yjgB, betA, fucO, eutE. Individual deletions of the genes yielded only marginal improvements. Therefore, we sequentially deleted all seven of the genes and assessed production. The combined deletions greatly increased isobutyraldehyde production (1.5 g/L/OD600 and decreased isobutanol production (0.4 g/L/OD600. By assessing production by

  6. Adherent-Invasive Escherichia coli Phenotype Displayed by Intestinal Pathogenic E. coli Strains from Cats, Dogs, and Swine ▿

    OpenAIRE

    Martinez-Medina, Margarita; Garcia-Gil, Jesus; Barnich, Nicolas; Lothar H Wieler; Ewers, Christa

    2011-01-01

    The adherent-invasive Escherichia coli (AIEC) pathotype, which has been associated with Crohn's disease, shows similar traits to human and animal extraintestinal pathogenic E. coli (ExPEC) with respect to their phylogenetic origin and virulence gene profiles. Here, we demonstrate that animal ExPEC strains generally do not share the AIEC phenotype. In contrast, this phenotype is very frequent among animal intestinal pathogenic E. coli (InPEC) strains, particularly of feline and canine origin, ...

  7. Collective motion in an active suspension of Escherichia coli bacteria

    International Nuclear Information System (INIS)

    We investigate experimentally the emergence of collective motion in the bulk of an active suspension of Escherichia coli bacteria. When increasing the concentration from a dilute to a semi-dilute regime, we observe a continuous crossover from a dynamical cluster regime to a regime of ‘bio-turbulence’ convection patterns. We measure a length scale characterizing the collective motion as a function of the bacteria concentration. For bacteria fully supplied with oxygen, the increase of the correlation length is almost linear with concentration and at the largest concentrations tested, the correlation length could be as large as 24 bacterial body sizes (or 7–8 when including the flagella bundle). In contrast, under conditions of oxygen shortage the correlation length saturates at a value of around 7 body lengths. (paper)

  8. Structure of the Cyclomodulin Cif from Pathogenic Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Y.; Jubelin, G; Taieb, F; Nougayrède, J; Oswald, E; Stebbins, C

    2008-01-01

    Bacterial pathogens have evolved a sophisticated arsenal of virulence factors to modulate host cell biology. Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC) use a type III protein secretion system (T3SS) to inject microbial proteins into host cells. The T3SS effector cycle inhibiting factor (Cif) produced by EPEC and EHEC is able to block host eukaryotic cell-cycle progression. We present here a crystal structure of Cif, revealing it to be a divergent member of the superfamily of enzymes including cysteine proteases and acetyltransferases that share a common catalytic triad. Mutation of these conserved active site residues abolishes the ability of Cif to block cell-cycle progression. Finally, we demonstrate that irreversible cysteine protease inhibitors do not abolish the Cif cytopathic effect, suggesting that another enzymatic activity may underlie the biological activity of this virulence factor.

  9. Selection of quiescent Escherichia coli with high metabolic activity.

    Science.gov (United States)

    Sonderegger, Marco; Schümperli, Michael; Sauer, Uwe

    2005-01-01

    Sustained metabolic activity in non-growing, quiescent cells can increase the operational life-span of bio-processes and improve process economics by decoupling production from cell growth. Because of the ill-defined molecular nature of this phenotype, we developed selection protocols for the evolution of quiescent Escherichia coli mutants that exhibit high metabolic activity in ammonium starvation-induced stationary phase. The best enrichment procedures were continuously or discontinuously fed ammonium-limited chemostat cultures with a very low dilution rate of 0.03 h(-1). After 40 generations of selection, improved mutants with up to doubled catabolic rates in stationary phase were isolated. The metabolically most active clones were identified by screening for high specific glucose uptake rates during ammonium starvation-induced stationary phase in deep-well microtiter plates. PMID:15721805

  10. Overexpression of Soluble Human Thymosin Alpha 1 in Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    Pei-Fu CHEN; Hong-Ying ZHANG; Geng-Feng FU; Gen-Xing XU; Ya-Yi HOU

    2005-01-01

    Synthesized gene of human thymosin alpha 1 (Tα1) was inserted into pET-28a, pET-9c,pThioHis B, pGEX-2T or pBV222 and then inductively expressed in strains of Escherichia coli. Among the five expression systems, the BL21/pET-28a system provides the highest expression level of fusion protein in a soluble form, which is up to 70% of total expressed bacterial proteins as visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The resulting fusion protein purified through nickel affinity chromatography accounts for 2.53% of the wet bacterial pellet weight and reaches 94.5% purity by SDS-PAGE. These results indicate the potential of this expression system for high-throughput production of recombinant Tα1.

  11. Theoretical Prediction of Disrupted Min Oscillation in Flattened Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Jeff B Schulte

    Full Text Available The dynamics of the Min-protein system help Escherichia coli regulate the process of cell division by identifying the center of the cell. While this system exhibits robust bipolar oscillations in wild-type cell shapes, recent experiments have shown that when the cells are mechanically deformed into wide, flattened out, irregular shapes, the spatial regularity of these oscillations breaks down. We employ widely used stochastic and deterministic models of the Min system to simulate cells with flattened shapes. The deterministic model predicts strong bipolar oscillations, in contradiction with the experimentally observed behavior, while the stochastic model, which is based on the same reaction-diffusion equations, predicts more spatially irregular oscillations. We further report simulations of flattened but more symmetric shapes, which suggest that the flattening and lateral expansion may contribute as much to the irregular oscillation behavior as the asymmetry of the cell shapes.

  12. A series of template plasmids for Escherichia coli genome engineering.

    Science.gov (United States)

    Deb, Shalini S; Reshamwala, Shamlan M S; Lali, Arvind M

    2016-06-01

    Metabolic engineering strategies often employ multi-copy episomal vectors to overexpress genes. However, chromosome-based overexpression is preferred as it avoids the use of selective pressure and reduces metabolic burden on the cell. We have constructed a series of template plasmids for λ Red-mediated Escherichia coli genome engineering. The template plasmids allow construction of genome integrating cassettes that can be used to integrate single copies of DNA sequences at predetermined sites or replace promoter regions. The constructed cassettes provide flexibility in terms of expression levels achieved and antibiotics used for selection, as well as allowing construction of marker-free strains. The modular design of the template plasmids allows replacement of genetic parts to construct new templates. Gene integration and promoter replacement using the template plasmids are illustrated. PMID:27071533

  13. Sugar metabolism in transketolase mutants of Escherichia coli.

    Science.gov (United States)

    Josephson, B L; Fraenkel, D G

    1974-06-01

    This paper continues the description of transketolase mutants of Escherichia coli; they are absolutely unable to grow on pentoses, but slightly "leaky" with respect to their aromatic requirement (B. L. Josephson and D. G. Fraenkel, 1969). Several experiments have explored the degree of leakiness and shown it to be low. There is little conversion of radioactive xylose to carbon dioxide. The labeling of ribose in cells grown on [1-(14)C]glucose and [2-(14)C]glucose accords with its origin being chiefly by the oxidative pathway. A mutant lacking both transketolase and gluconate-6-phosphate dehydrogenase has been constructed; it requires supplementation with pentose. Pentoses are inhibitory to growth of transketolase mutants, but high levels of pentose phosphates do not accumulate in this situation. Several experimental results are suggestive of regulation of metabolic flow in the oxidative branch of the hexose monophosphate shunt. PMID:4597996

  14. SOS response induces persistence to fluoroquinolones in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Tobias Dörr

    2009-12-01

    Full Text Available Bacteria can survive antibiotic treatment without acquiring heritable antibiotic resistance. We investigated persistence to the fluoroquinolone ciprofloxacin in Escherichia coli. Our data show that a majority of persisters to ciprofloxacin were formed upon exposure to the antibiotic, in a manner dependent on the SOS gene network. These findings reveal an active and inducible mechanism of persister formation mediated by the SOS response, challenging the prevailing view that persisters are pre-existing and formed purely by stochastic means. SOS-induced persistence is a novel mechanism by which cells can counteract DNA damage and promote survival to fluoroquinolones. This unique survival mechanism may be an important factor influencing the outcome of antibiotic therapy in vivo.

  15. Detergent (sodium dodecyl sulfate) shock proteins in Escherichia coli

    International Nuclear Information System (INIS)

    The protein composition of Escherichia coli W3110 grown in the presence and absence of 5% sodium dodecyl sulfate (SDS) was examined by two-dimensional gel electrophoresis. In SDS-grown cells, at least 4 proteins were turned on, 13 were turned off, 15 were elevated, and 15 were depressed. The 19 unique and elevated SDS-induced spots constituted 7.91% of the total 35S-labeled protein. There was no apparent overlap between these 19 detergent (SDS) stress proteins and those of other known bacterial stress responses. The detergent stress stimulon is a distinct and independent stimulon. Its physiological relevance probably derives from the presence of bile salts in animal gastrointestinal tracts

  16. Evidence of histidine phosphorylation in isocitrate lyase from Escherichia coli

    International Nuclear Information System (INIS)

    Escherichia coli isocitrate lyase can be phosphorylated in vitro in an ATP-dependent reaction. Partially purified extracts were incubated with γ-32P-ATP and analyzed by two-dimensional polyacrylamide gel electrophoresis followed by a Western blot and autoradiography. Radioactivity was associated with the lyase only when blotting was performed under alkaline conditions. This suggests that phosphate groups are attached to the lyase via an acid-labile P-N bond rather than a more stable P-O bond. Treatment of the lyase with diethyl pyrocarbonate, a histidine modifying agent, blocks incorporation of 32P-phosphate. Treatment with phosphoramidate, a histidine phosphorylating agent, alters the isoelectric point of the lyase suggesting that the enzyme can be phosphorylated at histidine residues. Loss of catalytic activity after treatment with potato acid phosphatase indicates that isocitrate lyase activity may be modulated by phosphorylation

  17. Signaling and sensory adaptation in Escherichia coli chemoreceptors: 2015 update.

    Science.gov (United States)

    Parkinson, John S; Hazelbauer, Gerald L; Falke, Joseph J

    2015-05-01

    Motile Escherichia coli cells track gradients of attractant and repellent chemicals in their environment with transmembrane chemoreceptor proteins. These receptors operate in cooperative arrays to produce large changes in the activity of a signaling kinase, CheA, in response to small changes in chemoeffector concentration. Recent research has provided a much deeper understanding of the structure and function of core receptor signaling complexes and the architecture of higher-order receptor arrays, which, in turn, has led to new insights into the molecular signaling mechanisms of chemoreceptor networks. Current evidence supports a new view of receptor signaling in which stimulus information travels within receptor molecules through shifts in the dynamic properties of adjoining structural elements rather than through a few discrete conformational states. PMID:25834953

  18. Uropathogenic Escherichia coli Epigenetically Manipulate Host Cell Death Pathways.

    Science.gov (United States)

    Zhang, Zhengguo; Wang, Ming; Eisel, Florian; Tchatalbachev, Svetlin; Chakraborty, Trinad; Meinhardt, Andreas; Bhushan, Sudhanshu

    2016-04-01

    Urinary tract infections caused by uropathogenic Escherichia coli (UPEC) pathovars belong to the most frequent infections in human. It is well established that UPEC can subvert innate immune responses, but the role of UPEC in interfering with host cell death pathways is not known. Here, we show that UPEC abrogates activation of the host cell prosurvival protein kinase B signaling pathway, which results in the activation of mammalian forkhead box O (FOXO) transcription factors. Although FOXOs were localized in the nucleus and showed increased DNA-binding activity, no change in the expression levels of FOXO target genes were observed. UPEC can suppress BIM expression induced by LY249002, which results in attenuation of caspase 3 activation and blockage of apoptosis. Mechanistically, BIM expression appears to be epigenetically silenced by a decrease in histone 4 acetylation at the BIM promoter site. Taken together, these results suggest that UPEC can epigenetically silence BIM expression, a molecular switch that prevents apoptosis. PMID:26621912

  19. Chromosome segregation control by Escherichia coli ObgE GTPase.

    Science.gov (United States)

    Foti, James J; Persky, Nicole S; Ferullo, Daniel J; Lovett, Susan T

    2007-07-01

    Escherichia coli cells depleted of the conserved GTPase, ObgE, show early chromosome-partitioning defects and accumulate replicated chromosomes in which the terminus regions are colocalized. Cells lacking ObgE continue to initiate replication, with a normal ratio of the origin to terminus. Localization of the SeqA DNA binding protein, normally seen as punctate foci, however, was disturbed. Depletion of ObgE also results in cell filamentation, with polyploid DNA content. Depletion of ObgE did not cause lethality, and cells recovered fully after expression of ObgE was restored. We propose a model in which ObgE is required to license chromosome segregation and subsequent cell cycle events. PMID:17578452

  20. Initiation of Replication in Escherichia coli

    DEFF Research Database (Denmark)

    Frimodt-Møller, Jakob

    The circular chromosome of Escherichia coli is replicated by two replisomes assembled at the unique origin and moving in the opposite direction until they meet in the less well defined terminus. The key protein in initiation of replication, DnaA, facilitates the unwinding of double-stranded DNA to...... single-stranded DNA in oriC. Although DnaA is able to bind both ADP and ATP, DnaA is only active in initiation when bound to ATP. Although initiation of replication, and the regulation of this, is thoroughly investigated it is still not fully understood. The overall aim of the thesis was to investigate...... the regulation of initiation, the effect on the cell when regulation fails, and if regulation was interlinked to chromosomal organization. This thesis uncovers that there exists a subtle balance between chromosome replication and reactive oxygen species (ROS) inflicted DNA damage. Thus, failure in...

  1. Functional biosynthesis of an allophycocyan beta subunit in Escherichia coli.

    Science.gov (United States)

    Ge, Baosheng; Sun, Haixiang; Feng, Yang; Yang, Jinying; Qin, Song

    2009-03-01

    Allophycocyanin is a phycobiliprotein with various biological and pharmacological properties. An expression vector was constructed using CpeS as the bilin lyase for the allophycocyanin beta subunit, resulting in overexpression of a fluorescent allophycocyanin beta-subunit in Escherichia coli. A high-density cell culture was developed using a continuous feeding strategy. After 16 h of culture, the dry cell density reached 21.4 g l(-1), the expression of the allophycocyanin beta-subunit was 0.86 g l(-1) broth, and the relative chromoprotein yield was 81.4%. The recombinant protein showed spectral features similar to native allophycocyanin, which provide an efficient methodology for large-scale production of this valuable fluorescent protein. PMID:19269586

  2. Renal abscess due to Escherichia coli in a child

    Directory of Open Access Journals (Sweden)

    V P Baradkar

    2011-01-01

    Full Text Available Among the various intraabdominal abscesses, renal abscess is a rare entity, especially in children and accounts for a number of cases of "missed diagnoses." Drainage of pus and appropriate antibiotic therapy is the gold standard for treatment. Here we report a case of left renal abscess in a 6-year-old female child secondary to renal calculus. The patient presented with abdominal pain and mild fever for three months and the diagnosis was made by X-ray in the kidney, ureter and bladder (KUB region, intravenous pyelography and ultrasonography of the abdomen. Escherichia coli was isolated from pus obtained by percutaneous drainage under sonographic guidance. The patient responded to intra-venous ceftriaxone, amikacin, and percutaneous drainage.

  3. Escherichia coli activity characterization using a laser dynamic speckle technique

    CERN Document Server

    Ramírez-Miquet, Evelio E; Contreras-Alarcón, Orestes R

    2012-01-01

    The results of applying a laser dynamic speckle technique to characterize bacterial activity are presented. The speckle activity was detected in two-compartment Petri dishes. One compartment was inoculated and the other one was left as a control blank. The speckled images were processed by the recently reported temporal difference method. Three inoculums of 0.3, 0.5, and 0.7 McFarland units of cell concentration were tested; each inoculum was tested twice for a total of six experiments. The dependences on time of the mean activity, the standard deviation of activity and other descriptors of the speckle pattern evolution were calculated for both the inoculated compartment and the blank. In conclusion the proposed dynamic speckle technique allows characterizing the activity of Escherichia coli bacteria in solid medium.

  4. Analysis of resynthesis tracts in repaired Escherichia coli deoxyribonucleic acid

    International Nuclear Information System (INIS)

    Excision repair of ultraviolet radiation-induced damage in a wild-type strain of Escherichia coli has been examined, using two methods for characterizing the resynthesis step of the repair process. Comparison of data obtained after both isopycnic analysis of repaired deoxyribonucleic acid and sedimentation velocity analysis of deoxyribonucleic acid after selective photolysis of bromouracil-containing repaired regions has shown that the repaired deoxyribonucleic acid molecules contain a semicontinuous distribution of sizes of repair tracts. Further analysis of our data suggests two major classes of repair patches, one about 20 to 40 nucleotides in length, and the other containing 1600 to 2000 nucleotides. Under the conditions employed, approximately 2 to 10% of the fully repaired regions are long repair patches

  5. Improvement of escherichia coli for lysine overproduction through mutagenesis

    International Nuclear Information System (INIS)

    Bacterial isolates of Escherichia coli were obtained from the irrigation channel water. One of the isolates designated SW30 NIAB produced glutamic acid in cane molasses medium and was selected for further improvement for lysine overproduction. The cells of this strain were treated with a dose of 100 u/ g/ml of NTG(N-methyl-N-nitro-N-Nitrosoguanidine), for 90 minutes. From the cell population (3x108 cells/ml) exposed to NTG, only 1-2 percent cells survived and produced colonies. Independent colonies, 100 of them that survived the dose, were secured and subcultured. These were further screened against AEC (S-(2-aminoethyl)-L-cysteine) resistance on minimal agar medium MM-12. Among these 100 colonies, 10 proved resistant to AEC at a dose of 1000 ug/ml, and out of 10, three were lysine producers and produced 0.1-0.5 gm/ltr of lysine in L-6 medium. (author)

  6. Prevalence of antimicrobial resistance in Escherichia coli and Klebsiella spp. in rural South India.

    Science.gov (United States)

    Sekar, Ramalingam; Mythreyee, Manoharan; Srivani, Seetharaman; Amudhan, Murugesan

    2016-06-01

    The emergence and dissemination of antimicrobial resistance (AMR) is an important public health problem as resistant organisms cause difficult-to-treat infections. In this study, the prevalence of AMR in Escherichia coli and Klebsiella spp. in rural South India was examined in order to aid empirical therapy. A cross-sectional prospective study was conducted during the period from January 2012 to December 2014. Routine clinical isolates of E. coli and Klebsiella spp. were tested for antimicrobial susceptibility to β-lactams, aminoglycosides, fluoroquinolones, tetracyclines, colistin and nitrofurantoin by the Kirby-Bauer disk diffusion method and the data were documented and analyzed with one per patient analysis using WHONET software. A total of 2292 non-duplicate clinical isolates were recovered during the study period, including 1338 E. coli and 954 Klebsiella spp. The prevalence of AMR in the total isolates was as follows: amikacin, 17.3%; ertapenem, 14.4%; doripenem, 4.5%; colistin, 13.2%; and tigecycline, 4.1%. The study results indicate a high prevalence of carbapenem resistance in Klebsiella spp. especially from pus and urinary isolates, whilst the prevalence of aztreonam and fluoroquinolone resistance was very high in E. coli. PMID:27436473

  7. [Diarrheagenic Escherichia coli associated with acute diarrhea in children of Cumaná, Venezuela].

    Science.gov (United States)

    Hannaoui, Erika; Villalobos, Luz; Martínez, Rosa; Maldonado, Antonio; Hagel, Isabel; Bastardo, Jesús

    2010-12-01

    To establish the prevalence of strains of diarrheagenic Escherichia coli (DEC) associated to acute diarrhea in children of Cumaná, Venezuela, stool samples were taken from 200 children aged ADEC). From 169 E. coli, isolates we determined by PCR 10.65% positive for EPEC (1.18% "typical", 9.47% "atypical"); ETEC (5.91%); EAEC (1.78 %), EIEC (0.59%). There were no statistically significant differences regarding the frequency of each "pathotype" in relation to age, but it did occur when related to the sex (p<0.05). The most relevant clinical features were: fever, vomiting and abdominal pain and the greatest percentage of children affected were of the working and marginal classes. These results shown that the strains of DEC are important etiological agents in acute infectious diarrhea in children of Cumaná. PMID:21365876

  8. 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...... and ompT (outer membrane protease). Slight additional virulence profile variation was evident, particularly within a minor diarrhea-associated subset (biotype C). However, in contrast to the clonal group's fairly stable virulence profiles over the past 30+ years, during the same interval the clonal...

  9. Evaluation of Petrifilm™ Select E. coli Count Plate medium to discriminate antimicrobial resistant Escherichia coli

    Directory of Open Access Journals (Sweden)

    Jensen Lars

    2008-09-01

    Full Text Available Abstract Background Screening and enumeration of antimicrobial resistant Escherichia coli directly from samples is needed to identify emerging resistant clones and obtain quantitative data for risk assessment. Aim of this study was to evaluate the performance of 3M™ Petrifilm™ Select E. coli Count Plate (SEC plate supplemented with antimicrobials to discriminate antimicrobial-resistant and non-resistant E. coli. Method A range of E. coli isolates were tested by agar dilution method comparing the Minimal Inhibitory Concentration (MIC for eight antimicrobials obtained by Mueller-Hinton II agar, MacConkey agar and SEC plates. Kappa statistics was used to assess the levels of agreement when classifying strains as resistant, intermediate or susceptible. Results SEC plate showed that 74% of all strains agreed within ± 1 log2 dilution when comparing MICs with Mueller-Hinton II media. High agreement levels were found for gentamicin, ampicillin, chloramphenicol and cefotaxime, resulting in a kappa value of 0.9 and 100% agreement within ± 1 log2 dilution. Significant variances were observed for oxytetracycline and sulphamethoxazole. Further tests showed that the observed discrepancy in classification of susceptibility to oxytetracycline by the two media could be overcome when a plate-dependent breakpoint of 64 mg/L was used for SEC plates. For sulphamethoxazole, SEC plates provided unacceptably high MICs. Conclusion SEC plates showed good agreement with Mueller-Hinton II agar in MIC studies and can be used to screen and discriminate resistant E. coli for ampicillin, cephalothin, streptomycin, chloramphenicol, cefotaxime and gentamicin using CLSI standardized breakpoints, but not for sulphamethoxazole. SEC plates can also be used to discriminate oxytetracycline-resistant E. coli if a plate-dependent breakpoint value of 64 mg/L is used.

  10. Prevalence of Shiga toxin genes and intimin genes in uropathogenic Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    Kobra Abbasi; Elahe Tajbakhsh

    2015-01-01

    Objective:To identifystx1, stx2 andeaeA genes inEscherichia coli (E. coli) strains isolated from urine samples in Shahrekord, Iran. Methods: In this cross study a total of 147 middle urine samples from patients with symptoms of urinary tract infection (UTI), referred to clinical laboratories of Shahrekord were studied. Taken samples were cultured to detect Shigatoxin-producing strains and finally 76E. coli isolates were identified using the standard biochemical tests as well as the selective and differential media. The multiplexPCR method was used to evaluate the presence ofstx1, stx2 andeaeA genes.DNA bacteria extraction was performed by boiling and thenPCR was performed in the presence of specific primers. Results: A total of 147 urine samples were collected from patients with suspectedUTI, and 76 samples (51.70%) were diagnosed withE. coli. Among 76 studied isolations ofE. coli, 3 (3.94%) had a positive reaction to lactose and negative reaction to sorbitol. In the female gender,stx1 gene that shown in the samples was related to 30–39 age group. In the other sample related to 20–29 age group,stx1 andeaeA gene were shown. But in male genderstx1 gene was reported in the sample related to 40–49 age group.stx1, stx2 andeaeA genes were not observed together in any samples. Conclusions: Isolation of Shiga toxin-producingE. coli strains has great importance because of the possibility of clinical complications such as hemolytic-uremic syndrome.

  11. Invariant distribution of promoter activities in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Alon Zaslaver

    2009-10-01

    Full Text Available Cells need to allocate their limited resources to express a wide range of genes. To understand how Escherichia coli partitions its transcriptional resources between its different promoters, we employ a robotic assay using a comprehensive reporter strain library for E. coli to measure promoter activity on a genomic scale at high-temporal resolution and accuracy. This allows continuous tracking of promoter activity as cells change their growth rate from exponential to stationary phase in different media. We find a heavy-tailed distribution of promoter activities, with promoter activities spanning several orders of magnitude. While the shape of the distribution is almost completely independent of the growth conditions, the identity of the promoters expressed at different levels does depend on them. Translation machinery genes, however, keep the same relative expression levels in the distribution across conditions, and their fractional promoter activity tracks growth rate tightly. We present a simple optimization model for resource allocation which suggests that the observed invariant distributions might maximize growth rate. These invariant features of the distribution of promoter activities may suggest design constraints that shape the allocation of transcriptional resources.

  12. Molecular evolution of the Escherichia coli chromosome. IV. Sequence comparisons.

    Science.gov (United States)

    Milkman, R; Bridges, M M

    1993-03-01

    DNA sequences have been compared in a 4,400-bp region for Escherichia coli K12 and 36 ECOR strains. Discontinuities in degree of similarity, previously inferred, are confirmed in detail. Three clonal frames are described on the basis of the present local high-resolution data, as well as previous analyses of restriction fragment length polymorphism (RFLP) and of multilocus enzyme electrophoresis (MLEE) covering small regions more widely dispersed on the chromosome. These three approaches show important consistency. The data illustrate the fact that, in the limited context of intraspecific genomic sequence variation, clonality and homology are synonymous. Two estimable quantitative properties are defined: recency of common ancestry (the reciprocal of the log10 of the number of generations since the most recent common ancestor), and the number of nucleotide pairs over which a given recency of common ancestry applies. In principle, these parameters are measures of the degree and physical extent of homology. The small size of apparent recombinational replacements, together with the observation that they occasionally occur in discontinuous series, raises the question of whether they result from the superimposition of replacements of much larger size (as expected from an elementary interpretation of conjugation and transduction in experimental E. coli systems) or via an alternative mechanism. Length polymorphisms of several sorts are described. PMID:8095913

  13. Increased cytoplasm viscosity hampers aggregate polar segregation in Escherichia coli.

    Science.gov (United States)

    Oliveira, Samuel M D; Neeli-Venkata, Ramakanth; Goncalves, Nadia S M; Santinha, João A; Martins, Leonardo; Tran, Huy; Mäkelä, Jarno; Gupta, Abhishekh; Barandas, Marilia; Häkkinen, Antti; Lloyd-Price, Jason; Fonseca, José M; Ribeiro, Andre S

    2016-02-01

    In Escherichia coli, under optimal conditions, protein aggregates associated with cellular aging are excluded from midcell by the nucleoid. We study the functionality of this process under sub-optimal temperatures from population and time lapse images of individual cells and aggregates and nucleoids within. We show that, as temperature decreases, aggregates become homogeneously distributed and uncorrelated with nucleoid size and location. We present evidence that this is due to increased cytoplasm viscosity, which weakens the anisotropy in aggregate displacements at the nucleoid borders that is responsible for their preference for polar localisation. Next, we show that in plasmolysed cells, which have increased cytoplasm viscosity, aggregates are also not preferentially located at the poles. Finally, we show that the inability of cells with increased viscosity to exclude aggregates from midcell results in enhanced aggregate concentration in between the nucleoids in cells close to dividing. This weakens the asymmetries in aggregate numbers between sister cells of subsequent generations required for rejuvenating cell lineages. We conclude that the process of exclusion of protein aggregates from midcell is not immune to stress conditions affecting the cytoplasm viscosity. The findings contribute to our understanding of E. coli's internal organisation and functioning, and its fragility to stressful conditions. PMID:26507787

  14. Composite analysis for Escherichia coli at coastal beaches

    Science.gov (United States)

    Bertke, E.E.

    2007-01-01

    At some coastal beaches, concentrations of fecal-indicator bacteria can differ substantially between multiple points at the same beach at the same time. Because of this spatial variability, the recreational water quality at beaches is sometimes determined by stratifying a beach into several areas and collecting a sample from each area to analyze for the concentration of fecal-indicator bacteria. The average concentration of bacteria from those points is often used to compare to the recreational standard for advisory postings. Alternatively, if funds are limited, a single sample is collected to represent the beach. Compositing the samples collected from each section of the beach may yield equally accurate data as averaging concentrations from multiple points, at a reduced cost. In the study described herein, water samples were collected at multiple points from three Lake Erie beaches and analyzed for Escherichia coli on modified mTEC agar (EPA Method 1603). From the multiple-point samples, a composite sample (n = 116) was formed at each beach by combining equal aliquots of well-mixed water from each point. Results from this study indicate that E. coli concentrations from the arithmetic average of multiple-point samples and from composited samples are not significantly different (t = 1.59, p = 0.1139) and yield similar measures of recreational water quality; additionally, composite samples could result in a significant cost savings.

  15. Light induced DEP for immobilizing and orienting Escherichia coli bacteria

    Science.gov (United States)

    Miccio, Lisa; Marchesano, Valentina; Mugnano, Martina; Grilli, Simonetta; Ferraro, Pietro

    2016-01-01

    Manipulating bacteria and understanding their behavior when interacting with different substrates are of fundamental importance for patterning, detection, and any other topics related to health-care, food-enterprise, etc. Here, we adopt an innovative dielectrophoretic (DEP) approach based on electrode-free DEP for investigating smart but simple strategies for immobilization and orientation of bacteria. Escherichia coli DH5-alpha strain has been selected as subject of the study. The light induced DEP is achieved through ferroelectric iron-doped lithium niobate crystals used as substrates. Due to the photorefractive (PR) property of such material, suitable light patterns allow writing spatial-charges-distribution inside its volume and the resultant electric fields are able to immobilize E. coli on the surface. The experiments showed that, after laser irradiation, about 80% of bacteria is blocked and oriented along a particular direction on the crystals within an area of few square centimeters. The investigation presented here could open the way for detection or patterning applications based on a new driving mechanism. Future perspectives also include the possibility to actively switch by light the DEP forces, through the writing/erasing characteristic of PR fields, to dynamically control biofilm spatial structure and arrangement.

  16. Efflux transporter engineering markedly improves amorphadiene production in Escherichia coli.

    Science.gov (United States)

    Zhang, Congqiang; Chen, Xixian; Stephanopoulos, Gregory; Too, Heng-Phon

    2016-08-01

    Metabolic engineering aims at altering cellular metabolism to produce valuable products at high yields and titers. Achieving high titers and productivity can be challenging if final products are largely accumulated intracellularly. A potential solution to this problem is to facilitate the export of these substances from cells by membrane transporters. Amorphadiene, the precursor of antimalarial drug artemisinin, is known to be secreted from Escherichia coli overexpressing the biosynthetic pathway. In order to assess the involvement of various endogenous efflux pumps in amorphadiene transport, the effects of single gene deletion of 16 known multidrug-resistant membrane efflux transporters were examined. The outer membrane protein TolC was found to be intimately involved in amorphadiene efflux. The overexpression of tolC together with ABC family transporters (macAB) or MFS family transporters (emrAB or emrKY) enhanced amorphadiene titer by more than threefold. In addition, the overexpression of transporters in the lipopolysaccharide transport system (msbA, lptD, lptCABFG) was found to improve amorphadiene production. As efflux transporters often have a wide range of substrate specificity, the multiple families of transporters were co-expressed and synergistic benefits were observed in amorphadiene production. This strategy of screening and then rationally engineering transporters can be used to improve the production of other valuable compounds in E. coli. Biotechnol. Bioeng. 2016;113: 1755-1763. © 2016 Wiley Periodicals, Inc. PMID:26804325

  17. Improvements In Ethanologenic Escherichia Coli and Klebsiella Oxytoca

    Energy Technology Data Exchange (ETDEWEB)

    Dr. David Nunn

    2010-09-30

    The current Verenium cellulosic ethanol process is based on the dilute-acid pretreatment of a biomass feedstock, followed by a two-stage fermentation of the pentose sugar-containing hydrolysate by a genetically modified ethanologenic Escherichia coli strain and a separate simultaneous saccharification-fermentation (SSF) of the cellulosic fraction by a genetically modified ethanologenic Klebsiella oxytoca strain and a fungal enzyme cocktail. In order to reduce unit operations and produce a fermentation beer with higher ethanol concentrations to reduce distillation costs, we have proposed to develop a simultaneous saccharification co-fermentation (SScF) process, where the fermentation of the pentose-containing hydrolysate and cellulosic fraction occurs within the same fermentation vessel. In order to accomplish this goal, improvements in the ethanologens must be made to address a number of issues that arise, including improved hydrolysate tolerance, co-fermentation of the pentose and hexose sugars and increased ethanol tolerance. Using a variety of approaches, including transcriptomics, strain adaptation, metagenomics and directed evolution, this work describes the efforts of a team of scientists from Verenium, University of Florida, Massachusetts Institute of Technology and Genomatica to improve the E. coli and K. oxytoca ethanologens to meet these requirements.

  18. Structure of CFA/I fimbriae from enterotoxigenic Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yong-Fu; Poole, Steven; Nishio, Kazuya; Jang, Ken; Rasulova, Fatima; McVeigh, Annette; Savarino, Stephen J.; Xia, Di; Bullitt, Esther; (BU-M); (NIH); (NMRC)

    2009-10-21

    Adhesion pili (fimbriae) play a critical role in initiating the events that lead to intestinal colonization and diarrheal disease by enterotoxigenic Escherichia coli (ETEC), an E. coli pathotype that inflicts an enormous global disease burden. We elucidate atomic structures of an ETEC major pilin subunit, CfaB, from colonization factor antigen I (CFA/I) fimbriae. These data are used to construct models for 2 morphological forms of CFA/I fimbriae that are both observed in vivo: the helical filament into which it is typically assembled, and an extended, unwound conformation. Modeling and corroborative mutational data indicate that proline isomerization is involved in the conversion between these helical and extended forms. Our findings affirm the strong structural similarities seen between class 5 fimbriae (from bacteria primarily causing gastrointestinal disease) and class 1 pili (from bacteria that cause urinary, respiratory, and other infections) in the absence of significant primary sequence similarity. They also suggest that morphological and biochemical differences between fimbrial types, regardless of class, provide structural specialization that facilitates survival of each bacterial pathotype in its preferred host microenvironment. Last, we present structural evidence for bacterial use of antigenic variation to evade host immune responses, in that residues occupying the predicted surface-exposed face of CfaB and related class 5 pilins show much higher genetic sequence variability than the remainder of the pilin protein.

  19. Biosynthesis of fluorescent cyanobacterial allophycocyanin trimer in Escherichia coli.

    Science.gov (United States)

    Liu, Shaofang; Chen, Yingjie; Lu, Yandu; Chen, Huaxin; Li, Fuchao; Qin, Song

    2010-08-01

    Allophycocyanin (APC), a cyanobacterial photosynthetic phycobiliprotein, functions in energy transfer as a light-harvesting protein. One of the prominent spectroscopic characteristics of APC is a strong red-shift in the absorption and emission maxima when monomers are assembled into a trimer. Previously, holo-APC alpha and beta subunits (holo-ApcA and ApcB) were successfully synthesized in Escherichia coli. In this study, both holo-subunits from Synechocystis sp. PCC 6803 were co-expressed in E. coli, and found to self-assemble into trimers. The recombinant APC trimer was purified by metal affinity and size-exclusion chromatography, and had a native structure identical to native APC, as determined by characteristic spectroscopic measurements, fluorescence quantum yield, tryptic digestion analysis, and molecular weight measurements. Combined with results from a study in which only the monomer was formed, our results indicate that bilin synthesis and the subsequent attachment to apo-subunits are important for the successful assembly of APC trimers. This is the first study to report on the assembly of recombinant ApcA and ApcB into a trimer with native structure. Our study provides a promising method for producing better fluorescent tags, as well as a method to facilitate the genetic analysis of APC trimer assembly and biological function. PMID:20607408

  20. Scalable purification of Bacillus anthracis protective antigen from Escherichia coli.

    Science.gov (United States)

    Gwinn, William; Zhang, Mei; Mon, Sandii; Sampey, Darryl; Zukauskas, David; Kassebaum, Corby; Zmuda, Jonathan F; Tsai, Amos; Laird, Michael W

    2006-01-01

    The anthrax toxin consists of three proteins, protective antigen (PA), lethal factor, and edema factor that are produced by the Gram-positive bacterium, Bacillus anthracis. Current vaccines against anthrax use PA as their primary component. In this study, we developed a scalable process to produce and purify multi-gram quantities of highly pure, recombinant PA (rPA) from Escherichia coli. The rPA protein was produced in a 50-L fermentor and purified to >99% purity using anion-exchange, hydrophobic interaction, and hydroxyapatite chromatography. The final yield of purified rPA from medium cell density fermentations resulted in approximately 2.7 g of rPA per kg of cell paste (approximately 270 mg/L) of highly pure, biologically active rPA protein. The results presented here exhibit the ability to generate multi-gram quantities of rPA from E. coli that may be used for the development of new anthrax vaccines and anthrax therapeutics. PMID:15935696

  1. Pattern Formation of Bacterial Colonies by Escherichia coli

    Science.gov (United States)

    Tokita, Rie; Katoh, Takaki; Maeda, Yusuke; Wakita, Jun-ichi; Sano, Masaki; Matsuyama, Tohey; Matsushita, Mitsugu

    2009-07-01

    We have studied the morphological diversity and change in bacterial colonies, using the bacterial species Escherichia coli, as a function of both agar concentration Ca and nutrient concentration Cn. We observed various colony patterns, classified them into four types by pattern characteristics and established a morphological diagram by dividing it into four regions. They are regions A [diffusion-limited aggregation (DLA)-like], B (Eden-like), C (concentric-ring), and D (fluid-spreading). In particular, we have observed a concentric-ring colony growth for E. coli. We focused on the periodic growth in region C and obtained the following results: (i) A colony grows cyclically with the growing front repeating an advance (migration phase) and a momentary rest (consolidation phase) alternately. (ii) The growth width L and the bulge width W in one cycle decrease asymptotically to certain values, when Ca is increased. (iii) L does not depend on Cn, while W is an increasing function of Cn. Plausible mechanisms are proposed to explain the experimental results, by comparing them with those obtained for other bacterial species such as Proteus mirabilis and Bacillus subtilis.

  2. Secretion of Alpha-Hemolysin by Escherichia coli Disrupts Tight Junctions in Ulcerative Colitis Patients

    OpenAIRE

    Mirsepasi-Lauridsen, Hengameh Chloé; Du, Zhengyu; Struve, Carsten; Charbon, Godefroid; Karczewski, Jurgen; Krogfelt, Karen Angeliki; Petersen, Andreas Munk; Wells, Jerry M

    2016-01-01

    Objectives: The potential of Escherichia coli (E. coli) isolated from inflammatory bowel disease (IBD) patients to damage the integrity of the intestinal epithelium was investigated. Methods: E. coli strains isolated from patients with ulcerative colitis (UC) and healthy controls were tested for virulence capacity by molecular techniques and cytotoxic assays and transepithelial electric resistance (TER). E. coli isolate p19A was selected, and deletion mutants were created for alpha-hemolysin ...

  3. The Association of Virulence Determinants of Uropathogenic Escherichia coli With Antibiotic Resistance

    OpenAIRE

    Sara Asadi; Mohammad Kargar; Kavous Solhjoo; Akram Najafi; Sadegh Ghorbani-Dalini

    2014-01-01

    Background: The emergence of antimicrobial resistant strains of Escherichia coli has raised considerable interest in understanding the diversity and epidemiology of E. coli infections in humans. Virulence factors of E. coli determine the specific infections caused by this microorganism. Objectives: This study aimed to determine the prevalence of eight E. coli virulence factors and their association with antimicrobial resistance in bacteria isolated from patients with urinary tract infecti...

  4. Relative effects of bacterial and protozoan predators on survival of Escherichia coli in estuarine water samples.

    OpenAIRE

    McCambridge, J; McMeekin, T A

    1980-01-01

    The relative effect of protozoan and bacterial predators on the survival of Escherichia coli in estuarine water samples was examined. Predacious protozoa exerted their major influence on E. coli destruction during the first 2 days of a 10-day-decline period. Inhibition of protozoa after day 2 had little effect on E. coli survival. Bacterial predators also contributed to E. coli destruction but in natural estuarine water samples were maintained at lower levels due to "grazing" by predacious pr...

  5. Involvement of Focal Adhesion Kinase in Escherichia coli Invasion of Human Brain Microvascular Endothelial Cells

    OpenAIRE

    Reddy, Marpadga A; Wass, Carol A.; Kim, Kwang Sik; Schlaepfer, David D.; Prasadarao, Nemani V.

    2000-01-01

    Escherichia coli K1 traversal across the blood-brain barrier is an essential step in the pathogenesis of neonatal meningitis. We have previously shown that invasive E. coli promotes the actin rearrangement of brain microvascular endothelial cells (BMEC), which constitute a lining of the blood-brain barrier, for invasion. However, signal transduction mechanisms involved in E. coli invasion are not defined. In this report we show that tyrosine kinases play a major role in E. coli invasion of hu...

  6. A Survey for Escherichia coli Virulence Factors in Asymptomatic Free-Ranging Parrots

    OpenAIRE

    André Becker Saidenberg; Neiva Maria Robaldo Guedes; Gláucia Helena Fernandes Seixas; Mariangela da Costa Allgayer; Erica Pacífico de Assis; Luis Fabio Silveira; Priscilla Anne Melville; Nilson Roberti Benites

    2012-01-01

    Parrots in captivity are frequently affected by Escherichia coli (E. coli) infections. The objective of this study was to collect information on the carrier state for E. coli pathotypes in asymptomatic free-ranging parrots. Cloacal swabs were collected from nestlings of Hyacinth, Lear’s macaws and Blue-fronted Amazon parrots and tested by polymerase chain reaction (PCR) for virulence factors commonly found in enteropathogenic, avian pathogenic, and uropathogenic E. coli strains. In total, 44 ...

  7. Production of pili, hemolysin and siderophores in the urinary isolates of Escherichia coli

    OpenAIRE

    Marković Tatjana; Šmitran Aleksandra; Petković Miroslav

    2013-01-01

    Introduction. Escherichia coli (E. coli) are the most frequent cause of the urinary tract infections. Uropathogenic E. coli (UPEC) produce virulence factors which enable them to survive in the urinary tract and cause an infection. Objective. The objective of this study was to determine phenotype characterization of E. coli isolated from outpatients’ urine in the region of Banja Luka over three-year period. In line with the objective, the following research tasks were set up: determining...

  8. Vergleichende geno- und phänotypische Charakterisierung von Escherichia coli aus Menschen, Hausschweinen und Wildtieren

    OpenAIRE

    Frömmel, Ulrike

    2014-01-01

    Escherichia (E.) coli ist als kommensales Bakterium ein wichtiger Bestandteil des Mikrobioms von Säugern, jedoch zudem der häufigste Infektionserreger des Menschen. Entsprechend des Infektionsortes werden intestinal (InPEC) und extraintestinal pathogene E. coli (ExPEC) unterschieden. Die Pathogenese von E. coli-Infektionen ist durch Virulenzfaktoren determiniert, welche von jeweils spezifischen virulenzassoziierten Genen (inVAGs und exVAGs) kodiert werden. Häufig werden exVAGs auch in E. coli...

  9. Detection and Characterization of Diarrheagenic Escherichia coli from Young Children in Hanoi, Vietnam

    OpenAIRE

    Nguyen, Trung Vu; Le Van, Phung; Le Huy, Chinh; Gia, Khanh Nguyen; Weintraub, Andrej

    2005-01-01

    Diarrhea continues to be one of the most common causes of morbidity and mortality among infants and children in developing countries. Escherichia coli is an emerging agent among pathogens that cause diarrhea. The development of a highly applicable technique for the detection of different categories of diarrheagenic E. coli is important. We have used multiplex PCR by combining eight primer pairs specific for enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. ...

  10. Estimating Escherichia coli loads in streams based on various physical, chemical, and biological factors

    OpenAIRE

    Dwivedi, Dipankar; Mohanty, Binayak P.; Lesikar, Bruce J.

    2013-01-01

    Microbes have been identified as a major contaminant of water resources. Escherichia coli (E. coli) is a commonly used indicator organism. It is well recognized that the fate of E. coli in surface water systems is governed by multiple physical, chemical, and biological factors. The aim of this work is to provide insight into the physical, chemical, and biological factors along with their interactions that are critical in the estimation of E. coli loads in surface streams. There are various mo...

  11. Biosynthesis of odd-chain fatty alcohols in Escherichia coli.

    Science.gov (United States)

    Cao, Ying-Xiu; Xiao, Wen-Hai; Liu, Duo; Zhang, Jin-Lai; Ding, Ming-Zhu; Yuan, Ying-Jin

    2015-05-01

    Engineered microbes offer the opportunity to design and implement artificial molecular pathways for renewable production of tailored chemical commodities. Targeted biosynthesis of odd-chain fatty alcohols is very challenging in microbe, due to the specificity of fatty acids synthase for two-carbon unit elongation. Here, we developed a novel strategy to directly tailor carbon number in fatty aldehydes formation step by incorporating α-dioxygenase (αDOX) from Oryza sativa (rice) into Escherichia coli αDOX oxidizes Cn fatty acids (even-chain) to form Cn-1 fatty aldehydes (odd-chain). Through combining αDOX with fatty acyl-acyl carrier protein (-ACP) thioesterase (TE) and aldehyde reductase (AHR), the medium odd-chain fatty alcohols profile (C11, C13, C15) was firstly established in E. coli. Also, medium even-chain alkanes (C12, C14) were obtained by substitution of AHR to aldehyde decarbonylase (AD). The titer of odd-chain fatty alcohols was improved from 7.4mg/L to 101.5mg/L in tube cultivation by means of fine-tuning endogenous fatty acyl-ACP TE (TesA'), αDOX, AHRs and the genes involved in fatty acids metabolism pathway. Through high cell density fed-batch fermentation, a titer of 1.95g/L odd-chain fatty alcohols was achieved, which was the highest reported titer in E. coli. Our system has greatly expanded the current microbial fatty alcohols profile that provides a new brand solution for producing complex and desired molecules in microbes. PMID:25773521

  12. Inhibition of Escherichia coli ATP synthase by amphibian antimicrobial peptides.

    Science.gov (United States)

    Laughlin, Thomas F; Ahmad, Zulfiqar

    2010-04-01

    Previously melittin, the alpha-helical basic honey bee venom peptide, was shown to inhibit F(1)-ATPase by binding at the beta-subunit DELSEED motif of F(1)F(o)-ATP synthase. Herein, we present the inhibitory effects of the basic alpha-helical amphibian antimicrobial peptides, ascaphin-8, aurein 2.2, aurein 2.3, carein 1.8, carein 1.9, citropin 1.1, dermaseptin, maculatin 1.1, maganin II, MRP, or XT-7, on purified F(1) and membrane bound F(1)F(0)Escherichia coli ATP synthase. We found that the extent of inhibition by amphibian peptides is variable. Whereas MRP-amide inhibited ATPase essentially completely (approximately 96% inhibition), carein 1.8 did not inhibit at all (0% inhibition). Inhibition by other peptides was partial with a range of approximately 13-70%. MRP-amide was also the most potent inhibitor on molar scale (IC(50) approximately 3.25 microM). Presence of an amide group at the c-terminal of peptides was found to be critical in exerting potent inhibition of ATP synthase ( approximately 20-40% additional inhibition). Inhibition was fully reversible and found to be identical in both F(1)F(0) membrane preparations as well as in isolated purified F(1). Interestingly, growth of E. coli was abrogated in the presence of ascaphin-8, aurein 2.2, aurein 2.3, citropin 1.1, dermaseptin, magainin II-amide, MRP, MRP-amide, melittin, or melittin-amide but was unaffected in the presence of carein 1.8, carein 1.9, maculatin 1.1, magainin II, or XT-7. Hence inhibition of F(1)-ATPase and E. coli cell growth by amphibian antimicrobial peptides suggests that their antimicrobial/anticancer properties are in part linked to their actions on ATP synthase. PMID:20100509

  13. A direct detection of Escherichia coli genomic DNA using gold nanoprobes

    Directory of Open Access Journals (Sweden)

    Padmavathy

    2012-02-01

    Full Text Available Abstract Background In situation like diagnosis of clinical and forensic samples there exists a need for highly sensitive, rapid and specific DNA detection methods. Though conventional DNA amplification using PCR can provide fast results, it is not widely practised in diagnostic laboratories partially because it requires skilled personnel and expensive equipment. To overcome these limitations nanoparticles have been explored as signalling probes for ultrasensitive DNA detection that can be used in field applications. Among the nanomaterials, gold nanoparticles (AuNPs have been extensively used mainly because of its optical property and ability to get functionalized with a variety of biomolecules. Results We report a protocol for the use of gold nanoparticles functionalized with single stranded oligonucleotide (AuNP- oligo probe as visual detection probes for rapid and specific detection of Escherichia coli. The AuNP- oligo probe on hybridization with target DNA containing complementary sequences remains red whereas test samples without complementary DNA sequences to the probe turns purple due to acid induced aggregation of AuNP- oligo probes. The color change of the solution is observed visually by naked eye demonstrating direct and rapid detection of the pathogenic Escherichia coli from its genomic DNA without the need for PCR amplification. The limit of detection was ~54 ng for unamplified genomic DNA. The method requires less than 30 minutes to complete after genomic DNA extraction. However, by using unamplified enzymatic digested genomic DNA, the detection limit of 11.4 ng was attained. Results of UV-Vis spectroscopic measurement and AFM imaging further support the hypothesis of aggregation based visual discrimination. To elucidate its utility in medical diagnostic, the assay was validated on clinical strains of pathogenic Escherichia coli obtained from local hospitals and spiked urine samples. It was found to be 100% sensitive and proves to

  14. Probiotic Escherichia coli Nissle 1917 reduces growth, Shiga toxin expression, release and thus cytotoxicity of enterohemorrhagic Escherichia coli.

    Science.gov (United States)

    Mohsin, Mashkoor; Guenther, Sebastian; Schierack, Peter; Tedin, Karsten; Wieler, Lothar H

    2015-01-01

    Due to increased release or production of Shiga toxin by Enterohemorrhagic Escherichia coli (EHEC) after exposure to antimicrobial agents, the role of antimicrobial agents in EHEC mediated infections remains controversial. Probiotics are therefore rapidly gaining interest as an alternate therapeutic option. The well-known probiotic strain Escherichia coli Nissle 1917 (EcN) was tested in vitro to determine its probiotic effects on growth, Shiga toxin (Stx) gene expression, Stx amount and associated cytotoxicity on the most important EHEC strains of serotype O104:H4 and O157:H7. Following co-culture of EcN:EHEC in broth for 4 and 24 h, the probiotic effects on EHEC growth, toxin gene expression, Stx amount and cytotoxicity were determined using quantitative real time-PCR, Stx-ELISA and Vero cytotoxicity assays. Probiotic EcN strongly reduced EHEC numbers (cfu) of O104:H4 up to (68%) and O157:H7 to (72.2%) (pcoli strain MG1655 had no effect on EHEC growth. The level of stx expression was significantly down-regulated, particularly for the stx2a gene. The stx down-regulation in EcN co-culture was not due to reduced numbers of EHEC. A significant inhibition in Stx amounts and cytotoxicity were also observed in sterile supernatants of EcN:EHEC co-cultures. These findings indicate that probiotic EcN displays strong inhibitory effects on growth, Shiga toxin gene expression, amount and cytotoxicity of EHEC strains. Thus, EcN may be considered as a putative therapeutic candidate, in particular against EHEC O104:H4 and O157:H7. PMID:25465158

  15. Virulence patterns in a murine sepsis model of ST131 Escherichia coli clinical isolates belonging to serotypes O25b:H4 and O16:H5 are associated to specific virotypes.

    Directory of Open Access Journals (Sweden)

    Azucena Mora

    Full Text Available Escherichia coli sequence type (ST131 is an emerging disseminated public health threat implicated in multidrug-resistant extraintestinal infections worldwide. Although the majority of ST131 isolates belong to O25b:H4 serotype, new variants with different serotypes, STs using the discriminative multilocus sequence typing scheme of Pasteur Institute, and virulence-gene profiles (virotypes have been reported with unknown implications on the pattern of spread, persistence and virulence. The aim of the present study was to compare virulence in a mouse subcutaneous sepsis model of representative ST131 clinical isolates belonging to 2 serotypes (O25b:H4, O16:H5 and nine virotypes and subtypes (A, B, C, D1, D2, D3, D4, D5 and E. Fourteen out of the 23 ST131 isolates tested (61% killed 90 to 100% of mice challenged, and 18 of 23 (78% at least 50%. Interestingly, different virulence patterns in association with virotypes were observed, from highly rapid lethality (death in less than 24 h to low final lethality (death at 7 days but with presence of an acute inflammation. This is the first study to assess virulence of ST131 isolates belonging to serotype O16:H5, which exhibited virotype C. In spite of their low virulence-gene score, O16:H5 isolates did not show significant differences in final lethality compared with highly virulent O25b:H4 isolates of virotypes A, B and C, but killed mice less rapidly. Significant differences were found, however, between virotypes A, B, C (final lethality ≥80% of mice challenged and virotypes D, E. Particularly unexpected was the low lethality of the newly assigned virotype E taking into account that it exhibited high virulence-gene score, and the same clonotype H30 as highly virulent O25b:H4 isolates of virotypes A, B and C. In vivo virulence diversity reported in this study would reflect the genetic variability within ST131 clonal group evidenced by molecular typing.

  16. 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

  17. An Optimized Medium for Screening of L-Asparaginase production by Escherichia coli

    Directory of Open Access Journals (Sweden)

    Younes Ghasemi

    2008-01-01

    Full Text Available Purified L-asparaginase II from Escherichia coli has been supplied and employed in the acute leukemia and other malignant neoplasms chemotherapy. L-asparaginase II gene (ansB in E. coli is under regulation and certain conditions is needed for expression of this gene. In this investigation ,the various concentrations of modified M9 medium ingredients and various carbon source were tested to optimize the medium for expression and identification of L-asparaginase in E. coli. Finally a semi-quantitative plate assay for L-asparaginase producing Escherichia coli is reported.

  18. 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.

  19. Genetic heterogeneity of Escherichia coli isolated from pasteurized milk in State of Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Karine Oltramari

    2014-04-01

    Full Text Available Food contamination caused by enteric pathogens is a major cause of diarrheal disease worldwide, resulting in high morbidity and mortality and significant economic losses. Bacteria are important agents of foodborne diseases, particularly diarrheagenic Escherichia coli. The present study assessed the genetic diversity and antimicrobial resistance of E. coli isolates from pasteurized milk processed in 21 dairies in northwestern State of Parana, Brazil. The 95 E. coli isolates were subjected to antimicrobial susceptibility testing according to the recommendations of the Clinical and Laboratory Standards Institute and assessed genotypically by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR. The highest rate of resistance was observed for cephalothin (55.78%. ERIC-PCR revealed high genetic diversity, clustering the 95 bacterial isolates into 90 different genotypic patterns. These results showed a heterogeneous population of E. coli in milk samples produced in the northwestern region of Paraná and the need for good manufacturing practices throughout the processing of pasteurized milk to reduce the risk of foodborne illnesses.

  20. Resistencia a antimicrobianos en aislamientos de Escherichia coli de origen animal Antimicrobial resistance of Escherichia coli isolated from animals

    OpenAIRE

    G. Carloni; De Pereyra, A.; Denamiel, G.; Gentilini, E.

    2011-01-01

    Se determinó el perfil de susceptibilidad a antimicrobianos de 100 aislamientos de E.coli provenientes de diversas patologías en bovinos, equinos, caninos y felinos, siguiendo metodología del Clinical and Laboratory Standards Institute y detectando la aparición de aislamientos multiresistentes. El panel de antibióticos ensayados incluyó amicacina, ampicilina/sulbactama, cefotaxima, ciprofloxacina, cloranfenicol, colistina, estreptomicina, gentamicina, nitrofurantoína, tetraciclina, trimetopri...

  1. Hygiene Sanitasi Pengolahan Makanan Dan Pemeriksaan Escherichia Coli (E.Coli) Pada Pecel Yang Dijual Di Pasar Petisah Tahun 2015

    OpenAIRE

    Lubis, Nur Hasanah

    2015-01-01

    Pecel is a fast food consist of boiled vegetables and served with peanut chili sauce as a mixture. The seller is used prepare and serve pecel with hands directy. It causes pecel have a hazard contamination by bacteria Escherichia Coli (E.coli). E.coli presence in source water or food is definitely an indication of human fecal contamination and the presence of E.coli shows a sign which is not good sanitation practices to water and food. The objective of this research is to know about hygien...

  2. The Antibiotic Susceptibility Patterns of Uropathogenic Escherichia Coli, With Special Reference to the Fluoroquinolones

    OpenAIRE

    Shariff V A, Abdul Rahaman; Shenoy M, Suchitra; Yadav, Taruna; M, Radhakrishna

    2013-01-01

    Context: The emergence of drug resistance to trimethoprim-sulfamethoxazole, the penicillins, cephalosporins, and fluoroquinolones by Uropathogenic Escherichia coli (UPEC) has limited the options for selecting the appropriate antibiotic for the treatment of urinary tract infections.

  3. SIMULTANEOUS EFFECTS OF SHAKING AND TEMPERATURE ON VEROTOXIN1 PHAGE INDUCTION FROM VEROTOXIGENIC ESCHERICHIA COLI STRAINS

    Directory of Open Access Journals (Sweden)

    H. Hosain Zadegan, M. Sattari, M. H. Zahir, A. A. Allame

    2006-01-01

    Full Text Available Induction of lambda phage carring verotoxin1 gene from a verotoxigenic strains of Escherichia coli and released verotoxin1 were studied under environmental factors of shaking and termperature. Verotoxin1 phage in Escherichia coli PA 101 and transductants was confirmed by bacteriophage detection assay. Shaking of culture media and increasing temperature until 42 ºC increased phage particles in supernatants of Escherichia coli PA 101. Our results indicate that environmental factors such as shaking movements in natural inhabitates of bacteria such as river or sewage streams and temperature rise in summer season could be factors in induce and release free verotoxin1 – producing phage particles in nature that in turn could be the source of phage spreading to other related bacteria , and responsible for increased outbreaks of food borne diseases with verotoxigenic Escherichia coli in warm monthes of year in tropical areas.

  4. Shigella toxin inhibition of binding and translation of polyuridylic acid by Escherichia coli ribosomes.

    OpenAIRE

    Olenick, J G; Wolfe, A D

    1980-01-01

    Shigella toxin inhibits polyuridylic acid-directed polymerization of phenylalanine in ribosome-enzyme systems obtained from Escherichia coli or from Shigella dysenteriae. The inhibition is the result of toxin acting on ribosomes to prevent polyuridylic acid attachment.

  5. Differential decay of Enterococci and Escherichia coli originating from two fecal pollution sources

    Science.gov (United States)

    Using in situ subtropical aquatic mesocosms, fecal source (cattle manure versus sewage) was shown to be the most important contributor to differential loss in viability of fecal indicator bacteria (FIB), specifically enterococci in freshwater and Escherichia coli in marine habita...

  6. Selection of unique Escherichia coli clones by random amplified polymorphic DNA (RAPD)

    DEFF Research Database (Denmark)

    Nielsen, Karen L; Godfrey, Paul A; Stegger, Marc;

    2014-01-01

    Identifying and characterizing clonal diversity are important when analysing fecal flora. We evaluated random amplified polymorphic DNA (RAPD) PCR, applied for selection of Escherichia coli isolates, by whole genome sequencing. RAPD was fast, and reproducible as screening method for selection...

  7. One year surveillance of antimicrobial sensitivity pattern of different antibiotics on clinical isolates of Escherichia coli with comparison of resistance against different antibiotics in four major cities in Bangladesh

    Directory of Open Access Journals (Sweden)

    Shamema Nasrin

    2013-10-01

    Full Text Available Background: The aim of study was to provide supportive implications for proper treatment of E. coli induced infections and related complications regarding antibiotic resistance. Methods: Total 600 isolates of E. coli from four major cities of Bangladesh were included in studies which were isolated from clinical diagnostic facilities in Dhaka, Chittagong, Rajshahi and Khulna. The antimicrobial sensitivity test of each E. coli isolate to 16 antimicrobial agents was carried out by the Kirby-Bauser disc diffusion method. Results: In the present investigation, the most effective antimicrobial against E. coli was found to be antibiotics of Carbapenem group; Doripenem 98.67% sensitive in Dhaka and Chittagong, 100% sensitive at Rajshahi and Khulna, Meropenem 89.33, 92.67, 95.33 and 97.33%, Imipenem 84.00, 86.00, 95.33 and 97.33 in Dhaka, Chittagong, Rajshahi and Khulna respectively. Apart from these third generation antibiotics like Cefixime 80.00% (D, 78.67% (C,78.00% (R, 82.00% (K and Ceftriaxone 78.00% (D, 76.67(C, 65.33(R, 66.67(K were shown satisfactory amount of sensitivity against E. Coli. Our research reveals that in Bangladesh commonly used conventional older, common, cheaper antibiotics used against E. coli were shown alarming rate of resistance to E. coli strains. Among them Amoxicillin, Tetracycline, Cloxacillin and Nalidixic Acid showed more than 80% resistance in most of the areas. Most widely used antibiotic Ciprofloxacin has become 39.99 to 49.99% resistant. Conclusion: These findings suggest urgent need for creating greater public awareness about antibiotic. It is also important that healthcare providers effectively communicate with their patients, to improve treatment compliance and health outcomes. [Int J Basic Clin Pharmacol 2013; 2(5.000: 607-612

  8. Prevalence and risk factor analysis of resistant Escherichia coli urinary tract infections in the emergency department.

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    Bailey AM

    2013-06-01

    Full Text Available Background: Escherichia coli (E. coli is a frequent uropathogen in urinary tract infections (UTI. Widespread resistance to sulfamethoxazole-trimethoprim (SMX-TMP and increasing resistance to fluoroquinolones amongst these isolates has been recognized. There are limited data demonstrating risk factors for resistance to both SMX-TMP and fluoroquinolones.Objectives: This study was conducted to assess for the prevalence of community resistance amongst E. coli isolates to SMX-TMP and levofloxacin in ambulatory patients discharged from the emergency department (ED.Methods: Adults presenting for evaluation and discharged from the ED with a diagnosis of an E. coli UTI were retrospectively reviewed. Utilizing demographic and clinical data the prevalence of E. coli resistance and risk factors associated with SMX-TMP- and fluoroquinolone-resistant infection were determined. Results: Among the 222 patients, the mean rates of E. coli susceptibility to levofloxacin and SMX-TMP were 82.4% and 72.5%, respectively. Significant risk factors for resistance to SMX-TMP included prior antibiotic use (p=0.04 and prior diagnosis of UTI (p= 0.01. Significant risk factors for resistance to levofloxacin included: male gender, age, presence of hypertension, diabetes, chronic respiratory disease, nursing home resident, previous antibiotic use, previous diagnosis of UTI, existence of renal or genitourinary abnormalities, and prior surgical procedures (p <0.05 for all comparisons. The number of hospital days prior to initial ED evaluation (p<0.001 was determined to be a predictive factor in hospital and ED readmission. Conclusions: These results suggest that conventional approaches to monitoring for patterns of susceptibility may be inadequate. It is imperative that practitioners develop novel approaches to identifying patients with risk factors for resistance. Identification of risk factors from this evaluation should prompt providers to scrutinize the use of these agents in

  9. High-level Multi-Resistant and Virulent Escherichia coli in Abeokuta, Nigeria.

    Science.gov (United States)

    Akinduti, Paul Akinniyi; Aboderin, Bukola W; Oloyede, Rasaq; Ogiogwa, Joseph I; Motayo, Babatunde O; Ejilude, Oluwaseun

    2016-01-01

    Multi-resistant Escherichia coli (E. coli) strains co-harboring virulence genes is a cause of high morbidity in Abeokuta, Nigeria. This study was designed to determine some virulent factors among enteropathogenic E. coli in Abeokuta, Nigeria. Approximately non-repetitive 102 isolates of E. coli were recovered from clinical samples from two health facilities in Abeokuta. Biotyping using API and antibiotic susceptibility was determined, and eae and flic genes were assayed by PCR. Antibiotic resistance relatedness was performed by DendroUPGMA. Results showed that 48.0% and 52.0 % were intestinal and extra-intestinal E. coli, ampicillin recorded 100% resistance, amoxycilli/clavulanic acid 64.7%, cotrimoxazole 57.8% and 56.8% resistance against cefotaxime, at MIC >16 ug/mL, 100%, 57.8%, and 50% have MIC50 to ampicillin, tetracycline, and ceftazidime, while 74.5% and 48.0% have MIC90 to ampicillin and ceftazidime. Significant rates of 4.9%, 7.8%, and 9.8% flic, eae, and flic/eae genes were found in intestinal isolates, while 2.9%, 2.0%, and 3.9% were found in extra-intestinal (P < 0.05). Two major clades of the resistant isolates reveal significant antibiotic relatedness among intestinal and extra-intestinal isolates, at 54% resistance similarities with very high multi-antibiotic resistance index of 1.0 (MARI). A high rate of undetected virulent E. coli pathotypes with high resistance could trigger unprecedented morbidity and mortality, mostly among children and the elderly. PMID:26263915

  10. Enterobacterial detection and Escherichia coli antimicrobial resistance in parrots seized from the illegal wildlife trade.

    Science.gov (United States)

    Hidasi, Hilari Wanderley; Hidasi Neto, José; Moraes, Dunya Mara Cardoso; Linhares, Guido Fontgallad Coelho; Jayme, Valéria de Sá; Andrade, Maria Auxiliadora

    2013-03-01

    Enteric bacteria are considered important potential pathogens in avian clinical medicine, causing either primary or opportunistic infections. The aim of this study was to evaluate the frequency of enterobacteria in the intestinal microbiota of psittacine birds and to determine the antimicrobial susceptibility of the Escherichia coli isolates cultured. Fecal samples were collected from 300 parrots captured from the illegal wildlife trade in Goiás, Brazil and were processed using conventional bacteriological procedures. A total of 508 isolates were obtained from 300 fecal samples: 172 E. coli (33.9% of isolates; 57.3% of individuals); 153 Enterobacter spp. (30.1% of isolates; 51.0% of individuals); 89 Klebsiella spp. (17.7% of isolates; 29.7% of individuals); 59 Citrobacter spp. (11.6% of isolates; 19.7% of individuals), 21 Proteus vulgaris (4.2% of isolates; 7.0% of individuals), 5 Providencia alcalifaciens (0.98% of isolates; 1.67% of individuals), 5 Serratia sp. (0.98% of isolates; 1.67% of individuals), 3 Hafnia aivei (0.59% of isolates; 1.00% of individuals), and 1 Salmonella sp. (0.20% of isolates; 0.33% of individuals). Escherichia coli isolates were subsequently tested for susceptibility to the following antibiotics: amoxicillin (70.93% of the isolates were resistant), ampicillin (75.58%), ciprofloxacin (23.25%), chloramphenicol (33.14%), doxycycline (64.53%), enrofloxacin (41.28%), tetracycline (69.19%), and sulfonamide (71.51%). Multi-resistance to three and four groups of antibiotics occurred in 40 samples (23.25%) and 4 samples (2.32%), respectively. These results demonstrate that illegally traded birds are carriers of potentially pathogenic bacteria, including E. coli strains with antimicrobial resistance. PMID:23505696

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

    OpenAIRE

    Farhad Safarpordehkordi; Emad Yahaghi; Ebrahim Khodaverdi Darian

    2014-01-01

    Background and Aim: Unfortunately, conventional antibiotic therapies which were used for cases of food poisoning caused by Escherichia coli are costly and ineffective. This study was carried out in order to detection and investigates the antibiotic resistance pattern of Escherichia coli isolated from chicken meat distributed in Isfahan province. Materials and Methods: 220 chicken meat samples were collected from shopping centers in Isfahan province. Samples were initially cultured and geno...

  12. Isolation of Shiga toxin-producing Escherichia coli from raw milk in Kermanshah, Iran

    OpenAIRE

    Pantea Mohammadi; Ramin Abiri; Mansour Rezaei; Siavosh Salmanzadeh-Ahrabi

    2013-01-01

    Background and Objectives Infectious diarrhoeal diseases are great problem throughout the world and are responsible for considerable morbidity and mortality. Shiga toxin-producing Escherichia coli (STEC) is a major cause of gastroenteritis that may be complicated by hemorrhagic colitis (HC) or the hemolytic uremic syndrome (HUS), which is the main cause of acute renal failure in children. Food-borne outbreaks associated with Shiga toxin-producing Escherichia coli have been well documented wor...

  13. BIOAKTIFITAS MINYAK ATSIRI SEREH Cymbopogon citratus DC. TERHADAP PERTUMBUHAN BAKTERI Escherichia coli DAN Staphylococcus aureus

    OpenAIRE

    Rahman, Hasriani

    2013-01-01

    Penelitian ini mengenai bioaktifitas minyak atsiri sereh Cymbopogon citratus DC. terhadap pertumbuhan bakteri Escherichia coli dan Staphylococcus aureus. Penelitian ini bertujuan untuk mengetahui bioaktifitas dan sifat antibakteri minyak atsiri sereh Cymbopogon citratus DC. terhadap pertumbuhan bakteri Escherichia coli dan Staphylococcus aureus. Pengujian daya hambat dilakukan dengan metode difusi agar menggunakan 5 variasi konsentrasi 100%, 50%, 25%, 12,5% dan 6,25% b/v pada media MHA (Mull...

  14. 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; Alwathnani, Hend A.; Rensing, Christopher

    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....

  15. Antibacterial activity of natural spices on multiple drug resistant Escherichia coli isolated from drinking water, Bangladesh

    OpenAIRE

    Rahman, Shahedur; Parvez, Anowar Khasru; Islam, Rezuanul; Khan, Mahboob Hossain

    2011-01-01

    Background Spices traditionally have been used as coloring agents, flavoring agents, preservatives, food additives and medicine in Bangladesh. The present work aimed to find out the antimicrobial activity of natural spices on multi-drug resistant Escherichia coli isolates. Methods Anti-bacterial potentials of six crude plant extracts (Allium sativum, Zingiber officinale, Allium cepa, Coriandrum sativum, Piper nigrum and Citrus aurantifolia) were tested against five Escherichia coli isolated f...

  16. Detection of Amp C genes encoding for beta-lactamases in Escherichia coli and Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    M Shanthi

    2012-01-01

    Full Text Available Purpose : Amp C beta-lactamase are Ambler class C enzymes that confer resistance to extended spectrum cephalosporins and are not inhibited by beta-lactamase inhibitors. Their detection is crucial, since the phenotypic tests are not standardised leading to ambiguity in interpretation of results. This study was done to detect the types of Amp C prevalent in Escherichia coli and Klebsiella pneumoniae by multiplex polymerase chain reaction (PCR. Materials and Methods : Seventy-seven consecutive cefoxitin resistant clinical isolates of E. coli (n = 25 and K. pneumoniae (n = 52 were included in the study. Antibiotic susceptibility testing to various classes of antibiotics was performed by disc diffusion using Clinical Laboratory Standards Institute (CLSI guidelines. Minimum inhibitory concentration (MIC to cefoxitin, imipenem and meropenem were determined by broth microdilution method. Isolates were screened for production of Extended Spectrum Beta-Lactamase (ESBL. Multiplex PCR was performed for the detection of Amp C genes after phenotypic testing (Hodge test and inhibitor based test. Results : Cefoxitin Hodge test was positive in 40 isolates which included 20 E. coli and 20 K. pneumoniae. There was zone enhancement with boronic acid in 55 isolates, of which 36 were K. pneumoniae and 19 were E. coli. Multiplex PCR detected Amp C in 11/25 E. coli and 12/52 K. pneumoniae isolates. The Amp C genes detected were CIT (Amp C origin - Citrobacter freundii, DHA (Dhahran Hospital, Saudi Arabia, ACC (Ambler class C, EBC (Amp C origin - Enterobacter cloacae groups. ESBL was co-produced in 54 isolates. Conclusions : Amp C was detected in 29.87% of the study isolates. Majority of them co-produced ESBL. The most common Amp C was the CIT family. Screen tests for cefoxitin resistance may be falsely positive due to production of carbapenamases.

  17. Antimicrobial-resistant faecal Escherichia coli in wild mammals in central Europe: multiresistant Escherichia coli producing extended-spectrum ß-lactamases in wild boars

    DEFF Research Database (Denmark)

    Literak, I.; Dolejska, Monika; Radimersky, T.;

    2010-01-01

    Aims: To determine the presence of antibiotic-resistant faecal Escherichia coli in populations of wild mammals in the Czech Republic and Slovakia. Methods and Results: Rectal swabs or faeces collected during 2006-2008 from wild mammals were spread on MacConkey agar and MacConkey agar containing 2...... mg l-1 of cefotaxime. From plates with positive growth, one isolate was recovered and identified as E. coli. Susceptibility to 12 antibiotics was tested using the disk diffusion method. Resistance genes, class 1 and 2 integrons and gene cassettes were detected in resistant isolates by polymerase...... prevalence of resistant isolates was 2% in small terrestrial mammals (rodents and insectivores, n(E. coli) = 242), 12% in wild ruminants and foxes (n(E. coli) = 42), while no resistant isolates were detected in brown bears (n(E. coli) = 16). In wild boars (Sus scrofa) (n(E. coli) = 290), the prevalence of...

  18. Safety of Probiotic Escherichia coli Strain Nissle 1917 Depends on Intestinal Microbiota and Adaptive Immunity of the Host▿

    OpenAIRE

    Gronbach, Kerstin; Eberle, Ute; Müller, Martina; Ölschläger, Tobias A.; Dobrindt, Ulrich; Leithäuser, Frank; Niess, Jan Hendrik; Döring, Gerd; Reimann, Jörg; Autenrieth, Ingo B.; Frick, Julia-Stefanie

    2010-01-01

    Probiotics are viable microorganisms that are increasingly used for treatment of a variety of diseases. Occasionally, however, probiotics may have adverse clinical effects, including septicemia. Here we examined the role of the intestinal microbiota and the adaptive immune system in preventing translocation of probiotics (e.g., Escherichia coli Nissle). We challenged C57BL/6J mice raised under germfree conditions (GF-raised C57BL/6J mice) and Rag1−/− mice raised under germfree conditions (GF-...

  19. Lactobacillus rhamnosus Strain GG Prevents Enterohemorrhagic Escherichia coli O157:H7-Induced Changes in Epithelial Barrier Function▿

    OpenAIRE

    Johnson-Henry, K. C.; Donato, K. A.; Shen-Tu, G.; Gordanpour, M.; Sherman, P M

    2008-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 intimately attaches to intestinal epithelial monolayers and produces attaching and effacing (A/E) lesions. In addition, EHEC infection causes disruptions of intercellular tight junctions, leading to clinical sequelae that include acute diarrhea, hemorrhagic colitis, and the hemolytic-uremic syndrome. Current therapy remains supportive since antibiotic therapy increases the risk of systemic complications. This study focused on the potential the...

  20. A Multiepitope Fusion Antigen Elicits Neutralizing Antibodies against Enterotoxigenic Escherichia coli and Homologous Bovine Viral Diarrhea Virus In Vitro

    OpenAIRE

    Emad A. Hashish; Zhang, Chengxian; Ruan, Xiaosai; Knudsen, David E.; Chase, Christopher C.; Richard E Isaacson; Zhou, Guoqiang; Zhang, Weiping

    2013-01-01

    Diarrhea is one of the most important bovine diseases. Enterotoxigenic Escherichia coli (ETEC) and bovine viral diarrhea virus (BVDV) are the major causes of diarrhea in calves and cattle. ETEC expressing K99 (F5) fimbriae and heat-stable type Ia (STa) toxin are the leading bacteria causing calf diarrhea, and BVDV causes diarrhea and other clinical illnesses in cattle of all ages. It is reported that maternal immunization with K99 fimbrial antigens provides passive protection to calves agains...