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| Author(s): |
Cristiane Mobilon
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2012-05-30 |
| Examining board members: |
Wanderley Dias da Silveira;
Marcelo Brocchi;
Vasco Ariston de Carvalho Azevedo;
Marcelo Palma Sircili;
Waldir Pereira Elias
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| Advisor: | Wanderley Dias da Silveira; Eliana Guedes Stehling |
| Abstract | |
Shigellosis is a severe intestinal infection caused by Gram-negative bacteria which belongs to the genus Shigella. It is a pathology with high incidence and it is known that 99% of cases occur in underdevelopment countries. Among these cases, 69% of them affect children under 5 years old. The high incidence of Shigella in underdevelopment countries, is mainly atribbuted to substandard hygiene, unsafe water supplies, subnutrition and antibiotic high cost. The predominant mode of transmission is by fecal-oral contact. The pathogenicity mechanisms described for Shigella species include several virulence genes, most of them been encoded in a plasmid (pINV) with 220 kb. This plasmid encodes 2 important operons which are essential for the invasive phenotype: the operon ipa and the operon mxi-spa. The ipa operon encodes the invasion plasmid antigens called IpaA, IpaB, IpaC and IpaD, which are effector proteins required for the bacteria invasion process. The mxi-spa operon together with IpaB, IpaC and IpaD are essential to epithelial in vitro cell invasion. It is also known that these proteins or invasion plasmid antigens may be highly immunogenic. During the development of this work, ipaC gene was cloned in the plasmidial vector pET28a for expression in Escherichia coli and in constitutive vectors for lactic acid bacteria to prove its immunogenic importance. Furthermore it was verified that the antibodies produced in response to IpaC protein were able to inhibit Shigella flexneri adhesion and invasion in in vitro cultured cells, confirming its important hole in bacteria invasion process and its possible usage in vaccine development against shigellosis (AU) | |