Enteroaggregative Escherichia coli (EAEC) is an increasingly recognized pathogen of human diarrhea. This organism has been implicated in sporadic diarrhea in developing and industrialized countries, in the persistent diarrhea syndrome in AIDS patients and children in the developing world, in traveler's diarrhea, and in various diarrheal outbreaks. The PI discovered this pathotype of diarrheagenic E. coli and has been the leader in describing the pathogenesis and epidemiology of this organism, This is a competing continuation of our fundamental work on the pathogenesis of EAEC infection. Overall, our objectives are to advance knowledge of EAEC pathogenesis, to better define true EAEC pathogens, to refine diagnostic methods and to identify protective immunogen. The three aims of this proposal seek to extend the most important and promising aspects of the work funded under the current award.
Aim 1 : Characterization of EAEC adhesion-Aggregation is the defining characterization of EAEC. Our observations suggest that aggregative adherence (AA) is a prelude to biofilm formation, which occurs in vivo and which can be modeled in vitro. In this aim, we will further elucidate fundamental aspects of EAEC adherence.
Aim 2 : The Regulation of EAEC virulence- AggR is a highly prevalent and conserved activator of AAF expression. However, nothing else is known of the regulation of EAEC virulence. Beginning with AggR, we will expand our studies of EAEC gene regulation.
Aim 3 : Reconstructing EAEC-We will use in vitro organ culture and T84 cell models of EAEC infection to answer the question: what genes are necessary and sufficient to confer the effects that we observe? The work under this award will greatly advance the current state of knowledge of EAEC and will result in the identification of pathogenetic mechanisms, of diagnostic reagents and in vaccine candidates.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI033096-11
Application #
6373289
Study Section
Special Emphasis Panel (ZRG1-MBC-1 (01))
Program Officer
Grave, Gilman D
Project Start
2000-08-01
Project End
2005-07-31
Budget Start
2001-08-01
Budget End
2002-07-31
Support Year
11
Fiscal Year
2001
Total Cost
$374,275
Indirect Cost
Name
University of Maryland Baltimore
Department
Pediatrics
Type
Schools of Medicine
DUNS #
003255213
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Boll, Erik J; Ayala-Lujan, Jorge; Szabady, Rose L et al. (2017) Enteroaggregative Escherichia coli Adherence Fimbriae Drive Inflammatory Cell Recruitment via Interactions with Epithelial MUC1. MBio 8:
DeBoer, Mark D; Vijayakumar, Vidhya; Gong, Meiqing et al. (2017) Mice with infectious colitis exhibit linear growth failure and subsequent catch-up growth related to systemic inflammation and IGF-1. Nutr Res 39:34-42
Santiago, Araceli E; Yan, Michael B; Tran, Minh et al. (2016) A large family of anti-activators accompanying XylS/AraC family regulatory proteins. Mol Microbiol 101:314-32
Boisen, Nadia; Melton-Celsa, Angela R; Scheutz, Flemming et al. (2015) Shiga toxin 2a and Enteroaggregative Escherichia coli--a deadly combination. Gut Microbes 6:272-8
Vijayakumar, Vidhya; Santiago, Araceli; Smith, Rachel et al. (2014) Role of class 1 serine protease autotransporter in the pathogenesis of Citrobacter rodentium colitis. Infect Immun 82:2626-36
Izquierdo, Mariana; Alvestegui, Alejandra; Nataro, James P et al. (2014) Participation of integrin ?5?1 in the fibronectin-mediated adherence of enteroaggregative Escherichia coli to intestinal cells. Biomed Res Int 2014:781246
Ruiz-Perez, Fernando; Nataro, James P (2014) Bacterial serine proteases secreted by the autotransporter pathway: classification, specificity, and role in virulence. Cell Mol Life Sci 71:745-70
Berry, Andrea A; Yang, Yi; Pakharukova, Natalia et al. (2014) Structural insight into host recognition by aggregative adherence fimbriae of enteroaggregative Escherichia coli. PLoS Pathog 10:e1004404
Izquierdo, Mariana; Navarro-Garcia, Fernando; Nava-Acosta, Raul et al. (2014) Identification of cell surface-exposed proteins involved in the fimbria-mediated adherence of enteroaggregative Escherichia coli to intestinal cells. Infect Immun 82:1719-24
Boisen, Nadia; Hansen, Anne-Marie; Melton-Celsa, Angela R et al. (2014) The presence of the pAA plasmid in the German O104:H4 Shiga toxin type 2a (Stx2a)-producing enteroaggregative Escherichia coli strain promotes the translocation of Stx2a across an epithelial cell monolayer. J Infect Dis 210:1909-19

Showing the most recent 10 out of 31 publications