en Chitosan-Based Intranasal Vaccine against Escherichia coli O157:H7 Related Fields Related Fields مقاله کامل Full Length/Original Article <p style="direction: ltr "><strong>Background:</strong><em> Enterohemorrhagic</em> <em>Escherichia coli</em> (EHEC) O157:H7 is an infectious zoonotic pathogen causing human infections. These infections, in some cases, can lead to hemolytic uremic syndrome and its life-threatening complications and even death worldwide. The first intimate bacterial adhesion, intimin (I), with its own receptor translocated intimin receptor (Tir) and<em> E. coli</em> secreted protein A, acting as Tir conduit, are highly immunogenic proteins for vaccine development against <em>E. coli</em> O157:H7. <strong>Methods:</strong> A chimeric trivalent recombinant protein was previously found to be a suitable strategy for developing vaccines against <em>E. coli</em> O157:H7. In this study, the recombinant EIT (rEIT) was used to design a protective EHEC nasal nanovaccine. Chitosan and its water-soluble derivative, trimethylated chitosan (TMC), as muco-adhesive biopolymers, are good candidates for preparation of nanovaccines.&nbsp; Using the&nbsp;electrospraying technique, as a novel method, we could obtain particles&nbsp;of rEIT loaded with chitosan and TMC on a nanometer scale. Mice were immunized with intranasal administration or intrapretoneal injection of rEIT. <strong>Results</strong>: The rEIT-specific immune responses (IgG and IgA) were measured by&nbsp;indirect ELISA. Only nasal administration of chitosan electrospray and TMC formulation produced significant secretion IgA. Intranasal administration of nanovaccine reduced the duration of bacterial fecal shedding&nbsp;on mice challenged with <em>E.</em><em> coli</em> O157:H7. <strong>Conclusion:</strong> Since development of mucosal vaccines for the prevention of infectious diseases requires efficient antigen delivery therefore, this research could be a new strategy for developing vaccine against <em>E. coli</em> O157:H7.</p> Enterohemorrhagic Escherichia coli, Nanoparticles, Intranasal vaccination 97 108 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-589&slc_lang=en&sid=1 Tahere Doavi No Seyed Latif Mousavi slmousavi@shahed.ac.ir Yes Mehdi Kamali No Jafar Amani No Mahdi Fasihi Ramandi No