Análise da expressão e caracterização funcional da hemaglutinina temperatura sensível de Escherichia coli

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Escherichia coli is an important agent of extra-intestinal infections both in humans and animals alike. In poultry, it is responsible for significant economic loss, being known as the pathogenic avian E. coli (APEC); and it causes colibacillosis, which starts as an infection of the respiratory tract evolving to airsacculitis, pericarditis, perihepatitis and septicemia. Several virulence genes are involved, among which tsh. The tsh gene codifies the autotransporter protein temperature sensitive hemagglutinin (Tsh), which has hemagglutinating and proteolytic activities. Tsh is synthesized as 140 kDa precursor protein, whose processing results in 106 kDa passenger domain (Tshs) and 33 kDa beta-domain (Tshb). In our study, we observed that these proteins presence is dependent on temperature and on the medium utilized for bacterial growth. We also verified that both the recombinant Tsh (140 kDa) and the pellets from wild sample APEC 13, which contain Tshb (33 kDa), agglutinated chicken erythrocytes. Both the recombinant Tsh (140kDa) and the supernatants from APEC 13, which contain Tshs (106 kDa), caused proteolysis of mucin. Chicken anti-Tsh serum inhibited the hemagglutinating activity of strains APEC 13 and recombinant E. coli BL21/pET101-tsh, and it also inhibited the mucinolytic activity of Tsh protein. The proof of Tsh protein mucinolytic activity was achieved by means of SDS-PAGE in gels copolymerized with mucins from different sources.

ASSUNTO(S)

escherichia coli escherichia coli microbiologia microbiology

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