Completed genomes for isolated from ticks and quality controlled for motility phenotype.

Complete genomes of were sequenced with Illumina and PacBio technologies from low-passage isolates from ticks. These isolates were quality controlled for intact , a regulator of actin-based motility that is negatively selected for in culture. The Sheila Smith strain was re-sequenced using the same methodology.

Identification of an autotransporter peptidase of Rickettsia rickettsii responsible for maturation of surface exposed autotransporters.

Members of the spotted fever group rickettsia express four large, surface-exposed autotransporters, at least one of which is a known virulence determinant. Autotransporter translocation to the bacterial outer surface, also known as type V secretion, involves formation of a β-barrel autotransporter domain in the periplasm that inserts into the outer membrane to form a pore through which the N-terminal passenger domain is passed and exposed on the outer surface. Two major surface antigens of Rickettsia rickettsii, are known to be surface exposed and the passenger domain cleaved from the autotransporter domain.

Regulator of Actin-Based Motility (RoaM) Downregulates Actin Tail Formation by Rickettsia rickettsii and Is Negatively Selected in Mammalian Cell Culture.

The etiological agent of Rocky Mountain spotted fever, Rickettsia rickettsii, is an obligately intracellular pathogen that induces the polymerization of actin filaments to propel the bacterium through the cytoplasm and spread to new host cells. Cell-to-cell spread via actin-based motility is considered a key virulence determinant for spotted fever group rickettsiae, as interruption of , the gene directly responsible for actin polymerization, has been shown to reduce fever in guinea pigs. However, little is known about how, or if, motility is regulated by the bacterium itself.

Characterizing species interactions that contribute to biofilm formation in a multispecies model of a potable water bacterial community.

Microbial biofilms are ubiquitous in drinking water systems, yet our understanding of drinking water biofilms lags behind our understanding of those in other environments. Here, a six-member model bacterial community was used to identify the interactions and individual contributions of each species to community biofilm formation. These bacteria were isolated from the International Space Station potable water system and include , , , ( and , but all six species are common members of terrestrial potable water systems.

Choline Catabolism in Burkholderia thailandensis Is Regulated by Multiple Glutamine Amidotransferase 1-Containing AraC Family Transcriptional Regulators.

Unlabelled: Burkholderia thailandensis is a soil-dwelling bacterium that shares many metabolic pathways with the ecologically similar, but evolutionarily distant, Pseudomonas aeruginosa Among the diverse nutrients it can utilize is choline, metabolizable to the osmoprotectant glycine betaine and subsequently catabolized as a source of carbon and nitrogen, similar to P. aeruginosa Orthologs of genes in the choline catabolic pathway in these two bacteria showed distinct differences in gene arrangement as well as an additional orthologous transcriptional regulator in B. thailandensis In this study, we showed that multiple glutamine amidotransferase 1 (GATase 1)-containing AraC family transcription regulators (GATRs) are involved in regulation of the B.

Characterization of the GbdR regulon in Pseudomonas aeruginosa.

Pseudomonas aeruginosa displays tremendous metabolic diversity, controlled in part by the abundance of transcription regulators in the genome. We have been investigating P. aeruginosa's response to the host, particularly changes regulated by the host-derived quaternary amines choline and glycine betaine (GB).

SpoIVA and SipL are Clostridium difficile spore morphogenetic proteins.

Clostridium difficile is a major nosocomial pathogen whose infections are difficult to treat because of their frequent recurrence. The spores of C. difficile are responsible for these clinical features, as they resist common disinfectants and antibiotic treatment.

Mediator-regulated transcription through the +1 nucleosome.

Many genes are regulated at the level of a Pol II that is recruited to a nucleosome-free region upstream of the +1 nucleosome. How the Mediator coactivator complex, which functions at multiple steps, affects transcription through the promoter proximal region, including this nucleosome, remains largely unaddressed. We have established a fully defined in vitro assay system to delineate mechanisms for Pol II transit across the +1 nucleosome.

Identification of DNA-dependent protein kinase as a cofactor for the forkhead transcription factor FoxA2.

Forkhead factors are important regulators of animal development and homeostasis. They are among the earliest to bind quiescent genes, which they activate in conjunction with other transcription factors. Many liver-specific genes are under the control of FoxA2, a liver-enriched forkhead protein.

Inhibition of Bacillus anthracis and potential surrogate bacilli growth from spore inocula by nisin and other antimicrobial peptides.

The ability of nisin, synthetic temporin analogs, magainins, defensins, and cecropins to inhibit Bacillus anthracis, Bacillus cereus, Bacillus thuringiensis, Bacillus mycoides, and Bacillus subtilis growth from spore inocula was determined using well diffusion assays. Nisin, magainin II amide, and defensins were inhibitory in screening against B. anthracis Sterne or B.