Factors influencing the persistence ofEscherichia coliO157:H7 lineages in feces from cattle fed grain versus grass hay diets

2010 ◽  
Vol 56 (8) ◽  
pp. 667-675 ◽  
Author(s):  
Ross M.S. Lowe ◽  
Krysty Munns ◽  
L. Brent Selinger ◽  
Linda Kremenik ◽  
Danica Baines ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Hemorrhagic Colitis ◽  
Escherichia Coli O157 ◽  
Negative Bacterium ◽  
Gram Negative ◽  
E Coli ◽  
Factors Influencing ◽  
Uremic Syndrome

Escherichia coli O157:H7 is a pathogenic, gram-negative bacterium that causes diarrhea, hemorrhagic colitis, and can lead to fatal hemolytic uremic syndrome in humans. We examined the persistence of E. coli O157:H7 lineages I and II in feces held at 4, 12, and 25 °C, from animals fed either grain or hay diets. Three strains of each lineage I and II were inoculated into grain-fed or hay-fed feces, and their persistence was monitored over 28 days. No significant differences in E. coli O157:H7 survival between the 2 lineages in both fecal types was found at the examined temperatures. Volatile fatty acids were higher in grain-fed than in hay-fed feces, resulting in consistently lower pH in the grain-fed feces at 4, 12 and 25 °C. Regardless of lineage type, E. coli O157:H7 CFUs were significantly higher in grain-fed than in hay-fed feces at 4 and 25 °C. Escherichia coli O157:H7 survival was highest in grain-fed feces at 25 °C up to 14 days. Our results indicate that the 2 lineages of E. coli O157:H7 do not differ in their persistence; however, it appears that temperature and feces type both affect the survival of the pathogen.

A Comparison of the Survival in Feces and Water of Escherichia coli O157:H7 Grown under Laboratory Conditions or Obtained from Cattle Feces

2006 ◽  
Vol 69 (1) ◽  
pp. 6-11 ◽  
Author(s):  
L. SCOTT ◽  
P. McGEE ◽  
J. J. SHERIDAN ◽  
B. EARLEY ◽  
N. LEONARD
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogen ◽  
Hemorrhagic Colitis ◽  
Contaminated Water ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Cattle Feces ◽  
Oral Inoculation ◽  
Before And After ◽  
Uremic Syndrome

Escherichia coli O157:H7 is an important foodborne pathogen that can cause hemorrhagic colitis and hemolytic uremic syndrome. Cattle feces and fecally contaminated water are important in the transmission of this organism on the farm. In this study, the survival of E. coli O157:H7 in feces and water was compared following passage through the animal digestive tract or preparation in the laboratory. Feces were collected from steers before and after oral inoculation with a marked strain of E. coli O157:H7. Fecal samples collected before cattle inoculation were subsequently inoculated with the marked strain of E. coli O157:H7 prepared in the laboratory. Subsamples were taken from both animal and laboratory-inoculated feces to inoculate 5-liter volumes of water. E. coli O157:H7 in feces survived up to 97 days, and survival was not affected by the method used to prepare the inoculating strain. E. coli O157:H7 survived up to 109 days in water, and the bacteria collected from inoculated cattle were detected up to 10 weeks longer than the laboratory-prepared culture. This study suggests that pathogen survival in low-nutrient conditions may be enhanced by passage through the gastrointestinal tract.

How Does Escherichia coli O157:H7 Testing in Meat Compare with What We Are Seeing Clinically?

2000 ◽  
Vol 63 (6) ◽  
pp. 819-821 ◽  
Author(s):  
DAVID W. K. ACHESON
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Shiga Toxin ◽  
Food Supply ◽  
The United States ◽  
Escherichia Coli O157 ◽  
Current Policy ◽  
E Coli ◽  
Different Types ◽  
Uremic Syndrome

Escherichia coli O157:H7 is but one of a group of Shiga toxin-producing E. coli (STEC) that cause both intestinal disease such as bloody and nonbloody diarrhea and serious complications like hemolytic uremic syndrome (HUS). While E. coli O157: H7 is the most renowned STEC, over 200 different types of STEC have been documented in meat and animals, at least 60 of which have been linked with human disease. A number of studies have suggested that non-O157 STEC are associated with clinical disease, and non-O157 STEC are present in the food supply. Non-O157 STEC, such as O111 have caused large outbreaks and HUS in the United States and other countries. The current policy in the United States is to examine ground beef for O157:H7 only, but restricting the focus to O157 will miss other important human STEC pathogens.

Escherichia coli O157:H7: Epidemiology, Pathogenesis, and Methods for Detection in Food

1992 ◽  
Vol 55 (7) ◽  
pp. 555-565 ◽  
Author(s):  
NISHA V. PADHYE ◽  
MICHAEL P. DOYLE
Keyword(s):  
Escherichia Coli ◽  
Care Center ◽  
Watery Diarrhea ◽  
Clinical Samples ◽  
Escherichia Coli O157 ◽  
Intestinal Epithelial ◽  
Day Care Center ◽  
E Coli ◽  
Life Threatening ◽  
Uremic Syndrome

Escherichia coli O157:H7 is now recognized as an important human pathogen. Illnesses caused by E. coli O157:H7 infection can range from self-limited, watery diarrhea to life-threatening manifestations such as hemolytic uremic syndrome or thrombotic thrombocytopenic purpura. The mode of transmission is primarily through food; however, person-to-person transmission also has been identified in some day-care center and nursing home out-breaks. Studies to date indicate that cattle are an important reservoir of the organism. Although adhesion to intestinal epithelial cells and verotoxins are considered important virulence factors in the pathogenesis of the organism, more research is are necessary to determine the exact mechanism of pathogenicity. There is need for a rapid diagnostic test for the detection of E. coli O157:H7 in food and in clinical samples. Several useful research reagents have been developed for detecting E. coli O157:H7; however, they must be applied to a procedure that is specific, sensitive, rapid, easy to use, and commercially available so that microbiological laboratories can readily use them.

Factors Influencing Attachment of Escherichia coli O157:H7 to Beef Tissues and Removal Using Selected Sanitizing Rinses‡

1996 ◽  
Vol 59 (5) ◽  
pp. 453-459 ◽  
Author(s):  
PINA M. FRATAMICO ◽  
FRANKIE J. SCHULTZ ◽  
ROBERT C. BENEDICT ◽  
ROBERT L. BUCHANAN ◽  
PETER H. COOKE
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Surface Structures ◽  
Escherichia Coli O157 ◽  
Adipose Tissues ◽  
E Coli ◽  
Factors Influencing ◽  
Significant Difference ◽  
Phosphate Buffered Saline ◽  
Scanning Electron

Attachment of E. coli O157:H7 and E. coli K12 to beef tenderloin filet, chuck, and adipose tissues was studied. Most attachment occurred within 1 min of incubation; the number of attached organisms depended on the concentration of bacteria in the liquid inoculum. Similar levels of E. coli bound to the three types of beef tissues tested. E. coli O157:H7 was heavily piliated; however, there was no significant difference between levels of bound E. coli O157:H7 and E. coli K12, indicating that these surface structures apparently are not involved in attachment. Scanning electron photomicrographs of meat tissue and of purified collagen suggested that bacteria attached primarily to collagen fibers. Rinsing solutions consisting of 10% trisodium phosphate (TSP), 2% acetic acid (HAc), phosphate-buffered saline (PBS) and combinations of each were tested for effectiveness in reducing the number of attached E. coli. The level of bacteria removed from tenderloin tissue following TSP, HAc, or PBS rinses did not differ considerably. When beef tissues were stored at 4°C for 18 h after the various rinse combinations, TSP rinse treatments reduced the levels of E. coli K12 and O157:H7 attached to adipose tissue up to 3.4 and 2.7 log units, respectively, compared to PBS rinse treatments. Therefore, TSP may be effective for reducing populations of E. coli O157:H7 on beef carcass tissue.

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 Identification and Biochemical Characterization of a Novel Protein Phosphatase 2C-Like Ser/Thr Phosphatase in Escherichia coli

2018 ◽  
Vol 200 (18) ◽  
Author(s):  
Krithika Rajagopalan ◽  
Elizabeth Nagle ◽  
Jonathan Dworkin
Keyword(s):  
Escherichia Coli ◽  
Protein Phosphatase ◽  
Biochemical Characterization ◽  
Regulatory Protein ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Novel Protein

Regulatory protein phosphorylation is a conserved mechanism of signaling in all biological systems. Recent phosphoproteomic analyses of phylogenetically diverse bacteria, including the model Gram-negative bacteriumEscherichia coli, demonstrate that many proteins are phosphorylated on serine or threonine residues. In contrast to phosphorylation on histidine or aspartate residues, phosphorylation of serine and threonine residues is stable and requires the action of a partner Ser/Thr phosphatase to remove the modification. Although a number of Ser/Thr kinases have been reported inE. coli, no partner Ser/Thr phosphatases have been identified. Here, we biochemically characterize a novel Ser/Thr phosphatase that acts to dephosphorylate a Ser/Thr kinase that is encoded in the same operon.

scholarly journals Complete Genome Sequence of Escherichia coli Podophage Penshu1

2019 ◽  
Vol 8 (38) ◽  
Author(s):  
Douglas Pechacek ◽  
Myung Hwangbo ◽  
Russell Moreland ◽  
Mei Liu ◽  
Jolene Ramsey
Keyword(s):  
Escherichia Coli ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Coliform Bacteria ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Protein Encoding ◽  
Encoding Genes

Escherichia coli 4s is a Gram-negative bacterium found in the equine intestinal ecosystem alongside diverse other coliform bacteria and bacteriophages. This announcement describes the complete genome of the T7-like E. coli 4s podophage Penshu1. From its 39,263-bp genome, 54 protein-encoding genes and a 179-bp terminal repeat were predicted.

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