Role of intimin-Tir interactions and the Tir-cytoskeleton coupling protein in the colonization of calves and lambs by Escherichia coli O157:H7

Intimin facilitates intestinal colonization by enterohemorrhagic Escherichia coli O157:H7; however, the importance of intimin binding to its translocated receptor (Tir) as opposed to cellular coreceptors is unknown. The intimin-Tir interaction is needed for optimal actin assembly under adherent bacteria in vitro, a process which requires the Tir-cytoskeleton coupling protein (TccP/EspF(U)) in E. coli O157:H7. Here we report that E. coli O157:H7 tir mutants are at least as attenuated as isogenic eae mutants in calves and lambs, implying that the role of intimin in the colonization of reservoir hosts can be explained largely by its binding to Tir. Mutation of tccP uncoupled actin assembly from the intimin-Tir-mediated adherence of E. coli O157:H7 in vitro but did not impair intestinal colonization in calves and lambs, implying that pedestal formation may not be necessary for persistence. However, an E. coli O157:H7 tccP mutant induced typical attaching and effacing lesions in a bovine ligated ileal loop model of infection, suggesting that TccP-independent mechanisms of actin assembly may operate in vivo.

Algunas preguntas y respuestas sobre el Convenio TIR

Recopila las consultas formuladas en los diferentes foros latinoamericanos en los que se ha considerado el Convenio Aduanero relativo al Transporte Internacional de Mercancías al amparo de los Cuadernos TIR (Convenio TIR).

Manual para la aplicación del Convenio TIR = Manual for the application of the TIR Convention

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Posibilidades para aprovechar la experiencia del Convenio TIR en el Istmo Centroamericano

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Convenio TIR: una respuesta al creciente desarrollo industrial de los países de América Latina

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Manual para la aplicación del convenio aduanero relativo al transporte internacional de mercancías al amparo de los cuadernos TIR (Convenio TIR)

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Manual para la aplicación del Convenio TIR = Manual for the application of the TIR Convention

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