scholarly journals Survival of Escherichia coli O157:H7 in Soils from Vegetable Fields with Different Cultivation Patterns

2013 ◽  
Vol 79 (5) ◽  
pp. 1755-1756 ◽  
Author(s):  
Zhiyuan Yao ◽  
Gang Wei ◽  
Haizhen Wang ◽  
Laosheng Wu ◽  
Jianjun Wu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Organic Carbon ◽  
Open Field ◽  
Soil Ph ◽  
Phospholipid Fatty Acids ◽  
Escherichia Coli O157 ◽  
Field Soil ◽  
Content Type ◽  
Greenhouse Cultivation

ABSTRACTEscherichia coliO157:H7 survived longer in soils from plastic-greenhouse cultivation than soils from the open field. Soil pH, organic carbon levels, and the ratio of bacterial phospholipid fatty acids (PLFAs) to fungal PLFAs played the significant roles in survival of O157:H7. Greater attention should be paid to the control of pathogen contamination under conditions of plastic-greenhouse cultivation.

scholarly journals Complete Genome Sequence of Escherichia coli O157:H7 Phage PhiG17

2019 ◽  
Vol 8 (3) ◽  
Author(s):  
Muyiwa A. Akindolire ◽  
Bukola R. Aremu ◽  
Collins N. Ateba
Keyword(s):  
Escherichia Coli ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Whole Genome Sequence ◽  
Escherichia Coli O157 ◽  
Content Type ◽  
North West ◽  
The North ◽  
Genetic Features

Here, we announce the complete genome sequence of bacteriophage PhiG17, which is virulent to Escherichia coli O157:H7 strains and was isolated from cattle feces in the North West province of South Africa. This report presents the major genetic features of the phage PhiG17 based on its whole-genome sequence.

scholarly journals Fecal Metagenome Sequences from Lactating Dairy Cows Shedding Escherichia coli O157:H7

2018 ◽  
Vol 7 (18) ◽  
Author(s):  
Serajus Salaheen ◽  
Seon Woo Kim ◽  
Jeffrey S. Karns ◽  
Bradd J. Haley ◽  
Jo Ann S. Van Kessel
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Causative Agent ◽  
Public Domain ◽  
Escherichia Coli O157 ◽  
Content Type ◽  
The Public ◽  
E Coli ◽  
Lactating Dairy Cows ◽  
Human Infections

Cattle are primary reservoirs of Escherichia coli O157:H7, a causative agent of severe human infections. To facilitate analyses of the communities in which this pathogen is found, we sequenced the fecal metagenomes of 10 dairy cows shedding E. coli O157:H7 and added them to the public domain.

scholarly journals Application of AlkBGT and AlkL from Pseudomonas putida GPo1 for Selective Alkyl Ester ω-Oxyfunctionalization in Escherichia coli

2016 ◽  
Vol 82 (13) ◽  
pp. 3801-3807 ◽  
Author(s):  
Youri M. van Nuland ◽  
Gerrit Eggink ◽  
Ruud A. Weusthuis
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Esters ◽  
Reaction Conditions ◽  
Oxidation Activity ◽  
Content Type ◽  
Whole Cells ◽  
Butyl Esters ◽  
Acid Esters

ABSTRACTThe enzyme system AlkBGT fromPseudomonas putidaGPo1 can efficiently ω-functionalize fatty acid methyl esters. Outer membrane protein AlkL boosts this ω-functionalization. In this report, it is shown that whole cells ofEscherichia coliexpressing the AlkBGT system can also ω-oxidize ethyl nonanoate (NAEE). Coexpression of AlkBGT and AlkL resulted in 1.7-fold-higher ω-oxidation activity on NAEE. With this strain, initial activity on NAEE was 70 U/g (dry weight) of cells (gcdw), 67% of the initial activity on methyl nonanoate. In time-lapse conversions with 5 mM NAEE the main product was 9-hydroxy NAEE (3.6 mM), but also 9-oxo NAEE (0.1 mM) and 9-carboxy NAEE (0.6 mM) were formed. AlkBGT also ω-oxidized ethyl, propyl, and butyl esters of fatty acids ranging from C6to C10. Increasing the length of the alkyl chain improved the ω-oxidation activity of AlkBGT on esters of C6and C7fatty acids. From these esters, application of butyl hexanoate resulted in the highest ω-oxidation activity, 82 U/gcdw. Coexpression of AlkL only had a positive effect on ω-functionalization of substrates with a total length of C11or longer. These findings indicate that AlkBGT(L) can be applied as a biocatalyst for ω-functionalization of ethyl, propyl, and butyl esters of medium-chain fatty acids.IMPORTANCEFatty acid esters are promising renewable starting materials for the production of ω-hydroxy fatty acid esters (ω-HFAEs). ω-HFAEs can be used to produce sustainable polymers. Chemical conversion of the fatty acid esters to ω-HFAEs is challenging, as it generates by-products and needs harsh reaction conditions. Biocatalytic production is a promising alternative. In this study, biocatalytic conversion of fatty acid esters toward ω-HFAEs was investigated using whole cells. This was achieved with recombinantEscherichia colicells that produce the AlkBGT enzymes. These enzymes can produce ω-HFAEs from a wide variety of fatty acid esters. Medium-chain-length acids (C6to C10) esterified with ethanol, propanol, or butanol were applied. This is a promising production platform for polymer building blocks that uses renewable substrates and mild reaction conditions.

scholarly journals Evaluation of Physical Coverings Used To Control Escherichia coli O157:H7 at the Compost Heap Surface

2011 ◽  
Vol 77 (14) ◽  
pp. 5044-5049 ◽  
Author(s):  
Marion W. Shepherd ◽  
Jinkyung Kim ◽  
Xiuping Jiang ◽  
Michael P. Doyle ◽  
Marilyn C. Erickson
Keyword(s):  
Escherichia Coli ◽  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Field Trials ◽  
Escherichia Coli O157 ◽  
Protection Agency ◽  
Content Type ◽  
The U.S

ABSTRACTThroughout four field trials, compost heaps covered with finished compost maintained temperatures under the physical covering that were ca. 7 to 15.5°C higher, resulting in rapidEscherichia coliO157:H7 reduction, than those of the heaps covered with fresh straw or left uncovered. Our results validated recommendations made by the U.S. Environmental Protection Agency for covering fresh compost.

scholarly journals Molecular Profiling of Escherichia coli O157:H7 and Non-O157 Strains Isolated from Humans and Cattle in Alberta, Canada

2014 ◽  
Vol 53 (3) ◽  
pp. 986-990 ◽  
Author(s):  
Linda Chui ◽  
Vincent Li ◽  
Patrick Fach ◽  
Sabine Delannoy ◽  
Katarzyna Malejczyk ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Molecular Profiling ◽  
Surveillance Program ◽  
Escherichia Coli O157 ◽  
Significant Determinant ◽  
Content Type ◽  
Virulence Markers ◽  
Almost All

Virulence markers in Shiga toxin-producingEscherichia coli(STEC) and their association with diseases remain largely unknown. This study determines the importance of 44 genetic markers for STEC (O157 and non-O157) from human clinical cases and their correlation to disease outcome. STEC isolated from a cattle surveillance program were also included. The virulence genes tested were present in almost all O157:H7 isolates but highly variable in non-O157 STEC isolates. Patient age was a significant determinant of clinical outcome.

scholarly journals Enhanced Virulence of the Escherichia coli O157:H7 Spinach-Associated Outbreak Strain in Two Animal Models Is Associated with Higher Levels of Stx2 Production after Induction with Ciprofloxacin

2014 ◽  
Vol 82 (12) ◽  
pp. 4968-4977 ◽  
Author(s):  
T. Zangari ◽  
A. R. Melton-Celsa ◽  
A. Panda ◽  
M. A. Smith ◽  
I. Tatarov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Animal Models ◽  
Shiga Toxin ◽  
Hemorrhagic Colitis ◽  
Escherichia Coli O157 ◽  
Outbreak Strain ◽  
Content Type ◽  
Intestinal Pathology ◽  
Phage Dna ◽  
Uremic Syndrome

ABSTRACTShiga toxin (Stx)-producingEscherichia coli(STEC) causes hemorrhagic colitis and the hemolytic-uremic syndrome (HUS). STEC strains may produce Stx1a and/or Stx2a or variants of either toxin. A 2006 spinach-associated outbreak of STEC O157:H7 resulted in higher hospitalization and HUS rates than previous STEC outbreaks. The spinach isolate, strain K3995, contains bothstx2aandstx2c. We hypothesized that the enhanced virulence of K3995 reflects the combination ofstx2alleles (carried on lysogenic phages) and/or the amount of Stx2 made by that strain. We compared the virulence of K3995 to those of other O157:H7 isolates and an isogenic Stx2 mutant in rabbits and mice. We also measured the relative levels of Stx2 produced from those strains with or without induction of thestx-carrying phage. Some rabbits infected with K3995 exhibited intestinal pathology and succumbed to infection, while none of those infected with O157:H7 strain 2812 (Stx1a+Stx2a+) died or showed pathological signs. Rabbits infected with the isogenic Stx2a mutant K3995stx2a::catwere not colonized as well as those infected with K3995 and exhibited no signs of disease. In the streptomycin-treated mouse model, more animals infected with K3995 died than did those infected with O157:H7 strain 86-24 (Stx2a+). Additionally, K3995 produced higher levels of total Stx2 and toxin phage DNA in cultures after phage induction than did 86-24. Our results demonstrate the greater virulence of K3995 compared to other O157:H7 strains in rabbits and mice. We conclude that this enhanced virulence is linked to higher levels of Stx2 expression as a consequence of increased phage induction.

scholarly journals Salmonella and Escherichia coli O157:H7 Survival in Soil and Translocation into Leeks (Allium porrum) as Influenced by an Arbuscular Mycorrhizal Fungus (Glomus intraradices)

2013 ◽  
Vol 79 (6) ◽  
pp. 1813-1820 ◽  
Author(s):  
Joshua B. Gurtler ◽  
David D. Douds ◽  
Brian P. Dirks ◽  
Jennifer J. Quinlan ◽  
April M. Nicholson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Glomus Intraradices ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Allium Porrum ◽  
Escherichia Coli O157 ◽  
Content Type ◽  
E Coli ◽  
The Mean

ABSTRACTA study was conducted to determine the influence of arbuscular mycorrhizal (AM) fungi onSalmonellaand enterohemorrhagicEscherichia coliO157:H7 (EHEC) in autoclaved soil and translocation into leek plants. Six-week-old leek plants (with [Myc+] or without [Myc−] AM fungi) were inoculated with composite suspensions ofSalmonellaor EHEC at ca. 8.2 log CFU/plant into soil. Soil, root, and shoot samples were analyzed for pathogens on days 1, 8, 15, and 22 postinoculation. Initial populations (day 1) were ca. 3.1 and 2.1 log CFU/root, ca. 2.0 and 1.5 log CFU/shoot, and ca. 5.5 and 5.1 CFU/g of soil forSalmonellaand EHEC, respectively. Enrichments indicated that at days 8 and 22, only 31% of root samples were positive for EHEC, versus 73% positive forSalmonella. The meanSalmonellalevel in soil was 3.4 log CFU/g at day 22, while EHEC populations dropped to ≤0.75 log CFU/g by day 15. Overall,Salmonellasurvived in a greater number of shoot, root, and soil samples, compared with the survival of EHEC. EHEC was not present in Myc− shoots after day 8 (0/16 samples positive); however, EHEC persisted in higher numbers (P= 0.05) in Myc+ shoots (4/16 positive) at days 15 and 22.Salmonella, likewise, survived in statistically higher numbers of Myc+ shoot samples (8/8) at day 8, compared with survival in Myc− shoots (i.e., only 4/8). These results suggest that AM fungi may potentially enhance the survival ofE. coliO157:H7 andSalmonellain the stems of growing leek plants.

scholarly journals Characterization of Third-Generation-Cephalosporin-Resistant Shiga Toxin-Producing Strains of Escherichia coli O157:H7 in Japan

2015 ◽  
Vol 53 (9) ◽  
pp. 3035-3038 ◽  
Author(s):  
Ryuji Kawahara ◽  
Kazuko Seto ◽  
Masumi Taguchi ◽  
Chie Nakajima ◽  
Yuko Kumeda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Generation Cephalosporin ◽  
Escherichia Coli O157 ◽  
Third Generation ◽  
Content Type ◽  
Resistant Strains ◽  
Third Generation Cephalosporins

We isolated Shiga toxin-producingEscherichia coliO157:H7 strains resistant to third-generation cephalosporins. The resistant strains harboredblaCMY-2, a plasmid-mediated AmpC β-lactamase. Genotyping of isolates revealed the possible spread of this problematic bacterium. Results suggested the importance of the investigation and surveillance of enterobacteria with plasmids harboringblaCMY-2.

scholarly journals Physical Covering for Control of Escherichia coli O157:H7 and Salmonella spp. in Static and Windrow Composting Processes

2015 ◽  
Vol 81 (6) ◽  
pp. 2063-2074 ◽  
Author(s):  
Jitendra R. Patel ◽  
Irene Yossa ◽  
Dumitru Macarisin ◽  
Patricia Millner
Keyword(s):  
Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Bacterial Reduction ◽  
Salmonella Spp ◽  
Rapid Reduction ◽  
Content Type ◽  
E Coli ◽  
Windrow Composting ◽  
Composting Systems ◽  
Feedstock Material

ABSTRACTThis study investigated the effect of a 30-cm covering of finished compost (FC) on survival ofEscherichia coliO157:H7 andSalmonellaspp. in active static and windrow composting systems. Feedstocks inoculated withE. coliO157:H7 (7.41 log CFU/g) andSalmonella(6.46 log CFU/g) were placed in biosentry tubes (7.5-cm diameter, 30-cm height) at three locations: (i and ii) two opposing sides at the interface between the FC cover layer (where present) and the feedstock material (each positioned approximately 10 cm below the pile's surface) and (iii) an internal location (top) (approximately 30 cm below the surface). On specific sampling days, surviving populations of inoculatedE. coliO157:H7 andSalmonella, genericE. coli, and coliforms in compost samples were determined.Salmonellaspp. were reduced significantly within 24 h in windrow piles and were below the detection limit after 3 and 7 days at internal locations of windrow and static piles containing FC covering, respectively. Likewise,E. coliO157:H7 was undetectable after 1 day in windrow piles covered with finished compost. Use of FC as a covering layer significantly increased the number of days that temperatures in the windrows remained ≥55°C at all locations and in static piles at internal locations. These time-temperature exposures resulted in rapid reduction of inoculated pathogens, and the rate of bacterial reduction was rapid in windrow piles. The sample location significantly influenced the survival of these pathogens at internal locations compared to that at interface locations of piles. Finished compost covering of compost piles aids in the reduction of pathogens during the composting process.

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