Details

Autor(en) / Beteiligte

• Heithoff, Douglas M.
• Conner, Christopher P.
• Hanna, Philip C.
• Julio, Steven M.
• Hentschel, Ute
• Mahan, Michael J.

Titel

Bacterial Infection as Assessed by in vivo Gene Expression

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 1997-02, Vol.94 (3), p.934-939

Ort / Verlag

United States: National Academy of Sciences of the United States of America

Erscheinungsjahr

1997

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• In vivo expression technology (IVET) has been used to identify > 100 Salmonella typhimurium genes that are specifically expressed during infection of BALB/c mice and/or murine cultured macrophages. Induction of these genes is shown to be required for survival in the animal under conditions of the IVET selection. One class of in vivo induced (ivi) genes, iviVI-A and iviVI-B, constitute an operon that resides in a region of the Salmonella genome with low G+C content and presumably has been acquired by horizontal transfer. These ivi genes encode predicted proteins that are similar to adhesins and invasins from prokaryotic and eukaryotic pathogens (Escherichia coli [tia], Plasmodium falciparum [PfEMP1]) and have coopted the PhoPQ regulatory circuitry of Salmonella virulence genes. Examination of the in vivo induction profile indicates (i) many ivi genes encode regulatory functions (e.g., phoPQ and pmrAB) that serve to enhance the sensitivity and amplitude of virulence gene expression (e.g., spvB); and (ii) the biochemical function of many metabolic genes may not represent their sole contribution to virulence; (iii) the host ecology can be inferred from the biochemical functions of ivi genes; and (iv) nutrient limitation plays a dual signaling role in pathogenesis: to induce metabolic functions that complement host nutritional deficiencies and to induce virulence functions required for immediate survival and spread to subsequent host sites.