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Molecular and structural characterization of ETT-2 (Escherichia coli type III secretion system 2) of enteroaggregative E. coli

Grant number: 16/50479-9
Support type:Regular Research Grants
Duration: September 01, 2017 - August 31, 2019
Field of knowledge:Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
Cooperation agreement: University of Virginia
Mobility Program: SPRINT - Projetos de pesquisa - Mobilidade
Principal Investigator:Waldir Pereira Elias Junior
Grantee:Waldir Pereira Elias Junior
Principal investigator abroad: James Paul Nataro
Institution abroad: University of Virginia (UVa), United States
Home Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
Associated research grant:15/15135-4 - Characterization of ETT2 (Escherichia coli type III secretion system 2) of enteroaggregative E. coli, AP.R


Enteroaggressive Escherichia coli (EAEC) are emerging pathogens associated with cases of diarrhea in children and adults, in both developing and developed countries. In Brazil, EAEC has been found as the most prevalent diarrhea genic E. coli path type. This path type is very heterogeneous regarding the presence of putative virulence factors, indicating a multifactorial profile to cause disease. Analysis of the genome of an EAEC prototype strain (042, stereotype 044:H18) indicated the presence of genes encoding a type 111 secretion system (T388) which, in other pathogens, is associated with the translocation of efector proteins directly into the cytoplasm of eukaryotic cells. This system, called ETT-2 (Escherichia coli type three-secretion system 2), exhibits high similarity to that found in salmonela enteric and hemorrhagic E. coli. In the genome of EAEC 042, all genes that comprise ETT-2 are intact, suggesting their functionality. Until the present moment, such activity has not been demonstrated, nor the possible transported translocators identified. Therefore, the present study has the primary objective to characterize the EAEC 042 ETT-2 system, in terms of identification of proteins secreted by the system, analysis of the inject some by electron microscopy, and determination of the prevalence of ETT-2 encoding genes in a large collection of EAEC. We will contribute to the knowledge of the parthenogenesis caused by this important path type in our country, by identifying putative new secreted virulence factors. (AU)