scholarly journals Isolation, identification and antibiogram of verotoxin producing Escherichia coli from raw salad vegetables at Jashore, Bangladesh

2021 ◽  
Vol 15 (7) ◽  
pp. 401-407
Author(s):  
Sultana Meghla Nigar ◽  
Mridha Debashish ◽  
Sohel Rana Md. ◽  
Ahosanul Haque Shahid Md. ◽  
Muket Mahmud Md.
Keyword(s):  
Escherichia Coli ◽  
Salad Vegetables

scholarly journals In-vivo Effect of Probiotics on Escherichia coli O157:H7 Isolated from Salad Vegetables

2012 ◽  
Vol 1 (4) ◽  
pp. 27 ◽  
Author(s):  
Roseline Ekiomado Uzeh ◽  
Chinwe Amaka Okolo ◽  
Bamidele Abiodun Iwalokun
Keyword(s):  
Escherichia Coli ◽  
Body Weight ◽  
Good Health ◽  
Lymphoid Hyperplasia ◽  
Green Beans ◽  
Street Vendors ◽  
Green Pepper ◽  
E Coli ◽  
Salad Vegetables

<p>This study was undertaken to isolate <em>Escherichia coli </em>O157:H7 from salad vegetables, determine its pathogenicity and effect on the gastrointestinal tract of mice and sensitivity to probiotics; <em>Lactobacillus lactis </em>ATCC12315 and <em>Lactobacillus acidophilus </em>ATCC4356 in-vivo. Twenty seven samples made up of eight different types of salad vegetables which includes carrot, cabbage, cucumber, lettuce, peas, green pepper, green beans and spring onions were collected from different locations; markets, farm and street vendors in Lagos, Nigeria. Sampling was done between 13<sup>th</sup> October 2009 and 17<sup>th</sup> March 2010. In all experiments with mice the protocol for care of animal was carried out according to National Institute of Health (NIH). The mice given only <em>E. coli </em>O157:H7 developed diarrhea which led to loss of body weight and death of majority of them. On the other hand mice that were not given any microbial suspension (control), those given only probiotics, combination of <em>E. coli</em> O157:H7 and probiotics showed no symptom of diarrhea and there was increase in their body weight. The histopathology of the intestines of this group of mice showed that their intestines were not damaged, while those given only <em>E. coli</em> O157:H7 showed lymphoid hyperplasia, mucosal sloughing and inflammation (enteritis). The maintenance of good health by probiotics has again been re-emphasized.</p>

scholarly journals Prevalence of pathogenic bacteria in common salad vegetables of Dhaka Metropolis

2013 ◽  
Vol 41 (2) ◽  
pp. 159-162 ◽  
Author(s):  
Farjana Rahman ◽  
Rashed Noor
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Bacterial Pathogens ◽  
Fecal Coliforms ◽  
Microbial Quality ◽  
Vbnc Bacteria ◽  
Salad Vegetables

Microbial quality of common salad vegetables (viz. carrot, cucumber, tomato and lettuce) collected from Dhaka metropolis was analysed to detect the presence of bacterial pathogens. The occurrence of huge numbers of fecal coliforms (1.0×104 - 4.09×106 cfu/g), Escherichia coli (1.0×104 - 5.0×108 cfu/g), Staphylococcus aureus (2.0×105 - 5.95×107 cfu/g), and Listeria spp. (1.5×106 - 6.5×107 cfu/g) were detected in all the tested samples. Interestingly, occurrence of viable but non-culturable (VBNC) bacteria was also noticed. DOI: http://dx.doi.org/10.3329/bjb.v41i2.13442 Bangladesh J. Bot. 41(2): 159-162, 2012 (December)

scholarly journals Effect of Storage Temperature on the Behaviour of Escherichia coli O157:H7 and Salmonella enterica Serotype Typhimurium on Salad Vegetables

2014 ◽  
Vol 3 (2) ◽  
pp. 1 ◽  
Author(s):  
Eleni Likotrafiti ◽  
Marios Anagnou ◽  
Panagiota Lampiri ◽  
Jonathan Rhoades
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Storage Temperature ◽  
Food Poisoning ◽  
Short Exposure ◽  
Plate Count ◽  
E Coli ◽  
Fresh Vegetables ◽  
Salad Vegetables ◽  
Storage Temperatures

<p>The behaviour of <em>Escherichia coli</em> O157:H7 and <em>Salmonella </em>Typhimurium on fresh lettuce (<em>Lactuca sativa</em>), cucumber (<em>Cucumis sativus</em>) epidermis and parsley (<em>Petroselinum sativum</em>) under different storage temperatures was studied. Inoculated vegetable pieces were stored at 10 °C, 20 °C and 30 °C and <em>E. coli</em> O157:H7 and <em>S. </em>Typhimurium<em> </em>were enumerated by plate count.</p> <p>At 10 °C, both <em>E. coli</em> O157:H7 and <em>S.</em> Typhimurium declined slowly on all three vegetables whereas at higher temperatures the behaviour was markedly different. On parsley and lettuce at 20 °C <em>S.</em> Typhimurium population returned to roughly the starting count at the end of the experiment whereas it increased in cucumber. Growth of up to 0.9 log cfu/g was observed on parsley for<em> E. coli</em> O157:H7, but population changes on the other vegetables were negligible at 20 °C. At 30 °C growth was observed on all three vegetables for both <em>E. coli</em> O157:H7 and <em>S.</em> Typhimurium.</p> <p>Growth of<em> E. coli</em> O157:H7 and <em>S. </em>Typhimurium increase the risk to the consumer of some types of fresh vegetable. Storage temperature abuse of the above fresh vegetables can lead to food poisoning if not decontaminated appropriately or via cross contamination. This study shows that food safety of fresh produce is improved via storage in chilled temperatures. Even relatively short exposure (a few hours) at higher temperatures can allow growth to occur in all three vegetables thereby increasing the risk to food safety. Chilling fresh vegetables as soon as possible after harvest could prevent growth of pathogens if vegetables are cross-contaminated.</p>

Effect of Temperature and Sanitizers on the Survival of Feline Calicivirus, Escherichia coli, and F-Specific Coliphage MS2 on Leafy Salad Vegetables

2004 ◽  
Vol 67 (7) ◽  
pp. 1451-1456 ◽  
Author(s):  
PAUL B. ALLWOOD ◽  
YASHPAL S. MALIK ◽  
CRAIG W. HEDBERG ◽  
SAGAR M. GOYAL
Keyword(s):  
Escherichia Coli ◽  
Sodium Bicarbonate ◽  
Effect Of Temperature ◽  
Feline Calicivirus ◽  
E Coli ◽  
Test Organisms ◽  
Series Of Experiments ◽  
Salad Vegetables ◽  
Time To Detection ◽  
Chlorine Bleach

We conducted a series of experiments to compare the survival of Escherichia coli, feline calicivirus, and F-specific coliphage MS2 on lettuce and cabbage with and without disinfection. Inoculated produce was held at 4, 25, or 37°C for 21 days or was treated with different concentrations of sodium bicarbonate, chlorine bleach, peroxyacetic acid, or hydrogen peroxide. Survival was measured by the decimal reduction value (time to 90% reduction in titer) and the change in log titers of the test organisms. A stronger correlation of survival measures was observed between feline calicivirus and MS2 than between E. coli and either of the viral agents at 25 and 37°C. The maximum time to detection limit for MS2 at all temperatures was 9 days, whereas feline calicivirus was detected for a maximum of 14 days at 4°C. In contrast, E. coli was detectable for 21 days at 4 and 25°C and for 14 days at 37°C. Significant increases in E. coli titer occurred within the first 5 days, but virus titers decreased steadily throughout the experiments. E. coli was also highly susceptible to all disinfectants except 1% sodium bicarbonate and 50 ppm chlorine bleach, whereas the viruses were resistant to all four disinfectants.

scholarly journals Slugs: Potential Novel Vectors of Escherichia coli O157

2006 ◽  
Vol 72 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Emma L. Sproston ◽  
M. Macrae ◽  
Iain D. Ogden ◽  
Michael J. Wilson ◽  
Norval J. C. Strachan
Keyword(s):  
Escherichia Coli ◽  
Tandem Repeats ◽  
Variable Number ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Sheep Farm ◽  
Viable Bacteria ◽  
Salad Vegetables ◽  
Variable Number Tandem Repeats ◽  
Animal Feces

ABSTRACT Field and laboratory studies were performed to determine whether slugs could act as novel vectors for pathogen (e.g., Escherichia coli O157) transfer from animal feces to salad vegetables. Escherichia coli O157 was isolated from 0.21% of field slugs from an Aberdeenshire sheep farm. These isolates carried the verocytotoxin genes (vt1 and vt2) and the attaching and effacing gene (eae), suggesting that they are potentially pathogenic to humans. Strain typing using multilocus variable number tandem repeats analysis showed that slug and sheep isolates were indistinguishable. Laboratory experiments using an E. coli mutant resistant to nalidixic acid showed that the ubiquitous slug species Deroceras reticulatum could carry viable E. coli on its external surface for up to 14 days. Slugs that had been fed E. coli shed viable bacteria in their feces with numbers showing a short but statistically significant linear log decline. Further, it was found that E. coli persisted for up to 3 weeks in excreted slug feces, and hence, we conclude that slugs have the potential to act as novel vectors of E. coli O157.

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

Sites of Adsorption of the Bacteriophages T3 and T5 on the Wall of Escherichia Coli B.

1967 ◽  
Vol 25 ◽  
pp. 96-97
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Electron Microscope ◽  
Uranyl Acetate ◽  
E Coli ◽  
Receptor Sites ◽  
Rigid Cell Wall ◽  
Host Cell Surface ◽  
Bacterial Viruses ◽  
Escherichia Coli B

Bacterial viruses adsorb specifically to receptors on the host cell surface. Although the chemical composition of some of the cell wall receptors for bacteriophages of the T-series has been described and the number of receptor sites has been estimated to be 150 to 300 per E. coli cell, the localization of the sites on the bacterial wall has been unknown.When logarithmically growing cells of E. coli are transferred into a medium containing 20% sucrose, the cells plasmolize: the protoplast shrinks and becomes separated from the somewhat rigid cell wall. When these cells are fixed in 8% Formaldehyde, post-fixed in OsO4/uranyl acetate, embedded in Vestopal W, then cut in an ultramicrotome and observed with the electron microscope, the separation of protoplast and wall becomes clearly visible, (Fig. 1, 2). At a number of locations however, the protoplasmic membrane adheres to the wall even under the considerable pull of the shrinking protoplast. Thus numerous connecting bridges are maintained between protoplast and cell wall. Estimations of the total number of such wall/membrane associations yield a number of about 300 per cell.

Infection of Escherichia coli with bacteriophages

1969 ◽  
Vol 27 ◽  
pp. 370-371
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Cell Surface ◽  
Virus Type ◽  
Infection Process ◽  
Adsorption Site ◽  
The Other ◽  
Specific Receptors ◽  
Bacterial Receptors

The first step in the infection of a bacterium by a virus consists of a collision between cell and bacteriophage. The presence of virus-specific receptors on the cell surface will trigger a number of events leading eventually to release of the phage nucleic acid. The execution of the various "steps" in the infection process varies from one virus-type to the other, depending on the anatomy of the virus. Small viruses like ØX 174 and MS2 adsorb directly with their capsid to the bacterial receptors, while other phages possess attachment organelles of varying complexity. In bacteriophages T3 (Fig. 1) and T7 the small conical processes of their heads point toward the adsorption site; a welldefined baseplate is attached to the head of P22; heads without baseplates are not infective.

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