Survival ofEscherichia coliO157:H7 in soil and on lettuce after soil fumigation

2007 ◽  
Vol 53 (5) ◽  
pp. 623-635 ◽  
Author(s):  
A.  Mark Ibekwe ◽  
Catherine M. Grieve ◽  
Ching-Hong Yang
Keyword(s):  
Growth Chamber ◽  
Term Survival ◽  
Soil Microcosms ◽  
Long Term Survival ◽  
E Coli ◽  
Chamber Study ◽  
Plate Counts ◽  
Significant Pathway ◽  
Harsh Conditions

Long-term survival of Escherichia coli O157:H7 in soil and in the rhizosphere of many crops after fumigation is relatively unknown. One of the critical concerns with food safety is the transfer of pathogens from contaminated soil to the edible portion of the plants. Multiplex fluorogenic polymerase chain reaction was used in conjunction with plate counts to quantify the survival of E. coli O157:H7 in soil after fumigation with methyl bromide and methyl iodide in growth chamber and microcosm laboratory experiments. Plants were grown at 20 °C in growth chambers during the first experiment and soils were irrigated with water contaminated with E. coli O157:H7. For the second experiment, soil microcosms were used in the laboratory without plants and were inoculated with E. coli O157:H7 and spiked with the two fumigants. Primers and probes were designed to amplify and quantify the Shiga-like toxin 1 (stx1) and 2 (stx2) genes and the intimin (eae) gene of E. coli O157:H7. Both fumigants were effective in reducing pathogen concentrations in soil, and when fumigated soils were compared with nonfumigated soils, pathogen concentrations were significantly higher in the nonfumigated soils throughout the study. This resulted in a longer survival of the pathogen on the leaf surface especially in sandy soil than observed in fumigated soils. Therefore, application of fumigant may play some roles in reducing the transfer of E. coli O157:H7 from soil to leaf. Regression models showed that survival of the pathogen in the growth chamber study followed a linear model while that of the microcosm followed a curvilinear model, suggesting long-term survival of the pathogen in soil. Both experiments showed that E. coli O157:H7 can survive in the environment for a long period of time, even under harsh conditions, and the pathogen can survive in soil for more than 90 days. This provides a very significant pathway for pathogen recontamination in the environment.

scholarly journals Antiglycation Effects of Carnosine and Other Compounds on the Long-Term Survival of Escherichia coli

2010 ◽  
Vol 76 (24) ◽  
pp. 7925-7930 ◽  
Author(s):  
Evan D. Pepper ◽  
Michael J. Farrell ◽  
Gary Nord ◽  
Steven E. Finkel
Keyword(s):  
Escherichia Coli ◽  
Culture Medium ◽  
Term Survival ◽  
Long Term Survival ◽  
E Coli ◽  
Human Disorders ◽  
Domains Of Life ◽  
Carboxymethyl Lysine ◽  
Dose Dependent

ABSTRACT Glycation, or nonenzymatic glycosylation, is a chemical reaction between reactive carbonyl-containing compounds and biomolecules containing free amino groups. Carbonyl-containing compounds include reducing sugars such as glucose or fructose, carbohydrate-derived compounds such as methylglyoxal and glyoxal, and nonsugars such as polyunsaturated fatty acids. The latter group includes molecules such as proteins, DNA, and amino lipids. Glycation-induced damage to these biomolecules has been shown to be a contributing factor in human disorders such as Alzheimer's disease, atherosclerosis, and cataracts and in diabetic complications. Glycation also affects Escherichia coli under standard laboratory conditions, leading to a decline in bacterial population density and long-term survival. Here we have shown that as E. coli aged in batch culture, the amount of carboxymethyl lysine, an advanced glycation end product, accumulated over time and that this accumulation was affected by the addition of glucose to the culture medium. The addition of excess glucose or methylglyoxal to the culture medium resulted in a dose-dependent loss of cell viability. We have also demonstrated that glyoxylase enzyme GloA plays a role in cell survival during glycation stress. In addition, we have provided evidence that carnosine, folic acid, and aminoguanidine inhibit glycation in prokaryotes. These agents may also prove to be beneficial to eukaryotes since the chemical processes of glycation are similar in these two domains of life.

Long-term survival of microorganisms in frozen material from early Antarctic base camps at McMurdo Sound

1994 ◽  
Vol 6 (1) ◽  
pp. 67-68 ◽  
Author(s):  
D. B. Nedwell ◽  
N. J. Russell ◽  
T. Cresswell-Maynard
Keyword(s):  
Term Survival ◽  
Mcmurdo Sound ◽  
Long Term Survival ◽  
Plate Counts

Plate counts were made of bacteria surviving in materials from Shackleton's and Scott's camps from the first decade of this century. Several millions of bacteria per g of material were detected in samples of pony dung and lesser numbers in dried peas, pearl barley, chaff and straw. No coliforms had survived in the dung: apparent positives in the presumptive coliform counts proved to be sporing Bacillus spp. when tested in a confirmatory coliform test. Subsamples of the colonies growing on agar plates all proved to be either Bacillus spp. producing endospores or actinomycetes (Micromonospora spp.) with single spores along the hyphae.

Recovery from long-term stationary phase and stress survival in Escherichia coli require the l-isoaspartyl protein carboxyl methyltransferase at alkaline pH

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2151-2158 ◽  
Author(s):  
Wade M. Hicks ◽  
Matthew V. Kotlajich ◽  
Jonathan E. Visick
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Alkaline Ph ◽  
Term Survival ◽  
Long Term Survival ◽  
E Coli ◽  
Carboxyl Methyltransferase ◽  
Protein Carboxyl Methyltransferase ◽  
Stress Survival

The l-isoaspartyl protein carboxyl methyltransferase (pcm) can stimulate repair of isoaspartyl residues arising spontaneously in proteins to normal l-aspartyl residues. PCM is needed in Escherichia coli for maximal long-term survival when exposed to oxidative stress, osmotic stress, repeated heat stress or methanol. The effect of pH on a pcm mutant during long-term stationary phase was examined. PCM was not required for long-term survival of E. coli subjected to pH stress alone; however, PCM-deficient cells showed impaired resistance to paraquat and methanol only at elevated pH. The mutant also showed stress-survival phenotypes in minimal medium buffered to pH 9·0. Accumulation of isoaspartyl residues was accelerated at pH 8·0 or 9·0 in vivo, though PCM-deficient cells did not show higher levels of damage. However, the pcm mutant displayed an extended lag phase in recovering from stationary phase at pH 9·0. Protein repair by PCM thus plays a key role in long-term stress survival only at alkaline pH in E. coli, and it may function primarily to repair damage in cells that are recovering from nutrient limitation and in those cells that are able to divide during long-term stationary phase.

scholarly journals Long-Term Survival of Pathogenic and Sanitation Indicator Bacteria in Experimental Biowaste Composts

2005 ◽  
Vol 71 (10) ◽  
pp. 5779-5786 ◽  
Author(s):  
Mélanie Lemunier ◽  
Cédric Francou ◽  
Sandrine Rousseaux ◽  
Sabine Houot ◽  
Philippe Dantigny ◽  
...  
Keyword(s):  
Organic Waste ◽  
Fruits And Vegetables ◽  
Physicochemical Characteristics ◽  
Waste Recycling ◽  
Organic Fertilizers ◽  
Term Survival ◽  
Long Term Survival ◽  
E Coli ◽  
Forced Aeration

ABSTRACT For economic, agricultural, and environmental reasons, composting is frequently used for organic waste recycling. One approach to limiting the potential risk from bacterial food-borne illnesses is to ensure that soil amendments and organic fertilizers are disinfected. However, more knowledge concerning the microbiological safety of composted substrates other than sludge and manure is necessary. Experimental in-vessel biowaste composts were used to study the survival of seeded Listeria monocytogenes, Salmonella enterica subsp. enterica serotype Enteritidis, and Escherichia coli. Four organic waste mixtures, containing various proportions of paper and cardboard, fruits and vegetables, and green waste, were composted in laboratory reactors with forced aeration. The physicochemical and microbiological parameters were monitored for 12 weeks during composting. The survival of bacteria over a 3-month period at 25°C was assessed with samples collected after different experimental composting times. Strain survival was also monitored in mature sterilized composts. Nonsterile composts did not support pathogen growth, but survival of seeded pathogens was observed. Salmonella serovar Enteritidis survived in all composts, and longer survival (3 months) was observed in mature composts (8 and 12 weeks of composting). Mature biowaste composts may support long-term survival of Salmonella serovar Enteritidis during storage at room temperature. E. coli and L. monocytogenes survival was observed only in 4-week-old composts and never in older composts. Proper composting may prevent long-term survival of E. coli and L. monocytogenes. These results suggest that like composted sewage sludge or manure, domestic waste composts may support pathogen survival. Survival was not related to the physicochemical characteristics of the composts.

scholarly journals A Stable Bioluminescent Construct of Escherichia coli O157:H7 for Hazard Assessments of Long-Term Survival in the Environment

2003 ◽  
Vol 69 (6) ◽  
pp. 3359-3367 ◽  
Author(s):  
Jennifer M. Ritchie ◽  
Graeme R. Campbell ◽  
Jill Shepherd ◽  
Yvonne Beaton ◽  
Davey Jones ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Wild Type Strain ◽  
Light Emission ◽  
Quantitative Measure ◽  
Matric Potential ◽  
Term Survival ◽  
Long Term Survival ◽  
E Coli ◽  
Survival Studies

ABSTRACT A chromosomally lux-marked (Tn5 luxCDABE) strain of nontoxigenic Escherichia coli O157:H7 was constructed by transposon mutagenesis and shown to have retained the O157, H7, and intimin phenotypes. The survival characteristics of this strain in the experiments performed (soil at −5, −100, and −1,500 kPa matric potential and artificial groundwater) were indistinguishable from the wild-type strain. Evaluation of potential luminescence was found to be a rapid, cheap, and quantitative measure of viable E. coli O157:H7 Tn5 luxCDABE populations in environmental samples. In the survival studies, bioluminescence of the starved populations of E. coli O157:H7 Tn5 luxCDABE could be reactivated to the original levels of light emission, suggesting that these populations remain viable and potentially infective to humans. The attributes of the construct offer a cheap and low-risk substitute to the use of verocytotoxin-producing E. coli O157:H7 in long-term survival studies.

Human thymic epithelial cells maintain long-term survival of clonogenic myeloid and erythroid progenitor cells in vitro

2000 ◽  
Vol 111 (1) ◽  
pp. 363-370 ◽  
Author(s):  
Katsuto Takenaka ◽  
Mine Harada ◽  
Tomoaki Fujisaki ◽  
Koji Nagafuji ◽  
Shinichi Mizuno ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Progenitor Cells ◽  
Thymic Epithelial Cells ◽  
Erythroid Progenitor ◽  
Term Survival ◽  
Long Term Survival ◽  
Erythroid Progenitor Cells

Clinical outcome and long-term survival following radical esophagectomy in the elderly

2001 ◽  
Vol 120 (5) ◽  
pp. A747-A748
Author(s):  
S DRESNER ◽  
A IMMMANUEL ◽  
P LAMB ◽  
S GRIFFIN
Keyword(s):  
Clinical Outcome ◽  
The Elderly ◽  
Radical Esophagectomy ◽  
Term Survival ◽  
Long Term Survival

1103: Long-Term Survival Following Nephrectomy for Renal Cell Carcinoma: The 15 Year UCLA Experience

2006 ◽  
Vol 175 (4S) ◽  
pp. 355-355
Author(s):  
Manuel Eisenberg ◽  
John S. Lam ◽  
Rakhee H. Goel ◽  
Allan J. Pantuck ◽  
Robert A. Figlin ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Term Survival ◽  
Long Term Survival
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