scholarly journals Evaluation of Escherichia coli STb toxin in an in vitro organ culture model (IVOC) / Avaliação de toxina STb de Escherichia coli em modelo de cultura de órgãos in vitro (IVOC)

2021 ◽  
Vol 4 (3) ◽  
pp. 3347-3354
Author(s):  
Cristina Paiva De Sousa ◽  
J. Daniel Dubreuil
Keyword(s):  
Escherichia Coli ◽  
Small Intestine ◽  
Organ Culture ◽  
Morphometric Analysis ◽  
Heat Stable ◽  
Absorptive Cells ◽  
Culture Model ◽  
In Vitro Organ Culture ◽  
Culture Supernatants

ETEC pathogenesis comprises adhesion to the small intestine, colonization and enterotoxin production. STb is one of the heat-stable toxins produced by ETEC. Previous reports, using culture supernatants of STb-positive ETEC strains, indicated loss of villous absorptive cells causing mild atrophy and microscopic alterations in jejunum mucosa. These culture supernatants contained many other compounds beside STb toxin and in addition the quantity of toxin in these supernatants was not determined. Thus, this study was undertaken to evaluate the effect of pure STb toxin on piglet jejunum explants in an in vitro organ culture (IVOC) model. Tissues of piglets of 11 weeks were used and put into culture. Morphometric analysis of tissues revealed that villous epithelial area was reduced in tissues treated with pure STb after 3, 4 and 5 hours (p 0.0001) compared to untreated tissues. STb-treated tissues presented atrophic villi due to loss of villi tip. Our data shows that, in piglet jejunum explants, pure STb toxin can lead to cell modification and consequently to destruction, seen as villi atrophy. These changes result in a reduced absorptive area and could be partly responsible for the diarrhea observed in the animal following STb intoxication.

The Influence of Fluoride Exposure on Dentin Mineralization Using an in Vitro Organ Culture Model

2003 ◽  
Vol 73 (5) ◽  
pp. 470-475 ◽  
Author(s):  
R. Moseley ◽  
R. J. Waddington ◽  
A. J. Sloan ◽  
A. J. Smith ◽  
R. C. Hall ◽  
...  
Keyword(s):  
Organ Culture ◽  
Fluoride Exposure ◽  
Culture Model ◽  
Dentin Mineralization ◽  
In Vitro Organ Culture

Development of an in vitro organ culture model to study transmission of HIV-1 in the female genital tract

10.1038/74743 ◽  
2000 ◽  
Vol 6 (4) ◽  
pp. 475-479 ◽  
Author(s):  
Kelly B. Collins ◽  
Bruce K. Patterson ◽  
Gregory J. Naus ◽  
Daniel V. Landers ◽  
Phalguni Gupta
Keyword(s):  
Organ Culture ◽  
Genital Tract ◽  
Female Genital Tract ◽  
Culture Model ◽  
In Vitro Organ Culture ◽  
Hiv 1 ◽  
Female Genital

scholarly journals Adherence of enteroaggregative Escherichia coli to the ileal and colonic mucosa: an in vitro study utilizing the scanning electron microscopy

2011 ◽  
Vol 48 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Jacy Alves Braga de Andrade ◽  
Edna Freymüller ◽  
Ulysses Fagundes-Neto
Keyword(s):  
Escherichia Coli ◽  
Organ Culture ◽  
Colonic Mucosa ◽  
In Vitro Study ◽  
In Vitro Assays ◽  
Electron Microscopic ◽  
In Vitro Organ Culture ◽  
Scanning Electron

CONTEXT: Enteroaggregative Escherichia coli strains have been associated with persistent diarrhea in several developing countries. In vivo procedures with animal models, in vitro assays with cellular lines and in vitro organ culture with intestinal fragments have been utilized to study these bacteria and their pathogenicity. OBJECTIVE: The present experimental research assessed the pathogenic interactions of three enteroaggregative Escherichia coli strains, using the in vitro organ culture, in order to show the adherence to different regions of both, the ileal and the colonic mucosa and demonstrate possible mechanisms that could have the participation in the prolongation of diarrheiogenic process. METHODS: This study used intestinal fragments from terminal ileum and colon that were excised from pediatric patients undergoing intestinal surgeries and from adult patients that underwent to colonoscopic procedures. Each strain was tested with three intestinal fragments for each region. Tissue was fixed for scanning electron microscopic analysis. RESULTS: These bacteria colonized ileal and colonic mucosa in the typical stacked-brick configuration in the ileum and colon. In both regions, the strains were seen over a great amount of mucus and sometimes over the intact epithelium. In some regions, there is a probable evidence of effacement of the microvilli. It was possible to see adhered to the intestinal surface, bacteria fimbrial structures that could be responsible for the adherence process. CONCLUSION: In order to cause diarrhea, enteroaggregative Escherichia coli strains adhere to the intestinal mucosa, create a mucoid biofilm on the small bowel surface that could justify the digestive-absorptive abnormalities and consequently, prolonging the diarrhea.

scholarly journals Pathophysiology of enteroaggregative Escherichia coli infection: an experimental model utilizing transmission electron microscopy

2010 ◽  
Vol 47 (3) ◽  
pp. 306-312 ◽  
Author(s):  
Jacy Alves Braga de Andrade ◽  
Edna Freymüller ◽  
Ulysses Fagundes-Neto
Keyword(s):  
Escherichia Coli ◽  
Organ Culture ◽  
Colonic Mucosa ◽  
Intestinal Lumen ◽  
In Vitro Assays ◽  
Bacterial Invasion ◽  
Persistent Diarrhea ◽  
Transmission Electron ◽  
In Vitro Organ Culture

CONTEXT: Enteroaggregative Escherichia coli strains have been associated with persistent diarrhea in several developing countries. In vivo procedures with animal models as rat, rabbit and gnotobiotic piglets intestinal loops, in vitro assays with cellular lines like T84, Caco 2, HT29, HeLa e HEp-2 and in vitro organ culture with intestinal fragments have been applied to study these bacteria and their pathogenicity. OBJECTIVES: The present experimental research assessed the pathogenic interactions of three enteroaggregative Escherichia coli strains, using the in vitro organ culture, in order to observe and compare alterations in different regions of both, the ileal and the colonic mucosa. METHODS: This study applied intestinal fragments from terminal ileum and colon that were excised from pediatric and adult patients that underwent colonoscopic procedures. Tissue was fixed for transmission electron microscopic study. Each bacterium was tested with three intestinal fragments for each region. RESULTS: Enteroaggregative Escherichia coli strains colonized and provoked citotoxic effects in the ileal and colonic mucosa. Total or partial villi destruction, vacuolization of basal cytoplasm of the enterocytes, epithelium detachment, derangement of the structure and epithelial cell extrusion in ileal mucosa could explain the perpetuation of the diarrhea. Bacterial aggregates were seen in intestinal lumen associated with mucus and cellular debris and in the intercellular spaces of the destroyed epithelium, suggesting bacterial invasion that seemed to be secondary to the destruction of the tissue. CONCLUSIONS: Pathogenesis of persistent diarrhea should include alterations in the small bowel structures where the digestive-absorptive functions take place. In the colonic mucosa the inflammatory lesions could explain the occurrence of colitis.

scholarly journals EX VIVO MODEL OF RABBIT INTESTINAL EPITHELIUM APPLIED TO THE STUDY OF COLONIZATION BY ENTEROAGGREGATIVE ESCHERICHIA COLI

2017 ◽  
Vol 54 (2) ◽  
pp. 130-134 ◽  
Author(s):  
Ricardo Luís Lopes BRAGA ◽  
Ana Claudia Machado PEREIRA ◽  
Paula Azevedo dos SANTOS ◽  
Angela Corrêa FREITAS-ALMEIDA ◽  
Ana Cláudia de Paula ROSA
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Scanning Electron Microscopy ◽  
Organ Culture ◽  
Colonic Mucosa ◽  
Ex Vivo ◽  
Gastrointestinal Infections ◽  
In Vitro Organ Culture ◽  
Scanning Electron

ABSTRACT BACKGROUND The diarrheal syndrome is considered a serious public health problem all over the world and is considered a major cause of morbidity and mortality in developing countries. The high incidence of enteroaggregative Escherichia coli in diarrheal syndromes classified as an emerging pathogen of gastrointestinal infections. After decades of study, your pathogenesis remains uncertain and has been investigated mainly using in vitro models of adhesion in cellular lines. OBJECTIVE The present study investigated the interaction of enteroaggregative Escherichia coli strains isolated from childhood diarrhea with rabbit ileal and colonic mucosa ex vivo, using the in vitro organ culture model. METHODS The in vitro adhesion assays using cultured tissue were performed with the strains co-incubated with intestinal fragments of ileum and colon over a period of 6 hours. Each strain was tested with three intestinal fragments for each region. The fragments were analysed by scanning electron microscopy. RESULTS Through scanning electron microscopy we observed that all strains adhered to rabbit ileal and colonic mucosa, with the typical aggregative adherence pattern of “stacked bricks” on the epithelium. However, the highest degree of adherence was observed on colonic mucosa. Threadlike structures were found in greater numbers in the ileum compared to the colon. CONCLUSION These data showed that enteroaggregative Escherichia coli may have a high tropism for the human colon, which was ratified by the higher degree of adherence on the rabbit colonic mucosa. Finally, data indicated that in vitro organ culture of intestinal mucosa from rabbit may be used to elucidate the enteroaggregative Escherichia coli pathogenesis.

Sign in / Sign up

Export Citation Format

Share Document