Thesis (Ph. D.)--University of Washington, 2002. / Includes bibliographical references (leaves 159-186).

Pathogenic bacteria colonise their host animals by means of a complex set of interactions. The host defensive mechanisms attack foreign microorganisms and attempt to rid the animal of the invaders, while the bacteria express a variety of functions to ensure their survival under adverse conditions, some of which damage the host and cause the clinical symptoms of disease. Adhesins are the bacterial structures which mediate adherence to specific host tissues and therefore permit the colonisation of areas from which the bacteria would normally be removed. T4. I have genetically cloned and analysed an adhesin from a pathogenic strain of Escherichia coli isolated from a child with enteritis. The genetic information was transferred to laboratory strains of E. coli and was expressed under similar conditions as in the parent strain, generating material with the same adherence and antigenic properties. Thus, the cloned genes enabled laboratory strains to adhere to human colon, but not to duodenum, in the same manner as the parent. This probably accounts in large part for the tissue specificity of the pathogen which caused dysentery-like symptoms consistent with colonisation of, and damage to, the colon. The cloned genes encoded the synthesis of the adhesin as fine fibrils ('fimbriae') on the bacterial surface, approximately 2 nm in diameter. The 14,000 dalton protein subunits were assembled into very high molecular weight aggregates and were purified by size fractionation. The genetic determinant occupied about 6,000 basepairs of DNA, indicating a system of genes for the synthesis, export and assembly of functional adhesin. The genetic map was very similar to those of adhesins from another enteritis isolate and a urinary tract pathogen, suggesting an evolutionary relationship between these E. coli strains. However, the protein subunits of the three adhesins appear to differ, indicating a degree of divergence.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2001. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Missouri--Columbia, 2000. / "December 2000." Typescript. Vita. Includes bibliographical references (leaves 120-131). Also available on the Internet.

A leptospirose é uma zoonose mundial causada por espiroquetas patogênicas do gênero Leptospira, que colonizam os túbulos renais de animais domésticos e silvestres e são liberadas ao ambiente externo pela urina. Neste estudo avaliou-se a interação de seis prováveis lipoproteínas de membrana externa de leptospira com as proteínas do hospedeiro: colágeno I, colágeno IV, elastina, fibrinogênio, fibronectina celular e plasmática, laminina e plasminogênio. Os experimentos de adesão demonstraram que as proteínas recombinantes Lp21, Lp22 e Lsa30 apresentaram interação com os componentes do hospedeiro de maneira dose-dependente. Estas aderiram à fibronectina plasmática e laminina, além destes, a Lp21 e a Lp22 interagiram com plasminogênio, a Lp22 e a Lsa30 interagiram com colágeno IV. A Lp22 aderiu à elastina e ao fibrinogênio. No estudo de conservação gênica, os genes que codificam estas proteínas foram observados somente nas Leptospiras patogênicas. Portanto estas proteínas devem contribuir na adesão aos tecidos do hospedeiro na patogênese da Leptospira. / Leptospirosis is a worldwide zoonosis caused by pathogenic spirochetes of the genus Leptospira that colonize the renal tubules of wild and domestic animals and are excreted in the environment by their urine. The aim of this work was to study the interaction of six leptospiral probable outer-membrane lipoproteins with host proteins: collagen I, collagen IV, elastin, fibrinogen, cellular fibronectin, plasma fibronectin, laminin, and plasminogen. The binding experiments demonstrated that the recombinant proteins showed interaction with host components in a dose-dependent manner were Lp21, Lsa30 and Lp22. These proteins adhered to plasma fibronectin and laminin, in addition to these components, Lp21 and Lp22 interacted with plasminogen, Lp22 and Lsa30 interacted with collagen IV. The Lp22 adhered to elastin and fibrinogen. The genes encoding the probable lipoproteins were found only in pathogenic Leptospira. These results demonstrated that these proteins may contribute in the adhesion to host tissues, in the pathogenesis of Leptospira.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 98-113).

Diss. (sammanfattning) Umeå : Umeå universitet, 2009. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

A leptospirose é uma zoonose mundial causada por espiroquetas patogênicas do gênero Leptospira, que colonizam os túbulos renais de animais domésticos e silvestres e são liberadas ao ambiente externo pela urina. Neste estudo avaliou-se a interação de seis prováveis lipoproteínas de membrana externa de leptospira com as proteínas do hospedeiro: colágeno I, colágeno IV, elastina, fibrinogênio, fibronectina celular e plasmática, laminina e plasminogênio. Os experimentos de adesão demonstraram que as proteínas recombinantes Lp21, Lp22 e Lsa30 apresentaram interação com os componentes do hospedeiro de maneira dose-dependente. Estas aderiram à fibronectina plasmática e laminina, além destes, a Lp21 e a Lp22 interagiram com plasminogênio, a Lp22 e a Lsa30 interagiram com colágeno IV. A Lp22 aderiu à elastina e ao fibrinogênio. No estudo de conservação gênica, os genes que codificam estas proteínas foram observados somente nas Leptospiras patogênicas. Portanto estas proteínas devem contribuir na adesão aos tecidos do hospedeiro na patogênese da Leptospira. / Leptospirosis is a worldwide zoonosis caused by pathogenic spirochetes of the genus Leptospira that colonize the renal tubules of wild and domestic animals and are excreted in the environment by their urine. The aim of this work was to study the interaction of six leptospiral probable outer-membrane lipoproteins with host proteins: collagen I, collagen IV, elastin, fibrinogen, cellular fibronectin, plasma fibronectin, laminin, and plasminogen. The binding experiments demonstrated that the recombinant proteins showed interaction with host components in a dose-dependent manner were Lp21, Lsa30 and Lp22. These proteins adhered to plasma fibronectin and laminin, in addition to these components, Lp21 and Lp22 interacted with plasminogen, Lp22 and Lsa30 interacted with collagen IV. The Lp22 adhered to elastin and fibrinogen. The genes encoding the probable lipoproteins were found only in pathogenic Leptospira. These results demonstrated that these proteins may contribute in the adhesion to host tissues, in the pathogenesis of Leptospira.

No description available.