Characterization of Escherichia coli isolated from stools and mucosa of inflammatory bowel diseases patients

• Grant number: 13/04475-3
• Support type: Regular Research Grants
• Duration: June 01, 2013 - May 31, 2016
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal researcher: Josias Rodrigues
• Grantee: Josias Rodrigues
• Home Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Inflammatory bowel diseases (IBD) are manifested as mucosal lesions along the intestinal tract, with symptoms ranging from a simple discomfort to serious alterations affecting the organ's function. Two main IBD clinical variants are known: ulcerative colitis (UC) and Crohn's disease (CD), which are distinguished by several particular features, including the extent of intestinal commitment: While UC is restricted to the colon and rectum, CD may occur along the entire length of the gut, although more frequently in the terminal ileum. IBD symptoms are a result of exacerbated immune responses linked to genetically determined immune system dysfunctions. Manifestations of the symptoms depend on environmental factors, including the intestinal microbiota, which exerts a central role in the etiopathogenesis of IBD, by triggering and sustaining the inflammatory reactions which underlie the chronic condition of the disease. Intestinal microbiota of IBD patients presents with dysbiosis, wherein an increase in the number of Escherichia coli of at least one log10 unit is observed. Data from our laboratory suggest that this bacterial elevation take place on mucosal sites only, and that these bacteria attach to Hep-2 cells with the characteristic aggregative adherence pattern and do not bear virulence factors of diarrheagenic strains. Based on these previous observations, we intend with this project to gather additional information on these bacteria, regarding both qualitative as quantitative aspects. The qualitative analysis comprises bacterial typing by MLST and classification of the strains in one of the four EcoR groups. The quantitative analysis will be carried out by submitting PCR amplicons of the 16S rDNA V6 region to temperature gradient gel electrophoresis. The DNA template for the PCRs will be purified from stools and MacConkey broth cultures of distinct clinical samples from 10 CD, 6 RU and 8 control patients. For the qualitative analysis (bacterial typing and screening for virulence factors), a collection of 430 E. coli strains isolated from 21 DC, 38 RU and 34 control patients will be used. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE CARVALHO, VANESSA RAFAELA; KELLER, ROGERIA; DA SILVA SANTOS, ANA CAROLINA; RODRIGUES, JOSIAS. Temperature Gradient Gel Electrophoresis as a Valuable Accessory Tool for Assessment of Dysbiosis in Crohn's Disease. ADVANCES IN MICROBIOLOGY, v. 6, n. 8, p. 549-554, JUL 2016. Web of Science Citations: 1.

DA SILVA SANTOS, ANA CAROLINA; RODRIGUES, JOSIAS. Draft Genome Sequence of Shiga Toxin-Producing Escherichia coli Strain D92/09. MICROBIOLOGY RESOURCE ANNOUNCEMENTS, v. 3, n. 4 JUL-AUG 2015. Web of Science Citations: 0.

DA SILVA SANTOS, ANA CAROLINA; ROMEIRO, FERNANDO GOMES; SASSAKI, LIGIA YUKIE; RODRIGUES, JOSIAS. Escherichia coli from Crohn's disease patient displays virulence features of enteroinvasive (EIEC), enterohemorragic (EHEC), and enteroaggregative (EAEC) pathotypes. GUT PATHOGENS, v. 7, JAN 29 2015. Web of Science Citations: 7.