“Escherichia coli productora de toxina Shiga (STEC): respuesta inmune local, colonización intestinal y daño sistémico”.

PALERMO, MS

Asociación Argentina de Microbiología, Bs AS

Taller; Taller “Inmunidad de Mucosas”,; 2007

Grupo de Trabajo de Microbiología general de la Asociación Argentina de Microbiología:

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 infections are considered a public health problem in both, developed and developing countries, because its increasing incidence and the severity of clinical presentation. Near to 10% of infected patients may develop complications such as hemolytic uremic syndrome (HUS) characterized by acute renal failure, thrombocytopenia and hemolytic anemia. The precise sequence of events leading to HUS is still incompletely understood. Since the lack of a reproducible small animal model for EHEC infections, in vivo studies examining EHEC-host early interactions are limited and insufficient.  The aim of this study was to characterize the weaned BALB/c mouse as a model of E. coli O157:H7 infection. We reported that human Stx2-producing EHEC strains can adhere to the intestinal epithelium of weaned BALB/c mice, and following local damage lead to systemic disease and death in a percentage of infected mice. The lethality of EHEC strain is closely dependent on age of mice, and it is related to bacterial ability to colonize intestine and to produce Stx2. We conclude that the weaned BALB/c mouse can be used as a small animal model to study host early responses, the role of bacterial pathogenic factors in the induction of systemic disease, and it will also provide a tool for evaluation of therapeutic or vaccine approaches.