Escherichia coli O157:H7-secreted cytotoxins are toxic to enterocytes and increase Escherichia coli O157:H7 colonization of jejunum and descending colon in cattle

2008 ◽  
Vol 88 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Danica Baines ◽  
Luke Masson ◽  
Tim McAllister
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Key Words ◽  
Potential Role ◽  
Enterohemorrhagic Escherichia Coli ◽  
Target Cells ◽  
Escherichia Coli O157 ◽  
Descending Colon ◽  
Key Words Escherichia Coli

Enterohemorrhagic Escherichia coli (EHEC) O157:H7-secreted cytotoxins are toxic to target cells and enhance colonization of intestinal tissues in disease-susceptible animals. It is unclear what role, if any, EHEC O157:H7-secreted cytotoxins play in the colonization of intestinal tissues of healthy reservoir animals. We previously reported that EHEC O157:H7 colonization sites were associated with focal hemorrhages in the jejunum and descending colon of persistent shedding cattle, suggesting a potential role for cytotoxins in EHEC O157:H7 colonization. We have used a traditional EHEC O157:H7 IVOC adherence assay and a novel lawn assay to examine the role of EHEC O157:H7-secreted cytotoxins in EHEC O157:H7 strain colonization of the jejunum and descending colon of non-persistent and persistent shedding cattle. Four EHEC O157:H7 strains that were previously reported to differentially colonize cattle produced cytotoxins that were differentially active against epithelial cells from the jejunum and descending colon. There was a relationship between EHEC O157:H7-secreted cytotoxin activity and strain adherence for epithelial cells from the jejunum and descending colon of cattle. There was also a greater susceptibility of epithelial cells from the jejunum and descending colon to EHEC O157:H7-secreted cytotoxins of persistent shedding cattle compared with non-persistent shedding cattle. Addition of the most active secreted cytotoxins from EHEC O157:H7 R318N to the IVOC adherence assays significantly increased the adhere nce of the most (R318N) and least (H4420N) virulent EHEC O157:H7 strain to intestinal tissues. The current study supports a role for EHEC O157:H7-secreted cytotoxins in enhancing EHEC O157:H7 colonization of intestinal tissues of cattle. Key words: Escherichia coli O157:H7, cattle, intestine, cytotoxins, colonization

scholarly journals A plasmid of enterohemorrhagic Escherichia coli O157:H7 is required for expression of a new fimbrial antigen and for adhesion to epithelial cells.

1987 ◽  
Vol 55 (2) ◽  
pp. 455-461 ◽  
Author(s):  
H Karch ◽  
J Heesemann ◽  
R Laufs ◽  
A D O'Brien ◽  
C O Tacket ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Enterohemorrhagic Escherichia Coli ◽  
Escherichia Coli O157

The effect of fasting and diet on fecal shedding of Escherichia coli O157:H7 by cattle

2000 ◽  
Vol 80 (4) ◽  
pp. 741-744 ◽  
Author(s):  
S. J. Buchko ◽  
R. A. Holley ◽  
W. O. Olson ◽  
V. P. J. Gannon ◽  
D. M. Veira
Keyword(s):  
Escherichia Coli ◽  
Key Words ◽  
Escherichia Coli O157 ◽  
Fecal Shedding ◽  
E Coli ◽  
Feed Withdrawal ◽  
Alfalfa Silage ◽  
Key Words Escherichia Coli

Cattle naturally infected with Escherichia coli O157:H7 were used to assess the effects of diet and feed withdrawal on the fecal shedding of E. coli O157:H7. Animals were fed an 80% concentrate diet (80% barley and 20% alfalfa silage), fasted for 48 h, fed a 100% forage diet (alfalfa silage), fasted for 48 h, and subsequently re-fed 100% forage (alfalfa silage). There were no differences in the numbers of animals positive for the shedding of E. coli O157:H7 when fed an 80% barley diet or an all-forage diet (P > 0.05) or during the fasting periods following each diet (P > 0.05). Upon re-feeding an all-forage diet following a 48-h fast, animals positive for E. coli O157:H7 shedding increased (P < 0.05), with 42.5% of the animals shedding the pathogen after 5 d. Re-feeding 100% forage following fasting appeared to have increased the number of animals shedding E. coli O157:H7 in their feces, which may have been influenced by diet in addition to fasting. Key words: Escherichia coli O157:H7, fasting, diet, cattle, fecal shedding

Stx2 from enterohemorrhagic Escherichia coli O157:H7 promotes colonization in the intestine of cattle

2008 ◽  
Vol 88 (4) ◽  
pp. 581-584 ◽  
Author(s):  
Danica Baines ◽  
Stephanie Erb ◽  
Tim McAllister
Keyword(s):  
Escherichia Coli ◽  
Key Words ◽  
Virulence Factor ◽  
Human Disease ◽  
Disease Outbreaks ◽  
Mucosal Damage ◽  
Enterohemorrhagic Escherichia Coli ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Colonization Process

Cattle act as the main reservoir for enterohemorrhagic Escherichia coli O157:H7, a bacterium that causes serious human disease outbreaks. It is currently not clear which bacterial or animal factors contribute to E. coli O157:H7 colonization in cattle. We recently identified mucosal hemorrhages in the jejunum, ileum and colon of persistent shedding cattle that were associated with E. coli O157:H7 colonization. This suggested that E. coli O157:H7-secreted cytotoxins may be involved in the E. coli O157:H7 colonization process. Further studies confirmed that E. coli O157:H7-secreted cytotoxins were toxic to cattle enterocytes and enhanced E. coli O157:H7 colonization of intestinal tissues. The current study examined the contribution of Stx2 to the earlier reported E. coli O157:H7- associated mucosal damage and secreted cytotoxin activity. Stx2 was not cytotoxic to enterocytes, but did enhance E. coli O157:H7 adherence to intestinal tissues in cattle. This is the first report of an E. coli O157:H7 virulence factor that can directly influence the E. coli O157:H7 colonization process in cattle. Key words: Stx2, Escherichia coli O157:H7, cattle, intestine, colonization

scholarly journals Role of ZnuABC and ZinT in Escherichia coli O157:H7 zinc acquisition and interaction with epithelial cells

2011 ◽  
Vol 11 (1) ◽  
pp. 36 ◽  
Author(s):  
Roberta Gabbianelli ◽  
Raffaella Scotti ◽  
Serena Ammendola ◽  
Patrizia Petrarca ◽  
Laura Nicolini ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Escherichia Coli O157

A rapid, sensitive method for testing the activity of Escherichia coli 0157:H7 secreted cytotoxins against epithelial cells from the jejunum and descending colon of cattle

2008 ◽  
Vol 88 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Danica Baines ◽  
Luke Masson ◽  
Tim McAllister
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Cell Lines ◽  
Escherichia Coli O157 ◽  
Enzyme Release ◽  
Human Cell Lines ◽  
E Coli ◽  
Descending Colon ◽  
Sensitive Method ◽  
Key Words Escherichia Coli

Current methods for assessing Escherichia coli O157:H7 secreted cytotoxin activity are based on exposing human cell lines for 12 to 72 h and monitoring changes in cell morphology, adherence or enzyme release. These methods, although sensitive, use non-ruminant cell lines that may not represent cattle responses to E. coli O157:H7 secreted cytotoxins. The modified lawn assay used in this study was found to be a simple, fast and sensitive method for assessing cattle epithelial cell susceptibility to E. coli O157:H 7 secreted cytotoxins within 4 to 6 h. Key words: Escherichia coli O157:H7, cattle, intestine, cytotoxins, cytotoxicity

Detection of Viable Enterohemorrhagic Escherichia coli O157 Using the Combination of Immunomagnetic Separation with the Reverse Transcription Multiplex TaqMan PCR System in Food and Stool Samples

2006 ◽  
Vol 69 (10) ◽  
pp. 2320-2328 ◽  
Author(s):  
TSUNG-YU TSAI ◽  
WAN-JU LEE ◽  
YU-JU HUANG ◽  
KUANG-LO CHEN ◽  
TZU-MING PAN
Keyword(s):  
Escherichia Coli ◽  
Reverse Transcription ◽  
Immunomagnetic Separation ◽  
The United States ◽  
Enterohemorrhagic Escherichia Coli ◽  
Target Cells ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Taqman Pcr ◽  
Stool Samples

Enterohemorrhagic Escherichia coli O157:H7 is an infectious pathogen and outbreaks have been reported all over the world, specifically in Australia, Canada, Japan, the United States, and in various countries in Europe and South Africa. Therefore, it is necessary to develop rapid methods to determine the target pathogens for food sanitation and disease. Three combinations of primers and probes were designed to detect and identify E. coli O157 using the TaqMan detection system which focuses on the specific genes eae, rfbO157, and stxII. Reverse transcription (RT) multiplex TaqMan PCR was carried out to accurately detect viable target cells correctly. Furthermore, the acidic pretreatment and immunomagnetic separation (IMS) of food and stool samples also improved the specificity and accuracy of the RT multiplex TaqMan PCR. The developed multiplex TaqMan PCR was effective in differentiating E. coli O157, enterovirulent E. coli, and non–E. coli pathogens from 100 strains which were isolated from clinical patients and the environment. Viable and nonviable cells were also distinguished by this assay. The pretreatment protocol, which included IMS to concentrate and purify the E. coli O157, was developed and the sensitivity of the assay was improved to 100 CFU/ml in pure culture, food, and stool samples. The TaqMan PCR assay is a rapid test for the detection of E. coli O157 in food and stool matrices. It shortens the process time and increases the specificity of the pathogens detected. This is critical for improving the safety and sanitation of our food supply.

scholarly journals Role of a 60-megadalton plasmid and Shiga-like toxins in the pathogenesis of infection caused by enterohemorrhagic Escherichia coli O157:H7 in gnotobiotic piglets.

1987 ◽  
Vol 55 (12) ◽  
pp. 3117-3125 ◽  
Author(s):  
S Tzipori ◽  
H Karch ◽  
K I Wachsmuth ◽  
R M Robins-Browne ◽  
A D O'Brien ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enterohemorrhagic Escherichia Coli ◽  
Escherichia Coli O157 ◽  
Gnotobiotic Piglets
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