by Eric L. Sutten, M.S. Washington State University August 2009 Chair: Wendy C. Brown Anaplasma marginale is an economically important tick-borne intraerythrocytic rickettsial pathogen of cattle that can cause fever, weight loss and death upon acute infection in naïve hosts. Immunization with isolated outer membrane (OM) fractions elicits protective immunity against infection, whereas immunizat...

From the analysis of 251 prokaryotic genomes stored in public databases, the 761,260 deduced proteins were used to reconstruct a complete set of bacterial proteic families. Using the new Overlap algorithm, we have partitioned the Protein Homology Network (PHN), where the proteins are the nodes and the links represent homology relationships. The algorithm identifies the densely connected regions...

objective: the brucella melitensis virb operon, encoding a type iv secretion system (t4ss), is required for intracellular replication and persistent infection in the mouse model. the product of the second gene of the virb operon, virb2, is predicted to be localized at the bacterial surface, where they could potentially interact with host cells. studies to date have focused on characterization o...

Many gram-negative pathogens use a type IV secretion system (T4SS) to deliver effector proteins into eukaryotic host cells. The fidelity of protein translocation depends on the efficient recognition of effector proteins by the T4SS. Legionella pneumophila delivers a large number of effector proteins into eukaryotic cells using the Dot/Icm T4SS. How the Dot/Icm system is able to recognize and co...

Legionella pneumophila, the causative agent of a severe pneumonia termed Legionnaires' Disease, survives and replicates within both protozoan hosts and human alveolar macrophages. Intracellular survival is dependent upon secretion of a plethora of protein effectors that function to form a replicative vacuole, evade the endocytic pathway and subvert host immune defenses. Export of these factors ...

Abstract Plant growth-promoting rhizobacteria (PGPR) contain various biocontrol bacteria with broad-spectrum antimicrobial activity, and their single species has been extensively applied to control crop diseases. The development of complex community by mixing two or more PGPR members together is a promising strategy enlarge the efficacy scope biocontrol. However, an effective method assess natu...

Genetic exchange by conjugation is responsible for the spread of resistance, virulence, and social traits among prokaryotes. Recent works unraveled the functioning of the underlying type IV secretion systems (T4SS) and its distribution and recruitment for other biological processes (exaptation), notably pathogenesis. We analyzed the phylogeny of key conjugation proteins to infer the evolutionar...

Legionella pneumophila is a Gram-negative bacterium that replicates within human alveolar macrophages by evasion of the host endocytic pathway through the formation of a replicative vacuole. Generation of this vacuole is dependent upon the secretion of over 275 effector proteins into the host cell via the Dot/Icm type IVB secretion system (T4SS). The type IV coupling protein (T4CP) subcomplex, ...

Horizontal gene transfer shapes the genomes of prokaryotes by allowing rapid acquisition of novel adaptive functions. Conjugation allows the broadest range and the highest gene transfer input per transfer event. While conjugative plasmids have been studied for decades, the number and diversity of integrative conjugative elements (ICE) in prokaryotes remained unknown. We defined a large set of p...